Decolorization of Biogas Effluent from Palm Oil Mill Using Combined Biological and Physical Methods

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1 Ksetsrt J. (Nt. Sci.) 48 : 9-14 (14) Decoloriztion of Biogs Effluent from Plm Oil Mill Using Comined Biologicl nd Physicl Methods Sursk Bunrung 1, Suteer Prsertsn 2, Poonsuk Prsertsn 1,3* ABSTRACT Two mixed cultures (Super LDD.1 nd Super LDD.2) were used s inocul (1%) for the decoloriztion nd tretment of iogs effluent from plm oil mill (BEPOM) under eroic (2. volume of ir per volume of medium per minute, vvm) nd microeroic conditions, respectively. With the supplementtion of 1% plm oil mill effluent (POME) s nutrients, Super LDD.1 nd Super LDD.2 showed higher decoloriztion thn the Super EM culture under microeroic conditions fter 4 d cultivtion. The optimum inoculum size for oth sources ws % (volume per volume) nd Super LDD.1 produced higher decoloriztion (27.%) nd phenol removl (.4%) thn Super LDD.2 (16.7% nd 12.1%, respectively) fter 2 d cultivtion. However, Super LDD.1 exhiited slightly lower chemicl oxygen demnd (COD) removl thn Super LDD.2 (27.8% nd 29.2%, respectively) fter 6 d cultivtion. The effluent fter tretment y Super LDD.1 ws susequently tested for the effect of ph nd plm sh concentrtion (1 1%, weight per volume) under mixing conditions (on 12 rpm shker) t room temperture (3 ± 3 C) for 1 h. The highest decoloriztion (84.7%), phenol removl (9.8%) nd COD removl (88.9%) were chieved t 1% (w/v) plm sh. The results indicted the potentil tretment of BEPOM using iologicl method (Super LDD.1 culture) in comintion with physicl method (plm sh) which ws etter thn using ech tretment lone. Keywords: decoloriztion, iogs effluent, iologicl methods, physicl method INTRODUCTION The plm oil industry is n importnt gro-industry in Southern Thilnd producing t plm oil in 1 (Office of Agriculturl Economics, 1). The plm oil mill extrction process genertes three mjor sources of the effluent: seprtor sludge, sterilizer condenste nd hydrocyclone effluent with totl quntity per fresh fruit unch (FFB) of.87 m 3.t 1 (H-Kittikul et l., 1994). Nowdys, plm oil mill effluent (POME) is commonly used for iogs production s replcement for tretment using n neroic pond. The iogs system employed in most Thi plm oil mills is completely stirred tnk rector nd n neroic covered lgoon. Biogs is now source of renewle energy tht could e used directly or converted to het nd electricity. Therefore, electricity cn ecome nother mjor product in some plm oil mills in Thilnd. 1 Deprtment of Industril Biotechnology, Fculty of Agro-Industry, Prince of Songkl University, Songkhl 9112, Thilnd. 2 Deprtment of Mechnicl Engineering, Fculty of Engineering, Prince of Songkl University, Songkhl 9112, Thilnd. 3 Plm Oil Products nd Technology Reserch Center, Fculty of Agro-Industry, Prince of Songkl University, Songkhl, 9112, Thilnd. * Corresponding uthor, e-mil: sursk_unrung@hotmil.com Received dte : 2/4/13 Accepted dte : 8/11/13

2 96 Ksetsrt J. (Nt. Sci.) 48(1) After neroic tretment, the iogs effluent hs drk rown color with high orgnic mtter (COD) nd some phenol; hence, further tretment is needed. The rown color in plm oil mill effluent is the result of the decomposition of plnts cells such s phenolic compounds (tnnic nd humic cid) from lignin nd melnoidins from the Millrd rection of crohydrte nd protein, s these cuse the color in the sugr processing (Zhrim et l., 9). The ioremedition of color from industril wstes hs een studied y using vriety of microorgnisms such s Lctocillus plntrum (Limkhunsuwn nd Chiprsert, 1), Streptomycetes sp. (Zhou nd Zimmermnn, 1993), Scchromyces cerevisie (Aksu nd Donmez, 3) nd Bcillus sp. (Nkjim-Kme et l., 1999; Dwkr et l., 9). Since these microorgnisms re present in the mixed cultures of Super LDD.1 nd Super LDD.2, they would e tested for decoloriztion nd tretment of iogs effluent. Besides iologicl methods, physicl methods re lso pplied for decoloriztion using plm sh, solid wste generted fter the comustion of plm fiers nd plm shells s oiler fuel for stem genertion in the plm oil mill. Plm sh ws reported to successfully remove dyes from textile industry effluent (Ahmd et l., 7; Is et l., 7). The current study imed to decolorize nd tret iogs effluent from plm oil mill y using iologicl nd physicl methods. MATERIALS AND METHODS Microorgnisms nd rw mterils The iologicl method used mixed cultures (Super LDD.1 nd Super LDD.2) provided y the Lnd Development Deprtment, Ministry of Agriculture nd Coopertives of Thilnd, while consortium Super EM culture ws commercilly ville. The rw iogs effluent from plm oil mill (BEPOM) nd plm sh were collected from Green Glory Co., Ltd nd The Southern Plm (1978) Co., Ltd., respectively, Surt Thni province, Thilnd. The required volume of BEPOM ws thwed to room temperture (27 28 o C) efore use. Plm oil mill effluent (POME) ws collected from Lptwee Co., Ltd, Stun province, Thilnd. BEPOM nd POME were determined for chemicl oxygen demnd (COD), totl suspended solids (TSS), totl solids (TS), color, totl nitrogen (TN) nd totl phosphorus. Anlyticl methods COD, TSS, TS, ph nd totl phosphorus were nlyzed in ccordnce with the Stndrd Methods for the Exmintion of Wter nd Wstewter (Americn Pulic Helth Assocition, 1998). Color ws determined using the pltinumcolt stndrd method (Americn Pulic Helth Assocition, 1998) compred to the Americn Dye Mnufcturers Institute (ADMI) method using spectrophotometer (Spectroqunt UV/VIS spectrophotometer Phro 3; Merck Drmstdt, Germny) nd color mesurements were reported in units of pltinum-colt (PtCo). Phenol ws nlyzed following the method descried y Grcì Grcì et l. (). TN ws nlyzed using commercil test kits from Spectroqunt (Merck KGA; Drmstdt, Germny). Selection of the inoculum source nd cultivtion conditions on decoloriztion of iogs effluent from plm oil mill Preprtion of inocul Prior to use s inocul, the two mixed cultures needed to e ctivted s specified y the mnufcturer (the Lnd Development Deprtment, Thilnd). Super LDD.1 of 2. g ws dded into ml wter nd stirred for 1 min, wheres Super LDD.2 of. g ws dded into ml wter nd stirred for min. Super EM ws ctivted y mixing EM with molsses nd wter in the rtio of 1:1:1, respectively, nd then incuting in closed continer for 7 d efore use. Microil count in the inoculum Microil counting in the three inoculum

3 Ksetsrt J. (Nt. Sci.) 48(1) 97 sources ws conducted using the dilution plte countmethod. The smples of Super LDD.1, Super LDD.2 nd Super EM were diluted in the rnge y.8% NCl. Then,.1 ml of dilution ws dropped on plte count gr pltes, then incuted t room temperture (3 ± 3 o C) for 7 d efore counting. Selection of the inoculum source The two sources of mixed cultures (Super LDD.1, Super LDD.2) nd the consortium (Super EM) were tested for their ility to decolorize BEPOM. The inoculum size of 1% (volume per volume; v/v) ws dded into 1 ml BEPOM (nonsterilized) with 1% POME s supplemented nutrients. Ech smple ws cultivted t room temperture (3 ± 3 C) for 7 d under microeroic conditions. Smples were tken every 24 h for 7 d nd determined for color. The inoculum source tht demonstrted higher decoloriztion thn the control (without ny inoculum) ws chosen for further studies. Selection of cultivtion conditions The selected inoculum source ws inoculted into 1 ml iogs effluent (sterilized) with 1% POME s supplemented nutrients. Incution ws conducted under eroic conditions (n qurium pump ws used to supply ir through porous stone diffuser tht ws locted t the se of the rector with n ir flow rte of 2. volume of ir per volume of medium per min, vvm) nd microeroic conditions (no supply ir) t room temperture (3 ± 3 C) for 7 d. The optimum conditions were chosen for further studies. Effect of inoculum size on decoloriztion of iogs effluent from plm oil mill The selected inoculum source ws used to study the effect of inoculum size (, 1, 1 nd %, v/v) on decoloriztion, COD removl nd phenol removl in the 4 ml BEPOM (nonsterilized) without nutrients ddition. It should e noted tht different tch of the BEPOM ws used which hd higher vlues of color, COD nd phenol thn tht used ove in the first experiment. The experiment ws incuted t room temperture (3 ± 3 C) for 7 d under eroic conditions (2. vvm). Effect of ph nd plm sh concentrtion in comined tretment The BEPOM fter tretment with the selected inoculum source with the ph djusted (to ph 4) nd without the ph djusted (ph 9.1; the control) were used in this study. Plm sh ws dded t concentrtions of 1, 3, 6, 9, 12 nd 1%, weight per volume (w/v). The experiment ws crried out on shker (12 rpm) t room temperture (3 ± 3 C). Smples were tken every 1 min for 6 min. RESULTS AND DISCUSSION Chrcteristics of the iogs effluent from plm oil mill, plm oil mill effluent nd plm sh The chrcteristics of BEPOM nd POME were determined nd found to hve vlues for COD of 1,832 nd, mg.l -1, phenol of 29.8 nd 96 mg.l -1, color of 1,633 nd 24, PtCo nd ph t 7. nd 4.7, respectively (Tle 1). Plm sh ws oven dried t 1 C for 24 hr, nd kept t room temperture till used (without size selection). The chemicl composition of plm sh collected from the sme lot used in this study were reported y Noprt (8) s: silicon dioxide (44.84%), luminum oxide (1.12%), clcium oxide (12.1%), mgnesium oxide (3.22%), potssium oxide (4.99%) nd sulfur trioxide (1.66%). Selection of inoculum source nd cultivtion condition on decoloriztion of iogs effluent from plm oil mill The vile count of the mixed cultures mesured in colony forming units (CFU) of Super LDD.1, Super LDD.2 nd Super EM were , nd CFU. ml -1, respectively. These inocul were employed to tret nd decolorize the rw BEPOM under microeroic conditions. Super LDD.1 nd Super LDD.2 showed sustntilly higher

4 98 Ksetsrt J. (Nt. Sci.) 48(1) decoloriztion (2.6% nd 3.1%) thn the control (no inoculum dded) (4.8%) nd Super EM (42.8%), respectively, fter 4 d cultivtion (Tle 2). Therefore, the mixed cultures were selected. The high efficiency of Super LDD.1 ws due to the presence of eroic cellulose decomposing fungi (Corynscus sp., Scytlidium sp., Chetomium sp. nd Scopulriopsis sp.) nd the eroic cteri (Bcillus sp.) s well s ctinomycete (Streptomyces sp.) in the inoculum used (Leungvutiviroj et l., 7). In ddition, the high efficiency of Super LDD.2 resulted from the ctivity of fculttive lcoholic yest (Scchromyces sp.), lctic cid cteri (Lctocillus sp.) nd protein ctolism cteri (Bcillus sp.) (Psd et l., 7). Decoloriztion y Super LDD.2 ws higher thn tht from Lctocillus plntrum SF.6 for plm oil mill effluent (1.9%) (Limkhunsuwn nd Chiprsert, 1) nd Bcillus sp. for molsses wstewter (3.%) under thermophilic nd neroic conditions (Nkjim-Kme et l., 1999). In ddition, it ws lso higher thn tht from Bcillus megterium nd Bcillus cereus for predigested distillery effluent under eroic conditions (33.%) (Jin et l., 2). The selected mixed cultures (Super LDD.1 nd Super LDD.2) were cultivted under microeroic conditions nd eroic conditions. Super LDD.1 exhiited higher COD removl under eroic conditions (33.3%) thn under microeroic conditions (14.3%) fter 4 d cultivtion (Figure 1). For Super LDD.2, the COD removl under microeroic conditions (32.%) ws sustntilly higher thn tht under eroic conditions (28.6%) fter 6 d cultivtion (Figure 1). Tle 1 Chrcteristics of plm oil mill effluent (POME) nd iogs effluent (BE) from plm oil mill. Prmeter BE POME BE+1% POME Before tretment After tretment ph COD (mg.l -1 ) 1,832, 7,33 3,99 TS (mg.l -1 ) 4,34 38, 8,19 - TSS (mg.l -1 ) 2, Phenol (mg.l -1 ) Colour (PtCo) 1,633 24, 4,33 1,9 Totl nitrogen (mg.l -1 ) 2 1, Totl phosphorus (mg.l -1 ) Apprent Color Drk rown Brown Drk rown Drk rown COD = Chemicl oxygen demnd, Ts = Totl solids, TSS = Totl suspended solids, PtCo = Pltinum-colt unit of mesurement from the Stndrd Methods for the Exmintion of Wter nd Wstewter (Americn Pulic Helth Assocition (1998). Tle 2 Decoloriztion of rw iogs effluent from plm oil mill with supplementtion of 1% plm oil mill effluent y two types of mixed cultures nd consortium under microeroic conditions fter 7 d cultivtion. Experiment Decoloriztion (%) fter time period 1 dy 2 dy 3 dy 4 dy dy 6 dy 7 dy Control 28.7± ± ±1. 4.8± ± ± ±2. 1% Super LDD ±1. 44.± ± ± ± ±1. 3.7±1.4 1% Super LDD.2 3.1± ± ±1. 3.1±1.8.1±1.8.6± ±1.9 1% Super EM 26.2± ± ± ± ± ± ±2.1

5 Ksetsrt J. (Nt. Sci.) 48(1) 99 However, nutrients supplementtion y dding POME (1%) cused n increse in the color, COD nd phenol vlues oth t the eginning nd fter the experiment compred to the control (Tle 1). Therefore, Super LDD.1 nd Super LDD.2 were chosen for further studies without POME ddition. Effect of inoculum size on decoloriztion of iogs effluent from plm oil mill The effect of vrious inoculum sizes (, 1, 1 nd % v/v) of Super LDD.1 nd Super LDD.2 on the decoloriztion of the BEPOM ws studied. For Super LDD.1, the inoculum size t % v/v showed the highest decoloriztion (27.%) under eroic conditions (2. vvm) fter 2 d cultivtion (Figure 2). The inoculum size of Super LDD.2 t % v/v lso gve higher decoloriztion (17.%) thn the other sizes (1., 6. nd 7.%, respectively) under microeroic conditions fter 6 d cultivtion (Figure 2). Although higher in decoloriztion, the Super LDD.1 showed slightly lower COD removl (27.8%) fter 2 d cultivtion under eroic conditions (Figure 3) thn did Super LDD.2 (29.2%) fter 6 d cultivtion under 3 %LDD.1 1%LDD.1 1%LDD.1 %LDD.1 2 COD removl (%) COD removl (%) Aeroic conditions Aeroic conditions Microeroic conditions Microeroic conditions Figure 1 Comprison of chemicl oxygen demnd (COD) removl etween eroic conditions nd microeroic conditions of: () Super LDD.1 nd () Super LDD.2. (Error rs show ± SD. Decoloriztion (%) Decoloriztion (%) %LDD.2 1%LDD.2 1%LDD.2 %LDD.2 Figure 2 Effect of inoculum size (without plm oil mill effluent supplementtion) on decoloriztion of iogs effluent from plm oil mill using: () Super LDD.1 under eroic conditions (2. volume of ir per volume of medium per minute) nd () Super LDD.2 under microeroic conditions. (Error rs show ± SD.

6 1 Ksetsrt J. (Nt. Sci.) 48(1) microeroic conditions (Figure 3). However, in terms of removl efficiency, the Super LDD.1 ws more efficient in the tretment of BEPOM thn Super LDD.2 (13.9% per dy compred to 4.9% per dy, respectively). Mny microorgnisms present in Super LDD.1 nd Super LDD.2 were reported to possess decoloriztion ility. Streptomycetes BW13 decolorized Anthrquinone Blue (27.%) nd Azo-copper Red (73.%) fter 14 d cultivtion y iosorption mechnisms (Zhou nd Zimmermnn, 1993). Lctocillus COD removl (%) COD removl (%) %LDD.1 %LDD.1 1%LDD.1 1%LDD.1 1%LDD.1 1%LDD.1 %LDD.1 %LDD.1 Figure 3 Effect of inoculum size (without plm oil mill effluent supplementtion) on chemicl oxygen demnd (COD) removl of iogs effluent from plm oil mill: () Super LDD.1 under eroic conditions (2. volume of ir per volume of medium per minute) nd () Super LDD.2 under microeroic conditions. (Error rs show ± SD. plntrum showed.% decoloriztion of olive mill wstewter (Lmi nd Moktr, 3). The color removl performed y microorgnisms occurred vi two methods: ioccumultion nd iodegrdtion. In ioccumultion, the microorgnism cn sor dyes into the cell wll nd thus color removl is dependent on iomss nd mss trnsfer effects in the medium, while in iodegrdtion, the dyes re oxidized y the enzymtic system (Silveir et l., 9). The phenol removl efficiency vlues ( %) t ll inoculum sizes tested ( %, v/v) of Super LDD.1 were not sustntilly different (Figure 4). These vlues were higher thn those of Super LDD. 2 ( %) fter 6 d cultivtion (Figure 4). The ility to degrde phenol depended on the strin s well s the Phenolic compounds removl (%) Phenolic compounds removl (%) %LLD.1 %LLD.2 1%LLD.1 1%LLD.2 1%LLD.1 1%LLD.2 %LLD.1 %LLD.2 Figure 4 Removl of phenol in iogs effluent from plm oil mill using: () Super LDD.1 (eroic conditions) nd () Super LDD.2 (microeroic conditions). (Error rs show ± SD.

7 Ksetsrt J. (Nt. Sci.) 48(1) 11 phenol concentrtion. For exmple, Bcillus cereus degrded 99.1%, 1%, 94.8%, 44.3% nd 1.4% phenol from its initil concentrtions of 1,, 1,, 1,, nd 2, mg.l -1, respectively (Bnerjee nd Ghoshl, 1). In ddition, the immoilized Bcillus insolitus could remove more thn % of the 2,4-dichlorophenol using suspended Bcillus insolitus (Wng et l., ). Mny types of eroic cteri re cple of using romtic compounds s the sole source of cron nd energy (Melo et l., ). The typicl pthwy for metolizing n romtic compound is to dehydroxylte the enzene ring to form ctechol derivtive nd then to open the ring through ortho or met oxidtion (Melo et l., ). Bsed on the ove results, Super LDD.1 ws chosen for further study s it exhiited higher decoloriztion, COD nd phenol removl. Effect of plm sh concentrtion nd ph in comined tretment The iologicl treted effluent (ph 9.1) ws further decolorized y the physicl method. An increse in the plm sh concentrtion y 1, 3, 6, 9, 12 nd 1% (w/v) resulted in higher decoloriztion (9., 31.7, 6.3, 61.9, 6.9 nd 76.2%, respectively) t the initil ph of 4 (nd finl ph vlues of 8.4, 8., 8.7, 8.8, 8.8 nd 8.8, respectively) (Figure ) thn with no ph djustment (the control) (3.2, 28.6,.8, 4., 61.1, nd 69.1%, respectively) fter 1 h rection time (Figure ). The results indicted tht cidic conditions enhnced the dsorption of color y the plm sh s the positive chrge domintes on the surfce of the dsorent. Thus, sufficiently high electrosttic ttrction exists etween the positively chrged surfce of the dsorent nd the negtively chrged dye species (Is et l., 7). On the other hnd, the lower dsorption rte t higher ph my hve een due to the relese of OH - ions nd cused ionic repulsion etween the negtively chrged ctive sites of the dsorent (Ahmd nd Hmeed, 9). The finl co-treted effluent smples with plm sh (9 1% w/v nd ph djusted to ph 4) were colorless with n ADMI color vlue elow 3 units which pssed the dischrged effluent stndrd. In the cse of no initil ph djustment, higher plm sh concentrtion (12 1% w/v) ws required to produce vlue elow 3 color units. Moreover, n increse in the plm sh concentrtion resulted in n increse in the phenol removl (.9, 27.9, 4.9, 4.9, 4.9 nd 73.%, respectively) s well s the COD removl (14.3, 21.4, 3.7,., 64.3 nd 64.3%, respectively) with the djusted initil ph t 4 fter 1 h rection time (Figure 6). Without djustment of the initil ph (9.1),, lower vlues were recorded for the phenol nd COD removl thn with n initil ph 4 (Figure 6). Color removl (%) Color removl (%) % Time (min) 1% 3% 3% 6% 6% Time (min) Figure Effect of plm sh concentrtion nd initil ph used for decoloriztion of iotreted iogs effluent from plm oil mill: () Initil ph djustment (ph = 4) nd () No initil ph djustment (ph = 9.1). (Error rs show ± SD. 9% 9% 12% 12% 1% 1%

8 12 Ksetsrt J. (Nt. Sci.) 48(1) Removl (%) Removl (%) Phenolic compounds COD 1% 3% 6% 9% 12% 1% Plm sh (weight per volume) Phenolic compounds COD The results ove indicted tht the ddition of 9 1% plm sh with the initil ph djusted to 4. gve high percentge of decoloriztion nd colorless effluent. In fct, the colorless effluent could lso e chieved without djusting the initil ph providing 12 1% plm sh ws dded. The chrcteristics of BEPOM efore nd fter tretment using the iologicl method with Super LDD.1 for 2 d in comintion with plm sh (9 12% w/v) for 1 h re given in Tle 3. After tretment, the color, phenol nd COD were removed %, % nd %, respectively, nd the ph incresed to Aove ll, the finl effluent ws colorless (Figure 7). The finl vlues of phenol (1 3 mg.l -1 ) nd COD (1 16 mg.l -1 ) met the Dischrged Effluent Stndrd (Ministry of Industry of Thilnd, 1996). CONCLUSION 1% 3% 6% 9% 12% 1% Plm sh (weight per volume) Figure 6 Profile of iologicl tretment method with co-plm sh sorption fter 1 hr rection time: () Phenol removl with initil ph djustment (ph = 4) nd () Orgnic removl (chemicl oxygen demnd; COD) with no initil ph djustment (ph = 9.1). (Error rs show ± SD. Super LDD.1 nd Super LDD.2 were more efficient in the decoloriztion of iogs effluent thn Super EM under microeroic conditions. The optimum inoculum size of oth Super LDD.1 nd Super LDD.2 ws % (v/v), nd Super LDD.1 ws found to e more efficient in decoloriztion nd phenol removl thn Super LDD.2 under eroic conditions without nutrient supplementtion. Tretment y iologicl Tle 3 Removl of color, phenol nd chemicl oxygen demnd (COD) of the iogs effluent from plm oil mill treted y mixed cultures (Super LDD.1) nd 9 1% (w/v) plm sh fter 1 hr rection. Prmeter Biogs effluent from plm oil mill After tretment Stndrd of dischrged effluent ph ±. 9 Color (PtCo) 1, ±6 - COD (mg.l -1 ) 1,8-2, 126.8±3 <1 Phenol (mg.l -1 ) ±1 <1. Apprent color Drk rown Colorless - PtCo = Pltinum-colt unit of mesurement from the Stndrd Methods for the Exmintion of Wter nd Wstewter (Americn Pulic Helth Assocition (1998).

9 Ksetsrt J. (Nt. Sci.) 48(1) 13 Figure 7 Color comprison of iogs effluent from plm oil mill: () iogs effluent nd () effluent fter tretment with Super LDD.1 nd plm sh. method (% Super LDD.1 for 2 d) nd physicl method (9 12%, w/v plm sh for 1 hr) gve 84.7% decoloriztion, 9.8% phenol removl nd 88.9% COD removl. ACKNOWLEDGEMENT This work ws finncilly supported y the Higher Eduction Reserch Promotion nd Ntionl Reserch University Project of Thilnd, Office of the Higher Eduction Commission nd Grdute School of Prince of Songkl University. LITERATURE CITED Ahmd, A.A., B.H. Hmeed nd N. Aziz. 7. Adsorption of direct dye on plm sh: Kinetic nd equilirium modeling. J. Hzrd. Mter. 141: Ahmd, A.A. nd B.H. Hmeed. 9. Reduction of COD nd colour of dyeing effluent from cotton textile mill y dsorption onto moosed ctivted cron. J. Hzrd. Mter. 172: Aksu, Z. nd G.A. Donmez. 3. Comprtive study on the iosorption chrcteristics of some yests for Remzol Blue rective dye. Chemosphere : Americn Pulic Helth Assocition Stndrd Methods for the Exmintion of Wter nd Wstewter. th ed. Americn Pulic Helth Assocition, Americn Wter Works Assocition, Wter Pollution Control Federtion. Wshington, DC, USA. 136 pp. Bnerjee, A. nd A.K. Ghoshl. 1. Phenol degrdtion y Bcillus cereus: Pthwy nd kinetic modeling. Bioresour. Technol. 11: 1 7. Dwkr, V.V., U.U. Jdhv, A.A. Telke nd S.P. Govindwr. 9. Peroxidse from Bcillus sp. VUS nd its role in the decolouriztion of textile dyes. Biotechnol. Bioproc. Eng. 14: Grcì Grcì, I.P.R., J.L. Jimĕnez Pĕn, A. Bonill Vencesld, M.A. Mrtìn Mrtìn Sntos nd E. Rmos Gmez.. Removl of phenol compounds from olive mill wstewter using Phnerochete chrysosporium, Aspergillus niger, Aspergillus terreus nd Geotrichum cndidum. Proc. Biochem. 3: H-Kittikul, A., P. Prsertsn, K. Srisuwn, S. Jitunjerdkul nd W. Thonglimp Oil recovery from plm oil mills wste wter, pp Proceeding of Oil Loss Prevention in Plm Oil Industry. Deprtment of Industry. Surt Thni, Thilnd. Is, M.H., L.S. Lng, F.A.H. Asri, H.A. Aziz, N.A. Rmli nd P.A.J. Dhs. 7. Low cost removl of disperse dyes from queous solution using plm sh. Dyes Pigm. 74: Jin, N., A.K. Minoch nd C.L. Verm. 2. Degrdtion of predigested distillery effluent y isolted cteril strins. Indin JEXP. Biol. 4: Lmi, A. nd H. Moktr. 3. Fermenttive decolouriztion of olive mill wstewter y Lctocillus plntrum. Proc. Biochem. 39: 9 6.

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