Tiiu ban: Moi truang vd Ndng luang ISBN: 978-604-913-013-7
CONG NGHE SINH THAI Slf DUNG THU^C VAT THUY SINH TRONG Xir LY N\Sbc PHU DU^OHVG
Tran Van Tua, Nguyen Trung Kien, D6 Tudn Anh, Vu Thj Nguyet, Hoang Trung Kien, Le Thi Thu Thuy, Dang Dinh Kim, Le Dire Vien Cong nghe Moi tru6ng; 18 - Hoang Quoc Viet, Cau Giay, Ha Noi
Email: tranvantua (^gmail.com Tom tat:
Su phii duang (eutrophication) cdc thuy vice nude ngot ngay cdng gia tdng do su thdm nhap cdc chdt him ca, N vd P tic sinh hogt vd hogt ddng sdn xudt ciia con ngudi. Su phii duong ddn den "nd hoa nude " do vi tdo bao gdm vi khudn lam ddc phdt trien mgnh, Idm mdt cdn bdng sinh thdi vd suy gidm chdt luang nude. Trong
xic ly nude phii duong nhdt Id vdi cdc thuy vuc lan, cdng nghe sinh thdi sic dung thuc vdt thuy sinh (TVTS) cd nhieu uu diem vd rdt thdn thien mdi truang. Chiing tdi trinh bdy dual day ket qud nghien cim xie ly nuac ao hd phu dudng sic dung he thdng TVTS nhu Ngd trdu, Rau mudng, Beo tdy vd Cdi soong a qui md pildt. He thdng xie ly la cdc muong ddi ndng trdng cdy cho nude chdy qua. So vdi ddi chieng, hieu sudt xie ly TN tdng tie 2,10 den 3,19 ldn. Vai cdc chi sd: TSS, TP, COD vd Chl.a, hieu sudt tdng tieang icng Id 2.85-3,32; 1,87-2,14; 2,03-4,88 vd 2,54 -2.89 ldn. Khi he thdng hogt ddng lien tuc, hieu sudt logi bd Chl.a, TSS, TN, TP, COD tuang icng Id 64-91%, 53-83%. 20-32%. 42-67%, 49-64% . Nude ddu ra cd luang Tcoliform gidm 6-10 ldn vd dgt mice Al ve chdt luang nude mat theo QCVN08-2008/BTNMT cita Bd Tdi nguyen vd Mdi truang. Ddn lieu tren day Id khd quan cho viec md rdng thuc nghiem hien truang nhdm icng dung he thdng TVTS trong xir ly nude ao hd phii dudng trong dieu kien nude ta.
Abstract:
The eutrophication of the fresh waterbodies is due to the increasing content of organic matter, N and P orgirinated from human activities. The eutrophication leads to the "water bloom" caused by powerful growth of microalgae, including toxic cyanobacteria, the ecological imbalance and declining water quality. Ln eutrophie water treatment, especially with large waterbodies, the ecological technology using aquatic plants has many advantages and is environmentally friendly. We present in this report the results of the research on eutrophie water
treatment by aquatic plant systems in pilot-scale. Treatment systems are the shallow long trenches planted with aquatic plants such as Enydra fiuduans, Ipomoea aquatica, Eichhornia erassipes and Rorippa nasturtium aquaticum.
Compared with control, TN treatment efficiency increased from 2.10 to 3.19 times while these values of TSS, TP, COD and Chl.a were 2.85-3.32, 1.87-2.14, 2.03- 4.88 and 2.5 -2, 89 times, respectively. When the system operates continuously, the efficiency of Chl.a, TSS TN, TP, COD removal was 64-91%, 53-83%, 20- 32%, 42-67%, 49-64%, respectively. The Total coliforms of the output water reduced 6-10 times and md Al level of QCVN08-2008/BTNMT concerning surface water quality. The obtained results are good scientific basis for enlarging the system applied in eutrophie water treatment in Vietnam.
Hoi nghi Khoa hoc ky niem 35 ndm I'ien Khoa hoc vd Cong nghe Viet Nam - Hd Noi 10/2010
1. MO DAU
Sir tham nhap cac chat hiiTi co. N va P tir nuoc thai sinh hoat va boat dgng san xuat ciia con nguoi la nguyen nhan gay phu duong cac thuy vuc nuoc nggt. Phii duong dan den "no hoa nuoc" do vi tao bao gom vi khuan lam (VKL) dgc phat trien manh, lam mat can bang sinh thai va suy giam chat lugng nuac [2,6]. Trong xu ly nuoc phii duong nhdt la voi cac thuy vuc Ion, cong nghe sinh thai (CNST) noi chung va CNST sir dung thuc vat thuy sinh (TVTS) co nhieu uu diem, rat than thien moi truong, duoc cac nha nghien cim nhieu nuoc rat quan tam [ 3 , 4 , 5 , 1 0 ] .
Nguon nuoc mat noi dia ciia Viet Nam nhat la cac ho va ho chira dang bi phii duong ngay cang gia tang kem theo do la sir bimg phat vi tao trong do co VKL dgc da dugc phat hien nhu loai Microcystis aeruginosa [1]. Mot so nghien cim sir dung CNST vol TVTS nhu beo tay, beo cai, say... .trong xir ly nuoc thai 6 nhiem hihi co a Viet Nam da dugc tien hanh va co ket qua kha quan [8, 9]. Tuy nhien, irng dung CNST sir dung TVTS trong xir ly nuoc phu duong, bao ton he sinh thai ho c6n rat han che. Chiing toi trinh bay duoi day ket qua nghien cim 6 qui mo pilot ve kha nang loai b6 mot so yeu to phu duong moi tru6ng nuac ciia mot so TVTS dien hinh ciia Viet Nam. Nghien cim dugc thuc hien trong khuon kho de tai dgc lap cap nha nuoc ma s i DTDL.2009T/08.
2. DOI TU^O>4G VA PHU^OTVG PHAP 2.1 Doi tuong nghien ciiu:
Nuoc phu duong sir dung cho nghien cim nay la nuac ho khu thuc nghiem Co Nhue, Vien KH&CN Viet Nam. TVTS sir dung cho nghien cuu la Beo tay {Eichhornia crassipes)-Wl, Ngo trau {Enydra fluctuans)-NT, Rau muong {Ipomoea aquatica)-RM xa Cai soong {Rorippa nasturtium aquaticum)-CS. Cac cay non, kh6e dugc dua vao he thong xir ly.
2.2 Phu-oTig phap su dung:
Phan tich cac chi tieu chat lugng nuoc nhu TN, TP, TSS, COD va Chlorophin a (Chi a) theo cac phuong phap chuan [7]. He thong xir ly pilot (binh 1) gom 4 muong song song co kich thuoc dai, rgng, sau tuong irng la 4,6m. 0,8ni, 0.2m. Moi muong trong mot loai cay neu tren va mirc nuoc trong cac muong la 10cm. Niioc phii duong tir bo dugc bom len be chua va phan phoi deu qua cac muong. He thong hoat dgng lien tuc. Hang tuan lay mau danh gia cac chi so phii duong truoc va sau xir ly. Lugng coliform xac dinh theo phuang phap nhieu ong.
Dem mat do te bao vi tao trong buong dem Lagoette (Germany) va tinh theo cong thirc sau:
Mat do = [A/(30xl,25) x V)] trong do: A la tong so te bao co trong 30 6. 30 la so lugng 6 dem. 1,25 la the tich ciia 1 6 ((al) va V la the tich mau ban dau (|il).
Hinh 1: Thuc nghiem xic ly nude ao hd phii dudng bdng
TVTS qui md pildt
Tieu ban: Moi truang vd Ndng luang ISBN: 978-604-913-013-7
Cac thiit bi sir dung trong phan tich: May quang phi UV-2400 (Shimadzu, Nhat Ban), COD Reactor (HACH, My), can phan tich Sartorius (CHLB Dire), kinh hiln vi Olympus BX51 (Nhat Ban).
3. KET QUA NGHIEN CUtJ VA THAO LUAN 3.1 Vai tro cua TVTS trong loai bo yeu to phii duong
Thuc nghiem qui mo pillt so sanh hieu qua loai bo cac yeu to nhu TN, TP, TSS, COD, Chi a ciia he thing TVTS voi DC khong c6 cay lam sang t6 vai tro ciia TVTS trong loai b6 cac ylu tl nay. Khi nIng do TN, TP. Chi a, TSS va COD trong mot lit nuac ddu vao la 2,263 mg/1; 0,298mg; 140,508^g; 0,093g; va 44,593mg, kit qua trinh bay a hinh 2 cho thdy, hieu sudt loai b6 TN boi BT, RM, NT va DC tuong img la 35,57%; 27,13%; 23,60% va 11,22% . Nhu vay, cac muong c6 cay da loai bo TN tang tir 2,10 din 3,19 ldn so voi DC. Nhan xet tuong tu cung thdy voi cac chi si nghien ciiu khac nhu TSS, TP, COD va Chl.a, hieu suat loai b6 tang tuong img la 2,85-3,32; 1,87-2,14; 2,03-4,88 va 2,54 -2,89 ldn.
LTinh 2: Vai trd ciia TVTS trong logi bd yeu td phii dudng
3.2 Hieu suat xu ly yeu to phii duong o cac tai luong nu-dc khac nhau
D I danh gia hieu suat loai bo cac nhan to phu duong, tac gia cho he thong boat dgng lien tuc 5 tudn voi tai lugng 100 1/m^/ng, va 6 tuan voi tai lugng 200 1/m^/ng. Do khuon kho ciia bai bao, chiing toi khong the trinh bay chi tiet ket qua phan tich hang tuan a moi tai lugng va timg loai cay ma chi dan ra day so lieu cuoi ciing cho moi tai lugng. Ket qua phan tich ham lugng cac yeu to phu duong ciia nuoc truoc va sau xir ly trinh bay o bang 1. Voi ham lugng TP va Chi a trong nuoc dau vao la 0,328-0,432 mg/1 va 169,1 - 262,995(ag/l, nuac ho dua vao xir ly dang a tinh trang phii duong rat cao.
Bdng 1: Tdng hap hieu sudt xic ly ciia he thdng cdy thuy sinh qui md pildt Tdi luang
(l/m2/ngdy) 100
Chi sd
Chla(|ig/1) H%
TSS (g/1) H%
TP (mg/1)
Ddu vdo
169,100
0,054
0,328
Ddu ra-Muang TVTS BT
31,328 81,47 0,010 81,48 0,140
NT 47,3035
72,03 0,014 74,29 0,190
RM 59,4128
64,87 0,018 65,89 0,209
CS 56,9455
66,32
0,022
58,41
0,214
Hoi nghi Khoa hoc ky niem 35 ndm Vien Khoa hoc vd Cong nghe Viet Nam - Hd Noi 10/2010
200
H%
COD(mg/l) H%
TN (mg/1) H%
Chia (Mg/1) H%
TSS (g/1) H%
TP(mg/l) H%
COD(mg/l) H%
TN(mg/l) H%
48,622
2,432
262,995
0,071
0,432
67,856
3,820
57,32 16,025
67,04 1,692 30,43 21,583
91,79 0,012 83,09 0,141 67,36 24,103
64,48 2,573 32,64
42,07 24,327
49,97 1,924 20,89 53,248
79,75 0,014 79,48 0,209 51,62
"30,951 54,39 2,923 23,48
36,28 23,984 50,677 1,814 25,41 78,563
70,12 0,033 53,26 0,244 43,52 31,117
54,14 2,891 24,32
43,76 20,28 57,16 1,903 21,75 56,302
78,59 0,016 77,09 0,211 51,15 29,583
56,40 2,912 25,08 Khi boat dgng voi tai lugng 100 lit/m2/ng., hieu sudt loai bo Chi a, TN, TP, TSS va COD ciia muong boi BT la 81,47%; 30,43%; 57,32%; 81,48% va 67,04%, tuong img. Hieu sudt nay la cao nhat trong 4 loai TVTS nghien ciiu. Trong 3 muong c6n lai, NT loai Chi a va TSS kha ban nhung COD, TN va TP khong hon RM va CS. Nhin chung 3 cay c6n lai loai tir 64,87% (RM) din 72,03% (NT) Chi a; 58,42% (CS) din 74,27%(NT) TSS; 36,26%(RM) din 43,76%(CS) TP; 49,97%(NT) din 57,16%(CS) COD va 20,89%(NT) den 25,41%(RM) TN.
CJ tai lugng 200 l/m2/ng., phan Ion bieu suat xir ly cac chi so phan tich deu cao hon (tuy khong nliilu) so voi tai lugng 100 l/m2/ng trong khi nong do dau vao ciing cao hon. Thi du nhu voi BT, nIng do TN tir 2,432 mg/1 o luu lugng 100 tang len 2,820 mg/1 a luu lugng 200, hieu sudt xir ly tang tir 30,43% len 32,64%. Su so sanh nay ciing khong that logic vi thai diem hoat dgng ciing nhu nhilu yeu to khac cua moi truong la khong nhu nhau. Mat khac, theo ly thuylt vl lgc, co mot dilm dimg (break point) trong tuong quan giira tai lugng va chat lugng nuoc. Truoc dilm nay, tac dgng ciia tai lugng len hieu qua loai bo (%) khong ro rang [5]. Do tang tai lugng, khIi lugng vat chat loai b6 tren don vi dien tich boat dgng ciia he thong se cao ban. Tinh toan xa'i truang hgp BT, khoi lugng TN, TP, TSS, Chi a va COD loai bo moi ngay tren lm2 o tai lugng 100 l/m2/ng. la 74,0Img; 18,8 mg; 4,4g; 13,76 mg va 3,13g, tuong ung.
Voi tai lugng 200 l/m2/ng., cac si lieu thu dugc la: 124,68mg; 29,Img; 8,37g; 24,14 mg va
4,38g. Nhin ting thi hieu qua cao nhat van thuoc ve muong BT. Trong ba muong c6n lai, uu
thi khong thuoc vl cay nao vi co the cao o chi so nay nhung lai thap a chi so khac.
Tieu ban: Mot tru&ng vd -^dng luang ISBN: 978-604-913-013-
3. Hieu qua xir ly vi tao va vi khuan lam (AKL) cua he TVTS
Hau qua ciia phii duang la su bimg phat xi tao xa \'KL. He thong muong TVTS khong chi loai bo hieu qua cac xku t l nhu TN. TP... ma c6n loai bo kha tit xi tao xa VKL. So lieu a bang 2 chiing minh nhan xet nay. Vai mat do tl bao xi tao rat cao trong nuoc dau \ao. BT loai dugc 79.33% \ i tao tong s i xa 82,80% VKL. Cac muong c6n lai. hieu sudt co kem BT nhung ciing cho con si rdt y nghia\-a dao dgng tir 49.83-65.25% ting s i xi tao va 52.37-62.80% VKL. 0 muong DC. chi CO 12.68% vi tao \ a 10.2% VKL bi loai. Dang chii y la trong tlianh phan VKL dau \ao c6 tam loai thi hai loai co tilm nang ga>- dgc la Microcystis aeruginosa xa Cylindrospermopsis raciborskii. Loai M aeruginasa la loai xudt hien a hau het cac thu>- MJC nuac nggt phu duang.
Loai nay san sinh dgc to gan microcystin \ oi dgc tinh rat cao. To chiic y te The giod da qui dinh.
nong do dgc to cua tao dgc trong nuac uong cho con nguod khong \Tjgt qua 1 ugT.
Bang 2: Hieu qua logi bo vi tao vd VKL (Trieu te bdo lit: Ttb I)
Chi sd
Vi tao ting si (Ttb/1)
% loai bo
VKL tong (Ttb/1)
% loai bo
Ddu vdo
1592.373
96.123
Ddu ra - Muang TJ TS BT
329.189 79.33 16.533
82.80
AT RM ' CS 798.861
49.832 41.045 57.30
674.138 : 553.349 57.66 65.25 35.733
62.80
45.783 52.37
DC 1390.332
12.68 86.318
10.20
Xac dinli lugng Coliform \'a thay rang: voi 7000 MPN/100 ml trong nuoc dau vao tuong duong mirc Bl cua QCVN08:2008/BTNMT va chua the dimg cap nuoc sinh hoat. Sau khi qua muong BT. NT. RM va CS. lugng coliform con lai tuong ling la 680. 200. 680. va 1100 MPN/100 ml. Lugng coliform nay thap hon qui dinh tai mirc Al cua qui chuan neu tren \'a la mirc sir dung tot cho cap nuoc sinh boat.4. KET LU.4N
Tir cac ket qua nghien ciiu nhan dugc. chiing toi nit ra mot so nhan xet sau: '' - Cong nghe sinh thai sir dung he thong TVTS nhu Ngo Trau. Beo Ta\-. Rau Mulng va
Cai Soong khong chi loai bo hieu qua cac yeu to gay phu duong moi truang nuoc nhu TN. TP, Chi a. TSS. COD ma c6n ca vi tao va VKL doc. Nuac sau xu Iv dat mirc Al ciia Q C V N 0 8 : 2 0 0 8 / B T T N M T vl coliform.
- Trong 4 loai TVTS su dung. Beo Tay cho hieu qua xir ly cao nhdt. Ba cay c6n lai la Ngo Trau, Rau Muong va Cai Soong tm' hieu qua c6 kem ban nhung van kha hieu qua.
Ve gia tri sir dung thi 3 loai cay nay ban beo tay a cho co thi sir dung lam thirc an cho chan nuoi va lam rau xanh trong truong hgp ciia Rau Mulng va Cai Soong.
- Cong nghe xir ly nuac phu duong tren la dan gian. co chi phi thdp. dl van hanh va quan ly. Ket qua thu dugc buac dau a qui mo pillt rdt kha quan. Tuy nhien. dl img dung he thong trong xu ly nuoc ho phu duong tren qui mo Ion cdn tilp tuc ma rgng qui mo^hu nghiem he thong nay ngoai hien tmong \'ai cac thong s i da dang ban. thai gian dai ban.
Hoi nghi Khoa hoc ky niem 35 ndm Vien Khoa hoc vd Cong nghe Viet Nam - Hd Noi 10/2010
LOfI CAM ON
Day la mot phan trong nhiing ket qua nghien cim ciia De tai dgc lap cdp Nha nuoc ma s i DTDL.2009T/08. Cac tac gia xin cam on Bg Khoa hgc va Cong nghe, Vien KH&CN Viet Nam da cho phep thuc hien nghien ciiu nay.
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3. Miao Li, Yue-Jin Wu, Zeng-liang Yu, guo-Ping Sheng, Han-Qing Yu, "Nitrogen removal from eutrophie M'ater by fioating-bed-grown water spinach (Ipomoea aquatica Forsk.)
with ion implantation". Water research, 41(2007): 3152-3158
4. Linfeng Li, Yinghao Li, Dilip Kumar Biswas, Yuegang Nian, gaoming jiang, "Potential of constructed wetlands in treating the eutrophie water: Evidence from taihu lake of China", Bioresourse Technology 99(2008): 1656-1663
5. Xian-Ning Li, Hai-Liang Song, Xi-Wu Lu, Xiang-Feng Xie and Yuliei Inamori.
"Characteristics and mechanisms of the hydroponic bio-filter method for purification of eutrophie surface water". Ecological Engineering. Vol. 35, Issue 11. 2009: 1569-1573.
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"Nghien dm khd ndng xie ly nude thdi che bien thuy sdn cua cdy beo Tdy ", Bao cao Khoa hgc tai Hgi nghi toan quoc 2005: NCCB trong khoa hgc su song, Dai hgc Y Ha Noi, 3/11/2005, Nha XB KH& KT, tr. 827-830.
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