SCTDUNG C H ^ PHAM VI SINH v A i
D^XCriy BON AO NUOI TOM
PGS.TS Le Thj Hien Thao Khoa Ky thuat Mdl trudng Trudng Dai hge Xay dung
Tdm tat: Nude ta ed tiim nSng Idn di phat triin nghi nudi trdng thu^ san (NTTS). Dae bidt nghi nudi tdm da ed nhimg ddng gdp quan trgng cho vide ehi biin tdm xuat khau vS eho nin kinh ti eda da't nude. Tuy nhidn, qua trinh edng nghidp hoa, hidn dai boa dat nude da gay anh hudng xiu din mdi trudng song.
Trong nudi tdm thSm eanh, van di mdi trudng (MT) ao nudi edn ed nhiiu bat cap, khiin eho nhi/ng ngudi nudi trdng gSp rat nhiiu riii ro. Tinh hinh trdn dat ra cho eae nha khoa hgc nhieu van di ein giai quyit, trong dd cd vide xif ly bun day ao nudi.
Chinh vi vSy, vide nghidn cifu tao ra ehi pham vi sinh vat (CPVSV) di xif ly bun day ao nudi tdm eho phu hgp vdl dieu kidn VN vS gdp phan giai quyit tinh trang d nhiim MT IS vide ISm ein thiit trong diiu kidn thue ti ciia nganh NTTS d nude ta hidn nay.
Summary: Vietnam is a potentially rich country to develop aquaculture.
Especially, shrimp breeding industry has important contributions to the national economy and shrimp product export. However industrialization and modernization process made adverse effects for living environment In shrimp intensive cultivation, the environmental matters of breeding pond face to many dilemma, so breeders meet a lot of risks. Above situation puts for seieniists many problems asking to solve, in which there is mud treatment of shrimp breeding pond. Therefore, research making micro-biological product to treat mud of shrimp breeding pond has to correspond with Vietnamese condition and contribute to solving environmental pollution situation. That is necessary task in actual condition of aquaculture field in our country nowadays.
• Npi dung nghien ciru: dng dung c h i pham VSV trong viee s i n xuat phdn bdn hCru eo vi sinh (PBHCVS) td bun ao nudi tdm sau thu hoach de xd ly bun ao nudi tdm.
1. PHUONG PHAP NGHIEN CCfU + Phuong phap do va phan tich:
Cac phuong phap phd biin, hien hanh dupc sd dung de do dae, phan tich eae thdng sd cd lidn quan d i n chat lupng nude va bun nhu tdng sd VSV, TOC, HjS, tdng N, P, K...
Cac NC dupe tie'n hanh tren 2 16 thi nghiem mdt Id khdng bd sung e h i pham VSV, gpi la Id ddi chdng (DC) vd mpt Id cd bd sung c h i pham VSV, gpi la 16 thi nghiem (TN).
Sau dd tiin hanh phan tieh cac ehi tieu chit lupng nUdc va bun de so sanh hieu qua xd li (HQXL) aida hai 16 DC va Id TN
TAP CHl KHOA HOC C O N G N G H £ XAY DUNG SOOf- 9/2007 129
Bun cdn Qugng nghdo lan
Than bun
(kho, toi) Hdn hpp (d 2 tuan) VSV hieu khi
Rl dudng
Tron deu Bao quan
"
Phdn hdu eo - vi sinh Hinh 1. Quy trinh san xuat PB HC VS
+ Phuang phap lien quan den cdng nghe san xuA PB HCVS tir biin ao: Quy trinh sin xuit:
- Dd« tuOTig n/c: phia Bic: Oinh VQ, Quy Kim (Hai Phdng); phia Nam: My Xuyen, Ca Mau.
2. KET QUA NGHIEN ClJU
2.1 Hien trang o nhilm cac viing ao nuoi tdm: Cac k i t qua phdn tich dupe the hien d bang 1:
Bang 1. Chit lugng bOn dSy tai cac vung nudi tdm eao san nSm 2005 Cbl tidu Don vi
pH HjS TOC Tdng nito Tdng phospho Tong kali Tong Clo"
mg/l
Tdng Na* \
Tdng VSV CFU/g
Dinh Vu 7,5 510 3,14 0,38 0,054
1,13 0,58 1,47 4,2.10'
Quy Kim 7.2 408 3,29 0,23 0,04 0,98 0,70 1.67 1,6.10"
My Xuydn 6.9 206 9.80 0.12 0,19 0,35 0,68 1,55 3,7.10'
Ca Mau 8,5 346 10,90
0,31 0,62 0,99 1,82 1,91 3,6.10' Kit qua phan tich chit lupng nude d cdc ao nudi tdm dupe the hien d bang 2:
Bang 2. Chat lugng nudc tai cSc vung nudi tdm cao san nSm 2005 Chi tidu
Nhiet dp
Dan vi OC pH
DO 06 mudi NH4+
mg/l
%0 mg/l N02-
1
N03- [ COD
P03- t Si
Dinh Vu 32 8,1 5,5 13 0,31 0,02 0,08 101 0,20 0,26
Quy Kim 31 7,7 5,8 14 0,98 0,05 0,43 141 0,46 0,59
My Xuydn 27 7.5 4,2 8,0 0.56 0,046
0,09 37 0.21 0,23
CS Mau 28 7,4 4,5 10 0,46 0,028
0,31 26 0.75 0.68
TCVN 2 5 - 3 2 7,5 - 8,5
> 5 1 0 - 3 0
<0.1
<0,25
<0,25
130 TAP CHI KHOA HOC CONG NGHE XAY DUNG S00f-9m07
2.2 Xi> ly bim ao bing che pham VSV Viet Nam tai PTN: Kit qua nghien cdu xd ly bun ao bing e h i phim VSV Vidt Nam tai phdng thi nghiem PTN dupe dua ra d bang 3.
Bang 3. Cae cbl so phan tich ehat lugng bOn ao nudi tdm duge xifly bang CPVSV eiia VN
Cac ehl tidu Ty Id bun can (%) TOC(%) H2S (mg/l) Tdng VSV (CFU/g)
Trudc thi nghidm
72,5 8,0 520,0 5.10'
Sau thi nghidm Khdng sue khi
Ddi chimg 72,2
7,9 520,0
5.10'
Thi nghidm 61,2
7,1 310,6
6.10'
Cd sue khi Ddi ehirng
61,9 7,5 200,6 4.10'
Tti nghidm 52,0
6,7 129,5 6.10' Cac k i t qua nghien cdu trdn dupe phan tich va tdng hpp va dUa ra so sanh trong bang 4.
Bang 4. So sSnh HQXL bun can d cac mSu TN eiia 2 Id khdng sue khi vS cd sue khi Cbl tidu
Ty Id bdn can TOC HjS Tdng VSV
Khdng sue khi i 1 5 % i 11 % i 40 % T 12 l i n
Cd sue khi i 28 % i 1 6 % I 75 % r 120 l i n
Dp chenh ve HQXL g'tOa miu TN vS DC d Id cd sue khi Tang HQXL 16 %
Tang HQXL 11 % Tang HQXL 35 % Tang sd lupng VSV 15%
2.3 So sdnh HQXL bim ao nuoi tdm cua CPVSV ciia VN va che pham nhap ngoai d quy md PTN
- Sy biin dpng TOC sau 3 tuin xd ly d cac loai c h i pham VSV dupe dUa ra d hinh 2:
6 , —•— Odi chimg
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Hinh 2. Biin ddng cOa TOC Hinh 3. Bie'n ddng eda HjS trong bun ao nudi tdm trong bOn ao nudi idm
Qua hinh 2 ta thay sau 3 tuin, d cac Id cd bd sung c h i pham VSV nhap ngoai, ham lupng TOC d i u giam xudng ddng k i (giam d i n 3,24- 2,76%, chi ed Id DC thi ham IUpng TOC van cao (4,59%). Oiiu dd chdng td cae c h i pham VSV bd sung vao MT cd tac dyng ldm giam TOC va HQXL cda e h i phim VN khdng khac nhiiu so vdi che pham nhap ngoai.
- SU biin ddng tdng hdm lupng HjS trong bun ao nudi torn dugc dua ta d hinh 3.
TAP CHI KHOA HOC C O N G NGHE XAY DUNG sd Of-9/2007 131
Qua k i t qua thi nghiem d hinh 3 ta thay cung tuong ty nhu ddi vdi TOC, cae CPVSV bd sung vao MT ed tac dung ro ret trong viec lam giam H2S - mdt tde nhan gdy doc cho cac lodi TS.
Tdng N, P va K la nhOmg thdng sd phan anh mdc dp dinh dudng cda bun. Th6ng qua cac kit qua nghien ciru da tien hanh, va so sanh sy biin dpng cda ham lupng tdng N, P va K gida eae mau DC va cac mau TN ed bd sung ehe pham VSV, cung njt ra nhan xet: sau 3 tuan thi nghiem, ham lupng tdng N, P, K d eae m i u DC ludn eao hon d cae mau TN co bd sung e h i pham VSV.
Qua k i t qua N/c d quy mo phdng thi nghiem (PTN) cd the rdt ra nhiJmg nhan xdt sau:
a. Thi nghiem xd ly bun ao eo bd sung c h i pham VSV (cd va khdng sue khi") sau 72h eho thay: CP VSV cd tac dung ro ret trong viee xd ly true tiip 6 nhiem bun ao nudi tdm cao san (ehi pham VSV d 16 TN lam giam dang k i hdm lupng TOC, HjS, N, P, K so vdi 16 DC).
b. Thi nghiem so sanh HQXL eda c h i pham VSV1 cua VN vdi mpt sd c h i pham nhap ngoai tdi qua trinh lam saeh bun ao eho thiy:
Trong 4 loai ehe pham VSV dung trong TN, nhin ehung khong quan sat tha'y su khac biet ro ret v i HQXL gida CP VSV cda VN va cac c h i pham eda Pond'clear vd Trung Qudc.
2.4 So sanh HQXL bim ao cua CPVSV cua VN va che pham nhap ngoai d mo hinh ao nudi
Thi nghiem dupc thuc hien nhU md ta trong phan phuong phap. Hai c h i phim dupe lua chpn d i so sanh Id Pond' clear vd c h i pham cda VN.
2.4.1 SlJ bien dpng cua TOC trong bun ao d 16 DC va 2 Id TN sd dyng CPVSV eda Pond' clear va VN dupe dUa ra trong hinh 4:
6
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Hinh 4. Bien dpng ciia TOC trong bOn ao nudi tdm vdi cac loai CPVSV VN vS CP Pond' clear
Hinh 5. Bien dpng ciia H^S trong biin ao nudi tdm vdi cSe loai VSV VN vS CP Pond' clear Qua hinh 4 ed the thiy: sau 10 tuan TN, d 16 DC khdng cho ehe pham VSV, TOC tang manh va dat tdi 5,6%. Trong khi dd d cac Id TN, TOC eh? x i p xl 4%.
2.4.2 Sif bien dpng cua ham luang H,S trong bdn ao cda 16 ddi chdng va 2 16 TN Pond' clear va VN dupe da ra trong hinh 5. Qua hinh 5 ed the thay d Id OC, HjS tdng len d i n 912,5 mg/l d tuan thd 10). Trong khi dd, d 2 Id TN, HjS giam tdi 192 d c h i pham Pond' clear vd tdi 161 mg/I ddi vdi c h i pham VN.
132 TAP CHf KHOA HOC CONG N G H | XAY DUNG SO Of-9/2007
- D i tai eung tidn hanh thi nghiem tuong tu nhu tren ddi vdi ham IUpng tong N, P. K va rut ra nhan xet: d cac Id TN, hdm luong N, P, K trong bun ao ludn cd xu hUdng thap hon d cac 16 DC.
2.4.3 Subien dpng so luang VSV trong cac Id TN & DC: (CFU/g: Colony forming nit/g) Bang 5. Subiin ddng so lugng VSV (CFU/g)
trong cae Id TN khSc nhau tai ao nudi Tuin
T u i n 0 Tuan 2 Tuan 4 T u i n 6 T u i n 8 Tuin 10
CSe loai chd pham VSV Ddi chimg
3,5.10' 5,2.10' 5,1.10' 5,6.10' 3,1.10' 7,1.10'
Pond' tear 2,3.10' 0.9.10' 6,6.10' 2,3.10' 1,9.10' 5,9.10'
Viet Nam 4,7.10' 1,1.10' 4,5.10' 2,6.10' 4,7.10' 5,7.10' NhSn xdt: Qua kit qua TN tien hanh trong 6 ao nudi ngoai trdi eho thay: khi dupc bd sung CPVSV, cac chi sd ly, hoa sinh cda bun ao dupc cai thien rd ret. Dae biet la tai 2 16 TN ed bd sung CPVSV cda VN vd eda Pond' clear, hdm lupng H2S, TOC... luon thap hon d 16 DC, trong khi tdng VSV hieu khi lai eao hon. Day la y i u td r i t quan trpng anh hudng de'n tdc dp nudi tdm.
2.4.4 Hipu qua ctia viec sur dung che pham VSV VN va ngoai nhSp trong xurly mdi trudng doi vdi kha nSng sinh trudng ctia tdm; cac k i t qua NC dupe dua ra d hinh 6, 7, 8:
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Hinh 6. San lugng tdm sau thu hoach Hinh 7. T^ Id sdng eua tdm sau thu hoaeh
NhSn xdt: Mac dd san lupng tdm sau thu hoach vd ty Id sdng eda tdm sau thu hoach d ao cd c h i phim VN thip hon d ao cd Pond' clear, nhung xet khdi lupng trung binh/con thi d Id TN sd dung che pham cua VN lai uu viet hon cua Pond' clear.
2.4.5 Danh gia hieu qua cua che pham PB HC- VSV ten sinh truang cua ciy lua va ngd:
Hinh 9,10.11
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•? 12.5 1
1 1 2 .
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Hinh 8. Khdi lugng trung binh/con tdm sau thu hoaeh
TAP CHf KHOA HOC CONG NGHf XAY DUNG sd Of-9/2007 133
D Bii.n ao ban dau • Thien nong n Dd'i chumg • Thi nghiem
Lda Ngo D Bun ao ban diu • Thien nong DOoi chiimg DThi nghiem
Hinh 9. Khdi lugng rd ciia ngd vS lua Nhan xdt:
T i t ca eae eay trong thi nghiem d i u sinh trudng binh thudng, khong bi chit do anh hudng eda dp man.
- Cdy trdng d chau TN cd c h i phim phan bun HC VSV phat trien tdt, eay map, xanh d i u .
- Su sinh trudng eda eay Ida va ng6 cd bdn che phim HC VSV cd the danh gia tuong duong vdi cay khi sd dung phan bdn Thidn N6ng eda VN.
2.5 Sd bo tinh gia thanh phan biin hiiru cd VS (PB HC-VSV)
Tong chi phh 377.800 6/1 tan san phim.
(Gia thanh chua bao gdm khiu hao thiet bi).
Hinh 10. Chiiu eao trung binh eua ngd va lua
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2.6 Nhan xet kit qua xur ly nen day ao nudi tdm sau thu hoach tao PB HC-VSV - D i tai NC da tiin hanh san xua't thd nghiem c h i pham PB HC-VSV td bdn ao nu6i t6m cao san tren co sd d hiiu khi cd bd sung cac c h i phim VSV hCfu hidu dupc phan lap td bun ao nudi t6m.
- C h i pham phan bdn HC-VSV tren ed chit lupng g i n tUPng dUPng vdi Tieu chuin Nganh do Bp NN va PT NT de ra.
- O i tai da tiin hanh thuc nghiem tren 2 ddi tupng eay ng6 vd cdy Ida cho thiy e h i phim PB HC-VSV s i n xuit td bun ao cd tac dpng tdt den sinh trudng cda cay trdng, tuong tu nhu loai phdn bdn Thien Ndng dang dugc dung phd biin d VN.
3. KET LUAN VA KIEN NGHj 3.1 Kit luan
3.1.1 Xijriy biin ao nudi tdm cao san trong qua trinh nudi
- Cac k i t qua thu dupc tai PTN eho thiy hieu qua xd ly bun ao nudi t6m bing c h i phim VSV rit hCfu hieu. Ddy la mpt minh chdng tdt cho viec sd dung che pham VSV ndy trong vide xd ly tryc tiip d nhiem bun ao nudi tdm cao san trong qua trinh nuoi.
134 TAP CHf KHOA HOC CONG NGHE XAY DUNG SO Of-9/2007
Trong 4 c h i phim VSV (VN, Pond' clear, BZT, TQ) dem TN thi hieu qua xd ly MT cda che phim VN khdng thua kem cac gi c h i pham ngoai nhdp.
- Khi dupc bd sung c h i pham VSV vao ao nudi, cac chi sd ly, hoa, sinh cda bun dupc cai thien rd rang, the hien qua ham lupng H2S, TOC, N, P. K... eda m i u TN ludn tha'p hon miu DC.
Ao cd bd sung che pham VSV cd ty Id tom sdng, trpng lupng trung binh/con va san lupng t6m nu6i eao hon nhieu so vdi ao ddi chimg.
3.1.2- Xirly bun ao nudi tdm cao san sau thu hoach
- Be tdi da NC sd dung CPVSV hOru hieu de san xuit thd nghiem PB HC-VSV. Myc dich eua TN nay la bien bun ao nudi t6m eao san - tae nhan gay 6 nhiem - thanh nguyen lieu chinh de s i n xua't phdn bdn HC-VSV.
- C h i pham PB HC-VS tren cd chit lupng g i n tuong duong vdi TC Nganh do Bp NN va PTNN d i ra.
Budc d i u thuc nghiem tren 2 ddi tupng cay trdng ngo va Ida cho thiy c h i pham PB HCVSV san xuat td bdn ao co tae dpng tdi sinh trudng eua eay tuong tU nhu loai phan bon Thien N6ng hien dang dupe dung phd biin d VN.
3.2 Kien nghi
- Can tien hanh thdng ke lai t i t ca cac c h i pham VSV eda VN va e h i pham ngoai nhap, neu thanh phin, tac dung chu y i u va each sd dung cua tdng loai, gidp ngudi nu6i sd dyng mot each ed hieu qua.
- Cd the xdy dung m6 hinh ao nu6i t6m img dung edng nghe sinh hpe, dung che pham HC-VS de xd ly bun ao, nham tao ra s i n pham thuy s i n c6 chat lUpng cao, bao ve MT va bao dam an toan v i mat ve sinh thyc pham.
Tai lieu tham khao
1. Cac Tap ehi Thu} san tU nSm 2002 - 2005.
2. Khoa thu} san, Trudng DH Cin Tha. Cam nang Ky thuat nu6i Thuy san nude Ip - Nxb N6ng nghiep. Ha Ndi.1994.
3. 66 Thuy san. DU thao Chuong trinh phat trien nudi trdng thuy s i n thoi ky 1999 - 2010.
4. Khoa thu} san, Trudng DH Cin Tha, Bd Thuy san. Quan ly sdc khoe tom trong ao nu6i - Nxb Ndng nhiep. Tai ban lan thd 4. Ha Npi, 2003.
5 Trang Web: www, vasep. com, vn
TAP CHI KHOA HOC CONG NGHE XAY DUNG sdOf-9/2007 ""^S