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Tap chi Khoa hgc Tnrang Dai hoc Can Tho Phdn A Kboa hgc Tu nbien Cong nghe va Moi Iruang 29 (2013) 45 50 Tap chi Khoa hgc Tru''''dng Dai hoc Can Thĉ website sj ctu edu vn ANH HU^dNG CUA THCH GIAN LlTU N[.]
Tap chi Khoa hgc Tnrang Dai hoc Can Tho Phdn A Kboa hgc Tu nbien Cong nghe va Moi Iruang- 29 ( Tap chi Khoa hgc Tru'dng Dai hoc Can Thc^ website: sj.ctu.edu.vn ANH HU^dNG CUA THCH GIAN LlTU NUdC 0EN HIEU QUA KHtT CHAT HUtJ CO VA BAC TINH BAN MANG CUA HE THONG SPONGE MEMBRANE BIOREACTOR XU* LY NU6C THAI AO NUOI CA TRA Le Nguyen Tuylt Nguyen' va Bui Xuan Thanh' ' Khoa Mdi trudng, Trudng Dai hgc Bdch khoa Thdnh phd Hd Chi Minh Thdng tin chung: Ngdy nhdn: 23/05/2013 Ngdy chap nhgn: 24/12/2013 rule: Effects of hydraulic retention time on organic removal and membrane fouling in sponge membrane bioreactor treating catfish pond watewater Tir khda: Bi sinh hgc mdng cd gid thi Sponge (Sponge MBR), thdi gian luu nudc (HRT), dp sudt chuyen mdng (TMP), nudc thdi ao nudi cd tra vd su bdn mdng Keywords: Sponge membrane bioreactor (Sponge MBR), hydraulic retention time (HRT), Transmembrane pressure (TMP) catfish pond wastewater and membrane fouling ABSTRACT Performance of the sponge MBR with a moving-cube sponge medium (20% v/v) was evaluated at different HRT for removing organic from catfish pond wastewater and membrane fouling The sponge MBR was operated at different HRT values of 8, and hours, corresponding to membrane fluxes of 5, 10 and 20 L/m-.h, respectively The results showed that the COD removal efficiencies were maintained at 94%, 93% and 87% at a HRT of and hours, respectively, indicating that HRT affected the permeate quality in an inversely proportion with HRT (h) This fouling rate M'as defined by the increase of the TMP according to operating time (kPa/day) The freely movement of sponges inside the reactor could reduce membrane fouling due lo sweeping of sponge media on membrane surface and attaching ofMLSS on the interior and surface of sponge media TOM TAT Hi thdng Sponge Membrane Bioreactor (Sponge MBR) sir dung gid the dgng hong xdp di ddng gid the chiem 20% thi tich be phdn irng, duac vdn hdnh d cdc thdi gian luu nudc (HRT) khdc nhdm ddnh gid hiiu qud xu ly chdt hiru ca vd dgc tinh bdn mdng ciia he thong xu ly nudc thdi ao nudi cd tra Hi thdng sponge MBR dugc vgn hdnh a HRT 8, vd gid tuang img vol thdng luang 10 va 20 L/m^.h Hieu qud xir ly COD dgt 94% d HRT vd gio, d HRT gid chi dgt 87% Kit qud ndy cho thdy su thay ddi HRT ldm dnh hudng din hieu qud xir ly COD cua he thdng sponge MBR Ngodi tdc dg bdn mdng cdng tdng HRT cdng gidm Tdc bdn mdng dugc tinh todn bdng biin thiin ciia dp sudt chuyen mdng (TMP) theo thdi gian van hdnh he thong (kPa/ngdy) Cdc gid thi chuyin dgng tu be phdn irng giup gidm bdn mdng su eg sdt ldm sach bi mdt mdng vd su bdm dinh biin hogt tinh tren bi mgt vd ben gid the GIOflTHipU Ap dung phuong phdp xic ly sinfa hpc cac chit huu ca va dinh dudng frong nudc thai ao nudi cd fra dugc xem la phii hgp vi nudc thai phin d nhiera chu ylu la cic chat de phan hiiy sinh hoc tir thuc in thira ciia ci, chat bii tiet cua cd Phuang phdp sinh hpc phd biln la bim hogt tinh, loc sinh hpc, hd sinh hpc va dat nggp nudc nhdn tao Tuy nhien, cdc he thong frln ddi hdi phii CO dien tich xay dyng cdng trinfa rdng rai bi gidl han bdi thdi gian van hanh vl cdn phy thudc vio thdi gian xu ly nudc ao nudi ci sau thu Tap chi Kboa hgc Tnr&ng Dai hgc Cdn Tha Phdn A Khoa hgc Tu nhien Cong ngh? vd Moi iru&ng: 29 (2013): 45-SO hoach ci dl tiep tuc vu nudi ki tiep Trudc thyc frang dd thi he thdng nhd gpn hieu qui, linh hogt va cd Ihl xir ly liln tuc frong sudt vy nudi dugc dl xudt la h? thdng sinh hpc raang (Membrane Bioreactor - MBR) Cdng nghe MBR cd nhiiu uu diem hon so vdi biin hogt tinh thdng tfaudng LTu diem vugt trpi ciia MBR li chit lugng nudc thii sau xu ly rat cao co thi tai sir dung nudc thai, dien tich h | thong xii ly nhd gpn, thdi gian luu bim dai, lugng biin sinh thap vd van hanh linh hoat (Visvanathan et al 2000) Tuy nhien, han chl ciia cdng nghe MBR Id vdn dl bin mang Vi the, da cd nhilu nghiin ciiu nhim phit friln cdc uu diim cua cong nghi MBR vio linh vyc xu ly tai sii dung nudc thai dl gop phin vao viec sii dung hi|u qud vi till kilm tdi nguyin nudc Mot so nghiin ciiu phat friln cdng nghe MBR bdng cdch kit hop vdi cdc logi gid tfal la liing gpi Id sponge MBR Sorabatsompop et al (2006) di nghiin ciiu so sanh hieu qui xii ly ciia cdc he thdng MBR vdi cde logi gii the khic vd dilu kiln van hanh khic (HRT, MLSS) Kit qua thu dugc hieu suit xu ly ciia he thing sponge MBR la cao han so vdi MBR thdng thudng vi MBR vol gia thi cd dinh, o HRT 8, 6, va gid hieu suit xii ly chit htiij CO dat 97-98% Diiu cho thiy cdng nghe MBR vdi gia thi sponge di dpng di phat huy tac dyng tdng cudng hi|u qua xu ly ciia he thing MBR thong thudng Nghien ciiu ciia Jamal Kfaan vd ctv (2011) cung so sdnfa hi|u qud xii ly ciia MBR vdi sponge MBR Kit qua cho thay ring failu qua loai bd cic TN va TP sponge MBR la 89% va 58% cao ban frong MBR thdng thudng Tir kit qui tren suy ring sy hi|n diln ciia gia thi giiip sinh khoi phit friin phiie tap bin frong cic gia thi sponge frong bi MBR giiip cai thien kha nang xir ly TN vd TP nudc thdi Basu vi Huck (2005) di nghiin cim dnh hudng ciia gid thi frong he thing MBR nhiing chim Trong nghiin cuu tap trung dinh gii tie dp bin ming vd chit lugng nudc thai sau kfai qua raang Kit qua li tic dp bin raang ting gip ddi khdng cd cac gii thi frong bl Tic gii cung cho rdng cac gia thi tdng cudng cp nia bi mil mdng vi giiip tangfrirdngcac ming sinh hpctren cic gia thi, cai tfailn hiiu qui xii ly ciia h | thing MBR _ HI thing sponge MBR Id mdt he thing MBR kit hgp gia thi sponge chuyin ddng la lung frong hon hgp biin hogt tinh tgo diiu kiln cho loai hinh ting trudng bim dinh ciia sinh khii phit friin song song vdl sinh klidi tdng frudng lo liing bi bim hoat tinh va ndng phdn tach chit Idng/rin cua ming Ipc U'u diem cua sponge MBR la ning dp sinh khoi cao giup he thdng van hinh d tii trpng cao gidm dugc diln tieh bl phin iing vd tang hiiu qui xii ly ciia he thdng (Leiknes et al, 2001, Thanh va ctv., 2009) Cac gid the sponge cdn giiip giam ban mdng sy bira dfnh ciia cic ehit la liing va chat keo lln sponge vd sy cp sat giiia sponge vdi bi mat mdng lam gidm ldp bdnh bim frln be mit mdng (Chae et al, 2004; Ngo vd ctv., 2006; Guo et al, 2009) Muc tieu ciia nghiin cim niy nfadm danh gii su anh hudng ciia thoi gian luu nudc din hieu qua xir Iy chat huu ca vd die tinh bin mang ciia he thing sponge MBR xii ly nudc thii ao nudi ci fra PHU'CfNG PHAP NGHIEN ClTU 2.1 Vgt lif u nghiin ciiu Nudc ao nudi ca tra dugc lay tir ao nudi ci tra d dpe bd Nam rgch Tdm Bdt thudc dia bin Thanh phi Long Xuyln, tinh An Giang Ao nudi co dien tich 800 ra\ dp sau 1.5-2 ra, mat dp tha ca la 30 con/m^, trpng lugng cd luc bdt diu liy nudc ao lim nghien ciiu la khoing 200-500 g/con va luong thirc in la 30 kg/ngdy Nhung sau he thing van hanh dugc mpt thdi gian thi tir ngdy thii 88frddi lu lut (cuii nam 2011) Iran vdo ao nin he thing dugc van hdnh vdi nudc thii ao nuoi ca fra nhan tao Nudc thai nhdn tao dugc pha chi tir nudc cip, thiic dn viin cila ci tra va NH^Cl Nlng dl nhiira trung binh ciia nudc thdi ao nudi ca fra va nudc thai nhin tao (cd ciing tdi lupng nhilm) frong nghien ciiu; TSS 200*82 mg/L, COD 66± 29 mg/L, NH4+ 10*5 rag/L, N02- 0.65*0.81 mg/L NO3- 0.25* 0.45 mg/L vdTPli 1.69*1.19 mg/L 2.2 Mo hinh hf thong sponge MBR Bi sponge MBR hoat dpng vdi thi tfch hihi dyng Id 40 L vd I module mang nhiing chun loai micro-membrane (Motimo China) Kich thudc module mdng 210 mra x 450 mm vd Id lpc qua mang la 0.2 yra H | thing mang hoat ddng theo chu ky phiit lpc/2 phiit nghi Thdi gian luu biin (SRT) dugc kiim sodt Ii 30 ngiy d cac giai doan van hinh Ndng dp oxy hda tan (DO) dupe tri frong be sponge MBR d raiic ldn hon rag/L bing he thing phan phii vi may thoi co luu lupng tii da 75 L/phiit (CO-Resun) Ap suit chuyin mang (TMP) ciia sponge MBR dygc ghi nhdn boi ding hi ap (Pressure gauge) Khi TMP dat toi 0.4 bar thi bom riia ngugc (Bluewhite C-660P, USA) se hogt ddng de loai bd cac ldp biin bim frln bl mat mang Bom riia ngugc cd luu lupng QRN = 2Q Nudc rira ngugc li nudc sgch chiia sin frong thiing (Hinh 1) Tap chi Khoa hgc Tnr&ng Dai hgc Can Tho Phan A: Khoa hoc Tir nhien Cong ngh? va Moi tnrang- 29 (2013) - 45-50 Auto-valve B»ekw«h pump Level control l«r Nud-c thai vao l;:^"! -^^ = ^ C ^ = = @ ^ Niro'c tha thai - • • sau xirly Suction pump Hinfa 1: So* dd nguyen Iy boat dpng cua he thong Sponge MBR 2.3 Gia the sponge Gid thi dgng xdp (sponge) dugc lira bdng chdt lieu Polyurethane cd sdn ngoai thi frudng vdi ti frpng 18.2 kg/ra^ vd dugc edt thdnh hinh lap phuang cm X era X cm, dugc cho di chuyin ty bl MBR nhd vao lyc ndng ciia bpt Gia the dang sponge di dpng lam bang chat lilu Polyurethane di dugc lya chpn cho failu qua xii ly tdi im theo nghiin ciiu cua Guo et al (2010) Kich thudc ciia gid thi sponge d cm x cm x cm ciing dugc Tien va ctv (2010) nghiin ciiu vi dua kit lugn mang Igifaieuqua xir ly tdt nhit Bun nudi cay ban ddu cho bl sponge MBR la biin dugc lay tir bl bim boat linh tfadng thudng (70%) v/v) va biin day ao ca tra (30% v/v) Nong dp MLSS ban diu cua sponge MBR la xap xi 6000 mg/L Sau he thong MBR hogt dpng thich nghi vdi dilu ki?n vgn hanh frln, hieu qud xii ly COD ciia he thong on dmh, thi cho thim gid the sponge vdo bl MBR vdi sd lugng bdng 20% the tich hiiu dung ciia bl MBR 2.4 Dieu kiln vdn faanh Trudc tiln, he thdng MBR dugc van hdnh thich nghi frong dilu kiln thdng tfaudng (kfadng co sponge) d HRT gid nudc thai ao nudi ca fra vdi ndng dp d nhilm nfau muc I Sau 26 he thing MBR di thich nghi tit vdi dieu kiln van hanh (thdng qua sy dn dinh ciia fai|u suit xii ly COD ciia h? thing MBR) Sau he thong hogt dpng thich ngfai ta thyc hiln thi nghiem chinh Bl MBR dugc them vdo 20 % gia thi sponge so vdi thi tich bi di tien hanh nghiin cim frai qua giai dogn van fainh vdi cac HRT va gid tuong iing thdng lugng la 10 vi 20 L/m-.h, vi luu lugng ddng Id 120, 240 va 480 L/ngiy vdi thdi gian luu biin (SRT) Id 30 HI thong sponge MBR dugc van hanh vdi cac HRT 8, vd gid 2.5 Phuong phdp phan tich Phuang phdp phin tich COD theo tiiu chudn APHA (1998) Phuong phdp phdn tich MLSS frong sponge: Say kho cdc sir d lOS^C din khii lugng khdng ddi va sau dd dem cdn ta dugc mo (mg) Liy 10 milng sponge khdi be sponge MBR, vd that sgch bim frong sponge vdo 100 mL nudc cit Cho nudc biin vdo cdc sir, dem nung d I05°C din khdi lugng khdng ddi Cin khoi lupmg sau nung ta dugc rai (mg/I Osponge), mi frong bl sponge MBR sii dyng 1000 milng sponge va tfai tich hiiu dung ciia bl la 40 L nen suy ra; MLSS = (mi - mo) X 100/40 = a (mg/L) KET QUA VA THAO LU^N 3.1 Hieu qua xir ly COD Ndng dp COD diu trung binh tuong iing vdi cac HRT d 8, vd gid la va 11 mg/L Hieu suit xir Iy COD ciia he thing sponge MBR fri rairc trung binh 94% 93% van hinh vdi HRT va gid, nhung chi dgt 87% d HRT gid Khi he thong van hanh vdi HRT va gid co hieu suit xii ly luong duong nhung HRT hon kem rapt niia la vi frong bl MBR ca chi phan buy chdt hiJu CO CO frong nudc thai phan ldn nhd vio biin boat tinfa, rad ndng dp MLSS ban dau ciia sponge MBR Id xap xi 6000 mg/L Do van hanh he thdng vdi HRT gid thi hieu qui xii ly vdn cao Phdn A Khoa hoc Tu nhien, Cdng nghi vd Mdi trucmg: 29 (2013): 45.^1 Tap chi Khoa bgc Tnr&ng Dai hgc Cdn Tha Nhung van hanfa he thdng vdi HRT d gid thi HRT qud ngdn khdng du thdi gian cho cac vi sinh vat frong biin hogt tinh va frong gid thi tiiu thy vi phan huy cac chdt hiiu co nudc thii dau vio he thdng Qua kit qui frln ta thiy ndng dp COD frong nudc thii sau xir ly dgt QCVN 11:2008/BTNMT (COD = 50 mg/L), QCVN 08: 2008/BTNMT (COD = 10 mg/L) vd ed cac Ulu chuin vl tai sir dyng nuoc thai ciia US EPA (< 20 mg/L) [QCVN 08:2008/BTNMT, QCVN 11:2008/BTNMT, US.EPA (2004)] Cote va crv (1997) cung da dua kit qua ndng dp COD frong nudc thii sau xii: ly qua he thdng MBR sgi rdng fri d raiic dudi 16 mg/L sau qua giai doan vin hdnh h | thdng vdi HRT thay ddi tir din 24 gid Cdn ddi vdi nghiin ciiu ciia Guo et al (2008) thi tim dugc hiiu suit xti ly COD dgt frln 97% Mat khac, ta thiy dugc rapt im thi Idn cOa h^ thdng sponge MBR Id it bi sdc tii COD dong vao cd biin dpng (70*12 mg/L) nhung COD dong luon dn dinh (ddng ciia ba giai doan van hanh vdi HRT khac c6 ndng trung binh 6.33± mg/L), he thdng van thich nghi tdt ndng dp COD ddu vao biin dii (Hinh 2) COD-ra HRT=4h •• COC'-' HBT=8h ~^0' ffi' Hinfa : Hifu suat xir ly C O D d cac giai doan van h a n h HRT=Ih tii « f i ^ V » I! 16 ae 33 39 47 3.2 B^c tinh ban mang cua hi thong sponge MBR Tdc dp bdn mang dugc xac dinfa bdng xu hudng sy gia tang tdn that ap lyc qua ming theo thdi gian (dAP/dt) Hinh cho thiy tdc dp bdn raing la 0.0437 0.2046 vi 0.8853 kPa/ngay frrong ling vdi cac thdng lugng Id 5, 10 va 20 L/m'.fa Tdc dp bin mang thip nfadt d thong lugng L/m^.h (HRT gid) CO gia fri la 0.0437 kPa/ngiy Kit qui cho kit lugn la thong lugng tang ti 11 thuan vdi tic dp bin ming cua he thing sponge MBR, hay noi cdch 60 « 61 92 ye 135 110 116 V2 Wi ^iS !i6 151 161 Th«1fllHiInflty) khdc la tdc dp bin mang tang HRT gidm, dilu gidng vdi kit luin cOa mdt sd nghiin ciiu tmdc diy (Cho el al, 2005; Kok-Kwang el al 2011) Thdng lugng cing tdng thi tic dp bin mang cang tang Id biin sinh hpc frong bi MBR bam vdo va bjt kin Id mang lira cho tdn thdt ap lyc qua mang cang ldn Khi tdc dp bin mdng cham thi si lin rira mang ft, giiip cho tuii tho cua ming ting cung nhu gidm dugc chi phi diu tu cho thay moi mang va hoa chat sir dyng cho vile riia sgch mang 05 IMH O10LMH A20LMH ^ Rira ngugc true tuyen 50 Hinh 3: Xu hudng TMP tfaeo £ thdi gian ciia he thong sponge £.-in MBR t = 20 10 20^^ 30 Thoi gian (ngay) Tgp ehi Khoa hoc Tnr&ng Dgi hgc Cdn Tho Pban A Khoa hgc Tif nhien Cdng nghe vd Mdi Iruang- 29 (2013/: 45-50 Khang sponge HRT=«i HRT=2h 16CO0 Hinfa 4: Ham lugng MLSS ? i»« sponge so vdi tdng MLSS I " ' ^ bi sponge MBR *" Thai glin (ngay) Hinh the hien ham lugng MLSS frong sponge so vdi tong MLSS frong bi sponge MBR chiim tii 20-70% Ti 11 MI;SS frong sponge/Tong MLSS cd xu hudng ling dan theo thdi gian van hanh Kit qud ndy cfao thiy uu diem cua sponge frong bl MBR la MLSS tip frung frong sponge cang nhieu lam eho MLSS bim lo Iiing cdng it Iai vd sponge cp sdt vdi bl ragt mang tao dieu kien giam dugc bdn mang (Hinh 5) Basu vd Huck (2005) da nghiin ciiu dnfa hudng ciia gii tfal he thong MBR nhiing chim Trong nghien cim tap trung dinh gid tdc dp bin radng vd chat lugng nudc thii sau qua ming Kit qua dupe tim thiy la tdc dp tic mang tdng gdp ddi kfadng cd cac gii thi frong bi Cac tic gii ciing cho ring cac gid tfal tang cudng cp rOra bl mat mang vd giiip tang frudng cac ming sinh hpc tren cdc gia thi, cii thien hieu qud xir ly ciia he thdng MBR Hinh 5: Bun tren be mat mang kfadng cd sponge (A) va kbi CO sponge (B) | | i l \ f t | { L KET LUAN Kit qui cho tfaay hi|u qud xii ly COD ciia he thing sponge MBR o HRT va gid dat 94% va 93%; cdn d HRT gid chi dat 87% Khd nang xii ly COD ciia he thing hieu qua vdi thdi gian luu nudc va gid Thdi gian luu nudc lien quan din thong lugng ciia h | thdng sponge MBR vi inh huong ragnh den tdc dp bin mdng Toe dp ban ming ti Ie nghich vdi thai gian luu nudc Gid thi sponge thim vao bl MBR giiip lim giam duoc bin ming nhd vao sy bim dinh ciia sinh khii len bi mat sponge, di vdo sponge yd viec chuyin dpng ty frong he thdng tao dilu kiln cp sdt giua gia thi sponge va bi mat mang din din logi bd Idp mang vi sinh v|t fren be mat mang Nudc thai ao nudi cd sau xu Iy cd tfal tudn hoin tryc tilp cho ao nuoi ca fra hay mot sd muc' dich sir dung khac vdi ylu cau chat lugng nudc phii hop HI thong nho gpn c6 khd nang di dpng (raobile system) de xir ly nudc thai cac ao nudi khic phuc vu muc dich tai sOr dung nudc thai TAX LIEU THAM KHAO APHA.AWWA,WEF (1998) Standard Methods for the Examination of Water and Wastewater, 20"' ed American Public Health Association, Washington DC Basu, O D and Huck, P M (2005) Impact of support media in an integrated biofiltersubmerged membrane system Water Research 39 (17), 4220-4228 Chae K.J., Yim, S.K., Choi K.H (2004) Application ofa sponge media (BioCube) process for upgrading and expansion of Tgp chi Kboa boc Tru&ng Dgi hgc Cdn Tho Pliin A Khoa hgc Tu nbien Cong nglie vd Mdi tnrang: 29 (2013): 45-S^W^^ existing caprolactam wastewater freatment plant for nitrogen removal Water Sci Technol 50 163-171 Cho, J., Song, K.G., Lee, S.H Anh K.H (2005) Sequencing anoxic/anaerobic membrane bioreactor (SAM) pilot plant for advanced wastewater treatment Desalination n8 (1-30, 219-225 Cdte, P., Buisson, H., Pound, C and Arakaki, G (1997) Iraraersed membrane activated sludge for the reuse of municipal wastewater Desalination, 113(2-3), 189-196 Guo W., Ngo, H.-H., Palmer, CO., Xing, W Hu A.Y.-J., Listowski, A (2009) Roles of sponge sizes andraerabraneXypes in a single stage sponge-submerged membrane bioreactor for improving nutrient removal from wastewater for reuse Desalination 249, 672-676 Guo W., Ngo H.-Hao Dharmawan, F., Palmer, C.G (2010) Roles of polyurethane foam in aerobic moving and fixed bed bioreactors Bioresource Technology 101, 1435-1439 Guo, W.S., Vigneswaran S Ngo, H.H., Kandasaray, J and Yoon, S (2008) The role of a membrane perforraance enhancer in a membrane bioreactor: a comparison with other submerged membrane hybrid systems Desalination231 305-313 Jamal Khan S Shazia I., Sadaf J., Visvanathan C, Jegatheesan V (2011) Performance of suspended and sponge MBR systems infreatinghigh strength synthetic wastewater Bioresource Technology 102 5331-5336 10 Kok-K\^ ang, Ng, Cheng-Fang L Sri, C.P., Pui-Kwan A.H and Ping-Yi, Y (2011) Reduced membrane foulmg in a novel bioentrapped nierabrane reactor for freatment of food and beverage processing wastewater Water research 45, 4269-4278 11 Leiknes T., Odegaard H (2001) The development ofa biofilm membrane bioreactor Desalination 202 135-143 12.Ngo, H.H Nguyen, M.C., Sangvikar, N.G., Hoang T.T.L., Guo, W.S (2006) Simple ' approaches towards a design of an attachedgrowth sponge bioreactor (AGSB) for wastewater freatment and reuse Water Sci Technol 54, 191-197 13 QCVN 08:2008/BTNMT Viemam national technical regulation for surface water quality 14 QCVN II:2008/BTNMT Viefriam national technical regulation on the effluent of aquatic products processing industry l5.Sombatsorapop, K Visvanathan, C and Aim, R Ben (2006) Evaluation of biofouling phenomenon in suspended and attached growth membrane bioreactor systems Desalination Volume 201, Issue 1-3,138-149 16 Thanh, B.X., Visvanathana C, Ben Aim, R (2009) Characterization of aerobic granular sludge at various organic loadingrates Process Biochemistry, 44(2), 242-245 17 Tien Nguyen, T., Ngo H.H„ Guo, W., Johnston, A., Listowski, A (2010) Effects of sponge size and type on the performance of an up-flow sponge bioreactor in primary treated sewage effluent freatment Bioresource Technology 101, 1416-1420 18 US.EPA (2004) Guidelines for Water Reuse, U.S Environmental Protection Agency, Municipal Support Division, Office of Wastewater Management, Washington, DC No 625/R-04/108 19 Visvanathan, C, Ben, A., and Parameshwaran, K (2000) Membrane separation bioreactor for wastewater treatment Critical Reviews in Environment Science and Technology 30 (\), 1-48 ... thii ao nuoi ca fra nhan tao Nudc thai nhdn tao dugc pha chi tir nudc cip, thiic dn viin cila ci tra va NH^Cl Nlng dl nhiira trung binh ciia nudc thdi ao nudi ca fra va nudc thai nhin tao (cd... thdi gian van hanh Kit qud ndy cfao thiy uu diem cua sponge frong bl MBR la MLSS tip frung frong sponge cang nhieu lam eho MLSS bim lo Iiing cdng it Iai vd sponge cp sdt vdi bl ragt mang tao dieu... luu nudc Gid thi sponge thim vao bl MBR giiip lim giam duoc bin ming nhd vao sy bim dinh ciia sinh khii len bi mat sponge, di vdo sponge yd viec chuyin dpng ty frong he thdng tao dilu kiln cp