Chemical Engineering Journal 147 (2009) 259264

Contents lists available at ScienceDirect

Chemical Engineering Journal

journa l homepage: www.e lsev ier .c

Phenol

Haipinga School of Envi 0275,b Western Rese

a r t i c l

Article history:Received 13 MReceived in reAccepted 2 Jul

Keywords:Electricity genMicrobial fuelMFCPhenol degradBiodegradatio

a greancingthe sode Mtion.ontrode. Ws depsed aand 9

strate consumption. The maximal power densities were 9.1 and 28.3W/m for MFCs using phenol andglucosephenol mixture as the fuel, respectively. Co-occurring with electricity generation, the degrada-tion efciencies of phenol in all the MFCs reached above 95% within 60h. The results indicate that the

1. Introdu

Microbusing a vaacetate, mand biodeand domecases, somcontaminaterm applwastewatevaries onlar designsbut 261mdomesticwere founthe wastewMFC reseatrant contaresearch.

CorrespE-mail ad

1385-8947/$doi:10.1016/jMFC can enhance biodegradation of recalcitrant contaminants such as phenol in practical applications. 2008 Elsevier B.V. All rights reserved.

ction

ial fuel cells (MFCs) have been operated successfully byriety of readily degradable compounds, such as glucose,onosaccharides, and complex carbohydrates (e.g., starchgradable organics in food wastewater, swine wastewater,stic wastewater), as substrates (the fuel) [15]. In a fewe biorefractory organics, such as cellulose and petroleumnts, were also used as the fuel in MFCs [6,7]. The near-ication for MFCs was presumed to generate power fromr [8]. The amount of power produced from the MFCs

the specic sources of the fuel. For example, with simi-of the MFC, 506mW/m2 was produced with acetate [3],

W/m2 with swine wastewater [2], and 146mW/m2 withwastewater [9]. Toxic and biorefractory organics, whichd frequently in the wastewater, have a great inuence onater treatment and should be concerned in the related

rch. However, the development of MFCs using recalci-minantsas fuels is still in its infancyandwarrants further

onding author. Tel.: +86 20 84110052; fax: +86 20 84110692.dresses: liugl@mail.sysu.edu.cn, luohaiping2004@126.com (G. Liu).

Phenol has been detected in efuents from industries, includingcoal gasication, pharmacy, and productions of pesticides, fertiliz-ers, dyes, and other chemicals. Although phenol is biodegradableboth aerobically and anaerobically, it can be growth inhibitory tomicroorganisms at elevated concentrations, even to those speciesthat can use it as a substrate [10]. Degradation of phenol was alsofound incomplete for concentrations higher than 400mg/L, and theresidual phenol might inhibit the removal of N and P in wastewatertreatment [11].

In the anaerobic environment, phenol was degraded bymethanogens, denitrifying, iron bacteria, and sulfate-reducing bac-teria [1214]. However, methane-producing processes have notbeen widely used due to low energy recovery from phenol andhigh operational costs [15]. In the MFC, electricity can be produceddirectly from the degradation of organic matter and high energyrecovery can be obtained [16]. While under the denitrifying, iron,and sulfate-reducing conditions, the exhaustion of these electronacceptorsmayprevent the complete degradation of phenol, and theanaerobic degradation rates are usually lower than that under aer-obic conditions. In the MFC, electrons released from the substrateoxidation in the anode are transferred via the external circuit tothe cathode, where the electrons are eventually consumed by theterminal electron acceptors. The terminal electron acceptors can beeasily replaced or even non-exhausted (e.g., using oxygen in ambi-ent air as the electron acceptor) [7]. Combining with the benet

see front matter 2008 Elsevier B.V. All rights reserved..cej.2008.07.011degradation in microbial fuel cells

Luoa, Guangli Liua,, Renduo Zhanga, Song Jinb

ronmental Science and Engineering, Sun Yat-sen University, Guangzhou, Guangdong 51arch Institute, Laramie, WY 82072, USA

e i n f o

arch 2008vised form 25 June 2008y 2008

erationcell

ationn

a b s t r a c t

Microbial fuel cell (MFC) has gainedity directly from and potentially enhaphenol or glucosephenol mixture astion of phenol. In an aqueous air cathgenerated during the phenol degrada15% as compared to the open-circuit cpacked MFC with a ferricyanide cathowas obtained when 90% of phenol wawhen phenolglucose mixture was upeaks, phenol was degraded by 20%om/ locate /ce j

China

t attention attributable to its ability in generating electric-biodegradation of contaminants. In this study, MFCs using

ubstrate (fuel) were designed to investigate the biodegrada-FC using phenol (400mg/L) as the sole fuel, electricity was

The degradation rates of phenol in the MFC increased aboutl. Further experiments were conducted by using a graphite-hen phenol served as the sole fuel, the peak voltage outputleted. A unique pattern of twin voltage peaks was observeds the fuel. At the occurrence of the rst and second voltage0%, respectively, suggesting a preferential sequence in sub-

3

260 H. Luo et al. / Chemical Engineering Journal 147 (2009) 259264

Fig. 1. Schemcyanide cathod

of power geoffer a newcontaminan

This stugenerationMFC usingof the expeas fuel in thing shock loof co-subststrates. To oby the anodbeen investdegradable

2. Materia

2.1. MFC se

Double cduction fromthat arise dlarly, in thiswas construwas 7.0 cm.Toray Co., Jawas coatedside. The anThe cathode(PBS) (pH 7cathodic coanode and cpaper.

In followgranular grin both ano

were made of carbon cloth (UT70-20, Toray Co., Japan) of the samesize (2.0 cm14.0 cm). The anode and cathode were separated by

n exchange membrane (PEM, Naon 212, Dupont Co., USA).al vog andhe ae, a 1iumn ths ofleak tn accycledoppence os wewas

an 50thos

icrob

teriaenet25].00m(1:1elec

ed frngzhre-ae MFths.eph

g/Lby ter of0.31atic diagrams of MFCs using an aqueous air cathode (A) and a ferri-e (B).

neration in offsetting the treatment cost, the MFC maytechnique in enhancing biodegradation of recalcitrantts such as phenol in practical applications.dy determined the degradation of phenol and powerin an MFC with aqueous air cathode and a packing-typeferricyanide as the terminal electron acceptor. In somerimental treatments, co-substrate of glucose was usede MFCs to reduce potential toxicity from phenol dur-ad or temperature changes [17,18]. In addition, the userates better represented eld situations of mixed sub-

a protoThe totpackintively. Tcathodpotassbetweethe losmightelectrowere c

A cresistasurfacevoltageless thrials as

2.2. M

Bacphylogria [21with 2sludgesity ofcollectof Guausing pcathod5 monglucos(1000mducted(per litNH4Clur knowledge, the sequential utilization of substratesic bacteria in the MFC during power generation has notigated, when both recalcitrant (e.g., phenol) and readily(e.g., glucose) substrates are mixed.

ls and methods

tup

hamber MFCs are often used in examining power pro-using different substrates, or microbial communities

uring the degradation of specic compounds [8]. Simi-study a dual-chamber MFC with aqueous air cathodected as shown in Fig. 1A. The diameter of the chambersThe electrodesweremade of carbon paper (TGP-H-060,pan) of the same size (5.0 cm5.0 cm) and the cathodewith a platinum (Pt) catalyst (0.40mgPt/cm2) on oneode chamberwas lledwith substrate solution (pH7.0).chamber was lled with the phosphate buffer solution

.0) and continuously sparged with air. Both anodic andmpartments have the same volume of 440.0mL. Theathode chambers were separated by a piece of carbon

-up tests, a packing-type MFC was constructed usingaphite (#1620, porosity 10%) as the packing materialde and cathode chambers (Fig. 1B). Both electrodes

tion 12.5m7.0 and all M30.00.1 C

2.3. Analys

Samplesmeasuremecentrationsconcentratitrophotome

Voltagesmeter and dsystem. Aresity (PV, W/

PA =IU

A

PV =IU

V

where I is tface area ofvolume of tmedia) (m3

power is genlume of the anodic compartment was 58.0mL with thenon-packing net volumes of 25.4 and 32.6mL, respec-

node chamberwaslledwith substrate (pH7.0). For the00mM PBS was prepared and enriched with 50mM ofhexacyanoferrate to optimize mass transfer efciencye cathode and terminal electron acceptor, and to avoidsubstrate (i.e., phenol) due to dissolved oxygen, whichhrough the PEM membrane and used by bacteria as theeptor [19,20]. The substrate and ferricyanide solutionsusing a peristaltic pump with a ow rate of 20mL/min.r wire was used to connect the circuit containing af 1000 (unless stated otherwise). All exposed metalre sealed with nonconductive epoxy resin. When thelower than 50mV and the phenol concentration wasmg/L, the chambers were relled with the same mate-e at the initial stage.

ial inoculum and medium

that thrive in MFC biolms are distributed across manyic subclasses, such as-,-, -, -subclass Proteobacte-For quick start-upof theMFC, theMFCswere inoculatedL of mixed aerobic activated sludge and anaerobic, v/v), which were known to contain a greater diver-trochemical active bacteria. The sludge inocula wereom the Liede Municipal Wastewater Treatment Plantou City, China. The packing-type MFCs were inoculatedcclimated bacteria from the anode of an aqueous airC that had been running in the fed batch mode for overSubstrates used in the experiments included glucose,enolmixture, andphenol. The experimentswith phenol) and glucose (500mg/L) as the mixed fuels were con-he packing-type MFC. The anodic medium consisted ofdeionized water): Na2HPO4 4.0896g, NaH2PO4 2.544g,g, KCl 0.13g, tracemetals solution 12.5mL, vitamin solu-L [26]. The initial pH of all solutions was adjusted toFCs were operated in a temperature-controlled lab at.

is

of the anode solutions were taken every 12h fornts of glucose and phenol concentrations. Glucose con-were analyzed by the anthrone method [27]. Phenolons were analyzed using the 4-aminoantipyrine spec-tric method [28].across the resistance were measured using a multi-ata were automatically recorded by a data acquisitiona power density (PA, W/m2) and volumetric power den-m3) are calculated as follows:

(1)

(2)

he current (A), U is the voltage (V), A is the cross sur-the anode or cathode (m2), and V is the non-packinghe anodic compartment (i.e., the volume of the liquid). The volumetric power density indicates how mucherated fromunit volumeofwastewater. TheCoulombic

H. Luo et al. / Chemical Engineering Journal 147 (2009) 259264 261

Fig. 2. Electricity voltage output of the aqueous air cathode MFC using phenol assole fuel at a concentration of 400mg/L. The arrow shows the time of anode solutionreplacement.

efciencies

CE =n

i=1RFb

Here Ui is ttance, F isnumber ofof e/mol oV is the liq(32g/mol) [

The maxsubstrate tothe externathe voltagethen calcula

3. Results

3.1. Power gcathode

Power wphenol (40observed bemaximumo(theexternacycles wereof the repremaximum osity obtaine

Table 1Concentrationconditions

Time (h) Cl

Ph

0 4024 2748 1972 1396 7

120 3144 1

a The mean

Fig. 3. ElectricMFC using phe

(R=1000ova

nol dto th

thenedcalcu

wer

ursua paccepterrics airctricoltagum oablytionshin 4chamolwk (Fi

uennide

en ptput(CEs) (%) are calculated by:

UitiSV

M 100% (3)

he output voltage of MFC at time ti, R is external resis-Faradays constant (96 485C/mol electrons), b is themoles of electrons produced per mol of COD (4molf COD), S is the removal of COD concentration (g/L),uid volume (L), M is the molecular weight of oxygen3].imum power density was determined by adding freshthe MFC and establishing constant power, changing

l resistances over a range of 505000, and recording(typically 510min per resistance) [29]. The power wasted for each resistance as a function of the current.

eneration from phenol in the MFC with aqueous air

as generated in the MFC with aqueous air cathode and0mg/L) as the sole fuel. A lag time about 300h wasfore the constant voltage output was established. Theutputvoltagemeasuredwas in the rangeof111140mVl resistanceR=1000). Constantandrepeatablepowerobtained during six rells of the anode chamber. Onesentative cycles was presented in Fig. 2. The averageutput voltage and the average maximum power den-

age remPhe

paredrates inthe opevalues

3.2. PoMFC

To ptestedtron acusing faqueouous elepeak vmaximpresumpopula

Witanodeof phenthe pea

3.3. Inferricya

Whage oud from the MFC were 121mV and 6mW/m2 (anode)

s and removal rates of phenol inMFCsunder closed andopened circuit

osed circuit Opened circuit

enol (mg/L) Phenol removal(%)

Phenol (mg/L) Phenol removal(%)

0.0 0 400.0 01.326.3a 32.26.6 326.43.7 18.40.98.344.0 50.411.0 237.98.5 40.52.10.737.4 67.39.3 163.818.7 59.04.76.327.7 80.96.9 105.921.7 73.55.49.615.6 90.13.9 64.718.1 83.84.58.26.7 95.51.7 46.615.6 88.33.9value and standard deviation of multiple cycles (n=3).

on the voltvoltage appfollowing tsistent thropeaks (>650600mV).

Consumincrease ofreached80%of phenol wand 90% atof phenol w

Power dat externalFig. 5, wheimal volumwith a currity voltage output and the phenol removal of the ferricyanide cathodenol as sole fuel at a concentration of 1000mg/L.

), respectively. At the end of each power cycle, the aver-l of phenol was 85%.egradation rates in MFCs with closed circuit were com-ose in MFCs with opened circuit. Phenol degradationclosed circuit MFCs were 814% higher than those incircuitMFCs, based on themean and standard deviationlated from multiple runs (Table 1).

generation from phenol using ferricyanide cathode

e greater power output from phenol as the fuel, weking-type MFC using ferricyanide as the terminal elec-or. Shorter acclimation time was observed in the MFCsyanide cathode (about 80h) than that in the MFCs usingcathode (about 300h). During eight cycles of continu-ity generation with 1000mg/L phenol as the fuel, onee occurred corresponding to each cycle (Fig. 3). Theutput voltage ranged from 387 to 540mV (R=1000),attributable to the metabolic uctuations of microbialin the anode chamber.8h of each electrical cycle, the removal of phenol in theber reached more than 90%. The maximal removal rateas usually at the pointwhen the voltage output reachedg. 3).

ce of the supplemental glucose on the performance ofcathode MFC

henolglucose mixture was used as the fuel, the volt-of the MFCs showed a distinctive twin-peak patternagetime curves. After each fuel rell, the rst peakeared within 10h and the second peak emerged 28hhe rst peak. This twin-peak pattern remained con-

ughout the electrical cycles (Fig. 4), and the rstmV) were always higher than the second ones (about

ptions of phenol and glucose corresponded with theoutput voltages. The average degradation of glucosewithin 12hof theMFCestablishment. The degradationas close to 20% when the rst peak voltages appearedthe second peak voltage. Within 60h, the degradationas above 95% (Table 2).ensity was obtained by measuring stabilized voltagesresistances ranging from 50 to 5000. As shown inn the rst peak voltage (635mV) appeared, the max-etric power density was determined to be 28.3W/m3

ent density of 58.9A/m3, and the corresponding max-

262 H. Luo et al. / Chemical Engineering Journal 147 (2009) 259264

Fig. 4. Electricity voltage output of the MFC using phenolglucose mixture as fuel.The arrows show the replacement time of fuels. The square and circle show the timeof the rst and second voltage peaks in each cycle, respectively.

imal area power density was 342.0mW/m2 (cathode). When thesecond peak voltage (599mV) appeared, the maximal volumet-ric power density and area power density were 12.6W/m3 and152.2mW/m2 (cathode), respectively, with a current density of39.3A/m3.

3.4. Substrate utilization in the ferricyanide cathode MFC

The amounts of coulomb recovery by the MFCs were calcu-lated based on the electrical cycles shown in Fig. 6. The electricalcharges obtained by theMFCwere 92.0, 47.8, and 39.4Cwhenusingphenolglutively. The C1.5% when ufuel, respec

Table 2Concentrationfuel

Time (h)

01236486072

a The meanb Not detect

Fig. 5. Powersymbols) peak

Fig. 6. Voltagemixture as fue

4. Discussi

4.1. Power g

The studas the termpower densthan that frsuch as 494[9,3]. The recapable micdationand l

ximation,rgered asentiaenolwer gmaxedwantlyphelthorbonureprim

c acidgrees apd ascose mixed, glucose, and phenol as the fuel, respec-oulombic efciencies of the MFC were 2.7%, 7.7%, andsing phenolglucose mixed, glucose, and phenol as thetively.

s of phenol and glucose in MFCs using phenolglucose mixture as the

Phenol (mg/L) Glucose (mg/L)

1000 500709.629.4a 86.21.7403.063.1 3.42.4153.328.5 0.90.80.20.3 NDbND ND

value and standard deviation of multiple cycles (n=3).ed.

(approgeneravide lawas using potthe phthe poto theMFCs fimportsuch asation. Asole camost plize areorganistudyaulationare usedensity curves when the rst (hollow symbols) and second (solidvoltages appeared.

molecular tanode and i

The maxing phenoltheMFCs coably stimulaanode chamunit time frby the same

Theobseusing phenAlthough itstrate degratwo peakswas difcudegradationtime curves for theMFCs using glucose, phenol, and phenolglucosels.

on

eneration

y was initially conducted using the MFC with oxygeninal electron acceptor in the cathode. The maximumity (6mW/m2 anode) obtained was substantially lowerom MFC studies using readily degradable compounds,mW/m2 from glucose and 305mW/m2 from butyratecalcitrance of phenol and the inadequate population ofrobes might have resulted in the slower phenol degra-owerpoweroutput, as attestedby theextended lag timetely 300h). To improve the MFC efciency in electricitya graphite packing-type MFC was constructed to pro-surface areas to enhance bacterial growth. Ferricyanidethe cathode electron acceptor due to its higher oxidiz-l than oxygen,which avoided the inuence of oxygen toremoval. When using 1000mg/L phenol as the sole fuel,enerated (9.1W/m3 with R=1000) was comparable

imum power densities obtained from oxygen cathodeith acetate (12.7W/m3) or butyrate (7.6W/m3) [3].More, our results demonstrate that recalcitrant compoundsnol can be used as the fuel in the MFC for power gener-ugh Geobacter species can use aromatic compounds assources and electron donors, the carbon sources that

cultures of various electricity-generating bacteria uti-arily limited to easily biodegradable organics, such ass and fermentative products [3032]. Results from thisdwithothers in the literature thatmixedmicrobial pop-pear to perform well in MFCs when complex organicsthe fuel [2,5,33]. Efforts are currently attempted to use

echniques tocharacterizemicrobial communitieson then the anodic chamber in the phenol-degrading MFCs.imal voltage outputs obtained from the MFCs contain-glucose mixture were obviously higher than that fromntainingphenol only. Theglucose co-substratepresum-ted the growth ofwhole populations ofmicrobes in theber. In addition, more electrons might be generated in

om the synchronous degradation of phenol and glucoseor different consortia of microbes.

rved twin-peakpatternof thevoltagepeaks in theMFCsolglucose mixed fuel has not been reported before.appeared that there was a preferential order in sub-dation for the mixed substrates, the correlation of thewith the degradation sequence of glucose and phenollt to determine, because of the possible formation ofintermediates.

H. Luo et al. / Chemical Engineering Journal 147 (2009) 259264 263

Fig. 7. Compaphenolglucos

4.2. Degrad

Results fphenol degwhich the nthis enhanctron acceptacceptors suber, realizinMFC technobic environmof indigeno

Tay et altrations of 5concentratiof glucosedegradationber of thewhen phentive delayincreased thwas resume

4.3. Coulom

The powlower thanof coulombglucose (caglucose conthat the deMFC power[3,8]. The aby the phenpower fromand glucoseapparentlytricity gene

The Coulwas less thelectrons invary widelyattribute toof phenol wCOD removwas oxidizearchaea. Th

MFC and the open-circuit control indicated that other respiratorymanners, such as methane-production, were carried out simulta-

y with the electron transfer to the electrode. (3) Electronsrredthe sygencan

clus

tricidoubd pohenothehe Mopengraserv0% o

aks wfuel.wasntialdenscose

lectrie MFC mtrant

wled

worrogrntal000770 a

nces

abaeyonver(2003in, J.Rtewatiu, S.g a s662.atal, Kridesrison of phenol degradation rates in the MFCs using phenol ande mixture as fuels.

ation of organic compounds

rom this study demonstrate that the MFC can enhanceradation as compared to the open-circuit controls, inormal anaerobic metabolism prevailed. We attributedement to the transfer of electrons to the terminal elec-or of oxygen in the cathode, instead of other electronch as sulfate and metals in the anaerobic anode cham-g an indirect aerobic degradation [7]. Therefore, thelogy may be applied in phenol treatment in the anaero-ent such as groundwater,which is frequently depleted

us terminal electron acceptors (e.g., nitrate or Fe3+).. [18] indicated that glucose supplement at the concen-004000mg/L promoted biodegradation of phenol at

ons of 4202100mg/L. As shown in Fig. 7, a supplementat 500mg/L initially delayed the phenol (1000mg/L)

in the MFC. Microorganisms in the anode cham-MFCs might prefer glucose as the initial substrateolglucose mixture was the fuel, rendering a tenta-in phenol degradation. When microbial populationsrough glucose metabolism, the degradation of phenold and substantially enhanced.

bic efciency and substrate utilization

er generation using phenol as the sole fuel wasthat using glucose, although the theoretical amounts contained in phenol was three times higher thanlculations based on the concentrations of phenol andtaining in the substrates). Results of CEs indicated

gradability of substrates had a great inuence on thegeneration, which was consistent with other studies

neousltransfetors inand oxa signi

5. Con

Elecfuel ina mixeusing pduringnol in tto theusing aphenolwhen 9age peas thephenolpreferepowerand gluwith ein all ththat Mrecalci

Ackno

ThisFund Pronme2006K506080

Refere

[1] K. Rof c25

[2] B.Mwas

[3] H. Lusin658

[4] T. Cchamount of electrical charges obtained by MFCs fueledolglucose mixture was 4.8C higher than the sum ofthe two MFCs fueled with the same amount of phenolindividually. The presence of the glucose co-substrate

enhanced the phenol degradation and subsequent elec-ration.ombic efciency calculated based on the total substratean 10% in the MFCs, indicating a substantial loss ofthe system. Coulombic efciencies reported by othersfrom 0.04% to 97% [23,31,34,35]. Many factors couldthe electron consumption in MFCs: (1) Mineralizationas incomplete in the anode chamber, based on that theals were in the range of 83.996.4%. (2) The substrated by other anaerobic microbes such as methanogenice comparison of phenol removals in the closed circuit

[5] J. Niessenbial electrCommun

[6] Z. Ren, T.Ebial fuel4781478

[7] J. Morris,diation o1823.

[8] B.E. LoganSci. Techn

[9] H. Liu, B.EmicrobialEnviron. S

[10] G.A. Hill,Pseudomo

[11] A. Uygur,sequencin

[12] H.H.P. Fanwastewatfrom substrate to other non-electrode electron accep-olution, such as sulfate that came in with trace metals[9]. (4) System internal resistance may also account fort portion of the reduction in the CE.

ions

ty was successfully generated by using phenol as thele chamberMFCs inoculatedwith sludge that containedpulations of bacteria. In an aqueous air cathode MFCl (400mg/L) as the sole fuel, electricity was generated

phenol degradation; and the degradation rates of phe-FC were increased by approximately 15% as compared-circuit controls. Further experiments were conductedphite-packed MFC with a ferricyanide cathode. Whenedas the sole fuel, thepeakvoltageoutputwasobtainedf phenol was depleted. A unique pattern of twin volt-as observed when phenolglucose mixture was used

At the occurrence of the rst and second voltage peaks,depleted by 20% and 90%, respectively, suggesting asequence in the substrate consumption. The maximalities were 9.1 and 28.3W/m3 for MFCs using phenolphenol mixture as the fuel, respectively. Co-occurringcity generation, the degradation efciencies of phenolFCs reached above 95% within 60h. The results indicateay be a novel method in enhancing biodegradation ofcontaminants such as phenol in practical applications.

gements

k was partially supported by grants from the Researcham of Guangdong Provincial Key Laboratory of Envi-Pollution Control and Remediation Technology (no.) and the Natural Science Foundation of China (nos.nd 50779080).

, G. Lissens, S.D. Siciliano, W. Verstraete, A microbial fuel cell capableting glucose to electricity at high rate and efciency, Biotechnol. Lett.) 15311535.. Kim, S.E. Oh, J.M. Regan, B.E. Logan, Electricity generation fromswineer using microbial fuel cells, Water Res. 39 (2005) 49614968.Cheng, B.E. Logan, Production of electricity from acetate or butyrateingle-chamber microbial fuel cell, Environ. Sci. Technol. 39 (2005)

. Li, H. Bermek, H. Liu, Electricity production from twelve monosac-using microbial fuel cells, J. Power Sources 175 (2008) 196200., U. Schrder, F. Scholz, Exploiting complex carbohydrates for micro-icity generation-a bacterial fuel cell operating on starch, Electrochem.. 6 (2004) 955958.. Ward, J.M. Regan, Electricity production from cellulose in a micro-

cell using a dened binary culture, Environ. Sci. Technol. 41 (2007)6.S. Jin, Feasibility of using microbial fuel cell technology for bioreme-f hydrocarbons in groundwater, J. Environ. Health Part A 43 (2008)

, J.M. Regan, Microbial fuel cell: challenges and technology, Environ.ol. 40 (2006) 51725180.. Logan, Electricity generation using an air-cathode single chamberfuel cell in thepresence andabsenceof a protonexchangemembrane,ci. Technol. 38 (2004) 40404046.C.W. Robinson, Substrate inhibition kinetics: phenol degradation bynas putida, Biotechnol. Bioeng. 17 (1975) 15991615.F. Kargi, Phenol inhibition of biological nutrient removal in a four-stepg batch reactor, Process Biochem. 39 (2004) 21232128.g, D.W. Liang, T. Zhang, Y. Liu, Anaerobic treatment of phenol iner under thermophilic condition, Water Res. 40 (2006) 427434.

264 H. Luo et al. / Chemical Engineering Journal 147 (2009) 259264

[13] D.R. Lovley, D.J. Lonergan, Anaerobic oxidation of toluene, phenol, and p-cresolby the disssimilatory iron-reducing organism, GS-15, Appl. Environ. Microb. 56(6) (1990) 18581864.

[14] M.M. Broholm, E. Arvin, Biodegradation of phenols in a sandstone aquifer underaerobic conditions and mixed nitrate and iron reducing conditions, J. Contam.Hydrol. 44 (2000) 239273.

[15] G.S. Veeresh, P. Kumar, I. Mehrotra, Treatment of phenol and cresols in upowanaerobic sludge blanket (UASB) process: a review, Water Res. 39 (2005)154170.

[16] B.E. Logan, Extracting hydrogen and electricity from renewable resources, Env-iron. Sci. Technol. 38 (9) (2004) 160A167A.

[17] P.C. Hwang, S.S. Cheng, The inuence of glucose supplement on the degradationof catechol, Water Sci. Technol. 23 (1991) 12011209.

[18] J.H. Tay, Y.X. He, Y.G. Yan, Improved anaerobic degradation of phenol with sup-plemental glucose, J. Environ. Eng. 127 (1) (2001) 3845.

[19] S. Oh, B. Min, B.E. Logan, Cathode performance as a factor in electricity gener-ation in microbial fuel cells, Environ Sci. Technol. 38 (2004) 49004904.

[20] S. Oh, B.E. Logan, Proton exchange membrane and electrode surface areas asfactors that affect power generation in microbial fuel cells, Appl. Microbiol.Biotechnol. 70 (2006) 162169.

[21] B.H. Kim, H.S. Park, H.J. Kim, G.T. Kim, I.S. Chang, J. Lee, N.T. Phung, Enrichmentof microbial community generating electricity using a fuel-cell-type electro-chemical cell, Appl. Microbiol. Biotechnol. 63 (2004) 672681.

[22] B.E. Logan, C. Murano, K. Scott, N.D. Gray, I.M. Head, Electricity generation fromcysteine in a microbial fuel cell, Water Res. 39 (2005) 942952.

[23] D.R. Bond, D.E. Holmes, L.M. Tender, D.R. Lovley, Electrode-reducing microor-ganisms that harvest energy from marine sediments, Science 295 (2002)483485.

[24] D.E. Holmes, D.R. Bond, R.A. ONeil, C.E. Reimers, L.R. Tender, D.R. Lovley,Microbial communities associated with electrodes harvesting electricity froma variety of aquatic sediments, Microb. Ecol. 48 (2004) 178190.

[25] N.T. Phung, J. Lee, K.H. Kang, I.S. Chang, G.M. Gadd, B.H. Kim, Analysis of micro-bial diversity in oligotrophic microbial fuel cells using 16S rDNA sequences,FEMS Microbiol. Lett. 233 (2004) 7782.

[26] D.R. Lovely, E.J.P. Phillips, Novel mode of microbial energy metabolism:organism carbon oxidation coupled to dissimilatory reduction of iron andman-ganese, Appl. Environ. Microbiol. 54 (6) (1988) 14721480.

[27] K. Raunkjer, H. Thorkild, P. Nielsen, Measurement of pools of protein, car-bohydrate and lipids in domestic wastewater, Water Sci. Technol. 28 (1994)25l262.

[28] State Environmental Protection Administration of China, Monitoring and Anal-ysis Methods of Water and Wastewater, third ed., China Environmental SciencePress, Beijing, 1989, pp. 354356.

[29] B.E. Logan, B. Hamelers, R. Rozendal, U. Schrder, J. Keller, S. Freguia, P.Aelterman, W. Verstraete, K. Rabaey, Microbial fuel cells: methodology andtechnology, Environ. Sci. Technol. 40 (17) (2006) 51815192.

[30] D.R. Lovley, Bug juice: harvesting electricity with microorganisms, Nat. Rev.Microbiol. 4 (2006) 497508.

[31] D.R. Bond, D.R. Lovley, Electricity Production by Geobacter sulfurreducensattached to electrodes, Appl. Environ. Microb. 69 (3) (2003) 15481555.

[32] K. Rabaey, N. Boon, S.D. Siciliano, M. Verhaege, W. Verstraete, Biofuel cellsselect formicrobial consortia that self-mediate electron transfer, Appl. Environ.Microb. 70 (2004) 53735382.

[33] Y. Zuo, P.C. Manessand, B.E. Logan, Electricity production from steam explodedcorn stover biomass, Energy Fuels 20 (2006) 17161721.

[34] H.S. Park, B.H. Kim, H.S. Kim, H.J. Kim, G.T. Kim, M. Kim, I.S. Chang, Y.K. Park,H.I. Chang, A novel electrochemically active and Fe (III)-reducing bacteriumphylogenetically related to Clostridium butyricum isolated from a microbial fuelcell, Anaerobe 7 (2001) 297306.

[35] S.K. Chaudhuri, D.R. Lovley, Electricity generation by direct oxidation of glu-cose in mediator-less microbial fuel cells, Nat. Biotechnol. 21 (10) (2003)12291232.

Phenol degradation in microbial fuel cellsIntroductionMaterials and methodsMFC setupMicrobial inoculum and mediumAnalysis

ResultsPower generation from phenol in the MFC with aqueous air cathodePower generation from phenol using ferricyanide cathode MFCInfluence of the supplemental glucose on the performance of ferricyanide cathode MFCSubstrate utilization in the ferricyanide cathode MFC

DiscussionPower generationDegradation of organic compoundsCoulombic efficiency and substrate utilization

ConclusionsAcknowledgementsReferences