CHNG 5

X ly nc thaibang vi sinh vat

TS. Le Quoc TuanCN. Pham Th Minh Thu

Khoa Moi trng va Tai nguyenai hoc Nong Lam TP. Ho Ch Minh

Nc thai la nguon goc gay nen o nhiemsong ho va bien

Nc thai gay nen cac loai dch benh lantruyen trong moi trng nc

X ly nc thai la viec ap dung cac quatrnh Sinh - Hoa - Ly nham lam giam cacchat gay o nhiem co trong nc

Viec x ly nc thai thng lien ket viviec cung cap nc sach

Gii thieu

SS oo nhiemnhiemSS giagia tangtang cacacc chachatt gaygay oo nhiemnhiem trongtrong nncc aaccbiebiett lala cacacc chachatt hhuu cc khokho phanphan huhuyy..ChaChatt gaygay oo nhiemnhiem ththngng totonn tataii dadangng rarann vavalolongng..NguoNguonn gaygay oo nhiemnhiem xuaxuatt phaphatt tt quaqua trtrnhnh sinhsinhhoahoatt, , sasann xuaxuatt, , cacacc bebenhnh vieviennTrongTrong nncc coco momott llngng llnn vi vi sinhsinh thamtham giagia xxlyly chachatt thathaii, , tuytuy nhiennhien coco raratt nhienhieuu vi vi sinhsinh vavatt gaygaybebenhnhCaCacc quaqua trtrnhnh sinhsinh hohocc xaxayy rara trongtrong nncc thathaiioongng vaivai trotro quanquan trotrongng trongtrong vieviecc phanphan huhuyy chachattthathaii. . SS mamatt cancan babangng trongtrong chuoichuoi sinhsinh thathaii moimoi trtrngngnncc sese gaygay nennen hiehienn ttngng oo nhiemnhiem

VoVongng tuatuann hoahoann nncc vava nncc thathaii

Khu x lync thai

Khu x ly nc cap

Ngis dung

Cac song, ho, nc ngam

Nc sachcha clo hoa

Nc sacha clo hoa

Ncban

ChaChatt thathaii

ChaChatt hhuu cc hohoaa tan, tan, chachatt rarann ll llngng, vi , vi sinhsinh vavatt((mamamm bebenhnh) ) vava momott soso cacacc thathanhnh phaphann khakhacc

NoNongng oo chatchat thathaii biebienn oongng theotheo ttngng ngangayy vavatheotheo mumuaa

TrongTrong nncc thathaii ieienn hhnhnh, 75% SS , 75% SS vava 40% 40% chachatthohoaa tan tan lala hhuu cc. .

ChaChatt vovo cc lala sodium, Ca, Mg, sodium, Ca, Mg, ClCl, SO, SO4422--, PO, PO4433--, , COCO33--, NO, NO33--, NH, NH44++ vava momott tt kimkim loaloaii nanangng..

BODBOD55 tt 200 200 600 mg/l. 600 mg/l.

CaCacc thongthong soso cucuaa maumau nncc thathaii sinhsinh hoahoattieienn hhnhnh

Thanh phan Nong o (mg/l)Tong chat ran 300 1200

Chat ran l lng 100 350

Tong carbon hu c 80 290

BOD5 110 400

COD 250 1000

Tong nitrogen 20 85

Ammonia (NH4+) 12 50

Nitrite (NO2-) 0

Nitrate (NO3-) 0

Tong phosphorus 4 - 15

ChChcc nangnang cucuaa cacacc hehe thothongng xxlyly nncc thathaii

Chc nang chnh cua cac he thong x ly ncthai sinh hoat la lam giam thanh phan hu ctoi a e o ra song va nc ven b ma khonggay nen s o nhiem dng chat

He thong x ly loai chat hu c l lng, giamthanh phan gay benh, loai nitrate, kim loainang va cac hoa chat nhan tao.

Chat lng nc a c x ly i vao nguontiep nhan phu thuoc vao the tch, tnh trangnguon tiep nhan va kha nang pha loang ncthai cua no, thng th 20 mg/l BOD5 : 30 mg/l SS va pha loang 8 lan.

Vi lng nc thai rat ln hang ngay oi hoimot quy mo rat ln cho viec x ly nhng oivi cong nghe sinh hoc th van e o se cgiai quyet mot cach hieu qua.

ChChcc nangnang cucuaa cacacc hehe thothongng xxlyly nncc thathaii

SS oo quyquy hoahoachch hehe thothongng XLNT XLNT sinhsinh hoahoattNc thai tcum dan c

X ly tai cho

Thu gomva cha

Thu gomva x ly

X ly

X ly mambenh

X ly

Be t hoai

Chat dinhdng, vi sinh lamphan bon

Thu gomluan

chuyen

He thongx ly

Ti tieuhoac thai ranguon tiep

nhan

X ly tap trung

QuyQuy trtrnhnh xx lylynncc thathaii

CaCacc giaigiai oaoann xx lyly nncc thathaiiTien x

lyX ly s

capX ly cap

IIX ly cap

III

Nc thai

Song chanrac

em cat

Lang scap

Bun scap

Oxy hoasinh hoc

Lang thcap

Bun

Thai / S dung

Phan huy k kh

Ao hieu kh

Loc sinh hoc

Bun hoat tnh

Ao sinh hoc

Chlore hoa

Loc cat

Tien xly

X ly scap

X ly capII

X ly capIII

Nc thai

Song chanrac

em cat

Lang scap

Bun scap

Oxy hoasinh hoc

Lang thcap

Bun

Thai / S dung

Phan huy k kh

Ao hieu kh

Loc sinh hoc

Bun hoat tnh

Ao sinh hoc

Chlore hoa

Loc cat

CaCacc giaigiai oaoann xx lyly nncc thathaii

X ly cap 1: cho phep lang t 1.5 2.5 gi e loai SS va lamgiam BOD5 t 40 60%.

X ly cap 2: nc thai t XLC1 cha 40-50% chat ran l lng. Trong giai oan nay cac qua trnh sinh hoc dien ra e loai thaichat hu c

Qua trnh k kh va hieu kh, x ly hieu kh thng nhanh va c ng dungnhieu.

Qua trnh x ly k kh hoac hieu kh thng c s dung nh ao sinh hoc, loc nho giot, bun hoat tnh, be tiep xuc sinh hoc quay va phan huy k kh.

X ly cap 3: loai thai phosphate, nitrate va vi sinh vat nham lamcho nc co the uong c va ngan can phu dng.

Ket tua hoa hoc, khu trung bang chlorine, loc qua cat va s dung aolang.

MoMo hhnhnh momo tata cacacc giaigiai oaoann xx lyly nncc thathaii

XL cap 1

XL cap 2 XL cap 3

HoHo sinhsinh hohocc

Thng ap dung cho nhng vung co nhieu anh sang

Ao tuy nghi thng nong (1-2.5 m) va cac qua trnhsinh hoc dien ra nh hnh (lam sach nc thai bangvi tao va vi sinh vat).

Ao hieu kh nong hn ao tuy nghi, thng 1 m eanh sang co the chieu xuyen en ay c.

Ao sinh hoc toc o cao nham bao am qua trnhong hoa cua tao dien ra manh tang sinh khoi tao.

Qua trnh lam sach nc thai bang tao va vi sinh vat theo W. J. Oswald (1977)

O nhiem hu cCarbon

Nitrogenphosphore

Sinh khoi tao

Vi khuanC68H95O27N4

Oxygen

Sinh khoi vi khuan

Vi taoC106H181O45N16P

Thc an onghoa trc tiep

CO2, NH4+, PO43-Bc xa mat tri

Nc thai cx ly

CO2 trong khongkh

San pham phuc s dung

O nhiem hu cCarbon

Nitrogenphosphore

Sinh khoi tao

Vi khuanC68H95O27N4

Oxygen

Sinh khoi vi khuan

Vi taoC106H181O45N16P

Thc an onghoa trc tiep

CO2, NH4+, PO43-Bc xa mat tri

Nc thai cx ly

CO2 trong khongkh

San pham phuc s dung

Ao lang co ket cau giong vi ao tuy nghi nhng c sdung giai oan 3 vi thi gian lu nc lau hn t 7 15 ngay cho phep chat ran co the c lang trc khi ncc thai ra ngoai.

Ao k kh chu yeu c s dung e x ly nc thai trckhi i vao ao tuy nghi. Cac ao thch hp cho gia tr BOD cao 300 mg/l.

Cac ieu kien k kh c duy tr bang cach tang o saucua ao t 1 7m va tang tai lng BOD. Thi giai lu nct 2 160 ngayvi kha nang loai thai BOD t 70 80%

Ao k kh khong giong cac ao khac c s dung trong x lycap I cua nc thai sinh hoat va nc thai cong nghiep.

Nc thai(BOD tren 300 mg/l)

Giai oan s cap

Giai oan II

Giai oan III

Ao k kh

BOD giam 50-70% trong 1- 5 ngay

Ao tuy nghi

20-40 ngay

Ao lang

1-7 ngay

Nc au ra(BOD < 25mg/l)

ThTh tt caca cc

aoaodudu ngng

chocho

xx lyly nn cc

thatha ii

AoAo kk khkh

CaCacc dadangng aoao hiehieuu khkh

So So sasanhnh hiehieuuquaqua xx lyly nnccthathaii trtrcc vava

sausau khikhi aapp dudungngAoAo hiehieuu khkh

TRTRCC

SAUSAU

Hien tng phu dng

Hoat ong hieu qua, khong o nhiem

AoAo tutuyy nghinghi

HIEU KH

TUY NGHI

K KH

CaCacc thongthong soso ooii vvii aoao tutuyy nghinghi

Thong so n v Gia tro sau m 1 3

Thi gian lu nc ngay 7 50

Tai lng BOD kg/acre/ngay 9 22

BOD5 c x ly % 70 95

Nong o tao mg/l 10 100

Nong o chat ran llng au ra

mg/l 100 - 350

LoLocc nhonho giogiott

Hau het vi sinh vat trong t nhien thng bamvao be mat chat ran va c biet la mang sinhhoc.

Mang sinh hoc phat trien tren be mat vat lieu, c cau tao chu yeu la vi khuan va nam.

Mang sinh hoc ngay cang day them, cac lpse c tach ra va nhng chat ran l lng nayc thu lai trong mot be lang.

HH ththngng phnphn phphii nncc

VaiVai trtr: : phunphun nncc lnln bb mmtt vvtt liliuu llccCCuu ttoo: : ngng ngng tmtm bb

2, 3 2, 3 ngng nhnhnh,cnh,c vivi hohocc ll phunphunngng nhnhnhnh: : Quay: Quay: ttcc quay: 1 quay: 1 vngvng/ 10ph/ 10phttCC nhnh: : bb trtr ll phunphun nncc phnphn bb uu trntrn

mmtt bb

SSnn vv thuthu nncc

PhanPhan loaloaii bebe lolocc sinhsinh hohocc nhonho giogiottTHNG STHNG S N VN V

O O TTI TRI TRNG NG THTHPP

TTI TRI TRNG NG CAO CAO

ChiChiuu caocao llpp vvttliliuu

mm 1 1 --33 0,9 0,9 --2,4 (2,4 ())6 6 --8 (8 (NhNhaa))

LoLoii vvtt liliuu cccc, , ongong, , cucuii, , than.than.

cccc, than , than cccc, , ssii llnn, , nhnhaa cc

TTii trtrngng BODBOD Kg BOD/ Kg BOD/ mm33.ngay.ngay

0.080.08--0.40.4 0.4 0.4 1.61.6

TTcc ttii ththyy mm33/m/m22.ng.ngyy 11--4.14.1 4.1 4.1 --40.740.7HH ss tutunn hohonn R = QR = QCC / Q/ Q TTyy chchnn : 0 : 0 --1 1 0.5 0.5 22TTcc ttii ththyy trntrnbb mmtt ccaa bb llngng22

mm33/m/m22.ng.ngyy 2525 1616

HiHiuu ququ xx ll BOD BOD sausau llcc vv llngng 22

%% 80 80 --9090 65 65 --8585

TuTunn hohonn nncc

LoLocc nhonho giogiott

Cac he thong loc c s dung rong rai cho xly cap II bi v

Chi ph xay, van hanh va bao dng thap

Thch ng vi s thay oi cua cac thanhphan nc thai.

Loc sinh hoc c s dung trong mot qua trnhn, cho nc au ra co tieu chuan cao.

Hnh 2.3. Be loc sinh hoc nho giotCau tao Be loc sinh hoc nho giotVat lieu loc

LoLocc nhonho giogiott

ngng dudungng lolocc nhonho giogiott ngoangoaii ththcc tete