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Preliminary study of diesel biodegradation mechanism in the food waste composting process

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May 25-26, 2012

Li-Hsien Chen1, Guan-Yu Chen1, Guo-Huei Wang1, Der-Shyan Sheu2, Chitsan Lin1

1 Department of Marine Environmental Engineering, National Kaohsiung Marine University.2 Department of Marine Biotechnology, National Kaohsiung Marine University.

Email: acermarcor@yahoo.com.tw

2012 International Conference on Environmental Quality Concern, Control and Conservation (EQC 2012)

D e p a r t m e n t o f M a r i n e E n v i r o n m e n t a l E n g i n e e r i n g , N a t i o n a l K a o h s i u n g M a r i n e U n i v e r s i t y

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Research Background And Motivation

Materials And Methods

Research Purposes

Conclusions

Results And Discussion

OUTLINE

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Research Background

Source: Taiwan EPA (http://edw.epa.gov.tw/querySoilSite.aspx)

Pollution characteristicsNumber of

remediation sites

Soil and groundwater Heavy metal contaminated sites

Soil and groundwater organic contaminated sites

Soil and groundwater Heavy metal and organic contaminated

sites

(27 sites)

(79 sites)

(5 sites)

Total remediation sites111 sites (67 oil-related remediation

sites)　

Oil pollution is a serious environmental problem in the past decades. According to the Taiwan EPA, there are 67 documented oil-related remediation sites in Kaohsiung.

Lin et al. (2012) reported an innovative mineral oil treatment technology. The other report that utilizing food waste thermophilic composting process to degrade 7,000 mg/kg of diesel contaminated soil in a scale of 10 tons. the diesel removal rate reached 90 % on Day 54.

The method has the following advantages:

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low costs

less secondary pollution

can be backfilled to the site

Rich nutrients

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2

3

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Food waste composting processes to degrade diesel will produce the intermediate VOCs (Volatile Organic Compounds), while VOCs with the composting process, resulting in different types of compounds.

However, we still don’t know mechanism. If we know the mechanism, then we can control the VOCs from compost.

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Research Motivation

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This study was divided into two parts:

（ A ） The VOCs of food waste composting process by

GC / MSD analysisUse of the airbags sampling with GC / MS analysis.

Features: analysis of 101 kinds of voc compounds at one

time.

（ B ） Exploring the diesel oil biodegradation

mechanism in the food waste composting

process. 。

Research Purposes

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MATERIALS AND METHODS

Experimental Framework

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Food waste70kg

sawdust 15kg

mature compost 15kg

Compost pile

VOC sample collection

Analysis

Discussion

Moisture content

pH

Temperature

Basic parameters monitoring

Add 1kg diesel

Control pile

Experimental pile

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Compost Operational Procedures

Food waste weighing 70 kg was shredded to 1-cm particles. After mixed with 15 kg of sawdust (15%, w/w) and 15 kg of mature compost (15%, w/w).Water was added to maintain 50-60% moisture content. Temperature, moisture content, and pH were monitored during composting process.

Collection pool

Crusher Machine

Mixed

Sampling airbags

Soil Gas Sampling Design

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Compost,Sampling tubePump

Negative pressure box

•The day before sampling, buried sampling tube into compost。•Making the vacuum pump turns box into negative-pressure situation.•The compost gas (VOCs) was collected form outside to inside fill the sampling bag.

Sampling setup

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Analysis Equipment

Agilent 7890 GC

Agilent 5975N MSD

Entech 7100

Glass Bead Cryo

Tenax-TA Trap

Cryo Focus

Airbags

Entech 7100

Entech 7032Auto sample

Analytical instruments

Entech 7100Cryogenic preconcentration

Agilent 7890 GAS Chromatography (GC)

Agilent 5975 MSD

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RESULTS AND DISCUSSION

Alkanes Cycloalkanes Aromatics Alkenes Butane

Isopentane2,3-Dimethylpentane

2-Methylpentane3-Methylpentane

Hexane2,4-Dimethylpentane

2-Methylhexane2,3-Dimethylpentane

3-Methylhexane2,2,4-trimethylPentane

Heptane2-Methylheptane3-Methylheptane

n-OctaneNonane

n-Decanen-UndecaneDodecane

cyclohexaneMethyl-cyclohexane

BenzeneToluene

Ethylbenzenem,p-Xylene

Styreneo-Xylene

Isopropylbenzenen-propylbenzenem-Ethyltoluenep-Ethyltoluene

1,3,5-trimethyl-Benzeneo-Ethyltoluene

1,2,4-trimethylbenzene1,2,3-trimethylbenzene

m-Dieyhylbenzenep-Diethylbenzene

Propene1-Butene

Trans-2-ButeneCis-2-Butene

Isoprene1-Hexene

Sulfur Alcohols Carbonate ester Aldehydes Dimethyl sulfide

Dimethyl disulfideMethanethiolEthyl Alcohol

2-Butanol1-propanol-2-methyl1-Butaol,3-methyl

Acetic acid, methyl eaterEthyl acetate

Methyl propionaten-propyl acetate

Propanoic acid, ethyl esterButanoic acid, methyl

ester1-Butaol,3-methyl acetate

Propanal 2 methyl-Butannal,3-methylButanal,2-methyl-

Ketones BIO-VOC Amines  2-Propanone(Acetone)

2-Butanone(MEK)2,3-Butanedione

1R-.alpha.-pinene.beta.-pineneD-Limonene

Trimethylamine  15

The all VOCs of food waste composting processes to degrade diesel table

Total VOCs change during the compost process

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0 2 4 6 8 10 120

100

200

300

400

500

600

Time （ days ）

Tot

al V

OC

s con

c. （

ppm

）

Temperature Rising Stage

Thermophilic Stage Temperature Recovering Stage

The initial of the composting produces the highest VOCs conc. , after rising stage shows a slow downward trend.

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The VOCs of scale during Temperature Rising and Thermophilic Stage

alkanes, 9.47% (5)

(4) (3)

alcohols, 21.34%

carbon-ate ester, 59.70%

(2) (1)

(1) Bio-voc(2) Ketones(3) Aromatics(4) Cycloalkanes(5) Alkene

Temperature Rising Stage

(4) (3) (2)

alcohols, 23.74%

(1) (6)

(5)

aldehydes, 5.95%

ketones, 25.03%

BIO-VOC, 27.26%

(1) carbonate ester(2) aromatics(3) alkene

Thermophilic Stage

(4) Alkanes(5) Amines(6) Sulfur

Alkanes Alkene Cycloalkanes Aromatics Alcohols Carbonate ester

Sulfur Amines Aldehydes Ketones BIO-VOC

Rising 9.47 0.35 1.47 1.63 21.34 59.70 0.75 5.01

Therm 4.67 1.75 0.02 0.47 23.74 4.33 4.65 2.14 5.95 25.03 27.26

0 2 4 6 8 10 120

50

100BIO VOC

控制組 添加柴油

0 2 4 6 8 10 120

200

400carbonate ester

010203040

Alkanes

0102030

Sulfur

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The VOCs groups changes of food waste composting processes to degrade diesel

Tota

l Voc

s co

nc.

（ppm

）

Time （ day ）Time （ day ）

Rising RisingThermophilic Stage

Thermophilic Stage

0

2

4

6

Alkenes

0246

Cycloalkanes

0

5

10 Aromatics

0204060

Ketones

0

100

200 Alcohols

0102030

Aldehydes

0

5

10Amines

After 1 day composting, the compost gas consists of alcohols and carbonate ester. The contribution of alcohols and carbonate ester may be from the fermentation of more biodegradable food waste or alkanes in the diesel.

On the 3th day, the compost gas emerges of thermophilic fermentation products these include ketones , aldehydes and sulfides. They may be from the alcohols and carbonate ester.

During the diesel composting process (day 0 to day 8), bio-VOCs were observed all the time; these include 1R-.alpha.-pinene, beta.-pinene and D-limonene.

The composition of initial compost gases includes alkanes, alkene, naphthenic class, and the aromatics. The main source of VOCs at this stage is from low molecule weight compounds within the diesel constituents.

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The VOCs compounds changes of food waste composting processes to degrade diesel

0

1

2

3

4

5

6

7

8

9

10

n-OctaneMethyl-cyclohex-ane1-ButeneToluene

Tot

al V

ocs c

onc.

（pp

m）

0 2 4 6 8 10 120

50

100

150

200

250

300

Ethyl acetateEthyl Alcohol

0 2 4 6 8 10 120

102030405060708090

Butannal,3-methyl

Time （ days ）

1. The composition of initial compounds is n-Octane、Methyl-cyclohexane and Toluene

2. Dimethyl sulfide is the most common compounds in the composting process.

3. After 1 day composting, the compost gas consists of Ethyl acetate and Ethyl alcohol.

4. the compost gas emerges of thermophilic fermentation products these include Butannal, 3-methyl、 2-Butanone.

5. D-Limonene is the highest concentration of compound of BIO-VOC

Rising Thermophilic Stage Rising Thermophilic Stage

According to the above finding, we assume the mechanism as follows.

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The preliminary mechanism of diesel biodegradation

TPH Alkane Alcohol Ketone / Aldehyde Carboxylic acid

Sulfur Ester

Naphthenic class Alkene

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CONCLUSIONS

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There were 11 groups of VOC monitored in the diesel degradation process, consisting of alkanes, cycloalkanes, aromatics, alkenes, alcohols, carbonate ester, ketones, aldehydes, sulfur compounds, amines, and bio-VOC . The composition of initial compost gases includes alkanes (62.76%), alkene (8.41%), naphthenic class (13.86%), and the aromatics (4.78%). The main source of VOCs at this stage is from low molecule weight compounds within the diesel constituents. After 1 day composting, the compost gas consists of alcohols (21.34%) and carbonate ester (59.70%). The contribution of alcohols and carbonate ester may be from the fermentation of more biodegradable food waste or alkanes in the diesel.

(1)

(2)

(3)

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On the 3th day, the compost gas emerges of thermophilic fermentation products these include ketones (25.03%), aldehydes (5.95%) and sulfides (4.65%).

During the diesel composting process (day 0 to day 8), BIO-VOCs were observed all the time; these include 1R-.alpha.-pinene, beta.-pinene and D-limonene.

During the entire diesel composting process, we also identified many organic acids which were assumes as the end products of aerobic biodegradation.

(4)

(5)

(6)