71 nghien cuu xu li nuoc thai cho tren mo hinh

j^msasMBM

23

NGHIEN CUU XU'LY NUlSC THAI CHOfTREN MO HINH
HdP KHOI BASTAF - BAI LOG NGAM TRONG CAY
• l.&m\lnhSfSn - Dai hoc Ky Thu4t CSng Nghe Tp. Ho Chi Minh, ViStNam
LSm Hoang Vu - Dai hoc Khoa hoc Tu nhien Tp. HS Chi Minh, ViitNam
T6M TAT
Ntfdc thai chd tff Idu dtfdc bidt den la tdc nhan gay 6 nhidm Idn ddi vdi ngu6n ntfdc. Tuy
nhien, hien tai ntfdc thai d cdc chd deu thai trtfc tiep ra sdng, sudi hodc he thdng cdng ntfdc
thai sinh hoat chung cua khu vtfc ddn ctf xung quanh. Sd dT hau hdt cdc chd khdng xl^ ly ntfdc
thai la do quy md chd con nhd khdngdiikinhphidddluttfxdy dtfng he thdng xffly dat yeu
cau. Vdi nhffng van dd xuaft phdt tijf thtfc tiln d'y, mot he thdng vdi chi phi xdy dtfng thap
nhiTng hi$u qua cao va dn dinh dtfdc nghiSn ciJu la md hmh hdp khdi BASTAF - bai loc nglm.
Theo nghidn ctfu, md hinh hdp khdi BASTAF - bai Ipc nglm dtfdc vdn hanh theo nguyen
tac ddng ntfdc ttf chay. Trong do, be BASTAF la be ky khi vdi 5 ngdn: 1 ngan chtfa, 2 ngan
phan buy sinh hpc ky khi vd 2 ngdn Ipc ky khi. Bai Ipc ngam trdng cay Trau bd trang
(Syngonium Podophyllum) cd dien tich be mat Id 0,24 m^ Ntfdc thai lay ttf chd Dau mdi Nong
san Tbii Dtfc. Chay mo hinh de khdo sdt thdi gian Itfu tditfudtfa tren hieu sua't x^ ly vd nghi6n
ctfu kha nang xii" ly ciia ttfng thanh phan trong md hinh hdp khdi. Kd^t qua cho thay thdi gian
lull tditfucua md hinh hdp khd'i la 48 gid. Vdi thdi gian Itfu 48 gid thi hi$u sud'txuT ly la 89,8%
COD; 93,7% TSS; 84,4% TP; 81,4% TN va 94,5% CoUform. Ntfdc thdi dIu ra dat quy chuan
loai A cua QCVN 24:2009/BTISIMT d hau hdt cac thdng sd. Mot kdt qua nghien ctfu khac cho
thlfy hdi Ipc ngam cd hieu suat xii ly cao hdn be BASTAF d tdt ca cdc thdng sd, ddc biet Id
Nitd tdng, Phospho tdng va Coliform.
ABSTRACT
Market's wastewater is a significant source of water pollution. However, nowadays much
market's wastewater is released in rivers, streams or domestic wastewater system in
residence area directly. Small-scale markets can not afford to invest in a standard treatment
system for causing wastewater to go untreated. In order to solve practical problems, the

treatment system with low expenses but bringing efficient and stable's result was study:
Entire System BASTAF - Constructed Wetland.
According to research, Entire System BASTAF - Constructed Wetland was operated by
the the principle of gravity flow. BASTAF was an anaerobic lank including 5 parts: one
sedimentation part, two anaerobic decomposition's parts and two anaerobicfilter'sparts. The
Constructed Wetland planted Syngonium Podophyllum with the surface area of dieriverwas
0,24 square metres. The raw wastewater was taken from the Thu Due Agriculture Wholesale
Market. Operating entire system to survey optimum retention time based on treated
productivity and researching the capability of treatment of each component in of entire
system. As a result, the optimum retention time of the entire system was 48 hours, retention
tune was 48 hours with treated productivity: 89,8% of COD; 93,7% of TSS; 84,4% of TP;
81,4% of TN and 9,5% of Coliform. The wastewater after treatment achieved A standard of •


24

«M1!lllillililJ:IJilllliyiU

• QCVN 24:2009/BTNMT, almost environmental parametes. Another study shows that
BASTAF has productivity higher than Constructed Wetland on all parameters, especially in
Total Nitrogen, Total Phosphorus and Colifrom.
LMyCTlfeU NGHIEN Ctru
Nghien cffu thanh phan vd tinh chd't cua ntfdc thdi chd da ngdnh hdng tu: dd xac dinh dtfdc
phtfdng phdp xiif ly ntfdc thdi thfch hdp.
Nghien cffu, ddnh gid khd ndng xiJ Iy ciia md hinh hdp khdi BASTAF - Bai Lpc Ngam ddi
vdintfdcthdichd.
De xua't cdng nghe xu* ly ntfdc thdi chd vdi chi phi thd'p vd than thien vdi moi trtfdng.
2. NQI DUNG NGHIEN ClTU
De dat dtfdc nhffng muc tieu de ra, nhdm nghien cffu chung tdi dd thtfc hien cdc ndi dung
sau:

- Phan tich thdnh phIn vd tinh cha't cua ntfdc thdi chd. Cu the, nhdm nghien ctfu lay mlu
ntfdc thdi tai Chd Dau mdi Ndng Sdn Thu Dffc Tp. Ho Chi Minh.
- Thidt kd mo hinh hdp khdi phuc vu nghidn cffu: mo hinh gdm 3 bd phan chinh la be chtfa
ntfdc thai, be BASTAF va bai lpc nglm trdng cay Trau Ba Trang (Syngonium Podophyllum).
- Phdn tich, danh gia kha ndng xu* ly ntfdc thai cua mo hinh hdp khdi BASTAF - Bai Lpc
Nglm tren cd sd thdi gian Itfu ntfdc.
- Khdo sdt hieu qud xu' ly ttfng thanh phIn cua be BASTAF vd bai lpc nglm
Ttf nhffng kdt qua cd dtfdc, kdt luan ve tinh khd thi cua mo hinh ddng thdi de xusTt cdng
nghe xff ly ntfdc thdi chd tren thtfc te'.
3. P H U O N G P H A P NGHIEN COU

3.1. Phffdng phap luSn:
Ntfdc thai chd chtfa nhieu thanh phIn 6 nhilm nhtftig dac trtfng chu yeu la d nhiem hffu cd,
hamltfdng giau Nitd, Photpho, vi sinh vat... Cac thanh phan nay ndu khdng dtfdc xff ly trietde
se anh htfdng den sffc kbde cua con ngtfdi, he dong thtfc vat xung quanh...
Nam dtfdc cac dac didm do, mo hinh hdp kho'i BASTSAF - Bdi Lpc Ngam trdng cay dtfdc
de xua't de xff ly triet de cac thdnh phIn 6 nhidm trong ntfdc thdi chd.
Ben canh dd, md hinh hdp kho'i cdn dtfdc danh gia tinh kha thi rdt cao khi dp dung vao thtfc
tevi chi phi thap, thdn thien moi trtfdng vd tao ra nhieu san pham phu hffu Ich.
3.2. Phffdng phap cu thd:
Nghien cffu tdng hdp t^t ca lai lieu lien quan ddn de tai nhtf cdc tap chi khoa hoc, cdc c6ng
trinh nghien cffu cd nhffng ket qua hffu ich cho de tai.
Phtfdng phap xdy dtfng mo binh: tren cd sd tinb todn thiiy Itfc, Itfu Itfdng ntfdc thdi thich hdp
de xay dtfng cac ihdng sd cd ban cho md hinh.
Phtfdng phdp chpn thtfc vat cho bai lpc nglm: thtfc vdt trong bai lpc ngam phai la loai c6
vdng ddi sinh trtfdng ngan, than cd, rd dai bdm sau dffdi cdc Idp dd't vd ddc biet cd kha ndng
lam sach ntfdc.
Phtfdng phap phan thu thap va phdn tich mdu: mdu dffdc ld'y tai chd Dau Mdi Thu DffcTpHo Chi Minh sau dd dtfdc chay md hinh va phan tich cdc thdng sd 6 nhidm tai phong thi
nghiem Khoa Mdi trtfdng - Dai hpc Khoa hpc ttf nhi6n Tp. H 6 Chi Minh.
Phtfdng phap xu' ly sdlieu: cdc sd lieu thu thap, phdn tich, tdng hdp tff kdt qud thi nghiem •

lamiiiMiiMtH'ii'ii

25

• dtfdc xu*ly bang phIn mdm Microsoft Excel 2007 vd Statgraphics Centurion XVI.
4. QUY TRINH THI NGHIEM:
4.1. Thidt kdmo hinh htfp khdi:
4.L1. Md hinh be BASTAF:
M6 hinh dtfdc lam bang vdt li$u thuy tinb day 5mm vdi the tich thtfc bd la 0,2 m' ~ 200 lit.
KIcb thtfdc be nhtf sau:
Dai X Rpng x Cao = 1 m x 0,4m x 0,5m
Be BASTAF cd 5 ngan chinh. Kich thtfdc mdi ngdn dtfdc trinh bdy trong bang 1
Bdngl: Kich thudc cdc ngdn trong be BASTAF
Kich thir6*c (m)
Ten ngan
Dai X Rpng x Cao
Ngan chija

0,4 x 0,4 x 0.5

Ngan ky khi bac I

0,15x0,4x0,5

Ngan ky khi bac II

0,15x0,4x0,5

Ngan lpc ky khi I

0,15x0,4x0,5

Ngan lpc ky khi II

0,15x0,4x0,5

Bd BASTAF dtfdc ddy kin bang mot t^m xdp, phia
tr8n mdi ngdn ddu cd dng nhtfa uPVC 019 dd khi tao
thanh trong qud trinh phdn buy sinh hpc cac hdp chd't hffu
cdnhffCH4,H2S,C02...thoatra ngoai.
Giffa cac ngan trong be BASTAF dffdc ndi vdi nhau
bang Te nhtfa uPVC 021 Cac TB ndy dtfdc lap vao be
BASTAF theo kieu dich ddc giup cho qua trinh xao trdn
ntfdc thdi va biin ky khi xay ra tdt hdn
4.2.2. Mo hinh Bdi Loc Ngdm:
Md hinh bai lpc ngam trong dd tai dtfdc thidt kdld mdt
thiing nhtfa PE hinh hop chff nhdt vdi cac thdng so:
- Thd tich vung lpc: 0,108 m'
- Di$n tich bai lpc: 0,24 m^
- Kjch thtfdc bai lpc: Dai x Rpng x Cao = 60cm x 40cm
x65cm.
H6 thdng phdn phd'i ntfdc vd thu ntfdc trong bai lpc
nglmdtfdctbidtkd tff cdc dng nhtfa PVC 021 cd due Id.
Cau true cac Idp vdt li$u lpc trong bai lpc nglm theo
chieu tff dtfdi 16n Id: sdi Idn, cat. da't trdng. Thdng sdcua
mdi Idp vat Ueu dtfdc trinh bay trong bang sau:

Hlnti 1 Mo hinh Be' BASTAF

mj7
Hinh 2: Mo hinh Bai Loc NgSm


««l!l!lill!l,IJJJilMMIU

26
Bdng 2: Vdt lieu loc trong hai loc ngitn

,, .^
The tich vilng loc '
tirong ling (m')

Loai vat li^u

Kich thirAc hat
(mm)

Kich thir^c viing
I9C (cm)

Soi Ion

8-10

6 0 x 4 0 x 15

0,036

Cat

2-3

6 0 x 4 0 x 15

0,036

Dat trong

1-3

6 0 x 4 0 x 15

0,036

*
Trong bai loc ng£m trong 8 cay Trau bjl trSng Syngonium Podophyllum va AiXtSc phan bS
dIu tren dien tich bai loc vdi trung binh: 1 cay/ 0,03 tn.
4.1.3 Lap dat mo hmh hap kho'i:
Mo Mnh hc)p khd'i difdc iSp theo nguyen t^c ddng ni/dc thdi tit chay.
Do cao cua c5c bd phan trong mo Mnh dam bao sao cho ddng nUdc thai tuf chay theo cMeu:
thiing nitdc thdi —> be BASTAF —> bai loc ngSm.

jmw^

Hinh 3- Mo hinti 3D hi)p kliSt

Hinh 4: m Wn/i h0p khSi trln thuc t(

4.2Ba'trithinghi$m
4.2.1 Khdid^ng md hinh:
• Thich nghi be BASTAF
Bun ky kh! diTdc lay tCr co'ng thoat nirdc ve sinh tai Tram xuT ly nirdc thai chd Diu moiNdng
sSn Thu Difc. Sau do, bun ky khi dirdc cho vao 2 ngSn ky khi cua be BASTAF. The tich biin
chiem khoang 1/3 th^ tich ngan ky khi. Duy tri ham lUdng MLSS (Mixed Lipuoz Suspended
Sohd - Cha't ran Id Iffng trong hdn hdp biin Idng) thich hdp cho qud trinh ph3n huy ky khi. Dau
hi6u bDn ky khi thich nghi vdi nUdc thdi chd: biin cd mau den xdm, hi mat niTdc cd nhi6u bpt
khi, van tdc bun lang nhanh, kich thudc hat bun Idn, khdng cd biin ndi tren mat nifdc.
Nirdc thai sau khi lay tii chd ve se cho vao thung chlJa va bat dIu md van chay vao be
BASTAF da chu'a biin ky khi trong vdng 10 ngay. Sau tijfng ngdy se do ham llfdng COD tai be
BASTAF de xem xet kha nang thich nghi cda md hinh vdi nifdc thdi chd.
- Trong va thich nghi c3y Tr^u Ba Tr^ng
Cay Trau ba trang trong tren bai loc ngam difdc thich nghi dan vdi mfdc thdi chd. Tlfdicay
hang ngay vdi nirdc thai chd cd nong dp tang dan tif 25% den 100%. Sau mot thdi gian (khodng^ >


EIBIlBiIliS

27

> 10-15 ngay) neu th^y cay sinh tnfdng va phat trien Id't thi cd th^ hdt dau chay md hinh.
4.2.2 Chay mo hinh:
- Xac dinh thcfi gian liAl td'i vfu
B e khdo sdtthdi gian lifu HRT (Hydraulic Retention Time) nao Id td'i Uu cho qua trinh hoat
ddng c i a hS thd'ng md hinh BASTAF - Bai Loc Ngam ta sd'dung cdng thifc sau de nghien cifu:
HRT =

_V
Q"

Trong do:
HRT: thdi gian Itfu ntfdc (gid)
V: the tich bd phdn tfng (m^).
Q: Iffu Itfdng ddng vao (m%).
Thdi gian Itfu HRT dtfdc dtfa vdo nghien cffu ddi vdi md hinh BASTAF - Bai Lpc Ngam
la T, = 36 gid, T, = 48 gid, Tj = 60 gid. Ttfdng tfng vdi nhffng thdi gian Itfu dd thi ta cd Itfu Itfdng
ddng vdo la Q, = 3,1 lil/h; Q2= 2,5 lit/h; Q3= 4,2 lit/h (thd tich chtfa ntfdc cua bd BASTAF Id 150
lit).
Ddi vdi mdi thdi gian Itfu khac nhau, ta se phan tich cac thdng sd'dd tff dd tinh hieu suat xff ly
nham tim ra thdi gian Itfu td'i uff cho cd mo hinh.
5. K E T QUA N G H I E N ClTU:
5.1. Kdt qua p h a n tich m a u nffdc thai chd:
Bdng 3: Ket qud phdn tich mdu nude ddu vdo
Gia tri
Chi tiSu
pH
7,37
TSS (mg/I)
181,7
COD (mg/1)
481,2
BOD5(mg/l)
284,0
TN (mg/1)
73,2
TP (mg/1)
18,6
Coliform
48x10'

(MPN/100ml)
Cac chi tieu mdi trtfdng trung binh cua ntfdc
thai chd khd cao, hau hdt ddu vtfdt tieu chud'n cho
phep loai B cua QCVN 24;2009/BTNMT nhieu
lan. Trong dd, TSS g^p 3,6 Idn; T N g ^ p 5,2 l l n ; T P
ga'p 10,9 Idn; BOD^ gap 9,5 l l n va COD gd'p 9,6
l^n. Ham Itfdng chat hffu cd trong ntfdc thdi cao vdi

l>cl

ty 16 BOD3/COD la 0,59 thich hdp cho xff ly bang
phtfdng phdp sinh hpc ky khi. Ngodi ra, ham Itfdng
cha't ran Id Iffng TSS, Nitd vd Phospho Idn cung la

Hinh 5: Qud trinh khdi dong mo hinh qua COD •


M'mimtimmmmiim

28

• dieu kien de chpn bai lpc ngam trdng cdy xff 1^ ntfdc thdi chd.
5.2. Ket qua thich nghi md hinh hcfp khd'i vdi nu'dc thai ch^:
5.2.1 Keiqud thich nghi cua be BASTAF
Dtfa vdo bidu dd hinh 5 ta dd ddng nhan tbd'y COD dau ra trong be BASTAF giam din tCfng
ngdy, ttfdngffngId hieu sud't xff I^ COD tdng theo. Hieu sud't tdng lien tuc tff ngay thff 1 ddn
ngdy thff 8. Hi6u sud't bat dau dn dinh khodng 70% tff ngdy thff 7 ddn ngay thff 10. Qud trinh
khdi ddng ket thiic vd cd thd bdt dau chay mo hinh.
Nguyen nhdn gilip qud trinh khdi ddng be BASTAF nit ng^n thdi gian Id do vi sinfe vat
trong bun ky khi dffdc lay ngay tai chd nen da thich nghi vdi moi trffdng ntfdc thdi chd, khdng

bi sdc vi ndng dd hodc tinh chd't ntfdc thai. Chinh vi vdy, vi sinh vat tiep tuc hoat ddng phdn
huy chd't hffu cd lam ham Iffdng COD dau ra giam nhanh qua cdc ngdy.
5.2.2 Ket qud thich nghi cua cdy Trau bd trang trong Bai Lpc Ngam:
Qua lOngaytffdi bang ntfdc thdi chd, cay Trau bd trSng sinh trtfdng vd phdt trien ra"! tdt,
khong cd cay chdt, khdng cd sdu bo. Sau mdt thdi gian, cd nhieu sinh vat di ctf ddn bai lpc
ngam sinh sdng nhtf giun, mdi, cudn chieu... giiip cho he dong thtfc vdt tai day them phong phii
gdp phan tao canh quan da dang sinh vdt cho bai lpc nglm.
5.3. Kdt qua chay md hinh hgfp khd'i vdi thcfi gian lirti (HRT) thay ddi
5.3.1 Hieu suat xHly tinh theo ham lUOng COD

-*^
Ibttin

Hinh 6: Ndng dp COD ddu ra vdt
thdi gian luu khdc nhau

Hinh 7: Hieu suat xA ly COD theo gian litu

Hinh 6 cho thay, vdi thdi gian luxi HRT = 36h thi n6ng do COD diu ra cdn Idn, khdng in
dinh, dao ddng tit 123 -190 mg/L. Cdn do'i vdi HRT = 48h thi nong dd COD dIu ra thap, khd on
dinh, xap xi quy chuan loai A cua QCVN 24:2009/BTNMT. Khi tSng thdi gian lifu len vdi
HRT = 60h thi nong do COD cung khdng giam la bao nhieu so vdi HRT = 48h. Trung binh
ndng dp COD dau ra cua cd HRT = 48h va HRT = 60h khoang 49,5 mg/L.
Tif hinh 7, tha'y dUdc hieu sua't xiJ ly vdi HRT = 36h chi khoang 70%. NgUdc lai, vdi
HRT = 48h vd HRT = 60h thi hieu sua't cao xap xi 90%, cd me hieu sua't len dg^n 95%. Sd di vdi
HRT = 36h thi Meu sua't xuf ly COD thd'p la do thdi gian luu chUa du de cdc qud trinh \\S \^ sinh y


jMosimmMEaL.

29

• hda, hda ly loai bo cdc cbd^t hffu cdo nhiem dien ra trong md hinh hdp khdi BASTAF-bai lpc
ngam.
5.3.2 Hi^usuatxitly tinh theo ham lUcfng TSS

Hinh 8: Ham Iuong TSS ddu ra vdi
thdi gian luu khdc nhau

Hinh 9: Hieu su^txA ly TSS theo thdi gian lUu

Ham Itfdng TSS ddu ra cua m6 hinh bdp khd'i BASTAF - bai lpc ngam thd'p va on dinh ddi
vdi ca 3 thdi gian Itfu khac nhau Id 36 gid, 48 gid vd 60 gid. Nhin vao hinh 8 ta tha'y tlft ca kdt
qua thu dtfdc deu dat loai A cua QCVN24:2009/BTNMT. TSS dIu ra cao nha't la 34,7 mg/L,
tha^pnhatla 5,5 mg/L.
Hieu sufTt xff ly TSS vdi thdi gian Itftf khac nhau ddu cao xa'p xi 91 %. Vdi hieu su^t trung
binh cua HRT = 36h la 89,3%; HRT = 48h la 93,7%; HRT = 60h la 91,1%. Nhtf vay kha nang
xff ly TSS cua md hinh hdp khd'i BASTAF - Bai Lpc Ngdm ddi vdi ntfdc thai chd khdng phu
thudc nbidu vdo thdi gian Itfu ntfdc.
5.3.3 Hieu suatxiCly tinh theo ham lUdng TP

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Ilir»Bi
-••SHi -*-.Bii -o-ftfe —U'ii.\-cii.'\i;:i;>"-Bnc;.[ri

Hinh 10: Ham luang TP ddu ra vdi
thdi gian lUu khdc nhau

Hinh 11: Hieu sud't xi^ ly TP theo thdi gian luu

Hinh 10 cho tha'y dtfdc ham Itfdng TP ddu ra giffa cdc me cua HRT = 36h cd sff dao dong kha
Idn tff 5,1 -10,2mg/L, trung binh khoang 8 mg/L. Hdm Iffdng TP ndy deu vtfdt so vdi loai A (<4
mg/L) va B (<6 mg/L) cua QCVN 24: 2009/BTNMT. Chinh vi vay ma hi6u sua't xff ly TP cua
HRT = 36h khd thd'p chi khoang 56,3%, cd me cao nhat cung chi 74,2%. Ddi vdi HRT = 48h vd
HRT=60h, ta tha'y hau bet cac diem tren dtfdng do thi bidu didn bam Itfdng TP cua HRT = 48h
va 60h ddu nam dtfdi diTdng thang loai A (4 mg/L). Chffng td ham Iffdng TPffngvdi 2 thdi gian •


«mil!ill,lll,IJ.IJiii|JMU

30

• Itfudddeudat loai Acua QCVN 24:2009/BTNMT. Vebiausudit xuf I^thiHRT = 36hla 84,4%
vd HRT = 60h Id 84,9%. Ddy la hieu sua't khd cao ddi vdi cong nghe xff I^ sinh hoc x6t tren chi
ti6u Phospho tdng.
5.3.4 Hifu sud't xvtly tinh theohdm lUffng TN

Hinh 12: Hdm lUdng TN ddu ra
vdi thdi gian luu khdc nhau

Hinh 13: Hieu suat xvt ly TN
theo thdi gian luu

Bieu do hinh 12 cho tha'y bam Itfdng TN dau ra cd stf khdc bidt Idn khi chay md hinh vdi thdi
gian luff khdc nhau. Hieu qua xff ly TN tdt nhd't thupc ve HRT = 60h, tiep ddn HRT = 48h, cdn
HRT = 36h thi xff ly kem nhd't. Ddi vdi HRT = 36h, bam Itfdng TN ddu ra cdn kha Idn so vdi
quy chuan loai A cua QCVN 24:2009/BTNMT. Cdn vdi HRT = 48h vd 60h thi hau hdt kdt qua
d cac me deu dat loai A. Ve bieu sua't xff ly TN, vdi HRT = 36h thi hieu suat trung binh cua cdc
me chi cd 56,4% thi hieu sua't HRT = 48h va 60h kha cao Id 81,4% vd 91,9 %.
5.3.5 Hieu sud'txAly tinh theo hdm lUdngColliform

Hinh 14: Hdm luang Coliform ddu ra
vdi thdi gian luu khdc nhau

Hinh 15: Hieu sud't xik ly Coliform
theo thdi gian luu

Dac biet ve neu xe t ve hieu sua't xuf ly Coliform thi mo hinh hdp khdi c6 kha nang xu"
ly tdt hdn so vdi tat ca cac chi tieu khac. Hi6u sua't trung binh cua HRT = 48h la 94,5%,
HRT = 60h la 92,3%, c6 nhffng me hieu sua't len den 97%. Dieu dd chiJng to kha nang
loai bd vi sinh vat gay benh cua mo hinh hdp khdi BASTAF - bai loc ngdm la ra't tdt.
5.4. Hi$u suat xu* ly thanh phan cua be BASTAF va bai loc n g i m trdng cSy

>


31

BEBUnBH
Tidn hanh chay m6 hinh hdp khdi vdi thdi
gian lifu 48 gid de nghidn cffu hi§u qua xuf ly
cua be BASTAF va bai lpc ngam trong mo
hinh hdp khdi. Ld'y mdu tai 3 vi tri Id: dIu
vao md hinh (CJ, diu ra sau bd BASTAF
(CBAS) V^ sau bai lpc ngam (C^J de phan tich

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•J

Hinh 16: Vi tri lay mdu de nghien cAu
hiiu sud't xd: ly thdnh phdn

cac thdng sd nhtf tren hinh 14.
Thtfc hien chay tdng cpng 10 me, ld'y ket qua phan tich trung binh cua cdc me. Sau
do tinh hieu sua't xu" ly cua tffng be va hieu sua't cua ca mo hinh.

c.

HBAS

Hbln

H

CBAS

Cbln

(%)

(%)

(%)

COD

481,2 mg/L

174,0 mg/L

49,4 mg/L

63,8

71,6

89,7

TSS

181,7 mg/L

58,8 mg/L

11,2 mg/L

67,6

80,9

93,8

TP

18,6 mg/L

14,3 mg/L

2,9 mg/L

23,0

80,0

84,6

TN

73,2 mg/L

55,1 mg/L

13,4 mg/L

24,7

75,7

81,7

Coll

47900

MPN/lOOmL

23960
MPN/lOOmL

50,0

91,6

95,8

CT

\,

2020
MPN/lOOmL

Bang 4: Tong hdp ket qud phdn tich cua bi BASTAF vd bdi he

ngam

Chu thich:
- KQ, CT, Coli: ket qud, thong sd', Coliform
- C,.' nong do ddu vdo mo hinh hdp khd'i tuang Ung vdi cdc thong so'
- Cg^j." nong do ddu ra tai be BASTAF tuong Ung vdi cdc thdng so'
- Ci,i„: nSng do ddu ra bdi lpc ngdm tuang ling vdi cdc thong so.
- Hg^s' HM„, H: hieu sud't xu: ly cua be BASTAF, bdi lpc ngdm vd mo hinh hpp kho'i.
Trong do:
C

H.. (%) = - ^
bln\

/

-C
100%
„

C.-C„,
H=1-(1-H,J(1-HJ


32

J^MIIIilllill.lilHJiMMia

IIJJJ
Hinh 17 Hieu sud't xi ly ciia be BASTAF
vd bdi he ngdm
Do thi cot hinh 17 cho tha'y hieu suat xiJ^ ly khdc nhau giffa be BASTAF va bai lpc ngam
trong m6 hinh hdp kho'i. Trong do, bai lpc ng^m c6 hieu suat xijf 1}? cao hPn be BASTAF d
tat ca cac chi ti§u. Cu the:
Vdi thong s6'C0D, hieu sua't xu-ly cua be BASTAF khoang 63,8% nhd hdn so vai 71,6%
cua bai loc ngam. Tuy nhien, sit chenh lech nay khong qua Idn. Nguyen nhan cQa sir khac
nhau nay la do cd che phan huy sinh hoc chat hiTu cd cua be BASTAF va bai lpc nglm khac
nhau. Neu vdi be BASTAF, chat hiJu cd bi phan huy chu yeu nhd qua ttinh ky khi thi trong
bai lpc nglm la sifting hdp cua nhieu qua trinh nhithiS'u khi, ky khi va thi^u khi.
TUdng tif la th6ng so'TSS, hieu sua't loai bo chS't ran Id ling cua be BASTAF va bai lpc
ngam lan lUdt la 67,6% va 80,9%. Nhd cac Idp vat lieu lpc nhiT sd dita, cat, dat, soi vi than

hoat tinh nen giup cho hieu sua't loc cua ca hai deu kha cao. Tuy nhifin vung lpc trong bai
lpc nglm cd the tich Idn hdn so vdi be BASTAF nen nirdc dau ra se cd liTdng chat rin Id
lijngithdn.
Ba thong so con lai la TN, TP va Cohform cho tha'y hieu suat xiy ly cua bai lpc ngam cao
hdn han so vdi be BASTAF. Ne'u nhif vdi thong so TN va TP, be B AST/^F cd hieu suat xi
ly rat thafp chi khoang 23% va 24,7% thi hieu sua't cua bai lpc nglm lai rat cap, gS'p 41lnso
vdi be BASTAF. Dieu nay chp thay qua trmh xuf ly Nitd va Phpsphp trong bai lpc ngam la
rat tot. Cd che chinh cua qua trinh nay la qua ttinh nitrit hda, nitrat hda, hap thu bdi khoang
chat cung nhuf qua trinh hap thu cua cay Trau ba trang.
Con doi vdi thong so Coliform thi hieu sua't xiV ly cua bai lpc ngam gap gan 2 lan so hieu
sua't xuf ly cua be BASTAF. Hieu sua't xuf ly Cpliform cua bai lpc nglm la 91,6%, Idn nhat
trpng tat ca cac thong so. Cd di/dc hieu sua't cap nhu' vay la dp vi sinh vat trong nifdc thai se
bi cac qua hinh trong bai lpc ngam tieu diet nhit lang, lpc, biJc xa mat trdi, cSc chit chiet
xuat tif rl thifc vat. Kha nang tieu diet vi sinh vat bang phiidng phap tit nhign trong bai Ipc
ngam se dUdc suf dung nhieu trong cac he thd'ng x i ly vi no hpan toan khSng cIn si dung
denhdachatkhu'trung.
•


j^MMmmmm^
•

33

6. KETLUAN - KIEN NGHI:
6.1.KdtIu$n:
Qua qua trinh nghien ctfu kha nang xu: ly nirdc thai chd bang md hinh hdp kho'i
BASTAF - bai lpc ngam, mot sdket luan du'dc dUa ra nhtf sau:
N^ng do cdc chd't d nhilm cua nu'dc thai tai chd Dau md'i Ndng sdn Thu DiJc khd dn
dinh, thich hdp cho vi$c khdo sdt md hinh hdp khd'i BASTAF - bai lpc ngam bang thdi gian

hiu nu'dc.
Trong qua trinh khdo sat thdi gian lifu nifdc vdi 3 gia tri Id 36 gid, 48 gid va 60 gid, thi
hieu sud't xtf ly thd'p nha't ddi vdi 36 gid. Cdn ddi vdi thdi gian lufu 48 gid vd 60 gid thi hieu
suat deu ra't cao va xap xi nhau d hau hdt cdc thong sd. Chinh vi vdy, neu xet tren vl mat
hieu qud ve thdi gian xtf ly cung nbLftidt kiem chi phi thi cd the kdt luan dtfdc thdi gian lull
ntfdc 48 gid la tditfucho md hinh hdp khdi BASTAF - bai lpc ngam.
Vdi thdi gian Itfu 48 gid, hieu sud't xtf ly ddi vdi cac thong sd COD, TSS, TN, TP,
Coliform deu khd cao, cu thd:
Bdng 5: Tdng hpp hieu sud't xH l^ cua mo hinh hdp khoi
Hieu su^t thanh phan (%)

Thdng s6

Hieu suSt md hinh
hop ldi6i (%)

BASTAF

Bai loc ngam

COD

89,8

63,8

71,6

TSS

93,7

67,6

80,9

TP

84,4

23,0

80,0

TN

81,4

24,7

75,7

Coliform

94,5

50,0

91,6

Kdt qud phdn tich cdc thdng sdnude dau ra vdi thdi gian liTu 48 gid cho thd'y td't ca cdc thdng
sddeu dat quy chu£n loai A cua QCVN 24:2009/BTNMT.
Ve kha nang xtf Iy cua ttfng thdnh phan trong md hinh hdp khd'i thi bai lpc ngam cd hi6u
suat cao hdn be BASTAF d td't ca cac thdng sd. Dac biet, vdi thdng so Nitd tdng, Phospho tdng
vd Coliform thi uXi thd ve khd ndngxtf 15'cua bai lpc nglm so vdi be BASTAF thd hien rd ret
nhSft.
Md hinh hdp khdi BASTAF - bai lpc ngam ra't thich hdp de xtf Iy nifdc thai chd va cac loai
nu'dc thai khdc c6 tinh cha't tifdng tif.
6.2, Kidn nghi:
Sau mot thdi gian tien bdnh thtfc hi6n di tai nghien ctfu nay, nhieu va'n de, nhieu y tifdng
da ndy sinh trong qua trinh xay dtfng md hinh, lay mdu, chay md hinh, phdn tich mlu... nhiTng
do kien thtfc va thdi gian thtfc hien dl tdi cdn han che n§n nhdm nghien ctfu chUa the giai k


34

J-«M«illlill!lill:IJilll

P I

• quydt dtfdc td't cd. Vd sau ddy Id mdt sd'kidn nghj cua sinh vien vl htfdng phdt trien cua dl tai:
- Khao sdt dnh htfdng cua tdi trpng d nhiem khdc nhau d6'n hidu sud't ci5a mo hinh khi xtf Iy
nhffng loai ntfdc thdi cd n6ng dd ch^t thdi dao ddng Idn.
- Tien hdnh nghiSn ctfu khd ndng xtf 1^ ntfdc thdi cua nhieu lodi thtfc vat khdc ngodi cay
Trau bd tr^ng nhdm ndng caohi$u sud't cija bdi Ipc nglm.
- Nghien ctfu khd ndng xtf Iy cua md hinh ddi vdi cdc chd't 6 nhiem khdc nhtf kim loai ndng,
cha'tgay mau...
- Nghien ctfu loai vdt li$u lpc cd khd ndng xtf 1^ tot hdn de stf dung cho be BASTAF vd bai
lpc ngam.
- Nghidn ctfu hieu sud't xtf Vj cua ttfng ngdn trong bd BASTAF.

- Nghien ctfu hieu su^t xtf Iy cua md hinh hdp khdi ddi vdi nhieu loai niTdc thdi khac nhau
nhtf: ntfdc thdi cua cdc chd khdc, ntfdc thdi sinh boat, nUde thai thiiy san, ntfdc thdi chdn nudi...

TAI U ^ U THAM KHAO
Tai U$u tham khao tieng Vi$t:
[1] Nguyin Viet Anh (2009), Betuhoai vd betuhoai cdi tii'n. NXB Xdy Dtfng, Ha Ndi, 156
trang.
[2] Leu Thp Bach, D.XanthouUs, Wang Chengduan, Hans Brix (2010),X^ly nude thdichi
phi thd'p, NXB Xay Dung, Ha Npi, 393 trang.
[3] Trufdng Thanh Canh (2009), Sinh hoa moi trudng, NXB Khoa Hpc Va Ky Thuat,
TPHCM, 263 trang.
Tai lieu tham khao tidng Anh:
[5] Brix, H, and Schierup, (1989), The use of aquatic macrophytes in water-pollution
control. Ambio 18
[6] Brix, H., (1993), Macrophyte-mediated oxygen transfer in wetlands: transport
mechanisms and rates.London,'pz%e'i9l-'i92>.
[7] Brix, H., (1997), Do macrophytes play a role in constructed treatment wetland?. SCi.
Tech, page 11-17.
[8] Mitsch, W.J. and Gosselink, J.G (1993), Wetlands. Van Nostrand Reinhold, Nev/ York.
[9] Hammer, D.A, (1992), Creating freshwater wetlands. Lewis PubHsher, Chelsea.
[10] Gumbricht, T., (1993), Nutrient removal processes in freshwater submersed
macrophyte systems, Eng.,page 1-30.
['^UMG^cs\f&EMc-GrawHill.