Chất lượng môi trường nước đầm nha phu vịnh bình cang và mối liên quan với các hoạt động kinh tế

Tuyin Tap Nghien Ciru Biin, 2010, XVII: 53-63
CHAT LUONG MOI TRl/OTVG NlTOG DAM NHA PHU - VINH BINH CANG
VA MOI LIEN QUAN v O l CAC HOAT D0NG KINH TE

Pham Huu Tam, Le Thi Vinh, Duong Trong Kiem, Nguyen Hong Thu, Pham Hong Ngo
Vien Hdi duong hoc
Tom tat Ket qua nghien cuu cho thay, vai thong so trong moi truong nuoc tai khu
vuc dam Nha Phu (chu yeu d vung dinh dam) co gia tri nam ngoai gia tri gidi
han (GTGH) ciia tieu chuan nude nuoi trong thiiy san Viet Nam, 5943: 1995
va ciia cac nude Asean, the hien rat ro vao miia mua: oxy hoa tan (4,75mg/l).
vat lo lirng (83,3mg/l), nitrate (71 u.g/1), ammonia (73ug/l), ham luong
hydrocarbon trong nude d tat ca cac tram khao sat deu vuot GTGH. Chat
luong moi trudng khu vuc vinh Binh Cang it 6 nhiem hon so vdi khu vuc
dam Nha Phu, hau het cac thong so trong moi trudng nude d vinh Binh Cang
deu nam trong GTGH, chi co ham luong hydrocarbon vuot GTGH (he so 6
nhiem la 2,14 vao miia kho va 1,64 vao miia mua).
Ket qua phan tich cac mau nude thai cho thay nhieu thong so moi trudng cd
gia tri nam ngoai GTGH duoc quy dinh trong TCVN 6772: 2000 (muc 1):
ham luong ciia BOD (Tan Thiiy 1: 69,7mg/l; Tan Thiiy 2: 38,2mg/l), N0 -N
(Tan Thiiy 3: 57.893ug), TSS (Tan Thiiy 2: 2.970,8mg/l). Dac biet ham
luong coliform vuot GTGH nhieu lan (he sd d nhiem: 24 x 10 - 75 x 10 ).
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ENVIRONMENTAL QUALITY OF NHA PHU LAGOON - BINH CANG BAY
WITH RELATION TO THE ECONOMIC ACTIVITIES

Pham Huu Tam. Le Thi Vinh. Duong Trong Kiem, Nguyen Hong Thu, Pham Hong Ngo
Institute of Oceanography
Abstract The studied results show that concentration of environmental parameters in
Nha Phu lagoon (such as dissolved oxygen, total suspended solids, nitrate,
ammonia) exceeds the limit values, expressed very clearly in the rainy
season, hydrocarbon content in water at all stations is over the limit values.
Environmental quality in Binh Cang bay is better than Nha Phu lagoon, most
of the parameters of the water environment in Binh Cang bay are in the limit
values, only the hydrocarbon content exceeds the limit values.
The analysis of wastewater samples shows that the concentration of
environmental parameters such as BOD , NO3-N, TSS exceeds the limit
values. Specially, concentration of coliform exceeds the limit values several
times (with pollution coefficients: 24 x 10 - 75 x 10 ).
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I. GIOI THIEU

5

Viing dinh dam Nha Phu cd mot sd song
sudi dd vao, tren luu vuc cac song nay hoat
ddng san xuat ndng nghiep va nuoi trong
thiiy san dien ra kha sdi ddng. Tir nam
1995 den nam 2007 gia tri san xuat ndng
nghiep toan huyen lien tuc tang: Nam 1995
dat khoang 255,4 ty ddng, nam 2000 dat

Dam Nha Phu - vinh Binh Cang la
vinh bien nua kin ven bd Mien Trung, nam
each thanh phd Nha Trang 20km ve phia
bac. cd vi tri dia ly tir 109°09' - 109°17'
kinh do ddng va 12°18'-12°27' vT do bac.
53


275 ty ddng va den nam 2006 tang nhanh
den 346 ty dong. San luong thuy san nuoi
trdng toan huyen trong nam 2007 la 4.618
tan, bang 115,39% so vdi cung ky nam
2006, nang suat torn nuoi binh quan dat
1,09 tin/ha, san lugng torn toan huyen nam
2007 la 2.000 tin, bang 116,41% va tang
282 tin so vdi cirng ky nam 2006 (Phong
Th6ng ke huyen Ninh Hoa, 2007). Nhirng
hoat dong kinh te dien ra trong khu vuc
nghien cuu co kha nang tao ra nhung nguy
co ve suy thoai chat luong mdi trudng, din
den suy giam nguon loi thiiy san, de dga
true tiep cudc song ciia cu din song quanh
dam ddng thoi giy d nhiem cho dim Nha
Phu - vinh Binh Cang.
Trudc diy, nhdm de tai chiing tdi
ciing nhu mot sd tic gii da quan tim
nghien ciiu mdi trudng khu vuc niy, nhu
Bui Hong Long (1996), Le Thi Vinh va cs.
(1996), Pham Van Thom va cs. (1998,
2005), Lai Van Hiing (2004)...thu dugc

mgt sd din lieu tham khao tdt. Tuy nhien,
sau mgt thoi gian tuong ddi dai, mdi
trudng d diy da cd nhieu bien ddi do cac
hoat ddng kinh te va din sinh phit trien,
nen dat vin de nghien ciiu lai mot each
toan dien chit lugng mdi trudng dim Nha
Phu, vinh Binh Cang trong mdi lien quan
vdi cic hoat ddng kinh te la mot vide lam
cin thiet rit cd y nghia khoa hgc va thuc
tien lam co sd khoa hgc phuc vu quan ly,
bio ve mdi trudng, phat trien kinh te ben
vung.

I I . PHlTONG PHAP
1. Thu mau:
+Thuc hien 2 dot khao sat vao thing
5/2008 (mua khd) va thing 10/2008 (miia
mua) dd thu mau nude (Hinh 1). Mau dugc
thu vao luc trieu thap, tdng cdng cd tat ca
40 miu nude da dugc thu.
Cdc chi tieu phan tich bao gdm: V|t
lo lirng, do muoi, DO, BOD , cac mudi
dinh duong (NH , -N, N0 -N, N0 -N,
PO4-P, Si0 -Si), chit huu co (N huu co, P
huu co), coliform, hydrocarbon.
+Thu mau nude ao nuoi torn va nude
thii khu din cu (Hinh 1). Cd 16 mau nude
ao nuoi torn va 6 miu nude thii da dugc
thu va phan tich.
Cic chi tieu phan tich: pH, vat lo

lirng, DO, BOD , mudi dinh dudng (NH , N, NO2-N, N0 -N, P0 -P, Si0 -Si), N huu
co, P huu co), coliform.
2. Phuong phap phan tich:
Cic miu nude duoc xir ly, bio quan
va phin tich theo cic phuong phap tieu
chuan hien hanh (APHA, 2005).
He sd d nhiem duoc tinh theo cdng
thirc:
He sd d nhiem = (Gia tri thuc) : (gia
tri gidi han).
Cac sd lieu lien quan den hoat ddng
kinh te-xa hdi cua vung nghien cuu dugc
thu thap tai phong Ndng nghiep huyen
Ninh Hda.
Xu dung phin mem thdng dung
Microsoft Excel de ve cic do thj.
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Hinh 1. Vi tri cac tram thu mau tai khu vuc nghien ciru
Fig. 1. Location of sampling stations

Chu thich: A: khu vuc ao nuoi xa Ninh Phii,
khuB:
vuc ao nuoi xa Ninh Ha, C: khu vuc ao nuoi xa
Ninh Loc, D: khu vuc ao nuoi xa Ninh Ich
Mot vai thdng sd mdi trudng nude tai khu
III. KET QUA
vuc nay vuot gia tri gidi han (GTGH), ham
1. Hien trang moi truong khu vuc dam
luong dxy hda tan thap hon GTGH duoc
Nha Phu - vjnh Binh Cang:
ghi nhan tai cac tram viing dinh dam
Cac so lieu thu duoc trong 2 chuyen
(4,75mg/l, tram 2), ham luong ciia vat la
khao sat miia kho (thang 5/2008) va miia
limg (83,3mg/l, tram 2), NO3-N (71,1 ug/1,
mua (thang 10/2008) duoc trinh bay d hinh
tram
1 va 3), ammonia (73pg/l, tram 1),

2. 3. Tu cac dan lieu phan tich tren co the
hydrocarbon
(d tat ca cac tram khao sat)
thay ham luong cac yeu to moi trudng cd
cao hon GTGH. Tai vinh Binh Cang, ham
su bien ddi theo khong gian va thai gian rat
luong BOD5 vao miia mua luon thap hon
ro ret. Tai khu vuc dam Nha Phu, dac biet
so vdi miia khd d ca 2 tang nude (tang mat
la viing dinh dam (gdm cac tram 1, 2, 3)
0,64mg/l
so vdi l,09mg/l va tang day
nai tiep giap vdi cac con song, vao mua
0,84mg/l so vdi l,45mg/l). Ham luong ciia
mua gia tri do mudi, ham luong dxy hda
vat la limg, cac mudi dinh dudng (NO2-N,
tan thudng thap han so vdi miia khd (tuong
NH
4-N, PO4-P, Si03-Si) vao miia mua cd
ling vdi cac gia tri trung binh la: 21%o so
pham
vi dao ddng ldn va gia tri cao hon so
vdi 25%o va 5.28mg/l so vdi 6.38mg/l), con
vdi miia khd (cac gia tri trung binh tuong
ham luong vat la limg. cac mudi dinh
img la: 47,48mg/l so vdi 25,18mg/l;
dudng nhu: N0 -N, N0 -N, NH3.4-N,
SiOvSi. P huu ca ldn han so vdi miia khd l,94pg/l so vdi 0,28pg/l; 2pg/l so vdi
lug/1: 5,72 ug/1 so vdi 3,10 ug/1 va461 ug/1
(cac gia tri trung binh tuong ung la:

so
vdi 333ug/l). Tom lai, tai khu vuc dim
31.68mg/l so vdi 70,68mg/l; 6,13ug/l so
Nha
Phu ham luong ciia cac thdng sd mdi
vdi l,52ug/l; 59,83ug/l so vdi 43,83ug/l;
trudng
nude (dxy hda tan, vat la limg.
58,30ug/l so vdi 52,00ug/l: 1.504ug/l so
vdi 934ug/l va 90,78ug/l so vdi 34.77ug/l). NO3-N, ammonia, hydrocarbon) deu nam
ngoai GTGH the hien rat ro vao miia mua.
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55


Trong luc do, d vuc nude vinh Binh Cang
khi so sanh vdi cac tieu chuan chat lugng
nude hien hanh thi con tuong doi tot, phan
ldn cac thong so moi truong nude khao sat

deu nam trong GTGH, ngoai trir ham
lugng ciia hydrocarbon vuot qua GTGH
(he s6 6 nhiem la 2.14 vao miia kho va
1,64 vao miia mua).

DO muoi

1

1

M9/I

n

1

1

DO

Vat lo lung

mg/1

BOD

mg/1
4
3.5
3
25
2
05
0

mg/1

1 1 1
van

N04M
2

NO -N
3

o
3

4

5

2

NH -N

van
3000
2500
2000
1500
1000
500

0

34

2

3

4

3

4

5

Si0 -Si
3

3

4

5

6 9
Tr

m

Chii thich:B (10/08) 0(5/08)
Hinh 2. Bien thien ham lugng ciia mot so thong so moi truong (tang mat) tai khu vuc dam Nha Phu
Fig. 2. The concentration variation of environmental parameters (surface) in Nha Phu lagoon
56


ng/l

P hOu cc (tang m$t)

nl
mg/l

i

2
• (5/08)

3
Vat lo limg
1

n

n

1 Ting mit (5/08)
-ting mSt (10/08)
ng/i

J

N0 -N

5
I (10/08)

ug/1
Hydrocarbon (tang m$t)
700 600 I I

i 11

nl
6

• (5/08)
mg/l

i

i

BOD

t

10
11
I Tang day (5/08)

-Ting day (10/08)

i

l

1

1

] TJng mat (5/08)
-Tang mat (10/08)

I Tang day (5/08)
-Ting day (10/08)

] Tang mat (5/08)
-Tang mat (10/08)

I Tang day (5/08)
-Tang day (10/08)

2

7
8
9
Ting mSt (5/08)
— Tang m|t (10/08)

I Tang day (5/08)
-Tang day (10/08)

Si0 -Si
3

10
11
8
9
Ting day (5/08)
] T3ng mSt(5/08)
I Tang day (5/08)
i 1 Tang mat (5/08)
Ting day (10/08)
-Tang mat (10/08)
-Tang day (10/08)
-•— Ting mat (10/08)
Hinh 3. Bien thien ham luong ciia mot so thong so moi truong tai khu vuc vinh Binh Cang
Fig. 3. The concentration variation of environmental parameters in Binh Cang bay
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T r ? m


2. Moi lien quan cua cac hoat dong kinh
te va dan sinh vdi chat luong moi truong
khu vuc nghien cuu

vugt GTGH, d cdng Tan Thiiy 1 gia tri cua
BOD la 69,7mg/l, cdng Tan Thiiy 2 gia tri
ciia BOD la 38.2mg/l; mudi dinh duong
NO3-N (57.893ug/1, cdng Tan Thuy 3),
Cac hoat dong kinh te, dan sinh da va
ham lugng TSS (2.970,8mg/l, cdng Tan
dang dien ra xung quanh deu xa nude thai
Thiiy 2) va dac biet coliform vuot GTGH
true tiep vao vuc nude khu vuc nghien
rat nhieu lan (vdi he sd d nhiem tir 24 x 10
cuu. Tuy theo thanh phan khac nhau ciia
75 x 10 lan).
tung loai nude thai ma co nhung anh
2.1.2.
Nguon thai tic cdc hoat ddng nudi
hudng nhat dinh den chat luong nude ciia
trong
thuy
san (NTTS):
thiiy vuc nghien ciiu.
Xung
quanh viing nghien ciru la nai
2.1. Dac diem cac nguon thai xung
tap
trung
nghe
nudi torn dia kha phat trien
quanh khu vuc dam Nha Phu - vjnh
cua

cu
dan
4
xa
Ninh Phii, Ninh Ha, Ninh
Binh Cang:
Ldc
va
Ninh
Ich.
Dien tich va san luong
Cac nguon nude thai chu yeu la:
nudi
trong
dugc
the
hien trong bang 3.
nude thai tir cac hoat ddng dan sinh, nuoi
Sd lieu thdng ke thanh phan nude cac
trong thiiy san va nguon nude dd ra tir cac
ao nudi thu dugc tai cac khu vuc nudi torn
song sudi d viing dinh dam Nha Phu.
dia dugc trinh bay d bang 4, 5. Nhung dan
2.1.1. Nguon thai tic hoat dong khu dan cu: lieu d cac bang nay cho thay, do lugng
Xung quanh khu vuc nghien ciiu cd 4 thuc an du thira trong qua trinh nudi tha
xa bao gdm 10 thdn, cac xa Ninh Phu,
torn nen nude trong cac ao nudi cd ham
Ninh Ha cd mat dd dan cu thua that. Con 2
lugng vat la limg, ham lugng nitrate,
xa Ninh Ich va Ninh Loc cd mat do tuong

phosphate, P hifu ca, N hifu ca thudng cao
ddi cao, trong do ndi bat nhat la 2 thdn Tan
hon so vdi nude trong khu vuc dam (cac
Thiiy (Ninh Loc), Tan Thanh (Ninh Ich)
gia tri trung binh tuong img la : 45,2mg/l;
vdi tdng sd dan khoang 8.026 nhan khau,
50,1 ug/1; 4,26ug/l 44,6 Ug/1 va 586ug/l),
trong do cd khoang 20% cu dan d day tap
the hien ro nhat d nhirng ao nudi torn the
trung chii yeu viing gan mep nude ciia dam
chan trang, nhung ao nudi d vao thai diem
vdi dieu kien ve sinh mdi trudng kern va
sap thu hoach.
thai true tiep nude thai vao dam.
2.1.3. Vat chat tie song sudi 0 vung dinh
Dua theo each tinh toan ciia To chirc
dam
Nha Phu:
Y te The Gidi (World Health Organization)
Ket qua phan tich thanh phan nude
vao nam 1993 ap dung cho nhieu quoc gia
tai
dap
Ben Bap (thudc song Dinh) va cau
dang phat trien. khdi luong chat d nhiem
Cay Gang (hop luu ciia 2 con song Nga
do dan cu 2 thdn Tan Thiiy va Tan Thanh
hang ngay dua vao mdi trudng (Bang 1) la Hau va song Nga Da) dugc trinh bay d
bang 6. Cac dan lieu cho thay tat ca cac gia
khong nhd.

trj
va ham lugng cua cac yeu to nhu: mudi
Sd lieu phan tich (Bang 2) cho thay
dinh dudng, chat hiru ca, kim loai nang,
thanh phan nude thai cd chira ham luong
hydrocarbon deu ldn hon rat nhidu so vdi
cao ciia cac chat va vuot xa GTGH dugc
quy djnh trong TCVN 6772: 2000 (miic 1): nude trong dam Nha Phu - vjnh Binh
Cang.
gia tri ciia BODs d cac cdng phan ldn deu
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Bang 1. Ucrc tinh lugng nuac thai do dan cir 2 thon Tan Thiiy, Tan Thanh do vao vung nghien ciiu
Table 1. Estimated amount of wastewater from residential areas flowing into the study area
Chat 6 nhiem
BOD,
Vat la liing
Tong N
Tong P
NH , -N
3 4

Gia trj trung binh khoi lur/ng
(g/ngiroi/ngay)
49,5
107,0
9,0
2,4
3,6

Tai luong chat 6 nhiem
(kg/ngay)
79,2
171,2
14,4
3,8
5,8

Bang 2. Ham lugng cac thong so moi truong ciia nuac thai tai mot so cong thai
tu khu dan cu Tan Thiiy
Table 2. The concentration of environmental parameters of wastewater in
residential area (Tan Thiiy)
Thang 5 - 2008
Thang 7 - 2008
Thong
Don vj
Tan
Tan
Tan
Tan
Tan

Tan
TCVN
Thuy 1 Thuy 2 Thuy 3 Thuy 1 Thiiy 2 Thuy 3
so
(*)
pH
7,5
8,0
7,0
7,65
7,3
8,2
5-9
TSS
mg/l
123,4
119,2
107,8
2714,7 2.970,8 3.413,3
50
BOD
mg/l
20,7
38,2
31.1
69,7
29,9
11,4
30
N0 -N

47,2
60,3
90,3
42,0
26,5
342,0
ug/1
NO3-N
901
898,0 57.893,0 30.000
4024,0 4.851,0 3.111,0
ug/1
NH,. -N
164
104,0
236,0
680,0
780,0
248.0
ug/1
P0 -P
6.000
764,0
2.840,0
6912
3.696,0
1.091,0
2.984,0
Ug/1
N huu co

9.240,0 9.525,0 8.590,0 57790 63.910 146.120,0
ug/i
Phuuco
3.771,0 3.750,0 3.560,0 27520 29.050 50.480,0
ug/1
Coliform MPN/lOOml 61xl0 24x10" 75x10"
1.000
(*): TCVN 6772:2000, (muc 1): dung cho nuoc thai sinh hoat ct khu vuc cdng cong.
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Bang 3. Dien tich va san lugng nuoi trong thiiy san ciia cac xa tai khu vuc nghien ciiu nam
Table 3. Area and aquaculture production of the communes in the study area in 2007
STT
1
2
3
4

Ten xa
Dien tich ao nuoi (ha)
Ninh Phu
320

Ninh Ha
390
Ninh Loc
450
Ninh Ich
460
Tong cong
1.620
(Theo phong Nong nghiep huyen Ninh Hoa, 2007)

59

San luffing (tan)
640
720
1.245
1.557
4.162


Bang 4. Ham lirgng cac thong sd moi truong cua nude ao nuoi torn (thang 5 - 2008)
Table 4. The concentration of environmental parameters of water in shrimp pond (5 - 2008)
a. Cac thong so ca ban va muoi dinh duong
Loai torn Thoi gian Mat do
Vj tri
TSS
BOD, NO -N N0 -N
ao nudi
nudi
tha(ngay) (con/m ) (mg/l) (mg/l)

(ug/1)
(Hg/D
Ninh Ha 1
Su
56
13
3,8
71
118
5.2
Ninh Ha 2
Su
45
100
4.5
3,1
68
Ninh Phu 1
Su
60
15
116
4.0
7.6
68
Ninh Phii 2
Su
105
194
6.4

12,5
285
Chan trang
30
100
208
7,4
3,9
97
Ninh Loc 1
Ninh Loc 2
Sit _
60
10
118
5,4
3,4
94
Ninh Ich 1
Chan trang
582
31,2
11,4
97
Ninh Ich 2
Chan trang
60
110
250
14.9

16,1
97
b. Cac mudi dinh dudng va coliform
Coliform
N he
P he
Vi tri
Thoi gian NH3.4-N PO -P Si0 -Si
(ug/D
tha (ngay) (Ug/1)
(ug/D (Ug/1) (MPN/lOOml)
ao nuoi
(ug/D
Ninh Ha 1
56
37
19.1
286
985
98,2
36
Ninh Ha 2
45
53
10,4
609
950
100,0
930
60

13
12,5
1.050
107,6
36
Ninh Phii 1
Ninh Phii 2
105
268
7,5
427
1.525
255,2
2.400
Ninh Loc 1
30
130
17,2
537
1.125
107,5
0
1 15,5
930
Ninh Loc 2
60
82
7,2
596
1.150

Ninh Ich 1
408
18.4
926
995
96,2
36
Ninh Ich 2
60
144
19,4
481
1.220
108,8
0
z

3

2

3

4

Bang 5. Ham luong cac thdng so mdi trudng ciia nude ao nudi torn (thang 7 - 2008)
Table 5. The concentration of environmental parameters of water in shrimp pond (7 - 2008)
a. Cac thdng sd ca ban va mudi dinh duong
Vj tri
Loai torn

Thoi gian Mat do
TSS
BOD,
N0 -N NO3-N
ao nuoi
nuoi
tha (ngay) (con/m ) (mg/l)
mg/l)
(ug/1)
(Ug/D
Ninh Ha 1
Su
90
20
68,6
2.6
16,0
126
Ninh Ha 2
Sii
105
67,4
6.1
7,6
89
Ninh Phu 1 Chan trang
45
90
264,7
21,0

25,7
228
Ninh Phu 2
Chan trang
60
100
282,7
20,2
21,6
217
Ninh Loc 1 Chan trang
80
222,0
19,5
15,5
138
Ninh Loc 2
Su
120
224,7
12,1
13,5
134
Ninh Ich 1 Chan trang
45
100
336,0
19,5
122
33,5

Ninh Ich 2 Chan trang
100
485,0
19,6
154
20,2
2

2

b. Cac mudi dinh duong
Vi tri
ao nuoi
Ninh Ha 1
Ninh Ha 2
Ninh Phii 1
Ninh Phii 2
Ninh Loc 1
Ninh Loc 2
Ninh Ich 1
Ninh Ich 2

Thoi gian
tha (ngay)
90
105
45
60
80
120

45
-

NH . -N
(ug/1)
308
3
35
228
112
80
66
1 16
3 4

PO -P
4

(ug/1)
294,0
40,0
38,8
65,0
55,0
40,0
92,4
68.8
60

SiOj-Si

(ug/1)
2.320
4.970
4.700
4.930
96
1.022
745
162

N he
(ng/i)
1.252
1.850
1.120
2.250
2.890
1.140
1.850
3.350

P he
(ug/D
140,0
201,2
98,2
340,5
713,0
128,4
345,2

820,8


Bang 6. Ham lugng cua cac thong s6 moi truong tai dap Ben Bap (song Dinh) va cau Cay Gang
Table 6. The concentration of the environmental parameters in water of Ben Bap dam
and Cay Gang bridge
Dap Ben Bap (song Dinh)
Cau Cay Gang
Yeu to
Dun vi
5/2008
10/2008
5/2008
10/2008
Vat la lirng
79,8
152,0
42,7
133,5
mg/l
DO
mg/l
5,5
6,4
5,1
4,0
BOD
mg/l
3.8
2,5

4,0
3,2
N0 -N
16,5
37,6
9,0
37,1
ug/1
NO3-N
59,0
167,0
73,0
181,0
Mg/l
NH,,4-N
ug/1
186,0
252,0
75.0
148,0
PO4-P
24,4
24,7
18,8
10,6
ug/1
SiO Si
ug/1
5.070.0
1.371,0

3.770,0
3.300,0
N huu ca
ug/1
1.015,0
950,0
1.035,0
860,0
P huu ca
ug/1
103,8
251,8
137,7
273,9
Hydrocarbon
1.089.0
417,0
891,0
536,0
ug/1
5

2

r

2.2. Kha nang gay anh huong cua cac
nguon thai doi voi chat lugng moi
truong khu vuc nghien cuu:
Nhirng dan lieu trinh bay d cac bang

1, 2, 3, 4, 5, 6 cho thay cac nguon thai (sinh
hoat khu dan cu, nuoi trong thiiy san, vat
chat tir song suoi,...) do vao thiiy vuc
nghien ciru deu co dac diem chung la chira
nhieu chat dinh dudng, huu ca, dau ma,
coliform. Ngoai ra, cac hoat dong nuoi torn
dia da do vao vuc nude nghien cuu mot
lugng bun rat ldn, bun ao nuoi torn chira
mot lugng ldn chat huu ca khong chi a tang
mat ma con den ldp biin 30cm do tich luy
trong suot qua trinh nuoi. Lugng biin day
nao vet tir cac ao nuoi torn co the dat den
20m /1.000m (Lai Van Hirng, 2004). Mat
khac tir lugng biin chira nhieu vat chat la
limg, giau chat huu ca nay trong tinh trang
yem khi thi thudng hinh thanh nhieu khi
doc hai nhu ammonia, nitrite va dac biet la
cac khi chira luu huynh ciing dugc phong
thich trd lai moi truong nude, gay nen
3

nhung tac hai cho ddi song ciia sinh vat.
Viing dinh dam Nha Phu la nai nhan
true tiep nguon vat chat tir cac song suoi do
vao va lugng vat chat nay gia tang rat ldn
vao miia mua lu. Lugng vat chat do song
Dinh do vao thiiy vuc nghien ciiu trong
miia mua do Pham Van Thom va cs.
(1998) udc tinh dugc mo ta d bang 7 va
thanh phan nude tai dap Ben Bap vao miia

mua nam 1997 va nam 2008 dugc mo ta d
bang 8. Cac dan lieu tir bang 7, 8 cho thay
lugng vat chat tir song Dinh do vao dam
Nha Phu trong miia mua nam 2008 ldn han
so vdi miia mua nam 1997. Khoi lugng vat
chat tir cac song suoi con lai nam xung
quanh dam, cho den nay van chua co
nhirng nghien ciiu va thong ke chi tiet, tuy
nhien qua so lieu phan tich d bang 6 tai
tram cau Cay Gang (nai giao nhau ciia 2
con song Nga Hau va Nga Da) cho thay
lugng vat chat do vao thiiy vuc tir he thong
song suoi nay la dang ke.

2

Bang 7. Luang vat chat do song Dinh do ra thiiy vuc nghien cuu trong miia mua (10/1997)
Table 7. The amount of material by Dinh river flowing into study area in rainy season (10/1997)
Yeu to
Lirong vat chat
BOD (kg)
1.077.255
Vat la lirng (kg)
49.530.357
N0 -N (kg)
11.684
NO3-N (kg)
145.464
PO4-P (kg)
7.069

Sid-Si (kg)
2.318.552
2

61


Bang 8. Ham luong ciia cac thong so moi trudng nude tai dap Ben Bap (song Dinh)
trong cac nam 1997 va 2008
Table 8. The concentration of the environmental parameters in the water of
Ben Bap dam in 1997 and 2008
Yeu to

Dap Ben Bap
10/1997 (*)
10/2008
106,0
152,0
7,1
6,4
2,3
2,46
25,2
37,6
106,0
167,0
112,0
252,0
15,0
24,7

741,0"
950,0
198,7
251,8

Don vi

Vat la lung
mg/l
DO
mg/l
BOD
mg/l
N0 -N
ug/1
NO3-N
ug/1
NH , -N
ug/1
PO4-P
ug/1
N huu ca
ug/1
P huu ca
ug/1
(*): Pham Van Tham va cs. (1998)
5

2

3 4

bien (mot lupng ldn chat thai ciing dupe
thoat ra bien), con khdi nude bien ngugc
lai di vao trong dam, qua trinh nay lam
dieu hda khdi nude trong dam va tao nen
ddng chay dac trung (Bui Hong Long,
1996). Nude trong dam chay hai chieu theo
hudng tay bac - ddng nam, nhd ddng chay
ma khdi nude trong dam chuyen ddng va
luon dugc xao trgn, tao dieu kien cho cac
chat dinh dudng, chat huu co,...ludn dugc
trao ddi giira cac khu vuc khac nhau trong
dam ciing nhu trong vinh, dd cung la
nguyen nhan chinh lam thiiy vuc nghien
ciiu cho den nay cd chat lugng mdi trudng
van con tuong doi tdt, dat biet la khu vuc
vinh Binh Cang.

IV. THAO LUAN
Khu vuc nghien ciiu tiep nhan nguon
nuac ciia mot so song, suoi, trong do song
Dinh co luu luong Ion nhat, tren luu vuc
song Dinh la viing hoat dpng nong nghiep
ciia huyen Ninh Hoa. Tiep dudi la vung
dan cu tap trung vdi nguon thai sinh hoat
do true tiep vao dam Nha Phu, xung quanh
khu vuc nay ngudi dan con phai chiu su 6
nhiem ciia miii hoi thoi boc len tir nude
thai sinh hoat va dac biet gay gat vao

nhirng ngay nang nong. Hoat dpng nuoi
torn sii va torn the chan trang phat trien kha
soi noi cung la nguon 6 nhiem dang ke.
Nhu vay lugng chat thai dang ke ma
nghe nuoi torn thai ra cong vdi luong nude
thai sinh hoat, lupng vat chat tir song suoi
(chira nhieu chat gay 6 nhiem nhu huu ca,
dau md, coliform) do vao thiiy vuc nghien
ciru ngay cang gia tang se gay nen nhung
tac dong tieu cue den thiiy vuc tiep nhan
(dac biet la viing dinh dam). Co the noi
rang, chinh nhirng nguon thai tren da lam
gia tang miic dinh dudng, chat huu co va
hydrocarbon tai vuc nude nghien ciiu, lam
anh hudng den chat lupng mdi trudng dam
Nha Phu - vinh Binh Cang.
Tuy nhien, do dac thii ciia thiiy vuc
nghien ciiu dd la kha nang trao ddi nude
manh lam cho khdi nude trong dam luon
dupe thay ddi, nude dd ra tir cac song sudi
a viing dinh dam nhanh chong dupe dua ra

V. KET LUAN VA KIEN NGHI
Tir cac dan lieu trinh bay tren day cd
the neu len mot sd nhan xet sau:
Mot vai thdng sd trong mdi trudng
nude (oxy hda tan, vat lo limg, nitrate,
ammonia) tai khu vuc dam Nha Phu (chii
yeu 0 viing dinh dam) cd gia tri vupt
GTGH dugc quy dinh trong cac tieu chuan

nude nudi trong thiiy san Viet Nam,
5943:1995 va ciia cac nude ASEAN hien
hanh, the hien rat rd ret vao mua mua, khi
lupng nude (chira cac chat thai) rira trdi tir
dat lien theo song sudi dd vao dam Nha
Phu. Chat lugng mdi trudng d vinh Binh
Cang tdt hon so vdi d khu vuc dim Nha
Phu.
62


giai phap bao ve su dung hop ly. De tai
hop ddng, Vien Hai duong hoc, Nha
Trang.
Lai Van Hiing, 2004. Danh gia miic do d
nhiem dam Nha Phu va de xuat cac giai
phap cai thien va bao ve mdi trudng
phuc vu cho NTTS. Bao cao khoa hoc,
trudng Dai hoc Thiiy san Nha Trang.
Le Thi Vinh, Pham Huu Tam, Duong
Trong Kiem, Nguyen Hong Thu, 1996.
Hien trang mdi trudng dam Nha Phu vinh Binh Cang. Bao cao de tai cap co
so, Vien Hai duong hoc, Nha Trang.
Pham Van Thom, Le Thi Vinh, Pham Hiru
Tam. Duong Trong Kiem, Nguyen
Hong Thu, 2005. Bao cao ket qua khao
sat mdi trudng cac khu vuc nudi trong
thiiy san tinh Khanh Hda. Thdng tin
KHCN tinh Khanh Hda.
Pham Van Thom, Le Thi Vinh, Pham Hiru

Tam, Duong Trong Kiem, Nguyen
Hong Thu, Le Lan Huong, Mai Van
Thang, Nguyen Kim Hda, 1998. Hien
trang mdi trudng nude song Dinh
(Ninh Hda) - Cac bien phap bao ve va
khai thac sir dung theo nguyen tac phat
trien ben vung. De tai hop ddng vdi
tinh Khanh Hda.
Phong Thdng ke huyen Ninh Hda, 2007.
Bao cao tdng ket cudi nam 2007.
Phong Ndng nghiep huyen Ninh Hda,
2007. Bao cao tdng ket cudi nam 2007.
World Health Organization, 1993. Assessment of air. water and land pollution, a
guide to rapid source inventory
techniques and their use in formulating
environmental
control
strategies.
Geneva, pp. 91-96.

Anh huong ciia cac chat thai doi voi
moi truong nuoc the hien ro ret tai viing
dinh dam Nha Phu. Ham luong cao ciia vat
lo limg, muoi dinh duong, chat huu co,
kim loai nang thuong tap trung cao 6 cac
tram 1, 2, 3 (thuoc viing dinh dam).
Thiiy vuc nghien ciru da va dang tiep
nhan va chiu anh hudng mot luong nhat
dinh chat thai tir cac nguon khac nhau nhu:
sinh hoat khu dan cu, nuoi trong thiiy san,

vat chat tir song,...Tuy nhien, do nhirng dac
thii ve che do thuy van, kha nang trao doi
nude manh, do do chat luong moi trudng
ciia thiiy vuc nghien ciiu cho den nay van
con tuong ddi tdt.
Be cai thien chat luong mdi trudng
nude ciia dam Nha Phu - vinh Binh Cang
nham tranh su suy thoai chat luong mdi
trudng nude tai khu vuc nghien ciiu, nganh
Ndng nghiep can phoi hop vdi co quan
chiic nang lien quan tien hanh quy hoach
lai viing nudi, giam sat cac nguon thai.
LCJI CAM ens
Cam on cac anh chi em d UBND xa
Ninh Phii, Ninh Loc, Ninh Ha, Ninh Ich,
phong Ndng nghiep huyen Ninh Hda da
giiip chiing tdi thu thap sd lieu phuc vu cho
bai bao.
TAI LIEU THAM KHAO
APHA, 2005. Standard methods for
examination of water and wastewater.
21 edition, American Public Health
Association, Washington D.C.
Bui Hong Long, 1996. Dieu tra hien trang
mdi trudng nguon loi chii yeu vinh
Binh Cang dam Nha Phu. kien nghi cac
st

Ngudi nhan xet:
- TS. Bui Hong Long

- TS. Doan Nhu Hai

63