Nghiên cứu ảnh hưởng của nguồn carbon đến hiệu quả xử lý chất hữu cơ và nitơ trong nước thải bằng công nghệ SBR

TRUONG DAI HQC AN GIANG
KHOA KY THU^T - CONG NGHE - MOI TRU"CfNG

NGUYEN NGQC HO

NGHIEN CU"U ANH HlTOfNG CUA NGUON CARBON
DEN HIEU QUA Xf LY CHAT HUU CO VA NITO
TRONG NI/6C THAI BANG CONG NGHE SBR
TRUdNG DAI HOC!
AN GIANG

THl/VIEN
KHOA LUAN T6T NGHIEP

GVHD: Th.s NGUYEN THANH HUNG

An Giang, 04/2013


Khoa lute t6t nghiepDH10MT

LOflCAMON

Be co duqc thanh qua h6m nay em xin bai t6 long bilt on sau sic d^n quy
thiy c6 tnrbng Bai hoc An Giang, dac biet la cac thiy co trong khoa Ky thuat Cong nghS - M6i truong da t^n tlnh giang day, truyln dat, trang bi cho em nhung
kien there quj^ bdu trong su6t qua trlnh hoc tap.
Bac biet, em xin gtri lflri cam on chan thanh va sau sac den thay Ths.
Nguyen Thanh Hung, ngubi da tan tdm giilp d& hudng din em trong suit then
gian em thtrc hien dl tai khoa ludn nay
Em xin chdn thanh cam on den gia dinh, ban b^ va nhting ngucri than da
luon dong vien em trong suot qud trlnh hoc tSp cling nhu trong thbi gian there

hien dl tai khoa ludn t6t nghiep.
BS co duoc ngay horn nay, con xin gui loi c^m cm chan thanh nhlt din
ding sinh thanh da duong due va day d con nen ngubi, luon kl vai sdt canh bn
con, dfing vien nhung luc con ghp kho khan, luon day con nhting dilu hay I^ ph^i
cua cube sing dl con ngay mot hoan thien ban than horn.

Sinh vien thirc hien

Nguyln Ngoc H8

GVHB: Ths Nguyen Thanh Htag
S VTH: Nguyln Ngoc H6


Kh6alu^nt6tnghiSpDH10MT

NHAN XET CUA GIAO VIEN E0LT6NG DAN

Long Xuyen, ngaythangnam 2013

Giao vien hmfrig dan

Ths. Nguyln Thanh Hung

GVHD: Ths Nguyen Thanh Hung
SVTH: Nguyln Ngoc H6
.


Khoa luto t6t nghiepDH10MT

NHAN XET CUA GIAO VIEN PHAN BIEN

Long Xuygn, ngay. ^^.. thang. .<(Cnam 2013
Giao vien phan bien

'Jiu.ru Th^nh.

GVHD: Ths Nguyen Thanh Hungiii
SVTH: Nguyln Ngoc H6


Khoalu^ntdtnghiepDH10MT

NHAN XET CUA GIAO VIEN PHAN BIEN

Long Xuyen, ng^ythangnSm2013
Gi^o vien phan bifn

GVHD: Ths Nguyln Thanh Hhngiv
SVTH:NguylnNgocH6


Kh6a Man t6t nghiepDH10MT

TOM TAT

DS tii khda luan: "Nghien cihi tilth hie&ng ciia nguon carbon den hieu
qua xfc /j^ chit hieu cat vh Nitot trong nie&c thai bang cdng nghi SBR" duoc
thuc Men tren mo Mnh nghien ciiu SBR vdi 5 qua trinh ky khf, hieu khi, thieu

khl, hieu khi, thieu khi xen ke nhau. Theo kt qua phan tich qua c4c qua trinh xii
1^ (COD, N-NIh(+, N-NO3") trong 3 loai nude thai co ngudn carbon ttr glucose,
acetate, 50% glucose + 50% acetate tren mo hlnh SBR nghien cmi nhu sau:
•Hieu qua xu ly chat hun co trong nude thai tuong ung vdi nguon
carbon tu glucose, acetate v^ 50% glucose + 50% acetate Ian Mot la
93.04

1.1%, 88.67

1.07% va 96.6

1.76%.

•Hieu qua xu ly ammonium trong nude thai tuong ung vdi nguOn
carbon tir glucose, acetate va 50% glucose + 50% acetate lin Mot la 93
1.41%, 69.08

12.09% va 76.9 6.02%.

•Hieu qua xu ly nitrat trong nude thai tuong ung vdi nguon carbon tu
glucose, acetate va 50% glucose + 50% acetate Ian Mot la 60.5
4.83%, 52.6

8.19% va 58.6

5.59%.

Vdi k6t qua van hanh va phan tich c4c chi tieu COD, N-NH4+, N-NO3"
trong 3 loai nude thai tren m6 Mnh SBR nghien eta, cd thg thly cong nghe SBR
la mot he thdng lmh (Jong v^ cd hieu qua xu 1^ chat 6 nhilm cao.

GVHD: Ths Nguyln Thanh Hung
SVTH:Nguy&NgocH6


Khoa luan t6t nghigpDH10MT

ABSTRACT
Thesis topic: "Studying on the effects of carbon sources to processing
efficiency organic substance and nitrogen in wastewater by SBR technology" is
made in the research of SBR model with five processes anaerobic, aerobic,
anoxic, aerobic, anoxic interlaces together. According to the analysis results of
the process (COD, N-NH4+, N-NO3") in three kinds of wastewater carbon source
from glucose, acetate, 50% glucose + 50% acetate on SBR model are:

•Efficient processing of organic substance in the wastewater has carbon
source from glucose, acetate and 50% glucose + 50% acetate respectively 93.04
1.1%, 88.67% and 96.6

1:07

1.76%.

•• Efficient processing of ammonium in wastewater has carbon source from

glucose, glucose + acetate and 50% respectively 50% acetate 93% 1:41, 12:09
69.08% and 76.9% 6:02.
•Efficient processing nitrate in wastewater has carbon source from
glucose, acetate and 50% glucose + 50% acetate respectively 60.5

4.83%, 52.6

8.19% and 58.6 5.59%.
As a result of the operation and analysis of targets COD, N-NEU"1", N-NO3"

three types of wastewater model SBR researchers can see that technology SBR
is a flexible system and efficiently handle quality pollution.

GVHD: Ths Nguyln Thanh Hung
SVTH: Nguyln Ngoc H6


Kh6a luan t6t nghiepDH10MT

MUC LUC
Chirong 1: GlOl TfflEU1
l.l.BatvdndS,1

1.2.Muc tieu nghien ciiu2
1.3.Pham viva d6i tuong nghien ciiu2
1.4.Thai gian v^ dia diem nghien cdu2
1.5.Noi dung nghien cuu2
1.6.Y nghia cua de thi3
1.6.1.Tinhkhoahoccuad6thi3
1.6.2. Tinh thuc tiln cua &h tai3

Chirong 2: TONG QUAN4
2.1.Tong quan v6 cong nghe SBR4
2.1.1.Giaithieu4
2.1.2.Nguyen t^c qud trhih hoat d6ng cua SBR4

2.1.3.Qua trinh ling dung cua SBR6
2.1.4.C^c ling dung xu ly nuac thai sinh hoat d6 thi7
2.1.5.Uhg dung cong nghifp7
2.2.Khai quat vb phuong phip xu ly nita7
2.2.1.Trang thdi t6n tai cua nita trong nude thai7
2.2.2.Xft ly hop chit nita10
2.3.Cdc qu^ trlnh sinh hoc dien ra trong be SBR13
2.3.1.Qua trinh phan My hi^u khi ca chit ddu vao va nitrat hoa13
2.3.2.Quh trinh khu nitrat hoa (denitritfication) trong bb14
2.4.Cac nghien ciiu vexu ly Ioaib6 nito trong nuac thai16

Chuong 3: NOI DUNG VA PHUONG PHAP NGHIEN CUU19
3.1. Thanh phan nude thai19

GVHD: Ths Nguyln Thanh Hungvii
SVTH: Nguyln Ngoc H6


KhdaluantitnghiepDH10MT
3.2.Mo hlnh nghi&i ciiu20
3.2.1.Ciutaom6hlnh20
3.2.2.V^n hanh m6 hlnh nghien ciiu21
3.3.Phuong phdp phan tich mau23

Chmmg 4: KET QUA THAO LU^N24
4.1.Anh hudng cua ngu6n carbon din hieu qua xu ly chat 6 nhiem24
4.1.1.Nguin carbon anh hubng dSn hieu qua xu ly chit huu co24
4.1.2.Ngu6n carbon anh hu&ng din hieu qua xu ly ammonium (N-NH4"1^

25

4.1.3.Nguon carbon anhhubng den hieu qua xu ly Nitrat (N-NO3")25
4.2.Qua trinh xu ly chit 6 nhiim tren timg loai nude thai co nguin carbon
khaenhau25
4.2.1. Qua trinh xii ly (COD, N-NH4+, N-NO3") trong nude thai co ngudn

carbon tir glucose25
4.2-2. Nghien chu hieu qua xu ly nude thai co nguon carbon la acetate... 28

4.2.3. Nghien cdu hieu qua xu ly nude thai co nguon carbon la 50%
glucose + 50% acetate31

Chuong 5: KET LUAN VA KIEN NGHI36
5.1.K6tluan!36
5.2. Kiinnghi36

PHULUC38
TAI LIEU THAM KHAO49

GVHD: Ths Nguy6n Thanh Hung
SVTH: Nguyln Ngoc H6


Khda luan t6t nghidpDHiOMT

DANH SACH BANG

Bang 1: C&c chl tieu trung binh c^c hop chat Nito trong nude thai sinh hoat9
Bang 2: Ghi mot s6 dac trung cua c^c he thdng sinh hoc dung dg xil ly nude thai
gi^u hop chat nita12
Bang 3: Th^nh pMn nude thai nude thai nghien ciiu19

Bang 4: Cac phuong ph&p phfln tich mau23
Bang 5: C&c thong s6 chi tieu N-NH4+ cua nude thai vdi ngudn carbon ttr
Ghicose38
Bang 6: Cac thong sd chi tieu N-NH4+ ciia nude thai vdi ngudn carbon trr
Acetate,38
Bang 7: C^c thong s6 chi tieu N-NH4+ cua nude thai vdi ngudn carbon tit 50%
Glucose + 50% Acetate39
Bang 8: Cdc thdng sd chi tieu COD cua nude thai vdi nguon carbon tit Glucose40
Bang 9: Cac thong so chi tieu COD cua nude thai vdi ngudn carbon ttr Acetate40
Bang 10: Cac thong s6 chi tieu COD cua nude thai vdi ngudn carbon ttr 50%
Glucose + 50% Acetate41
Bang 11: Cac thdng sd chi tieu N-NO3- cua nude thai vdi ngudn carbon ttr
Glucose42
Bang 12: Cac thdng sd chi tieu N-NO3" cua nude thai vdi ngudn carbon ttr
Acetate42
Bang 13: Cac thdng sd chi tieu N-NO3" ciia nude thai vdi ngudn carbon ttr 50%
Glucose + 50% Acetate43
Bang 14: Hieu sudtxu ly nude thai cd ngudn carbon ttr Glucose44
B^ng 15: Hieu suat xtr ^^ nude th^i cd ngudn carbon ttr Acetate44
Bang 16: Hieu suit xu ^^ nude thai cd ngudn carbon ttr 50% Glucose + 50%
Acetate45

GVHD: Ths Nguydn Thanh Himg
SVTH: Nguy8n Ngoc Hd


KhdaluantdtnghiepDH10MT

DANH SACH HINH

Hinh 1: Cac giai doanhoat ddng5
Hinh 2: Chu trinh nito trong tur nhien8
Hinh 3: Qua trinh chuy^i hda Nita14
Hinh 4: Qua trinh chuyen h6a Nita trong nude15
Hinh 5: Mo hinh bd SBR lam viec theo me20

Hinh6:MdhlnhbgSBRthuctg21
Hinh 7: Chu ^^ hoat dpng ciia bg SBR22
Hinh 8: Hieu suit xii ly COD, N-NH4+ va N-NO3" ciia 3 loai nude thai

24

Hinh 9: Qud trinh xu ly COD trgn md hinh SBR nghign ciiu ciia nude thai cd
ngudn carbon tur glucose26
Hinh 10: Qua trinh xu ly N-NH4+tren mo hinh SBR nghign cuu ciia nude thai cd
ngudn carbon tir glucose27
Hinh 11: Qua trinh xii ly N-NO3" trgn md hinh SBR nghign cuu cua nude thai cd
ngudn carbon ttr glucose28
Hinh 12: Qud trinh xu ly COD tren md hinh SBR nghidn ciiu cua nude thai cd
ngudn carbon tir acetate29

Hinh 13: Qua trinh xu ly N-NH4+tren md hinh SBR nghien cuu ciia nude thai cd
ngudn carbon tir acetate30
Hinh 14: Qua trinh xu ly N-NO3" tren md hinh SBR nghidn ciiu ciia nude thai cd
ngudn carbon ttr acetate31
Hinh 15: Qua trinh xu ly COD trgn md hinh SBR nghign ciiu cua nude thai cd
ngudn carbon ttr 50% glucose + 50% acetate32
Hinh 16: Qua trinh xii ly N-NH4+tren md hinh SBR nghien ciiu ciia nude thai cd
ngudn carbon tir 50% glucose + 50% acetate33
Hinh 17: Qud trinh xu ly N-NO3" tren md hinh SBR nghien ciiu cua nude thai cd

ngudn carbon tir 50% glucose + 50% acetate34

Hinh 18: Md hinh SBR hoanchinh46
Hinh 19: Md hinh Md hinh SBR ban ddu (mdi rap)46
Hinh 20: Md hinh luc mdi bat dau tha bun...47

GVHD: Ths Nguyln Thanh Hiingx
SVTH:NguygnNgpcHd


Khoa Man t6t nghiepDH10MT
fflnh 21: Mo Mnh Me ton 15ng47
Hrah22:M6Mnhbundathichnghi48
Hinh23:Mayth6ikhi48

GVHD: Ths Nguyln Thanh Hungxi
SVTH: Nguyln Ngoc H6


Khoa luan t6t nghiepDH10MT

DANH MUC TIT VIET TAT

BODNhu clu oxy sinh hoa
CODNhu ciu oxy hoa hoc
SBRSequencing Batch Reactor
DOOxy h6a tan
TSSTong ran la lung
1 bsCODCOD hoa tan phan huy shih hoc
PAOsVi sinh vat tlch luy photpho

VSVVi sinh v^t
PHBPolyhydroxylbutyrate
AOBVi khuin oxy hoa ammonia (Ammonia Oxidizing Bacteria)
NOBVi khuan oxy h6a nitrit (Nitrite Oxidizing Bacteria)
TCETrichloroethylene

QCVNQuy chuin Viet Nam
VSBBe phan ung sinh hoc thang
E-SBRQua trinh trao d6i ion SBR
DPAOs

Vi sinh v^t tich luy photpho khii nita (Denitrifying Phosphorus

Accumulating Organism)

GVHD: Ths Nguy^n Thanh Hung
SVTH: Nguy^n Ngpc Ho


Khda luan t6t nghiep;DH10MT

Chirang 1

Gl6l THIEU
1.1. DatvSndg

Do thi hoa, cong nghiep hoa nhu la don bay cho sir tang truang cac nganh
kinh te, phat trien xa hoi va nang cao mire song cua nhan dan. Dong thai cong

nghiep hoa, hien dai hoa dat nude tao nen mot sue ep ldn doi vdi moi trubng va
con ngudi. Chung lam suy giam chSt luang moi truang, lam miit sir can b^ng
sinh thai va lam suy thoai tai nguyen thien nhien. Thuc trang 6 nhiem moi truang
cong nghiep a nude ta ngay cang trd nen bde xuc do sir phat trien vdi toe dp cao
cua cac hoat dpng san xuat cong nghiep ca ve so luang ca sd va qui mo san xuat.

Su phat trien nhanh cua cac nganh cong nghiep la mot trong nhung nguyen nhan
quan trpng dan den van de o nhiem moi trudng nuac ma chung ta dang phai doi
mat.

Hien nay, nude thai mot so nganh cong nghiep nhu ruau bia, cao su, thuy
san ...cd ham luong chat dinh duang, chat hfru ca cao nhung chua dupe xir ly

triet de trudc khi thai ra moi trudng. Dieu nay se tao moi trudng thuan lai cho
mot so loai tao va vi khuan cd ca hoi phat trien nhanh lam cho luang oxy hoa tan
trong ngudn nude bi sut giam, mui hoi mat my quan, gay hai den thuy sinh dpng
thuc vat d nguon tiep nhan. De gan van de phat trien cong nghiep di doi vdi bao
ye Moi trudng doi hoi cac ca sd san xuat, nha may phai dau tu xay dimg he
thong xd ly nude thai dat yeu cau theo quy chuan nham giam tdc hai den moi
trudng d muc thap nhat. Vdi nude thai sinh hoat san xuat ngoai viec xir ly loai bd
chat huu ca van de loai chat dinh dudng la mot yeu cau ma cac cong trinh xu ly
cfin phai quan tarn. Hien nay QCVN 14:2008/BTNMT yeu c^u kha kbit khe vg
thanh phan nita va photpho dau ra sau xu ly. Chinh vi vay viec nghien cdu, xay
dung he thong xu ly nude th^^i dam bao yeu cgu va chi phi xur ly thap la van dg
dupe dua ra cho cac nha nghign cdu.

Dg tai "Nghien ciiu dull hiefing cua nguon carbon den hieu qua xir ly
chat huu eff va Niter trong nu&c thai bang cong nghe SBR" dupe thuc hien
nham lam ca sd dg danh gia anh hudng thanh phan chat huu ca dgn hieu qua xu
ly chat huu ca, nita trong nude thai. Nghign cdu dupe thuc hien trgn mo hinh xu

ly nude thai blng cong nghe SBR vdi cac qua trinh ky khi, thigu khi va higu khi
xen ke nhau dg xd ly chat huu ca, nita trong nude thai. Day la dang cong trinh xu
ly nude thai bang qua trinh sinh trudng la lung higu khi, dac bigt hai giai doan
sue khi va king diln ra trong cung mot bg. Cong nghe SBR da chung to dupe la
mot cong nghe xd ly cd nhigu uu digm. He thong linh dpng cd thg xd ly nhigu

GVHD: Ths NguyIn Thanh Hung1
SVTH:NguygnNgpcH6


Khoa luan tdt nghiepDH10MT

loai nude thai khac nhau vdi nhieu thanh phan, nhieu tai trong, dieu khien hoan
toan tir dong, hieu qua xur ly 6 nhiem cao, qua trinh lang d trang thai tinh nen
hieu qua lang cao.
1.2.Muc tieu nghien ciiu

Nghien ciiu anh hudng cua nguon carbon trong nude thai den hieu qua xu
ly COD va Nita bdng cong nghe SBR.
1.3.Pham vi va doi tirung nghien ciiu
a. Pham vi nghien ciiu

Nghien ciiu diroc thuc hien d quy mo phong thi nghiem. Qua trinh van
hanh mo hinh va phan tich cac thong so dugc thuc hien tai phong thi nghiem Moi
trudng - Khu thi nghiem Trung tarn, Truong Dai hoc An Giang.
h. Doi tirong nghien ciiu
Nude thai nghien ciiu cho mo hinh la nude thai nhan tao, vdi thahh phan
carbon khac nhau trong 3 loai nude thai (3 thanh phan khac nhau chu yeu la:
glucose, acetate va 50% glucose + 50% acetate). Thanh phan N-NH4+ va cac vi

lucmg can thiet khac trong nude thai khong thay doi trong 3 loai nude thai nghien
ciiu. Nude thai nhan tao vdi thanh phSn COD/N/P tuong ling 100/5/1.
1.4.Thoi gian va dia diem nghien ciiu
-Thai gian: Tu thang 02 dSn thang 04 nam 2013
-Dia diem: Mo hinh thi nghiem dugc bo tri tai phong thi nghiem Moi
truong - Khu thi nghiem Trung tam , Trudng Dai hoc An Giang
1.5.Noi dung nghien ciiu

Nghien ciiu hieu qua xu ly COD vdi nguon carbon khac nhau tren tirng
loai nude thai bang cong nghe SBR
Nghien ciiu qua trinh xu ly COD qua tiing giai doan tren be SBR doi vdi
tung loai nude thai cd nguon carbon khac nhau.

Nghien ciiu hieu qua nitrat hoa va khu nitrat b3ng cong nghe SBR vdi
tiing loai nude thai cd nguon carbon khac nhau trong nude thai.

GVHD: Ths Nguyin Thanh Hung
SVTH: Nguy6n Ngoc H6


Khda luan t6t nghiepDH10MT
1.6. Y nghia cua de tai
1.6.1.Tinh khoa hoc cua dg tai

Binh hudng nghien ciiu phu hop va co ca sd khoa hoc trong viec lira chon
mo hinh be phan ling theo me de xii ly nude thai giau thanh phan chat huu co va
dinh duong.
Nghien ciiu duqc tien hanh theo trinh tir he thong cua qua trinh van hanh
va xii ly nude thai. Bat dau tir giai doan thich nghi hoat dong ciia mo hinh cho
den qua trinh thay doi thanh phan chat nude thai nghien ciiu.

Toan bo ket qua cua khoa luan duqc thu thap tir qua trinh nghien ciiu thtrc
nghiem cu the, co can cii khoa hoc ro rang. Viec tinh toan, xii ly so lieu thong
qua cac phuomg phap thong ke toan hoc tren phan mem Excel. Cac hinh anh,

bang bieu de lai nhung thong tin co ich cho cac nghien ciiu sau.
1.6.2.Tinh thuc tiln cua dl tai
Ket qua nghien ciiu cung cap cac thong so dang tin cay ve che do van

hanh phu hop cho mot he thong SBR khii nito. Tir do phat trien nghien ciiu tir
quy mo phong thi nghiem len quy mo thuc te nham: nang cao hieu qua xii ly nito
trong nude thai, han che nganngira trinh trang 6 nhiem nguon nuoc. Ben canh

do, ling dung cong nghe nay vao cac qua trinh xir ly tren cac lo^.i nude thai tuong
tu cd thanh phan 6 nhiem huu co va chat dinh duong cao.

GVHD: Ths Nguyln Thanh Himg
SVTH:NguylnNgocH6


Khda Man t6t nghiepDH10MT
Chuvng 2

t6ng quan
2.1. T6ng quan vl cong nghe SBR
2.1.1.Gidithieu
SBR {Sequencing Batch Reactor) la cong trinh xu ly sinh hoc nude thai
bang him hoat tinh dang me. He thong SBR dupe tim ra va nghien cfa tir nhung
nam dau cua the ky XX va Men nay co nhieu nghien ciiu thanh cong khi su dung
he thong nay de xu ly cac loai nude thai chiia chat dinh dufag. Tu nhitng nam
dau thap Men 80, Sutton da fag dung thanh cong SBR cho qua trinh xu ly nude

ri rac (1988). Kl tir do, nhilu nghien cfa vl he thing nay da va vSn dang dupe
tilp Me thuc Men. T6 chuc U.S EPA cua My da xac dinh cong nghe SBR la mot
trong cac cong nghe dupe lira chpn hang dlu trong chuong trinh "Banh gia cong
nghe co tinh thay the va cai tien" (IATA program - " Innovative and Alternative
Technology Assessment Program^).
(Nguon: A. Brown & et al, 2005) .

SBR thuc chat la mot he thong bun hoat tinh lam viec theo me Man phien
noi tiep nhau. Bay la qua trinh bun hoat tinh van thufag rat dupe ua chuong su
dung de xu ly nude thai sinh hoat. Qua trinh gom 5 giai doan: cho nude vao,
phan fag (ky khi, hieu khi, thigu khi), ling, thao nude ra, chd nap me mdi dupe
thuc hien trong cung mot be phan fag, do do rat tiet kiem dien tich xay dung.
Trong he thong SBR bun hoat tinh khong can Man hoan de duy tri nong dp bun
trong be nhu cac qua trinh bun hoat tinh khac. SBR hieu qua cao khi xd ly nude
thai sinh hoat va nude thai cong nghiep co nong dp chat huu ca hoa tan va chat
dinh duong cao.
{Nguon: Lawrence K. Wang, 2009)

Noi chung, cong nghe SBR da chfag to dupe la cong nghe xu ly co hieu
qua cao, trong qua trinh su dung it ton nang lupng, de dang kiem soat cac sir co

xay ra, it ton dien tich rat phu hop vdi nhung tram co cong suat nho. Ngoai ra,
cong nghe SBR co the xu ly nude thai co ham lupng chat hfa ca va chat dinh
duang cao.

2.1.2.Nguyen tic qua trinh hoat dong cua SBR
Qua trinh SBR truy^n thdng hoat dong tren nguyen tic lam diy va thao
nude ra. Thong thufag, qua trinh gom cac budc ca ban lam day, phan fag, lang
va thao nude. Thuc te thai gian chu ky se khac nhau vdi yeu cau dong thai khac
nhau. Neu chi yeu cau khii BOB thi thai gian chu ky co thd dupe su dung la 3

GVHB: Ths Nguyln Thanh Hung4
SVTH: Nguyln Ngpc H6


DH10MT

Khoa luan tot nghiep

gib. Neu yeu cau tiep tuc xu ly de kiem soat chat dinh duang, thi thai gian chu
ky co the dupe md rpng de dap tag yeu cau hieu qua xu ly.
A. Cdc giai doan hoat dong

4 Settle
Hinh 1: Cdc giai doan hoat dong

•k Pha lam dhy (Fill/Filling stage): Co thi van hanh vdi 3 chi dp lam diy
tTnh, lam day hoa trpn va lam day sue khi nham tao moi trutag khac nhau
cho cac muc dich khac nhau. Thai gian pha lam day co the chiem tu 25 30%.
ik Pha phan ieng/suc khi (React/ Mixing Stage): Ngung dua nude thai vao.
Tien hanh sue khi. Hoan thanh cac phan tag sinh hoa co thi dupe bit dau
tu pha phan tag. Thai gian phan tag chiem khoang 30% chu ky hoat
dong.

afe Pha Idng (Clarification/Settling Stage). Dieu kien tinh hoan toan dupe
thuc hien (khong cho nude thai vao, khong nit nude ra, cac thiet bi deu
tat) nham tao diiu kien cho qua trinh ling. Thai gian tinh chiim khoang tu
5 - 30% thai gian chu ky hoat dong.
i Pha thdo ntt&c sach (Decant/Drainage). Thao nude sau xii ly ra khdi be

SBR
k Pha chit (Idling Stage): Ap dung trong mot si bi phan tag, co the bo qua
trong mot si thiit ki.
Thai gian hoat dong co thi tinh sao cho thich hop vdi tung loai nude thai
va muc tieu xii ly khac nhau. N6ng dp bun trong bi thutag khoang tur 1500 -

GVHD: Ths Nguyln Thanh Hung5
SVTH: Nguyln Ngpc H6


Khoa luan t6t nghiepDH10MT

2500 mg/1. Chu ky hoat dong cua be dupe dieu khien bang he thong role thai
gian. Trong be co the bo tri he thong vat vang, thiet bi do mure bun. Tren thuc te

SBR co th co thai gian chu ky la 6 gia d&i 48 gia.
2.1.3. Qua trinh u-ng dung cua SBR

Cong nghe SBR truyen thong cho phep xii ly chat him ca, bao gom loai bo
hoac bien doi chat dinh duong, tat ca cac qua trinh xir ly cua SBR xay ra trong
pham quy cua be xii ly.
a.XirlyBOD
Viec loai bo cac chat hiru ca xay ra trong suot qua trinh hoat dong cua be
SBR.
Hdu h^t cac vi khuln trong b^ phan ling t&n tai trong tu nhien. Chung se
loai bo chfit htm ca a giai doan ky khi khi khong co mat oxy (giai doan lam day)
va hieu khi khi co mat oxy (giai doan phan ling). Yeu cau oxy dirac tinh gia dinh
chi loai bo hieu khi cua chat him ca. Ben vi chi mot phan cua chu trinh dugc danh
cho sue khi, nhu cau oxy phai thoa man trong khoang thai gian nay. Thai gian
chu ky can thiet cho loai bo chat him ca chi it han cho hoat dong loai bo chat

dinh durang.

(Ngudn: Metcalf& Eddy, 2003)
b. XulyNita
Oxy hoa ammonium thanh nitrat (nitrification) bao gom hai birac sau: dau
tien chuyen hoa ammonium thanh nitrite va sau do thanh nitrat, Cac vi khuan
chiu trach nhiem chuyln hoa nay la nitrosomonas, nitrobacter va hoat dong trong
dieu kien hieu khi, yeu cau oxy la khoang 4,6 g oxy cho moi gam cua ammonium
nitrogen bi nitrat hoa.
Trong su vang mat cua oxy hoa tan (DO), mot so vi khuan tuy tien thuang
hien dien trong he th6ng xix ly nuac thai co thl sir dung nitrat nhu la mot chat
nhan dien tur cuoi ket qua hinh thanh khi nita (qua trinh denitrification). Chat cho
dien hi (nguon nang lugng carbon) thuang dugc hien dien nhu mot nguon carbon
tu nhien trong nuac thai trong mot bS SBR.
Cac diSu kien cho cac qua trinh nitrat hoa la du DO va dp kiem, cpng vai
mot nguon carbon. KM: nitrat doi hoi dieu kien DO phai gan bang khong, mot
nguon carbon, va nitrat. Ngoai ra, cac dieu kien trong be phan ung phai dupe

thich hop cho viec duy tri cac vi khuin nitrat hoa va khii nitrat hoa.

GVHD: Ths Nguyln Thanh Hung

SVTH: Nguyln Ngpc H6


Khda luan t6t nghiepDH10MT
Be dam bao su phat trien cua sinh vat nitrat hoa can co du thai gian luu
bun cua he thong va dam bao du lugng oxy hoa tan. Giai doan thieu khi trong
chu ky SBR la giai doan khur nitrat (chuyen hoa nitrat thanh khi nita).
2.1.4.Cac ling dung xfr ly nude thai sinh hoat do thi

He thong SBR hien dang dugc sii dung trong nhieu tinh huong xu ly khac
nhau, theo mot loat cac dieu kien tai. Qua trinh SBR co the dugc sii dung de xu
ly cho bat ky nude thai ma co the xu ly bang he thong bun hoat tinh, bao gom: he
thong anoxic/oxic, ao sue khi hay he thong sue khi dugc mo rpng, be lpc sinh
hoc, cac he thong mang sinh hoc va muong oxy hoa.

Bdi vi SBR co hieu qua xu ly cao cho khii BOD/COD, TSS, nita va
photpho, no dugc su dung rgng rai cho xii ly nude thai tir cac do thi, casino, khu
nghiduang...

(Ngudn: NguySn Van Phuac, 2006)
2.1.5.Ung dung cong nghiep

SBR da dugc ap dung thanh cong de xii ly nude thai cong nghiep sau day:
-Hoa chat va hoa dau
-Nude ri rac
-Thudcla
-Thucpham

-Bot giay va giay
-Sua

-Bo uong
-Bet

-Xudngthupcda
-OCPSF (chat huu ca, nhua, chSt tfing hgp va sgi)
-Nita cao

-Bat ky nude thai khac co the xu ly sinh hoc dugc.

(Ngudn: Nguyin Van Phuac, 2006)
2.2. Khai quat ve phuong phap xii ly nito'
2.2.1. Trang thai ton tai cua nito' trong nude thai

Theo TrSn Buc Ha, B6 Van Hai, 2002 trong nude thai, cac hop chit ciia
nita ton tai dudi 3 dang: cac hop chat huu ca, amoni va cac hgp chat dang oxy
hoa (nitrit va nitrat). Cac hop chat nita la cac chat dinh dudng, chiing luon van
dpng trong tu nhien, chu yeu nhd cac qua trinh sinh hoa.

GVHB: Ths Nguyin Thanh Hung7
SVTH: Nguyin NgpcHd


DH10MT

Khda luan tdt nghiep

Nito phan td N2
Co dinh nito
N-protein dong vat

N-protein thuc vat

^vmdnnoa
. NH,+ hoac NH3

Khii nitrat
Nitrat hoa
NO,

NO,

+ O2
Hinh 2 : Chu trinh Nito trong tie hhien

Hop chat hfru co chua nito la mot phan cau thanh phan hi protein hoac la
thanh phan phan hiiy protein nhu la cac peptid, axit amin, ure.
Ham lirong amoniac (NH3) chinh la lrrpng ammonium (NH/) trong nude
thai sinh hoat, nude thai cong nghiep thirc pham va mot so loai nude thai khac cd
the rat cao. Cac tac nhan gay 6 nhiem nito trong nude thai cong nghiep: che bien
sua, rau qua, do hop, che bien thit, san xuat bia, ruou, thuoc gia.

Trong nude thai sinh hoat nito tdn tai dudi d^ng vo co (65%) va huu co
(35%). Nguon nito chu yeu la tir nude tieu. Moi ngudi trong ngay xa vao he
thong thoat nude 1,2 lit nude tieu, tuong duong vdi 12g nito tong so. Trong so do
nito ure (N-CO(NH2)2) la 0,7g, con lai la cac loai nito khac. Ure thudng duoc
amoni hoa theo phuong trinh nhu sau.
Trong mang ludi thoat nude ure thuy phan:

CO(NH2)2 + 2H2O = (NH4)2CO3
Sau do bi thoi rua:
(NH4)2CO3 = 2NH3 + CO2 +H2O
Nhu vay NH3 chinh la luong nito amon trong nude thai. Trong dieu kien
yern khi amoniac cung cd thd hinh thanh tu nitrat do cac qua trinh khu nitrat cua
vi khuan Denitrificans.

Luqng chat ban Ammonium (N-NH4+) mot ngudi trong ngay xa vao he
thong thoat nude: 7 g/ng.ngay
Trong thanh phan nude sinh hoat thai khu dan cu:

GVHD: Ths Nguyen Thanh Hung

SVTH: Nguyin Ngpc H6


Khda luan tdt nghiepDH10MT

Bang 1: Cdc chi tieu trung blnh cdc hap chat Nita trong nuac thai sink hoat
Chi tieu

Trung binh

40

Tdng niter, mg/1
- Nita htiu ca, mg/1

15

-

25

Nita amoni, mg/1

- Nita nitrit, mg/1

0,05

- Nita nitrat, mg/1

0,2

Tong photpho, mg/1

8

Nitrit (NO2~) la san pham trung gian cua qua trinh oxy hoa amoniac hoac
ammonium trong dieu kien hieu khi nhd cac vi khuan Nitrosomonas. Sau do
nitrit hinh thanh tidp tuc duac vi khuln Nitrobaeter oxy hoa thanh nitrat.
Cac qua trinh nitrit va nitrat hoa dien ra theo phan ling bac I:
NH4+ -^. NO^ -^> NO3"
Trong do: kn va km la cac hang so toe do nitrit va nitrat hoa.

Cac phuang trinh phan ling cua qua trinh nitrit va nitrat hoa dupe bieu
dien nhu sau:

NH4+ + 1,5 O2
NO2" + 0,5O2

Nitrsom"% NO2- + H2O + 2H+
MfrotoeS NO3"

NH4+ + 2O2

> NO3" + H2O + 2H+

Qua trinh nitrat hoa can 4,57g oxy cho lg ammonium. Cac loai vi khuln
Nitrosomonas va Nitrobaeter la cac vi khufin hi^u khi thich hop vdi di^u kien
nhietdotu20^30oC.

Nitrit la hop chit khong bin, no cung co thi la san phim cua qua trinh khii
nitrat trong diiu kien yim khi.
Ngoai ra, nitrit con co nguon goc tir nuac thai qua trinh cong nghiep dien
hoa. Trong trang thai can bang d moi trudng nude, ndng do nitrit, nitrat thudng
rat thap, no thudng nhd han 0,02 mg/1. Neu ndng dp ammonium, gia tri pH va

GVHD: Ths Nguydn Thanh Hung9
S VTH: Nguyen Ngpc H6


Khda luan t6t nghiepDH10MT
nhiet dp cua nude cao, qua trinh nitrit hda dien ra thuan lpi, va ndng dp cua no co

the dat den gia tri Idn. Trong qua trinh xil ly nude, nitrit trong nude se tang len
dptngpt.
Nitrat (NO3") la dang hpp chat vo op cua nita co hoa tri cao nhat va co
ngudn gdc chinh tu nude thai sinh hoat hpac nude thai mot so nganh cong nghiep
thuc pham, hoa chat,... chua mot lupng ldn cac hop chat nita. Khi vao song"ho,

chung tiep tuc bi nitrat hoa, tao thanh nitrat.
Nitrat hoa la giai doan cudi cung cua qua trinh khoang hoa cac chat him
ca chiia nita.

Nitrat trong nude thai chiing to sir hoan thien cua cong trinh xu ly nude
thai bang phuang phap sinh hoc.
Mat khac, qua trinh nitrat hoa con tao nen sir tich luy oxy trong hop chat
nita de cho cac qua trinh oxy hoa sinh hda cac chat huu ca tiep theo, khi luang
oxy hoa tan trong nude rat it hoac het.

Khi thieu oxy va tdn tai nitrat hda se xay ra qua trinh ngupc lai: tach oxy

khdi nitrat va nitrit de su dung lai trong qua cac qua trinh oxy hda cac chat him
ca khac. Qua trinh nay dupe thuc hien nhd cac vi khuan phan nitrat hda (vi
khuan yem khi tuy tien). Trong dieu kien khong co oxy tu do ma moi trudng van
con chat him ca carbon, met so loai vi khuan khu nitrat dupe bieu dien theo
phuang trinh trinh phan ung sau day:
4NO3" + 4BT-+ 5C hauca

> 5CO2 + 2N2 +2H2O

Trong qua trinh phan nitrat hda, lg nita se giai phdng l,71g O2 (khu nitrit)
va 2,85g O2 (khu nitrat).
2.2.2. Xu ly hpp chat nita
Xu ly hop chat nita cd the thuc hien bang cac bien phap hda ly (hda hoc),
vat ly hoac sinh hoc dua tren cac nguyen tac chuyen hda thanh hpp chat khac
hoac tach loai, each ly chung ra khdi moi trudng nude.
- Chuyen hda cac hpp chat nita thanh dang khi, tham nhap vao khi quyen.
Con dudng chuyln hda nay cd thg thuc hien bdng phuang phap sinh hoc
thong qua ede qua trinh lien tigp nitrat hda (oxy hda ammonium) va khu
nitrat (khu nitrat vdi tu each la chfit oxy hda va chit httu ca carbon la chat
khu). Thuc hien phan ling oxy hda khu true tiep giua ammonium vdi nitrit
va nitrat bang phuang phap vi sinh (qua trinh Anamox). Oxy hda xuc tac
true tiep amoniac vdi clo hoat dpng (clo hda tai dilm dot bidn).
GVHD: Ths Nguyln ThanhHimglo'
SVTH: Nguyn NgocHd


Khda luan t6t nghiepDH10MT
-Chuyen hoa cac hap chat nita thanh cac thanh phan trong te bao cua sinh

khoi (thuc vat va vi sinh vat). Qua trinh chuyen hoa tren gan lien vdi cac

phan ung sinh hoa xay ra trong te bao dgng, thuc vat, trong qua trinh

quang hap cua thuc vdt hay (Jong hoa cua vi sinh vat. Qua trinh tren ton tai
trong tu nhien la ca sd cua phuang phap xu ly bang cac loai thuy thuc vat.
-Boc hai amoniac vao khi quyen, Phuang phap nay that ra la chuyen chat 6
nhiem tu: nude vao khong khi, sau (16 phan Ian lai hap thu trd lai vao moi
truang nuac a nhOng vi trf khac. Be thuc hien phuang phap tren, amoniac

phai ton tai a dang bay hai (trung hoa) va do do tan cua amoniac trong
nuac rat Ian nen de thuc day can phai sue khi vai lupng rat Ian va a nhiet
do cao.

-Tach amoniac ra khoi moi truang nude co thS thuc hien blng phuang
phap trao doi ion tren cationit. Cac loai nhira cationit co dp chpn lpc trao
doi thap doi vai amoni, dung lup^g trao doi dpng thap, bi canh tranh bai
cac ion khac co mat vai nong do cao nhu canxi, magie. Loai zeolite tu

nhien clinoptilolite co kha nang chon lpc cao doi vai amoni co the duac su
dung trong mot so truang hop. Nitrat cung la cau tu co dp chpn lpc trao

d6i ion thap hau h6t tren cac loai nhua t6ng hop. Tren thi truoug co mot s6
anionit dat thu danh cho trao d6i nitrat.
Su dung mot so loai mang thich hop: mang nano, mang tham thau nguac
hay dien tham tich cung tach dupe cac hop chat nita dong thai vai cac hop chat
khac.

Hieu qua xu ly va gia thanh cua timg phuang phap rat khac nhau va kha
nang su dung timg phuang phap con phu thupc vao nong dp cua chat nita
(amoni) trong nuac.

Theo A. Mulder, 2003 phu thupc vao nong dp ammonium trong nuac thai,
cac phuang phap sau co the lira chpn dua tren tieu chi ve gia thanh:
-N6ng dp amoni trong nude thai khong cao, nho han 100 mgN/1 nhtr trong
nude thai sinh hoat thi phuang phap vi sinh la thich hop.
-Nong dp amoni nam trong khoang 100 — 5000 mgN/1 nhu trong nude thai
tir qua trinh phan huy bun (vi sinh) thi phuang phap dupe cho la kha di
van la phuang phap vi sinh. Ket luan nay dupe dua ra sau rat nhieu cong
trinh nghien cuu sau sac va toan dien. Phuang phap boc hai hoac ket tua
dudi dang struvite cung la phuang an kha di song gia thanh khong thuan
lai.

GVHD: Ths Nguyen Thanh Hung11

SVTH:NguylnNgpcH6


Khoa luan tot nghiep

DH10MT

- Nude thai co nong do amoni cao, Ion hon 5000 mgN/1 co the xu ly theo
phuong phap hoa ly se thuan loi ca ve mat ky thuat va kinh te. Ba co he
thong cong nghiep duac xay dung de xur ly nuac thai chiia 1,5% NH3
bang phuong phap sue khi nong de hoc hai amoni va thu hoi NH3 tir pha
khi.

Cho tdi nay giai phap xur ly sinh hoc duac thtrc hien rong rai hon cac giai
phap khac.

Bang 2: Ghi mot so Sac tnmg cita cac he thong sinh hoc dung de xu ly nuac thai

gidu hap chat nita.
Hexuly

Tai Iirong

Nang

Tile

kgN/(ha.ngay)

luwng tieu

COD/N

thu

Sinh khfli

kg/kgN

Mien qua
xu-IyN

kWh/kgN
Bun hoat
tinh, nitrat
hoa, khir

200-700"

2.3 2)

3-6

1.0-1.2

>75

200-700"

1.7 2)

2-4

0.8-0.9

>75

> 200 - 700 "

0.9

0

Ao tao

15-30

0.1-1.0

6-7

10-15

23-78

Aobeo

3-4

<0.1

28

20-26

74-77

nitrat
thong
dung
Bun hoat
tinh, nitrat
hda, khir
tu nitit
Bun hoat
tinh, oxy
hda true
tiep giua

NH3

>75

va

NO2"

GVHD: Ths Nguyen Thanh Himg
SVTH: Nguyin Ngpc H6

12