INGHIENCLU
^
Kha nang tiep nhan nirdc thai cong nghiep cua song Hau theo djnh hirdng phat trien kinh te - xa hpi den nam 2020
PHAM THANH NHON
Ban Qudn ly cdc khu che xudt vd cdng n^iip Cin Thd
Nghien cihi dUac thUc hien dvta tren liAi /i/cmg ntfcfc thdi phdt sinh tit cdc khu cdng nghiep (KCN) thdi ra sdng Hau (doan tCf Vdm Cong den cdu Cdn Tha) vd cdc kich bdn phdt trien kinh te-xdhoi (KT-XH) den ndm 2020. Vcfi li/u li/ang hien tgi, sdng Hdu chi cd khd ndng tiep nhdn nguon nt/dtc thdi t^KCN Trd Ndc vd KCN Thot Not doi vdi cdc thdng so BOD, COD, Tong Nitcf (TN) vd khdng con khd ndng tiep nhdn nguon nUdfc thdi doi vdi thdng so 755 vd Tong ph6tpho (TP). So vcfi cdc kich bdn di/bdo den ndm 2020 cho thay, khi micfc thdi dttac xCtiy dat QCVN 40:2011 - cot A thi trong cdc thdng sodwac chpn (BOD, COD, TN, TSS vd TP), sdng Hdu chicd khd ndng tiep nhdn doi vdi thdng soTN.
T
he study focuses on wastewater carrying capacity by measuring wastewater flows from industrial paries discharged to Hau river (the area from Vam Cong fair to Can Tho bridge) and using scenarios of socioeconomic development in 2 0 2 0 . With current flows, Hau river is only capable of receiving wastewater from Tra Noc Industrial Zone and Thot Not Industrial Park for parameters of BOO, COD, TN and is no longer capable of receiving wastewater for TSS and TP parameters.With scenarios forecast in 2 0 2 0 , it is found that w h e n the wastewater is treated tomeetQCVN40:2011- ColumnA (Vietnamese Standard), Hau river is only capable of receiving N parameter.
I . M d D A U
Sdng Hiu li ndi tilp nhan nflde thii tfl song, kenh, rach vi eie hoat dpng san xuit ndng nghiep, din sinh, die bilt li eie KCN ven sdng. Nam 2005, khoang 4,26% Iflpng nflde thii cdng nghiip dflpc xfl ly dat tieu chuan mdi trfldng trfldc khi xa ra nguon nflde (Bd TN&MT, 2005). Tmh den dau nam 2008, khoing 20 KCN, cum edng nghiep tip trung dpc sdng Hiu chfla cd he thong xfl ly nflde thii (HTXLNT) di vio hoat dpng (Pham Dfle Nghia va ctv, 2009). Do so Iflpng cac KCN dpc sdng Hau cd HTXLNT rat it nin phan ldn nflde thii sau khi dfldc xfl ly sd bp diu xi ra sdng Hiu.
Cic nghien cflu trln the gidi vi Viet Nam thfldng tip trung md phdng tii Ifldng chat Ifldng nUdc vi kha ning tfl lam sach cua sdng bang mo hinh Qual 2E (N.Mehrdadi, M.Ghobadi, T.Nasrabadi va H.Hoveidi (2006), N.C.Ghosh va Edward A.McBean (1996), TMDL (Kevm O'DonneU va Nathan Bailey, 2008), Streeter - Phelps (E.O.Long va D.O.Omole, 2008), md hinh WQ993 - Water Quality 99 -1993 (Ll Trinh, 1995), phan mim MIKEll (Pham Thi Hdng Gia, 2010), md hinh ECOSMO (Bui Hdng Long va Nguyen Hflu Huan, 2011). Rieng ddi vdi sdng
Hiu thi chfla cd danh gia chuyin siu vl khi nang chju tii mdi trfldng.
Nghiin cflu dflpc thflc hi^n nham tinh toin, dfl bio tong tii Iflpng thii tfl eie KCN dfla trln kjch bin thay ddi dilu ki?n biln vi xac djnh khi nang tilp nhin nflde thii cia doan sdng, Iam CO sd eho nghiin cflu khi ning chiu tai cfla tuyen sdng Hiu vi phuc vu cho cdng tic quan ly mdi trfldng ciia cd quan chuyin mdn.
II. PHAM VI vA PHlTONG P H A P NGHIEN CUtJ
2.1. Pham vi nghiin cflu: Nflde thii tfl cic KCN dpc sdng Hau (doan tfl ben phi Vim Cdng din eau Can Thd).
2.2. Phfldng phap thu thip tai lilu thfl cap
Dfla trln cic cdng trinh nghiin cflu, tdng hop eic tii lieu cd tiln quan.
2.3. Phfldng phap thong kl vi titfp cin dfla trln nguyen tac quan ly tich hdp tflu vfle sdng
Kl thfla, phin tich va tong hpp cie ngudn tii Ueu de danh gii, thu thip thdng tin ve dilu kien tfl nhiln vi KT- XH; kit qui nghien cflu cfla cic chfldng trmh, de tii khoa hpc, dfl an; bin d6 Iflu vfle sdng; kit hpp thdng kl, thu thip s6 UQU, khao sit thye dja de bilu dien trln ban dd; phin tich, dinh gii tii U|u.
Sd 7/2014 H61 trtidng 65;
0
NGHIEN CCfU I &kf^-.']Sisfe^*.'^2.4. Phfldng phap tinh toan kha BTNMT ngay 19/3/2009 cua Bd nflde. kha nang tilp nhSn nflde thii nang chiu tai TN&MT quy dinh dinh gii kha cua ngudn nflde doi vdi chat 6 nhilm Can cfl Thdng tfl 02/2009/TT- nang tiq> nhin nflde thai cua nguon dfloc tinh theo phfldng trinh sau:
Khd ndng tiep nhdn cua nguon nUdc dot vdi chdt o rdtihn
Tdi luang 6 nhiim tdi da cda dtdt 6 nhiim
Tdi lUdngd nhiim sdn co trong nguon nUdc cua chdt 6 nhiim
2.4.1. Tinh todn tdi lUdng 6 nhiem toi da cua chdt 6 nhiem
Trong dd: L,^ (kg/ngay) tii Iflpng d nhilm toi da eua nguon nflde doi vdi chat d nhiem; Q (mVs) - lflu Ifldng ddng chay tfle thdi nhd nhat d doan sdng can dinh gii trfldc khi tilp nhin nflde thii, (m^/s); Q^
(m Vs) - lflu Ifldng nflde thai ldn nhat;
C|^ (mg/1) - gia tri gidi han ndng dp chat d nhiim dang xem xet dflpc quy dinh tai quy chuan, tilu chuan chat Ifldng nflde de bao dam mue dich sfl dung cua ngudn nflde; 86,4 - he sd chuyen ddi ddn vi tfl (mVs)*(mg/l) sang (kg/ngiy).
2.4.2. Tinh todn tdi lUdng 6 nhiim co sdn trong nguon nUdc tiep nhdn
L^ = Q / C * 86,4 Vdi L^ (kg/ngay) - tii lUpng d nhiem ed san trong ngudn nflde tiep nhan;Q (mVs)-lflu Ifldng ddng chiy tfle thdi nhd nhit d doan sdng can dinh gii trfldc khi tiep nhan nflde thii; C^ (mg/l) - gia tri ndng dp cflc dai cfla chat d nhilm trong ngudn nflde trfldc khi tilp nhin nflde thai;
86,4 - he sd chuyin doi dOn vi tfl (m^/
s)*(mg/l) sang (kg/ngiy).
2.4.3. Tinh todn vd dUbdo tong tdi lUdng nguon 6 nhiim do cdc KCN tren dia bdn TP. Cdn Thd thdi ra song Hau
a. Cd sd tinh todn vd dU bdo tong tdi lUdng
Cac kich bin tinh toin d nhiem trln sdng Hau ddi vdi 5 thdng sd TSS, BOD3, COD, N tong, P tdng dfla trln hifn trang d nhiem nguon nflde, hien trang xi thai vi xfl ly nflde thii cdng nghiip vi djnh hfldng quy
hoach phit trien KT-XH den nam 2020. Lflu Ifldng thai tfl cac KCN dfldc tinh dfla vid he sd phat thai, nong dp chat d nhiem cua thdng sd trong nflde thai.
- Kich bdn 1: Ndng dp thai hiln tai gifl nguyen; Cd sd mdi xfl ly dat QCVN 40:2011 (Cot B).
- Kich bdn 2: Cd sd cu xfl ly dat QCVN 40:2011 (Cdt B); Cd sd mdi xfl ly dat QCVN 40:2011 (CptB).
- Kich bdn 3: Cd sd cu xfl ly dat QCVN 40:2011 (Cdt A).: Cd sd mdi xfl ly dat QCVN 40:2011 (Cdt A).
b. PhUdng phdp tinh todn
* Hiln tai: Tai Iflong hiln tai (L^-_^ ta,) = Lflu Ifldng thii hiln tai (Qi^. ^) X Ndng do thii hiln tai
* Kich bdn 1
- Tong Tii lUpng (L)=Tai Ifldng hiln tai (L,^, ^ )-l-Tai Ifldng dfl kiln - Tai Ifldng dfl kien (L^^ ^J = Lflu Ifldng dfl kiln (Q^ ^.) x CQC (B)
- Lflu Ifldng dfl kien (Q^ ^^^,J = Diln tich lap day (S) x He sd nflde thii
Trong dd:
- Dien tich lap day (S): vdi gia thiet den 2020, 100% KCN dflpc lap
day.
- He so nflde thai: 32mVha (Quy djnh cfla Bo Xay dfli^ he so nflde la 40mVha. Lfldng nflde thai bang 80%
Iflpng nflde cap)
- CQC (B): Ndng d^ thai theo QCVN 40:2011 (Cdt B)
* Kich bdn 2: Tong tai Iflpng thii (L) = Lflu Ifldng thai (Q) x CQC (B)
* Kich bdn 3: Tinh nhfl kich ban 2, thay CQC (B) bang CQC (A)
2.5. Tinh toan kha nang tilp nhin nflde thai
•L„ = ( L „ - L . - L , ) » F Vdi Lj^ (kg/ngiy) - kha ning t i ^ nhin tii Iflpng chat d nhiem cfla ngudn nflde; L^^, L^, L^ dflpc xac djnh d phan tren; F^ - he sd an toin.
Neu gia tri Ltn ldn hdn (>) 0 thi ngudn nflde vin cdn kha nang t i ^ nhin ddi vdi chat d nhiem. Ngfldc l^ii, neu gia tri Ltn nhd hdn hoac bang (<) 0 ed nghia la ngu6n nflde khdng cdn khi nang tilp nhin dfii vdi chat d nhiem.
III. KET QUA VA THAO LUAN 3.1. Anh hfldng cua phat trien cdng nghiep din chSt Ifldng nflde mat song Hiu
Ddng bang sdng Cflu Long (DBSCL) cd 111 KCN vi ciim cong Bang 1. Thanh phan 6 nhiem chinh co trong nflde thai tai cAc KCN, CCN
TT Thong so 6 n h i i m OVT Ket q u i ' ^ ' ^ B T O M T ' " ' TSS
BOD5 COD N, P, Dau dong thuc vat
Coliform
mg/l mg/l mg/l mg/l mg/l mg/l MPN/IOOmI
400-500 250-1.000 500-1.250 50-400 10-30 20-100 2-4,6x10*
(Nguon: Chi cue Moi trUdng Tdy Nam bg, 2012) 661 Mot trtidng 5d 7/2014
NGHIEN I
^
nghiip, 119 CO sd che biln thfly sin vdi cong suat 3.200 tan/ngay (Nguyln Xuan Hiln, 2009). Do phin ldn nflde thai phat sinh tai dc doanh nghiip diu xa ra sdng Hiu sau khi da dfldc xfl ly sd bd da gdp phSn lim tang him Iflpng cdc <^t 6 nhilm trong moi trfldng ntldc sdng Hiu.
Ket qua phin tich eho thay, nflde thai phat sinh tfl cac KCN cd ham IflOi^ diat d nhilm kha cao vi vfl^
quy chuan Viet Nam gap nhieu lan.
Do dd, nlu khdng dflpc xfl ly dat quy chuin thi diy se la ngudn gay d nhilm ldn doi vdi sdng Hiu.
3.2. Dfl bao t6ng tai Ifltfng thai nguon 6 nhilm cua cac khu cdng
nghiep theo quy hoach phat trien kinh te - xa hoi
Dfla vao cac kich ban, tai Ifldng d nhilm ddi vdi 5 thdng s6 chit Ifldng nflde (TSS, BOD^, COD, N tdng, P tdng) khi cao, die bi|t khi nflde thii chfla dfldc xfl ly dat QCVN (Bang 2).
Ltlulif^ng (m'/ngiy)
1 ^ Itf^ng Lt (kg/n^r)
BOP, (mgOj/1) COD(mgOj/l) T 3 n g N { i i ^ ) T 8 n g P ( i i ^
1 2 3 4
TP Can Tho Tlnh An Giang Tinh D6ng Tliap Tlnh \%ih Long i S n g c6ng
17000 8144 22784 18211 66139
1575 3816 30758 5754 41913
800 3430 30385 6010 4062S
2363 4275 38278 7462 52378
630 '308 1278 605 2821
97
389 144 705 Kfch b i n
1 2 3 4
TP. Can Tho Tlnh An Giang Tlnh D6ng Thap Tlnh Vinh Long ISng cfing
78132 29344 102016 50368 259860
6963 5936 38682 8980 60561
13567 4490 34346 7616 150019
10445 ,7875 _ I 50163 '8689 ,77172
1 2 3 4
TRCSn Tlia TTnh An Giang Tlnh Dong Tli^p Tlnli Vinh Long T3ngc6ng
78132 29344 102016 50368 259860
6963 2934 4 10202 4737 24836.4
3567 14672 5101 2398 12533.2
10445 4401.6 15302 2960 33108.6
2786 1173.7 4081 1785 9825.7
435 2 176 612 287 1510.2
1 2 3 4
TRCan Tlio Tlnh An Giang Tlnh D5ng Thap Tlnh ^^nh Long ISngcfinK
78132 29344 102016 50368 259860
3907 1467 5101 2518.4 12993.4
2344 880 3060 1511 7795
5860 2201 7651 36276 19339.6
1332 586 2040 978 4936
312.8 117 406 2014 1037.2
3.3. Kha nang tiep nhan chSt 6 nhilm c&a song Hiu ddi vdi cac KCN
*KCNTh6tN6t
Kit qua tinh toan cho thay, trong 5 thdng so dflpc chpn dinh gii thi TSS vi TP deu cd gii trj LLtn im (dao dpng lan Ifldt tfl -43.431 din -42.965 kg/ngay va -137 din -98 kg/ngiy). Chflng td sdng H4u khdng cdn kha nang tilp n h ^ ddi vdi thdng so TSS vi TP, chi cd khi ning tilp nhin ddi vdi cic thdng s6 BOD, COD. TN tfl nflde thii KCN Th6t Ndt.
SI -10000
i
a -20000
I
= -30000 -40000 -SOOOO
I
• Htf n t^i • Kjch ban 1 va 2 • Kjch ban 3
A Hlnh 1. Khd ndng tiep nhdn chdt 6 nhiem cua song Hau dot vdi niidc thdi KCN Thot Not
56 7/2014 MoltrtidDg-67
mNGHlENCOU .?--
* KCN Tra Ndc
Kha nang tiep nhin nflde thai tfl KCN Tri Noc 1 va 2 cung tfldng tfl KCN Thot Not, trong dd TSS vi TP diu ed gii tri L^„ im (dao dpng tfl-15.953,5 din-15.653,5 kg/ngiy va tfl -59,5 din -47,5 kg/ngiy) , do do sdng Hau ehi cd kha nang tiep nhin ddi vdi thdng sd BOD, COD, TN va khdng cdn kha nang tiep nhan doi vdi thdng sd TSS vi TP tfl nflde thai eua KCN Tri Noc 1 va 2.
• K j c h b a n 1 . 2 v a 3 A Hinh 2. Khd ndng ti^p nhdn chdt 6 nhiim cua sdng Hdu doi vdi nude thdi KCN Trd Ndc
* Cac Khu cdng nghiep ven sdng Hau Trong 5 thdng sd dflpc chpn dinh gia, sdng Hau ehi co kha nang tilp nhan nflde thai ddi vdi TN cd gia tri >0 tai thdi diem hiln tai (L114,25 kg/ngiy) va kjch bin 3 (540.5 kg/
ngay). D\i bio din nam 2020 qua kich bin 1 vi 2, sdng Hau se khdng the tilp nhan ca 5 thdng sd TSS, BOD, COD, TN, TP Chi trong dieu kiln ly tfldng khi toin bd nflde thii tfl cic KCN diu dfldc xfl ly dat QCVN 40:2011-Cdt A thi sdng Hiu ed kha ning tilp nhin lai ddi vdi thdng sd TN. Rieng ddi vdi eac thdng sd cdn lai, mac du khi nang tilp nhin cd chuyen biln tich cflc hdn qua cac kich ban nhflng kha nang chiu tii eua sdng Hau vin chfla dap flng.
A Hinh 3. Khd ndng tiep nhdn chdt 6 nhiem cua song Hdu doi
r^
vdi nude thdi KCN
IV. KET LUAN - KIEN NGHI 4.1. Ket luan
Dfl bio dflpc tii Ifldng nflde thii tfl cac KCN doe sdng Hau lim cd sd dinh gii khi nang chju tai cua sdng Hau ddi vdi cic thdng sd nhfl TSS, BOD, COD, TN vi TP din nim 2020.
Sdng Hiu chi c6 khi ning tilp nhan nflde thii tfl KCN Tra Ndc va KCN Thdt Ndt doi vdi thdng sd BOD, COD va TN va khdng cdn kha ning tilp nhin nflde thii ddi vdi thdng sd TSS vi TP.
Qua cic kich ban cho thay sdng Hiu khdng cd kha nang tilp nhan nflde thii ddi vdi cic thdng sd BOD, COD, Tong N, Tdng P va TSS tfl cae KCN trln toan tuyen sdng Hau.
4.2. Kien nghi
Tiep tuc nghien cflu de tinh toan va dfl bio tai Iflpng chat thii, kha nang tiep nhan chat thii eua sdng Hiu do cic tic ddng khac nhfl ndng nghiep, thfldng mai, sinh hoat, giao thdng van tai, y te, nflde
mfla chiy tran... Qua do, tinh toin va dinh gii kha nang tilp nhin ngudn nflde cua sdng Hiu trln cic linh vfle.
Md rpng nghiin cflu flng diing eic md hinh tinh toin nham md phdng khi nang chiu tii cia sdng Hiu theo thdng so, theo mua cfla khu vfle ven song Hau. So sanh kit qui tinh theo phfldng phap tren vdi ket qui md phdng eua mo hinh tinh toan de cd biln phip quin 1^
toan diln va hieu qua hdn»
TAI LIEU THAM KHAO
Bo TMdi-MT 2005 Bdo cdo hien trang moi trUdng quoc gia nam 2005
Bill Hong Long vd Nguyin Milu Huan 2011. Nghien cilu khd ndng ti^ lim sach, de xudt cdc gidi phdp nham hao viva cdi thin chdt iUdng moi trUdng ddm Thuy Trieu - vinh Cam Ranh.
Chl cue mdi trUdngkhu vUc Tdy Nam ba 2012 Bdo cdo tong hdp nhiim vu, Dieu tra, khdoidt, ddnh gid khd ndng chiu tdi mdi tnldng dia ha lUu sdng MeKong vd xdy dUngcd id di} heu moi tnldng phuc vu cong tdc kiem sodt 6 nhilm moi trudngnudc viing n^ien cilu. Cue kiim soat 6 nhiim. TSngcuc MOI tnidng
Nguyen Xuan Hien 2009. Nguon tdi nguyen cua DBSCL Tap san Khoa hoc vd cdng n^e quy hoach thdy\di. Viin Quy hoach Thiiy ldi mien Nam Pham DUc N^iiii vd ctv 2009 N^ien cdu dp dung mo hinh hai chieu Mike 21 ecolah tinh todn chdt luang nUdc tren song Hdu (doan til LongXuyin dSn Cdn Thd) Vien Khoa thuy lai Mien Nam
Pham Thi Hong Gia. 2010, N^iincvlu xdc dinh cdc he so ddnh gid khd ndng tU lam sach cua song Ap dung thd n^iim trinluu vUc sdng Sdi Gdn, Vii» MTd-wr Dai hoc Quoc gia TPHCM
Kevin O'DonneU vd Nathan Bailey 2008 Fecal cohform TMDL for the Cocohatchee River estuary, WBID 3259A Pat Fricano Florida Department of Environnicnliil Protection Bureau of Watershed Management Watershed Planning and Coordination Section.
N Mehrdadi, M Chabadi, T Nasrahadi, H Hoveidi. 2006 Evaluation of the Quality anh self purification folential of Tajan river using Qua\2e model.
Faculty of the Environment. University of Tehran. Tehran. Iran
-v3 681 Mol trtidng So 7/2014
