Tap chi Khoa hoc va Cong nghe biln T9 (2009) Sd 1 Tr 34 45 CHAT LI/OTVG MOI TRUOTVG D A M THUY TRIEU, K H A N H HOA LE THI VINH Tdm tdt Cdc kit qud khda sdt trong 2 ndm 2005 2006 cho thdy chdt luang m[.]
Tap chi Khoa hoc va Cong nghe biln T9 (2009) Sd Tr 34 - 45 CHAT LI/OTVG MOI TRUOTVG D A M THUY TRIEU, K H A N H HOA LE THI VINH Tdm tdt: Cdc kit qud khda sdt ndm 2005-2006 cho thdy chdt luang mdl truang nudc ddm Thuy Trliu vdn khd tdt mac dit hdm lugng ciia ammonia, nitrate vd phosphate CO lite vugt qud glal hgn cho phep (GHCP) ddi vdi nuac nuoi trdng thiiy sdn (NH34-N: 70 fig/l; NO3-N: 100 pg/l; PO4-P: 15 Mg/l) vd hdm hcgng oxy hoa tan (DO) dot thdp han gid tri tdi thiiu (5 mg/l) Gid tri cua cdc thong s6 khao sdt co phgm vl dao dgng nhu sau: vgt la lieng tic 22,2 din 45,2 mg/l; DO tit 4,8 din 7,40 mg/l; COD tic 15,3 din 37,3 mg/l; NO, tic 0.3 din 5,0 pgN/l; NO3 tit 44 din 155 /igN/l, NH34 tic din 84 fxgN/l; PO4 tic 3,6 din 25,6 ngP/l; SIO3 tic 232 din 1464 ngSt/l; N huu ca tic 436 din 786 pcgN/l; P him ca tic 27,5 din 44,5 ligP/l Trong trdm lich, hdm lugng cdc chdt hUu ca a mice trung binh (Carbon hiiu ca tic 0,1 din 1,3 %; N hihi ca tic 70 din 1294 fig/g vd P tdng s6 tic 16,3 din 716 fig/g) chdt hicu ca nguon goc luc nguyen chiem uu the So sdnh vdi cdc kit qud nghien cicu cdc ndm 2002-2003, co the thdy chdt lucmg mdl trudng ddm hdu nhu khdng cd su thay ddi ldn trie hdm luang ciia ammonia cao vdo thdng 10/2003 (toi 296 figN/l) I Md DAU Dim Thiiy Tridu, dugc gidi ban bdi eae kinh 109°09T14" ddn 109°12'395" Ddng va cac vT ll''59'239" ddn 12°07'009" Bic, thuge huyen Cam Lam va thj xa Cam Ranh, tinh Khanh Hda Dam ed be ngang rat hep (chd hep nhat ca 250 m) va sau khdng ldn (dudi met) Cac boat ddng kinh te dien dam va chung quanh dam kha sdi ddng va da dang Phia Ddng Bac ciia dam la nai cd hoat dgng khai thac va xuat khau cat trang Cac cang dang boat ddng tai dam gdm cang hang hda Ba Ngdi, quan cang, cang ca va cang khai thac va xuat khau cat trang Cac hoat ddng cdng nghiep gdm nha may dudng va cac nha may che bien thiiy san nam dgc theo bd Tay ciia dam Nudi trdng thiiy san phat trien manh d khu vuc phfa Tay ciia dam Theo thdng ke eiia Sd Thiiy san Khanh Hda (2006), nudi bien xung quanh dam bao gdm nghe nudi tdm sii, tdm chan tring, ca mii, ea chem, dc huong ) dugc trien khai vdi qui md kha ldn (ca 400 ha).Trong dim, nghd trdng rong Sun (ea 100 mat nudc), nhuydn thd (25 ha)., eiing phat triSn, san lugng danh bat ca khoang 1000 tan Trong tuong lai, nha may ddng tau se di vao boat ddng khu vuc dam Cd the ndi, dam Thuy Trieu la mgt cae vuc nudc cd anh hudng quan trgng 34 den kinh te ciia tinh Khanh Hoa Vi vay, chit lugng mdi trudng cua dam can dugc quan tam mdt each dung muc Cac nghien cuu ve chat lugng ciia dam da dugc tien hanh vao cae nam gin day (2002, 2003; Pham Van Thom et ai, 2006) cho thiy chit lugng mdi trudng nudc dam Thuy Trieu - vjnh Cam Ranh nhin chung van edn kha tdt Vdi muc dfch tiep tuc theo doi, cap nhat chat lugng mdi trudng dam Thiiy Trieu, bai bao nay dua tren sd lieu cua hai dgt thu mau nudc va tram tfeh da dugc thuc hien dam vao thang 10 nam 2005 va thang nam 2006 khudn khd de tai "Nghien ciiu ngudn Igi va cae giai phap khai thac hgp ly loai Mdng Tay va loai Gia Bien tai dam Thiiy Trieu - Cam Ranh" va tham khao cac sd lieu khao sat thdi ky 2002-2003 II pmroTVG PHAP NGHIEN cutj Thu mau: Cac vj trf thu mau nudc va tram tfch dugc trinh bay hinh 1, eac tram thu mau tap trung d phan Bac dam Thuy Trieu Mau nudc dugc thu vao liie trieu thap va trieu cao tai tang mat Mau tram tfch duge thu true tiep bang dng nhua ed dudng kfnh 5cm, dai 40 cm) Cac cot mau cd be day thay ddi tii' den 36 em; mdt sd cdt mau dugc ehia eac mau nhd cd su khac biet ve hat Tat ca cd 32 mau nudc va 27 mau tram tfch thu dugc vao thang 10 nam 2005 va 31 mau nudc, 23 mau tram tfch thu dugc vao thang nam 2006 Cac mau nudc va tram tfch dugc thu, xii ly, bao quan va phan tfeh theo eac phuong phap tieu chuin hien hanh (APHA, 1995 va FAO, 1975) Xir ly mau: Mau nudc: Mau phan tfch nitrite va phosphate: dung 1ml dung dich HgCl2 (4g/l) cho mdi lit mau Mau phan tfeh nitrate, ammonia, COD: dung 1ml dung djeh H2SO4 dam dac cho mdi li't mau Mau tram tich: dugc bao quan lanh cho tdi phan tfch 35 Cam Tan 12.1- BIEN DONG 12.05- Cam Diifc ^ i 12- 11.95—' 109.15 109.2 109.3 Hinh 1: Vi trf cae tram thu mau nudc va tram tfch Phan tich mau: a Mdu nuoc: pH dugc bing may chuyen dung COD su dung phuong phap oxit hda dung hdn hgp sulfochromic, lugng elorua dugc che bang HgS04, trj gia COD dugc tfnh tii' lugng K2Cr207 tieu tdn Nitrite dugc phan tfch bing phuong phap trac quang phiic mau hdng (phuc eiia nitrite vdi a-naphthylamine va acid sulfanilic) Nitrate dugc khu nitrite qua edt khu Cd ma Cu va phan tfch theo phuong phap xae djnh nitrite Phosphate va Silicate dugc phan tfch bang phuong phap xanh molybden N huu ea (Nhe) dugc phan huy bang phuong phap Kjeldahn va ammonia tao dugc xae dinh bang phuang phap xanh indophenol P huu ca (Phe) dugc xae dinh bang each khoang hda mau nude va phan tich phosphate tao bang phuong phap xanh molybden b Mdu trdm tich: Carbon hiiu ca (C he) dugc phan tfch bang phuong phap oxid hda diing hdn hgp sunfo-chromic N he duge phan tich theo phuong phap Kjeldahn P tdng sd (P ts) dugc xae dinh bang each dun mau tram tfch vdi hon hgp acid manh, phosphate tao dugc xae dinh bang phuong phap xanh molibden 36 III KET QUA NGHIEN CUtJ Chat lugng mdi truong dim Thiiy Trilu vao mua mira Mdi trudng nu&c: Ket qua phan tfeh cac miu nudc dgt khao sat miia mua (10/2005) dugc thdng ke bang va minh hga d hinh Qua bang 1, hinh va ket hgp vdi eac tieu chuan nudc thuy san cua Viet Nam, Ddng Nam A va Trung Qudc thay rang: Cac thdng sd ca ban: gia tri cac thdng sd pH, vat la liing (vat LL) ludn nam gidi han cho phep (GHCP), oxy hda tan (DO) hiem thap hon gia trj tdi thidu (5 mg/l); due thap Ham lugng DO cd xu the thap hon vao liic trieu thap gia tri due, vat la liing va COD ed xu the bien ddi ngugc lai Ham lugng mudi dinh duong: Nitrit ludn thip hon GHCP ammonia, nitrate va phosphate ddi cd gia tri kha cao (thudng gap tai khu vuc dinh dim) va vugt qua GHCP Ham lugng cua silicate dao ddng pham vi rdng Ham lugng eac mudi dinh duong thudng cao d khu vuc dinh dam Ham lugng cua tat ea eae mudi dinh duong thu dugc liie trieu thap thudng cao hon so vdi trieu cao Ham lugng ciia Nhe va Phe khdng cao Cac gia tri ciia yeu td thu dugc vao liic trieu thap cung cao hon so vdi trieu cao Bang 1: Chat lugng mdi trudng nudc (thang 10/2005) Trieu Gia pH tri CAO THAP Do due NTU Vat LL COD NO2N NO3N NH3,4- PO4- SiOsNhe N P Si (mg/l) (mg/l) (mg/l) (Hg/1) (llg/1) (lig/1) (^g/1) (Hg/1) DO Phe (Rg/l) ([ig/l) TB 7.95 4.0 34.5 6.36 17.56 2.3 53 37.0 13.2 735 569 35.9 CT 7.90 2.0 22.1 5.44 15.00 0.5 44 6.0 10.1 373 436 27.9 CD 7.98 6.0 45.0 7.32 20.50 3.5 83 84.0 19.1 1286 695 42.0 n 16 15 16 16 16 16 16 16 16 16 16 16 TB 7.75 5.06 36.2 5.60 21.53 2.6 68 34.6 16.6 843 641 39.7 CT 7.61 3.00 24.3 4.80 19.00 0.3 46 8.0 11.6 465 495 30.5 CD 7.86 7.00 45.2 6.68 27.50 4.0 155 61.0 25.6 1464 786 44.5 16 16 16 16 • 16 16 16 16 16 16 16 16 6,58,5* - 50* >5* - 55** 100*** yQ** j5** - - - n GHCP TB: trung binh; CT: Cue lieu; CD: Cue dgi; n: sd mdu; * tieu chudn nudc Thiiy Sdn Viet Nam (TCVN) ; **: tieu chudn nudc Thiiy Sdn Dong Nam A; ***: tieu chudn nudc Thiiy Sdn Trung Qudc 37 Ham liro'ng ammonia va phosphate (10/2005, tridu cao) N03-N 100 Ham lipo'ng nitrate va silicate (10/2005, tri§u cao) Si03-Si • 1500 80 •• • •1200 900 60 40 + 4- 600 20 •I- 300 0 10 11 12 13 14 15 16 NH3-N (yg/l) NH3-N (MQ/I) ] N03-N (pg/l) —— P04-P (pg/l) Ham lipo'ng ammonia va phosphate (10/2005, trilu thip) I N03-N 1011 1213141516 —.— Si03-Si (pg/i) Ham lipo'ng nitrate va silicate (10/2005, trilu thip) 10 1112 13 14 15 16 —•— P04-P (pg/l) I N03-N (pg/l) 101112 13141516 -'g/g) 108 22.78 6.52 16 55.30 258 27 27 Pts Ti sd moi N/P 5.94 2.42 29.87 27 TB: trung binh; CT: Cue tieu; CD; Cue dgi; n; sd mdu Chat liroTig moi trudng dam Thiiy Trieu vao mua kho Moi tru&ng nu&c: Kdt qua phan tfch eae mau nudc thu dugc vao mua khd (4/2006) dugc thdng ke bang va minh hga d hinh 38 Bang : Chat lugng mdi trudng nudc (thang 4/200()) Trieu Gia pH tn CAO Vat NOz- N - NH3,4DO COD N N LL N NTU (mg/l) (mg/l) (mg/l) (^g/0 (Hg/1) (^g/1) Do due PO4- SiOj- P Si N he Phe (Mg/I) (Mg/l) (Hg/1) (Hg/i) TB 8.07 3.6 31.4 6.84 24.9 2.6 56 9.8 12.0 423 507 32.5 CT 7.97 2.0 29.6 5.94 18.3 1.8 49 0.0 5.3 232 467 27.5 CD 8.17 5.0 33.6 7.40 29.8 4.3 69 46.0 20.3 736 580 37.5 n 16 8.03 16 3.9 16 32.6 16 6.49 16 30.9 16 3.3 16 60 16 TB 2.3 16 11.1 16 438 16 585 16 37.2 CT 7.95 2.0 29.9 5.76 23.3 1.8 53 0.0 3.6 233 487 32.5 CD 8.17 5.0 34.3 7.20 37.3 5.0 69 20.0 23.1 756 684 42.2 n 15 15 15 15 15 15 15 15 15 15 GHCP - 50* >5* - ^c** 15 100** 15 6,58,5* 70** 15** - - - THAP * TB: trung binh; CT: Cue tieu; CD; Cue dgi; n; sd mdu: * tieu chudn nudc Thuy Sdn Viet Nam; **: tieu chudn nudc Thiiy Sdn DdngNam A; ***: tieu chudn nudc Thiiy Sdn Trung Qudc Ham lu'crng ammonia va phosphate (4/2006, trilu cao) Ham lu'O'ng nitrate va silicate (4/2006, trilu cao) N03-N 100 T Si03-Si J 1500 •• 1200 80 •• 60-ff 900 40 600 20 f 300 0 I NH3-N (pg/l) 1011 121314 15 16 12 1011 1213141516 —— P04-P (pg/l) I —.—Si03-Si(Mg/l) Ham lu'O'ng ammonia va phosphate (4/2006, trieu thap) NH3,4-N P04-P 100 J J 30 •25 80- •20 60•15 40•10 20•5 N03-N (Mg/l) Ham lu'O'ng nitrate va silicate (4/2006, trilu thip) •/V .V^V\ : n II.n 10 11 12 13 14 15 16 23 CZZI NH3-N (Mg/l) 1=1 N03-N (Mg/l) —•— P04-P (|jg/l) 1011 1213141516 —»— Si03-Si (pg/l) Chii thich: cdc sd 1,2,3 chi ten cdc trgm Hinh 3: Ham lugng eiia mgt sd eac ydu td tai cac tram (mua khd) 39 Cac din lieu bang va hinh eho thiy: Cae thdng sd ca ban: gia tri cac thdng sd pH, vat LL va DO ludn nim GHCP ; due thap Ham lugng DO cd xu the thap hon vao liic tridu thip gia trj due, vat la lung va COD ed xu the bien ddi ngugc lai Ham lugng mudi dinh dudng: Nitrite, nitrate va ammonia ludn thip hon GHCP phosphate ddi cd gia tri kha cao va vugt qua GHCP Ham lugng cua silicate khdng dao dgng nhidu Ham lugng cda tit ea cac mudi dinh duong thu dugc liie trieu thap eung thudng cao hon so vdi trieu cao trii' trudng hgp ciia ammonia Ham lugng ciia N he, P he khdng cao va cd gia trj cao hon vao liic trieu thip So sanh kdt qua phan tich mdi trudng nudc dam Thiiy Trieu qua dgt khao sat (bang 4) cd thd thiy la chit lugng mdi trudng nude dim Thiiy Trieu vao thang 4/2006 (mua khd) khdng khac nhidu so vdi thang 10/2005 (mua mua) Tuy nhien, vao thang 4/2006 gia tri DO va COD hai cao hon liic ammonia va silicate thap han so vdi thang 10/2005 Vao mua khd, nudc dim Thuy Trieu ft bi anh hudng ciia ddng nudc nggt luc dia mang theo cac chat gay nhiem ban tu lue dia so vdi mua mua Bang 4: So sanh chat lugng mdi trudng nudc qua dgt khao sat Miia Gia pH tri Do due VatLL DO NTU (mg/0 (mg/0 COD NO2- NO3- NH3,4- N N N (mg/l) Oig/1) (ng/1) Oig/1) PO4P SiO,Si Nhe Phe (Hg/1) Oig/1) Oig/1) O^g/l) MU'A TB 7.8 4.6 35.3 5.98 19.5 2.4 60 35.8 14.9 789 605 37.8 (10/05) CT 7.6 2.0 22.1 4.80 15 0.3 44 10.1 373 436 27.9 CD 7.9 7.0 45.2 7.32 27.5 4.0 155 84 25.6 1464 786 44.5 n 32 31 32 32 32 32 32 32 32 32 32 32 KHO TB 8.0 3.8 27.8 6.67 25.7 2.9 58 6.2 11.6 430 545 34.8 (4/06) CT 7.9 2.0 18.3 5.76 18.3 1.8 49 3.6 232 467 27.5 CD 8.1 5.0 37.3 7.40 37.3 ' 69 46 23.1 756 684 42.2 n 31 31 31 31 31 31 31 31 31 31 31 31 TB: trung binh; CT: Cue Heu; CD; Cue dgi; n; sd mdu Xu the bien ddi theo pha trieu ciia eae yeu td dgt khao sat eung tuong tu, nghTa la gia tri (ham lugng) ciia hau hdt cac yeu td deu eao ban vao liic trieu thip triitrudng hgp ciia ammonia vao thang 4/2005 Tuy nhien, miic khac biet vd ham lugng eiia cac yeu td khao sat giQa pha trieu la khdng ldn lim Vao liie trieu thap nudc dim thudng phai tiep nhan eae ngudn thai (bang 5) tir eac hoat dgng ven bd (nudi trdng va chd bien thiiy san, hoat dgng ciia nha may dudng, ) dua nhieu hon so vdi liic trieu cao Do dieu kien tu nhien, dim Thiiy Trieu (nude ndng) nen kha nang trao ddi nudc giua 40 dam va ngoai dim la tuong ddi ydu, nhit la d khu vuc dinh dim (Bui Hong Long va Pham Van Chung, 2006) Bang 5: Thanh phin cua nude thai tir mdt sd ngudn thai a Nirdc thai ciia nha may dudng Cam Ranh sau da xii' ly Thai gian pH 5/2005 3/2006 4/2006 8.46 8.38 8.26 VatLL (mg/l) 56.0 34.0 41.0 BOD5 (mg/l) 23.3 9.3 8.2 COD (mg/l) 250.0 49.0 58.5 Tdng P TdngN (^ig/l) 4860 1981 1900 1894 194 109 b Nudc tai mdt sd ao nudi ca mii tai xa Cam Diic (10/2005) Thdi gian tha A o l 5/2005 A o 6/2005 A o 5/2005 pH 8.1 7.7 8.1 BOD5 (mg/l) 7.0 6.2 6.0 NH3 4-N (lig/) 40.4 62.0 56 NO2-N (lig/1) 7.6 8.4 4.8 NO3-N (Hg/l) 62 57 66 PO4-P (lig/1) 20.3 50 25.6 Moi tru&ng trdm tich Ket qua phan tfch eae cot tram tfeh (be day thay ddi tii' den 30 cm) vao dgt khao sat thang 4/2006 (bang 6) cho thay ham lugng cac chat hu'u ca d muc trung binh (nhung eao hon dgt thang 10 nam 2005, bang 2); ti sd C/N cung van kha ldn, cac ti sd N/P cung tuong ddi eao Tuong tu nhu dgt khao sat thang 10/2005, dinh dam ia khu vuc cd su tap trung cao nhat cua N he va P ts Nguyen nhan chinh cua hien tugng ed the la kha nang trao ddi nude tai khu vuc dinh dam ia yeu nhat va cac vat chat huu ca vao dinh dam tii' khu vuc lien ke da dugc tfch tu xudng mdi trudng tram tfch Bang 6: Chat lugng mdi trudng tram tfch (thang 4/2006) Gia trj Che Nhe Pts TB CT CD n (%) 0.51 0.15 1.30 23 (\^g/g) 343 81 1294 23 (\^g/g) 111 50 716 23 Ti sd moi C/N Ti sd moi N/P 27.44 3.70 114.43 23 4.11 3.17 4.94 23 TB: trung binh; CT: Cue lieu; CD; Cue dai; n; sd mdu Dien bien chat lirong moi trudng dam Thiiy Trieu So sanh vdi ket qua nghien cii'u tai dim Thuy Trigu trudc day (thdi ky 2002-2003; Pham Van Thom et al., 2006), cd the thiy ring chit lugng mdi tru'dng cua dim khdng cd su thay ddi ldn, tru ham lugng ammonia vao thdi ky 2002-2003 (bang 7) rit cao vao mua 41 mua (tdi 296 ^igN/l) so vdi thdi ky 2005-2006 (35,8 ngN/1 vao mua mua va 6,2 |igN/l vao miia khd) Dieu cd the dugc giai thfch la thd'i ky 2002-2003 nha may dudng Cam Ranh (bat dau di vao san xuat vao khoang 2001) chua co he thdng xu ly nudc thai Tinh trang xa nudc thai chua xu ly ciia nha may ed th6 la mgt cac nguyen nhan gay ham lugng cao ciia ammonia khu vuc ven bd Tay Nam dim vi kha nang luu thdng nude ciia dam nhu da trinh bay d tren la khdng ldn Tinh trang xa nudc thai chua xii' ly ciia nha may dudng ciing ed the la nguyen nhan gay hien tugng chdt tdm mgt sd ao nudi va da bj ngd nhan la viee dao bdi nen day de bat eon Gia Bien, Mdng Tay Vdi phan cua tram tfch dugc trinh bay d tren, viec dao bdi nen day dam Thiiy Trieu de khai thac eon Gia Bien, Mdng Tay khd cd the gay eac tai bien mdi trudng nhu gay chet cac vat nudi dam Bang 7: Chat lugng mdi trudng dam Thiiy Trieu thai ky 2002-2003 (Pham Van Tham et al, 2006) a IVIdi trudng nudc Gia pH (mg/l) (mgA) (mgA) (ng/i) tri 4/2002 VatLL DO COD NO2-N NO3-N NH3,4-N PO4-P Si03-Si Nhe (ng/i) (fig/l) (Mg/0 (Mg/l) Phe (Mg/l) (Mg/I) TB 8.04 36.8 6.21 13.3 4.2 40.3 11.3 2.9 471 569 41.4 CT 7.95 25.3 4.94 11.6 2.4 35.0 1.0 207 458 34 CD 8.17 11 57.0 11 6.85 11 17.9 11 8.8 11 45.0 11 40 11 5.0 11 952 11 817 11 51.3 11 10/2003 TB 7.72 31.9 6.17 10.9 7.6 64 196 17.4 215 593 35.5 CT 7.28 21.0 4.84 8.5 6.0 56 34 7.8 151 512 30.3 CD 8.16 11 40 11 6.56 11 12.6 11 9.3 11 70 11 296 11 26.8 11 317 11 649 11 41.0 n n b Mdi trudng tram tich Gia tri TB CT CD n Che (%) Nhe Pts (fi^/s) (fi^/g) Thang 4/2002 0.72 623 470.1 2.33 1201 951.6 0.11 199 34.7 11 11 11 Che (%) 0.62 1.04 0.1 11 Nhe Pts (M^/S) (Mg'^g) Tlbang 10/2003 371.7 304.4 684.5 578.9 118.4 69.1 11 11 TB: trung binh; CT: Cue tieu; CD: Cue dgi, n; sd mdu 42 11 Trong thdi gian gin day, viee xay dung va dua vao boat ddng he thdng xu ly nudc thai cua nha may duang (nam 2004) da lam cai thien phin nao chit lugng nudc a vuc nudc lan can mac dii vin edn tinh trang ham lugng ammonia kha cao nhu da neu tren Ket qua giam sat moi trudng eiia Sd Tai nguyen Mdi trudng tu nam 2000 ddn da khang dinh dieu Tuy nhien, chit lugng nude dim khdng nhung bj anh hudng tii' hoat dgng cua nha may duong ma cdn bj anh hudng bdi cac ngudn thai khac nhu la nudi trdng thuy san, sinh boat IV NHAN XET Til' cac ket qua trinh bay tren day cd the dua mgt sd nhan xet ve chat lugng mdi trudng dam Thiiy Trieu nhu sau: Chat lugng mdi trudng nude edn kha tdt, ham lugng cac mudi dinh duong nitrate va phosphate cd liie vugt qua GHCP nhung khdng dang ke, mdt sd gia tri cua ammonia ciing hai cao so vdi GHCP nhung khdng nhieu Gia trj ciia COD hoi cao nhung ham lugng oxi hda tan d miie khdng thap Ham lugng eac chat hiiu ca tram tfch chi d miic trung binh Ti sd moi C/N kha ldn chiing td ngudn gde luc nguyen ciia cac chat huu cc Phan dudi sau ciia cac cdt tram tich (cot miu dai nhit la 36 em) cQng khdng chiia nhieu yeu td gay nhiem ban (N va P) Nhin chung, chat lugng mdi trudng nude vao miia khd (4/2006) tuang ddi tdt ban so vdi miia mua (10/2005) dd mdi trudng tram tfch hau nhu khdng cd sir khac biet Chat lugng mdi trudng dam Thiiy Trieu hau nhu khdng cd sir thay ddi Idn so vdi cae nam 1995 va 2002-2003 Tuy nhien so vdi nam 2002-2003 thay rang cd su giam dang ke ham lugng cua ammonia vao miia mua Ldi cam on: Tac gia chan cam an ThS Dd Huu Hoang (ehii nhiem de tai "Nghien cii'u ngudn Igi va eae giai phap khai thae hgp ly loai Mdng Tay va loai Gia Bien tai dam Thiiy Trieu - Cam Ranh" ) da tao dieu kien thuan Igi sii' dung sd lieu de hoan bai bao 43 TAI LIEU THAM KHAO APHA, 1995: Standard Methods for Analysis of Water and Waste Water FAO, 1975: Manual of Methods in Aquatic Environment Research - Part 1: Methods for Detecting, Measurement and Monitoring of Water Pollution Fisheries Technical Paper N° 137 Bui Hdng Long va Pham Van Chung, 2006 Bao cao chuyen de "Vd dac didm thuy van va dgng lire hgc vinh Cam Ranh" 70 trang Pham Van Tham, 1998: Mdt sd dac didm hda mdi trudng vinh Cam Ranh Tuyen tap nghien ciiu bien Tap Vlll Trang 54-66 Pham Van Tho'm, 2003: Bao eao "Hien trang mdi trudng nudi thuy san tinh Khanh Hda" 22 trang Sd" Thiiy san Khanh Hda, 2006 Bao cao "Tinh hinh nudi trdng thuy san va qui hoach phat trien nudi trdng thuy san dam Thiiy Trieu - vjnh Cam Ranh " 18 trang Pham Van Thom, Le Thj Vinh, Nguyen Hdng Thu, Duang Trong Kiem, Pham Hu'u Tam, 2006: Danh gia anh hudng ciia cac hoat dgng cdng nghiep va nudi trdng thiiy san ddi vdi chat lugng mdi trudng dam Thiiy Trieu - Tap chf Khoa hgc Cdng nghe Bien Trang 66-77 Tai lieu luu trii' tai phdng Tai Nguyen va Moi Trudng tinh Khanh Hoa va tai phdng Thiiy Dja Hda - Vien Hai duong hoc Nha Trang 44 ENVIRONMENTAL QUALITY OF THUY TRIEU LAGOON, KHANH HOA PROVINCE LETHI VINH Summary: Results of Investigations in 2005-2006 indicated that water quality of Thuy Trieu Lagoon was relatively good although concentrations of ammonia, nitrate, and phosphate were sometimes higher than the maximum allowable value regard to waters for marlculture (70 pg/l for NH3J-N; 100 jug/l for NO3-N; 15 fig/l for PO4-P) and DO concentration was rarely below the minimum value of mg/l The values of parameters were ranged from 22.2 to 45.2 mg/l for total suspended solids; 4.8 - 7.40 mg/l for DO; 15.3 - 37.3 mg/l for COD; 0.3 - 5.0 ngNA for NO,; 44 - 155 figNA for NO3; - 84 pgNAfor NHij; 3.6 25.6 pgPA for PO4; 232 - 1464 figSlA for SIO3; 436 - 786 figNA for organic N; 27.5 - 44.5 pgP/lfor organic P For sediment quality, content of organic matters was not high (organic Carbon from O.I to 1.3 %; organic Nfrom 70 to 1294 pg/g and total P from 16.3 to 716 fig/g), they were mainly terrigenous in origin Environmental quality of Thuy Trieu Lagoon did not show big difference compared to studied results In the 2002-2003 period except for high concentration of ammonia In October, 2003 (maximum: 296 figN/l) Ngdy nhdn bdi: 21 - - 2008 Diaclti: Vien Hai duong hgc Ngudi nlian xet: Ths Hoang Tmng Du 45