Do Khac Uan vd cs Tap chi KHOA HOC & CONG NGHE 78(02) 87 92 NGHIEN ClTU ITNG DUNG KY T H U A T VI SONG CHO QUA T R I N H GIAI P H O N G P H O T P H O TlT BUN T H A I Do Kh2c U§n "• ''''̂, Mai Anh Khoa ''''''''[.]
Do Khac Uan vd cs Tap chi KHOA HOC & CONG NGHE 78(02): 87 - 92 NGHIEN ClTU ITNG D U N G KY T H U A T VI S O N G CHO QUA T R I N H G I A I P H O N G P H O T P H O TlT BUN T H A I Do Kh2c UĐn "ã^', Mai Anh Khoa ''*' Trirdng Dal hoc Bdch Khoa Ha \'ol ' Dal hoc CN Nanyang, Singapore Dal hoc That Nguyen TOM T A T Nghien cuu giai phong photpho (TP) tii' biin thai dong vai tro quan de thu hoi nguon photpho cho nganh cong nghiep phan bon Bai bao trinh bay ket qua nghien cu'u ap dung ky thuat vi song nham giai phong P tir biin thai Nghien cuu dugc tien hanh a eac dai nhiet 40, 60, 80 va 100°C va thai gian xu ly 5, 10, 15 va 20 phut Ket qua thu dugc cho thay dieu kien thich hgp de giai phong TP ttr bun thai bang phuong phap xir ly vi s6ng la 80°C va thai gian xii ly 10 phut dieu kien do, tren 80% TP biin co the dugc giai phong khoi biin Ngoai ra, phan nita (TN) cung dugc giai phong qua trinh xu ly Toe giai phong TTM cung tang rat nhanh khoang 10 phiit xir ly ban dau, sau da giam dan Su giai phong ciia cac chat hiru ca (tinh theo COD) cung tang len dang ke tang nhiet va thai gian xir ly nhiet cang cao, COD giai phong cang nhieu Dac biet, khoi lugng biin va kich thuac eac hat biin giam dang ke sau xir ly, phii hgp vai sir bien thien giai phong ciia TP, TN va COD Tir khoa: biin ihdl, glal phong photpho, gldm khoi lirong biin, vl song DAT VAN DE Tru' lupng quang photphat noi chung va nguon photpho (TP) noi rieng cang can kiet toe khai thac cang tang de dap irng nhu cau san xuat phan bon diing nong nghiep va cac nganh cong nghiep bot giat, chat tay rira, phu gia thuc an gia siic, va cac ung dung dac biet nhu che tao vat lieu chong chay [1-2] Do tinh trang khan hiem P, chi 14 thang (tii- thang 1/2007 den thang 3/2008) gia cua quang photphat da tang len lan, tti' 50 USD/tan len dSn 350 USD/t4n [3] Truoc sue ep ve su can kiet nguon P, huong nghien cuu thu hoi va tai sir dung cac nguon thai chira P (vi du nuoc thai sinh hoat, biin thai, phan-nuoc tieu nguoi, hoac phan gia cam) da dugc quan tam va chii phat tri^n [4,5,6,7] Biin thai tir qua trinh xu ly nuoc thai bang phuang phap sinh hoc co nong TP dao dong kha Ion, thuang tii- den 12% [8] Cho nen nghien ciiu da chii y den kha nang thu hoi TP tir biin thai De co the thu hoi dugc TP tiibiin thai, thi truac tien can phai giai phong Tel: 0968533.888; Email: khoamaiO'.gmail.com dugc phan TP biin thai (dang ran) sang TP hoa tan (dang photphat), sau moi tien hanh ket tiia a dang muoi photphat (vi du canxi photphat) Cac phuong phap giai phong TP til- biin thai bao gom phuong phap boa hoc, phuong phap hoa hoc ket hop gia nhiet, hoac phuong phap sinh hoc yem [9,10,11] Tuy nhien, cac phuong phap can phai bo sung boa chat de thuc day phan ung hoa tan, hoac can thai gian dai de hoan tat phan iing phan giai biin Trong nhung nam gan day, ky thuat vi song da dugc sii- dung cho nhieu muc dich khac nhau, vi du diing cho qua trinh tiet triing va khir triing cong nghiep thuc pham, dung dS pha mau phong thi nghiem, hoac dung de nau chin thirc an [12,13,14] Ky thuat vi song co nhieu uu diem so vai phuong phap gia nhiet thong thuong, la thai gian gia nhiet nhanh, tinh dong nhat ciia qua trinh truyen nhiet (cho ca ben va tai hh mat cua vat lieu can xir ly) va de dang kilm soat nhiet dp ciia qua trinh chinh xac [12] Do do, nghien ciru thu nghiem ap dung ky thuat vi song cho xir ly biin thai va danh gia kha nang giai phong TP tir biin thai rat can thiet va co y nghTa 87 Do Khac Uan vo cs 78(02): 87 - 92 Tap chi KHOA HOC & CONG NGHE Bai bao trinh bay ket qua nghien ciiu ap dung ky thuat vi song nham giai phong TP tir biin thai Ngoai ra, nghien cuu cung danh gia su giai phong nito-, cac hop chat huu ca va miJC dp giam ham lugng bun sau qua trinh xu ly biin bang ky thuat vi song PHUONG PHAP THUC HIEN Mo tathi nghiem Thi nghiem xu- ly bun thai nghien cuu dupe tien hanh gian doan theo tung me Cac mau biin can xu- ly (70 mL hon hpp bun CO ham lugng chat ran (TSS) la 10000 mg/L) duac dua vao cac binh dung mau Cac binh mau dugc dua vao 16 vi song (MARS, CEM Co., USA) CO tan so 2450 MHz va cong suat d4u cue dai la 1600 W (Hinh 1) M6i chu trinh hoat dong, he thong c6 the tien hanh thi nghiem dong thai voi 12 binh dung mau (the tich moi binh 100 mL), voi ap suat lam viec len den 30 atm He thong co bp phan kiem soat nhiet tu dong de dieu chinh nhiet dp cho qua trinh xii- ly Cac thi nghiem dugc tien hanh a cac dai nhiet dp 40, 60, 80 va 100°C bang viec thiet lap chuong trinh kiem soat va dieu chinh nhiet tu dong Cac thi nghiem dugc tien hanh cac khoang thai gian 5, 10, 15 va 20 phiit Sau moi loat thi nghiem, cac mau bun dupe lay va tien hanh phan tich cac thong so theo muc dich nghien ciiu Cac thi nghiem deu duac tien hanh lap lai nhieu lan nham dam bao so lieu thu dupe co dp tin cay cao Phuoflg phap lay mau va phan tich Cac mlu thu dugc sau moi thai gian va nhiet dp phan ung dugc tien hanh ly tam a 5000 vong/phiit phiit Phan nuoc thu dugc diing de phan tich cac thong so nhu cau oxi hoa hpc (COD), tong photpho (TP), tong nito (TN) Tat ca cac mau phan tich dugc tien hanh theo cac phuong phap chuan dupe trinh bay chi tik tai lieu APHA [15] Cu th6 nhu sau: Mau phan tich COD dugc dua vao ong phan tich COD va phan giai mau bang thiet bi phan ung COD (Model DRB200, Hach Corp., USA) a nhiet dp 150°C h M I U sau phan giai dupe lam nguoi den nhiet phong va b.nng thiet bj Hach (Model DR/2500, Hach Corp., USA) a buoc song 620 nm Mau phan tich TP dupe dua vao ong phan tich TP va phan giai mau a nhiet 150°C 30 h Sau bang thiet bj Hach a buoc song 430 nm Mau phan tich TN dupe phan giai mau a nhiet dp 105°C 30 h Mau sau phan giai dupe bang thiet bj Hach a buoc song 410 nm Ham lugng tong chat ran (TSS) dupe xac djnh bang each dua mau biin vao dTa nhom chuyen dung va say kho 16 say (Memmert UFP600, GmbH, Germany) a 105°C h Ngoai ra, su phan bo kich thuoc hat biin truac va sau xu- ly dugc xac djnh bang phuong phap nhieu xa tia lade (su dung thiet bi Mastersizer, Malvern Instruments Ltd., UK) Ngu6n vi song Gircrng phan xa Khi Hinh Hinh anh va so d6 nguyen ly cua 16 vi song diing nghien cim 88 Do Khac Uan vd cs Tap chi KHOA HOC & CONG NGHE 78(02): 87 - 92 KET QUA VA THAO LUAN Sir giai phong nita tir bim thai Sir giai phong photpho tir biin thai Su thay doi ve nong dp TN giai phong tir bim qua trinh xu ly vi song dupe bieu dien tren hinh Hinh bieu dien su bien thien nong dp TP giai phong khoi bun qua trinh xu ly biin bang ky thuat vi song tai cac khoang nhiet dp (40 - 100°C) va thai gian xu ly khac (5-20 phiit) Tir ket qua thu dugc cho thay a 40°C toe dp giai phong TP tuong doi thap Sau 20 phut xii ly, nong TP giai phong thu dugc lon nhat chi la 50 mg/L Tuy nhien, nhiet dp xur ly tang len 60, 80 va 100°C, toe dp giai phong TP tang len rat nhanh khoang 10 phiit dau tien, vai nong dp TP giai phong thu dugc tuong irng lan lugt la 98,3; 145,5; 168,4 mg/L, chiem den 80-83% nong TP cue dai giai phong dugc sau 20 phiit Tuy nhien, tiep tuc tang thoi gian xu ly, toe giai phong TP co xu the giam Tir cac ket qua thu dugc cho thay dieu kien thich hgp cho qua trinh giai phong TP tir biin thai bang phuang phap xu ly vi song la 80°C, voi thai gian xir ly la 10 phiit TP giai phong dugc co the thu hoi bang each tao ket tua vai cac muoi canxi de tao canxi photphat (Ca3(P04)2) Ca3(P04J2 la hgp chat tuong tu nhu quang photphat khai thac tir mo, va CO the su dung lam nguyen lieu cho nganh cong nghiep phan bon Ngoai ra, TP CO the dugc thu hoi bang each tao ket tua magie amoni photphat hydrat (con gpi la tinh the struvite) theo phuong trinh phan iing [8]: NH4' + Mg^' + PO4'" + 6H2O ^ MgNH4P04.6H20 Struvite co dac diem phan giai cham va co the sir dung true tiep de lam phan bon cho ••-•»•*••*•- TP TP TP TP giai giai giai giai phong phong phong phong tai lai lai lai 40°C 60°C 80''C lOO'C Thoi gian xu ly (phut) Hinh Sir giai phong TP tii- biin thai tai cac khoang nhiet dp va thai gian khac Thoi gian xu ly (phut) Hinh Sir giai phong TN tir bun thai tai cac khoang nhiet dp va thai gian khac Tir hinh ve cho thay, tuong tu nhu sir bien thien ciia TP, TN ciing dugc giai ph6ng nhanh qua trinh xu ly 40°C toe giai phong TN khong dang ke Nong TN giai phong thu dugc sau 20 phiit xu ly khoang 82,4 mg/L Tuy nhien, nhiet xu- ly tang len 60, 80 va 100°C, t6c giai phong TN tang nhanh Sau 20 phut, nong TN giai phong dugc tuong iing la 220,6 , 312,5 va 372,2 mg/L Mot dieu thu vj la, toe giai phong TN cung tang rat nhanh khoang 10 phut xii ly ban dau, sau da giam dan Trong 10 phiit, nong TN giai phong dugc chilm den 75-82% so voi nong TN giai phong dugc sau 20 phut xir ly Can luu y rang, qua trinh xir ly nhiet TN giai phong dugc chu yeu a dang nito hiru ca [16] Cho nen, nghien cuu da khuyen cao rang neu biin sau xir ly nhiet dugc tuan hoan tra lai he thong xur ly nuac thai se lam tang tai lugng nita dau vao va co the dan den vugt qua kha nang xu ly nita cua he thong Do vay, can phai phai tinh den van de ban che sir giai phong ciia nito xur ly biin bang phuang phap nhiet Hay noi each khac, can ban che qua trinh xii ly biin a dai nhiet cao Sir giai phong cac chat hiru ca tir biin thai Khi dugc gia nhiet a nhiet cao tren 60°C, biin CO kha nang bi pha hiiy va giai phong cac hgp chat hiru ca hoa tan [8] Thong thuang 89 78(02): 87 - 92 Tap chi KHOA HOC & CONG NGHE Do Khac Uan vd cs phan cac chat hOu ca giai phong qua trinh xu ly biin rat phuc tap, bao gom nhieu hgp chat huu ca khac [9] Trong nghien ciiu su giai phong ciia cac chat hiru CO' dugc danh gia thong qua phan tich nong dp COD ciia dung djch thu dugc sau qua trinh xu- ly Hinh bieu dien sir bien thien ve nong dp COD giai ph6ng a cac khoang nhiet dp va thai gian xu ly khac Ket qua thu dupe cho thay COD tang len dang ke tang nhiet dp va thai gian xu ly nhiet dp cang cao, COD giai phong cang nhieu Ket qua thu dupe tii' nghien ciiu cho thay mpt uu diem nira cua viec xu ly bun bang phuang phap vi song la co kha nang tao mpt lupng dang ke cac chat hQu coh6a tan Day la nguon cacbon huu ca co gia trj neu dugc bo sung cho qua trinh khii nitrat he thong xii- ly nuac thai D I kiSm chiing sir pha va hat bim a cac dieu kien xu ly khac nhau, chiing toi tien hanh sir phan bo kich thuoc ciia cac hat biin truac va sau xir ly vi song Ket qua thu dugc (tinh theo phan tram the tich hat bim mau kiem tra) dugc bieu dien tren hinh Tir hinh chiing ta de dang thay rang, kich thuac cac hat biin giam dang ke sau xiir ly vi song Truac xu ly, khoang 12% so hat biin CO kich thuac khoang 550 |a,m Sau xir ly a 40, 60, 80 va lOOT, kich thuac cua hat biin giam xuong lan lugt la 465, 342, 158, va 122 |j.m Hinh bieu dien hinh anh biin truoc va sau xu ly vi song bang kinh hien vi dien tu (su dung may Olympus SZX9, Olympus Co Ltd., Japan) Ket qua quan sat cho thay sau qua trinh x\x ly hau het bong biin da bj pha va Nha qua trinh nay, cac chat dinh duang va cac chat hiiu co- da dugc giai phong khoi bun va di vao dung djch 5000 4500 4000 COD giai ptiong tai 40°C t ^ i ^ COO giai ptiong tai 60°C ^:=^ COD giai phong tai 80°C o™a COD giai ptiong tai 100'C ^ 3500 ^1 E 3000 D 2500 o ^2000 c o Z 1500 200 300 400 500 600 Kich thuoc hat bun (nm) ThOi gian xu ly (phut) Hinh Muc giam khoi lirgng bun thai sau qua trinh xu ly bang vi song Hinh Su giai phong COD tir biin thai tai cac khoang nhiet dp va thai gian khac Muc dp giam khoi lugng bun thai sau qua trinh xii ly bun bang vi song Sir suy giam ve TSS thu dugc qua trinh xir ly bang ky thuat vi song dugc the hien tren hinh Tu- hinh ve cho thay, a 40°C, toe dp suy giam TSS rk cham Khi nhiet dp dat 60°C, toe dp giam TSS tang nhanh chong, va khoi lupng bun giam cang nhieu a nhiet dp cang cao Nhu vay, k8t qua thu dupe phii hpp vai su bien thien giai phong ciia TP, TN va COD 90 10500 10000 ã ô - TSS TSS TSS TSS sau sau sau sau u 1/ tai "lO'C —'*— %TSS giam duoc o 40°C " %TSS giam duoc o 60°C u 1/ tai SO'C u \i tai eO^C %TSS 9>am duoc o SCC xulylBilOO^C - * - %TSSqiamduoco100''C 9500 ^ 90O0 § 8500 Thoi gian xu ly (phut) Hinh Phan bo kich thuac hat biin sau qua trinh xu ly bang vi song Do Khac Uan vd cs Tap chi KHOA HOC & CONG NGHE 78(02): 87 - 92 •.31 f fX- s^" ^ ffc ^ãô # ^ ã ã'.^' "hi Hinh Hinh anh biin truac va sau xii- ly vi song (mau xir ly a 80°C, 10 phut, phong dai 100 lan) KET LUAN Cac ket qua thu dugc tii- nghien ciiu cho thay rang ky thuat vi song co the su- dung de giai phong TP tir biin thai Dieu kien thich hgp cho qua trinh giai ph6ng TP tCi- biin thai bang phuang phap xu- ly vi song la 80°C, voi thai gian XU' ly la 10 phiit dieu kien do, tren 80% lugng TP co the dugc giai phong khoi biin thai Ben canh su giai phong TP, TN cung dugc giai phong nhanh qua trinh xur ly Ci cac dieu kien thi nghiem, toe giai phong TN Cling tang rat nhanh khoang 10 phiit xu ly ban dau (chiem den 75-82% so voi nong TN giai phong cue dai), sau da giam dan Sir giai phong ciia cac chat huu ca qua trinh xii' ly vi song dugc danh gia thong qua nong COD COD giai phong tang len dang ke tang nhiet va thai gian xir ly nhiet cang cao, COD giai phong cang nhi^u Dac biet, khoi lugng biin va kich thuoc cac hat biin giam dang ke sau xir ly vi song K6t qua thu dupe phu hgp voi su bien thien giai phong ciia TP TN va COD Nhan xet chung, phuong phap vi song CO tinh uu di^m lon la thai gian xu- ly nhanh va khong can b6 sung bat cu- hoa chat nao TP giai phong hoan toan co kha nang thu hoi dugc bang cac qua trinh ket tiia tiep theo Tuy nhien, c4n phai luu y rSng qua trinh vi song chiu anh huong ciia nhieu yeu to khac nhu he s6 t6n thk dien nang, ton that nhiet dg, Cho nen can phai nghien ciiu them ve cac yeu to de nang cao hieu qua qua trinh giai phong TP tir bun thai TAI LIEU THAM KHAO [l].IFA (2007), International fertilizer supply and demand, in Australian Fertilizer Industry Conference 2007, International Fertilizer Industry Association, August 2007 [2].EFMA (2000), Phosphorus; Essential element for food Production, European Fertilizer Manufacturers Association [3].Do Khac uan Dang Kim Chi (2008) Tinh trang khan hiim photpho va su can thiet cua viec tai sir dung ngudn thai chira photpho, Tgp chi Khoa hoc vd Phdt trien, 6: 510-511 [4].Steen, I (1998) Phosphorus availability in the 21st Century: Mananagement of a non-renewable resource Phosphorus and Potassium, 217: 25-31 [5].WHO (2006) Guidelines for the safe use of wastewater, excreta and greywaler Volume 4; Excreta and greywaler use In agriculture World Health Organisation [6] Banu, R., D.-K Uan, and l.-T Yeom (2008), Enhanced phosphorous recovery from EBPR sludge In the presence of condensed phosphate The 1st IWA Asia-Pacific young water professional conference, GIST Gwangju, Korea 8-10 Dec 2008 [7].D6 Khac uan, Mai Anh Khoa (2010) Danh gia kha nang thu h6i photpho tir phan ga cong nghiep bang mot s6 phuong phap ly, hoa va sinh hpc, Tgp chi Khoa hoc vd Cong nghe Dgi hoc Thai Nguyen (Tap70, s6 08, trang 127-132) [8] Tchobanoglous, G., Burton, F.L and Stensel, H.D (2003) Wastewater engineering; Treatment, disposal and reuse 4th edn McGraw-Hill, New York Do Khac Uan vd cs Tap chi KHOA HOC & CONG NGHE [9].Borowski, S and J.S Szopa (2007) Experiences with the dual digestion of municipal sewage sludge Blares Tech., 98: 1199-1207 [10] Campos, J.L., L Otero, A Franco, A Mosquera-Corral, and E Roca (2009) Ozonation strategies to reduce sludge production of a seafood industry WWTP, 5/orei Tech., 100: 1069-1073 [11] Kim, T.-H., S.-R Lee, Y.-K Nam, J Yang, C Park, and M Lee (2009) Disintegration of excess activated sludge by hydrogen peroxide oxidation Desalination, 246: 275-284 [12] Zhang, H., A.K Datta, l.A Taub, and C Doona (2001) Electromagnetics, heat transfer, and thermokinetics in microwave sterilization, AIChE Journal, 41: 1957-1968 [13] Ntichter, M., B Ondruschka, D Wei, R Beckert, W Bonrath, and A Gum (2005) 78(02): 87 - 92 Contribution to the qualification of technical microwave systems and to the validation of microwave-assisted reactions and processes, Chem Eng Tech, 28: 871-881 [14] Bierbaum, R., M Ntichter, and B Ondruschka (2005) Microwave-assisted reaction engineering: Microwave apparatus at mini-plant Scale with online analysis, Chem Eng Tech., 28: 427-431 [15] APHA (2005) Standard methods for the examination of water and wastewater 21st edition, American Water Works Association, Water Pollution and Control Federation, Washington, DC USA [16] Shanableh, A (2000) Production of useful organic matter fi-om sludge using hydrothermal treatment Water Res., 34: 945-951 ABSTRACT A STUDY ON APPLICATION OF MICROWAVE ENGINEERING FOR PHOSPHORUS RELEASE FROM WASTED SLUDGE Do Khac Uan "'^', Mai Anh Khoa '^ *' ' Hanoi University of Science and Technology ' Nanyang Technological University Singapore •' Thai Nguyen University Releasing phosphorus (TP) from wasted sludge plays an important role in phosphorus recovery for the fertilizer industry This paper presents a study on TP released from wasted sludge using microwave engineering The experiments were carried out at various temperatures (40, 60, 80, and 100°C) and treatment times (5, 10, 15, and 20 min) The obtained results showed that the proper conditions for TP release were 80°C and 10 At that condition, over 80% of TP was released from sludge In addition, total nitrogen (TN) was also released during the microwave sludge treatment The TN release rate was also increased rapidly within the first 10 min, and reduced gradually after that The release of organic carbon (as Chemical Oxygen Demand, COD) was increased significantly when the treatment temperature and time were increased The higher temperature resulted in more COD released Especially, sludge mass and its size were also reduced significantly after the microwave treatment The observations were agreed with the TP, TN and COD releasing profiles Key words: microwave, phosphous release, sludge reduction, wasted sludge Tel: 0968533.888; Email; khoamaifd^gmail.com 92 ... tii- nghien ciiu cho thay rang ky thuat vi song co the su- dung de giai phong TP tir biin thai Dieu kien thich hgp cho qua trinh giai ph6ng TP tCi- biin thai bang phuang phap xu- ly vi song la 80°C,... phong TP co xu the giam Tir cac ket qua thu dugc cho thay dieu kien thich hgp cho qua trinh giai phong TP tir biin thai bang phuang phap xu ly vi song la 80°C, voi thai gian xir ly la 10 phiit... thu dupe cho thay COD tang len dang ke tang nhiet dp va thai gian xu ly nhiet dp cang cao, COD giai phong cang nhieu Ket qua thu dupe tii'' nghien ciiu cho thay mpt uu diem nira cua viec xu ly