Upload
amin-mojiri
View
222
Download
0
Embed Size (px)
Citation preview
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
1/12
International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014Available online at http://www.ijsrpub.com/ijsrk
ISSN: 2322-4541; 2014; Author(s) retain the copyright of this articlehttp://dx.doi.org/10.12983/ijsrk-2014-p0497-0508
497
Review Paper
Treatment of Leachate by Electrocoagulation Technique Using Iron And HybridElectrodes
Mostafa Mohammadizaroun, Mohd Suffian Yusoff*
School of Civil Engineering, Engineering Campus, University Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia*Corresponding Author: [email protected]
Received 28 September 2014; Accepted 11 November 2014
Abstract. The most techniques for treating leachate and wastewater are physical, chemical, biological, advanced oxidation andelectrochemical techniques. Developed oxidation techniques lead to high treatment cost and mostly are used in purifying gradewaters. Among these techniques, the chemical coagulation technique not only is a slow process, but also produces a largeamount of sludge. Electrocoagulation has been used for treating industrial effluent and leachate as a potential technique
because of its compatibility and adaptability with environment. In this technique, a direct current source between metalelectrodes plunged in the effluent is used to dissolve the electrode plates into the effluent. The metal ions with appropriate pHcan create various types of coagulated species and metal hydroxides that in turn cause to rolling up and destabilizing theelements, or catalyzing and absorbing the dissolved pollutants. Therefore, the purpose of the current study is to examine the
potentials of electrocoagulation in treating the leachate and wastewater by treating the heavy metals and their colour andsalinity. Furthermore, the present study aims to investigate the electrocoagulation, electrochemical technologies and theirdesign and application in treating the leachate, water, and wastewater. This work mostly dealt with the electrocoagulation
(EC), electrodeposition, electroflotation (EF), and electrooxidation. It was shown that Electrodeposition is efficient in treatingthe wastewater stream and removing heavy metals. In addition, electrocoagulation was used for treating wastewater and producing clean water as well. It was also found that using aluminum, iron or the hybrid Al/Fe electrodes are more applicable.
Keyword: Electrocoagulation, Treatment, Leachate, Wastewater, Iron and Aluminum Electrode, Hydride electrode
1. INTRODUCTION
Electrocoagulation is an electrochemical method thatis employed for both wastewater and surface watertreatment. In this method, sacrificial anodes areoxidized and active coagulant precursors, such asaluminum or iron cations, are released into liquid.During this process, additional electrolytic reactions
produce gas at the cathode, which is usually in theform of hydrogen bubbles (Holt et al., 2005) .Drinking water that is polluted by heavy metals isdangerous for human health. One of the techniquesthat are used for purifying wastewater isElectrocoagulation. This technology employselectrolytic oxidation of anode materials and in-situgeneration of coagulation (Wan et al., 2011) . The
purpose of using electrocoagulation (EC) is removingvarious types of pollutants such as heavy metal ions
from water and wastewater effluents (Shafaei et al.,2010) . .electrocoagulation (EC) has attracted the attention
of the environmental sectors largely as an efficientway to treat different types of water and wastewater
during the last two decades, and especially during thelast few years. The purpose of the present work is tostudy some related researches that were conductedmainly on the widespread use of practicalelectrocoagulation in treating different types of waterand wastewater during 2008-2014.
Due to the large amount of wastewater comingfrom industry and its variety, its purification is still anoteworthy environmental problem in the world (Zodiet al., 2009) . Some of these wastewater types canshow evidence of high chemical oxygen demand(COD), dark color, and strong bad smell. Thus it isessential to treat the sewerage before dischargingthem into the environment and water sources. For this
purpose, electrocoagulation has been employed to purify different types of wastewater generated byindustry section in recent years (Khemis et al., 2006) .Accordingly, EC method has absorb the interest of
many researchers for being applied to treat the waterand wastewater. It is one of the recently developedwater technologies that has been used successfully in
purifying different types of wastewaters (Tchamangoet al., 2010) .
mailto:[email protected]:[email protected]:[email protected]:[email protected]8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
2/12
Mohammadizaroun and YusoffTreatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
498
The applications of Electrocoagulation (EC)method in this study has been classified into ninecategories including: tannery, pulp and paper industrywastewater, textile and colored wastewater, foodindustry wastewater, oily wastewater, laundry anddairy wastewater, other types of industrial wastewater,surface and model water and wastewater that containheavy metals, cyanide, nutrients, and other elements,and ions. Moreover, the current study aims to outlinethe best conditions in the process of treatment such astreatment time, existing density and pH as well as thehigh level of efficiency in removing pollutants whileapplying the EC under discussion (Kuokkanen et al.,2013) .
One of the appropriate ways for purifying dairywaste is applying Electrocoagulation with aluminum
anode because there is acceptable reduction ofdifferent parameters such as turbidity, total phosphorous, and nitrogens (Tchamango et al., 2010) .In addition, this process requires fewer reagents, i.e.the quantity of aluminum that is liquefied in this
process is lower than the amount of aluminum saltdissolved in chemical coagulation (Tchamango et al.,2010) .
By using Electrocoagulation (EC), which is a typeof cheap and green method for removing heavy metalsfrom wastewater, some chromium can be removedfrom industrial effluents, namely metallurgy,
electroplating, leather tanning, chemicalcatalysts, pigments, corrosion inhibitors and printing inks(Mouedhen et al., 2009) .
2. LEACHATE
Leachate is a very complex liquid with highconcentration of pollution that makes its treatmentvery hard and providing the removal standards isdifficult. Among other types of wastewaters, leachateis the most difficult one to treat because it containscomplex structure that is produced within a landfill.Accordingly, the variety types of pre-treatment andmixed methods of treatment were used to treatleachate (Welander et al., 1998) .
2. ELECTROCOAGULATION REACTORS FORHEAVY METALS REMOVAL
According to the recent studies on the reactor designsand functions, it is found that the easiest way and low-cost facility for treating localized water could be a setof reactor systems that has vertical plate electrodes. Indesigning the reactor being made of electrolytic gasflotation, the separation of the aggregated pollutants inelectrodes is the primary goal (Holt et al., 2005) .
Electrocoagulation (EC) has been introduced formore than one century. Electrocoagulation with
aluminum and iron has already been awarded in theUS in 1909. Due to its applicability, EC has beeninvestigated broadly in the US and Soviet Union(former USSR) during the second half of 20 th century.However, despite the extensive studies in those times,its broad feasibility in treating water was not foundclearly. Perhaps the main reason was the high costs ofelectricity and investment in those days (Chen, 2004) .
Electrocoagulation (EC) has been investigated andapplied for purifying the wastewater by manyresearchers previously and the results show that thereare several differences in the processes of chemicalcoagulation. The review of literature demonstratesthat Electrocoagulation is a useful process in treatingdifferent wastes such as soluble oils, liquid generated
by food, industrial materials, and fibers and effluents
come from the paper industry (Carmona et al., 2006) .EC is an electrochemical method used in purifying the polluted water by which sacrificial anodes areoxidized so that active coagulant precursors such asaluminum or iron cations could be released intoliquid. Additional electrolytic reactions produce gas atthe cathode, which is usually in the form of hydrogen
bubbles (Holt et al., 2005) . An electrocoagulationreactor, essentially, is an electrochemical cell bywhich a sacrificial metal anode, which is occasionallymade of iron and usually of aluminum, is utilized tomeasure the amount of polluted water by suing a
coagulating agent (Holt, 2006) .Electrocoagulation (EC) application is considered
as a conventional development technology with possibility to improve the space-time efficiency. It hasalso been used to produce water or purify wastewater.Using aluminum, iron, or the hybrid Al/Fe electrodesare found to be more applicable as well (Chen, 2004) .Despite the fact that electrocoagulation technique has
been introduced for more than one century, itsapplication efficiency in purifying wastewater hasfound recently. The design of an industrial plant andan electrocoagulation cell are mostly based on
previous empirical studies that had little attention tothe electrocoagulation mechanism (Calvo et al.,2003) . Electrocoagulation (EC) is known as the easyand efficient electrochemical method for treatingdifferent types of water and wastewater (Tezcan et al.,2006) . The characteristics of this technique are: easyin operation, simple equipment, and decreased amountof mud. In this process, the generation of coagulant byelectrolytic oxidation of a proper anode material at a
proper pH leads to unsolved metal hydroxide that laterremoves the various types of contaminant (Adhoumand Monser, 2004) .
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
3/12
International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014
499
2.1. Types of reactors used
As it was referred earlier, according to the previousstudies about reactor designs and functions, it is foundthat the simplest method and low-cost facility for
purifying wastewaters is a set of reactor system whoseintegral characteristic and function is separating theaggregate contaminant by using electrolytic gasflotation (Holt et al., 2005) .
As it was mentioned earlier, all electrocoagulationreactors have electrochemical units. All of thesereactors have an electrode set that is in contact withthe polluted water. One of their specific characteristicsis a coagulant production in situ. A practical probabledifference between the electrodes is required forreleasing the coagulant. The electrochemical half-cell
reactions that occur at each electrode can reduce the potential requirements for electrodes. Each electrodewill differ according to the efficient pH and the grouptype that exists in the system.
2.2. Electrode materials
Different materials could be used as electrodes forelectrocoagulation and electrode material has beenknown to be an important factor influencing the
performance of the electrocoagulation process. AlsoIron and Aluminum or hybrid (Al/Fe) usually used as
electrode in electrocoagulation process (Ratna et al.,2004) . Electrode material is known to be an importantfactor influencing the performance of theelectrocoagulation process. Different materials can beused as electrodes for electrocoagulation. Iron,Aluminum, and hybrid (Al/Fe) are usually used aselectrode in electrocoagulation process as well.
3. EFFECTING OF FACTORS ONELECTROCOAGULATION PROCESSES
3.1. Effect of temperature
According to the findings of studies done on removingwaterborne bacteria from geothermal water, it wasdemonstrated that one of the vital affecting factorsthat has a significant positive effect on the process ofelectroquagulation is temperature (Yilmaz et al.,2008) . Yilmaz et al. (2008) found that, like manyother chemical reactions, temperature helpselectrochemical reaction rate enhances. Theydemonstrated that if the temperature reaches to 40 oC,efficiency of Borne removal increases 12% formingcoagulate of flocked ions on anode surface. Thus theincrease in temperature could not contributed as lineeffect effect factor on the process ofelectroquagulation (Yilmaz et al., 2008) .
In studied range, temperature, in comparison withthe effect of electrode charge per liter and origin pH,was slightly effective in removing natural organicmatter (NOM). In fact, temperature had major effectthrough the various dissolving rate of the electrodes(Vepslinen et al., 2009) 4) In a study done by Kataland Pahlavanzadeh (2011) , Electrocoagulation wasexamined as a possible way to reduce the color,
phenol, and COD pollutants from wastewater of papermill. It was found that efficiencies tend to to constantvalues after 30 minutes of electrocoagulation (Kataland Pahlavanzadeh, 2011) .
3.2. PH effecting
The electrolyte pH plays an important role in the
operation of the electrocoagulation process (Chen etal., 2000) . In order to verify the efficiency oflectrolyte pH on the electro-coagulation effectiveness,many empirical studies have been carried out atdifferent pH and various observations were obtained.The utmost percentage of removal COD was observedat the pH of 7 for mild steel. The increase in theelectrolyte pH more than 7 did not get any upgradingon percentage of removal COD (Kalyani et al., 2009) .This can be justified by the fact that the solvability ofFe(OH) 3 could cause the increase pH value beyonf 7that results in forming the solvable Fe(OH)4, this is
not associated to the reduction of COD (Kobya et al.,2003) . The primary pH at the beginning has asignificant influence on the application ofelectrocoagulation process (Song et al., 2007; Wang etal., 2009) . The findings showed that the increase in
pH could increase the removal efficiency (Akbal andCamc, 2011 ).
5) According to Can et al. (2003) and Daneshvar etal. (2003), one of the significant factors that influencethe performance of electrochemical process is theinitial pH. The efficiency of treatment process wasvery low at both high and low pH (Aoudj et al., 2010) .
3.3. Distance between electrodes
The other important factor that is known to beinfluencing the efficiency of the electrocoagulation
performance is distance between electrodes.
3.4. Effect of current density
According to the findings, it is expected that theincrease amount of existing density will result inincrease of removal efficiency (Akbal and Camc ,2011) . On the other words, the increase in the appliedcurrent density results in an increase in effectivenessof removing heavy metals such as Cr, Cu, Ni, and Crfor the Fe-Fe pairs of electrocoagulation (Akbal and
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
4/12
Mohammadizaroun and YusoffTreatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
500
Camc , 2011) . Many researchers have reported thatthe current density has significant influence on theeffectiveness of process of electrocoagulation. It can
be explained by the fact that the ammount of anodicdissolution increases at the high current densities,which in turn, the increased amount ofhydroxocationic complex leads to increased CODremoval. In addition, the rates of coagulant (flocksstructure) and bubble production can be determined
by the current density applied in the process. This, inturn can impact on the efficiency of the process. Onthe other hand, the increased density of gas bubbleswith the reduced size results in increase in upwardsflux that leads to increased degradation of pollutantsand mud floating (Kobya et al., 2003) .
Holt et al. (2002) states that the coagulant dosage
rate and the bubble production rate, size, and flockgrowth can be determined by current density, which inturn can affect the efficiency of treatment byelectrocoagulation (Holt et al., 2002)
In addition, current density is recognized as asignificant operational factor that affects mechanismdominating the pollutant removal (Holt et al., 2005) .
3.5. Effect of operation time
According to the Faradays law, the factor that canalso affect the efficiency of removing Cr (VI) in the
process of electrocoagulation is the reaction time. Itcan also determine the rate of producing Fe 2+ or Fe 3+ ions from electrodes (Mollah et al., 2004) .
3.6. Effect of conductivity
The results of related studies showed that increasedremoval efficiency is dependent on the increase inconductivity. In addition, the decrease of spendingenergy and electrode results from increasingconductivity (Akbal and Camc, 2011 ).
3.7. Supporting electrolyte concentration
The findings show that the increase in the supportingelectrolyte density results in the increase in the CODremoval efficiency. This is explanable that with the
presence of cholorides in the solution, C12 and OC1are produced. The OC1 is a strong oxidant thatoxidize the organic cells existing in the water.Consequently, not only does the supporting electrolyte
increase the efficiency and productivity of the process, but also it functions as a strong oxidizing factor. Thesimilar result was reported for the percentage ofefficiancy in removing the color (Kalyani et al.,2009) .
4. ADVANTAGES AND DISADVANTAGES OFEC
(1) EC is a simple equipment and easy to work withadequate operational scope that can overcome most ofthe problems that may be encountered during theoperation.
(2) The water after purification are palatable, clear,colorless, and without odor.
(3) The sludge produced during the process is
ready to be set again and easy to be dried out, becausethey mostly contain metallic oxides and hydroxides.(4) The flocs that are produced by EC are similar
to the chemical flocs; however, it is expected to belarger and contain less bound water, be more stableand acide-resistant that can, consequently, beseparated faster by filters.
(5) In comparison with the chemical treatment, EC produces sewage that contains less total dissolvedsolids (TDS) contents. Consequently, if this water isgoing to be reused, the low TDS level requires lowerrecovery cost.
(6) The EC process removes the lower amount ofcolloidal elements, because the used electric field setsthem in faster movement by which the coagulation isfacilitated.
(7) In EC, there is not any problem of neutralizingexcess chemicals as well as the possibility ofsecondary pollution resulted from chemicalsubstances that are added at high density, becauseunlike chemical coagulation of wastewater, EC doesnot use chemicals.
(8) In EC, the bubbles of gas that are producedduring the electrolysis process carry the contaminantto the top of the liquid and from there it can be easilycollected and removed out.
(9) The EC process requires less maintenance because the electrolytic processes in the EC cell arecontrolled electrically with no moving parts.
(10) This technique can be easily applied in ruralareas where even the electricity is not available
because a solar board is attached to it that might besufficient for operating the process.
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
5/12
International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014
501
Fig. 1: bench-scale Electrocoagulation reactor with monopolar electrode in parallel concetion (Pretorius, Johannes et al. 1991)
5. DISADVANTAGES OF EC
(1) The 'sacrificial electrodes' need to be replacedregularly due to oxidation and being dissolved into thewastewater streams.
(2) Using electricity could be expensive in many places.
(3) Sometimes a waterproof oxide film is locatedin the cathode to lessen the possibility of loss ofefficiency of the process.
(4) In this system, a high conductive wastewatersuspension is required.
(5) Sticky hydroxide sometimes tends to bedissolved in some cases (Mollah et al., 2001) .
Mechanism of electrocoagulation techniqueAn electrocoagulation reactor, in the simplest
form, has a monopolar electrode with one anode andone cathode. When the external power source isconnected to it, the anode will be oxidized and flakedelectrochemically, but the cathode remains passive.However, this process is not suitable for wastewater
purification because for this purpose a large surface ofelectrodes is required in order to be able to dissolvethe pollutants. This has been achievable by using cellswith monopolar electrodes that are connected either in
parallel or in series. A simple system ofelectrocoagulation (EC) cell with two anodes and twocathodes connected in parallel is illustrated in Fig. 1.
Fig. 1 shows that it, in essence, is made up of pairsof conductive metal plates that are located betweentwo parallel electrodes and a dc power source. Thisinvestigational system also needs a resistance box tocontrol the present density as well as a multi-meter forreading the existing values. The conductive metal
plates are generally known as 'sacrificial electrodes'.The sacrificial anode reduces the possibility ofdissolution of the anode and lessens the passivation ofthe cathode. The conductive metal plates (thesacrificial electrodes) could be the same or differentmaterials as of anodes (Pretorius et al., 1991) .
The mechanism of EC is greatly reliant on thechemical type of watery medium, particularly itsconductivity. The procedure of generating ions by ECis like iron and aluminum that are used as cathode andanode in this study. That is, in an electrolytic system,iron generates iron hydroxide. If the anode is made upof iron or steel or aluminum, for the production of themetal hydroxide, two mechanisms have been
proposed (Chen, 2004) .
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
6/12
Mohammadizaroun and YusoffTreatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
502
6. APPLICATION OF
ELECTROCOAGULATION IN THETREATMENT OF PAPER MILLWASTEWATER
Katal and Pahlavanzadeh (2011) have done a study onthe effectiveness of electrocoagulation on thetreatment of wastewater of paper mill by using varioustypes of electrodes with different combination ofaluminum (AL) and iron (Fe). They also investigatedthe effect of pH, current density, and temperature onthe removing process (Katal and Pahlavanzadeh,2011) .
7. APPLICATION OF
ELECTROCOAGULATION IN THE REMOVALOF CYANIDE
Because of strong affinity of cyanide with othermetals, it is used widely in different industries. So freecyanide and its related compounds can be found indifferent forms and density in the industrialwastewater that enter into the environment (Dash etal., 2009) .The aim of present study was to evaluate theefficiency of EC reactor with iron plate to remove free
cyanide from wastewater. The finding showed thatregarding the operational conditions, the mosteffective process was occurred at the voltage of 40 V,detention time of 90 min, and influent concentration
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
7/12
International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014
503
of 50 mg/l. Using EC technology for removingcyanide, in comparison with other removal methods,has many advantages economically. Despite usingelectrical power makes it costly, having no need to
prepare chemical material, which makes storing itsafer, enhances its efficiency and reliability. Due to itsefficiency in removing free cyanide and its relatedcomponents, EC can be used as a substitute methodfor removing cyanide from wastewater effluentscontaining cyanide (Hassani et al., 2011) .
8. REMOVAL OF TEXTILE DYEWASTEWATER BY ELECTROCOAGULATIONTECHNIQUE
Wastewaters that are produced by textile industries
contain a great deal of toxic aromatic combinations, particularly azodyesn. Due to increased amount ofeffluent wastewater in the environment, theinvestigations done in recent years were mostlyfocused on purifying wastewaters by application ofelectrocoagulation (EC) because it is a simple andspecific technique for producing drinking water andtreating wastewaters (Daneshvar et al., 2005) .
9. APPLICATION OFELECTROCOAGULATION IN THETREATMENT OF TANNERY WASTEWATER
Some characteristics of tannery wastewater are asfollows: it contains high chemical oxygen demand,
high total of floating solids, high biochemical oxygendemand, elevated oil and grease substances along withthe high chromium concentration and unpleasantcolor. Based on the mentioned characteristics, tannerywastewater can be severely problematic forenvironment. Thus one of the functions ofelectrocoagulation process was removing differentcontaminants and chromium from tannery wastewaterat the ambient temperature of the laboratory,simultaneously with other EC performances (Kongjaoet al., 2008)
10. CONCLUSION
Based on the conducted investigation, the best methodfor leachate treating is electrocoagulation technique
because leachate consists of high toxin mater such asheavy metal, cyanide, Colloid particle some of whichcannot be removed by other techniques. Accordingly,due to the mentioned advantages ofElectrocoagulation technique as well as itsadaptability with the environment, it has beenemployed as a practical method for industrial effluentand leachate treatment. The results of data in Table 1show that some of optimum conditions inelectrocoagulation process are: one centimeterdistance between electrodes, PH of 7-8.5, and theapproximate temperature of 28
Table 1: Effect of operational parameters on pollutant removal efficiency in electrocoagulation processRemo.
efficiency%
Effect oftemperatu
re(C)
Reactiontime
(minute)
Currentdensity
A/cm2
PH Distance betweenelectrode
(cm)
Type ofelectrodes
Surface ofelectrode
Cm 2
Removalfactor
PollutantSource
Studyscale
Lab/Pilot/Site
Location Reference
93.598.9
NG 4 NG 7 NG Al NG arsenic(As)
potablewater
Lab Turkey Mehmet
Kobya
a, 2011,
94.1,99.3
NG 2.5 2.5 6.5 NG Fe NG arsenic(As)
potablewater
Lab Turkey Mehmet
Kobyaa, 201
1, NG 30-90 60-140 3-
112 Al COD,
Turbidity,TS
Industrywastewater
Lab France (Zodi,Potieret al.2010)
96.2 NG 30 8 8 1 Fe 40cm Cr PlatingIndustrial
Wastewater
Lab India (Bhagawan,Poodari etal.
2014)
100 NG 20 0.01A/cm 2
3 0.1 Al- Fe NG Cr,Cu, Ni
Platingwastewater
Lab Turkey (Akbal and
Camc2011)
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
8/12
Mohammadizaroun and YusoffTreatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
504
56 NG 30 348-631
NG
6.5 Al 45 COD, NH 4-H
leachate Lab Germany (Ilhan,Kurtet al.2008)
35 NG 30 348-631
NG
65 Fe 45 COD, NH 4-H
leachate Lab Germany (Ilhan,Kurtet al.2008)
92,84
NG NG NG NG
1.5 Steel,Al
16 Color Pulp and paper
Industrialeffluent
Lab Malaysia (Kalyani,
Balasu bramanian et
al.2009)
95,89
NG NG NG NG
1.5 NG COD Lab Malaysia (Kalyani,
Balasu bramanian et
al.2009)
94,87,90
28 90 0.015A/cm 2
7 3 NG NG Colour,BOD,COD
Pulp, paperindustry
Lab India (Sridhar,
Sivak umaret al.2011)
99 NG 20-110 56-222 5 NG Al/Fe NG Cr Wastewater
Lab Iran (Keshmirizadeh,
Yousefi etal.
2011) 98 NG 30 0.00187
A/cm 2 6 1.5 Al- Fe 40 Colour Textile
industryLab Algeria (Aoud
j,Khelif a et al.2010)
88.4 20 30 0.070A/cm 2
5-7 NG Al- Fe 80 COD paper millwastewater
Lab Iran (Kataland
Pahlavanzad
eh2011)
63.8 20 NG Fe-Fe80
Colour techniquein the
treatmentof paper
millwastewater
Lab Iran Kataland
Pahlavanzad
eh2011)
99.9 20 Al-Al 80 Colour techniquein the
treatmentof paper
millwastewater
Lab Iran Kataland
Pahlavanzad
eh2011)
97 NG 90 40 1 Fe 60 CyanideSynthetic
WW
Lab Iran (Hassani,
Nasser i et al.2011)
97.5 NG 140 0.2 7 0.5 Al NG Cd water Lab India (Vasudevan,Lakshmi et
al.2011)
96.2 NG 140 7 0.5 Al NG (Vasudevan,Lakshmi et
al.2011)
85
80
14 0.03125A/cm 2
6-9 1 NG NG Red dye
COD
textile dyewastewater
Lab Tunisia (Merzouk,
Gourich et
al.2009)
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
9/12
International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014
505
Most of EC studies carried out in tempered climateand some of them had been assessed in tropical area.
Based on the information which filled in Table 1we can say that :
(1) Al and Fe are the most common electrode thatscientist use in researches
(2) Fe and Al can be used in both anode or cathode(3) Each of Fe and Al could be apply in both of
anode and cathode
(4) Depending on the type of wastewater andremoval factor ,retention time will be different
between 2.5 -140 minute(5) Distance of electrodes as a critical factor could
be controlled from 0.1- 6.5 Cm to achieve differentefficiency
(6) Since EC is a co treatment method for potablewater ,so efficiency of this method should be high
Fig. 2: experimental set up (Apparatus of the electrode process)
REFERENCE
Adhoum N, Monser L (2004). Decolourization andremoval of phenolic compounds from olive millwastewater by electrocoagulation. ChemicalEngineering and Processing: ProcessIntensification, 43(10): 1281-1287.
Akbal F, Camc S (2011). Copper, chromium andnickel removal from metal plating wastewater
by electrocoagulation. Desalination, 269(1):214-222.
Aoudj S, Khelifa A, Drouichea, N, Hecinia M,Hamitoucheb H (2010). Electrocoagulation
process applied to wastewater containing dyesfrom textile industry. Chemical Engineeringand Processing: Process Intensification, 49(11):1176-1182.
Bhagawan D, Poodari S, Pothuraju T, Srinivasulu D,
Shankaraiah G, Yamuna Rani M, Himabindu V,Vidyavathi S (2014). Effect of operational parameters on heavy metal removal byelectrocoagulation. Environmental Science andPollution Research, 1-8.
Calvo LS, Leclerc JP, Tanguy G, Cames MC,Paternotte G, Valentin G, Rostan A, Lapicque F(2003). An electrocoagulation unit for the
purification of soluble oil wastes of high COD.Environmental Progress, 22(1): 57-65.
Chen G (2004). Electrochemical technologies inwastewater treatment. Separation and
purification Technology, 38(1): 11-41.Daneshvar N, Salari D, Niaei A, Rasoulifard MH,
Khataee AR (2005). Immobilization of TiO2nanopowder on glass beads for the
photocatalytic decolorization of an azo dye CI
100 30 20 224 7-9 5 Fe-Fe 161 Cr tannerywastewater
Lab Thailand (Kong jao,Damr ongler d et al.2008)
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
10/12
Mohammadizaroun and YusoffTreatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
506
Direct Red 23. Journal of EnvironmentalScience and Health, Part A, 40(8): 1605-1617.
Dash RR, Gaur A, Balomajumder C (2009). Cyanidein industrial wastewaters and its removal: Areview on biotreatment. Journal of HazardousMaterials, 163(1): 1-11.
Hassani G, Nasseri S, Gharibi H (2011). Removal ofCyanide by Electrocoagulation Process.Analytical & Bioanalytical Electrochemistry, 3:625-634.
Holt PK (2006). Electrocoagulation: unravelling andsynthesising the mechanisms behind a watertreatment process. University of Sydney.Chemical Engineering.
Holt PK, Barton GW, Mitchell CA (2005). The future
for electrocoagulation as a localised watertreatment technology. Chemosphere, 59(3):355-367.
Holt PK, Barton GW, Wark , Mitchell CA (2002). Aquantitative comparison between chemicaldosing and electrocoagulation. Colloids andSurfaces A: Physicochemical and EngineeringAspects, 211(2): 233-248.
Ilhan F, Kurt U, Apaydin O, Gonullu MT (2008).Treatment of leachate by electrocoagulationusing aluminum and iron electrodes. Journal ofhazardous materials, 154(1): 381-389.
Kalyani K, Balasubramanian N, Srinivasakannan C(2009). Decolorization and COD reduction of
paper industrial effluent using electro-coagulation. Chemical Engineering Journal,151(1): 97-104.
Katal R, Pahlavanzadeh H (2011). Influence ofdifferent combinations of aluminum and ironelectrode on electrocoagulation efficiency:Application to the treatment of paper millwastewater. Desalination, 265(1): 199-205.
Keshmirizadeh E, Yousefi S, Rofouei MK (2011). Aninvestigation on the new operational parametereffective in Cr (VI) removal efficiency: A studyon electrocoagulation by alternating pulsecurrent. Journal of hazardous materials, 190(1):119-124.
Kobya M, Can OT, Bayramoglu M (2003). Treatmentof textile wastewaters by electrocoagulationusing iron and aluminum electrodes. Journal ofhazardous materials, 100(1): 163-178.
Kongjao S, Damronglerd S, Hunsom M (2008).Simultaneous removal of organic and inorganic
pollutants in tannery wastewater usingelectrocoagulation technique. Korean Journal ofChemical Engineering, 25(4): 703-709.
Merzouk B, Gourich B, Sekki A, Madani K, Vial C,Barkaoui M (2009). Studies on thedecolorization of textile dye wastewater by
continuous electrocoagulation process.Chemical Engineering Journal, 149(1): 207-214.
Mollah MY, Morkovsky P, Gomes JAG, Kesmez M,Parga J, Cocke DL (2004). Fundamentals,
present and future perspectives ofelectrocoagulation. Journal of HazardousMaterials, 114(1): 199-210.
Mouedhen G, Feki M, De Petris-Wery M, Ayedi HF(2009). Electrochemical removal of Cr (VI)from aqueous media using iron and aluminumas electrode materials: Towards a betterunderstanding of the involved phenomena.Journal of hazardous materials, 168(2): 983-991.
Pretorius W, Johannes W, Lempert GG (1991).
Electrolytic iron flocculant production with a bipolar electrode in series arrangement. WaterS.A., 17(2): 133-138.
Ratna Kumar P, Chaudhari S, Khilar KC, Mahajan SP(2004). Removal of arsenic from water byelectrocoagulation. Chemosphere, 55(9): 1245-1252.
Shafaei A, Rezayee M, Arami M, Nikazar M (2010).Removal of Mn ions from synthetic wastewater
by electrocoagulation process. Desalination,260(1): 23-28.
Song S, He Z, Qiu J, Xu L, Chen J (2007). Ozone
assisted electrocoagulation for decolorization ofCI Reactive Black 5 in aqueous solution: Aninvestigation of the effect of operational
parameters. Separation and purificationtechnology, 55(2): 238-245.
Sridhar R, Sivakumar V, Immanuel VP, Maran JP(2011). Treatment of pulp and paper industry
bleaching effluent by electrocoagulant process.Journal of hazardous materials, 186(2): 1495-1502.
Tchamango S, Nanseu-Njiki CP, Ngameni E, HadjievD, Darchen A (2010). Treatment of dairyeffluents by electrocoagulation usingaluminium electrodes. Science of the totalenvironment, 408(4): 947-952.
Vasudevan S, Lakshmi J, Sozhan G (2011). Effects ofalternating and direct current inelectrocoagulation process on the removal ofcadmium from water. Journal of hazardousmaterials, 192(1): 26-34.
Vepslinen M, Ghiasvand M, Selin J, Pienimaa J,Repo E, Pulliainen M, illanp M (2009).Investigations of the effects of temperature andinitial sample pH on natural organic matter(NOM) removal with electrocoagulation usingresponse surface method (RSM). Separationand Purification Technology, 69(3): 255-261.
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
11/12
International Journal of Scientific Research in Knowledge, 2(11), pp. 497-508, 2014
507
Wan W, Pepping TJ, Banerji T, Chaudhari S,Giammar DE (2011). Effects of waterchemistry on arsenic removal from drinkingwater by electrocoagulation. water research,45(1): 384-392.
Wang CT, Chou WL, Kuo YM (2009). Removal ofCOD from laundry wastewater byelectrocoagulation/electroflotation. Journal ofhazardous materials, 164(1): 81-86.
Yilmaz AE, Boncukcuolu R, Kocakerim MM,Yilmaz MT, Paluluolu C (2008). Boronremoval from geothermal waters byelectrocoagulation. Journal of hazardousmaterials, 153(1): 146-151.
Zodi S, Potier O, Lapicque F, Leclerc JP (2009).Treatment of the textile wastewaters byelectrocoagulation: Effect of operating
parameters on the sludge settlingcharacteristics. Separation and purificationTechnology, 69(1): 29-36.
Zodi S, Potier O, Lapicque F, Leclerc JP (2010).Treatment of the industrial wastewaters byelectrocoagulation: Optimization of coupledelectrochemical and sedimentation processes.Desalination, 261(1): 186-190.
8/10/2019 Treatment of Leachate by Electrocoagulation Technique Using Iron And Hybrid Electrodes
12/12