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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3

3

6

ENVIRONMENTAL QUALITY OF NHA PHU LAGOON - BINH CANG BAY
WITH RELATION TO THE ECONOMIC ACTIVITIES

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

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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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:

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

0

34

2

3

4

3

4

5

Si0 -Si
3

3

4

5

6 9
Tr

m


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)

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
7

5"

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

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

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

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

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

(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

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

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

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

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

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

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
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2

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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

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

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)
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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

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,

- TS. Doan Nhu Hai

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