71 nghien cuu xu li nuoc thai cho tren mo hinh

j^msasMBM 23 NGHIEN CUU XU'LY NUlSC THAI CHOfTREN MO HINH HdP KHOI BASTAF - BAI LOG NGAM TRONG CAY • l.&m\lnhSfSn - Dai hoc Ky Thu4t CSng Nghe Tp Ho Chi Minh, ViStNam LSm Hoang Vu - Dai hoc Khoa hoc Tu nhien Tp HS Chi Minh, ViitNam T6M TAT Ntfdc thai chd tff Idu dtfdc bidt den la tdc nhan gay nhidm Idn ddi vdi ngu6n ntfdc Tuy nhien, hien tai ntfdc thai d cdc chd deu thai trtfc tiep sdng, sudi hodc he thdng cdng ntfdc thai sinh hoat chung cua khu vtfc ddn ctf xung quanh Sd dT hau hdt cdc chd khdng xl^ ly ntfdc thai la quy md chd nhd khdngdiikinhphidddluttfxdy dtfng he thdng xffly dat yeu cau Vdi nhffng van dd xuaft phdt tijf thtfc tiln d'y, mot he thdng vdi chi phi xdy dtfng thap nhiTng hi$u qua cao va dn dinh dtfdc nghiSn ciJu la md hmh hdp khdi BASTAF - bai loc nglm Theo nghidn ctfu, md hinh hdp khdi BASTAF - bai Ipc nglm dtfdc vdn hanh theo nguyen tac ddng ntfdc ttf chay Trong do, be BASTAF la be ky vdi ngdn: ngan chtfa, ngan phan buy sinh hpc ky vd ngdn Ipc ky Bai Ipc ngam trdng cay Trau bd trang (Syngonium Podophyllum) cd dien tich be mat Id 0,24 m^ Ntfdc thai lay ttf chd Dau mdi Nong san Tbii Dtfc Chay mo hinh de khdo sdt thdi gian Itfu tditfudtfa tren hieu sua't x^ ly vd nghi6n ctfu kha nang xii" ly ciia ttfng phan md hinh hdp khdi Kd^t qua cho thay thdi gian lull tditfucua md hinh hdp khd'i la 48 gid Vdi thdi gian Itfu 48 gid thi hi$u sud'txuT ly la 89,8% COD; 93,7% TSS; 84,4% TP; 81,4% TN va 94,5% CoUform Ntfdc thdi dIu dat quy chuan loai A cua QCVN 24:2009/BTISIMT d hau hdt cac thdng sd Mot kdt qua nghien ctfu khac cho thlfy hdi Ipc ngam cd hieu suat xii ly cao hdn be BASTAF d tdt ca cdc thdng sd, ddc biet Id Nitd tdng, Phospho tdng va Coliform ABSTRACT Market's wastewater is a significant source of water pollution However, nowadays much market's wastewater is released in rivers, streams or domestic wastewater system in residence area directly Small-scale markets can not afford to invest in a standard treatment system for causing wastewater to go untreated In order to solve practical problems, the treatment system with low expenses but bringing efficient and stable's result was study: Entire System BASTAF - Constructed Wetland According to research, Entire System BASTAF - Constructed Wetland was operated by the the principle of gravity flow BASTAF was an anaerobic lank including parts: one sedimentation part, two anaerobic decomposition's parts and two anaerobicfilter'sparts The Constructed Wetland planted Syngonium Podophyllum with the surface area of dieriverwas 0,24 square metres The raw wastewater was taken from the Thu Due Agriculture Wholesale Market Operating entire system to survey optimum retention time based on treated productivity and researching the capability of treatment of each component in of entire system As a result, the optimum retention time of the entire system was 48 hours, retention tune was 48 hours with treated productivity: 89,8% of COD; 93,7% of TSS; 84,4% of TP; 81,4% of TN and 9,5% of Coliform The wastewater after treatment achieved A standard of • 24 «M1!lllillililJ:IJilllliyiU • QCVN 24:2009/BTNMT, almost environmental parametes Another study shows that BASTAF has productivity higher than Constructed Wetland on all parameters, especially in Total Nitrogen, Total Phosphorus and Colifrom LMyCTlfeU NGHIEN Ctru Nghien cffu phan vd tinh chd't cua ntfdc thdi chd da ngdnh hdng tu: dd xac dinh dtfdc phtfdng phdp xiif ly ntfdc thdi thfch hdp Nghien cffu, ddnh gid khd ndng xiJ Iy ciia md hinh hdp khdi BASTAF - Bai Lpc Ngam ddi vdintfdcthdichd De xua't cdng nghe xu* ly ntfdc thdi chd vdi chi phi thd'p vd than thien vdi moi trtfdng NQI DUNG NGHIEN ClTU De dat dtfdc nhffng muc tieu de ra, nhdm nghien cffu chung tdi dd thtfc hien cdc ndi dung sau: - Phan tich thdnh phIn vd tinh cha't cua ntfdc thdi chd Cu the, nhdm nghien ctfu lay mlu ntfdc thdi tai Chd Dau mdi Ndng Sdn Thu Dffc Tp Ho Chi Minh - Thidt kd mo hinh hdp khdi phuc vu nghidn cffu: mo hinh gdm bd phan chinh la be chtfa ntfdc thai, be BASTAF va bai lpc nglm trdng cay Trau Ba Trang (Syngonium Podophyllum) - Phdn tich, danh gia kha ndng xu* ly ntfdc thai cua mo hinh hdp khdi BASTAF - Bai Lpc Nglm tren cd sd thdi gian Itfu ntfdc - Khdo sdt hieu qud xu' ly ttfng phIn cua be BASTAF vd bai lpc nglm Ttf nhffng kdt qua cd dtfdc, kdt luan ve tinh khd thi cua mo hinh ddng thdi de xusTt cdng nghe xff ly ntfdc thdi chd tren thtfc te' P H U O N G P H A P NGHIEN COU 3.1 Phffdng phap luSn: Ntfdc thai chd chtfa nhieu phIn nhilm nhtftig dac trtfng chu yeu la d nhiem hffu cd, hamltfdng giau Nitd, Photpho, vi sinh vat Cac phan ndu khdng dtfdc xff ly trietde se anh htfdng den sffc kbde cua ngtfdi, he dong thtfc vat xung quanh Nam dtfdc cac dac didm do, mo hinh hdp kho'i BASTSAF - Bdi Lpc Ngam trdng cay dtfdc de xua't de xff ly triet de cac thdnh phIn nhidm ntfdc thdi chd Ben canh dd, md hinh hdp kho'i cdn dtfdc danh gia tinh kha thi rdt cao dp dung vao thtfc tevi chi phi thap, thdn thien moi trtfdng vd tao nhieu san pham phu hffu Ich 3.2 Phffdng phap cu thd: Nghien cffu tdng hdp t^t ca lai lieu lien quan ddn de tai nhtf cdc tap chi khoa hoc, cdc c6ng trinh nghien cffu cd nhffng ket qua hffu ich cho de tai Phtfdng phap xdy dtfng mo binh: tren cd sd tinb todn thiiy Itfc, Itfu Itfdng ntfdc thdi thich hdp de xay dtfng cac ihdng sd cd ban cho md hinh Phtfdng phdp chpn thtfc vat cho bai lpc nglm: thtfc vdt bai lpc ngam phai la loai c6 vdng ddi sinh trtfdng ngan, than cd, rd dai bdm sau dffdi cdc Idp dd't vd ddc biet cd kha ndng lam sach ntfdc Phtfdng phap phan thu thap va phdn tich mdu: mdu dffdc ld'y tai chd Dau Mdi Thu DffcTpHo Chi Minh sau dd dtfdc chay md hinh va phan tich cdc thdng sd nhidm tai phong thi nghiem Khoa Mdi trtfdng - Dai hpc Khoa hpc ttf nhi6n Tp H Chi Minh Phtfdng phap xu' ly sdlieu: cdc sd lieu thu thap, phdn tich, tdng hdp tff kdt qud thi nghiem • lamiiiMiiMtH'ii'ii 25 • dtfdc xu*ly bang phIn mdm Microsoft Excel 2007 vd Statgraphics Centurion XVI QUY TRINH THI NGHIEM: 4.1 Thidt kdmo hinh htfp khdi: 4.L1 Md hinh be BASTAF: M6 hinh dtfdc lam bang vdt li$u thuy tinb day 5mm vdi the tich thtfc bd la 0,2 m' ~ 200 lit KIcb thtfdc be nhtf sau: Dai X Rpng x Cao = m x 0,4m x 0,5m Be BASTAF cd ngan chinh Kich thtfdc mdi ngdn dtfdc trinh bdy bang Bdngl: Kich thudc cdc ngdn be BASTAF Kich thir6*c (m) Ten ngan Dai X Rpng x Cao Ngan chija 0,4 x 0,4 x 0.5 Ngan ky bac I 0,15x0,4x0,5 Ngan ky bac II 0,15x0,4x0,5 Ngan lpc ky I 0,15x0,4x0,5 Ngan lpc ky II 0,15x0,4x0,5 Bd BASTAF dtfdc ddy kin bang mot t^m xdp, phia tr8n mdi ngdn ddu cd dng nhtfa uPVC 019 dd tao qud trinh phdn buy sinh hpc cac hdp chd't hffu cdnhffCH4,H2S,C02 thoatra ngoai Giffa cac ngan be BASTAF dffdc ndi vdi bang Te nhtfa uPVC 021 Cac TB ndy dtfdc lap vao be BASTAF theo kieu dich ddc giup cho qua trinh xao trdn ntfdc thdi va biin ky xay tdt hdn 4.2.2 Mo hinh Bdi Loc Ngdm: Md hinh bai lpc ngam dd tai dtfdc thidt kdld mdt thiing nhtfa PE hinh hop chff nhdt vdi cac thdng so: - Thd tich vung lpc: 0,108 m' - Di$n tich bai lpc: 0,24 m^ - Kjch thtfdc bai lpc: Dai x Rpng x Cao = 60cm x 40cm x65cm H6 thdng phdn phd'i ntfdc vd thu ntfdc bai lpc nglmdtfdctbidtkd tff cdc dng nhtfa PVC 021 cd due Id Cau true cac Idp vdt li$u lpc bai lpc nglm theo chieu tff dtfdi 16n Id: sdi Idn, cat da't trdng Thdng sdcua mdi Idp vat Ueu dtfdc trinh bay bang sau: Hlnti Mo hinh Be' BASTAF mj7 Hinh 2: Mo hinh Bai Loc NgSm ««l!l!lill!l,IJJJilMMIU 26 Bdng 2: Vdt lieu loc hai loc ngitn ,, ^ The tich vilng loc ' tirong ling (m') Loai vat li^u Kich thirAc hat (mm) Kich thir^c viing I9C (cm) Soi Ion 8-10 x x 15 0,036 Cat 2-3 x x 15 0,036 Dat 1-3 x x 15 0,036 * Trong bai loc ng£m cay Trau bjl trSng Syngonium Podophyllum va AiXtSc phan bS dIu tren dien tich bai loc vdi trung binh: cay/ 0,03 tn 4.1.3 Lap dat mo hmh hap kho'i: Mo Mnh hc)p khd'i difdc iSp theo nguyen t^c ddng ni/dc thdi tit chay Do cao cua c5c bd phan mo Mnh dam bao cho ddng nUdc thai tuf chay theo cMeu: thiing nitdc thdi —> be BASTAF —> bai loc ngSm jmw^ Hinh 3- Mo hinti 3D hi)p kliSt Hinh 4: m Wn/i h0p khSi trln thuc t( 4.2Ba'trithinghi$m 4.2.1 Khdid^ng md hinh: • Thich nghi be BASTAF Bun ky kh! diTdc lay tCr co'ng thoat nirdc ve sinh tai Tram xuT ly nirdc thai chd Diu moiNdng sSn Thu Difc Sau do, bun ky dirdc cho vao ngSn ky cua be BASTAF The tich biin chiem khoang 1/3 th^ tich ngan ky Duy tri ham lUdng MLSS (Mixed Lipuoz Suspended Sohd - Cha't ran Id Iffng hdn hdp biin Idng) thich hdp cho qud trinh ph3n huy ky Dau hi6u bDn ky thich nghi vdi nUdc thdi chd: biin cd mau den xdm, hi mat niTdc cd nhi6u bpt khi, van tdc bun lang nhanh, kich thudc hat bun Idn, khdng cd biin ndi tren mat nifdc Nirdc thai sau lay tii chd ve se cho vao thung chlJa va bat dIu md van chay vao be BASTAF da chu'a biin ky vdng 10 Sau tijfng ngdy se ham llfdng COD tai be BASTAF de xem xet kha nang thich nghi cda md hinh vdi nifdc thdi chd - Trong va thich nghi c3y Tr^u Ba Tr^ng Cay Trau ba trang tren bai loc ngam difdc thich nghi dan vdi mfdc thdi chd Tlfdicay hang vdi nirdc thai chd cd nong dp tang dan tif 25% den 100% Sau mot thdi gian (khodng^ > EIBIlBiIliS 27 > 10-15 ngay) neu th^y cay sinh tnfdng va phat trien Id't thi cd th^ hdt dau chay md hinh 4.2.2 Chay mo hinh: - Xac dinh thcfi gian liAl td'i vfu B e khdo sdtthdi gian lifu HRT (Hydraulic Retention Time) nao Id td'i Uu cho qua trinh hoat ddng c i a hS thd'ng md hinh BASTAF - Bai Loc Ngam ta sd'dung cdng thifc sau de nghien cifu: HRT = _V Q" Trong do: HRT: thdi gian Itfu ntfdc (gid) V: the tich bd phdn tfng (m^) Q: Iffu Itfdng ddng vao (m%) Thdi gian Itfu HRT dtfdc dtfa vdo nghien cffu ddi vdi md hinh BASTAF - Bai Lpc Ngam la T, = 36 gid, T, = 48 gid, Tj = 60 gid Ttfdng tfng vdi nhffng thdi gian Itfu dd thi ta cd Itfu Itfdng ddng vdo la Q, = 3,1 lil/h; Q2= 2,5 lit/h; Q3= 4,2 lit/h (thd tich chtfa ntfdc cua bd BASTAF Id 150 lit) Ddi vdi mdi thdi gian Itfu khac nhau, ta se phan tich cac thdng sd'dd tff dd tinh hieu suat xff ly nham tim thdi gian Itfu td'i uff cho cd mo hinh K E T QUA N G H I E N ClTU: 5.1 Kdt qua p h a n tich m a u nffdc thai chd: Bdng 3: Ket qud phdn tich mdu nude ddu vdo Gia tri Chi tiSu pH 7,37 TSS (mg/I) 181,7 COD (mg/1) 481,2 BOD5(mg/l) 284,0 TN (mg/1) 73,2 TP (mg/1) 18,6 Coliform 48x10' (MPN/100ml) Cac chi tieu mdi trtfdng trung binh cua ntfdc thai chd khd cao, hau hdt ddu vtfdt tieu chud'n cho phep loai B cua QCVN 24;2009/BTNMT nhieu lan Trong dd, TSS g^p 3,6 Idn; T N g ^ p 5,2 l l n ; T P ga'p 10,9 Idn; BOD^ gap 9,5 l l n va COD gd'p 9,6 l^n Ham Itfdng chat hffu cd ntfdc thdi cao vdi l>cl ty 16 BOD3/COD la 0,59 thich hdp cho xff ly bang phtfdng phdp sinh hpc ky Ngodi ra, ham Itfdng cha't ran Id Iffng TSS, Nitd vd Phospho Idn cung la Hinh 5: Qud trinh khdi dong mo hinh qua COD • M'mimtimmmmiim 28 • dieu kien de chpn bai lpc ngam trdng cdy xff 1^ ntfdc thdi chd 5.2 Ket qua thich nghi md hinh hcfp khd'i vdi nu'dc thai ch^: 5.2.1 Keiqud thich nghi cua be BASTAF Dtfa vdo bidu dd hinh ta dd ddng nhan tbd'y COD dau be BASTAF giam din tCfng ngdy, ttfdngffngId hieu sud't xff I^ COD tdng theo Hieu sud't tdng lien tuc tff thff ddn ngdy thff Hi6u sud't bat dau dn dinh khodng 70% tff ngdy thff ddn thff 10 Qud trinh khdi ddng ket thiic vd cd thd bdt dau chay mo hinh Nguyen nhdn gilip qud trinh khdi ddng be BASTAF nit ng^n thdi gian Id vi sinfe vat bun ky dffdc lay tai chd nen da thich nghi vdi moi trffdng ntfdc thdi chd, khdng bi sdc vi ndng dd hodc tinh chd't ntfdc thai Chinh vi vdy, vi sinh vat tiep tuc hoat ddng phdn huy chd't hffu cd lam ham Iffdng COD dau giam nhanh qua cdc ngdy 5.2.2 Ket qud thich nghi cua cdy Trau bd trang Bai Lpc Ngam: Qua lOngaytffdi bang ntfdc thdi chd, cay Trau bd trSng sinh trtfdng vd phdt trien ra"! tdt, khong cd cay chdt, khdng cd sdu bo Sau mdt thdi gian, cd nhieu sinh vat di ctf ddn bai lpc ngam sinh sdng nhtf giun, mdi, cudn chieu giiip cho he dong thtfc vdt tai day them phong phii gdp phan tao canh quan da dang sinh vdt cho bai lpc nglm 5.3 Kdt qua chay md hinh hgfp khd'i vdi thcfi gian lirti (HRT) thay ddi 5.3.1 Hieu suat xHly tinh theo ham lUOng COD -*^ Ibttin Hinh 6: Ndng dp COD ddu vdt thdi gian luu khdc Hinh 7: Hieu suat xA ly COD theo gian litu Hinh cho thay, vdi thdi gian luxi HRT = 36h thi n6ng COD diu cdn Idn, khdng in dinh, dao ddng tit 123 -190 mg/L Cdn do'i vdi HRT = 48h thi nong dd COD dIu thap, khd on dinh, xap xi quy chuan loai A cua QCVN 24:2009/BTNMT Khi tSng thdi gian lifu len vdi HRT = 60h thi nong COD cung khdng giam la bao nhieu so vdi HRT = 48h Trung binh ndng dp COD dau cua cd HRT = 48h va HRT = 60h khoang 49,5 mg/L Tif hinh 7, tha'y dUdc hieu sua't xiJ ly vdi HRT = 36h chi khoang 70% NgUdc lai, vdi HRT = 48h vd HRT = 60h thi hieu sua't cao xap xi 90%, cd me hieu sua't len dg^n 95% Sd di vdi HRT = 36h thi Meu sua't xuf ly COD thd'p la thdi gian luu chUa du de cdc qud trinh \\S \^ sinh y jMosimmMEaL 29 • hda, hda ly loai bo cdc cbd^t hffu cdo nhiem dien md hinh hdp khdi BASTAF-bai lpc ngam 5.3.2 Hi^usuatxitly tinh theo ham lUcfng TSS Hinh 8: Ham Iuong TSS ddu vdi thdi gian luu khdc Hinh 9: Hieu su^txA ly TSS theo thdi gian lUu Ham Itfdng TSS ddu cua m6 hinh bdp khd'i BASTAF - bai lpc ngam thd'p va on dinh ddi vdi ca thdi gian Itfu khac Id 36 gid, 48 gid vd 60 gid Nhin vao hinh ta tha'y tlft ca kdt qua thu dtfdc deu dat loai A cua QCVN24:2009/BTNMT TSS dIu cao nha't la 34,7 mg/L, tha^pnhatla 5,5 mg/L Hieu sufTt xff ly TSS vdi thdi gian Itftf khac ddu cao xa'p xi 91 % Vdi hieu su^t trung binh cua HRT = 36h la 89,3%; HRT = 48h la 93,7%; HRT = 60h la 91,1% Nhtf vay kha nang xff ly TSS cua md hinh hdp khd'i BASTAF - Bai Lpc Ngdm ddi vdi ntfdc thai chd khdng phu thudc nbidu vdo thdi gian Itfu ntfdc 5.3.3 Hieu suatxiCly tinh theo ham lUdng TP K-'^?^z:^z^ Ilir»Bi -••SHi -*-.Bii -o-ftfe —U'ii.\-cii.'\i;:i;>"-Bnc;.[ri Hinh 10: Ham luang TP ddu vdi thdi gian lUu khdc Hinh 11: Hieu sud't xi^ ly TP theo thdi gian luu Hinh 10 cho tha'y dtfdc ham Itfdng TP ddu giffa cdc me cua HRT = 36h cd sff dao dong kha Idn tff 5,1 -10,2mg/L, trung binh khoang mg/L Hdm Iffdng TP ndy deu vtfdt so vdi loai A ( [7] Brix, H., (1997), Do macrophytes play a role in constructed treatment wetland? SCi Tech, page 11-17 [8] Mitsch, W.J and Gosselink, J.G (1993), Wetlands Van Nostrand Reinhold, Nev/ York [9] Hammer, D.A, (1992), Creating freshwater wetlands Lewis PubHsher, Chelsea [10] Gumbricht, T., (1993), Nutrient removal processes in freshwater submersed macrophyte systems, Eng.,page 1-30 ['^UMG^cs\f&E