Tgp chi Khoa hgc Tnrdng Dgi hgc Cdn Tho Phdn A • Khoa hgc Tu nhien Cong ngh? va Mdi nvong 18(20131 17 22 ^ Tap chl Khoa hoc Trirclng Dai hoc Can ThcJ website sj ctu edu vn Sir DUNG PHirONG PHAP THU DU[.]
Tgp chi Khoa hgc Tnrdng Dgi hgc Cdn Tho Phdn A • Khoa hgc Tu nhien Cong ngh?18(20131 va Mdi nvong: 17-2 Tap chl Khoa hoc Trirclng Dai hoc Can ThcJ ^: website: sj ctu edu Sir DUNG PHirONG PHAP THU DUNG D£ SO SANH HIEU QUA KINH TE CAC GIAI PHAP XIJ^LY NlTOfC THAI AO NUOI CA TRA TREN DIA BAN TINH AN GIANG Hoang Thi Thanh Thuy va Le Anh Tuan' ' Khoa Mdi trucmg vd Tdi nguyen Thien nhiin, Trudng Dgi hgc Cdn Tho Thdng tin chung: Ngdy nhdn: 23/5/2013 Ngdy chdp nhdn: 29/10/2013 TUle: Applying Collective Utihiiy Methodfor the economical effectiveness comparison of catfish pond wastewater treatment solutions in An Giang province Tir khda: Ao cd tra, xu ly nude thdi, Phuangphdp Thu dung, tinh hieu qua Keywords: Catfish pond M-astewater treatment Collective Unhiiy Method, effectiveness ABSTRACT An Giang province has recently been facing the problems of declining water quality due to the blooming of intensive aquaculture Four fishpond wastewater treatment systems currently being applied in the province include (1) aeration lagoon with aquatic plants; (2) Sequencing Batc Reactor (SBR) method; (3) microbiological method; arui, (4) high-speed Purolite In this study, the Collective Utility Method was applied to compare the effectiveness of these wastewater treatment systems accordin to five criteria: (a) treatment efficiency: (b) cost per cubic meter of wastewater to be treated; (c) cost of system operation; (d) total area required; and, (e) treatment rate per day The results showed that the SBR system gained advantages in medium-siz fish farm (about 10% of the total fish farming area used for treatment) over the others In the case of having a greater treatment area (greater than 20% of the total raising area), using aeration lagoon ii ith water hyacinth plants could be an alternative TOM TAT Tinh An Giang dang ddi phd vdi vdn de suy gidm chdt lugng nude su bimg phdt thdm canh nudi thuy sdn Hien cd bon hi thdng xir ly nude thai ao cd dang duac dp dyng d tinh An Giang, dd Id (1) ldm ho thodng ket hgp vdi nudi thuy sinh thuc vdt; (2) phucmg phdp xir ly dgng me (SBR); (3) phuong phdp vi sinh; vd (4) diing Purolite toe cao Trong nghien ciru ndy, phucmg phdp thu dung da dugc su dung di so sdn vd ddnh gid cdc hi thdng xu ly ndy theo ndm chi tieu: (a) hiiu qua xu ly; (b) phi ddu lu cho mdi mil khdi nude thdi cdn xu ly; (c) chi phi vdn hdnh hi thdng, (d) td ng dien lich ddt xu ly, vd (e) ldc xir ly mdi ngdy Ket qua cho thdy hi thdng SBR cd uu the han vdi diin tich trgi nudi cd co quy md vira phdi (dimg khodng 10% dien tich ddt cho xu ly) so vdi cdc hi thdng khdc Trudng hgp cd diin lich xu ly rdng han (trin 20% tdng dien tich nudi) thi diing ao thodng vdi cdy trdng la beo luc binh cd thi dugc chonlua Tap chi Klioa hgc Trudng Dai hoc Cdn Tha Phdn.4- Khoa hgc Tu nhien Cong nglie vd Mai Inrong: 28 12013)- /"- © A T VAN ©E An Giang Id mdt Uong cdc tinh cd diln tich nudi cd ci tra, ba sa Idn nhit d ddng bdng sdng Ciiu Long (DBSCL), gdp phin phdt Uiin kinh ti khu vuc va ddng gdp ldn Uong kim nggch xuat khau thuy sin ciia Viet Nam Tuy nhiin, phit triin nudi trdng thiiy sin day die thucmg phdi ddi mdt vdi nhiem mdi tmdng nude vi gia tdng mam benh thiiy san, lira gidm nang suit thu hogch, giy thdt thu hang loat Hien nay, cic vimg nudi chua dugc quy hoach mgt cdch bdi ban, nghi nudi thuy sin phit Uiin mdt each ty phit, ciing li h | qui gay gidm chat lupng ngudn nude mdt miic d nhiem cd liic vugt qud nang ty lam sgch ciia dong sdng Trong qua Uinh nuoi cic chit thai hiiu co, khdng sinh, chit khu trung, thiic dn du thira khdng dugc xii Iy tir cac co sd nudi tham nhap vio radi trudng nude giy d nhilm, bao gdm hiln tugng nd hoa ciia tao ddc vi sy tang sinfa ciia cic sinfa vdt gay binh (Trung tdm Kfauyin nong tinh An Giang, 2003) Khi cac chit thai vdi sd lugng ldn va chit lugng chua dgt theo tieu chuan dugc thai vao mdi truong nude thi cac qud trinh ly, hoa, sinh, dgng hpc ty nhien se tao cdc anh hudng khac den chit lugng d vimg xung quanh (Ddng Nhu Toan, 1997) nhiim hiiu co dugc danh gid bing chi tiiu nhu cau oxy sinh hgc (BODs) Chat hiiu ca thiiy vuc chii ylu la nguon thiic dn thiia va chat thii thiiy sinh vat Chdt thai ldng dpng xudng nin diy tgo thinh chit biin diy thiiy vyc Khi lugng cfadt hiiu ca qud nhilu, qui trinh phin hiiy tieu hao nhilu oxy hod tan thiiy vuc, gay nin hiln tugng nhiem ban thiiy vyc (Dang Ngpc Thanh, 1974) Do sy thilu hut oxy Uong ngudn nude nliilu logi thuy sinh vdt nfau cd, tdm, dpng vit nguyen sinh khd sdng dugc Trong nude va uong ldp can day se dien qud trinh phdn hiiy yira chdt hiiu ca, gidi phdng nhieu ddc cho ngudn nude nhu H2S, CH4— (Trdn Huu Uyin va Trin Vilt Nga 2000) Dl dat muc tieu phat trien nghe nuoi ci tra bin vimg thdi gian qua An Giang dS tl chiic nhilu cupc Hpi thio khoa hpc vdi sy tham gia ciia nhilu nhi khoa hpc vd cac doanh nghiep chuyen vl nghiin ciiu Uong linh vuc xii Iy nude thai di mong tim giai phdp xd ly nude thai tir cac ao nuoi ci tra dgt hieu qua, phii hgp dilu kiln ciia dja phuang Sd Tai nguyin vd Mdi trudng tinh An Giang da cd quy dinh tam thdi uong ngudi din chua tim dugc gidi phdp xii ly nude thai thich hgp thi buoc phdi chita mdt diln tich toi thilu li 25% trin tong diln tich mat nude nudi dl xii ly sa bg nude thii tnrde thii ngudn nude mat xung quanh Giii phap niy hiln da sd ngudi dan khdng chip nhin hp CO gang tin dung diln tich cho hoat ddng nudi, Uong dilu kien gia dit kha cao, nen phin ldn khong muon bd mdt phin diln tich tuang doi ldn dl xii ly nude thai tmdc cho chdy mdi tmdng theo khuyin cdo Hi^n tinh ciing da dua vao dp dung thii nghiem mpt sd phuang phap xis ly nude thai ao nuoi ca tra de tren co sd img dung nhan rdng Uong tinh Van de hiln la cde phuang phap chua dugc danh gia mdt each cy thi tinfa uu viet ve cdng nghi va ca kinh tl dl lim ca sd khuyin cao ngudi dan ap dung Do viy, dya vio cac bien phdp xu ly ao cd hiln dang dugc dp dung d tinh An Giang, viec xic dinh bi|n phip hihi hieu nhat vdi tieu chi xii ly nude tuang ddi hiiu qua, gidm chi phi dau tu ban ddu It tdn chi phi van hinh (nhan cdng va nang lugng), giam thieu diln tich dit cho xii ly la muc tieu kinh tl - kJ thu^t cho de tai PHirONG PHAP VA PHU'ONG TIEN Dl phin tich cho giii phip can can nhdc va lya cfagn, de tai da ap dyng phucmg phap thu dyng (Collective Utility Method), dugc nha toan hpc Lesoume phat triln tir nam 1964, vl sau dugc sii dung Uong nganh tdi nguyin nude (Dupnick, 1970) Diy la bai toan kinh tl theo thu^t phan tich ma tran giiip cho vile lua chpn phuang in ldi uu cac du an da muc tieu Dau tu he thdng xii ly nude thii ao nuoi ca dugc xem nhu mdt dy in vi dy in thudng phyc vu cho nhieu muc tieu khac nhau, ket qua deu nham vao lgi ich cao nhit cd thi dgt dugc cho ddi tugng cdn dau tu Cdc muc dich ddi bi rang budc, ban che lin nhau, ddi hdi ngudi dilu hinh chung phii cd rapt quylt dinh tdi uu Do cic muc tieu khdc nhau, ky hieu Z,j, (hi?u qud xii Iy, cfai phi ban diu, chi phi van hinh, di|n tich dat) nin don vi tinfa kfadc nfaau, phuang pfadp tfau dung sii dung cdng thiic sau de chuyin cic gid Ui cd sd thii nguyin khdc gia tri khdng thii nguyen Chuyin Zy d timg hang chi sd kfadng thiir nguyin b,j Z„ -minZ, maj2, -minZ'„ (min bij = 0; max bfj = 1) Dinh U 11 gia trpng Uj (0 < a, < 1) theo mitc quan trgng ciia muc tiiu qua lay y kiln chuyin gia va ngudi dan LTng vdi mdi bi?n phap xii 1> ip Tap cfii Klwa hoc Trudng Dai hgc Cdn Tlia Phdn A • Kfioa hgc Tu nhien Cdng ngAf va Mm truong: dung cdng tfaiic tinh gia tri thu dung CU, Sap thii tu giim din ciia CU, roi chpn gii tri ciia (CUi) tiiy theo muc tieu tii thiiu hod chi phi xii ly dl dat yeu cdu chat lugng nude CU, = Iaj*b.j Yie tai chpn dja diim nghien ciiu la tai 04 ao nuoi cd tra cd dp dung bien phdp xii ly nude thai vdi cac bien phip xii Iy nude thii kfadc nfaau tai cic dia ban thugc tinh An Giang, cu thi nfau d Hinh I vd tdm tit nfau d Bang B A N D V! TRI TTHU M A U - Ky hieu VI trf thu mSu - Olml xa Long Giang, huyen Cho lJa\ tinh AG Di^m2: xa Phu ThuSn, huyen Thoai Stin, tinh AG O l n n xa VTnh Bmh, Ch&u Thanh An Giang DSTTA >3 Hoa Bmh Thanh, Ch&u Thanh, tinh AG H C T H A P Hinh 1: Ban vj tri nghien cuu Bang I: SI lugng va dien tich mat nude cac ao lua chpn nghien cuu Kfau nuoi ca tra Khu nuoi ca tra Kfau nuoi cd tra Kfau nuoi cd tra giong Thong so tgi xd Phu Thuan tai xa VTnh Binh tai xa Long Giang Hoa Binh Thanh_ Ky hieu (Ao HBT) (Ao PT) (Ao VB) (Ao LG) Sd ao nudi (cdi) 19 Diln tich mat 112.400 2.000 nude nuoi (m-) khuay Qua trinh niy nfaam lam dn dinh nude thii - Ao PT nuoi cd tgi xa Phu Thuan, huyin dilu hoa cic thdnh phdn cd Uong nude thai cung Thogi Son ciia Cdng t> Thiiy san Nam Bd ap dung nhu ndng chat d nhiem trudc dua qua be xti xii ly nude thii bang phuang phdp vi sinh Hd nudi ly chinh cd dl cic sgi nhua tdi chl lam gid the dpe khoanh radt viing diln tich khoang m- Uong ao theo chieu dii ciia bl Cudi ciing nude dua sang bl nuoi, phia dudi cd Idt bgt nylon, ca tap tmng den ling de Idng Uong nude thdi tmdc thai kinh diem in he thdng xu Iy bd tri may bam nit npi ddngnude tir diem niy va bam vdo bdn chiia day nude thdi dugc khuiy iron nhd ldp dgt bam canh Top chi Khoa hgc Tnrdng Dai hgc Can Tho Phdn 4: Kfioa hoc Tu nhien Cdng ngfie vd Mdi tnt&ng 28 '20/3/ "• nhdn bdng phieu dilu tra kit hgp khao sdt thue t i Phdng v i n lanh dao, can bg mdi trudng vd hp nuoi cd, npi dung v l ddnh gia miic dp quan Upng cua c i c y i u td liln quan d i n quyit dinh d i u tu he t h i n g xii ly nude thai (do ddy la c i c ddi tugng cd tinh chat q u y i t dinh n i n chi tiin h i n h d i i u tra 03 phieu/nfadm ddi tugng, tdng cpng phieu) A o VB nudi cd Ua tai xd Vinh Binfa, huyen Chdu Thanh ciia Cdng ^ Vilt An Qud Uuih xir ly n u d e bdng hd sinh hgc thyc vdt noi gdra luc binh, beo v a lau say c h i l m 1/3 dien ticfa hd ddng thai cd thd nudi ca tap Cudi cimg nude ty chdy qua lam t h o i n g nhan tao ddng tfadi cd bd tri may khuiy trdn be radt A o LG nudi cd tra tgi xa Long Giang, huyen C h g M d i cua ong V u o n g Binh Thanh, gdm mpt day ao nudi vdi trpng lugng cd t h i nudi k h i c N u d e tiiii tap t m n g vdo mdt m u o n g thodt n u d e chung va dan hd cd l i p dgt he thdng xii ly nude thdi theo p h u a n g phdp dang m l K E T Q U A VA T H A O LU4.N Cdng nghe xu ly vd cdc y i u td cd liln quan den van hanh he thdng xit ly nude thii tgi c i c ao nudi ca ehpn nghien ciiu dugc Uinh bdy Uong B i n g K i t qud pfaan tich mdu nude thai ao nudi ed t m d c qua he thong xir ly nude thai dugc trinh bay Uong B i n g Hiiu suit xii ly cac chi tiiu d nhiim ciia 04 he thong xii 1^ ao nuoi cd chpn nghiin ciiu dugc t h i h i l n Uong Bdng Cac muc tieu liln quan d i n quyet dinh d i u tu he thdng xOr ly nude thii ao nuoi c i tra dugc Uinh bay Bdng Nliu trinh bdy d phin Uen, mdt h | thdng xu ly nude thai ao nuoi ca Ua hieu qua la h? thdng phii dap iing mgt so myc tiiu c a ban (1) Chi phi d i u tu thdp; (2) Chi phi van hanh thap; (3) Dien tich c i n cho bd Ui he thdng xii ly ft; vd (4) H i | u suit xii ly cao (ty 11 lai chua xir ly dugc phai thdp) A o H B T nuoi cd tra giong Hda Binh Thanh, tiiugc Trung tam g i i n g thiiy san tinh An Giang N u d e thai dugc xii ly b i n g p h u a n g p h i p Purolite tdc cao Ddy la phuang p h i p xir ly cao phdn tii, cdc chdt d nhiem lo liing hay hoa tan nude sau xit ly bdng cac hoa chit se ldng xudng ddy va se d u g c logi ngodi, phin nude se dugc tii tuan hodn vdo ao nudi cd Cac chi tiiu d n h i l m nude dugc chgn d l d i n h gia Uong n g h i i n ciiu la: Nhu c i u oxy sinh h o i (BOD5) nhu c i u oxy hoa hgc (COD), tdng c h i t rdn lo lirng (TSS), Ammonia-nitrogen (N-NH3), tdng dgm (TP), tdng lan (TP) va t i n g sd CoIiform/iOO mL M i u nude thai tir c i c ao nudi ca trudc xii ly dugc thu ngay'tgi diem t i l p nhdn nude thai ciia he thdng xir ly; mau nude thai sau dd dugc xir ly qua he thdng xii ly nude thii dugc thu d i u ciia he thong xii ly nude thdi Thu m i u nude thii t m d c vd sau xii ly tCr thdi diem thang n i m 2009 d i n thdng 12 n i m 2009 vdi thdi gian ngdy thu mau mdt ldn, tan sudt 11 ldn (mau nuoc phin tich 03 lan ldp lai rdi ldy t m n g binfa) Trin thuc t i , he t h i n g xii ly nao cd chi phi d i u tu chi phf vdn hanh, diln tich xii ly, thdi gian xii Iy cGng nhu ty le khdng h i i u q u i ^ h i n cdn lai chua xii ly dugc) cang thap thi he thdng xii Iy dd c i n g cd hieu qud Tuy nhiin, ca 04 he tfadng xii ly d i u cd thdi gian xii ly nhu (01 ngay) n i n chi tiiu khdng dua vao qua trinfa tinh toan hieu qua kinh te De lap cac budc tinh theo phuang p h i p thu dung, c i n xac dinh cac myc tiiu theo Bang Ket qua tfnh gid tri thu dung theo timg phuang phap x u ly nude thai ao nudi ca tra dugc Uinh bdy tai Bdng Sii dung p h u a n g p h i p phong van tryc tilp c i Bang : ThdDg tin ve cac faf t h o n g x u ly nirde thai d a n g a p d u n g tai cac ao nudi Yeu to Cdng nghe xu ly nude thai Tong chi phi dau tu he thong Tong lui?ng nuac thai x u ly Phi nhan cong Phi dien va hoa chat Phi bao duong Chi phi Idiac Thoi gian xu Iv D o n vj Kfau nuoi ca t r a Kfau nuoi ca t r a tai xa Pfaii T h u a n tai xa Vinh Binh Ho l i m thodng k i t hgp thyc vat Trieu dong mVngay dong/thang dong/m-' dong/nam ddng/nSm n.eay Phucmg phap dgng m l K h u nudi ca tra tai xa L o n g Giang Phuang phap vi sinh K h u nuoi ed t r a g i i n g Hoa Binh T h a n h Purolite toe dp cao 200 395 330 52 44.960 25.000 400 750 1.000.000 1.500.000 l.SOO.OOO 4.050.000 1.500.000 8,45 1.875.000 1 340 0 480 78.000 I Phdn A Khoa hoc Ttr nhien Cong ngbe Sloi tnrdng- 2S {20 lii: 11-22 r