外文原文-采用连续生物处理(厌氧好氧)对SEKA造纸纸浆工业废水进行处理.pdf

Sequential anaerobic aerobic biological treatment of Dalaman SEKA Pulp and Paper Industry effl uent Ulas Tezel a Engin Guvenb Tuba H Ergudera Goksel N Demirera aMiddle East Technical University Department of Environmental Engineering Ino nu Bulvari 06531 Ankara Turkey bCivil and Environmental Engineering Marquette University PO Box 1881 Milwaukee WI 53201 1881 USA Received 13 June 2000 received in revised form 24 January 2001 accepted 29 January 2001 Abstract In the pulp and paper industry lignin and other color compounds are removed by chemical agents in bleaching process Use of chlorine based agents results in production of degradation products which include various chloro organic derivatives Since these new compounds are highly chlorinated they cause a problem in the treatment of pulp and paper industry wastewaters Chemical precipitation lagooning activated sludge and anaerobic treatment are the processes used for treating pulp and paper effl uents Furthermore a combination of these processes is also applicable In this study the effl uent of Dalaman SEKA Pulp and Paper Industry was examined for its toxic eff ects on anaerobic microorganisms by anaerobic toxicity assay Additionally this wastewater was applied to a sequential biotreatment process consisting of an upfl ow anaerobic sludge blanket as the anaerobic stage and a once through completely mixed stirred tank as the aerobic stage Results indicated that 1 Dalaman SEKA Pulp and Paper Industry wastewater exerted no inhibitory eff ects on the anaerobic cultures under the studied conditions and 2 application of a sequential biological anaerobic aerobic system to treat the Dalaman SEKA Pulp and Paper Industry wastewater resulted in approximately 91 COD and 58 AOX removals at a HRT of 5 and 6 54 h for anaerobic and aerobic respectively 2001 Elsevier Science Ltd All rights reserved Keywords Pulp and paper industry Upfl ow anaerobic sludge blanket UASB Completely mixed stirred tank CMSTR Anaerobic Aerobic 1 Background The main processes that are involved in the manu facture of paper are debarking pulping separation of pulp from cooking liquor bleaching stock preparation and making the fi nal paper product In the bleaching process lignin and other color compounds are removed by chemical agents The oxidation agents used for bleaching central to the industry are chlorine based such as Cl2 ClO2 hypochlorite NaOCl etc There are also oxygen based oxidation agents such as H2O2 Na2O2 O3 etc under consideration but they are far from wide scale applications Use of chlorine based agents results in the production of degradation products which include various chloro organic derivatives The technology of the bleaching process and in mill control is under continuing improvement But yet treatment of bleaching process wastewater externally is necessary 1 Thus treatment of pulp and paper industry effl uents containing chlorinated compounds is still of vital importance The general characteristics of the pulp and paper industry effl uent can be listed as 1 high lignin content 2 high absorbable organic halide AOX concentration due to the bleaching process 3 color 4 low biode gradability which is indicated by their high chemical oxygen demand to biochemical oxygen demand ratios COD BOD often in the range of 4 6 and 5 potential toxicity problems The typical treatment processes for pulp and paper effl uents are chemical precipitation lagooning activated sludge and anaerobic treatment When the economic concerns and the rate of treatment are considered anaerobic treatment can off er a viable treatment option for these wastewaters Many researchers studied removal of organic com pounds from pulping effl uents In terms of chemical 0956 053X 01 see front matter 2001 Elsevier Science Ltd All rights reserved PII S0956 053X 01 00013 7 Waste Management 21 2001 717 724 Corresponding author Tel 1 414 288 1607 fax 1 414 288 7521 E mail address engin guven marquette edu E Guven precipitation depending on the coagulant and studied wastewater unbleached kraft effl uent bleached kraft effl uent neutral sulphite semi chemical etc various removal effi ciencies 20 85 for AOX 20 91 for COD and 36 100 for color were achieved 2 12 A three stage chemical treatment using FeCl3 H2SO4 and alum in successive stages resulted in a total BOD reduction of 50 with a turbidity reduction greater than 82 and a practically colorless effl uent All other single coagulants or combinations of chemical coagu lants resulted in lower BOD reductions 13 It was also reported that the percent AOX reduction by combined chemical and biological treatment ranged from 53 to 59 depending on the operating conditions of the biological treatment process 14 In an aerated lagoon 37 of the totally bound chlorine and 24 of the non purgeable organic carbon NPOC were removed 15 In another study 32 AOX removal was achieved in treatment of conven tional mill wastewater by an aerated lagoon system 16 The performance data for aerobic facultative and anaerobic ponds are summarized for pulp and paper wastewaters in Table 1 17 In an activated sludge plant treating kraft mill waste water 40 50 AOX and COD removals were achieved In another mill which had a BOD loading of about seven times higher than the former a COD reduction of 34 and an AOX removal of 20 30 were achieved 18 A 70 COD removal in a UASB reactor was reported 19 Biological AOX removal was studied for 2 years and 30 35 removal for aerobic 40 45 for anaerobic and 50 55 removal for anaerobic aerobic sequential treatment were observed 20 When two reactor systems as two stage bioreactors in series fol lowed by a settler with solids recycle were studied one system was operated in an anaerobic aerobic mode NA and the second in an aerobic mode AA How ever no obvious diff erence between NA and AA sys tems 57 and 59 removal of AOX respectively was obtained 1 Zitomer and Speece 21 stated that the ability of an aerobically activated sludge process to reduce toxicity is highly variable even when effi cient suspended solids and BOD removal is achieved Anaerobic reactor followed by aerobic reactor is more successful at reducing toxi city Reductive dechlorination may occur in anaerobic stage and produces less chlorinated organics These organics may be further biotransformed in conventional aerobic stage 21 In this study a pulp and paper industry effl uent from Dalaman SEKA Pulp and Paper Industry was examined for its toxic eff ects on anaerobic microorganisms by anaerobic toxicity assay Addition ally this wastewater was applied to a sequential bio treatment process consisting of an UASB as the anaerobic stage and a once through CMSTR as the aerobic stage 2 Materials and methods 2 1 Inocula 2 1 1 Municipal anaerobic digester sludge MADS Municipal anaerobic digester sludge MADS which was used in batch experiments was obtained from anaerobic digesters of the Ankara Municipal Waste water Treatment Plant Turkey The digesters are cylindrical in shape and made of concrete with a reten tion time of 14 days The average fl ow of sludge from primary thickeners to each digester is 805 m3 day The pH in the digesters ranges between 7 00 and 7 70 Before using the sludge was thoroughly mixed and fi ltered through a screen with a pore size of 1 mm Where a more concentrated sludge was needed it was settled in an Imhoff cone for 24 h and the sludge remaining under the supernatant was used 2 1 2 Anaerobic granules Anaerobic granules which were used in the UASB reactors were obtained from the wastewater treatment plant of Tekel Pasabahce Factory Istanbul Turkey The organic loading rate of the treatment plant is 30 kg COD m3 day with a fl ow of 60 m3 day The pH of the reactor ranges between 6 0 9 0 2 1 3 Aerobic cultures Aerobic cultures were obtained from the aeration tanks of the activated sludge units of the Ankara Municipal Wastewater Treatment Plant Turkey with a sludge age and organic loading of 2 8 days and 165 000 kg BOD5 day respectively Table 1 Performance of lagoon systems in treatment of pulp and paper wastewaters Lagoon confi gurationArea acres Depth ft Detention day Loading lb acre day BOD5removal Aerobic facultative845 01015787 Anaerobic ponds716 018 434750 Aerobic anaerobic25205 51362894 718U Tezel et al Waste Management 21 2001 717 724 2 2 Pulp and paper effl uent Pulp and paper effl uent PPE was obtained from Dalaman SEKA Paper Industry Turkey During the entire research PPE was taken twice from the industry PPE 1 PPE 2 PPE 1 had a COD of 450 500 mg l and volatilesuspendedsolids VSS concentrationof 51 4 2 mg l whereas PPE 2 had a COD of 5500 6000 mg l and VSS of 820 28 3 mg l Before using in the continuous reactor experiments the PPE was thor oughly mixed strained through a 175 mm sieve and stored in a 10 liter glass container 2 3 Preparation of basal media To supply necessary micro and macro nutrients and alkalinity basal media BM was used in the batch experiment The composition of the BM is as follows concentrations of the constituents are given in para nthesis as mg l NH4Cl 1200 MgSO4 7H2O 400 KCl 400 Na2S 9H2O 300 CaCl2 2H2O 50 NH4 2HPO4 80 FeCl2 4H2O 40 CoCl2 6H2O 10 KI 10 MnCl2 4H2O 0 5 CuCl2 2H2O 0 5 ZnCl2 0 5 AlCl3 6H2O 0 5 NaMoO4 2H2O 0 5 H3BO3 0 5 NiCl2 6H2O 0 5 NaWO4 2H2O 0 5 Cysteine 10 NaHCO3 6000 22 2 4 Analytical Methods 2 4 1 Suspended solids SS volatile suspended solids VSS total solids TS and total volatile solids TVS SS VSS TS and TVS were measured according to Standard Methods 2540 23 2 4 2 pH pH in samples was measured by a bench top pH meter Jenway Ltd Essex UK and a general purpose pH electrode Cole Parmer Niles IL USA 2 4 3 Gas production Gas production in serum bottles was measured using a gas replacement device consisting of a 50 ml burette with a water reservoir A needle connected via latex rubber tubing to the burette was inserted through the serum bottle stopper and the volume of the water dis placed from the cylinder by gas was recorded The collected gas was vented after the measurement 2 4 4 COD COD concentrations were determined according to an EPA approved reactor digestion method 24 A Hach COD reactor and a Hach DR 2000 spectrophotometer operated at a wavelength of 620 nm were used COD detection limit was 18 mg l Therefore effl uent COD values of 0 18 mg l corresponded to 100 COD removal in calculations 2 4 5 Volatile fatty acids VFA and bicarbonate alkalinity Volatile fatty acids and bicarbonate alkalinity were measured according to the titration procedure described by Anderson and Yang 25 2 4 6 Color Color of the samples were measured by using a Hach DR 2000 spectrophotometer operated at a wavelength of 455 nm 24 2 4 7 AOX The AOX concentration of the samples was measured by an analytical instrument containing boat control control furnace coulometer cell and micro coulometer Euroglas units and a printer Kipp 35 2 101 2 Smith OD Stein RM Adams CE Analysis of alternatives for removal of suspended solids in pulp and paper mill effl uents TAPPI Environmental Conference Denver Col 1975 85 3 Nicolle FMA Shamash R Nayak KV Histed JA Lime treat ment of bleachery effl uent Pulp Paper Canada 1977 78 T210 4 Dorica J Wong A Detoxifi cation of linerboard effl uents using physical chemical techniques Pulp Paper Canada 1979 80 T80 5 Knocke WR Bhinge D Sullivan E Boardman GD Treatment of pulp and paper wastewaters for potential water reuse Proceed ings of 41st Purdue Industrial Waste Conference Lafayette Ind 421 1986 6 Bennett DH Reeser D Cambell AG Falter CM Pretreatment of CTMP effl uents by lime to reduce resin acids sulphite and toxi city TAPPI Environmental Conference Charleston S C 199 1988 7 Milstein O Haars A Majcherczk A Trojanowski J Tautz D Zanker H Hutterman A Removal of chlorophenols and chlor olignins from bleaching effl uent by combined chemical and bio logical treatment Wat Sci and Tech 1988 20 161 8 Almemark M Ekengren O Physical chemical treatment of bleach plant effl uents with emphasis on chemical coagulation 5th Int Symp On Wood and Pulping Chemistry Raleigh NC 27 1989 9 Barton DA Drake E Hall TJ Bousquet T Physiochemical treatment of bleach plant fi ltrates and fi nal effl uents for the reduction of chlorinated organic compounds TAPPI Environ mental Conference Richmond Va 821 1992 10 Beulker S Jekel M Precipitation and coagulation of organic substances in bleachery effl uents of pulp mill Wat Sci and Tech 1993 27 193 U Tezel et al Waste Management 21 2001 717 724723 11 Chernoberezhskii Yu M Barisheva IA Tikhonava TV Coagu lation treatment of sewages of suphite pulping mills by pre hydroyzed forms of aluminum 4th IAWQ Symp On Forest Industry Wastewaters Tampere Finland 1993 12 Savolainen M Oxidative precipitation and air fl otation of pulp and paper mill effl uents with ferrous sulphate and hydrogen per oxide fennotriox 4th IAWQ Symp On Forest Industry Waste waters Tampere Finland 1993 13 Nemerow N L Liquid waste of industry theories practices and treatment Addison Wesley Pub Com 1971 14 Francis DW Turner PA Wearing JT AOX reduction of kraft bleach plant effl uent by chemical pretreatment pilot scale trials Wat Res 1997 31 2397 15 Bryant CW Amy GL Alleman BC Organic halide and organic carbon distribution and removal in a pulp and paper wastewater