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KOMPENDIUM KAJIAN LINGKUNGAN
DAN PEMBANGUNAN
BIODEGRADASI &
COMPOSTING
Dikoleksi oleh: Soemarno, pdklp-ppsub 2012
DEKOMPOSISI BAHAN ORGANIK
Bahan organik merupakan bahan-bahan yang dapat diperbaharui, didaur ulang, dirombak oleh bakteri-bakteri tanah menjadi unsur yang dapat digunakan oleh
tanaman tanpa mencemari tanah dan air. Bahan organik tanah merupakan penimbunan dari sisa-sisa tanaman dan
binatang yang sebagian telah mengalami pelapukan dan pembentukan kembali. Bahan organik yang sedang mengalami dekomposisi aktif akan menjadi
mangsa bagi jasad mikro. Sebagai akibatnya bahan tersebut berubah terus dan tidak mantap sehingga harus selalu diperbaharui melalui penambahan sisa-sisa
tanaman atau binatang.
Komposisi Biomassa / Bahan Organik
Menurut Waksman (1948), biomass bahan organik yang berasal dari biomass tumbuhan, terdiri dari: (1) air (75%) dan (2) biomass kering (25%).
Komposisi biokimia bahan organik dari biomass kering tersebut, terdiri dari: karbohidrat (60%), lignin (25%), protein (10%), dan lemak, lilin dan tanin (5%).Karbohidrat penyusun biomass kering tersebut, terdiri dari: gula dan pati (1% -
s/d- 5%), hemiselulosa (10% -s/d- 30%), dan selulosa (20% -s/d- 50%).Berdasarkan kategori unsur hara penyusun biomass kering, terdiri dari: Karbon
(C = 44%), Oksigen (O = 40%), Hidrogen (H = 8%), dan Mineral (8%).
contoh komposisi kimiawi jerami padi dan serealia. Selulose dan hemiselulose merupakan komponen utama dari jerami padi.
BioDegradasi Residu Tanaman
Proses dekomposisi bahan organik melalui 3 reaksi, yaitu:1.Reaksi enzimatik atau oksidasi enzimatik, yaitu: reaksi oksidasi senyawa hidrokarbon yang terjadi melalui reaksi enzimatik menghasilkan produk akhir berupa karbon dioksida (CO2), air (H2O), energi dan panas. 2.Reaksi spesifik berupa mineralisasi dan atau immobilisasi unsur hara essensial berupa hara nitrogen (N), fosfor (P), dan belerang (S).3.Pembentukan senyawa-senyawa baru atau turunan yang sangat resisten berupa humus tanah.
Bahan organik residu tanaman mengandung 15-60 % sellulose, 10-30 % hemicel lulose, 5-30 % lignin, 2-15 % protein dan 10 % gula, asam amino dan asam-asam organik. Sellulose terdapat dalam bentuk semi-crystalline dengan berat molekul 106 dan mempunyai unit-unit glucose dengan ikatan
B(1-4). Rantai-rantai glucose diikat bersama dengan ikatan-hidrogen.
Kompleks enzim Cellulase menghancurkan sellulose menjadi disaccharide-cel lobiose yang dihidrolisis lebih lanjut oleh ensim cellobiase menjadi
glucose. Hemicelluloses merupakan polimer dari hexoses, pentoses dan kadangkala asam-asam uronat, bersama dengan monomer seperti xylose
dan man nose. Pectin merupakan salah satu contoh dari hemicelluloses dan merupakan komponen penting dari middle-lamella pada dinding sel. Pectin dapat dihancurkan oleh enzim pectinase yang merupakan kompleks dari
beberapa jenis enzim.
Urutan kemudahan dekomposisi dari berbagai bahan penyusun bahan organik tanah dari yang terdekomposisi paling cepat sampai dengan yang terdekomposisi paling
lambat, adalah sebagai berikut:1.gula, pati, dan protein sederhana,2.protein kasar (protein yang leih kompleks),3.hemiselulosa,4.selulosa,5. lemak, minyak dan lilin, serta6.lignin.
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
Kompos adalah hasil penguraian parsial/tidak lengkap dari campuran bahan-bahan organik yang dapat dipercepat secara artifisial oleh populasi berbagai macam mikroba dalam kondisi lingkungan yang hangat, lembap, dan aerobik
atau anaerobik.
Pengomposan adalah proses dimana bahan organik mengalami penguraian secara biologis, khususnya oleh mikroba-mikroba yang memanfaatkan bahan
organik sebagai sumber energi. Membuat kompos adalah mengatur dan mengontrol proses alami tersebut agar kompos dapat terbentuk lebih cepat. Proses ini meliputi membuat campuran bahan yang seimbang, pemberian air yang cukup, mengaturan aerasi, dan penambahan aktivator pengomposan.
Proses PengomposanProses pengomposan akan segera berlansung setelah bahan-bahan mentah dicampur. Proses pengomposan secara sederhana dapat dibagi menjadi dua
tahap, yaitu tahap aktif dan tahap pematangan. Selama tahap-tahap awal proses, oksigen dan senyawa-senyawa yang mudah terdegradasi akan
segera dimanfaatkan oleh mikroba mesofilik. Suhu tumpukan kompos akan meningkat dengan cepat. Demikian pula akan diikuti dengan peningkatan pH kompos. Suhu akan meningkat hingga di atas 50o - 70o C. Suhu akan tetap tinggi selama waktu tertentu. Mikroba yang aktif
pada kondisi ini adalah mikroba Termofilik, yaitu mikroba yang aktif pada suhu tinggi. Pada saat ini terjadi dekomposisi/penguraian bahan organik yang
sangat aktif. Mikroba-mikroba di dalam kompos dengan menggunakan oksigen akan menguraikan bahan organik menjadi CO2, uap air dan panas.
Setelah sebagian besar bahan telah terurai, maka suhu akan berangsur-angsur mengalami penurunan.
Pada saat ini terjadi pematangan kompos tingkat lanjut, yaitu pembentukan komplek liat humus. Selama proses pengomposan akan terjadi penyusutan
volume maupun biomassa bahan. Pengurangan ini dapat mencapai 30 – 40% dari volume/bobot awal bahan.
BAHAN ORGANIK DAN KOMPOS
BAHAN ORGANIK TANAH (BOT)BOT = SOM - organic matter in a soil that cannot be recognized as plant material under a light microscope.
* Biota hidup dalam tanah. (Mikroba Tanha)
* Residu tumbuhan, binatang dan mikroba yang sedang mengalami dekomposisi.
* Bahan organik yang reistem terhadp dekomposisi lanjut.
Biogeochemical cycling C SOM ~1 x 1015 kg +
CO2 (atmosphere) ~ 5 x 1014kgliving organisms ~ 5 x 1014 kg.
1019 kg C on earth most in sediments and rocks, fossil fuels, and DIC & POM
in the oceans
.
.
.
.
Consider residence times.The most significant input to SOM is plant residues;
~ 11 tonne ha-1 yr-1 for tropical rain forests, TR ~ 1.4 - 14 yr.~ 6 tonne ha-1 yr-1 for temperate forests, TR ~ 2.5 - 25 yr.
~3 tonne ha-1 yr-1 for temperate grasslands, TR ~ 5 - 50 yr, and <1 tonne ha-1 yr-1 for deserts, >15 – 150 yr.
60 - 70% of this comes from plant roots (rhizo derived), 70% of plant residues decompose within 1 year. Most of the C in soils is in
the resistate (humic) form (~70%).
At 1 – 10(vol)% C in the soil, 1 hectare (100m x 100m; 2.47 acres) to a depth of 15 cm (plough depth) has about 15 – 150 tonnes C.
BAHAN ORGANIK TANAH
Functions of SOM:
1. Binds particles to form soil aggregates (hinders soil erosion;
soils need approximately 4% C to be structurally stable).
2. Degrading organics a source of nutrients to soil - N, P, S, B,
metals (Cu, Zn, Mg, Ca, Fe, Mo, Mn).
3. Contributes to soil pH.
4. Has a high Cation Exchange Capacity - ~300meq/100g SOM
(2:1 clays of 100meq/100 g clay, 1:1 clay 10meq/100g clay).
5. Controls transport/availability of metals via complexation &
adsorption reactions – Kf large for humics, smaller for lower
MW carboxylic acids, amino acids, and organic bases
(NTA3- as model for complexation).
6. Enhances water retention.
7. Gives soil a darker colour (heat adsorption/retention).
At 1 – 10(vol)% C in the soil, 1 hectare (100m x 100m; 2.47 acres) to a depth of 15 cm (plough depth) has about 15 – 150 tonnes C.
BAHAN ORGANIK TANAH
Peranan bahan organik terhadap perubahan sifat fisik tanah, meliputi:1.Stimulan terhadap granulasi tanah,2.Memperbaiki struktur tanah menjadi lebih remah,3.Menurunkan plastisitas dan kohesi tanah,4.Meningkatkan daya tanah menahan air sehingga drainase tidak berlebihan, kelembaban dan temperatur tanah menjadi stabil,5.Mempengaruhi warna tanah menjadi coklat sampai hitam,6.Menetralisir daya rusak butir-butir hujan,7.Menghambat erosi, dan8.Mengurangi pelindian (pencucian/leaching).
* Sugars & starches - foods.* Proteins (10%)* Cellulose & hemicelluloses - structural materials.* Lipids - fats/waxes/steroids/etc. (5%)*Lignins - structural materials (25%)
BAHAN ORGANIK TANAH.
SOMMineralized organics
(humics, peat, oils, coal).
heat
Nutrients, trace elements,
inorganics
CO2, CH4, H2O
SOM45%
inorganic
Air20 - 30%
Water 20 - 30%
Soil
Increasingly resistant to weathering
60%
44% C40% O8% H
8% ashwt %
C6H12.8O6
25% dry matter
Degrading plant materials (30%),
0 - 10%
& physically and chemically resistant organics (70%)
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/17118642 ….. Diunduh 28/4/2012
Sawdust has been proven to be a good bulking agent for sludge composting;
however, studies on the most suitable ratio of sludge:sawdust for sludge composting and on the influence of the sludge nature (aerobic or anaerobic) on the composting
reaction rate are scarce.
Aerobic sludge piles showed significantly higher microbial activity than those of anaerobic sludge, organic matter mineralization rates being higher in the AS
mixtures. The lowest thermophilic temperatures during composting were registered when the anaerobic sludge was mixed with sawdust at 1:1 ratio, suggesting the
presence of substances toxic to microorganisms. This mixture also showed the lowest decreases of ammonium during composting. All this matched with the inhibitory effect on the germination of Lepidium sativum seeds of this mixture at the first stages of composting, and with its low values of microbial basal respiration. However, the ANS+WS 1:3 compost developed in a suitable way;
the higher proportion of bulking agent in this mixture appeared to have a diluting effect on these toxic compounds.
Both the proportions assayed allowed composting to develop adequately in the case of the aerobic sludge mixture, yielding suitable composts for agricultural use.
However, the ratio 1:1 seems more suitable because it is more economical than the 1:3 ratio and has a lower dilution effect on the nutritional components of the
composts.
In the case of the anaerobic sludge with its high electrical conductivity and ammonium content, and likely presence of other toxic and phytotoxic substances,
the 1:3 ratio is to be recommended because of the dilution effect.
. Waste Manag. 2007;27(10):1317-27. Epub 2006 Nov 21.Composting anaerobic and aerobic sewage sludges using two proportions of
sawdust.Banegas V, Moreno JL, Moreno JI, García C, León G, Hernández T.
In this study two different sewage sludges (aerobic, AS, and anaerobic, ANS)
were composted with wood sawdust (WS) as bulking
agent at two different ratios (1:1 and 1:3 sludge:sawdust,
v:v).
1 - 4 glycosidic linkages
* Long unbranched chains of up to 15,000 glucose units; alternate units turned over – polysacharides.
* Up to 40 chains held together by H-bonds to form an insoluble, rigid, fibers which serve as the structural materials in the cell
walls of plants and some animals.
*Approximately 50% of C in the biosphere is cellulose. Very slowly degraded.
D(+) glucopyranose D(+) glucopyranose
BAHAN ORGANIK TANAH (bot) :
Carbohydrates (CH2O) polyhydroxyaldehydes or ketones or substances that hydrolyse to give these (Solomons,
Fundimentals of Organic Chemistry, 1994, Chapter 22).
oth the hemiacetal OH & the C6 CH2OH
on the same face.
Sugars are mono- or di-saccharides
Polymerize (dehydration) to give cellulose
Polymerize to give starch
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/16356705 ….. Diunduh 28/4/2012
Changes in the chemical and chemical-structural composition of the organic matter of
two different sewage sludges (aerobic and anaerobic) mixed with sawdust (1:1 and 1:3, v/v) during composting were determined by
monitoring chemical and microbiological parameters as well as by pyrolysis-gas
chromatography.
Microbial activity as measured by microbial respiration (CO(2) evolved from compost samples during incubation) also decreased with composting, reflecting the more stable character of the resulting compost. No major differences were observed
between the four composts studied as regards their chemical-structural characteristics. The acetonitrile, acetic acid and phenol pyrolytic fragment tended to increase with composting. Although the final composts were more aromatic in nature
than the starting materials, a low degree of humification was observed in all four composts studied, as determined by their high proportion of polysaccharides and
alkyl compounds. For this reason, the relationship between pyrolytic fragments, such as
benzene/toluene or benzene+toluene/pyrrol+phenols, which are used as indices of humification for soil organic matter, are not of use for such poorly evolved sludge
composts; instead, ratios that involve carbohydrate derivatives and aromatic compounds, such as furfural+acetic/benzene+toluene or acetic/toluene, are more
sensitive indices for reflecting the transformations of these materials during composting. Both the chemical and microbiological parameters and pyrolytic analysis provided valuable information concerning the nature of the compost's organic matter
and its changes during the composting process.
Waste Manag. 2006;26(12):1370-6. Epub 2005 Dec 13.Changes in organic matter composition during composting of two digested
sewage sludges.Hernández T, Masciandaro G, Moreno JI, García C.
Composting was carried out in periodically turned outdoor
piles, which were sampled for analysis 1, 30, 60 and 90 days
after the beginning of the composting process. Both
volatile organic matter and the water soluble C fraction
decreased during composting, indicating that the more labile C fractions are mineralized during
the process.
Starch - a major nutrient for animals.
Enzymically assisted digestion involves the hydrolysis of
1 - 4 glycosidic links to produce oligiosaccharides (a few
linked monosaccharides containing the 1-6 linkages).
Further hydrolysis produces monosaccharides.
D(+) glucopyranose D(+) glucopyranose
Polymerize to give starch: the food reserve in plants
1 - 6 glucosidic
linkage
1 - 4 glucosidic
linkage
BAHAN ORGANIK TANAH (bot):
Carbohydrates.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/17125814 ….. Diunduh 28/4/2012
Aerobic decomposition and stabilization of organic matter during the composting of waste materials is primarily due to the
biochemical transformation of water-soluble compounds in the liquid phase
by the microbial biomass.
Accordingly, chemical analysis as well as UV absorption, and 1H and 13C-NMR spectroscopy of
samples collected during the industrial composting of urban waste revealed microbial induced transformation
of water-extractable organic matter over time.
The chemical composition changed from labile, hydrophilic, plant-derived organic compounds in the
beginning to predominately stable, hydrophobic moieties comprising lignin-derived phenols and microbially-
derived carbohydrates at later stages of composting.
. Chemosphere. 2007 Feb;66(11):2166-76. Epub 2006 Nov 27.Changes in the chemical composition of water-extractable organic matter during composting: distribution between stable and labile organic matter
pools.Said-Pullicino D, Kaiser K, Guggenberger G, Gigliotti G.
For this reason water-soluble organic matter represents the most
active fraction of compost, both biologically and chemically, and thus should directly reflect the
biochemical alteration of organic matter. This work aims to elucidate the microbial-mediated processes responsible for the distribution of soluble organic matter between
stable and labile pools with composting time.
Soil Organic matter (SOM) :- Lignins
25% of SOM
Highly aromatic polymers (MW - 2000 - 106) based on phenylpropane monomers.
Many functional groups, acidic, colour,
high complexing capacity.
The woody tissues of plants and the major material binding cells together.
Water repellent.
As trees grow it impregnates the cells and kills them by stopping water and nutrient transfer across the cell walls.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/15491829 ….. Diunduh 28/4/2012
In this study changes in the properties of natural organic matter (NOM) were
studied during composting of sewage sludge in a laboratory experiment using
the pile method.
On the basis of chemical analyses, 53 days of composting sewage sludge with structural material can be divided into three phases:
(i) domination of rapid decomposition of non-humic, easily biodegradable organic matter (two to three weeks), (ii) domination of organic matter
humification and formation of polycondensed, humic-like substances (the next two weeks), (iii) stabilization of transformed organic material and
weak microbial activity.
Spectroscopic characterization (13C NMR) of compost humic acids reveals changes in their structures during maturation. The changes are
highly correlated with the processes taking place in bulk compost.
Bioresour Technol. 2005 Mar;96(4):471-8.Characterization of natural organic matter (NOM) derived from sewage sludge
compost. Part 1: chemical and spectroscopic properties.Zbytniewski R, Buszewski B.
Typical physicochemical parameters were measured
during 53 days of composting including humic fractions.
The effects of humification on the molecular properties of
humic acids (HA) were investigated by 13C CP/MAS
NMR spectroscopy.
* The most diverse of the biopolymers (starches, proteins and nucleic acids)
* Functions: hormones, enzymes, antibodies, haemoglobin, skin, hair,
bone, muscles, tendons, ...
* Provide N, S on degradation
* High molecular weight polyamides: 22 -amino acids. MW > 104.
KANDUNGAN PROTEIN BOT:
10% BOT
cholesterol
- H2O
Waxes: esters of fatty acids and alcohols
Terpenes: molecules based on 2, 3, 4 or 5 isoprene {C=C(C)C=C} units.
Essential oils, natural rubbers, carotenes.
Steroids
(Solomons, chapter 24, p 974-
5)
BAHAN ORGANIK TANAH : Lipids = 5% SOM
Operationally defined as the compounds of plants that can be extracted into non-polar solvents – very diverse.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19560348 ….. Diunduh 28/4/2012
Four types of compost, consisting of mixtures of Acacia dealbata (A) with
sewage sludge (SS) were studied in a laboratory reactor.
All the studied parameters were influenced by the bulking amount used. The highest profile temperature measured was for the A/SS 1/2 (w/w)
mixture that reached a maxima temperature of 67 degrees C and lower maximum temperatures of 52, 48 and 46 degrees C were observed for
A/SS 1/3, 1/1 and 1/0 composts, respectively.
The kinetic model used showed that a descent of sewage sludge in the composting mixtures favored the enzyme-substrate affinity. However, an
increase in depending on the parameters of the process factors was observed when the sewage sludge ratio was increased in mixtures.
The optimal amounts of sewage sludge for co-composting with Acacia indicate that moderate amounts of sludge (1/1) would be the best
compromise.
. Bioresour Technol. 2009 Dec;100(23):5827-33. Epub 2009 Jun 26.Influence of bulking agent on sewage sludge composting process.
Yañez R, Alonso JL, Díaz MJ.
Composting time was 80 days and parameters monitored over this period included
temperature, organic matter, pH, CO(2), O(2), C/N ratio,
Kjeldahl-N, as well as maturity indexes.
BAHAN ORGANIK TANAH: LEMAK
Triacylglycerols: Animal fats and vegetable oils.
Formed by condensation between glycerol and
various fatty acids
(c12 – C20).
Energy reserves in animals.
Phospholipids: One fatty acid replaced by a phosphate linked to an alcohol - OPO(OH)OR".
Eg of R". -OCH2CH2N(CH3)3+ - choline;
Polar and non-polar ends; sources of P and N on degradation.
Acyl groups can be saturated, unsaturated or polyunsaturated.
Oils > 70% unsaturated acyl groups. Fats < 40% unsaturated.
Nucleic acids: (Solomons, Chapter 25, p1017) polymers of nucleotides (phosphate, ribose or deoxyribose and a purine or a
pyrimidine base. Degrade to a base, phosphate and a sugar.
a purine : adenine
a pyrimidine base: thyamine
pentose - phosphate backbone
guanine
Adenosine triphosphate (ATP): energy transmitting
molecules. Lose PO43- to give
ADP and AMP and energy for biomolecule fromation.
BAHAN ORGANIK TANAH : NUCLEIC ACIDS
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19584243 ….. Diunduh 28/4/2012
Landfill gas containing methane is produced by anaerobic
degradation of organic waste.
. The methane oxidation process, which is governed by several environmental factors, can be exploited in engineered systems
developed for methane emission mitigation.
Mathematical models that account for methane oxidation can be used to predict methane emissions from landfills.
Additional research and technology development is needed before methane mitigation technologies utilizing microbial
methane oxidation processes can become commercially viable and widely deployed.
Waste Manag Res. 2009 Aug;27(5):409-55. Epub 2009 Jul 7.Microbial methane oxidation processes and technologies for mitigation of
landfill gas emissions.Scheutz C, Kjeldsen P, Bogner JE, De Visscher A, Gebert J, Hilger HA,
Huber-Humer M, Spokas K.
Methane is a strong greenhouse gas and landfills
are one of the major anthropogenic sources of atmospheric methane.
Landfill methane may be oxidized by methanotrophic microorganisms in soils or waste materials utilizing
oxygen that diffuses into the cover layer from the
atmosphere
BAHAN ORGANIK TANAH : The Resistant Fraction.
70% of SOM is the chemically & physically resistant organics.
Derived in some way from the plant residue inputs
* similar structural units to the biomolecules,
* similar functional groups but not readily hydrolysed or oxidised.
* not clearly structurally defined (nor properties). Depend on inputs and location: there is no one “resistant SOM”.
•Main contributor to many SOM properties:
CEC (150 - 300 meq/100g), complexing capacity, soil pH,
water retention (~ 80% of its own weight), colour (brown/black).
A suggested structure.
Clay particle
Carbohydrate residue
Fe(OH)3
coating
Protein residue
Lignin residue
Acidic & phenolic functional groups
colour
colour
Has a high MW (>103), strongly adsorbed to particle surfaces, highly oxidised, extensively conjugated.
Sumber: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC238792/ ….. Diunduh 28/4/2012
The effect of temperature on the composting reaction of sewage
sludge was investigated at 50, 60, and 70°C.
The specific CO2 evolution rate (moles of CO2 evolved per hour per viable cell) was maximum at 70°C.
The isolated thermophilic bacterium which was dominant at 60°C but did not grow at 70°C showed that the rate of O2
consumption measured on the agar plate at 70°C was four times higher than that at 60°C.
This showed that the energy yielded from catabolism is rather uncoupled with the anabolism at 70°C in the metabolism of
microorganisms indigenous in the compost.
A higher respiratory quotient was observed at 70°C than at any other temperature.
. Appl Environ Microbiol. 1985 December; 50(6): 1526–1530. Effect of Temperature on Composting of Sewage SludgeKiyohiko Nakasaki, Makoto Shoda,* and Hiroshi Kubota
The total amount of CO2 evolved and the final
conversion of volatile matter were maximum at 60°C.,
suggesting that the optimal temperature for composting
was around 60°C.
KARAKTERISASI SUBSTANSI HUMIK
a) Isolation. Operationally defined by isolation procedure (cf lipids).
Soil1. HCl:
CO3- CO2
2. 0.5M NaOH
24 - 48 hrs, N2 atm,
10g soil/dm-3 caustic
3. Centrifuge
a: insoluble HUMINSoluble phase
1. 0.5M HCl 24hrs.
2. centrifuge
Soluble Fulvic Acid
Insoluble Humic Acid
* yellow/red solution* purify on a cation exchange resin
* dark red/brown solid* purify by - recrystallization (NaOH and HCl) - dialysis against water (removes cations)* speciate using MW cutoff dialysis.
** mole wt% mole% ratio C 54 4.5 1.7H 4 4 1.5O 42 2.6 1
N, S traces
** mole wt% mole% ratio C 55 4.6 2.1H 5 5 2.3O 35 2.2 1N 3 0.2 S 1 0.03 C21H23O10
** mole wt% mole% ratio C 45 3.8 1.4H 5 5 1.8O 45 2.8 1N 2 0.14 S 2 0.06 C13H18O10
C:H ~1:1 high degree of
unsaturation
* more O* more saturated
* unsaturated* high O but insoluble ether, but not acid or phenol groups.
** Elemental analyses (C, H,
N, S: O by difference) on an
ash free, dry weight basis
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/16018891 ….. Diunduh 28/4/2012
Sewage sludges are used in agriculture because they act as a fertilizer. Long-
term studies are needed to evaluate the effect of sewage sludge on soil properties by paying particular attention to the soil
organic matter.
At the end of the tests, compared to the control soil, the sludge-amended soil did not exhibit change in total organic C and
related humified fractions.
However, the HA composition of the soil treated with sludge had developed an HA composition closer to that of the HA-sludge as a result of the enrichment of recalcitrant fractions contained in
the sludge.
Chemosphere. 2005 Sep;60(9):1214-21. Epub 2005 Apr 1.Long-term effect of sewage sludge application on soil humic acids.
Adani F, Tambone F.
Soil plots were amended for 10 years with 1Mg dry matter ha(-1)year(-1) of sewage sludge. Chemical parameters such as total organic carbon (TOC), N,
C/N ratio and CEC were determined when this period ended. Moreover, TOC was
fractionated into humified and non-humified fractions. Humic acids (HA) were isolated and
studied by elemental analysis, DRIFT, (1)H NMR and CPMAS
13C NMR spectroscopies.
b) Acidity: The phenolic, R-OH and R-COOH functional groups give acidity but the many functional groups in many chemical environments prohibit the definition of an “acid dissociation constant” - many pKas but
they will be experimentally indistinguishable.
Therefore titrate with standard base over a defined pH range - operationally defined. FA ~ 5meq/g.
For HA dissolve in excess base and back titrate with standard acid.
KARAKTERISASI SUBSTANSI HUMIK
Al(OH)3 + OH- → Al(OH)4-
Gibbsite dissolution under Bayer conditions (3.5M NaOH, 140C)
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18338701 ….. Diunduh 28/4/2012
In order to carry out life-cycle assessments as a basis for far-reaching decisions about
environmentally sustainable waste treatment, it is important that the input data be reliable and sound. A comparison of the potential greenhouse gas (GHG)
emissions associated with each solid waste treatment option is essential.
The composition of source materials along with process management issues such as aeration, mechanical agitation, moisture control and temperature regime are the most
important factors controlling methane (CH4), nitrous oxide (N2O) and ammoniac (NH3) emissions. If ammoniac is not stripped during the initial rotting phase or eliminated by acid scrubber systems, biofiltration of waste air provides only limited GHG mitigation,
since additional N2O may be synthesized during the oxidation of NH3, and only a small amount of CH4 degradation occurs in the biofilter. It is estimated that composting
contributes very little to national GHG inventories generating only 0.01-0.06% of global emissions. This analysis does not include emissions from preceding or post-treatment
activities (such as collection, transport, energy consumption during processing and land spreading), so that for a full emissions account, emissions from these activities
would need to be added to an analysis.
Waste Manag Res. 2008 Feb;26(1):47-60.Green house gas emissions from composting and mechanical biological
treatment.Amlinger F, Peyr S, Cuhls C.
This paper addresses GHG emissions from controlled
composting processes. Some important methodological prerequisites for proper measurement and data
interpretation are described, and a common scale and dimension of emission data are proposed so that data from different studies
can be compared. A range of emission factors
associated with home composting, open windrow composting, encapsulated
composting systems with waste air treatment and mechanical
biological waste treatment (MBT) are presented from our own
investigations as well as from the literature.
Kingston Harbour sediment Fulvic Acid
Kingston Harbour sediment Humic
Acid
OH stretch
(C-H)aliphatic stretching
(C=O)acyl
stretching
(C-C)aromatic stretching
C-O stretching & C-OH bending
c) Vibrational spectroscopy
KARAKTERISASI SUBSTANSI HUMIK
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19157868 ….. Diunduh 28/4/2012
The intensification in livestock production has increased the need of efficient
treatments of waste streams especially to preserve as much as possible, the nutrients into the soil-plant system.
In this paper, an overview about the environmental and safety challenges of composting of manures is made considering the
compost quality requirements established by the main demanding sectors.
Co-composting and additive strategies are presented as feasible options for the improvement of compost quality.
For quality evaluation of manure compost, the use of both classical and innovative instrumental techniques could increase our
knowledge about added properties in compost, especially those related to organic matter stability.
Bioresour Technol. 2009 Nov;100(22):5454-60. Epub 2009 Jan 20.Utilisation of manure composts by high-value crops: safety and environmental
challenges.Moral R, Paredes C, Bustamante MA, Marhuenda-Egea F, Bernal MP.
Composting is a cheap, efficient and sustainable
treatment for solid wastes that is always included in any
manure treatment scenario.
d) NMR spectroscopy: (Solomons Chapter 14)
13C, solid state or NaOH solution.
* Broad band spectra (materials not homogeneous, solid state NMR have complicated orientational effects and lattice-nuclear spin
interactions). * Chemical shifts indicate functional
groups.* areas under peaks indicate relative amounts of functional
groups.
Ho = Happlied(1-) where is a shielding constant. The observed field at the nucleus is shifted from the applied field by magnetic properties of the shielding electrons. Quote the field at which resonance occurs relative to a standard (usually tetramethylsilane - TMS).
KARAKTERISASI SUBSTANSI HUMIK
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19119002 ….. Diunduh 28/4/2012
New livestock production systems, based on intensification in large farms, produce huge
amount of manures and slurries without enough agricultural land for their direct application as
fertilisers. Composting is increasingly considered a good way for recycling the surplus
of manure as a stabilised and sanitised end-product for agriculture, and much research
work has been carried out in the last decade. However, high quality compost should be
produced to overcome the cost of composting.
Special attention has been paid to the relevance of using an adequate bulking agent for reducing N-losses and the necessity
of standardising the maturity indices due to their great importance amongst compost quality criteria.
Bioresour Technol. 2009 Nov;100(22):5444-53. Epub 2008 Dec 31.Composting of animal manures and chemical criteria for compost maturity
assessment. A review.Bernal MP, Alburquerque JA, Moral R.
In order to provide and review the information found in the literature about manure composting, the first part of this paper explains the basic concepts of the composting process and how manure
characteristics can influence its performance. Then, a summary of those factors such as nitrogen losses
(which directly reduce the nutrient content), organic matter humification and compost maturity which
affect the quality of composts produced by manure
composting is presented.
“Kompos” merupakan hasil dekomposisi bahan organik yang dapat dipercepat secara artifisial oleh populasi mikroba dalam kondisi lingkungan
yang hangat, lembab, dan aerobik atau anaerobik.
“Pengomposan” adalah proses dimana bahan organik mengalami dekomposisi secara biologis, khususnya oleh mikroba-mikroba yang
memanfaatkan bahan organik tersebut sebagai sumber energy, sumber karbon dan sumber makanannya.
Kompos dapat diperkaya dengan unsur hara esensial makro dan mikro. Kompos ini dapat digunakan sebagai pupuk di kebun, taman,
tanaman hortikultura, dan tanaman pertanian lainnya.
Kompos sangat bermanfaat untuk memperbaiki kualitas tanah, dapat berfungsi sebagai pembenah tanah, sebagai pupuk, sumber humus
dan asam humat, atau sebagai pestisida alami bagi tanah.
Dalam ekosistem tanah, kompos bermanfaat untuk mengendalikan erosi, reklamasi lahan, dan lainnya.
KOMPOS DAN PENGOMPOSAN
“Membuat kompos” berarti mengatur dan mengontrol proses
dekomposisi bahan organic tersebut agar kompos dapat
terbentuk lebih cepat. Proses ini meliputi membuat
campuran bahan organic yang seimbang komposisinya,
pemberian air yang cukup, mengaturan aerasi, dan penambahan aktivator
pengomposan.
JENIS-JENIS KOMPOS1.Kompos cacing (vermicompost), yaitu kompos yang terbuat dari bahan organik yang dicerna oleh cacing. Bahan yang menjadi pupuk adalah kotoran cacing tersebut.2.Kompos bagase, yaitu pupuk yang terbuat dari ampas tebu sisa penggilingan tebu di pabrik gula.3.Kompos bokashi.4.KOMPOS
. Penggunaan kompos sangat baik karena dapat memberikan manfaat baik bagi tanah maupun tanaman. Kompos dapat menggemburkan tanah,
memperbaiki struktur dan porositas tanah, serta komposisi mikroorganisme tanah, meningkatkan daya ikat tanah terhadap air,
menyimpan air tanah lebih lama, dan mencegah lapisan kering pada tanah. Kompos juga menyediakan unsur hara mikro bagi tanaman,
memudahkan pertumbuhan akar tanaman, mencegah beberapa penyakit akar, dan dapat menghemat pemakaian pupuk kimia dan atau pupuk
buatan, sehingga dapat meningkatkan efisiensi pemakaian pupuk kimia.
KOMPOS DAN PENGOMPOSAN
Empat fungsi penting kompos, yaitu:1.Fungsi nutrisi, nutrisi yang disimpan diubah menjadi bahan organik, jaringan mikroorganisme, produk sisanya, dan humus. Kompos adalah pupuk yang lambat tersedia (slow release), hara yang dihasilkan tergantung pada bahan dasar dan metode pengomposan yang digunakan.2.Meningkatkan struktur tanah, yaitu melalui peningkatan persentase bahan organik yang meningkatkan stuktur tanah.3.Meningkatkan populasi dan aktivitas organisme tanah. Kompos juga meningkatkan kemampuan mengikat air dan agregat tanah, meningkatkan infiltrasi, menghalangi terjadinya erosi dan menunjang penyebaran dan penetrasi akar tanaman.4.Memperkuat daya tahan tanaman terhadap hama dan penyakit. Berbagai penelitian telah menunjukkan bahwa tanaman yang diberi pupuk kompos lebih tahan terhadap hama dibandingkan tanaman yang tidak diberi kompos maupun yang tidak dipupuk.
Manfaat Ekonomi :
1.Menghemat biaya untuk transportasi dan penimbunan limbah2.Mengurangi volume/ukuran limbah3.Memiliki nilai jual yang lebih tinggi dari pada bahan asalnya
Manfaat KOMPOS bagi tanah dan tanaman:1.Meningkatkan kesuburan tanah2.Memperbaiki struktur dan karakteristik tanah3.Meningkatkan kapasitas penyerapan air oleh tanah4.Meningkatkan aktivitas mikroba tanah5.Meningkatkan kualitas hasil panen (rasa, nilai gizi, dan jumlah panen)6.Menyediakan hormon dan vitamin bagi tanaman7.Menekan pertumbuhan/serangan penyakit tanaman8.Meningkatkan retensi/ketersediaan hara di dalam tanah
KOMPOS DAN PENGOMPOSAN
Mafaat Lingkungan :1.Mengurangi polusi udara karena pembakaran limbah dan pelepasan gas metana dari sampah organik yang membusuk akibat bakteri metanogen di tempat pembuangan sampah2.Mengurangi kebutuhan lahan untuk penimbunan sampah3. ……………
Sumber: http://www.microbiologyprocedure.com/organic-matter-decomposition/humus.html) ….. Diunduh 20/4/2012
Dekomposisi Bahan OrganikProses dekomposisi bahan organic menghasilkan beragam hasil, bauik yang
berupa hasil antara maupun hasil akhir. Hasil akhir dari proses ini disebut HUMUS, berwarna gelap dan stabil.
Humus dapat didefinisikan sebagai kompleks ligno-protein atau kompleks asam amino-lignin yang mengandung sekitar 45% senyawa lignin, 35% asam-
amino, 11% karbohydrates, 4% cellulose, 7% hemicellulose, 3% lemak, lilin dan resin; dan 6% senyawa lainnya termasuk zat pemicu pertumbuhan dan
inhibitors.
KOMPOS DAN PENGOMPOSAN
. Mikro-organisme dalam Pengomposan
Dengan pencampuran yang tepat antara air, oksigen, carbon, dan nitrogen, mikro-organisme dapat melakukan dekomposisi bahan organik menghasilkan KOMPOS. Ada banyak jenis mikroba yang aktif dalam kompos, yang paling
lazim adalah: 1.Bacteria- Jenis mikroba yang ditemukan dalam kompos.2.Actinomycetes- Diperlukan untuk menghancurkan produk-produk kertas, seperti newspaper, bark, dsb.3.Fungi- Molds dan yeast, membantu menghancurkan materisl yang tidak dapat dihancurkan oleh bakteri, seperti lignin dalam bahan-bahan berkayu.4.Protozoa- Membantu mengkonsumsi bakteri, fungi dan partikulat organik mikro.5.Rotifers- Rotifers membantu mengendalikan populasi bakteri dan small protozoans.
. Organisme pengomposan ini memerlukan empat imput penting secara simultan untuk dapat bekerja secara efektif:
1.Carbon — untuk energy; oksidasi mikrobiologis karbon menghasilkan panas.
Material kaya karbon cenderung coklat dan kering.2.Nitrogen — untuk menumbuhkan dan reproduksi organisme untuk mengoksidasi karbon.
Material kaya nitrogen cenderung hijau (seperti buah dan sayuran) dan basah.
3.Oxygen — untuk oksidasi karbon dan proses dekomposisi.4.Water — dalam jumlah yang tepat untuk mempertahankan aktivitas tanpa menimbulkan kondisi anaerobik.
KOMPOS DAN PENGOMPOSAN
Ratio yang tepat dari material-material di atas akan mensuplai bakteri dengan hara yang tepat sehingga ia dapat bekerja secara efektif dan akan memanaskan timbunan bahan organik dalam pengomposan.
Dalam proses ini akan dilepaskan banyak air sebgaai bentuk uap, dan oksigen akan cepat berkurang; sehingga timbunan bahan organik
harus sering diaduk-aduk. Semakin panas timbunan bahan organik, diperlukan penambahan
udara dan air yang semakin sering.; keseimbangan udara/air menjadi sangat penting untuk mempertahankan suhu tinggi hingga bahan
organik terdekomposisi.
Pada saat yang sama, terlalu banyak udara atau air juga dapat emenghambat proses dekomposisi, karena terlalu banyak carbon
(atau terlalu sedikit nitorgen).
Proses pengomposan paling efisien terjadi kalau bahan organik mempunyai ratio C/N = 30 / 1.
Semua biomasa tumbuhan dan hewan mengandung N dan C , tetapi jumlahnya sangat beragam, dengan karakteristik
yang berbeda-beda.
Biomasa legume segar mempunyai C/N ratio sekitar 15 : 1 dan daun-daun gugudran kering mempunyai C/N ratio
sekitar 50 : 1 tergantung spesiesnya.
Kalau kedua bahan ini dicampur akan dapat diperioleh kisaran C/N ratio yang ideal.
KOMPOS DAN PENGOMPOSAN
The most important function of soil microorganism is the decomposition of various kinds of organic matter present in the soil. Virtually all types of organic
matters eventually find their way to the soil or to the sea. The soil organic matter chiefly consists of residues of dead plant and animals, and the or to the
sea. The soil organic matter chiefly consists of residues of dead plant and animals, and the excretory products of the living beings.
These organic constituents need to be converted into simple inorganic forms (minerals) to make them available to the autotrophic organisms. This
conversion of organic matter into simple inorganic forms is called mineralization.
A conceptual model of nitrogen cycling in ornamental landscapes. Decomposing organic matter releases organic nitrogen that is mineralized
into forms available for plant and microbial uptake. Fertilization supplements the available nitrogen pool. Nitrogen acquired by microbial
biomass is immobilized and thus is unavailable for plant uptake. As microbes die and are themselves decomposed, nitrogen is returned to the
available pool. (Sumber: http://ohioline.osu.edu/sc186/sc186_14b.html)
MINERALISASI DAN HUMIFIKASI
Sumber: http:/ / www.studentsguide.in/microbiology/soil-microbiology/decomposition-of-organic-matter-soil-by-mineralization-and-humification.html
….. Diunduh 20/4/2012
Proses dekomposisi oksidatif mengubah bahan organic segar menjadi senyawa-senyawa anorganik yang lebih sederhana (proses mineralisasi) yang tersedia bagi pertumbuihan tanaman; dan residunya diubah menjadi humus sebagai hasil dari proses ‘humification’; proses mineralization dan
humification berlangsung secara sinergis-bersamaan.
Mineralisasi Bahan Organik oleh Mikroba , berakhir pada Humifikasi
. The mineralization is rendered mainly through decomposition of organic matter by soil microorganism, mainly fungi and bacteria. It is estimated that
90% of the mineralization of organic matter is the result of the metabolism of all other organisms, as well as the combustion of fuel and other materials.
. Proses dekomposisi bahan organic (segar) berlangsung cepat atau lambat tergantung padakomopisi kimiawi dari bahan organic tersebut. Proses dekomposisi bersifat kontinyu, tetapi berbagai komponen terdegradasi
dengan laju yang berbeda-beda.(sumber: http://wvlc.uwaterloo.ca/biology447/modules/module8/ soil/chap2d.htm).
DEKOMPOSISI BAHAN ORGANIK DALAM TANAH
Keseimbangan Hara - C/N Ratio
Nutrient balance is very much dependent on the type of feed materials being processed. Carbon provides the preliminary energy source and nitrogen
quantity determines the microbial population growth. Hence, maintaining the correct C:N ratio is important to obtain good quality compost. Bacteria,
actinomycetes, and fungi require carbon and nitrogen for growth. These microbes use 30 parts of carbon to 1 part of nitrogen.
Composting is usually successful when the mixture of organic materials consists of 20-40 parts of carbon to 1 part of nitrogen. However, as the ratio
exceeds 30, the rate of composting decreases. Further, as the ratio decreases below 25, excess nitrogen is converted to ammonia. This is released into the
atmosphere and results in undesirable odor
Organism yang mendekomposisi bahan organic menggunakan carbon sebagai sumber energi dan nitrogen untuk membangun struktur sel-
selnya. Mereka memerlukan lebih banyak C daripada N. Kalau terlalu banyak C, dekomposisi melambat ketika nitrogen sudah digunakan semua
dan sebagian organisms mati. Organisme lainnya membentuk material sel-selnya yang baru
menggunakan N simpanannya. Dalam prosesnya lebih banyak karbon dibakar. Sehingga jumlah karbon lebih banyak berkurang, sedangkan
nitrogen didaur-ulang. Akan tetapi proses dekomposisi berlangsung terus, ketika nilai C/N ratio masih lebih besar dari 30.
PROSES KIMIAWI DEKOMPOSISI BO
Proses dekomposisi bahan organic dipengaruhi oleh adanya C dan N. C:N ratio mencerminkan
proporsi relative dari kedua unur ini. Suatu material, misalnya, mempunyai karbon 25 kali
lebih banyak daripada nitrogen, maka disebut ia mempunyai C:N ratio sebesar 25:1, atau C:N
ratio 25.
Nilai C:N ratio 20, dimana C dan N merupakan jumlah yang tersedia, merupakan batas atas bagi kompos dimana tidak ada bahaya
perampokan nitrogen tanah.
Kalau banyak karbon berbentuk lignin atau material resisten lainnya, maka nilai actual C:N ratio lebih besar dari 20. Nilai C:N ratio menjadi factor kritis dalam pengomposan untuk mencegah
perampokan nitrogen tanah dan konservasi maximum-nitrogen dalam kompos.
C/N RATIO BAHAN ORGANIK
. Sumber: http: // whatcom.wsu.edu/ag/compost/fundamentals/ needs_carbon_nitrogen.htm
Hubungan antara C:N ratio bahan organic dengan laju mineralisasi N. (sumber: http://www.new.dpi.vic.gov.au/agriculture/farming-management/organic-
farming/organic-viticulture/soil-management)
PERUBAHAN RATIO C/N
During bio-conversion of the materials, concentration of carbon will be reduced while that of nitrogen will be increased, resulting in the reduction of
C:N ratio at the end of the composting process. The reduction can be attributed to the loss in total dry mass due to losses of C as CO2
Ammonium-N (NH4-N) and nitrate-N (NO3-N) will also undergo some changes. NH3 levels were increasing in the initial stages but declining
towards the end (Liao et al. 1995). In several instances, NO3 concentrations were less during the initial phases but gradually increased towards the end
and, in some instances, remained unchanged.
Maintaining NH3 concentration is important to avoid excess nitrogen losses and production of bad odor. Maintaining C:N ratio after composting is also
important to determine the value of finished compost as soil amendment for crops. The final C:N ratio of 15 to 20 will be expected and the value of more than 20 might have a negative impact and will damage the crop and seed
germination. The value of 10 has been suggested as ideal.
Levels of P along with N and K will be important to determine the quality of compost, as P is also one of the essential nutrients for
plant growth. A C:P ratio of 100 to 200 is desirable (Howe and Coker, 1992). Phosphorus is not lost by volatilization or lixiviation during the
composting process, but P concentration might increase as composting proceeds.
. Soil phosphorus forms and plant uptake. (Sumber: http://extension.missouri.edu/publications/DisplayPub.aspx?
P=G9180)
Fosfor (P)
Bentuk P dalam tanah yang tersedia bagi tanaman adalah anion orthophosphate. Untuk ketersediaan jangka panjang, senyawa organic Po
dapat dirombak untuk melepaskan orthophosphate. Senyawa-senyawa compounds ini berasal dari microorganisms dan limbah tanaman dan ternak, merupakan bagian dari materiak humik yang stabil dalam tanah. Agar supaya
P dari sumber organic ini dapat tersedia, ia perlu dihidrolisis dan di-mineralisasikan oleh mikroba, yang merupakan proses penting untuk
melepaskan ion orthophosphate yang tersedia bagi tanaman dan menjaga siklus P dalam ekosistem. Melalui proses mineralisasi, senyawa-senyawa Po
merupakan sumber P yang penting bagi tanaman dan mikroba tanah.
. Pelepasan fosfat dari senyawa P organic. (Sumber: http:// www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-27912006000200006&lng=en&nrm=iso&ignore=.htm)
MINERALISASI SENYAWA P ORGANIK
Sumber: http://id.wikipedia.org/wiki/Sulfur ….. Diunduh 20/4/2012
SULFUR (S) (BELERANG)
Adanya S dalam jumlah yang cukup banyak dapat memicu pembentukan senyawa volatile yang berbau menyengat.
Sumber utama S adalah dua asam aminio, yaitu cysteine dan methionine. Pada kondisi aerasi yang bagus, sulfides dioksidasi menjadi sulfates; tetapi pada kondisi anaerobic, mereka diubah menjadi sulfide organic yang volatuile atau menjadi H2S,
menimbulkan bau busuk. Beberapa senyawa seperti carbon disulfide, carbonyl sulfide, methyl mercaptum, diethyl sulfide, dimethyl sulfide, dan dimethyl disulfide
juga dapat menimbulkan bau busuk.
. (Sumber: http://www.scripps.edu/chem/wong/)
Belerang atau sulfur adalah unsur kimia dalam tabel periodik yang memiliki lambang S dan nomor atom 16.
Bentuknya adalah non-metal yang tak berasa. Belerang, dalam bentuk aslinya, adalah sebuah zat padat kristalin kuning. Di alam, belerang dapat ditemukan sebagai unsur murni atau sebagai mineral- mineral sulfide dan
sulfate. Ia adalah unsur penting untuk kehidupan dan ditemukan dalam dua asam amino.
Penggunaan komersilnya terutama dalam fertilizer namun juga dalam bubuk mesiu, korek api, insektisida dan fungisida.
Temperature and moisture may influence the size and composition of the mineralizable fraction, which in itself is not yet well defined. If advances are to
be made in understanding organic S turnover, improvements in characterization of organic S are vital. The separation of organic S into the two large, chemically 'fuzzy' pools of organic sulphate and carbon-bonded S is no longer sufficient for interpretation of the sophisticated incubation and tracer experiments now utilized. Attempts must be made to distinguish analytically the organic S pools of definite chemical and biological function. The recent
development of the 'microbial biomass S pool' is a good step in this direction.
. Mineralisasi belerang – sulfat secara kumulatif darui bahan organic jerami wheat-fallow dan perennial forage (alfalfa), menyatakan pelepasan S dan
perubahan fraksi dapat-lapuk yang diprediksi dengan model kinetik. (Sumber: http://www.icsu-scope.org/downloadpubs/scope48/chapter10.html)
DEKOMPOSISI BO: EFEK SUHU DAN KELEMBABAN
Sumber: ….. Diunduh 20/4/2012
Kadar Air
Moisture in compost comes from either the initial feedstock or the metabolic water produced by microbial action (0.6-0.8 g/g), but, during aerobic
composting, 1 g of organic matter releases about 25 kJ of heat energy, which is enough to vaporize 10.2 g of water (Finstein et al. 1986). This will be further
coupled with losses due to aeration (Naylor 1996), resulting in water loss during composting. Hence, moisture is an important factor to be controlled
during composting as it influences the structural and thermal properties of the material, as well as the rate of biodegradation and metabolic process of the
microbes.The moisture content of compost should be 60% after organic wastes have been mixed. Depending on the components of the mixture, initial moisture
content can range from 55%-70%. However, if this exceeds 60%, the structural strength of the compost deteriorates, oxygen movement is inhibited,
and the process tends to be anaerobic. Low C:N ratio materials (e.g., meat wastes) putrefy when anaerobic, while high ratio materials ferment. Both these
processes produce odor, leach nutrients, increase pathogens, and block air passages in the pile, hence they must be avoided.
As the moisture content decreases below 50%, the rate of decomposition decreases rapidly. Excessive moisture in the compost will prevent O2
diffusion to the organisms. Reduction in the moisture content below 30%-35% must be avoided since it causes a marked reduction in the
microbiological activity.
Moisture can be controlled either directly by adding water or indirectly by changing the operating temperature or the aeration regime. Feedstock with different moisture-holding capacities can be blended to achieve an
ideal moisture content.
PROSES FISIKA DALAM PENGKOMPOSAN
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
Oksigen dan AerasiAeration is a key element in composting, especially in aerobic composting, as a large amount of oxygen is consumed during initial stages. Aeration provides oxygen to the aerobic organisms necessary for composting. Proper aeration is needed to control the environment required for biological processes to thrive
with optimum efficiency. Oxygen is not only necessary for aerobic metabolism of microorganisms, but also for oxidizing various organic molecules present in the composting mass.
It also has the important function of controlling temperature as well as of removing excess moisture and gases.
If the oxygen supply is limited, the composting process might turn anaerobic, which is a much slower and odorous process. A minimum oxygen
concentration of 5% is necessary to avoid an anaerobic situation. Turning the pile regularly or by mechanical agitation will ensure sufficient oxygen supply.
.Aerasi Pada Pengomposan
Pengomposan yang cepat dapat terjadi dalam kondisi yang cukup
oksigen(aerob). Aerasi secara alami akan terjadi pada saat terjadi
peningkatan suhu yang menyebabkan udara hangat keluar dan udara yang
lebih dingin masuk ke dalam tumpukan kompos.
Aerasi ditentukan oleh porositas dan kandungan air bahan(kelembapan).
Apabila aerasi terhambat, maka akan terjadi proses anaerob yang akan
menghasilkan bau yang tidak sedap.
Aerasi dapat ditingkatkan dengan melakukan pembalikan atau
mengalirkan udara di dalam tumpukan kompos.
PROSES FISIKA DALAM PENGKOMPOSAN
Skema Proses Pengomposan Aerobik
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage ….. Diunduh 26/4/2012
Ukuran Partikel Bahan KomposDecomposition and microbial activity will be rapid near the surfaces as oxygen diffusion is very high. Small particles have more surface area and can degrade more quickly. Haug (1993) suggested that, for particles larger than 1 mm, oxygen diffusion would limit in the central part of the particles, thus the interior parts of the larger particles will be anaerobic
with a slower rate of decomposition. Particle size also affects moisture retention as well as free air space and porosity of the compost mixture.
Smaller particle size results in reduced air space and less porosity. Aerobic decomposition increases with smaller particle size; however, smaller particle size reduces the effectiveness
of the oxygen supply. By turning regularly, this problem can be solved.
The preferable size is 3 mm - 50 mm diameter. Compaction can also influence the free air space. By employing grinding and sieving
equipment, such problems can be avoided. At the end of the process, the bulk density of the compost would be expected to increase due to breakdown in the particle size of the material, resulting in more compact compost. But in some composting systems, where
water evaporation and water loss are high, the bulk density might decrease as the materials will be dried during the composting period.
Pile size and porosity of the materialThe size of the pile is of great significance and finds mention in the
sections on passive composting of manure piles and turned wind-rows . Where the pile or wind-row is too large, anaerobic zones occur near its
centre, which slows the process in these zones. On the other hand, piles or wind-rows that are too small lose heat quickly and may not achieve a temperature high enough to evaporate moisture and kill pathogens and
weed seeds. The optimal size of the piles and wind-rows should also consider such parameters as the physical property (porosity) of the materials and the way of forming the pile. While more porous materials allow bigger piles, heavy weights should not be put on top and materials should be kept as
loose as possible. Climate is also a factor. With a view to minimizing heat loss, larger piles are suitable for cold weather. However, in a
warmer climate, the same piles may overheat and in some extreme cases (75 °C and above) catch fire.
PROSES FISIKA DALAM PENGKOMPOSAN
Pathogens selama Pengomposan
In addition to the already discussed microbes, there will be many human, animal, and plant pathogens. It is not only the heat of the compost that destroys all these pathogens; it is a combination of factors including:
1.competition for food from compost microorganisms;2.inhibition and antagonism by compost microorganisms;3.consumption by compost microorganisms;4.biological heat generated by compost microorganisms; and5.antibiotics produced by compost microorganisms.
There is no doubt that the heat produced by thermophilic bacteria kills pathogenic microorganisms, viruses, bacteria,
protozoa, worms, and eggs that may inhabit humans.
A temperature of 50°C (122°F), if maintained for 24 h, is sufficient to kill all the pathogens, according to some sources. A
lower temperature will take longer to kill the pathogens.
A temperature of 46°C (115°F) may take nearly a week to kill the pathogens completely; a higher temperature may take only minutes. What we have yet to determine is how low those
temperatures can be and still achieve satisfactory pathogen elimination.
PROSES BIOLOGIS DALAM PENGKOMPOSAN
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage ….. Diunduh 20/4/2012
. The microbial biodiversity of compost is also important because it aids in the breakdown of the organic material. For example, in high-temperature compost
(80°C), only about 10% of sewage sludge solids could be decomposed in three weeks, whereas at 50°-60°C, 40% of the sludge solids were
decomposed in only seven days. The lower temperatures apparently allowed for a richer diversity of living things, which, in turn, had a greater effect on the
degradation of the organic matter.Even if every speck of the composting material is not subjected to the high
internal temperatures of the compost pile, the process of thermophilic composting nevertheless contributes immensely to the creation of a sanitary organic material. Or, in the words of one group of composting professionals:
"The high temperatures achieved during composting, assisted by the competition and antagonism among the microorganisms (i.e., biodiversity),
considerably reduce the number of plant and animal pathogens. While some resistant pathogenic organisms may survive and others may persist in cooler
sections of the pile, the disease risk is, nevertheless, greatly reduced."
TemperatureThe process of composting involves two temperature ranges: mesophilic
and thermophilic.
While the ideal temperature for the initial composting stage is 20-45 °C, at subsequent stages with the thermophilic organisms taking over, a
temperature range of 50-70 °C may be ideal.
High temperatures characterize the aerobic composting process and serve as signs of vigorous microbial activities.
Pathogens are normally destroyed at 55 °C and above, while the critical point for elimination of weed seeds is 62 °C. Turnings and aeration can
be used to regulate temperature.
PROSES BIOLOGIS DALAM PENGKOMPOSAN
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. During composting, around 50% of the organic matter will be fully mineralized, producing CO2 and water. Protein, cellulose, and hemicelluloses are easily degradable. Many of these compounds produce organic residues,
referred to as humic matter. A great deal of work has been recently conducted on humic matter from various sources. The amount of humic acid increases during the process. Increase in aromatic structures, phenolic structures, and
carboxylic structures was also evidenced, whereas decrease in O-alkyl structures, polysaccharides, and amino acids was recorded with no changes in
alkyl structures and carbohydrates (Chefetz et al. 1998).
. Senyawa Intermediate (antara) yang bersifat Toksik
Many phytotoxic chemicals will also be produced during composting that might significantly impact on germination, plant growth, and also
plant pathogens.
In many instances, composting can also be a source of zenobiotic and hazardous volatile organic compounds. Recently, more than 20
different types of volatile organic compounds and their intermediates were recovered from the municipal solid waste composting facility
(Komilis et al. 2004).
The major phytotoxic compounds include either phenolic compounds or short chain fatty acids (Young and Chou 2003).
Some of the phenolics are vanillic, trans-p-coumaric, cis-p-coumaric, p-hydroxybenzoic, ferulic, and o-hydroxyphenylacetic acids; short chain
fatty acids include acetic acid, propionic acid, and butyric acid. The amount of these compounds varies with the composting method and
feedstock.
PERUBAHAN KIMIAWI DALAM PENGKOMPOSAN
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. Kontrol Proses
Composting, being a microbial process, can be proceeded with a desired efficiency when the environmental requirements for decomposition are met at their optimal levels. To attain this, it is necessary to control the treat process.
The important control parameters such as pH, humidity, and C:N ratio can serve as indicators for expected process failure.
It is necessary to monitor the pH and maintain it between 6 and 7.5, which is an optimum range. It is well understood that during the process, this
parameter undergoes considerable change from an initial pH of 5-6 due to the formation of carbon dioxide and organic acids.
As the process progresses, the value will rise to 8-8.5, which is due to the decomposition of proteins and elimination of carbon dioxide.
In a practical operation, very little evidence exists that pH should be artificially adjusted.
The microorganisms that produce the acids can also utilize them as food after higher oxygen concentrations are established.
This typically occurs within a few days after the most readily biodegradable substances have been destroyed. The net effect is that
the pH begins to rise after a few days. The rise continues until a level of 7.5-9.0 is reached, and the mass
becomes alkaline. Attempts to control pH with sulphur compounds are often difficult to justify because of the cost involved.
PERUBAHAN KIMIAWI DALAM PENGKOMPOSAN
Sumber: ….. Diunduh 20/4/2012
Kontrol Proses
As discussed earlier, the temperature change during the process has a profound influence on the efficiency of the process. As microorganisms
decompose (oxidize) organic matter, heat is generated and the temperature of the compost is raised a few degrees as a result. The temperature is increased
to 60o-65oC in the second phase and the thermophilic digestion takes over.
Thermophilic treatment has advantage because of the increased organic removal efficiency, improved solid-liquid separation, and destruction of
pathogens. Above 60oC, the thermophilic fungus flora dies while continuing the actinomycetes' activities. The process stops when readily biodegradable
material is fully consumed.
The temperature then gradually decreases, which activates the reinvasion of the thermophilic fungus flora, which attacks the cellulose materials. On the
completion of the digestion, the temperature returns to the ambient.
The increase in the temperature favors saprophytic activities that cause the transformation of the material in composting.
Most composting should include temperature in the thermophilic range.
At these temperatures, the rate of organic matter decomposition is maximum, and weed seeds and most pathogenic microbes cannot survive. It is also very important to mix the composting substances so as to ensure that all parts are exposed to high
temperatures.
PERUBAHAN KIMIAWI DALAM PENGKOMPOSAN
Sumber: http://en.wikipedia.org/wiki/Mineralization_%28biology%29….. Diunduh 20/4/2012
MineralisasiThe end products of any composting process are water, organic and inorganic matter that can be used as soil amendment to supply essential nutrients to the
plants, in addition to the buffering action and to increase water-holding capacity.
During the composting process, the ash or inorganic component increases due to the loss of organic fraction or volatile solids as CO2. Values of volatile solids present in feedstock are between 65% and 99%. About one-third (20%)
of the organic material is decomposed into water and CO2, but this will be dependent on the feedstock, influenced by aeration, temperature control, and
nutrient levels.
In biology, mineralization refers to the process where an organic substance is converted to an inorganic substance. This may also be a normal biological
process which takes place during the life of an organism such as the formation of bone tissue or egg shells, largely with calcium.
PERUBAHAN KIMIAWI DALAM PENGKOMPOSAN
Mineralization in soil science is when the chemical compounds in organic matter decompose or are oxidized into plant-accessible
forms. Mineralization is the opposite of immobilization.
Chemical decomposition, analysis or breakdown is the separation of a chemical compound into elements or simpler compounds. It is sometimes defined as the exact
opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction. The stability that a chemical compound ordinarily has is eventually limited when
exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. Chemical decomposition is
exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis.
A broader definition of the term decomposition also includes the breakdown of one phase into two or more phases.
There are three broad types of decomposition reactions: thermal, electrolytic and catalytic(SUMBER: http://en.wikipedia.org/wiki/Chemical_decomposition)
Sumber: http://en.wikipedia.org/wiki/Chemical_decomposition….. Diunduh 22/4/2012
Formula Reaksi Kimia
Reaksi umum untuk dekomposisi kimiawi adalah:AB → A + B
Contoh yang spesifik adalah elektrolisis air menjadi gas hidrogen dan gas oksigen :
2 H2O(I) → 2 H2 + O2
An example of spontaneous decomposition is that of hydrogen peroxide, which will slowly decompose into water and oxygen:
2 H2O2 → 2 H2O + O2
Carbonates will decompose when heated, a notable exception being that of carbonic acid, H2CO3.
Carbonic acid, the "fizz" in sodas, pop cans and other carbonated beverages, will decompose over time (spontaneously) into carbon dioxide and water
H2CO3 → H2O + CO2
Other carbonates will decompose when heated producing the corresponding metal oxide and carbon dioxide. In the following equation M represents a
metal:MCO3 → MO + CO2
A specific example of this involving calcium carbonate:CaCO3 → CaO + CO2
Metal chlorates also decompose when heated. A metal chloride and oxygen gas are the products.
2 MClO3 → 2 MCl + 3 O2
A common decomposition of a chlorate to evolve oxygen utilizes potassium chlorate as follows:
2 KClO3 → 2 KCl + 3 O2
DEKOMPOSISI KIMIAWI
Sumber: http://en.wikipedia.org/wiki/Thermal_decomposition….. Diunduh 22/4/2012
Thermal decomposition, or thermolysis, is a chemical decomposition caused by heat. The decomposition temperature of a substance is the
temperature at which the substance chemically decomposes.The reaction is usually endothermic as heat is required to break chemical
bonds in the compound undergoing decomposition. If decomposition is sufficiently exothermic, a positive feedback loop is created producing thermal
runaway and possibly an explosion.
Contoh-contohCalcium carbonate (Limestone or chalk) decomposes into calcium oxide and
carbon dioxide when heated:CaCO3 → CaO + CO2
The reaction is used to make quick lime, which when hydrated becomes slaked lime and is used a building material.
Many oxides decompose at high enough temperatures, an example being the decomposition of mercuric oxide to give oxygen and mercury. The reaction
was used by Joseph Priestley to make the gas for the first time.
Some foods will decompose exothermically at cooking temperatures; anyone who has overheated sugar or syrupy foods will know how long they take to cool. Mild versions of the process will produce caramelised dishes that are
pleasant, but cannot be tasted safely before they have cooled to a comfortable temperature. Once they start to char, such dishes commonly will
continue in a positive feedback loop; they become dangerously hot and continue to blacken from the inside out, and smoke even well after being removed from the heat. In films, where stuntmen have to jump through
breaking windows, the window panes are often made of sugar, which is safer than glass.
Water, when heated to well over 2000 °C, decomposes to its constituent elements:
2 H2O → 2 H2 + O2 The compound with the highest known decomposition temperature is carbon monoxide at ≈3870 °C (≈7000 °F).
DEKOMPOSISI THERMAL
Sumber: http://en.wikipedia.org/wiki/Decomposition….. Diunduh 22/4/2012
DEKOMPOSISI BIOLOGIS = BIODEGRADASI
Decomposition (or rotting) is the process by which organic material is broken down into simpler forms of matter. The process is essential for
recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death. Although no two
organisms decompose in the same way, they all undergo the same sequential stages of decomposition.
The science which studies decomposition is generally referred to as taphonomy from the Greek word taphos, meaning tomb.
One can differentiate abiotic from biotic decomposition (biodegradation). The former means "degradation of a substance by chemical or physical
processes, eg hydrolysis). The latter one means "the metabolic breakdown of materials into simpler components by living organisms“, typically by
microorganisms.
DEKOMPOSISI BIOMASA TUMBUHANDecomposition of plant matter occurs in many stages. It begins with leaching by water; the
most easily lost and soluble carbon compounds are liberated in this process. Another early process is physical breakup or fragmentation of the plant material into smaller bits which have greater surface area for microbial colonization and attack. In smaller dead
plants, this process is largely carried out by the soil invertebrate fauna, whereas in the larger plants, primarily parasitic life-forms such as insects and fungi play a major breakdown role and are not assisted by numerous detritivore species. Following this, the plant detritus (consisting of cellulose, hemicellulose, microbial products, and lignin) undergoes chemical
alteration by microbes.
Different types of compounds decompose at different rates. This is dependent on their chemical structure. For instance, lignin is a component of wood, which is relatively resistant to decomposition and can in fact only be decomposed by certain fungi, such as the black-rot fungi. Said fungi are thought to be seeking the nitrogen content of lignin rather than its
carbon content. Lignin is one such remaining product of decomposing plants with a very complex chemical structure causing the rate of microbial breakdown to slow. Warmth determines the speed of
plant decay, with the rate of decay increasing as heat increases, i.e. a plant in a warm environment will decay over a shorter period of time.
In most grassland ecosystems, natural damage from fire, insects that feed on decaying matter, termites, grazing mammals, and the physical movement of animals through the
grass are the primary agents of breakdown and nutrient cycling, while bacteria and fungi play the main roles in further decomposition.
Sumber: http://en.wikipedia.org/wiki/Decomposition….. Diunduh 22/4/2012
A dead body that has been exposed to the open elements, such as water and air, will decompose more quickly and attract much more insect activity than a body that is buried or confined in special protective gear or artifacts. This is due, in part, to the limited number of insects that can penetrate a coffin and
the lower temperatures under soil.The rate and manner of decomposition in an animal body is strongly affected by a number of factors. In roughly descending degrees of importance, they
are:1.Temperature;2.The availability of oxygen;3.Prior embalming;4.Cause of death;5.Burial, depth of burial, and soil type;6.Access by scavengers;7.Trauma, including wounds and crushing blows;8.Humidity, or wetness;9.Rainfall;10.Body size and weight;11.Clothing;12.The surface on which the body rests;13.Foods/objects inside the specimen's digestive tract (bacon compared to lettuce).
The speed at which decomposition occurs varies greatly. Factors such as temperature, humidity, and the season of death all determine how fast a fresh
body will skeletonize or mummify.
A basic guide for the effect of environment on decomposition is given as Casper's Law (or Ratio): if all other factors are equal, then, when there is free access of air a body decomposes twice as fast than if immersed in water and
eight times faster than if buried in earth. Ultimately, the rate of bacterial decomposition acting on the tissue will be depend upon the temperature of the surroundings. Colder temperatures decrease the rate of decomposition
while warmer temperatures increase it.
FAKTOR DEKOMPOSISI BIOLOGIS
Sumber: http://en.wikipedia.org/wiki/Microbiology_of_decomposition ….. Diunduh 20/4/2012
Laju Respirasi (Penyerapan O2 dan Pembentukan CO2)
To ensure sufficient aeration in the compost pile, levels of oxygen consumption and carbon dioxide formation should be monitored regularly during the entire process. A 1:1 ratio (oxygen/ carbon dioxide) will be an
indication of a good composting process. Usually during the process, the oxygen concentration will reflect the changes in the CO2 evolution and temperature curves. The oxygen will decrease from
its initial value of 21% to a value of 10% over the first few days as the temperature increases and the CO2 evolution increases, but gradually the
oxygen level increases and returns to the 21% level as the temperature reaches ambient.
The relation between CO2 evolution and oxygen consumption is called respiratory quotient (RQ). The RQ value of a good composting process will be
about 0.9 (Atkinson et al. 1996).
Microbiology of decomposition is the study of all microorganisms (mainly bacteria and fungi) involved in the chemical and physical
processes during which organic matter is broken down and reduced to its original elements.
Decomposition microbiology can be divided between two fields of interest:
1.decomposition of plant materials;2.decomposition of cadavers and carcasses.
The decomposition of plant materials is commonly studied in order to understand the cycling of carbon within a given environment and to understand the subsequent impacts on soil quality. Plant material
decomposition is also often referred to as composting.
The decomposition of cadavers and carcasses has become an important field of study within forensic taphonomy.
PERUBAHAN KIMIAWI DALAM PENGKOMPOSAN
Sumber: http://en.wikipedia.org/wiki/Microbiology_of_decomposition….. Diunduh 24/4/2012
The breakdown of vegetation is highly dependent on oxygen and moisture levels. During decomposition, microorganisms require oxygen for their
respiration. If anaerobic conditions dominate the decomposition environment, microbial
activity will be slow and thus decomposition will be slow. Appropriate moisture levels are required for microorganisms to proliferate and to actively
decompose organic matter. In arid environments, bacteria and fungi dry out and are unable to take part in
decomposition. In wet environments, anaerobic conditions will develop and decomposition can also be considerably slowed down.
Decomposing microorganisms also require the appropriate plant substrates in order to achieve good levels of decomposition. This usually translates to
having appropriate carbon to nitrogen ratios (C:N). The ideal composting carbon-to-nitrogen ratio is thought to be approximately
30:1. As in any microbial process, the decomposition of plant litter by microorganisms will also be dependent on temperature. For example, leaves
on the ground will not undergo decomposition during the winter months where snow cover occurs as temperatures are too low to sustain microbial activities
NutrientsMicro-organisms require C, N, phosphorus (P) and potassium (K) as the
primary nutrients. Of particular importance is the C:N ratio of raw materials. The optimal C:N ratio of raw materials is between 25:1 and
30:1 although ratios between 20:1 and 40:1 are also acceptable. Where the ratio is higher than 40:1, the growth of micro-organisms is limited,
resulting in a longer composting time. A C:N ratio of less than 20:1 leads to underutilization of N and the excess may be lost to the atmosphere as ammonia or nitrous oxide, and odour can be a problem. The C:N ratio of
the final product should be between about 10:1 and 15:1.
Diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage
DEKOMPOSISI MIKROBIOLOGIS BIOMASA TUMBUHAN
Sumber: http://en.wikipedia.org/wiki/Aerobic_metabolism….. Diunduh 24/4/2012
Aerobic respiration requires oxygen in order to generate energy (ATP). Although carbohydrates, fats, and proteins can all be processed and
consumed as reactant, it is the preferred method of pyruvate breakdown in glycolysis and requires that pyruvate enter the mitochondrion in order to be
fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP (adenosine triphosphate), by substrate-level phosphorylation,
NADH and FADH2
Simplified reaction: C6H12O6 (aq) + 6 O2 (g) → 6 CO2 (g) + 6 H2O (l)
ΔG = -2880 kJ per mole of C6H12O6
The negative ΔG indicates that the reaction can occur spontaneously.The reducing potential of NADH and FADH2 is converted to more ATP through
an electron transport chain with oxygen as the "terminal electron acceptor". Most of the ATP produced by aerobic cellular respiration is made by oxidative
phosphorylation. This works by the energy released in the consumption of pyruvate being used to create a chemiosmotic potential by pumping protons
across a membrane.
This potential is then used to drive ATP synthase and produce ATP from ADP and a phosphate group. Biology textbooks often state that 38 ATP molecules can be made per oxidised glucose molecule during cellular respiration (2 from
glycolysis, 2 from the Krebs cycle, and about 34 from the electron transport system). However, this maximum yield is never quite reached due to losses (leaky membranes) as well as the cost of moving pyruvate and ADP into the mitochondrial matrix and current estimates range around 29 to 30 ATP per
glucose.
Aerobic metabolism is up to 15 times more efficient than anaerobic metabolism (which yields 2 mol ATP per 1 mol glucose). They share the initial pathway of glycolysis but aerobic metabolism continues with the Krebs cycle and oxidative phosphorylation. The post glycolytic reactions take place in the
mitochondria in eukaryotic cells, and in the cytoplasm in prokaryotic cells.
RESPIRASI AEROBIK
Sumber: http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic
reactions that involve the redox reaction (oxidation of one molecule and the reduction of another). Respiration is one of the key ways a cell gains useful energy to fuel cellular activity.
Nutrients that are commonly used by animal and plant cells in respiration include sugar, amino acids and fatty acids, and a common oxidizing agent (electron acceptor) is molecular oxygen (O2). Bacteria and archaea can also be lithotrophs and these organisms may respire using a broad range of inorganic molecules as electron donors and acceptors, such as sulfur, metal
ions, methane or hydrogen. Organisms that use oxygen as a final electron acceptor in respiration are described as aerobic, while those that do not are referred to as anaerobic.
The energy released in respiration is used to synthesize ATP to store this energy. The energy stored in ATP can then be used to drive processes requiring energy, including biosynthesis,
locomotion or transportation of molecules across cell membranes.
Cellular respiration in a typical eukaryotic cell.
RESPIRASI SELULER
Sumber: http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
Glycolysis is a metabolic pathway that takes place in the cytosol of cells in all living organisms. This pathway does not require oxygen, and can therefore
function under anaerobic conditions. The process converts one molecule of glucose into two molecules of pyruvate
(pyruvic acid), generating energy in the form of two net molecules of ATP. Four molecules of ATP per glucose are actually produced; however, two are
consumed as part of the preparatory phase. The initial phosphorylation of glucose is required to destabilize the molecule
for cleavage into two pyruvate. During the pay-off phase of glycolysis, four phosphate groups are transferred to ADP by substrate-level phosphorylation to make four ATP, and two NADH
are produced when the pyruvate are oxidized.
The overall reaction can be expressed this way:
Glucose + 2 NAD+ + 2 Pi + 2 ADP → 2 pyruvate + 2 NADH + 2 ATP + 2 H+ + 2 H2O+energy
PYRUVATE DECARBOXYLATION
Pyruvate is oxidized to acetyl-CoA and CO2 by the pyruvate dehydrogenase complex (PDC). The PDC contains multiple copies of three enzymes and is located in the mitochondria of eukaryotic cells and in the
cytosol of prokaryotes. In the conversion of pyruvate to acetyl-CoA, one molecule of NADH and
one molecule of CO2 is formed. This step is also known as the link reaction or transition step, as it links glycolysis and the Krebs cycle.
GLYCOLYSIS
This is also called the Krebs cycle or the tricarboxylic acid cycle. When oxygen is present, acetyl-CoA is produced from the pyruvate molecules created from
glycolysis. Once acetyl-CoA is formed, two processes can occur, aerobic or anaerobic respiration. When oxygen is present, the mitochondria will undergo aerobic
respiration which leads to the Krebs cycle. However, if oxygen is not present, fermentation of the pyruvate molecule will occur.
In the presence of oxygen, when acetyl-CoA is produced, the molecule then enters the citric acid cycle (Krebs cycle) inside the mitochondrial matrix, and gets oxidized to CO2 while at the same time reducing NAD to NADH. NADH can be used by the electron transport chain to create further ATP as part of
oxidative phosphorylation. To fully oxidize the equivalent of one glucose molecule, two acetyl-CoA must be metabolized by the Krebs cycle. Two
waste products, H2O and CO2, are created during this cycle.
The citric acid cycle is an 8-step process involving different enzymes and co-enzymes. Throughout the entire cycle, acetyl-CoA(2 carbons) +
Oxaloacetate(4 carbons). Citrate(6 carbons) is rearranged to a more reactive form called Isocitrate(6 carbons).
Isocitrate(6 carbons) modifies to become α-Ketoglutarate(5 carbons), Succinyl-CoA, Succinate, Fumarate, Malate, and finally, Oxaloacetate.
The net energy gain from one cycle is 3 NADH, 1 FADH2, and 1 GTP; the GTP may subsequently be used to produce ATP. Thus, the total energy yield from
one whole glucose molecule (2 pyruvate molecules) is 6 NADH, 2 FADH2, and 2 ATP.
SIKLUS ASAM SITRAT
Sumber: http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
In eukaryotes, oxidative phosphorylation occurs in the mitochondrial cristae. It comprises the electron transport chain that establishes a proton gradient
(chemiosmotic potential) across the inner membrane by oxidizing the NADH produced from the Krebs cycle.
ATP is synthesised by the ATP synthase enzyme when the chemiosmotic gradient is used to drive the phosphorylation of ADP. The electrons are finally transferred to exogenous oxygen and, with the addition of two protons, water
is formed.The table below describes the reactions involved when one glucose molecule
is fully oxidized into carbon dioxide. It is assumed that all the reduced coenzymes are oxidized by the electron transport chain and used for oxidative
phosphorylation.
FOSFORILASI OKSIDATIF
Sumber: http://en.wikipedia.org/wiki/Aerobic_metabolism ….. Diunduh 24/4/2012
Stepcoenzyme
yieldATP yield Source of ATP
Glycolysis preparatory phase
-2Phosphorylation of glucose and fructose
6-phosphate uses two ATP from the cytoplasm.
Glycolysis pay-off phase
4 Substrate-level phosphorylation
2 NADH 4–6
Oxidative phosphorylation – Each NADH produces net 3 ATP due to NADH transport over the mitochondrial
membraneOxidative
decarboxylation of pyruvate
2 NADH 6 Oxidative phosphorylation
Krebs cycle
2 Substrate-level phosphorylation
6 NADH 18 Oxidative phosphorylation
2 FADH2 4 Oxidative phosphorylation
Total yield 36–38 ATPFrom the complete oxidation of one
glucose molecule to carbon dioxide and oxidation of all the reduced coenzymes.
Anaerobic respiration is a form of respiration using electron acceptors other than oxygen. Although oxygen is not used as the final electron acceptor, the
process still uses a respiratory electron transport chain; it is respiration without oxygen.
In order for the electron transport chain to function, an exogenous final electron acceptor must be present to allow electrons to pass through the
system. In aerobic organisms, this final electron acceptor is oxygen. Molecular oxygen is a highly oxidizing agent and, therefore, is an excellent
acceptor. In anaerobes, other less-oxidizing substances such as sulfate (SO4
2-), nitrate (NO3
-), or sulfur (S) are used. These terminal electron acceptors have smaller reduction potentials than O2, meaning that less energy is released per oxidized
molecule. Anaerobic respiration is, therefore, in general energetically less efficient than aerobic respiration.
Anaerobic respiration is used mainly by prokaryotes that live in environments devoid of oxygen. Many anaerobic organisms are obligate anaerobes,
meaning that they can respire only using anaerobic compounds and will die in the presence of oxygen.
KEPENTINGAN EKOLOGISAnaerobic respiration plays a major role in the global nitrogen, sulfur, and carbon cycles through the reduction of the oxyanions of nitrogen, sulfur,
and carbon to more-reduced compounds. Dissimilatory denitrification is the main route by which biologically fixed
nitrogen is returned to the atmosphere as molecular nitrogen gas. Hydrogen sulfide, a product of sulfate respiration, is a potent neurotoxin
and responsible for the characteristic 'rotten egg' smell of brackish swamps. Along with volcanic hydrogen sulfide, biogenic sulfide has the capacity to precipitiate heavy metal ions from solution, leading to the
deposition of sulfidic metal ores.
RESPIRASI ANAEROBIK
Sumber: http://en.wikipedia.org/wiki/Anaerobic_respiration ….. Diunduh 24/4/2012
Sumber: http://en.wikipedia.org/wiki/Anaerobic_respiration ….. Diunduh 20/4/2012
TIPE-TIPE RESPIRASI
type lifestyle electron acceptor products Eo' [V] example organisms
aerobic respiration
obligate and facultative aerobes
oxygen O2 H2O + CO2 + 0.82 eukaryotes
[iron] reductionfacultative
aerobes, obligate anaerobes
ferric iron Fe(III) Fe(II) + 0.75
Geobacter, Geothermobacter, Geopsychrobacter,
Pelobacter carbinolicus, P. acetylenicus, P.
venetianus, Desulfuromonadales,
Desulfovibrio
manganese reduction
facultative or obligate
anaerobesMn(IV) Mn(II)
Desulfuromonadales, Desulfovibrio
cobalt reductionfacultative or
obligate anaerobes
Co(III) Co(II)Geobacter
sulfurreducens
uranium reductionfacultative or
obligate anaerobes
U(VI) U(IV)
Geobacter metallireducens,
Shewanella putrefaciens,
(Desulfovibrio)
nitrate reduction (denitrification)
facultative aerobes
nitrate NO3− nitrite NO2
– + 0.40Paracoccus denitrificans
, E. colifumarate respiration
facultative aerobes
fumarate succinate + 0.03 Escherichia coli
sulfate respirationobligate
anaerobessulfate SO4
2− sulfide HS− - 0.22Desulfobacter latus,
Desulfovibrio' oxygen
methanogenesis (carbonate reduction)
methanogenscarbon dioxide
CO2
methane CH4 - 0.25 Methanothrix thermophila
sulfur respiration (sulfur reduction)
facultative aerobes and
obligate anaerobes
sulfur S0 sulfide HS− - 0.27 Desulfuromonadales
acetogenesis (carbonate reduction)
acetogenscarbon dioxide
CO2acetate - 0.30 Acetobacterium woodii
TCA reductionfacultative or
obligate anaerobes
trichloroacetic acid
dichloroacetic acid
Trichlorobacter (Geobacteraceae)
Sumber: ….. Diunduh 20/4/2012
Penambahan Bulking Agents, Shredding the Substrates, dan Mixing
Generally, mixing of bulking agents such as woodchips, yard trimmings, bark, rice hulls, municipal solid wastes or previously composted materials is used to add a source of carbon, lower the moisture content, provide structural support,
increase porosity, and favor aeration. The composting method involves the use of substrates that are fairly coarsely shredded to obtain biomasses with interstitial spaces (homogeneous empty spaces) that account for more than 25% of the total volume of the biomass to be bio-oxidized. This is done in an attempt to overcome the problem, commonly encountered with agglomerated
biomasses, of anaerobic fermentation occurring during the bio-oxidation stage.
. The principal limitations of all composting systems currently in use are the following:
1.Poor, uneven aeration of the biomass;2.Fluctuation of the temperature of the biomass during the bio-oxidation stage;3.Unsuitability of the system to the use of mycelial microorganisms;4.Few active contacts between microorganisms/enzymes and substrate;5.Little, if any, protection of the enzymes/microorganisms from external agents;6.Limited use of the capacity of the bioreactors.
PERUBAHAN KIMIAWI DALAM PENGKOMPOSAN
The reasons for these limitations have been identified and studied, as follows:
1.The poor and uneven aeration of the biomass is due mainly to the fact that during the bio-oxidative process, the "structure" of the solid substrates loses its original characteristics. As a result, the substrates tend to collapse and fall in on themselves or, in the case of rigid substrates, tend to become compacted. Consequently, areas develop where the substrates become compacted, reducing and/or eliminating the interstitial spaces. The airflow is then reduced or blocked in these areas.2.The temperature fluctuations during the bio-oxidative stage are due to the moisture initially present in the biomass evaporating during turning (designed to break up the aggregated mass and aerate it at the same time) and to conductive and convective phenomena developing in the biomass.3.The unsuitability of the system to the use of mycelial microorganisms is due to the fact that the mycelium is damaged when the biomass is turned and so prevented from developing to the optimal degree on the surface of the substrate to be used and converted to useful biomass and/or to a particular product.4.The low number of active contacts between microorganisms/enzymes and substrate is due mainly to the limited surface area of the substrate.5.The lack of protection for the enzymes/microorganisms from external agents is due mainly to the virtually non-existent porosity of the solid substrates.6.The limited use of the capacity of the bioreactors is linked to the need to mix the biomass with bulking agents and/or to turn or stir the biomass.
FAKTOR DEKOMPOSISI BAHAN ORGANIK
Sumber: http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
Sumber: http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
Odor is the major problem associated with composting. Adopting proper management options can solve this problem.
Odor is usually produced because of anaerobic conditions. Sources of anaerobic odors include a wide range of compounds, mainly ammonia, hydrogen sulphide, dimethyl disulphide,
methanethiol, volatile fatty acids, amines, and several aromatic compounds.Odor usually originates from the site where it is stored and its storage condition prior to
composting. Once the ingredients are incorporated into the composting system, subsequent odor problems are associated with the anaerobic conditions. Hence, it will be very essential to
bring them back to aerobic conditions. The best way is to combine ingredients with coarse, dry bulking agents to increase porosity and to allow sufficient oxygen penetration. Subsequent turning and forced aeration systems
can also provide sufficient oxygen. In addition to these conventional systems, oxidizing chemicals like hydrogen peroxide, potassium permanganate, and chlorine can be used to
control the odor, but care should be taken not to kill the composting microorganisms. In situ biological oxidation or biofilteration is also an effective method of controlling the bad odors.
Commercial enzyme catalysts and different biofiltering units, which can effectively reduce the odors, are available in the market.
Methanogenesis or biomethanation is the formation of methane by microbes known as methanogens. Organisms capable of producing methane have been identified only from
the domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria. The production of
methane is an important and widespread form of microbial metabolism. In most environments, it is the final step in the decomposition of biomass.
Methanogenesis in microbes is a form of anaerobic respiration. Methanogens do not use oxygen to respire; in fact, oxygen inhibits the growth of methanogens. The terminal
electron acceptor in methanogenesis is not oxygen, but carbon. The carbon can occur in a small number of organic compounds, all with low molecular weights. The two best
described pathways involve the use of carbon dioxide and acetic acid as terminal electron acceptors:
CO2 + 4 H2 → CH4 + 2H2OCH3COOH → CH4 + CO2
However, methanogenesis has been shown to use carbon from other small organic compounds, such as formic acid (formate), methanol, methylamines, dimethyl sulfide, and
methanethiol.The biochemistry of methanogenesis is relatively complex, involving the following coenzymes and cofactors: F420, coenzyme B, coenzyme M, methanofuran, and
methanopterin.
PENANGANAN BAU DALAM PENGOMPOSAN
FAKTOR YANG MEMPENGARUHI PROSES PENGOMPOSAN
Setiap organisme pendegradasi bahan organik membutuhkan kondisi lingkungan dan bahan yang berbeda-beda.
Apabila kondisinya sesuai, maka dekomposer tersebut akan bekerja giat untuk mendekomposisi limbah padat organik.
Apabila kondisinya kurang sesuai atau tidak sesuai, maka organisme tersebut akan dorman, pindah ke tempat lain, atau bahkan mati. Menciptakan kondisi yang optimum untuk proses pengomposan sangat menentukan keberhasilan
proses pengomposan itu sendiri.
Rasio C/N Rasio C/N yang efektif untuk proses pengomposan berkisar antara 30: 1 hingga 40:1. Mikroba memecah senyawa C sebagai sumber energi dan menggunakan N untuk sintesis protein. Pada rasio C/N di antara 30 s/d
40 mikroba mendapatkan cukup C untuk energi dan N untuk sintesis protein.
Apabila rasio C/N terlalu tinggi, mikroba akan kekurangan N untuk sintesis protein sehingga dekomposisi berjalan lambat. Umumnya, masalah utama pengomposan adalah pada rasio C/N yang tinggi,
terutama jika bahan utamanya adalah bahan yang mengandung kadar kayu tinggi (sisa gergajian kayu, ranting, ampas tebu, dsb).
Untuk menurunkan rasio C/N diperlukan perlakuan khusus, misalnya menambahkan mikroorganisme selulotik (Toharisman, 1991) atau
dengan menambahkan kotoran hewan karena kotoran hewan mengandung banyak senyawa nitrogen.
FAKTOR-FAK TOR PENGOMPOSAN
Sumber: http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
Sumber: http://en.wikipedia.org/wiki/Compost….. Diunduh 20/4/2012
Ukuran Bahan KomposAktivitas mikroba berada diantara permukaan area dan udara. Permukaan
area yang lebih luas akan meningkatkan kontak antara mikroba dengan bahan dan proses dekomposisi akan berjalan lebih cepat.
Ukuran partikel juga menentukan besarnya ruang antar bahan (porositas). Untuk meningkatkan luas permukaan dapat dilakukan dengan memperkecil
ukuran partikel bahan tersebut.
MIKROBA PENGOMPOSANWith the proper mixture of water, oxygen, carbon, and nitrogen, micro-
organisms are allowed to break down organic matter to produce compost. The composting process is dependant on micro-organisms to break down organic matter into compost. There are many types of microorganisms found in active compost of which the most common
are:1.Bacteria- The most numerous of all the micro organisms found in compost.2.Actinomycetes- Necessary for breaking down paper products such as newspaper, bark, etc.3.Fungi- Molds and yeast help break down materials that bacteria cannot, especially lignin in woody material.4.Protozoa- Help consume bacteria, fungi and micro organic particulates.5.Rotifers- Rotifers help control populations of bacteria and small protozoans.
In addition, earthworms not only ingest partly composted material, but also continually re-create aeration and drainage tunnels as they move
through the compost.A lack of a healthy micro-organism community is the main reason why composting processes are slow in landfills with environmental factors
such as lack of oxygen, nutrients or water being the cause of the depleted biological community.
FAKTOR-FAK TOR PENGOMPOSAN
. Aerasi Pengomposan yang cepat dapat terjadi dalam kondisi yang cukup oksigen(aerob). Aerasi secara alami akan terjadi pada saat terjadi
peningkatan suhu yang menyebabkan udara hangat keluar dan udara yang lebih dingin masuk ke dalam tumpukan kompos. Aerasi ditentukan oleh
posiritas dan kandungan air bahan(kelembaban). Apabila aerasi terhambat, maka akan terjadi proses anaerob yang akan menghasilkan bau yang tidak
sedap. Aerasi dapat ditingkatkan dengan melakukan pembalikan atau mengalirkan udara di dalam tumpukan kompos.
Mengapa oksigen sangat penting?
There are any very important reasons to keep compost aerobic, with oxygen levels greater than 15%: When the oxygen is depleted ANaerobic bacteria
take over, and some of their byproducts are phytotoxic, toxic to plant growth, toxic to germinating seeds. Some of these intermediate microbial metabolites
are VFA's, Volatile Fatty Acids. Many of the byproducts of anaerobic decomposition are foul odors.
. Porositas Porositas adalah ruang diantara partikel di dalam tumpukan kompos.
Porositas dihitung dengan mengukur volume rongga dibagi dengan volume total. Rongga-rongga ini akan diisi oleh air dan udara. Udara akan
mensuplay Oksigen untuk proses pengomposan. Apabila rongga dijenuhi oleh air, maka pasokan oksigen akan berkurang dan proses pengomposan
juga akan terganggu.
FAKTOR-FAK TOR PENGOMPOSAN
Sumber: http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
Sumber: http://wmr.sagepub.com/content/12/4/289.abstract ….. Diunduh 20/4/2012
Kelembaban (Moisture content) Kelembaban memegang peranan yang sangat penting dalam proses metabolisme mikroba
dan secara tidak langsung berpengaruh pada suplay oksigen. Mikrooranisme dapat memanfaatkan bahan organik apabila bahan organik tersebut larut di dalam air.
Kelembaban 40 - 60 % adalah kisaran optimum untuk metabolisme mikroba. Apabila kelembaban di bawah 40%, aktivitas mikroba akan mengalami penurunan dan akan lebih rendah lagi pada kelembaban 15%. Apabila kelembaban lebih besar dari 60%, hara akan
tercuci, volume udara berkurang, akibatnya aktivitas mikroba akan menurun dan akan terjadi fermentasi anaerobik yang menimbulkan bau tidak sedap.
Characterization of Compost From a Pilot Plant-Scale Composter Utilizing Simulated Solid Waste
Burney S. Schwab, Carla J. Ritchie, D. James Kain, G. Chris Dobrin, Lawrence W. King, Anna C. Palmisano
Waste Manag Res July 1994 vol. 12 no. 4 289-303
A pilot plant-scale composter using simulated solid waste was developed to test the fate of consumer products such as disposable diapers.
The simulated waste consisted of a mixture of rabbit chow (which included alfalfa), shredded newspaper, sand, and composted cow manure.
The compost mass self-heated from an ambient temperature of 27°C to about 55°C in the first 24 h. Dissolved ammonia levels, high in the early stages of
the process, began to decrease after about 4 weeks as nitrate concentration began to increase. Both volatile solids and carbon:nitrogen ratios exhibited gradual decreases with time. Microbial biomass, esterase activity, cellulose
mineralization, direct microscopic counts (AODC), and relative APIZYM enzyme activity increased significantly in the first several days, and
maintained higher levels than initial measurements throughout the 22-week testing period.
We concluded that the simulated solid waste underwent physical, chemical, and microbiological changes that would be expected to occur in municipal solid waste in a full-scale composting system.
The pilot plant-scale composter should prove to be a valuable tool in assessing the fate of products and materials under simulated
compost conditions.
FAKTOR-FAK TOR PENGOMPOSAN
.. Temperatur/suhu Panas dihasilkan dari aktivitas mikroba. Ada hubungan langsung antara
peningkatan suhu dengan konsumsi oksigen. Semakin tinggi temperatur akan semakin banyak konsumsi oksigen dan akan semakin cepat pula proses
dekomposisi. Peningkatan suhu dapat terjadi dengan cepat pada tumpukan kompos. Temperatur yang berkisar antara 30 - 60oC menunjukkan aktivitas
pengomposan yang cepat. Suhu yang lebih tinggi dari 60oC akan membunuh sebagian mikroba dan hanya mikroba thermofilik saja yang akan tetap
bertahan hidup. Suhu yang tinggi juga akan membunuh mikroba-mikroba patogen tanaman dan benih-benih gulma.
. Typical Time-Temperature Relationship for Composting Organic Wastes by the Beltsville Aerated Pile Method. Curve 1 Indicates That Conditions of Moisture,
Temperature, C:N Ratio, and Aeration Are at Optimum Levels for Rapid Aerobic, Thermophilic Composting. within Several Days, the Internal Pile Temperatures Increase Rapidly from the Mesophilic (20 to 40°C) into the Thermophilic (> 40°C) Stage, after Which the Temperature Begins to Decline As Available Nutrients Are Depleted by the
Indigenous Microorganisms. Curve 2 Indicates What Might Happen When Certain Parameters Are Deficient or Outside Their Optimum Range, Which Would Limit the
Growth and Activity of Microorganisms and Adversely Affect the Desired Time-Temperature Transition for Successful Composting.Sumber:
http://www.agnet.org/library/eb/394/
FAKTOR-FAK TOR PENGOMPOSAN
Sumber: ….. Diunduh 20/4/2012
Kemasaman (pH )Proses pengomposan dapat terjadi pada kisaran pH yang lebar. pH yang optimum untuk
proses pengomposan berkisar antara 6.5 sampai 7.5. pH kotoran ternak umumnya berkisar antara 6.8 hingga 7.4. Proses pengomposan sendiri akan menyebabkan perubahan pada
bahan organik dan pH bahan itu sendiri. Sebagai contoh, proses pelepasan asam, secara temporer atau lokal, akan menyebabkan penurunan pH (pengasaman), sedangkan produksi amonia dari senyawa-senyawa yang mengandung nitrogen akan meningkatkan pH pada fase-fase awal pengomposan. pH
kompos yang sudah matang biasanya mendekati netral.
Variability of Temperature, pH, and Moisture in an Aerobic Composting Process (Steven H. Atchley and J. B. Clark. Appl Environ Microbiol. 1979
December; 38(6): 1040–1044. )
This study measured the environmental variability which exists in a commercial aerobic composting process. The specific process studied is carried out in six decomposition cells which present six different phases of the process. Temperature, pH, and moisture content
were determined in several randomly chosen sample sites in each cell, both at the beginning and at the end of the time the material was left in the cell. Temperature and pH varied greatly from one sample site to another in each cell, whereas moisture content was less varied. A significant rise in both temperature and pH was observed at two stages of
degradation.
FAKTOR-FAK TOR PENGOMPOSAN
Sumber: http://wmr.sagepub.com/content/11/2/117 ….. Diunduh 22/4/2012
Composting experiments of garbage were conducted by using a laboratory
scale reactor under well controlled experimental conditions and the effects
of pH control were quantitatively analysed.
The degradation rate of organic matter in the pH controlled experiment was faster than that without. Nitrogen loss was enhanced by the control of
pH value, but the amount of promotion was relatively small.
The pH dependency on the activity of microorganisms, which contribute to the composting rate, was investigated by using a liquid medium containing
glucose and proteins as nutrients.
The optimum pH for the growth rate and the degradation activity of proteins of the microorganisms was in the range of 7-8, while the decomposition of glucose proceeded rapidly at an early stage of
composting in a pH range from 6 to 9.
Effects of pH Control On Composting of GarbageKiyohiko Nakasaki, Hideki Yaguchi, Yasushi Sasaki, Hiroshi Kubota
Waste Manag Res March 1993 vol. 11 no. 2 117-125
In the pH controlled
experiment, lime was added to prevent pH
decreasing below 7,
especially at the early stage of composting.
Sumber: http://wmr.sagepub.com/content/12/2/165.abstract ….. Diunduh 25/4/2012
Kandungan Hara Kandungan P dan K juga penting dalam proses pengomposan dan bisanya terdapat di
dalam kompos-kompos dari peternakan. Hara ini akan dimanfaatkan oleh mikroba selama proses pengomposan.
Kandungan Bahan Berbahaya Beberapa bahan organik mungkin mengandung bahan-bahan yang berbahaya bagi
kehidupan mikroba. Logam-logam berat seperti Mg, Cu, Zn, Nickel, Cr adalah beberapa bahan yang termasuk kategori ini. Logam-logam berat akan mengalami imobilisasi selama
proses pengomposan.
. Poultry Waste Management for Crop Production: Nigerian Experience
G.O. Adeoye, M.K.C. Sridhar, O.E. MohammedWaste Manag Res March 1994 vol. 12 no. 2 165-172
Poultry wastes are posing serious environmental pollution problems in Nigeria through offensive odours and promotion of fly and rodent
breeding. Farmers normally dispose of their poultry wastes through heaping and
burning or dumping on the farm in the fresh state.
Experiments were conducted to stabilize the waste for 12 weeks by a bag process similar to static pile composting either singly or amended
with sawdust or leaves.
Sawdust seems to be ideal for the production of a well stabilized product which is environmentally safe. However, even the raw waste or leaf amended waste if kept for 8 to 12 weeks produced a product which
has no adverse effect on the maize yield when applied at 20 tonnes/hectare.
The soils were improved through organic matter and retention of plant nutrients.
FAKTOR-FAK TOR PENGOMPOSAN
Sumber: http://wmr.sagepub.com/content/12/1/3.abstract ….. Diunduh 22/4/2012
Water hyacinth grows ubiquitously in natural water bodies in the tropics. If allowed to propagate without control, it can cause deterioration of water quality and create
problems with water uses. However, water hyacinth has been used for wastewater
treatment, and as an animal feed and soil conditioner.
The water hyacinth plants mixed with molasses and pig manure at the ratios of 85:10:5 (% wet weight) were found to be optimum for silage
production; the silaging period was 28 days.
The silaged products contained 16% protein and 18% dry matter, suitable for use as animal feed. The composted water hyacinth plants, whose raw materials included pig manure and leaves, contained N, P and K about
2.2, 1.5, and 0.8% (dry weight), respectively.
An economic analysis of the two recycling options suggested that some benefits could be gained from these practices after 5 years of operation.
These two options were found to be technically and economically feasible to be implemented at farm scale levels.
PRODUCTION OF FEED AND FERTILIZER FROM WATER HYACINTH PLANTS IN THE TROPICS
C. Polprasert, N. Kongsricharoern, W. Kanjanaprapin
Waste Manag Res January 1994 vol. 12 no. 1 3-11
This paper reports a case study on silaging and
composting of water hyacinth plants generated from
ponds treating pig farm wastewater.
Sumber: http://wmr.sagepub.com/content/12/1/13.abstract ….. Diunduh 22/4/2012
. Grass clippings were composted with an autothermal packed bed type
laboratory-scale reactor in which a desired temperature (60°C) is
maintained by controlling air flow rate.
Time courses of CO2 evolution rate and conversion of carbon, corresponding to total amount of organic matter decomposed, differed
substantially among the experimental runs with controlled different moisture levels. The moisture level yielding the most rapid decomposition
of organic matter in the grass clippings was around 50% (W/W).
Analyses of HPLC pattern of water soluble organic matter and concentrations of organic matter constituents in the composting solid
also indicated that the composting rate could be accelerated by keeping the adequate moisture level.
Approximately 75% of cellulosic materials such as cellulose and hemi-cellulose were decomposed during a 194 h composting period under
50% moisture conditions. Rather rapid decomposition of cellulosic materials, which is characteristic of the composting of grass clippings,
was observed.
Accelerated Composting of Grass Clippings By Controlling Moisture LevelKiyohiko Nakasaki, Nobuto Aoki, Hiroshi Kubota
Waste Manag Res January 1994 vol. 12 no. 1 13-20
Effects of controlling moisture level on
composting of grass clippings were examined by measuring changes in
CO2 evolution rate, conversion of carbon, HPLC pattern of water
soluble organic matter and concentrations of organic matter constituents in the composting solid, during the composting process.
Sumber: ….. Diunduh 20/4/2012
Lama pengomposan Lama waktu pengomposan tergantung pada karakteristik bahan yang
dikomposakan, metode pengomposan yang dipergunakan dan dengan atau tanpa penambahan aktivator pengomposan. Secara alami pengomposan akan
berlangsung dalam waktu beberapa minggu sampai 2 tahun hingga kompos benar-benar matang.
. Kondisi yang optimal untuk mempercepat proses pengomposan (Ryak, 1992)
FAKTOR-FAK TOR PENGOMPOSAN
KondisiKonsisi yang bisa
diterimaIdeal
Rasio C/N 20:1 s/d 40:1 25-35:1
Kelembaban 40 – 65 % 45 – 62 % berat
Konsentrasi oksigen tersedia
> 5% > 10%
Ukuran partikel 1 inchi bervariasi
Bulk Density 1000 lbs/cu yd 1000 lbs/cu yd
pH 5.5 – 9.0 6.5 – 8.0
Suhu 43 – 66oC 54 -60oC
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm#TopOfPage ….. Diunduh 20/4/2012
Pengomposan dapat dipercepat dengan beberapa strategi. Secara umum strategi untuk mempercepat proses pengomposan dapat dikelompokan
menjadi tiga, yaitu:Menanipulasi kondisi/faktor-faktor yang berpengaruh pada proses
pengomposan.Menambahkan Organisme yang dapat mempercepat proses pengomposan:
mikroba pendegradasi bahan organik dan vermikompos (cacing).Menggabungkan strategi pertama dan kedua.
MEMANIPULASI KONDISI PENGOMPOSAN
Strategi ini banyak dilakukan di awal-awal berkembangnya teknologi pengomposan. Kondisi atau faktor-faktor pengomposan dibuat seoptimum
mungkin. Sebagai contoh, rasio C/N yang optimum adalah 25-35:1. Untuk membuat kondisi ini bahan-bahan yang mengandung rasio C/N tinggi dicampur dengan bahan yang mengandung rasio C/N rendah,
seperti kotoran ternak. Ukuran bahan yang besar-besar dicacah sehingga ukurannya cukup kecil dan ideal untuk proses pengomposan. Bahan yang
terlalu kering diberi tambahan air atau bahan yang terlalu basah dikeringkan terlebih dahulu sebelum proses pengomposan. Demikian pula
untuk faktor-faktor lainnya.
STRATEGI MEMPERCEPAT PENGOMPOSAN
Supplemental nutritionThe techniques mentioned above often need to be complemented by the
provision of nutrients. One of the most common practices is to add inorganic fertilizers, particularly N, in order to modify a high C:N ratio. Similarly, P is sometimes applied as the C:P ratio of the material mix is also considered
important (the ratio should be between 75:1 and 150:1). When micro-organisms are inoculated, they require sugar and amino acids in order to boost their initial
activities; molasses is often added for this purpose.
MENGGUNAKAN AKTIVATOR PENGOMPOSANStrategi yang lebih maju adalah dengan memanfaatkan organisme yang dapat
mempercepat proses pengomposan. Organisme yang sudah banyak dimanfaatkan misalnya cacing tanah. Proses pengomposannya disebut
vermikompos dan kompos yang dihasilkan dikenal dengan sebutan kascing. Organisme lain yang banyak dipergunakan adalah mikroba, baik bakeri,
aktinomicetes, maupuan kapang/cendawan.
Saat ini dipasaran banyak sekali beredar aktivator-aktivator pengomposan, misalnya : Green Phoskko (GP-1), Promi, OrgaDec, SuperDec, ActiComp,
EM4, Stardec, Starbio, BioPos, dan lain-lain.
Promi, OrgaDec, SuperDec, dan ActiComp adalah hasil penelitian Balai Penelitian Bioteknologi Perkebunan Indonesia (BPBPI) dan saat ini telah
banyak dimanfaatkan oleh masyarakat.
Aktivator pengomposan ini menggunakan mikroba-mikroba terpilih yang memiliki kemampuan tinggi dalam mendegradasi limbah-limbah padat organik, yaitu: Trichoderma pseudokoningii, Cytopaga sp, Trichoderma
harzianum, Pholyota sp, Agraily sp dan FPP (fungi pelapuk putih). Mikroba ini bekerja aktif pada suhu tinggi (termofilik).
Aktivator yang dikembangkan oleh BPBPi tidak memerlukan tambahan bahan-bahan lain dan tanpa pengadukan secara berkala. Namun, kompos perlu ditutup/sungkup untuk mempertahankan suhu dan
kelembaban agar proses pengomposan berjalan optimal dan cepat. Pengomposan dapat dipercepat hingga 2 minggu untuk bahan-bahan
lunak/mudah dikomposakan hingga 2 bulan untuk bahan-bahan keras/sulit dikomposkan.
STRATEGI MEMPERCEPAT PENGOMPOSAN
Sumber: http://en.wikipedia.org/wiki/Methanogenesis….. Diunduh 20/4/2012
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
Memanipulasi Kondisi dan Menambahkan Aktivator Pengomposan
Strategi proses pengomposan yang saat ini banyak dikembangkan adalah mengabungkan dua strategi di atas. Kondisi pengomposan dibuat seoptimal
mungkin dengan menambahkan aktivator pengomposan.
Profil suhu dan populasi mikroba selama proses pengomposan
Panas dihasilkan dari aktivitas mikroba. Ada hubungan langsung antara peningkatan suhu dengan konsumsi oksigen. Semakin tinggi temperatur akan semakin banyak
konsumsi oksigen dan akan semakin cepat pula proses dekomposisi. Peningkatan suhu dapat terjadi dengan cepat pada tumpukan kompos.
Temperatur yang berkisar antara 30 - 60oC menunjukkan aktivitas pengomposan yang cepat. Suhu yang lebih tinggi dari 60oC akan membunuh sebagian mikroba dan hanya
mikroba thermofilik saja yang akan tetap bertahan hidup.
STRATEGI MEMPERCEPAT PENGOMPOSAN
Sumber: http://id.wikipedia.org/wiki/Kompos ….. Diunduh 20/4/2012
Strategi pengomposan
Seringkali tidak dapat menerapkan seluruh strategi pengomposan di atas dalam waktu yang bersamaan. Ada beberapa pertimbangan yang dapat
digunakan untuk menentukan strategi pengomposan:
1.Karakteristik bahan yang akan dikomposkan.2.Waktu yang tersedia untuk pembuatan kompos.3.Biaya yang diperlukan dan hasil yang dapat dicapai.4.Tingkat kesulitan pembuatan kompos
Strategi Mempercepat Proses PengomposanPengomposan dapat dipercepat dengan beberapa strategi. Secara umum strategi untuk mempercepat proses pengomposan dapat dikelompokan
menjadi tiga, yaitu:1.Menanipulasi kondisi/faktor-faktor yang berpengaruh pada proses pengomposan.2.Menambahkan Organisme yang dapat mempercepat proses pengomposan: mikroba pendegradasi bahan organik dan vermikompos (cacing).3.Menggabungkan strategi pertama dan kedua.
STRATEGI MEMPERCEPAT PENGOMPOSAN
Memanipulasi Kondisi Pengomposan
Kondisi atau faktor-faktor pengomposan direkayasa menjadi seoptimum mungkin. Misalnya rasio C/N yang optimum adalah 25-35:1. Untuk
membuat kondisi ini bahan-bahan yang mengandung rasio C/N tinggi dicampur dengan bahan yang mengandung rasio C/N rendah, seperti
kotoran ternak. Ukuran bahan direkayasa sehingga ukurannya cukup kecil dan ideal
untuk proses pengomposan. Bahan yang terlalu kering diberi tambahan air atau bahan yang terlalu basah dikeringkan terlebih dahulu sebelum
proses pengomposan. Demikian pula untuk faktor-faktor lainnya.
Sumber: Temperature and soil organic matter decomposition rates – synthesis of current knowledge and a way forward. RICHARD T. CONANT dkk. Global Change Biology (2011) 17,
3392–3404, doi: 10.1111/j.1365-2486.2011.02496.x
Lines indicate OM fluxes, with the dashed line signifying the OM flux associated with enzyme production and its contribution to OM depolymerisation. Red arrows (and red
arrowheads) indicate that rates accelerate with increasing temperature while those in blue indicatethat rates slow with warming temperatures. Black arrows are fluxes for which temperature controls are poorly understood (e.g., type of OM released from chemical protection) or beyond the scope of this review (plant inputs). Physical protection slows
depolymerization of otherwise available SOM and exchange of chemically protected SOM, but its response to temperature is not well understood. Temperature response of chemical
protection varies as a function of the type of binding (covalent bonds are effectively irreversible on short time-frames) and bonding affinity (temperature effects on diffusion
processes dominate for low-affinity mineral-bound SOM while desorption dynamics dominate for high-affinity SOM). As physiochemically protected SOM becomes available for
decomposition some may be assimilable, but we expect that most will require depolymerization before it can be assimilated by microbes.
MODEL DEKOMPOSISI BAHAN ORGANIK
Bagan (a) Representation of the negative relationship between enzyme-binding ability and catalytic rate as a result of the trade-off between enzyme conformational structures that maintain binding (as opposed to non-binding)
states vs. higher reaction rates. Bagan (b) Idealized thermal sensitivities of the activities of respiratory
enzymes resulting as a consequence of the trade-off shown in (a) [based on Angilletta (2009)], where the black curve is from the coolest environment and
the dot-hatch blue curve from the warmest.
KATALISIS ENSIMATIS
Sumber: Temperature and soil organic matter decomposition rates – synthesis of current knowledge and a way forward. RICHARD T. CONANT dkk. Global Change Biology (2011) 17,
3392–3404, doi: 10.1111/j.1365-2486.2011.02496.x
Composting is the process of controlled aerobic decomposition of biodegradable organic matter
During composting, microorganisms break down organic matter into carbon dioxide, water, heat, and compost:
Organic matter + O2
Compost + CO2 + H2O + NO3- + SO4
2- + heat
PENGOMPOSAN
Sumber: http://soils.ifas.ufl.edu/academics/pdf/Non-Thesis%20Projects/Travis%20Roberts.pdf ….. Diunduh 23/4/2012
ORGANIC MATTER DECOMPOSITION: INTERACTIONS OF TEMPERATURE, MOISTURE AND SUBSTRATE TYPE
Travis Roberts, Professional MS StudentSoil and Water Science Department, University of Florida
The decomposition of organic matter is a major biogeochemical process because of its effect on ecosystem productivity and its implications on climate change. Temperature and moisture
are two variables that have a tremendous influence on microbial decomposition.
Decomposition is also influenced by substrate type, in which higher quality substrates often have greater decomposition than lower quality substrates.
Pine and hardwood litters, popsicle sticks, aspen and pine wood stakes were subjected to 4 temperature treatments (10ºC, 20ºC, 30ºC, and 40ºC) and 4 moisture content treatments
(wet 23-28%, moist 15-20%, dry 3-7%, & fluxing between 3-7% and 23-28% saturation ) over the course of 30 months, in order to determine the influence of temperature, moisture, and
substrate type on decomposition. As a subset of the experiment soil respiration was recorded from one pvc collar with leaf litter and one without litter and was subjected to the
same treatments.
There were different responses with different substrates, but overall microbial decomposition was greatest at the highest temperatures. For the wood substrates the “moist” and “dry”
moisture contents generally produced the highest mass losses. The pvc collar’s highest soil respiration rates were with the “wet” moisture treatment. Temperature and moisture are both significant in decomposition, but the moisture relationship interaction with decomposition is
much harder to understand.
BAHAN-BAHAN UNTUK PENGOMPOSAN
Food and drink industry waste; Paper, card, timber and other biodegradable waste; Limbah rumah tangga; Organic sludge including sewage; Limbah atau sisa-sisa pertanian.
: Wastes from meat, dairy products, and eggs should not be used in household compost:
they attract unwanted vermin;they do not appropriately decompose in the
time required.
Biodegradability of the Organic Fraction of Municipal Solid Waste in a High-Solids Anaerobic Digester
Masoud KayhanianWaste Manag Res March 1995 vol. 13 no. 2 123-136
Three methods were used to estimate the ultimate biodegradability of the organic fraction of municipal solid waste.
These methods included: long-term batch digestion studies, measurement of lignin content, and chemostat studies. The ultimate biodegradability values
obtained from these methods were compared to a field operation using a pilot scale, high-solids, complete-mix, thermophilic, anaerobic digestion process.
The biodegradability obtained from the pilot study, at a mass retention time of 30 days, was approximately 83 and
81% of the estimated values obtained from the lignin content and the batch study, respectively.
In addition, it has been shown that the contents of the biodegradable volatile solids affects the prediction of biogas production rate, the computation of the organic loading rate,
and feedstock C/N ratio. .
Sumber: http://wmr.sagepub.com/content/13/2/123.abstract ….. Diunduh 20/4/2012
DEKOMPOSERDEKOMPOSER
Klasifikasi mikroba menurut konsumsi oksigen nya: Aerobik: Mikroba menggunakan oksigen untuk metabolismenya
Anaerobik: Mikroba dapat hidup aktif dalam lingkungan tanpa oksigen bebas.
Mikroba asdalah kunci dari proses pengomposan
RELATIONSHIP OF MICROBIAL MASS AND ACTIVITY IN BIODEGRADATION OF SOLID WASTE
R.J. Murphy, D.E. Jones, R.I. StesselWaste Manag Res September 1995 vol. 13 no. 5 485-497
Limited landfill space and resistance to siting such facilities has spurred consideration of new approaches to increase the longevity of landfills. Such
efforts have included exploring methods to enhance degradation rates of municipal solid waste (MSW) and subsequently, mining landfills to recover
materials and landfill space.
Microbial mass and activity of MSW incubated in lysimeters, with moisture content sustained with recycled leachate, were compared under anaerobic and aerobic conditions in this study. Bacterial biomass and number were quantified by adenosine triphosphate analysis and acridine orange direct counts. Viability, adenylate energy charge and cellulase activity were also
assessed. Bacterial number and energy status were lower in the anaerobic system.
Cellulase activity in the anaerobic lysimeter decreased to undetectable levels while activity in the aerobic system continued to increase throughout the 92-
day experiment.
The results indicated that aeration, even at a relatively low volume, with leachate recirculation,
significantly accelerated degradation of MSW. Furthermore, the results demonstrated the potential of using cellulase activity as a surrogate parameter of relative microbial activity of MSW degradation. Sumber: http://wmr.sagepub.com/content/13/5/485.abstract ….. Diunduh 20/4/2012
Klasifikasi Mikroba menurut kondisi thermal kehidupannya:
MikrobaKisaran Temperatur
untuk aktivitasnya, оС
Psychrophiles Mesophiles Thermophiles
0 - 3030 – 45 45 – 50
Waste Manag. 2008;28(8):1411-6. Epub 2007 Sep 27.Optimum moisture levels for biodegradation of mortality composting
envelope materials.Ahn HK, Richard TL, Glanville TD.
Moisture affects the physical and biological properties of compost and other solid-state fermentation matrices. Aerobic microbial systems experience
different respiration rates (oxygen uptake and CO2 evolution) as a function of moisture content and material type. In this study the microbial respiration rates of 12 mortality composting envelope materials were measured by a pressure
sensor method at six different moisture levels. A wide range of respiration (1.6-94.2mg O2/g VS-day) rates were observed for different materials, with
alfalfa hay, silage, oat straw, and turkey litter having the highest values. These four envelope materials may be particularly suitable for improving internal temperature and pathogen destruction rates for disease-related mortality
composting. Optimum moisture content was determined based on measurements across a range that spans the maximum respiration rate. The optimum moisture content of each material was observed near water holding
capacity, which ranged from near 60% to over 80% on a wet basis for all materials except a highly stabilized soil compost blend (optimum around 25% w.b.). The implications of the results for moisture management and process
control strategies during mortality composting are discussed.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/17900890 ….. Diunduh 28/4/2012
PERTUMBUHAN MIKROBA SELAMA PROSES PENGOMPOSAN
Microorganisms Populations according to the
thermal conditions
<40 оС 40 - 70 оС
BACTERIA Mesophiles Thermophiles
ACTINOMICETES Thermophiles
FUNGI MesophilesThermophiles
108
104
104
106
106
106
109
108
103
107
Biotechnol Bioeng. 2004 Nov 20;88(4):520-7.Monitoring the biological activity of the composting process: Oxygen uptake rate (OUR), respirometric index (RI), and respiratory quotient
(RQ).Gea T., Barrena R, Artola A, Sánchez A.
Composting of several organic wastes of different chemical composition (source-separated organic fraction of municipal solid waste, dewatered raw
sludge, dewatered anaerobically digested sludge and paper sludge) was carried out under controlled conditions to study the suitability of different
biological indexes (oxygen uptake rate, respirometric index, and respiratory quotient) to monitor the biological activity of the composting process. Among
the indexes tested, oxygen uptake rate (also referred to as dynamic respirometric index) provided the most reliable values of microbial activity in a
compost environment. On the other hand, values of the static respirometric index measured at process temperature, especially in the early stages of the
composting process, were significantly lower than those of the dynamic index, which was probably due to oxygen diffusion limitations present in static
systems. Both static and dynamic indexes were similar during the maturation phase. Static respirometric index measured at 37 degrees C should not be
used with samples obtained during the thermophilic phase, since it resulted in an underestimation of the respiration values. Respiratory quotient presented only slight variations when changing the process temperature or the waste considered, and its use should be restricted to ensure aerobic conditions in
the composting matrix.Sumber: http://www.ncbi.nlm.nih.gov/pubmed/15459907 ….. Diunduh 28/4/2012
Bacteria Heterotrophic Autotrophic Aerobic Anaerobic
Kemampuan pertumbuhannya sangat besar opada media lembab
Spektrum aktivitasnya sangat luat
Aktif pada kondisi kisaran pH yang luas
Sulit beradaptasi pada kondisi media masam
BIOREMEDIATION OF OLIVE-MILL WASTEWATERS BY COMPOSTING
U. Tomati, E. Galli, L. Pasetti, E. VolterraWaste Manag Res November 1995 vol. 13 no. 6 509-518
Olive-mill wastewaters (O.M.W.) containing about 7% solids were composted with wheat straw in a forced aeration static pile. Two percent urea was added to ensure a C/N ratio of about 35. To avoid overdosing with water, a fraction of
the O.M.W. equal to the weight of the straw was added initially. When composting had reached the thermophilic phase, additional doses of O.M.W.
were added every 3 days as water evaporated.
The ratio of O.M.W. solids:straw approached 1:1 and the thermophilic phase was extended to 35 days. Temperature, oxygen consumption, pH, C/N, total
organic carbon, total extractable carbon, humic and fulvic acids and lignin degradation were followed during the process. The humification was assayed following the degree of humification, the humification rate and the humification index which respectively reached the values of 78%, 37.8% and 0.28 after 2
months.
Humic acids were characterized by their elemental composition and molecular weight. A lignin degradation of about 70% was assayed at the end of the
thermophilic phase. No phytotoxicity was recorded on the end product, the chemical and physical properties of which suggest its possible use as fertilizer.
Sumber: http://wmr.sagepub.com/content/13/6/509.abstract ….. Diunduh 20/4/2012
Fungi
Mampu hidup pada medium yang kandungan airnya rendah;
Kompetitor bagi bakteri heterotrophic
Aktif pada konduisi pH 2 – 9;
Kebutuhan nitrogen nya rendah
Fermenting fungi
Ragi = Yeast
ENUMERATION OF ANAEROBIC REFUSE-DECOMPOSING MICRO-ORGANISMS ON REFUSE CONSTITUENTS
Xingdong Qian, Morton A. BarlazWaste Manag Res March 1996 vol. 14 no. 2 151-161
Hydrolytic, acetogenic and methanogenic bacteria are required for the conversion of refuse to methane in landfills. In order to identify sources of these trophic groups in refuse, the total anaerobic population and the sub-
populations of cellulolytic, hemicellulolytic, butyrate catabolizing acetogenic, and acetate- and H2-CO2 -utilizing methanogenic bacteria as present on grass,
leaves, branches, food waste, whole refuse and two landfill cover soils were enumerated by the most probable number (MPN) technique. Total anaerobes ranged from 10 3 cells per dry gram in cover soil to 109 in grass, food waste
and fresh refuse.
Hemicellulolytics ranged from 160 cells per dry gram in cover soil to 109 in grass. The highest cellulolytic population was measured on branches (316
cells per dry gram), while the maximum acetogenic population was measured on leaves (2.5 x 104).
The highest methanogen populations were measured on leaves (6.3 x 103) and one of two fresh refuse samples (105).
Yard waste was the major carrier of the trophic groups required for refuse decomposition, while the cover soils tested did not represent major inputs of
the requisite bacteria to landfills.
Sumber: http://wmr.sagepub.com/content/14/2/151.abstract ….. Diunduh 20/4/2012
Actinomycetes Aerobic and thermophilic;
They are assimilated by bacteria and fungi;
use organic nitrogen;
Active in neutral and slightly alkaline media;
Act in the ending phase of the composting process.
Waste Manag Res. 2006 Feb;24(1):37-47.THE USE OF RESPIRATION INDICES IN THE COMPOSTING
PROCESS: A REVIEW.Barrena Gómez R, Vázquez Lima F, Sánchez Ferrer A.
Respiration is directly related to the metabolic activity of a microbial population. Micro-organisms respire at higher rates in the presence of large amounts of bioavailable organic matter while respiration rate is slower if this type of material is scarce. In the composting process respiration activity has
become an important parameter for the determination of the stability of compost. It is also used for the monitoring of the composting process and it is
considered an important factor for the estimation of the maturity of the material. A wide range of respirometric protocols has been reported based either on CO2 production, O2 uptake or release of heat. The most common
methods are those based on O2 uptake.
Respirometric assays are affected by a number of parameters including temperature, humidity, and both incubation and pre-
incubation conditions. Results from respirometries are generally expressed as 'respiration indices', most of them with
their own units and basis. In consequence, some confusion exists when referring and comparing respiration indices.
This is particularly important because current and future legislations define and measure the biological stability of waste on the basis of respiration activity of the material. This paper discusses and compares most common respiration
indices currently used.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/16496869 ….. Diunduh 28/4/2012
Pelaku lain dalam proses dekomposisi bahan organik
Duckweeds (algae)
Cyanophytes
Prothozoe
Enzymes
COMPOSTING OF < 100 MM FRACTION OF MUNICIPAL SOLID WASTE
S. Mato, D. Otero, M. Garcia
A low cost solution for management of municipal solid waste in small municipalities was investigated; composting experiments were done
using domestic waste. Particles > 100 mm were removed, the screened substrate ( < 100 mm)
was used for composting experiments on static piles.
The results have shown that the size of waste does not affect composting. Though the inert material left greatly
adds to the porosity, rainfall does not markedly affect the process; in fact excessive dryness gave the least stable end product, and total nitrogen, ammoniacal
nitrogen and phosphorus content were the best pointers to the instability.
Sumber: http://wmr.sagepub.com/content/12/4/315.abstract ….. Diunduh 20/4/2012
ShreddingDownsizing, or chopping up the materials, is a sound and widely-
practised technique. It increases the surface area available for microbial action and provides better aeration. This technique is
particularly effective and necessary for harder materials such as wood.
Diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm
1. Pelaku utamanya mikroba aerobik;2. Terjadi proses Dekomposisi bahan organik (asam organik, asam amino,
sakarida); 3. Mengkonsumsi oksigen dan melepaskan CO2 dan energi;4. Proses dekompiosisi berlangsung cepat;5. Temperatur dapat mencapai 55-60° С.
I. Fase Pertama: Aktif (Termofilik)
Kinetic Study of the Composting of Evergreen Oak Forestry WasteM.-J. Martinez-Iñigo, G. Almendros
Waste Manag Res July 1994 vol. 12 no. 4 305-314
The successive stages in the composting process of forestry waste from evergreen oak (Quercus ilx sbsp. ballota) were studied under controlled
conditions (initial) carbon to nitrogen ratio = 30, T= 27°C). The original material was composted for 6 months and sampled every 15
days.
The variables measured on the oak biomass in the course of the experiment showed different kinetics: the weight loss and germination index underwent a
monotonic increase whereas the reducing sugars, phenols and E465/ E665 extinction ratio of the water-soluble fraction stabilized at their lowest values
after the first 2 weeks. Other variables, such as alkali solubility, water repellency, pH and particle size, showed maximum or minimum values at
intermediate stages of the experiment. In contrast to the adverse agrobiological effects of the direct application to soil of the original waste,
germination biotests and greenhouse experiments showed that plant response improved from the 2 first weeks of composting.
The kinetics observed for the parameters studied suggested that the less favourable effect on plant yield may come from
phytotoxic substances in compost but also from the microbial use of soil N required for the transformation of the
most biodegradable compost fractions in special hemicelluloses. Sumber: http://wmr.sagepub.com/content/12/4/305.abstract ….. Diunduh 20/4/2012
Perubahan Temperatur selama fase pertama proses dekomposisi biomasa yang tingkat
fermentasinya rendah atau tinggi
The active composting stage is followed by a curing stage, and the pile temperature decreases gradually. The start of this phase is identified when
turning no longer reheats the pile. At this stage, another group of thermophilic fungi starts to grow. These fungi bring about a major phase of decomposition of plant cell-wall materials such as cellulose and hemi-cellulose. Curing of the
compost provides a safety net against the risks of using immature compost such as nitrogen (N) hunger, O deficiency, and toxic effects of organic acids
on plants.Eventually, the temperature declines to ambient temperature. By the time composting is completed, the pile becomes more uniform and less active biologically although mesophilic organisms recolonize the compost. The
material becomes dark brown to black in colour. The particles reduce in size and become consistent and soil-like in texture. In the process, the amount of
humus increases, the ratio of carbon to nitrogen (C:N) decreases, pH neutralizes, and the exchange capacity of the material increases.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm ….. Diunduh 26/4/2012
Sumber: http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2011.02496.x/abstract ….. Diunduh 22/4/2012
The response of soil organic matter (OM) decomposition to increasing temperature is a critical aspect of ecosystem responses
to global change. The impacts of climate warming on decomposition dynamics have not been resolved due to apparently contradictory results from field and lab experiments, most of which has focused on labile carbon with short turnover times. But the majority of total soil carbon stocks are comprised of organic carbon with turnover
times of decades to centuries. Understanding the response of these carbon pools to climate change is essential for forecasting longer-term changes in soil carbon storage. Herein, we briefly synthesize information from recent studies that have been conducted using a
wide variety of approaches.
It explicitly defines resistance of soil OM to decomposition as being due either to its chemical conformation (quality) or its physico-chemical protection from decomposition.
The former is embodied in the depolymerization process, the latter by adsorption/desorption and aggregate turnover.
We hypothesize a strong role for variation in temperature sensitivity as a function of reaction rates for both. We conclude that important advances in understanding the
temperature response of the processes that control substrate availability, depolymerization, microbial efficiency, and enzyme production will be needed to predict
the fate of soil carbon stocks in a warmer world.
Temperature and soil organic matter decomposition rates – synthesis of current knowledge and a way forward
Richard T. Conant , Michael G. Ryan, Göran I. Ågren, Hannah E. Birge, Eric A. Davidson, Peter E. Eliasson, Sarah E. Evans, Serita D. Frey, Christian P. Giardina, Francesca M. Hopkins, Riitta Hyvönen, Miko U. F. Kirschbaum, Jocelyn M. Lavallee, Jens Leifeld, William J. Parton, Jessica
Megan Steinweg, Matthew D. Wallenstein, J. Å. Martin Wetterstedt, Mark A. Bradford. Global Change Biology. Volume 17, Issue 11, pages 3392–3404, November 2011
In our effort to understand research to-date, we derive a new conceptual model that explicitly identifies the processes controlling soil OM availability for
decomposition and allows a more explicit
description of the factors regulating OM decomposition under
different circumstances.
Dekomposisi molekul organik yang lebih kompleks;
Kebanyakan mikroba mati kekurangan makanan;
Proses dekomposisi berlangsung lambat; Temperatur mencapai 40 - 45° С; Durasinya: beberapa minggu
: humifikasi
Wujud bahan organik sebelum dan setelah Pengomposan
FASE KE DUA PROSES DEKOMPOSISI: Cooling
FASE KE TIGA: PEMATANGAN
Temperatur sama dengan suhu ambient;
Hasilnya berupa kompos matang dengan kualitas bagus
Temperature changes and fungi populations in wheat straw compost.Solid line = temperature; broken line = mesophilic fungi population; dotted line = thermophilic fungi population; left y-axis = fungal populations (logarithm of colony forming units (cfu) per gram of compost plated onto agar); right y-axis = temperature in centre of compost. a, b, c
and d = heating phases.Source: http://helios.bto.ed.ac.uk/bto/microbes/thermo.htm
The aerobic composting process starts with the formation of the pile. In many cases, the temperature rises rapidly to 70-80 °C within the first couple of days. First, mesophilic
organisms (optimum growth temperature range = 20-45 °C) multiply rapidly on the readily available sugars and amino acids. They generate heat by their own metabolism and raise the
temperature to a point where their own activities become suppressed. Then a few thermophilic fungi and several thermophilic bacteria (optimum growth temperature range = 50-
70 °C or more) continue the process, raising the temperature of the material to 65 °C or higher. This peak heating phase is important for the quality of the compost as the heat kills
pathogens and weed seeds.
(diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm 26/4/2012)
PARAMETER PENGENDALI KOMPOSTING
1. Porosity of substrate (free volume) – defined by the spaces inside the biomass occupied by air and water.
Pg = Vv / Vt , %
Free air space (FAS), Vf Vf - the biomass volume, which is occupied by the air:
(Vv –Va) / Vt
Va – volume, occupied by
water
Porosity depends on:
Particle size distribution;
Level of humidity;
Height of the pail.
General porosity Pg - the relation of empty spaces volume Vv and the whole biomass volume Vt:
Sumber: ….. Diunduh 20/4/2012
Effective cross sectional area as a function of particle size distribution, shape, and packing density
1. The particle size
distribution, bulk density,
and porosity of a compost
mixture are group of
factors that can lead to
anaerobic conditions.
2. These physical
characteristics of the compost
mixture can interact with high moisture
levels to reduce oxygen
transport.
Sumber: ….. Diunduh 20/4/2012
2. AIR - KELEMBABAN
• Air diperlukan dalam proses pertukaran unsur hara melalui membran sel;
• Air menjadi media transport bagi ensim-ensim ekstra-seluler;
• Air menjadi medium bagi senyawa-senyawa larut;
• Air diperlukan untuk berlangsungnya reaksi-reaksi kimia
Optimal m
oisture:
50 – 60%
< 40% moisture – degradation will proceed at a slow rate (under 25 -30% it stops);
> 65% moisture - О2 distributes very difficult in the biomass (anaerobic conditions established)
Air merupakan salah satu komponen penting bagi kehidupan mikroba, karena:
Factors affecting aerobic composting
AerationAerobic composting requires large amounts of O, particularly at the initial stage. Aeration is the source of O, and, thus, indispensable for aerobic
composting. Where the supply of O is not sufficient, the growth of aerobic micro-organisms is limited, resulting in slower decomposition. Moreover,
aeration removes excessive heat, water vapour and other gases trapped in the pile. Heat removal is particularly important in warm climates as the risk of overheating and fire is higher. Therefore, good aeration is indispensable
for efficient composting. It may be achieved by controlling the physical quality of the materials (particle size and moisture content), pile size and
ventilation and by ensuring adequate frequency of turning.
MoistureMoisture is necessary to support the metabolic activity of the micro-
organisms. Composting materials should maintain a moisture content of 40-65 percent. Where the pile is too dry, composting occurs more slowly, while a moisture content in excess of 65 percent develops anaerobic conditions. In practice, it is advisable to start the pile with a moisture content of 50-60
percent, finishing at about 30 percent.(diunduh dari: http://www.fao.org/docrep/007/y5104e/y5104e05.htm)
The effect of aqueous film thickness on anaerobic odor production
Metabolic Regions as a function
of moisture content
In a properly moist compost matrix, the particles
(brown) are surrounded by aqueous films (blue), but are separated by air filled
pores (white)
Anaerobic zones (purple dots) are created as
increasing water content fills small pores, so oxygen
must diffuse farther through water.
Sumber: http://www.fao.org/docrep/007/y5104e/y5104e05.htm ….. Diunduh 26/4/2012
Composting may be divided into two categories by the nature of the decomposition process. In anaerobic composting, decomposition occurs
where oxygen (O) is absent or in limited supply.
Under this method, anaerobic micro-organisms dominate and develop intermediate compounds including methane, organic acids, hydrogen
sulphide and other substances. In the absence of O, these compounds accumulate and are not metabolized further.
Many of these compounds have strong odours and some present phytotoxicity. As anaerobic composting is a low-temperature process, it leaves weed seeds and pathogens intact. Moreover, the process usually
takes longer than aerobic composting. These drawbacks often offset the merits of this process, viz. little work
involved and fewer nutrients lost during the process.
JUMLAH OKSIGEN
C6H12O6 + 6O2 → 6CO2 + 6H2O + 2 800 KJ/mol
To treat 1kg organic matter 1,6 kg of O2 are required !
Oxygen requirement during the composting process:
First stage – 5 - 15%
Second stage – 1 - 5%
Air: 10 – 100 N.m3/h
O2 could be supplied by means
of:
Mechanical mixing;
Forced ventilation (aeration )
Complete mineralization? Humification?
Result:
Temperature:
: t > 70C kills also bacteria
responsible for composting process!
Defines the thermophilic stage of the composting process;
Easy to monitor
Provides disinfection of the product - at 55C almost all pathogenic are killed;
Kills the weeds’ seeds at 65C and more
First stage: 55-65C
Second stage: 35 - 45C
t< 25C end of the composting process
Values of released energy for Values of released energy for main substances:main substances:
Glucosis 19 kJ/gGlucosis 19 kJ/g
Lipides 39 kJ/gLipides 39 kJ/g
Proteines 23 kJ/gProteines 23 kJ/g
Temperature is a key parameter determining the success of composting process!
Heat is produced as a by-product of the microbial breakdown of
organic material
M. Koleva ERASMUS’07
Temperature and pH profiles during composting
Ratio C/N, C/P and C/SRatio C/N, C/P and C/S
naturally existing in naturally existing in biomassbiomass
C C – source of energy for heterotrophic – source of energy for heterotrophic microorganisms;microorganisms;
NN – important for syntesis of protheins – important for syntesis of protheins
C 1/3 digunakan oleh
mikroba
2/3 menjadi CO2
30 atoms 30 atoms C C : 1 : 1 atom atom NN
C/N > 30
•Inhibited
decomposing
process;
•Increased
composting time
C/N < 30 •Excess of N that leads to
release of NH3
•NH3 is stimulated by: t , N,
pH
C/N:ImportantImportant: balanced
: balanced ratio ratio C/NC/N
C/P:P acts as a catalyst of
biochemical reactions!Optimal ratio: 100 < C/P< 200
C/S:Optimal ratio: 100 < C/S< 300
Optimal ratio C/N:
•at the start 25 -30
•At the end < 20 (10:1)
Carbon-to-nitrogen ratios may need to be adjusted
depending on the bioavailability of these elements !!!
Materials High in Carbon C/N*
autumn leaves 30-80:1
straw 40-100:1
wood chips or sawdust 100-500:1
bark 100-130:1
mixed paper 150-200:1
newspaper or corrugated cardboard
560:1
Materials High in Nitrogen C:N*
vegetable scraps 15-20:1
coffee grounds 20:1
grass clippings 15-25:1
manure 5-25:1
Typical C/N ratios for common compost materials
Source: Dickson, N., T. Richard, and R. Kozlowski. 1991. Composting to Reduce the Waste Stream: A Guide to Small
Scale Food and Yard Waste Composting
Sumber: ….. Diunduh 20/4/2012
KEMASAMAN : pHKEMASAMAN : pH
I st period:: pH value decreases
The reason: generation of CO2
II nd period: pH value increases up to 8-9
The reason: generation of NH3
Optimal values of pH are:
at the beginning pH 5.5 8
at the end: pH 7
pH max 8.5
5
6
7
8
9
pH
0 Time
I II
Compost microorganisms
operate best under neutral to
acidic conditions!
Factors Leading to Anaerobic Conditions
1. Inadequate porosity
3. Excess moisture
4. Rapidly degrading substrate
2. Excessive pile size
oxygen cannot
move into a pile
reduces oxygen
penetration
Oxygen is consumed
much more
rapidly
Sumber: ….. Diunduh 20/4/2012
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/14987816 ….. Diunduh 28/4/2012
. Oxygen concentration plays an important role in the regulation of methane oxidation and the microbial ecology of methanotrophs. However, this effect is
still poorly quantified in soil and compost ecosystems.
The effect of oxygen on the formation of exopolymeric substances (EPS) is as yet unknown. We studied the effect of oxygen on the evolution of
methanotrophic activity.
At both high and low oxygen concentrations, peak activity was observed twice within a period of 6 months. Phospholipid fatty acid analysis showed that there was a shift from type I to type II methanotrophs during this period. At high oxygen concentration, EPS production
was about 250% of the amount at low oxygen concentration. It is hypothesized that EPS serves as a carbon cycling mechanism for type I methanotrophs when inorganic nitrogen is limiting. Simultaneously,
EPS stimulates nitrogenase activity in type II methanotrophs by creating oxygen-depleted zones. The kinetic results were incorporated in a simulation model for gas transport and methane oxidation in a passively
aerated biofilter.
Comparison between the model and experimental data showed that, besides acting as a micro-scale diffusion
barrier, EPS can act as a barrier to macro-scale diffusion, reducing the performance of such biofilters.
Environ Pollut. 2004 May;129(2):305-14.Methane oxidation and formation of EPS in compost: effect of oxygen
concentration.Wilshusen JH, Hettiaratchi JP, De Visscher A, Saint-Fort R.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/15288296 ….. Diunduh 28/4/2012
The methane oxidation potential of several types of compost methanotrophic biofilter columns were compared in the laboratory
over a period of 220 days. The results indicate an increase in methanotrophic activity over a
period of about 100 days, up to a maximum of 400 g m(-2) day(-1), and a gradual decline to about 100 g m(-2) day(-1) within the next
120 days.
High methane oxidation rates appear to be restricted to a small area of the column, 10-15 cm thick. Based on the
laboratory investigations carried out to determine the cause for the decline in methane oxidation rate, it was
concluded that the formation of exopolymeric substances (EPS), at the zones of maximum methane oxidation, was
responsible for this decline.
In monitoring methane oxidation in a column for up to 600 days, it was observed that mixing of the medium after formation of EPS enabled the column to temporarily
recover high performance.
The results suggest that stable, homogenous compost, with a low C/N and low ammonium content, mixed on a regular basis, could achieve and maintain high methane
oxidation efficiencies.
Waste Manag. 2004;24(7):643-53.Long-term behavior of passively aerated compost methanotrophic biofilter
columns.Wilshusen JH, Hettiaratchi JP, Stein VB.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19584243….. Diunduh 28/4/2012
Landfill gas containing methane is produced by anaerobic degradation of organic waste. Methane is a strong greenhouse gas and landfills are one of the major anthropogenic sources of
atmospheric methane.
Landfill methane may be oxidized by methanotrophic microorganisms in soils or waste materials utilizing oxygen that
diffuses into the cover layer from the atmosphere.
The methane oxidation process, which is governed by several environmental factors,
can be exploited in engineered systems developed for methane emission mitigation.
Mathematical models that account for methane oxidation can be used to predict methane
emissions from landfills.
Additional research and technology development is needed before methane mitigation technologies utilizing microbial
methane oxidation processes can become commercially viable and widely deployed.
Waste Manag Res. 2009 Aug;27(5):409-55. Epub 2009 Jul 7.Microbial methane oxidation processes and technologies for mitigation of
landfill gas emissions.Scheutz C, Kjeldsen P, Bogner JE, De Visscher A, Gebert J, Hilger HA, Huber-
Humer M, Spokas K
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18338700 ….. Diunduh 28/4/2012
Landfill gases produced during biological degradation of buried organic wastes include methane, which when released to the atmosphere, can contribute to global climate change. Increasing use of gas collection systems has reduced
the risk of escaping methane emissions entering the atmosphere, but gas capture is not 100% efficient, and further, there are still many instances when
gas collection systems are not used.
Biotic methane mitigation systems exploit the propensity of some naturally occurring bacteria to oxidize methane.
By providing optimum conditions for microbial habitation and efficiently routing landfill gases to where they are cultivated, a number of bio-based systems,
such as interim or long-term biocovers, passively or actively vented biofilters, biowindows and daily-used biotarps, have been developed that can alone, or
with gas collection, mitigate landfill methane emissions
This paper reviews the science that guides bio-based designs; summarizes experiences with the diverse natural or
engineered substrates used in such systems; describes some of the studies and field trials being used to evaluate them; and discusses how they can be
used for better landfill operation, capping, and aftercare.
Waste Manag Res. 2008 Feb;26(1):33-46.Biotic systems to mitigate landfill methane emissions.
Huber-Humer M, Gebert J, Hilger H
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/14987816 ….. Diunduh 28/4/2012
Oxygen concentration plays an important role in the regulation of methane oxidation and the microbial ecology of methanotrophs. However, this effect is
still poorly quantified in soil and compost ecosystems.
The effect of oxygen on the formation of exopolymeric substances (EPS) is as yet unknown. We studied the effect of oxygen on the evolution of
methanotrophic activity. At both high and low oxygen concentrations, peak activity was observed twice within a period of 6 months.
Phospholipid fatty acid analysis showed that there was a shift from type I to type II methanotrophs during this
period. At high oxygen concentration, EPS production was about 250% of the amount at low oxygen
concentration. It is hypothesized that EPS serves as a carbon cycling mechanism for type I methanotrophs when inorganic
nitrogen is limiting. Simultaneously, EPS stimulates nitrogenase activity in
type II methanotrophs by creating oxygen-depleted zones. The kinetic results were incorporated in a simulation model for gas transport and methane
oxidation in a passively aerated biofilter. Comparison between the model and experimental data showed that, besides acting as a micro-scale diffusion
barrier, EPS can act as a barrier to macro-scale diffusion, reducing the performance of such biofilters.
Environ Pollut. 2004 May;129(2):305-14.Methane oxidation and formation of EPS in compost: effect of oxygen
concentration.Wilshusen JH, Hettiaratchi JP, De Visscher A, Saint-Fort R
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/15288296….. Diunduh 28/4/2012
The methane oxidation potential of several types of compost methanotrophic biofilter columns were compared in the laboratory
over a period of 220 days.
The results indicate an increase in methanotrophic activity over a period of about 100 days, up to a maximum of 400 g m(-2) day(-1), and a gradual decline to about 100 g m(-2) day(-1) within the next
120 days. High methane oxidation rates appear to be restricted to a small area
of the column, 10-15 cm thick.
Based on the laboratory investigations carried out to determine the cause for the decline in methane oxidation rate,
it was concluded that the formation of exopolymeric substances (EPS), at the zones of maximum methane
oxidation, was responsible for this decline.
In monitoring methane oxidation in a column for up to 600 days, it was observed that mixing of the medium after
formation of EPS enabled the column to temporarily recover high performance.
The results suggest that stable, homogenous compost, with a low C/N and low ammonium content, mixed on a regular
basis, could achieve and maintain high methane oxidation efficiencies.
Waste Manag. 2004;24(7):643-53.Long-term behavior of passively aerated compost methanotrophic biofilter
columns.Wilshusen JH, Hettiaratchi JP, Stein VB
DECOMPOSITION
• Many organisms are very beneficial in ecosystems as decomposers.
• Breakdown of organic matter recycles nutrients
• Decomposition = important for recycling of C and energy, as well as all nutrient elements (N, P, K, etc.).
Sumber: http://whatcom.wsu.edu/ag/compost/fundamentals/biology_aerobic.htm … diunduh 21/4/2012
Mesophylic bacteria thrive from 70° to 90° F, but just survive at temperatures above and below (40° to 70° F, and 90° to 110° F) In many backyard piles, these mid range bacteria do most of the work. However,
if conditions are right, they produce enough heat to activate the “thermophilic,” or heat loving bacteria. Thermophilic bacteria work fast.
Their optimum temperature range is from 104° to 160° F.High temperatures destroy pathogenic bacteria and protozoa (microscopic one celled animals), and weed seeds, which are
detrimental to health and agriculture when the final compost is used on the land.
Biological activity diminishes if the compost mix contains too much carbon in relation to nitrogen. Several cycles of
organisms are required to burn excess carbon. This is a complex chemical process. When organisms die, their stored nitrogen and carbon become available to other
organisms. These new organisms form new cells which again need nitrogen to burn excess carbon and produce
CO2. Thus, the amount of carbon is reduced and the limited amount of nitrogen is recycled. Finally, when the ratio of
available carbon to available nitrogen is low enough, nitrogen is released as ammonia. Under favorable conditions, some ammonia may oxidize to nitrates.
Phosphorus, potash, and various micronutrients are also essential for biological growth. These are normally present in more than adequate amounts in compostable materials.
TIPE-TIPE DEKOMPOSISI
• Proses Abiotik - fire, etc.
OM + O2 CO2, etc.• Proses Biotik:
– Aerobic respiration
OM + O2 CO2, etc.– Anaerobic respiration
OM CH4, etc.• Mikroba yang bertanggung-jawab langsung untuyk dekomposisi
bahan organik adalah bacteria dan fungi.
Sumber: http://whatcom.wsu.edu/ag/compost/fundamentals/biology_aerobic.htm … diunduh 21/4/2012
Organic material decomposing with oxygen is an "aerobic" process. When living organisms that use oxygen feed upon organic matter, they develop cell
protoplasm from the nitrogen, phosphorus, some of the carbon, and other required nutrients. Carbon serves as a source of energy for organisms and is
burned up and respired as carbon dioxide (CO2). Since carbon serves both as a source of energy and as an element in the cell protoplasm, much more
carbon than nitrogen is needed. Generally, organisms respire about two-thirds of the carbon they consume as CO2, while the other third is combined with
nitrogen in the living cells.
Biological activity diminishes if the compost mix contains too much carbon in relation to nitrogen. Several cycles of organisms are required
to burn excess carbon. This is a complex chemical process. When organisms die, their stored nitrogen and carbon become available to other organisms. These new organisms form new cells which again need nitrogen to burn excess carbon and produce CO2. Thus, the amount of carbon is reduced and the limited amount of nitrogen is
recycled. Finally, when the ratio of available carbon to available nitrogen is low
enough, nitrogen is released as ammonia. Under favorable conditions, some ammonia may oxidize to nitrates. Phosphorus, potash, and
various micronutrients are also essential for biological growth. These are normally present in more than adequate amounts in compostable
materials.
LAJU DEKOMPOSISI
• Decomposition rates vary (measured in litter bags), depending on:
– Climate and temperature
– Soil organisms present
– Aeration of the soil
– Composition of the material (C:N ratio)
– Etc.– season, tillage
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html … diunduh 21/4/2012
PENTINGNYA C/N RATIOMicroorganisms that digest compost need about 30 parts of carbon for every part of nitrogen they consume. That's a balanced diet for them. If there's too much nitrogen,
the microorganisms can't use it all and the excess is lost in the form of smelly ammonia gas. Nitrogen loss due to excess nitrogen in the pile (a low C:N ratio) can
be over 60%. At a C:N ratio of 30 or 35 to 1, only one half of one percent of the nitrogen will be lost. That's why you don't want too much nitrogen (fresh manure, for example) in your compost: the nitrogen will be lost in the air in the form of ammonia gas, and nitrogen is too valuable for plants to allow it to escape into the atmosphere.
The four conditions that are constant for all residue decomposition:1.A maximum of 35% of the carbon in fresh organic material will be converted into soil humus IF there is sufficient nitrogen present.2.A minimum of 65% of the carbon in fresh organic material will be given off to the atmosphere as carbon dioxide due to microbial respiration. (Uh-oh! An argument could be made that composting contributes to greenhouse gases and warming of the Earth's atmosphere. However, consider this, nature is always decomposing everywhere; so, what you are doing in your little compost bin is a mere iota of carbon release compared to nature's vast compost bin in forests, rangeland, etc.)3.The humus formed from the decomposition of fresh organic material will contain approximately 50% carbon and 5% nitrogen. In other words, the C:N ratio of the humus is 10:1.4.Most fresh plant material contains 40% carbon. The C:N ratio varies because of differences in nitrogen content, not carbon content. (Note: Dry materials are generally in the range of 40 to 50 percent carbon, and sloppy, wet materials are generally 10 to 20 percent carbon. Therefore, the most important factor in estimating the carbon-to-nitrogen ratio of plant or food waste is how much water is present).
LAJU DEKOMPOSISI
• Laju dekomposisi sangat beragam, tergantung pada:
– Iklim dan temperature
– Organisme tanah yang ada
– Aerasi tanah
– Composition of the material (C:N ratio)
– Kondisi musim, pengolahan tanah, dll
Temperature mempengaruhi laju dekomposisiSedikit bahan organik di daerah iklim panas
Sumber: http://whatcom.wsu.edu/ag/compost/fundamentals/biology_aerobic.htm … diunduh 26/4/2012
Temperature plays a huge role on the speed an item decomposes. The higher the temperature in an area, the faster an object in that area will decompose.
Heat makes objects decompose more rapidly than they would if they were in a cooler temperature. In the decomposition process, bacteria will eat compost,
which will then cause it to slowly disintegrate. When the atmosphere is cooler, the air will kill the bacteria, which would then slow down the process of decomposition. This happens because when the bacteria is weaker, the
decomposition of the object will not happen as fast.
When carbon is oxidized to CO2, a great deal of energy is released as heat. For example, if a gram of glucose molecules is dissimilated under aerobic conditions, 484 to 674 kilogram calories (kcal) of heat may be
released. If organic material is in a large enough pile or arranged to provide some insulation, temperatures during decomposition may rise to over 170° F. At temperatures above 160° F, however, the bacterial activity decreases.
There are many different kinds of bacteria at work in the compost pile. Each type needs specific conditions and the right kind of organic material. Some
bacteria can even decompose organic material at temperatures below freezing. These are called psychrophilic bacteria, and although they work
best at around 55°, they continue to work down to 0° F. As they work, they give off small amounts of heat. If conditions are right, this heat will be
enough to set the stage for the next group of bacteria, the “mesophylic,” or middle range temperature bacteria.
• Decomposition rates vary (measured in litter bags), depending on:
– Climate and temperature– Soil organisms present– Aeration of the soil– Composition of the material (C:N ratio)– Etc.– season, tillage
• Season: spring = fresh green material; fall = tough residues• Tillage: aerates soil
LAJU DEKOMPOSISI
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html … diunduh 21/4/2012
PENTINGNYA C/N RATIOFor microorganisms, carbon is the basic building block of life and is a source of energy, but nitrogen is also necessary for such things as proteins, genetic
material, and cell structure.
Balance of C:N is KeyDecomposition of organic materials in your compost pile is greatly increased
when you create the proper balance between the carbonaceous materials (called BROWN because they are dry) and the nitrogen-rich materials (called
GREEN because they are more fresh and moist).
In compost , this balance is referred to as the Carbon-Nitrogen ratio, and shown as C:N.
For best performance, the compost pile, or more to the point the composting microorganisms, require the correct proportion of Carbon for energy and
Nitrogen for protein production. Compost scientists have determined that the fastest way to produce fertile, sweet-smelling compost is to maintain a C:N
ratio somewhere around 25 to 30 parts Carbon to 1 part Nitrogen, or 25-30:1. If the C:N ratio is too high (excess Carbon), decomposition slows down. If the
C:N ratio is too low (excess nitrogen) you will end up with a stinky pile.
C:N ratio
• Slower decomposition if C:N ratio is high.• Examples of C:N ratios…..
All organic matter is made up of substantial amounts of carbon (C) combined with lesser amounts of nitrogen (N). The balance of
these two elements in an organism is called the carbon-to-nitrogen ratio (C:N ratio).
For best performance, the compost pile, or more to the point the composting microorganisms, require the correct proportion of
carbon for energy and nitrogen for protein production. Scientists (yes, there are compost scientists) have determined that the fastest way to produce fertile, sweet-smelling compost is to
maintain a C:N ratio somewhere around 25 to 30 parts carbon to 1 part nitrogen, or 25-30:1. If the C:N ratio is too high (excess carbon), decomposition slows down. If the C:N ratio is too low
(excess nitrogen) you will end up with a stinky pile.
Below are the average C:N ratios for some common organic materials found in the compost bin. For our purposes, the
materials containing high amounts of carbon are considered "browns," and materials containing high amounts of nitrogen are
considered "greens."
Sumber: http://www.composting101.com/c-n-ratio.html … diunduh 21/4/2012
C:N Ratios BEBERAPA MACAM MATERIAL
PENTINGNYA C:N RATIO
• With residues of high C:N, there is much competition for the limited N available.
• If C:N ratio is high:– only some organisms can decompose (some
types of bacteria and fungi, protozoan symbionts of termites).
– they use up N quickly, so N becomes tied up and unavailable (immobilized).
Sumber: http://www.omafra.gov.on.ca/english/crops/field/news/croptalk/2010/ct-1110a7.htm … diunduh 21/4/2012
High C:N RatiosThe carbon to nitrogen ratio of soil is about 10:1. When solid manure or other organic material has a C:N ratio of greater than 30:1, there is a higher risk that the soil bugs will "steal" nitrogen from the soil and
tie it up. Therefore this nitrogen is unavailable to a crop while breaking down the carbon material. A crop with higher nitrogen
requirements, such as corn or wheat, will show nitrogen deficiencies in that situation. When a material has a C:N ratio less than 20:1,
there is generally enough nitrogen in the organic
Material C:N Ratio Range
Soil Microbes 4:1 to 9:1
Soil Organic Matter 10:1 to 12:1
Solid Cattle Manure20:1 (light bedding) to40:1 (heavy bedding)
Horse Manure27:1 (straw bedding)60:1 (sawdust bedding)
Solid Poultry Manure5:1 layers10:1 broilers and turkeys
Liquid Hog Manure < 8:1
Liquid Dairy 15:1
Legume Residues 20:1 to 30:1
Corn Stalks 80:1
Wheat Straw 80:1
Sawdust 500:1
Pulp & Paper biosolids25:1 (nitrogen added during process) to200:1 (little or no nitrogen added)
Organic N
Inorganic N
Mineralization
Immobilization Bacteria take scarce N for themselves !
Bacteria free up N
PENTINGNYA C:N RATIO
Sumber: http://www.omafra.gov.on.ca/english/crops/field/news/croptalk/2010/ct-1110a7.htm … diunduh 21/4/2012
. Nitrogen Deficiency and Carbon:Nitrogen Ratios of Organic Ammendments
"Carbon to nitrogen ratio inbalance" is a term used to describe a type of nitrogen deficiency. Farmers from my grandfather's generation called it "sour
soil". A field recently had pulp and paper biosolids applied. The newly planted crop looked great, until the seedlings ran out of seed reserves and started utilizing soil nutrients. The crop then turned a neon shade of yellow. What happened?
Organic-N & Ammonium-NWhen an organic amendment is applied to a field, it adds nutrients and organic
matter to the soil. The organic matter contains about 60 percent organic carbon. The carbon:nitrogen (C:N) ratio shows the proportion of organic
carbon to total nitrogen of a manure or organic material. Nitrogen is a food source for the micro-organisms ("soil bugs") while they
break down organic carbon. The nitrogen can come from the added organic material or it can come from the soil. During the process of carbon breakdown soil microbes die and decompose. The microbial nitrogen is then returned to
the soil and becomes available to the plants. This adds to the organic nitrogen pool within the soil along with the added organic material. How long the carbon
breakdown process takes depends on the ratio of carbon to nitrogen in the material and in the soil.
PENAMBAHAN N-ORGANIK KE TANAH
Organic N materials
decompose, release nitrate
Adding organic N to soil
Organic N materials decompose, release nitrate
Nitrate used in decomposition process by bacteria, etc.
PENAMBAHAN N-ORGANIK KE TANAH BAHAN YANG MEMPUNYAI C/N RASIO RENDAH
Decomposition and
release of nitrate is
fast, levels recover quickly
Adding organic N to soilHigh C:N ratio material
Nitrate release
difficult, tied up for a
long time
N rob = immobility of N in presence of residues with high C:N ratios
Nitrate release difficult, tied up
for a long time
Risky Mix of High and Low C:N
High C:N residue + Inorganic N fertilizer =
N from fertilizer immobilized by bacteria
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html … diunduh 21/4/2012
BAGAIMANA MENGGUNAKAN C:N RATIO
Principle 1: Ratio yang ideal 30:1A hot, fast pile (with temperatures up to 140°F/60°C) is obtained when the C:N
ratio of all the materials you add averages 30:1 (50:1 is adequate for most slower, lower-temperature piles). You can be sure, then, that the little
microbes are stuffing themselves.This ratio describes the chemical composition of a material and does not
mean that you need a volume of brown materials that is thirty times greater than the amount of green matter.
Graphic courtesy of University of Missouri Extension Service
PENTINGNYA C:N RATIO
• As C:N ratio goes lower (as it does during decomposition), more organisms (especially fungi, different bacteria types, even some insects) can join in, so decomposition proceeds much faster.
• Most insects and other animals join later in the process, as the C:N ratio of their food is low:
– e.g., fungi 10:1, decomposed animals 6:1, nematodes 10:1.
Sumber: … diunduh 21/4/2012
Principle 2: Dua bagian hijau dan satu bagian coklat
(The best stragey to mix your compostable materials)
Generally speaking, you can get C:N ratios of 30:1 to 50:1 by adding two parts of a GREEN material to one part of a
BROWN material to your bin.
A "part" can be defined as a certain quantity of the material, such as two 5-gallon buckets of GREEN and 1
packed bucket of BROWN.
For example, food scraps, grass clippings and leaves come close to an average of 30:1. How? Add-up the Carbon side of the ratio for all three materials, i.e. 15, 17, 60, and divide by
the number of materials, i.e. three. 92/3 = about 31:1.
PENGOMPOSAN = COMPOSTING
• Mempercepat proses dekomposisi bahan organik• Mereduksi (menurunkan) C:N ratio• Suhu tinggi: 60-80oC (140-175oF)• Bakteri Thermophilic• Banyak tersedia teknologinya
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html … diunduh 21/4/2012
The best combination would be a mixture of GREEN sources, as shown on the left of the chart
below and a BROWN source such as leaves (notice that leaves have a fairly low C:N ratio
compared to other carbonaceous materials shown on the right of the chart.
Leaves are ideal for composting. Researchers have determined that effective
compost can be made with equal parts GREEN and BROWN, or with 2 parts GREEN and 1 part
BROWN.
PENGOMPOSAN = COMPOSTING
Sumber: http://www.homecompostingmadeeasy.com/carbonnitrogenratio.html… diunduh 21/4/2012
Use this Rule of Thumb when viewing the chart belowAny organic matter that has a C:N ratio generally smaller than 30:1 is considered a
GREEN.Any organic matter that has a C:N ratio generally larger than 30:1 is considered a BROWN.
Common Home Compostable Materials & C:N Ratios(Example: Food Scraps has a Carbon:Nitrogen Ratio of 17:1,
meaning 17 parts Carbon to 1 part Nitrogen)GREEN (Nitrogen) BROWN (Carbon)
Aged Chicken Manure 7:1
Fresh manures are way to hot and can burn your plants and roots!
Leaves 60-80:1One of the most important ingredients for composting,
especially shredded or broken down (leaf mulch).
Food Scraps 17:1
Vegetable Scraps 25:1
Straw, Hay 90:1
The best way to use is to shred for faster breakdown.
Coffee Grounds 25:1Sawdust 500:1
Commercially produced compost is high in sawdust or shredded bark chips. Use very sparingly!
Grass Clippings - Fresh 17:1
Dry clippings would be higher in Carbon. Therefore, use as carbon source if necessary.
Woody chips & twigs 700:1
Be sparing. Best use is small material at bottom of bin or pile.
Fresh Weeds 20:1
Make sure you don't compost weeds with seeds, unless you insure that your pile gets hot - over 140°F/60°C.
Shredded Newspaper 175:1
Has no nutrient content. Best used in vermicomposting. Always shred and soak in water for fast breakdown.
Fruit Wastes 25-40:1 Nut shells 35:1
Rotted Manure 20:1
Horse manure should not be used because it contains undigested seeds that can sprout in the bin.
Pine Needles 80:1
Use sparingly. Very acidic and waxy; breaks down slowly.
Humus (soil) 10:1
This is nature's natural ratio. Use sparingly in pile. Best used to "seal" the pile by putting a 1-2 inch layer on top.
Corn Stalks 60:1
Shred or cut up in small pieces for fast break down.
Seaweed 19:1Peat Moss 58:1
Has no nutrient value. In the bin it is mostly filler.
General Garden Waste 30:1
Clippings from plants, stalks, dead flowers, etc. Excellent mix with leaves
NOTEThe C:N Ratios given in this chart are average and may slightly vary according to source, researcher or scientist!
RANGKAIAN PROSES DEKOMPOSISI
• Berlaku untuk bahan organik dari tumbuhan• Bahan organik dari hewan mempunyai nuilai C/N rendah,
mudah di-dekomposisi oleh hewan, dll.
soil animals bacteria, fungi soil chemistryOrganic detritus humus mineralizationmaterial (small particles)(litter)
Sumber: http://urbanext.illinois.edu/compost/process.cfm … diunduh 21/4/2012
The composting processThe composting process involves four main components: organic matter, moisture, oxygen,
and bacteria. Organic matter includes plant materials and some animal manures. Organic materials used
for compost should include a mixture of brown organic material (dead leaves, twigs, manure) and green organic material (lawn clippings, fruit rinds, etc.). Brown materials
supply carbon, while green materials supply nitrogen. The best ratio is 1 part green to 1 part brown material. Shredding, chopping or mowing these materials into smaller pieces will help
speed the composting process by increasing the surface area.For piles that have mostly brown material (dead leaves), try adding a handful of commercial
10-10-10 fertilizer to supply nitrogen and speed the compost process.
Moisture is important to support the composting process. Compost should be comparable to the wetness of a wrung-out sponge. If the pile is too dry, materials will decompose very
slowly. Add water during dry periods or when adding large amounts of brown organic material. If the pile is too wet, turn the pile and mix the materials. Another option is to add
dry, brown organic materials.
Oxygen is needed to support the breakdown of plant material by bacteria. To supply oxygen, you will need to turn the compost pile so that materials at the edges are brought to
the center of the pile. Turning the pile is important for complete composting and for controlling odor.
Wait at least two weeks before turning the pile, to allow the center of the pile to "heat up" and decompose. Once the pile has cooled in the center, decomposition of the materials has
taken place. Frequent turning will help speed the composting process.
Bacteria and other microorganisms are the real workers in the compost process. By supplying organic materials, water, and oxygen, the already present bacteria will break
down the plant material into useful compost for the garden. As the bacteria decompose the materials, they release heat, which is concentrated in the center of the pile.
You may also add layers of soil or finished compost to supply more bacteria and speed the composting process. Commercial starters are available but should not be necessary for
compost piles that have a proper carbon to nitrogen ratio (1 part green organic material to 1
Sumber: http://afabjournal.com/articles/using-mortality-compost-in-vegetable-production-a-comparison-between-summer-and-winter-composting-and-its-use-in-cabbage-production/ …..
Diunduh 22/4/2012
. A study was conducted to determine the effectiveness of composting to
breakdown the carcasses of daily poultry mortality and in the process destroy
pathogenic microorganisms that may be present.
The results show that while winter composting can effectively breakdown poultry carcasses and attain high temperatures, summer compost is more efficient and had
consistently higher temperatures.
. Using Mortality Compost in Vegetable Production: A comparison between summer and winter composting and its use in cabbage productionC. S. Dunkley, D. L. Cunningham, C. W. Ritz, K. D. Dunkley, A. Hinton
Agriculture, Food and analytical Bacteriology (AFAB). Published 05/2011. volume 1 issue 1. Pp. 6-1
The study was conducted during the summer and repeated in the winter to determine whether the time
of year would affect the temperature profile or the length of time required for the process to be
completed. Daily mortalities were collected from a nearby producer and layered in a compost bin each day for four days. Samples were collected from the
litter before it was placed in the bin. Compost samples were collected every other day for a week after the bin was compiled and then once per week until the process was completed. The samples were evaluated for microbial content. Temperature was
taken and recorded at random points in the bins on a daily basis. Upon completion of the composting
process, the material was used as a soil amendment in two vegetable plots while a third plot without
compost material served as the control. Soil samples were collected from each of the plots prior to application of the compost material. Cabbage
seedlings were then planted in each of the plots. Vegetative samples and soil samples were collected and evaluated for microbial presence prior to planting
and at week, 1, 3, 7, and again at reaping. The summer compost had the highest temperature of 156°F on d 9 during the primary phase while the
winter compost had the highest temperature of 156°F on d 42 during the secondary phase of the compost.
The summer compost samples were Salmonella enterica (SE) negative from d 2 of the trial but mixed
bacterial colonies remained for the duration of the study. The vegetative samples in plot 1 had coliform levels of 3.48 log10/gm at wk10 but the levels was not considered significantly different from the other
two plots (p<0.05).
Sumber: http://wmr.sagepub.com/content/24/1/37.refs ….. Diunduh 22/4/2012
. Respiration is directly related to the metabolic activity of a microbial population. Micro-organisms respire at higher
rates in the presence of large amounts of bioavailable organic matter while respiration rate is slower if this type
of material is scarce. In the composting process respiration activity has become an important parameter
for the determination of the stability of compost. It is also used for the monitoring of the composting process and it
is considered an important factor for the estimation of the maturity of the material.
Results from respirometries are generally expressed as ‘respiration indices’, most of them with their own units and basis. In consequence, some confusion
exists when referring and comparing respiration indices.
This is particularly important because current and future legislations define and measure the biological stability of waste on the basis of respiration activity of the material. This paper discusses and compares most common respiration
indices currently used.
The use of respiration indices in the composting process: a reviewRaquel Barrena Gómez, Felicitas Vázquez Lima, Antoni Sánchez Ferrer
Waste Manag Res February 2006 vol. 24 no. 1 37-47
A wide range of respirometric protocols has been reported based either
on CO2 production, O2 uptake or release of heat.
The most common methods are those based on O2
uptake.
Respirometric assays are affected by a number of
parameters including temperature, humidity, and
both incubation and pre-incubation conditions.
Sumber: http://www.sciencedirect.com/science/article/pii/S0960852402001530….. Diunduh 22/4/2012
. To understand the relationships between temperature, moisture content,
and microbial activity during the composting of biosolids (municipal
wastewater treatment sludge),
. Fifty percent moisture content appeared to be the minimal requirement for obtaining activities greater than 1.0 mg g−1 h−1. Temperature was also
documented to be an important factor for biosolids composting. However, its effect was less influential than moisture content. Particularly, the
enhancement of composting activities induced by temperature increment could be realized by increasing moisture content alone.
. The influence of temperature and moisture contents regimes on the aerobic microbial activity of a biosolids composting blend
C Liang, K.C Das, , , R.W McClendonBioresource Technology. Volume 86, Issue 2, January 2003, Pages 131–137
Well-controlled incubation experiments were
conducted using a 2-factor factorial design with six
temperatures (22, 29, 36, 43, 50, and 57 °C) and five moisture contents (30, 40,
50, 60, and 70%). The microbial activity was
measured as O2 uptake rate (mg g−1 h−1) using a
computer controlled respirometer. In this study, moisture content proved to
be a dominant factor impacting aerobic microbial activity of the composting
blend
Sumber: http://www.sciencedirect.com/science/article/pii/S0045653503004892 ….. Diunduh 22/4/2012
. Microbial activity of an anthracene-spiked soil mixed with kitchen waste during
laboratory composting at 56–59 °C was studied using an in-vessel technology.
The results demonstrated that inoculating with old compost increased the amounts of thermophilic microorganisms, but did not significantly increase
anthracene removal. A microbial succession from mesophilic bacteria to thermophilic bacteria
and thermophilic actinomycetes was observed during composting.
Polyphenol oxidase activity decreased while catalase activity varied irregularly.
Microbial diversity increased drastically when temperature elevated from 35 to 56 °C, but decreased when temperature maintained at 56–59 °C.
. Microbial activity during composting of anthracene-contaminated soilY Ma, J.Y Zhang, M.H Wong
Chemosphere. Volume 52, Issue 9, September 2003, Pages 1505–1513
The effect of old compost containing acclimated microorganisms on the
composting efficiency was also investigated.
Microbial succession, microbial enzyme activity,
microbial diversity and anthracene removal rate were analyzed during 42
days of composting.
Sumber: http://www.sciencedirect.com/science/article/pii/0038071782900311….. Diunduh 22/4/2012
Bioresour Technol. 2004 May;93(1):49-57.Determination of aeration rate and kinetics of composting some
agricultural wastes.Kulcu R, Yaldiz O.
Significant loss of dry weight occurred at relative humidity and moisture content values of 32 and 5% respectively which are values much lower than
those at which microbial activity in other systems has been reported.
It is likely, however, that biological decomposition is not significant until relative humidity and moisture content values are above 75 and 13%
respectively.
Eucalyptus leaf-litter decomposition:
Effects of relative humidity and
substrate moisture content
L.A. Nagy, B.J. Macauley
Soil Biology and Biochemistry. Volume
14, Issue 3, 1982, Pages 233–236
A method to determine the effect of relative humidity
and substrate moisture content on
rates of decomposition of
Eucalyptus leaf litter is described.
This study aimed to determine the aeration rate and its kinetics in aerobic composting of agricultural wastes. For
this aim compost materials were prepared by mixing grass trimmings, tomato, pepper, and eggplant wastes. Four vertical forced aeration type reactors and one vertical
natural convection type reactor were manufactured to apply four different aeration rates. CO2 rate and temperature changes were recorded in three different places in the
reactors. Moisture content, pH and organic material rate were recorded each day. While process-monitoring
parameters (CO2, temperature, pH, moisture content) were used for interpretation of the process, organic material degradation was used for interpretation of the process
success. The seven different kinetic models were applied for modeling decomposition rate to the experimental values.
According to the results, four of these models were found applicable to this study. These models were analyzed with
some statistical methods as root mean square error (RMSE), chi-square (chi2), and modeling efficiency (EF).
According to the statistical results of these models, the best model was found as: [Formula: see text] where kT is the
rate of decomposition (g VS/g VS day); T the process temperature (degrees C); Mc the daily moisture content
(%wb); C the daily CO2 rate in composting reactor (%) and a, b, c, d are constants. According to the results, the highest
organic matter degradation and temperature value were obtained at the aeration rate of 0.4 l air min(-1)kg(om)(-1).
Thus, it could be applied to this mixed materials composting process.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002502.html….. Diunduh 22/4/2012
The cocomposting of agricultural waste is a new
management priority in Tunisia.
The composts studied were characterized by basic pH and an electric conductivity (EC) value ranging from 1.6 to 2.4 mS/cm. The organic matter contents (OM) and C/N ratios
of composts ranged from 20 to 46% and from 10 to 21%, respectively. Based on hydrophysical analyses, composts CI, CIII and CIV, containing AS, were shown to have a porosity and a water content of 10-26% and 10-20%, respectively. The phytotoxicity
of composts was studied on the basis of cress seed germination.
Results revealed that differences in properties are mainly related to the nature of composted waste and that some of these composts are
compatible for use as constituents in growing media for horticultural soilless cultures.
. Evaluation of Compost Maturity, Hydrophysical and Physicochemical Properties: Indicators for Use as a Component of Growing Media
Compost Science & Utilization, (2011), Vol. 19, No. 3, 226-234Manel Kammoun Rigane, Jean-Charles Michel, Khaled Medhioub and Philippe
Morel
In this study, four composts were evaluated by comparing the changes in
measured hydrophysical and physicochemical properties and
phytotoxicity. The organic wastes used were almond shell (AS), sesame bark (SB), olive husk (OH), and green and
wood wastes (GW and WW, respectively). Composts CI and CII
were composed of AS/SB and OH/SB, respectively, at a ratio of 75/25 (wet
weight basis). CIII consisted of OH, SB and CAS (coarsely-ground almond shell
used as a bulking agent) at a ratio of 55/25/20. Finally, CIV was composed of 25%SB+9%CAS+18%GW+48%WW.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002491.html….. Diunduh 22/4/2012
Elevated concentrations of carbon monoxide (CO) have been observed at the enclosed municipal waste composting
facility (ECF) in Edmonton, Canada. Elevated concentrations of CO in an
enclosed facility pose a potential health risk to workers.
These preliminary field measurements showed maximum CO concentrations of 112 µL L-1 within the compost. Autoclaved and non-sterilized compost samples from the ECF
were incubated under aerobic and hypoxic conditions, and gas emissions were quantified using gas chromatography (GC).
These trials showed a positive correlation between CO emission rate and incubation temperature for all samples, indicating a physico-chemical source of CO generation. Lower concentrations of CO were observed in the non-sterilized compost under both
aerobic and anaerobic conditions, presumably due to the microbial metabolism of CO.
. Emission of Carbon Monoxide During Composting of Municipal Solid WasteCompost Science & Utilization, (2011), Vol. 19, No. 3, 170-177
E.A. Phillip , O.G. Clark , K. Londry , S. Yu and J. Leonard
The objectives in this study were to: (1) assess temporal and spatial
variability of CO emissions from the composting bays in the ECF using Fourier Transform Infrared (FTIR) spectroscopy; and (2) identify any
correlations between the CO emission rate and the
physicochemical properties of the compost through bench-scale
incubation experiments. Repeated gas measurements were taken
above and within the compost bed in the ECF using a probe connected to
an FTIR gas analyzer, which continuously collected concentration
data.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002489.html….. Diunduh 22/4/2012
Wet olive husks represent an environmental problem in
Mediterranean areas but also a potential resource as recyclable
organic matter.
At the beginning of the composting process, protease and dehydrogenase activity, along with the microbial respiration, were higher in the piles with the starter, demonstrating a higher microbial activity in comparison with
the piles without the starter. At the end of the process, the compost with the starter showed a deeper humification and a lower content of total organic carbon with respect to
the compost without the starter, indicating a higher level of biodegradation and organic matter evolution.
The main outcome of this research includes the possibility to: (a) detoxify and de-odorize a bad-smelling waste into an hygienically safe product; (b) produce a green, mature, humified compost useful to restore soil fertility
and texture in intensive and organic agriculture.
. Composting Wet Olive Husks with a Starter Based on Oil-Depleted Husks Enhances Compost Humification
Compost Science & Utilization, (2011), Vol. 19, No. 3, 182-188M.C. Echeverria, R. Cardelli, S. Bedini, M. Agnolucci, C. Cristani, A. Saviozzi and M.
Nuti
In the present work, we describe the composting of wet olive husks, using
mechanically turned piles without forced
ventilation, carried out to study the effects of
partially composted oil-depleted husks as a starter for wet husks
degradation.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002488.html ….. Diunduh 22/4/2012
The high pH and electrical conductivity values of mature
compost from solid wastes of citrus processing plants can severely restrict
its use as a constituent of growing media in soilless cultivation.
In all potting mixtures the electrical conductivity never exceeded 0.7 dS m-1. Plant growth responses (i.e. fresh and dry biomass, together with root morphological parameters such as root length, surface area, fineness and tissue density) were
assessed on tomato and zucchini seedlings grown in potting mixtures under greenhouse conditions for 40 and 20 days, respectively.
The results indicated that orange waste compost induced species-specific and dose-dependent responses on plant growth. The growing rates were generally higher in
zucchini than in tomato seedlings; moreover, amendments larger than 7.5% determined a reduced growth rate in both plants which became more evident at 30% compost
doses. The same responses were induced on root morphological parameters: larger increases in root length, surface area, root dry weight, fineness and tissue density were observed in zucchini than in tomato; moreover, in both plants optimal morphological responses were found at 7.5% compost dose. Overall the results indicated that phosphoric acid
may efficiently be used to control high pH values in orange waste compost and make it suitable for wider use as a constituent of perlite-rich media provided the amendment
rates are carefully evaluated.
Growth of Tomato and Zucchini Seedlings in Orange Waste Compost Media: pH and Implication of Dosage
Compost Science & Utilization, (2011), Vol. 19, No. 3, 189-196Agostino Sorgonà, Maria Rosa Abenavoli, Giovanni Cacco and Antonio Gelsomino
In the present work, addition of phosphoric acid was used as a chemically feasible strategy to lower the pH of mature orange waste compost. The growing
media for testing were prepared by mixing commercial
perlite (Agrilit®3) with increasing dosages (0, 7.5, 15
and 30%, by vol) of orange waste compost after a pH
adjustement to 6.5-6.7 with the addition of phosphoric acid.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002487.html ….. Diunduh 22/4/2012
Compost is widely used as a natural soil conditioner and fertilizer supplement in gardening, planting and agriculture. Ability of compost to retain and release nutrients over time offers potential use
for control of excessive nutrient release to the environment; this ability may be further improved by
the addition of adsorbents to facilitate rapid retention of nutrients.
The adsorption capacity of goethite (1.18 mmol/g) was slightly higher than zeolite’s capacity (1.03 mmol/g). On the other hand, capacity of
humic acid was determined much lower (0.51 mmol/g).
The addition of fulvic acid resulted in a substantial reduction of adsorption capacities of all three adsorbents. Addition of 5.0 mmol/L of fulvic acid (as
carbon) decreased the adsorption capacity of phosphate by goethite, zeolite and humic acid by 94%, 88% and 82%, respectively.
Results of kinetics study indicated that the adsorption data fit the first-order kinetic model well with goethite exhibiting higher kinetic constants.
The results of this study suggest that metal oxide adsorbents such as goethite could be applied as additives into compost to improve the
nutrient holding ability.
Adsorption of Phosphate by Goethite and Zeolite: Effects of Humic Substances from Green Waste Compost
Compost Science & Utilization, (2011), Vol. 19, No. 3, 197-204Zhimang Gu, Fatih Büyüksönmez, Shashikanth Gajaraj and R. Edward Beighley
Therefore, we investigated the effects of humic substances extracted from green waste
compost on the adsorption of phosphate by goethite (a-
FeOOH) and zeolite (SiO2.Al2O3). Humic acid (4.66% by dry-weight) and
fulvic acid (1.26% as carbon/w) were extracted from finished compost and
purified.
Sumber: http://www.jgpress.com/compostscience/archive.html ….. Diunduh 22/4/2012
A concern regarding MSW compost quality is the trace
metal content.
Among the 7 types of contaminants, stainless steel screws, brass screws, and light bulb aluminum alloy thread contacts showed little weight
changes. This suggests minimum concerns for these materials in terms of metal release during composting. The highest metal release per unit area was from light bulb foot contacts, which was 3.66210-3 g cm-2,
while galvanized steel nails and zinc plated screw had a metal release rate in the range of 1.5 to 1.9210-3 g cm-2.
Scanning Electron Microscope (SEM) was employed to determine the chemistry of corrosion products and change of surface morphology by
corrosion and X-ray diffraction/spectrum to determine the type of corrosion products formed on the surface of some selected samples. As there is little literature on this subject, methodology and data from this work can be served as a scientifically sound reference to academics,
industry and legislators.
Trace Metals in Municipal Solid Waste Compost: Sources and Research Methodology
Compost Science & Utilization, (2011), Vol. 19, No. 2, 79-86Shouhai Yu , Daryl M. McCartney , Weixing Chen , Lixian Zhou and Salim Abboud
A study was initiated to assess the impact of various metal contaminants
on compost quality. One critical step in the study was to estimate metal
transfer during composting, which was achieved by measuring the corrosion rate of different contaminants during the high rate composting stage for 3 weeks using alfalfa hay and straw as
composting substrate. A corrosion quantification technique, weight
loss/gain of metal specimens, was employed to estimate metal release
into composting substrate.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002356.html ….. Diunduh 22/4/2012
A field survey was conducted to quantify the benefits of applying
compost to agricultural soils in California.
Across all sites, compost application increased soil organic carbon by 3x in comparison to control soils. Significant changes were also observed in soil microbial activity (2.23 x control), gravimetric water (1.57 x control),
and bulk density (0.87 x control). Nutrient availability in compost amended soils was similar to availability in conventionally managed soils. Infiltration times were significantly reduced in compost amended soils in
comparison to control soils.
High rates of compost application showed more significant benefits in comparison to low rates of compost application and control soils. At
lower application rates, compost amended soils were statistically similar to controls for most variables. Increases in water holding capacity were significant in coarser textured soils in comparison to finer textured soils.
Results from this sampling confirm results from replicated field trials on benefits associated with compost use in agricultural soils.
Changes in Soil Properties and Carbon Content Following Compost Application: Results of On-farm Sampling
Compost Science & Utilization, (2011), Vol. 19, No. 2, 87-96Sally Brown and Matt Cotton
Soil samples were collected from farm sites with a history of
compost use. Soils were analyzed for total organic carbon and
nitrogen, Mehlich III extractable nutrients, bulk density, microbial
activity (measured as CO2 evolution), water infiltration rate and gravimetric water at 1 bar
tension.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002352.html….. Diunduh 22/4/2012
The earthworm Eisenia fetida is the most commonly used worm for worm-supported composting of
organic residues.
E. fetida favored relatively moist soil with about 70% of the WHCmax and the most preferred concentration of fresh grass clippings within soil was 15% (v/v).
Pretreatments of the grass clippings like silage, precomposting or inoculation with the fungi Trichoderma viride and Geotrichum klebahnii were investigated and point to an
increased tolerance of the worms against pre-composted and inoculated grass whereas ensiled grass and remoistened hay was avoided.
The optimum concentration of ammonium for E. fetida was 18 µg NH4+-N g-1 DW soil although the worms could withstand much higher concentrations. Lactic and acetic
acid, intermediates that are quickly released from fresh lawn clippings under oxygen lacking conditions, were indicated to be the most important factors for preventing
worms from tolerating higher concentrations of grass clippings.
Use of Avoidance Tests for Investigating Potential of the Earthworm Eisenia fetida to Improve Composting of Grass Clippings
Compost Science & Utilization, (2011), Vol. 19, No. 2, 123-128Paul Illmer and Martin Liebensteiner
Within the present study, the potential of E. fetida for
decomposing grass clippings, an organic waste which usually
causes anoxic conditions and thus insufficient degradation in the
course of common composting, was investigated. To enable a
thorough investigation, the substrate-related requirements of E. fetida were studied using so-
called avoidance tests. These tests provide a sensitive method for evaluating the preferences and
aversions of soil animals related to substrate ingredients in a sublethal
range.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002351.html ….. Diunduh 22/4/2012
The use of olive mill wastewater (OMW) for composting was studied by the
addition of this liquid waste to a mixture of olive husks, poultry manure and
confectionery wastewater. The composting process was compared with that of another pile of similar composition, but without olive
mill wastewater.
The olive mill wastewater addition produced compost with higher organic matter concentrations and higher electrical conductivity, and a stabilized and humified organic
matter lower than the compost produced without olive mill wastewater.
The olive mill wastewater compost application to soil did not injure plants, producing a similar plant yield to both compost without olive mill wastewater and manure.
The olive mill wastewater compost application to soil also improved the chemical and physicochemical properties of the soil mainly fertilizing elements such as calcium,
magnesium, nitrogen, potassium and phosphorus. With respect to potato yield, both composts showed higher plant production in comparison to manure, reaching a potato
yield of 46 and 47 t/ha in amended soil with compost with and without OMW, respectively.
Cocomposting of Olive Mill Wastewater with Manure and Agro-industrial Wastes
Compost Science & Utilization, (2011), Vol. 19, No. 2, 129-134Hafedh Rigane and Khaled Medhioub
In order to study the effects of both composts
on plant yield and soil properties, a field
experiment was carried out with potato. Three
amendments were applied: manure and two composts with same rate
30 tonnes/ha.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002350.html….. Diunduh 22/4/2012
The acceleration effects of inoculum in composting of empty fruit bunches were
investigated.
The results showed that the inoculum was effective in reducing the C/N ratio by 54% compared to control 46% and rapidly increasing the UV-vis absorption ratio in first three weeks.By using functional microbes, the composting of empty fruit bunches was reduced to 5 weeks compared to 9 weeks for those without inoculation. The acceleration effect was more prominent for the 2 cm length samples.
Acceleration Effects of Microbial Inoculum on Palm Oil Mill Organic Waste Composting
Compost Science & Utilization, (2011), Vol. 19, No. 2, 135-142C.Y. Yeoh1, N.L. Chin , C.S. Tan and H.S. Ooi
Composting of empty fruit bunches fibres in two sizes, 4 cm and 2 cm length, were treated with microbial inoculum consisting of Agromonas, Aspergillus, Azotobacter, Bacillus,
Cellulomonas, Chaetomium, Clostridium, Coprinus, Microbispora,
Penicillium, Pseudomonas, Thermoactinomyces, Trichoderma and Trichurus in separate laboratory scale in-vessel of 30 liters volume. A control
without inoculum with 4 cm length empty fruit bunches was also
conducted in parallel. The compost piles were shift-turned weekly.
Parameters such as moisture content, temperature, pH, and electrical
conductivity were used to monitor the composting processes. The carbon-
nitrogen ratio, UV-vis spectrophotometer test, and
germination test were used to assess the maturity of compost.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002339.html ….. Diunduh 22/4/2012
Remediation of heavy metal in contaminated soils is necessary in order to alleviate the potential risks that they pose to both environment
and human health.
The results showed that the Pb, Cd and Zn concentrations were significantly reduced in the root and shoot of canola plant grown with the application of rice straw compost and WTR amendment. Extractability of
the metals was also significantly reduced in this treatment compared with the control.
The dry weight and root depth of canola plants were significantly increased with the application WTR and compost treatments at two
levels 10 or 20 mg kg -1 soil compared with the control. The addition of compost and WTR (2:1 or 1:1 wet weight ratio) at 10 g dry weight kg-1
dry soil gave the best reduction in the soil metal extractability and in and plant growth compared with other treatments.
Thus, the combination of rice straw compost and WTR was successful in lowering the bioavailability of metals and increasing yield of canola
grown on the contaminated soil.
HEAVY METAL REDUCTIONS IN SOILS AMENDED WITH COMPOST AND WATER TREATMENT RESIDUALS
Compost Science & Utilization, (2011), Vol. 19, No. 1, 69-73Esawy kasem Mahmoud
The present work was carried out to evaluate the
effect of rice straw compost, water treatment residuals
(WTR), and their mixture (2:1 and 1:1 wet weight), on
heavy metal immobilization in contaminated soils and on growth of canola (Brassica
napus).
Sumber: http://www.jgpress.com/compostscience/archives/_free/002340.html ….. Diunduh 22/4/2012
The use of oil palm empty fruit bunch, an agricultural waste from oil palm plantations, as a feeding material for earthworms during
composting provides an alternative source of nutrients for plants. Information regarding the
ability of earthworms in processing phosphorus-enriched empty oil palm fruit bunch and their effects on plants is still
lacking.
The soil treated with phosphorus-enriched vermicomposted empty oil palm fruit bunch increased the grass dry matter yield significantly higher compared to that treated with
composted empty oil palm fruit bunch and control. The root volume of vermicomposted- and composted- empty oil palm fruit bunches treated soil was similar but significantly greater than the control. There was significant interaction between dosage and type of growing media on cumulative N, P, K, Ca, and Mg
uptake. However, these factors did not show significant influence on total N, P, Ca and Mg in the soil amended with composted oil palm empty fruit bunch at the end of the experiment. In general, phosphorus-enriched vermicomposted- and phosphorus-enriched composted- empty oil palm fruit bunches treated soil resulted in a greater positive effect on growth and nutrient uptake of S. splendida, and also on the total nutrient content in soil except for total K. Total soil K in the control treatment was
242.0 mg/kg and significantly higher compared to soil treated with composted- (173 mg/kg) and vermicomposted- empty oil palm fruit bunches (167 mg/kg). The
vermicomposted empty oil palm fruit bunch resulted in better growth performance of the S. splendida in comparison to composted- and fresh- empty oil palm fruit bunches due to the readily available P and other nutrients being readily available to the plants.
Evaluation of Nutrients Released from Phosphorus-Enriched Empty Oil Palm Fruit Bunches As Growing Media Using Setaria splendidaCompost Science & Utilization, (2011), Vol. 19, No. 1, 61-68
D.T. Sabrina, M. M. Hanafi , T.M.M. Mahmud , and A.A. Nor Azwady
The objective of this study was to compare the effects
of phosphorus-enriched empty oil palm fruit bunches applied as fresh, composted or vermicomposted media in supplying nutrients on a test crop, Setaria splendida L., grass planted on Bungor (Typic Kandiudult) soil.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002342.html….. Diunduh 22/4/2012
This work aimed to determine whether composting reduced concentrations of plant toxins
(grayanotoxins) present in rhododendron leaves.
Similar degradation was not recorded in R. ponticum material stored outside at ambient temperatures. Degradation of the grayanotoxins present
in rhododendron is likely to occur during composting, and the amount of rhododendron material present in typical green waste compost windrows is
likely to be low. For these reasons, there is no need to exclude rhododendron from feedstock accepted on to UK PAS 100 accredited composting sites. The risk to livestock from grayanotoxin poisoning
through grazing grassland treated with PAS 100 green waste composts is likely to be negligible.
The Influence of Outdoor Windrow Composting On the Concentration of Grayanotoxins in Rhododendron Leaves
Compost Science & Utilization, (2011), Vol. 19, No. 1, 44-51David Michie , Audrey Litterick and Colin Crews
Bags of shredded R. ponticum leaves and twigs were buried in a
commercial compost windrow during a 12-week composting
process. Samples of R. ponticum tissue were tested for toxic grayanotoxins prior to the
composting process. Further samples were removed eight times
during the process and were analysed for grayanotoxins. Grayanotoxins-I and III were
present in the R. ponticum material prior to composting, but were found to degrade during the
composting process and were not detected in samples removed for testing 11 weeks after the start of
composting.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002344.html….. Diunduh 22/4/2012
The capability of organic wastes to release available N in soil varies largely,
depending on their source and form of production, or rather on their composition
and biodegradability.
Hot water extractable C and N of all organic amendments correlated well with short term C and N mineralization, except HCMC that immobilized N although its soluble N content was large. NCSOIL, a computer model that simulates C and N cycling in soil
with organic amendments, predicted well C and N mineralization of SS, SSC and CMC when considered as three-pool materials that decomposed at specific rates of 0.4,
0.024 and 10-4 d-1, using hot water soluble C and N as the labile pool. N immobilization by HCMC could be simulated only if the distribution of N between the
labile and resistant pools was derived by optimization of NCSOIL, while hot water soluble C was labile. Laboratory methods to determine an intermediate pool or
components that contribute to immobilization are required for improving the predictions of C and N mineralization from organic amendments.
Predicting Nitrogen and Carbon Mineralization of Composted Manure and Sewage Sludge in Soil
Compost Science & Utilization, (2011), Vol. 19, No. 1, 33-43R.S. Antil, A. Bar-Tal , P. Fine and A. Hadas
Our purpose was to predict mineralization rates of different materials using their analyses
joined with a simulation model, and to evaluate the influence of soil type and application rate of the organic materials on N and C transformations in soil. Four
organic materials, sewage sludge (SS), sewage sludge compost (SSC), cattle manure compost (CMC), hen and cattle manure
compost (HCMC), were applied to two soils at rates of 2 and/or 4%.
The soils were incubated aerobically for 168 days at 30oC, during which CO2 evolution rates
and mineral-N concentrations were measured periodically.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002345.html….. Diunduh 22/4/2012
Distributions of O2 and CO2 concentrations across a cross section of a full-scale passively aerated, mechanically turned,
compost pile were measured as a function of time over an 11 day long period covering two pile turnings.
Distributions of O2 and CO2 concentrations inside the pile were relatively constant with time and exhibited high O2 concentrations near the surface and high CO2
concentrations near the center of the pile. Maximum O2 fluxes into the compost occurred along the lower edges of the pile and
equalled up to 15 kg/m-2 h-1 while maximum CO2 fluxes occurred at the center top of the pile and equalled up to 700 g m-2 h-1.
Average daily CO2 emissions from the compost were up to 3.4 kg m3 d-1 while the corresponding O2 flux into the compost pile was up to 53 kg m3 d-1. Average O2
consumption was 1.4 kg m-3 d-1 while average CO2 production was 1.5 kg m-3 d-1 at the measurement location over the 11 day experimental period.
Oxygen and Carbon Dioxide Distribution And Movement in Passively Aerated Compost Piles
Compost Science & Utilization, (2011), Vol. 19, No. 1, 25-32Tjalfe G. Poulsen
The compost pile had a triangular cross section, was 1.8 m high, 4.4 m wide, 80 m long and consisted
of sewage sludge, yard/park waste and screening residue from
previously composted materials. The measurements were
conducted in one cross section of the pile. The O2 and CO2
concentration measurements were used in combination with earlier published measurements of air permeability and air pressure
inside the compost pile to calculate O2 and CO2 fluxes across the pile surface as functions of time and location as well as estimation of
total specific oxygen consumption rates in the compost.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002346.html….. Diunduh 22/4/2012
Soil degradation and water pollution are widespread land degradation problems in
Southeast Asia. Policy makers are currently faced with the challenge of designing and implementing strategies to maintain soil
fertility and avoid off-site effects.
The highest plant productivity was obtained with vermicompost and synthetic fertilizers, with no significant difference between these two treatments. Chemical fertilization,
however, is the least effective practice based on the amount of nutrients leached from the soil (about 38% of N and 22% of K, compared to less than 10 and 5% of N and K
with organic amendments). P leaching was not influenced by the fertilizer treatments. In conclusion, vermicompost
does appear to be a relevant alternative to chemical fertilizers because it leads to similar enhancements in plant growth, at the same time as increasing soil quality and
decreasing nutrient leaching.
Do Compost and Vermicompost Improve Macronutrient Retention and Plant Growth in Degraded Tropical Soils?
Compost Science & Utilization, (2011), Vol. 19, No. 1, 15-24EP. Jouquet , E. Bloquel , T. Thu Doan, M. Ricoy , D. Orange , C. Rumpel and T.
Tran Duc
The aim of this study was to determine the effect of organic substrate
amendments on soil properties, nutrient leaching and the growth of Ipomea
aquatica in an acidic degraded soil from northern Vietnam. Plants were grown in
an Acrisol in buckets under natural weather conditions for two months. The same amount of nutrients was applied
either in a purely synthetic form (mineral fertilizers) or as two alternative organic substrates (three month old compost or vermicompost from buffalo dung) plus
additional amounts of synthetic mineral nutrients to ensure the same quantity of NPK. The influence of these respective
substrates on the soil’s physical and chemical properties as well as plant
growth was examined. Both compost and vermicompost led to an
improvement in soil properties with an increase in the pH, soil organic matter and nutrient content, compared to soil
fertilized with synthetic mineral products.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002149.html ….. Diunduh 22/4/2012
Increased recycling of organic wastes has raised concern about the quality of compost end products. In addition to the limit values for heavy metals and
impurities including weeds and pathogens, the quality criteria for compost products should also include
criteria for maturity. There is a tremendous number of maturity assays, developed earlier by several
authors, and recommended to be used to evaluate maturity of composts.
Eleven plants composting sewage sludge, source-separated biowaste, manure or a combination of these raw materials were sampled after 1-3 weeks of composting and when the compost was considered “ready for use”. Chemical and physical analyses were considered useful as additional information when evaluating maturity especially
when the results were not conclusively clear. This fast and easy-to-use test scheme was designed especially for the composting plant operators and official laboratories
responsible for evaluating compost quality.
Maturity Tests for Composts — Verification of a Test Scheme for Assessing Maturity
Compost Science & Utilization, (2010), Vol. 18, No. 3, 174-183M. Itävaara , M. Vikman , Maunuksela Liisa and A. Vuorinen
Because no such single test alone reliably demonstrates the complex properties occurring
during maturization of compost, we developed a fast
and easy-to-use two-phase test scheme for the
assessment of maturity. In the first phase the degradation
phase e.g. stability of compost samples is evaluated by using a carbon dioxide evolution test
and/or determination of the NO3-N/NH4-N ratio by simple
test strips. In the second phase, the toxicity of the
compost is evaluated by a plant growth test, germination
tests and/or the Flash bioluminescence test.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002147.html….. Diunduh 22/4/2012
The aim of the work was to compare production of N2O during
composting with different temperature regimes, different aeration intensity and different
input mixture.
The mixture with urea additive showed high N2O production when kept under low temperature; when the same mixture was kept in higher
temperature, production of N2O was 3 fold lower. However, the mixture without urea addition kept in high temperature shows almost no N2O
production. Production of N2O was highest when nitrates concentration increased. Production of N2O is perhaps a by-product of nitrification, but
also other pathways may contribute.
The Role of Aeration Intensity, Temperature Regimes And Composting Mixture on Gaseous Emission During Composting
Compost Science & Utilization, (2010), Vol. 18, No. 3, 194-200Jan Habart , Pavel Tlustos, Ales Hanc, Pavel Svehla, Jaroslav Vána, Petr Tluka and
Frantisek Jelínek
Two different mixtures of organic material with three levels of
aeration underwent the composting process in two temperature
regimes. Mixture A contained woodchips, separated pig slurry,
fresh grass and tree leaves. Mixture B contained woodchips, tree leaves, grass and urea to
optimize C:N ratio. This experiment was carried out in specially
designed 70 liter fermentors. Oxygen and nitrous oxide were monitored in the exhaust air as
well as pH, NO3- and NH4+ and temperature of solid material.
Sumber: http://www.jgpress.com/compostscience/archives/_free/002489.html….. Diunduh 22/4/2012
Wet olive husks represent an environmental problem in
Mediterranean areas but also a potential resource as recyclable organic
matter.
At the beginning of the composting process, protease and dehydrogenase activity, along with the microbial respiration, were higher in the piles with the starter, demonstrating a higher microbial activity in comparison with
the piles without the starter. At the end of the process, the compost with the starter showed a deeper humification and a lower content of total organic carbon with respect to
the compost without the starter, indicating a higher level of biodegradation and organic matter evolution.
The main outcome of this research includes the possibility to: (a) detoxify and de-odorize a bad-smelling waste into an hygienically safe product; (b) produce a green, mature, humified compost useful to restore soil fertility
and texture in intensive and organic agriculture.
Composting Wet Olive Husks with a Starter Based on Oil-Depleted Husks Enhances Compost Humification
Compost Science & Utilization, (2011), Vol. 19, No. 3, 182-188M.C. Echeverria, R. Cardelli, S. Bedini, M. Agnolucci, C. Cristani, A. Saviozzi and M.
Nuti
In the present work, we describe the composting of
wet olive husks, using mechanically turned piles without forced ventilation, carried out to study the
effects of partially composted oil-depleted
husks as a starter for wet husks degradation.
Sumber: http://www.jgpress.com/compostscience/archives/_free/000863.html….. Diunduh 22/4/2012
Six different composts, four of them produced from oil palm residues and
two commercial composts, were studied for their stability and quality.
Composts of oil palm (Elaeis guineesis) trunk and oil palm empty fruit bunch treated with N and P showed good stability and higher quality as compared to other composts. Their C/N ratios were the lowest (14-18) but their pH values were
comparatively low (4.6-6.4). They had a good amount of total N (0.95-1.84%) with higher nitrate than ammonium nitrogen. The specific respiration rates were very low (0.25-0.63) which is an indication that these two composts are stable. Plant growth
test supported conclusions based on the microbiological tests. Their properties were considered as suitable for planting media application. Compost quality can be further improved by adding bunch ash, which has high values of pH and is also a by-product
from the oil palm industry.
The applied nitrogen mineralization index could not be used with all kinds of composts as stability index. Both of the commercial composts showed high C/N ratios (34-68)
and very low values of total and mineral nitrogen compared to oil palm residues composts. They were considered having low nutritional value and not recommended
for planting media application.
Amelioration of Composting Process by FertilizersCompost Science & Utilization, (2004), Vol. 12, No. 1, 80-85
Wan Rasidah Kadir , Rozita Ahmad , Hoi Why Kong and Ognian Stoyanov Kostov
The composts were analyzed for their total C, total N, C/N ratio, mineral N, nitrogen
mineralization index, CO2 production,
biomass C, specific respiration rate,
germination rate, pH values and plant growth index.
Sumber: http://www.jgpress.com/compostscience/archives/_free/000865.html ….. Diunduh 22/4/2012
Compost water extracts (compost teas) are gaining popularity among organic
growers, largely because of their disease suppressive activity when applied to
foliage or soil.
Using disease outbreak strains marked with green fluorescent protein (GFP) and spontaneous antibiotic-resistance, we found that regrowth of
Salmonella enterica serovar Thompson and Escherichia coli O157:H7 was positively correlated with molasses concentration.
For Salmonella, regrowth was also dependent on the type of starter compost material used. Salmonella populations increased from 1 at time 0
to over 1000 CFU ml-1 in dairy manure compost tea with 1% molasses, and from 1 at time 0 to over 350,000 CFU ml-1 in chicken manure
compost tea by 72 h. E. coli populations increased from 1 at time 0 to approximately 1000 CFU ml-1 in both types of tea by 72 h. Pathogen regrowth did not occur when
molasses was eliminated or kept to 0.2 %.
EFFECT OF MOLASSES ON REGROWTH OF E. COLI O157:H7 AND SALMONELLA IN COMPOST TEAS
Compost Science & Utilization, (2004), Vol. 12, No. 1, 93-96Brion Duffy , Chester Sarreal , Subbarao Ravva and Larry Stanker
Production methods often include addition of
supplemental constituents, particularly molasses, to stimulate plant-beneficial microbial populations. We have found that molasses amendments also favor
regrowth of human pathogenic bacteria, raising public health concerns about
potential contamination of treated crops, particularly produce intended for fresh
consumption.
Sumber: http://www.jgpress.com/compostscience/archives/_free/000853.html….. Diunduh 22/4/2012
Compost is a main source of organic matter (OM) and of
nitrogen for organic farming in arid and semiarid regions.
The resulting composts contained 2.63%, 2.84% and 2.39% N for the GM-SCM, OP-SCM and WS-SCM, respectively. Values of N loss from the raw mixtures were 18%, 5% and 2% for the three compost types,
respectively. OM values were 70%, 57% and 53% for the three compost types, respectively.
Nutritional contribution of the composts was assessed using cherry tomato as a test plant, growing in the composts as growing media. Peat moss served as a control medium. The media were either unfertilized or
fertilized with guano.
Plant responses suggest that growth is mainly affected by nitrogen availability while flower production and fruit set is also affected by
potassium availability. It was found that fertilization was not necessary for at least 2 months after planting for OP-SCM and WS-SCM.
Organic Matter and Nitrogen Conservation in Manure Compost for Organic Agriculture
Compost Science & Utilization, (2004), Vol. 12, No. 1, 6-10Michael Raviv, Shlomit Medina, Arkady Krasnovsky and Hammam Ziadna
An effort has been made to reduce nitrogen loss during
composting of separated cow manure (SCM) using high
C/N additives - wheat straw, (WS), grape marc (GM) and slightly acidic additive such
as orange peels (OP).
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18466954 ….. Diunduh 28/4/2012
The aim of this work was to study the viability of recycling the solid wastes generated by the winery and distillery
industry by means of co-composting with animal manures, as well as to evaluate the
quality of the composts obtained.
Organic matter losses followed first-order kinetics equation in both piles, the highest organic matter mineralisation rate being observed with exhausted grape marc and cow
manure. On the other hand, the mixture with the lowest C/N ratio, using exhausted grape marc and poultry manure, showed the highest initial ammonium contents,
probably due to the higher and more labile N content of poultry manure. The increase in the cation exchange capacity revealed the organic matter humification during
composting. In contrast, other humification parameters, such as the humification ratio and the humification index, did not show the expected evolution and, thus, could not
be used to assess compost maturity. Composting produced a degradation of the phytotoxic compounds, such as
polyphenols, to give composts without a phytotoxic character. Therefore, composting can be considered as an efficient treatment to recycle this type of wastes, due to composts presented a stable and humified organic matter and without phytotoxic
effects, which makes them suitable for their agronomic use.
Chemosphere. 2008 Jun;72(4):551-7. Epub 2008 May 7.Co-composting of distillery wastes with animal manures: carbon and nitrogen
transformations in the evaluation of compost stability.Bustamante MA, Paredes C, Marhuenda-Egea FC, Pérez-Espinosa A, Bernal MP,
Moral R.
Two piles, using exhausted grape marc and cattle manure or poultry manure, respectively (at ratios, on
a fresh weight basis, of 70:30), were composted by the Rutgers static pile composting system.
Throughout the composting process, a number of parameters
were monitored, such as pH, electrical conductivity, organic matter, water-soluble carbon,
water-soluble polyphenols, different forms of nitrogen (organic nitrogen, ammonium and nitrate)
and humification indices (humification ratio, humification
index, percentage of humic acid-like C, polymerisation ratio and
cation exchange capacity), as well as the germination index.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18715609 ….. Diunduh 28/4/2012
In this work the carbon biodegradation of exhausted grape marc (EGM)
combined with other organic wastes using the turned pile composting
system was studied.
Regarding to the rate constants of the composting processes they were increased from 0.033d(-1), the value obtained when EGM was composted alone, to 0.040 and 0.044d(-1) when MSW and GS were added, respectively as co-substrates. However,
the addition of CMS reduced the rate constant.
About the biodegradable carbon fractions, it was observed that the co-composting reduced significantly the remanent carbon concentration after composting in all the piles whilst increased the readily biodegradable carbon fractions from 35, the value
obtained when EGM was composted alone, to 50 and 60%, respectively when MSW or GS were added.
As regards the temperature profiles, only Piles 1 and 4 achieved thermal hygienization values and about the nitrogen losses, the lowest percentage of nitrogen loss took place when GS were added, because of its optimum pH and C/N initial ratio.
Thus, though any of these wastes could be used for co-composting with EGM, the use of GS as co-substrate and bulking agent for the co-composting process of EGM
was recommended.
Chemosphere. 2008 Oct;73(5):670-7. Epub 2008 Aug 19.Evaluation of carbon degradation during co-composting of exhausted grape
marc with different biowastes.Fernández FJ, Sánchez-Arias V, Villaseñor J, Rodríguez L.
Four different piles were made of EGM in Pile 1, EGM mixed with cow manure and straw (CMS) in
Pile 2, EGM mixed with municipal solid waste (MSW) in Pile 3 and
EGM mixed with grape stalks (GS) in Pile 4.
The results obtained were modelled to determine the main
kinetic and stoichiometric parameters.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19244411 ….. Diunduh 28/4/2012
To study the feasibility of co-composting poultry manure with low quantities of high-value, carbon-rich
materials experiments to characterize three pilot-scale piles were carried
out.
Pile 1 presented the highest losses of organic matter and nitrogen contents (> or = 92.9% and 92.0%, respectively). Although a
thermophilic phase (temperature > 40 degrees C) was not verified for this pile, the final compost was stable (class IV) and free of pathogen
indicator micro-organisms but it was the most phytotoxic, and presented a humic and fulvic acids ratio (HA/FA) that was less than 1. In contrast, piles 2 and 3 sustained thermophilic phases and produced stable (class
V) and mature (HA/FA > 1) composts.
Pile 2 showed the lowest loss in nitrogen content (88.9%) and produced the final compost with the highest C/N ratio (14.7) and the lowest value
of electrical conductivity (3.9 mS cm(-1)).
This study showed that it is possible to reduce the costs of poultry manure composting, namely the costs associated with the use of carbon-rich materials, given that the final co-composts presented
parameters within the range of those recommended by the Second Draft Proposal for compost quality.
Waste Manag Res. 2009 Mar;27(2):119-28.Co-composting of poultry manure with low quantities of carbon-rich materials.
Silva ME, Lemos LT, Cunha-Queda AC, Nunes OC.
The piles comprised poultry manure (pile 1), poultry
manure and straw (pile 2) and poultry manure and
sawdust (pile 3), using wood chips as bulking agent.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19450961 ….. Diunduh 28/4/2012
Rice hulls and sawdust are two common C-rich wastes derived from rice and timber agro-industries in subtropical NE Argentina. An
alternative to the current management of these wastes (from bedding to uncontrolled burning)
is composting. However, given their C-rich nature and high C/N ratio, adequate
composting requires mixing with a N-rich waste, such as poultry manure.
Different indicators of compost stability and quality were measured. Thermophilic phase was shorter for piles with rice hulls than for piles with
sawdust (60 days vs. 105 days). Time required for stability was similar for both C-rich wastes (about 180
days). Characteristics of final composts were: pH 5.8-7.2, electrical conductivity 2.5-3.3 mS/cm, organic C 20-26%, total N 2.2-2.9%, lignin 19-22%, total Ca 18-24 g/kg, and extractable P 6-8 g/kg, the latter representing 60% of
total P. Nitrogen conservation was high in all piles, especially in the one
containing both C-rich wastes. Piles with sawdust were characterized by high total and available N, while
piles with only rice hulls had higher Si, K and pH. Extractable P was higher in 1:1 piles, and organic C in 2:1 piles
Waste Manag. 2009 Sep;29(9):2446-53. Epub 2009 May 17.Co-composting rice hulls and/or sawdust with poultry manure in NE
Argentina.Leconte MC, Mazzarino MJ, Satti P, Iglesias MC, Laos F.
The effect of different proportions of poultry
manure, rice hulls and/or sawdust on composting
efficiency and final compost quality was
studied. Five piles were prepared with a 2:1 and 1:1 ratio of sawdust or rice hulls to
poultry manure, and 1:1:1 of all three materials (V/V).
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19244411 ….. Diunduh 28/4/2012
To study the feasibility of co-composting poultry manure with low quantities of high-value, carbon-rich
materials experiments to characterize three pilot-scale piles were carried out.
Pile 1 presented the highest losses of organic matter and nitrogen contents (> or = 92.9% and 92.0%, respectively). Although a
thermophilic phase (temperature > 40 degrees C) was not verified for this pile, the final compost was stable (class IV) and free of pathogen
indicator micro-organisms but it was the most phytotoxic, and presented a humic and fulvic acids ratio (HA/FA) that was less than 1. In contrast, piles 2 and 3 sustained thermophilic phases and produced stable (class
V) and mature (HA/FA > 1) composts.
Pile 2 showed the lowest loss in nitrogen content (88.9%) and produced the final compost with the highest C/N ratio (14.7) and the lowest value
of electrical conductivity (3.9 mS cm(-1)).
This study showed that it is possible to reduce the costs of poultry manure composting, namely the costs associated with the use of carbon-rich materials, given that the final co-composts presented
parameters within the range of those recommended by the Second Draft Proposal for compost quality.
Waste Manag Res. 2009 Mar;27(2):119-28.Co-composting of poultry manure with low quantities of carbon-rich materials.
Silva ME, Lemos LT, Cunha-Queda AC, Nunes OC.
The piles comprised poultry manure (pile 1), poultry
manure and straw (pile 2) and poultry manure and
sawdust (pile 3), using wood chips as bulking agent.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/19796932 ….. Diunduh 28/4/2012
The aim of this study was to evaluate the use of biochar (produced by slow
pyrolysis of Eucalyptus grandis biomass) as bulking agent for the composting of poultry manure.
The organic matter of the poultry manure-biochar mixture was characterised by a high polymerisation degree of the humic-like
substances, with a relative high proportion of humic acids in relation to fulvic acids.
At the end of the composting process, the humic acid fraction represented more than 90% of the alkali extractable fraction, reflecting the intense
humification of this material.
Enrichment of poultry manure with biochar reduced the losses of nitrogen in the mature composts, although the use of sawdust would be more efficient in preserving the organic matter and nitrogen in the mature
compost.
Bioresour Technol. 2010 Feb;101(4):1239-46. Epub 2009 Sep 30.Use of biochar as bulking agent for the composting of poultry
manure: effect on organic matter degradation and humification.Dias BO, Silva CA, Higashikawa FS, Roig A, Sánchez-Monedero MA.
Three composting mixtures were prepared by the turned-pile system by mixing poultry manure with different organic wastes used as bulking agent
(biochar, coffee husk and sawdust) in a proportion of 1:1
(fresh weight). Despite the inert nature of biochar, the composting
mixture prepared with biochar underwent an organic matter
degradation of 70% of the initial content.
Sumber: http://www.ncbi.nlm.nih.gov/pubmed/18692391 ….. Diunduh 28/4/2012
The aim of this study was to document whether addition of lime or increased
amount of bulking agent would ensure, efficiently, a predictable composting
process in acidic SSOW applicable in full scale plants.
Both strategies are considered efficient in establishing desired microbial composting processes of acid household waste.
Reduction in the content of different organic acids and loss on ignition were higher when more bulking agent was used
compared with adding 5% lime to the acidic SSOW.
Respiration was completely repressed in samples with 10% lime, where pH remained high. In addition fat and protein seem to
degrade faster with increasing amount of bulking agent.
Bioresour Technol. 2009 Jan;100(2):521-6. Epub 2008 Aug 8.Strategies to reduce short-chain organic acids and synchronously
establish high-rate composting in acidic household waste.Bergersen O, Bøen AS, Sørheim R.
The results show that both lime addition and
increasing the amount of bulking agent relative to
waste support the development of high-rate
respiration in composting.
