Tgp chi Khoa hgc Tnr&ng Dai hoc Cdn Tha Phdn A Kboa boc Tif nhien Cong ngh? vd Moi tnrang 28 (2013) i Tap chl Khoa hpc Tru''''dng Oai hoc Can Thci website sj ctu edu vn CHAT LirONG NlTdC TRONG HE THONG N[.]
Tgp chi Khoa hgc Tnr&ng Dai hoc Cdn Tha Phdn A: Kboa boc Tif nhien Cong ngh? vd Moi tnrang 28 Tap chl Khoa hpc Tru'dng Oai hoc Can Thci website: sj.ctu.edu.vn CHAT LirONG NlTdC TRONG HE THONG NUOI CA SAC RAN {TRICHOGASTER PECTORUS) THAM CANH KET HOP V d l BEO TAI Tl/ONG {PISTIA STRATIOTES) Dao Quoc Binh', Lam Nguyin Ngpc Hoa' va Ngo Thuy Diim Trang' 'Khoa Mdi trudng vd Tdi nguyen Thiin nhiin, Trudng Dai hoc Cdn Tha Thong tin chung: Ngaynhdn: 05/05/2013 Ngdy chdp nhgn: 29/10/2013 Title: Water quality variation in the integrated system of intensive culture snakeskin gourami (Trichogaster pectorlis) and •water lettuce (Pistia stratiotes) Td khda: Beo Tai tuang, cd Sac ran, dgm ldn, ty le che phu bi mat Keywords: Pistia stratiotes L, Trichogaster pectorlis Regan, nitrogen, phosphorus, surface coverage ratios ABSTRACT In the traditional earlhem pond culture, water in intensive Trichogaster pectorlis Regan pond culture needs to be renewed by flushing out directly to the adjacent canals, leading to degradation of aquatic ecosystem In order to reuse excessive nutrients, purify pond water and use surface water more effectively, the floating beds of water lettuce (Pistia stratiotes L) at four coverage ratios of 0, 25, 50 and 75% pond surface area were applied The concentration of NHj-N in the water body was low in all treatments while TP concentration was higher in the lower coverage ratios of and 25% Coverage ratios did not affect fish growth except the greatest feeding efficiency in the 25% coverage During 60 days oj experiment, water in the experimental tanks did not require changing, but water quality was remained within a suitable range for normal growth oj Snakeskin gourami Therefore, the study helps to maximize efficiency oj water use and utilize nutrients that contributes to protect the environment and to sustainably manage water resource T M TAT Vdi cdch nuoi iruyen thdng nudc ao nudi cd Sgc rdn thdm canh cdn duac thay mdi bdng cdch thdi trirc tiep hi thdng kenh rach ddn din su suy thodi cita hi sinh thdi thiiy vifc Nhdm tdn dung lu(mg dinh duong thua, ldm sach nudc ao nudi cd vd sd dung ngudn nudc mat hiiu qud hon, cdc be ndi thd beo Tai tugng (Pistia stratiotes L.) v&i mirc che phu 25, 50 vd 75% diin tich bi mdt ao duoc su dyng vd danh gid Ndng NHj-N thdp d tdt cd cdc nghiim thirc, TP cd ndng cao d ty li che phd thdp vd 25% Ty li che phu khdng dnh hudng din su tdng trudng cua cd, ngogi trit hieu qua thuc dn cua ty le che phu 25% Id nho nhdl Trong sudt 60 ngdy nghien citu, khdng cdn thay mrdc cho cd, nhung chdt lugng nudc vdn dugc tri pham vi cho phep cho cd tdng truong binh thudng Qua do, tdng hieu qud sir dung nudc vd tan dung dinh duang, gop phdn bdo vi mdi trudng vd qudn ly bin vitng tdi nguyen nudc GlOfl THIEU Mfit nhiing mfi hinh nufii frfing thiiy sdn bin vihig mang lai hieu qui kinh tl cao d dfing bins sfing Cuu Long (DBSCL) li mfi hinh VudnAo-Chudng-Biogas (VACB) vdi ddi tugng nudi la cd Sac rdn Tgi Viet Nam, nang sudt nuoi ca Sac rdn dgt binh qudn 2.5 tan/1.000 m-/vu (Thiiy san Viet Nam 2011) San lugng ci Sgc ran nudi thim canh cua thi gidi tang tir 21.320 tan nam 1999 den hon 40.000 tin nam 2009, dgt hem 30.000 tin nam 2010 (FAO, 2012) Vdi cdch nuoi fruyin thfing, tugna nudc thai tir ao nufii ca Sac ran mdi Tap chi Khoa hoc Tru&ng Dgi hgc Cdn Tho Phdn A- Kboa hgc Tu nhien, Cong nghi va Moi truang: JS '2013i- 64-72 trudng vdn ldn, khoing 20-30% lupng nudc ao mdi tin thay vi sd ldn thay nudc cung kha thudng xuyen, tir 7-10 ngdy/lan cfao vy nuoi keo dii lir 6-8 tfaang Dl hgn chi d nhilm ngudn nuoc mat tir nudc thii ao nudi cd Sac ran vi dim bio sinh trudng tdt cho cd nghiin ciiu sir dyng be ndi thyc vat kit hgp cac be nufii ci Sac ran tuan hodn kin dugc thuc hien nham hgn che xd thii vd tdi sOr dung ngufin nudc vi dinfa dudng frong bl nufii ca tgo sinh khoi thyc vdt PHU'aNG PHAP NGHIEN CUtJ 2.1 Bo tri thi ngfailm Thi nghiim dugc bfi fri vi thyc hiln tai Khoa Mfii tnrdng & Tai nguyin Thiin nfaien, Kfau 2, Dai hpc cin Tha frong thdng Su dung bl composite (200 cm x 70 cm x 30 cm: ddi x rfing x cao) de nudi cd, thi ngfailm dugc bd tri ngiu nfailn voi nghiim thuc vd lan lap lai Nghiim thiic vdi cac diln tich che phii beo Tai tugng kfaac nfaau lin lugt li 0, 25, 50 va 75% so voi dien tich bl mat eua bl (Hinh 1) Moi be cd thi tich nudc li 0,40 m' vdi mil dp cd thi ban ddu li 70 con/m' Cd dupe cho an Idn/ngay bdng thiic an Aquaxcel 7424 dgng vien nfii (40% dgm ciia cong ty thiic in Cargill-Vill Nam) vdi lugng thiic dn ban ddu Id 5% frpng lugng CO thi ca Sau dd tupng thiic in da dugc dilu chinfa theo khd ning dn ciia cd Chpn 30 tai beo gin ddng dgng ve kich cd cho moi kfaung, can frpng lugng beo ciia moi bl tnrde bd tri thi nghiem Cac tai beo dupe giCr bdi cdc khung lim tir dng nhua PVC G 27 mm, khung cd kich thudc 590 mm x 590 mm va cd ldp luoi bao quanh phia dudi nham franh ci an rl beo vi cac choi non Nudc diing dl nuoi ca li chit thii tii tui u biogas pha lodng vdi nudc may tfaeo ty 11 178,5 m^ chii thii biogas/1-000 m' nudc may dya frln kit qud nghiin ciiu ciia Ll Thj Phirong Mai (2010) Theo ddi lugng nudc bfic hoi lin/tuin va bfi sung them nuoc may Se giiir myc nudc ban diu Ghi nhdn lugng nudc thim vao 2.2 Cdc chi tieu theo doi 2 Chdt luong nudc Miu nudc dugc thu dinh ky mdi tudn di theo ddi bien dpng chdt tugng nude frong he tfadng nudi theo thdi gian Thdi gian thu miu tir 7h din 8h sang Cic chi lieu pH EC DO \ a nhiet dp dupe tgi khu thi nghiem bing may cdm tay nong NH.|-N (dgm amfin), vd TP (tdng lan) dugc phdn tich bing phucmg phdp salicylate va acid ascorbic tuong iing, dya ttieo quy trinh tllu chudn danh gii nudc vi nudc thdi (APHA et al 1998) 2.2.2 Beo Tai tugng Chpn them 30 tai beo gin ddng dang vd kich cfi' vdi beo ldm thi ngfailm, cfaieu ddi tfadn, rl cdn frpng lugng thdn, rl tuoi vd khd (sdy d nhi?t dfi 70*'C din frpng lugng khdng ddi), de xde djiih frpng lugng trung binh ciia beo ban dau Trong thdi gian nghiin eiiu, beo phat frien rat tot vd nhanh Sau 21 thu hoach beo dgt Sau dd, beo dugc tfaufaoacfamfii tudn Moi be thu hoach ngau nhien 20 tai beo, dim tdng so lugng beo mdi sinh ra, chilu dai thin re ciia 10 tai beo chpn ngau nfailn, can ttpng lugng tuoi va khd (sdy d nhilt dd 70°C din ttpng lugng khong ddi) ciia tfain rl lit cd beo thu dupe Cuoi thi nghiim, beo dugc thu hoacfa de tinfa cdc efai lilu sinh trudng nhu sd lugng, ttpng lugng tuoi vi khfi (sdy d nhiet dp 70°C din ttpng lugng khfing ddi), tdc dp tang trudng 2.2.3 Cd Sgc rdn Chpn 28 ci ihl cd Sic rdn Trichogaster pectoralis, Regan cd gifing (3,4-3,6 g/con) gan dfing dang vd kich cd, chieu ddi than, can trpng lugng tfroi ciia timg ci thi vi ghi nhan tdng ttpng lugng cd tfad vio mdi bl, chyp hinh trudc bo tri Trong qui frinh thi nghiem, ghi nhdn sd lupng ca chit, ghi nhgn frpng lugng tucri ciia thiic dn cho ci dn (hdng ngiy) Cufii thi nghiem, cd dupe thu hogch de tinh cac chi tiiu sinh frudng nhu ttpng lugng, FCR, tdc dp tang tnidng, ty 11 sdng Cdc thdng sd theo ddi trin cd dugc tinh todn nhu sau: Trpng lupng ci tang them (g/bl) = ttpng lugng cd thu hoach (g/be) - ttong luang cd ban diu ig/hi) Tdc dp tdng tnrdng binh quan theo (%/ngay) = 100*(frpng lugng cd tdng thim (Kg/be)/(frpng luong cd ban diu (Kg/ngay)*so ngiy nudi)) Toe tang trudng tuong ddi, SGR (%/ngiy) = 100*(Ln(ttpng lupng ci thu hoacfa) - Ln(trpt^ lygng cd ban dau))/sd nudi FCR = trpng lugng tfaiic dn sii dung/frpng lugng ci tang thim Hieu qua thiie dn cho dn (%) = 100*(Trpng lugng ci ting thim /frpng lugng thiic an) Ti le sfing (%) = I00*(s6 ci thu hoach /sd ca ban dau) T^p chi Khoa hoc Innm^Dni hgc Cdn Tho Pbc'in A Kboa hoc Tu nhien Cong ngh? vd Moi tnr&ng: 28 (2013)- 64-7 •J> Jt 31 J " ^^ ^ ;f ^ "a -cr -c: ,-::' ^a' "^^ -a ^:' ,Jfc J .-^la ~"C3 ""X;" " Jfc.Ji -c,- Tap chi Kboa boc Truong Dai hoc Cdn Tba Phan A Kboa bgc Tw nbien, Cdng nghe vd Mdttni&r^: 2S12013): 64-'2 2.3 Phuong phap xd ly so lilu , , ,.Cac chi lieu chat lugng nuac dugc theo doi theo thdi gian vi phan tich phuong sai hai nhan to (Two-way ANOVA) vdi nhin tfi thu I la ty 11 che phii vi nhdn td thii la thdi gian So sinfa trung binh cdc nghiem thiic dya frln kiem dinh Tukey (5%) bdng phin mim Statgraphie Centurion XV (StatPoinL Inc USA) KET QUA VA THAO LUAN 3.1 Ch^t lugng nudc bl naoi ci theo thdi gian Qua kit qud thdng ke phuong sai nhdn td cho thiy cfi sy tucmg tic nhin td ty ll che pfaii vd thcri gian cho cdc chi tiiu theo doi pH vd TP nhung khdng cosy tuong ldc d cdc thfing sfi nhiet dp DO, EC va NH4-N (Bing 1) Tat ca cic thfing so DO, EC va NHj-N bi dnh hudng bdi ci nhin td ty II che pfaii vi thdi gian, tfadng sd nhiet dfi ^^^ ^^ ^^ ^- ^ ^ ^ ^ ^ ^ ^^ • Gia tri tnmg binh ciia cdc thdng sd chdt lugng nud^ ttong dgt thu mdu dugc trinh bay frong Bdng Ty 11 che phu va thcri gian inh hudng din tdt cd cdc tfafing sfi theo ddi ngoai trir nhiet dd .^^^^ ^^^^ ^^ ^^-j ^^ ^ ^ n^em thiic (NT) che phu cd nhilt dp ttimg bmh 25.5-28,l°C va ^d sy biin ddng nhilu theo tfadi gian (p