6i txidng n g h i e n cufu
L. Nguon nxidc song To Lich: Song To Lich diidc b&t nguon tu" Ho Tay chay doc
anh p h o ' t h e o B^c - N a m . Tru:6c khi do vao song Nhue d Km 14 (Thanh Liet) liiu ng To Lich c6 dien tich k h o a n g 7750 ha, liiu liidng t r u n g binh 5m^/s, theo thong 1 nay nifdc t h a i sinh hoat tai Ha Noi khoang 300 - 400 ngan m^/ngaỵ Song To lidc xem nhii la cong t h o a t midc t h a i chfnh ciia t h a n h phọ Doan song To Lich
khu viic Linh Dam - Dai Kim chu yeu la midc thai sinh boat ciia dan cU xung
vdi mile do 6 nhiem Ictn.
:. Cac loai thiic vat thf nghiem.
Cay r a u muong núdc (Ipomoea aquatica): La loai song troi noi t r e n m a t núdc,
d p , n h a t d n h i e t do 25-30°C. Re moc tii cac dot dúdc tiep xuc v6i dat am hoac vdi
La r a u h i n h Iiidi mac dai k h o a n g 10-15 cm, cay co t h e trong tit h a t hoac tit mot
cua t h a n , r a ngon n h a n h k h o a n g 2 t h a n g co t h e t a n g gap doi sinh khoị Rau ig CO sufc song m a n h liet trong moi triidng 6 n h i e m nang, k h a n a n g h a p t h u cac tv^ moi trifdng r a t m a n h , ke ca cac c h a t kim loai n a n g . Rau muong p h a t trien 1 n h a t d he r i chum, qua t r i n h h a p t h u cac c h a t cung dien r a d day nhd ban t h a n vat va vi sinh v a t b a m dfnh.
- Cay ngo (Enydra fluctuans): Cay t h a o song noi hay ngap nxidc, p h a n eanh nhieu,
t. Ngo CO the p h a t trien m a n h t r o n g niidc ban, ehiu diidc khf h a u da dang, nhiet do (ha n a n g l a m sach niidc r a t tot dac biet la khii miii hoị Kinh nghiem dan gian cho
b dau CO ngo la cl do nifdc t r o n g va k h o n g co m u i hoi thoị
- Cay say ( P h r a g m i t e s communis): Co t h e song d kh^p ndi dac biet la khf hau
am, nhiet do moi trifdng toi \iu la 12-30°C. Nong do muoi toi da co the ehiu diing la 45 %ọ Say co t h e song trong miic niidc tit 30 cm den 150 cm va trong khoang
-8. He re cua say p h a t t r i e n r a t n h a n h , bam ch&c vao dat. Khong nhii cac cay khac ihan oxy k h o n g khf qua khe hd cua d a t va re, cay say co cd cau van ehuyen oxy d
rong tii t r e n ngon cho tdi t a n re do vay say c6 the ehiu dU6c dieu kien khac nghiet,
) van ehuyen oxy tii khong khi xuóng he re va vung re r a t n h a n h 5-12g/m^.ngay p. Dresser a n d Mckes,1977; SCS Engineers, 1980) tao moi trirdng hieu khf cho re, diidc vi sinh v a t sii dung cho qua t r i n h p h a n buy hoa hoc. lidc tinh so liidng vi 1 trong d a t q u a n h re cay say co the nhieu nhii só vi k h u a n trong be hieu khi ky
dong thdi p h o n g p h u ve ehung loai tii 10-100 lan. Chfnh vi vay eanh dong lau say ! xii ly diidc nhieu loai niidc thai co chat doc hai khac n h a u va nong do 6 nhiem Idn alf& Eđy, Inc. 1991).
^hifofng p h a p n g h i e n ciiu
Thu t h a p só lieu thii cap: tii cac nghien ciiu triidc daỵ Tim tai heu tii m a n g Let.
Cac phiidng p h a p p h a n tfch chi tieu hoa, lỵ
Cac chi tieu diidc liia chon de p h a n tfch chat liidng niidc la: pH, can Id liing, COD, NO3, NH4, PO4. Cac phiidng p h a p p h a n tfch diidc t u a n theo cac tieu c h u a n va qui lien h a n h eua Bo Tai nguyen va Moi triidng.
ke mo h i n h thf nghiem.
Mo h i n h thf nghiem trong thiic v a t diidc thiet ke tiidng tii nhii m a n g dan nUdc. hirdc moi thiing la 0,7m x 0,7m x 1,5m.
+ Thung 2 trong ngo d a i , phfa dif6i day co 16p cat day 15 cm nham co dinh he r l la ndi cif trii cua vi sinh vat.
+ Thung 3 tr6ng say, mat do cay khoang 20 cay/m^. Day thiing co 16p soi nhSm co ih he re, tang dien tfch tiep xuc vdi vi sinh vat.
Trong lifdng cua ttfng loai cay khoang 5 kg Thiet ke thf nghiem.
Cac thung dacJc phan each nhxi cac he thong rieng biet. Nifdc song di^dc do triic
D vao cac thung chiia thilc vat. D^u tien.cac loai thiic vat difdc trong trong 1 tu^n cho -n v6i dieu kien song mdị Ket qua trvfc quan cho thay sau 3 ngay cac loai thiJc vat thich nghi vdi dieu kien mdi: than, la tiidi, sau 7 ngay da ra ngon hay dam choi mdị
ti hanh thay nifdc song mdi vao, bat d I u qua trinh xii lỵ Tinh tit ngay lifu niidc thii
ach 2 ngay l^i lay m l u niidc trong cac thiing khac nhau phan tfch 1 lan, tien hanh
miu 6 lan (tong cong thdi gian Ivfu nxidc la 12 ngay).