Xu Ly Nuoc Thai Chan Nuoi Heo

7/31/2019 Xu Ly Nuoc Thai Chan Nuoi Heo

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MC LC

CHNG 1: M U .....................................................................................................11.1. Gii thiu .....................................................................................................................11.2. Tnh cp thit ca ti ..............................................................................................11.3. Mc tiu nghin cu ....................................................................................................2

1.4. Ni dung nghin cu ...................................................................................................21.5. Phm vi nghin cu .....................................................................................................2CHNG 2: TNG QUAN ..............................................................................................32.1. Thnh phn, tnh cht ca nc thi chn nui ..........................................................32.1.1. Cc cht hu c v v c .........................................................................................32.1.2. N v P ........................................................................................................................32.1.3. Vi sinh vt gy bnh .................................................................................................32.2. Cc nghin cu trong v ngoi nc v x l nc thi chn nui heo ....................32.2.1. Cc nc trn th gii ..............................................................................................32.2.2. Vit Nam ...............................................................................................................5

CC QUY TRNH X L CHT THI CHN NUI THAM KHO ...........................6i vi quy m h gia nh ....................................................................................................6i vi c s chn nui quy m nh .....................................................................................7

i vi c s chn nui quy m va v ln ......................................................................72.3. Cc phng php x l nc thi chn nui heo .......................................................82.3.1. Phng php x l c hc ........................................................................................82.3.2. Phng php x l ha l ........................................................................................92.3.3. Phng php x l sinh hc ...................................................................................102.3.3.1. Phng php x l hiu kh ...............................................................................102.3.3.2. Phng php x l k kh ..................................................................................102.3.3.3. Cc h thng x l nhn to bng phng php sinh hc ..................................11

2.3.3.4. Cc h thng x l t nhin bng phng php sinh hc ..................................142.3.3.5. ng dng thc vt nc x l nc thi ......................................................182.3.3.6. ng dng lc bnh x l nc thi ...............................................................19CHNG 3: XUT CC PHNG N X L NC THI CHN NUIHEO CNG SUT 500M3/NGY M .......................................................................243.1. C s la chn phng n x l nc thi ...............................................................243.2. Phng n 1 ...............................................................................................................253.3. Phng n 2 ..............................................................................................................26CHNG 4: TNH TON CHI TIT CC CNG TRNH N V THEOPHNG N 2 ................................................................................................................284.1. Li chn rc .............................................................................................................28

4.2. Ngn tip nhn ...........................................................................................................294.3. B lng ct .................................................................................................................304.4. B iu ha ................................................................................................................314.5. B lng t I ..............................................................................................................364.6. B UASB ...................................................................................................................404.7. B aerotank ................................................................................................................434.8. B lng II ...................................................................................................................524.9. B nn bn .................................................................................................................574.10. My p bn ..............................................................................................................604.11. H sinh hc thc vt ................................................................................................61CHNG 5: TNH KINH T .........................................................................................63


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n mn hc X L Nc Thi Lp HMT1

CHNG 1: M UCHNG 1: M U

1.1. Gii thiu1.1. Gii thiu

T ngn nm nay cuc sng ca ngi nng dn Vit Nam gn lin vi cy la vchn nui gia sc. Chn nui heo khng ch cung cp phn ln tht tiu th hng

ngy, l ngun cung cp phn hu c cho cy trng, m chn nui heo cn tn dng

thc n v thu ht lao ng d tha trong nng nghip. Vi nhng c tnh ring ca

n nh tng trng nhanh, vng i ngn chn nui heo lun c quan tm v n tr

thnh con vt khng th thiu c ca cuc sng hng ngy trong hu ht cc gia

nh nng dn. Trong nhng nm gn y i sng ca nhn dn ta khng ngng

c ci thin v nng cao, nhu cu tiu th tht trong ch yu l tht heo ngy

mt tng c v s lng v cht lng thc y ngnh chn nui heo bc sang

bc pht trin mi. Hin nay trn c nc ta xy dng nhiu m hnh chn tri

chn nui heo vi quy m ln, ch yu phn b ti 5 vng trng im l Mc Chu

(Sn La), H Ni v cc vng ph cn, khu vc TPHCM v cc tnh xung quanh,

Lm ng v mt s tnh duyn hi min Trung.

Bn cnh nhng mt tch cc, vn mi trng do ngnh chn nui gy ra angc d lun v cc nh lm cng tc mi trng quan tm. cc nc c nn chn

nui cng nghip pht trin mnh nh H Lan, Anh, M, Hn Quc, th y l mt

trong nhng ngun gy nhim ln nht. Vit Nam, kha cnh mi trng ca

ngnh chn nui ch c quan tm trong vi nm tr li y khi tc pht trin

chn nui ngy cng tng, lng cht thi do chn nui a vo mi trng ngy

cng nhiu, e da n mi trng t, nc, khng kh xung quanh mt cch

nghim trng.

1.2. Tnh cp thit ca ti1.2. Tnh cp thit ca ti

Ngun nc thi chn nui l mt ngun nc thi c cha nhiu hp cht hu

c, virus, vi trng, trng giun sn Ngun nc ny c nguy c gy nhim cc

tng nc mt, nc ngm v tr thnh nguyn nhn trc tip pht sinh dch bnh

cho n gia sc. ng thi n c th ly lan mt s bnh cho con ngi v nh

hng n mi trng xung quanh v nc thi chn nui cn cha nhiu mm bnh

nh: Samonella, Leptospira, Clostridium tetani,nu khng x l kp thi. Bn cnh

GVHD: ThS. Nguyn Xun Hon Trang 1


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cn c nhiu loi kh c to ra bi hot ng ca vi sinh vt nh NH3, CO2,

CH4, H2S, . . .Cc loi kh ny c th gy nhim c khng kh v ngun nc ngm

nh hg n i sng con ngi v h sinh thi. Chnh v vy m vic thit k h

thng x l nc thi cho cc tri chn nui heo l mt hot ng ht sc cn thit.

1.3. Mc tiu nghin cu1.3. Mc tiu nghin cu

Xc nh cc ch tiu ho l ca nc thi chn nui lm c s cho vic

xut cc phng n x l v la chn phng n kh thi nht tnh ton thit k.

1.4. Ni dung nghin cu1.4. Ni dung nghin cu

Xc nh thnh phn, mt s ch tiu ha l, ca nc thi chn nui.

Thu thp cc thng tin v cc phng php x l nc thi chn nui heo t cc tiliu.

xut cc dy chuyn x l nc thi chn nui heo v la chn phng n kh thi

nht.

Tng hp s liu, tnh ton thit k cc cng trnh n v.

1.5. Phm vi nghin cu1.5. Phm vi nghin cu

Ch p dng cho x l nc thi chn nui heo cng sut 500m3/ng. Khng p dngcho nc thi cc ngnh khc. Cht thi rn v kh khng tnh n trong n ny.



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CHNG 2: TNG QUANCHNG 2: TNG QUAN

2.1. Thnh phn, tnh cht ca nc thi chn nui2.1. Thnh phn, tnh cht ca nc thi chn nui

Nc thi chn nui l mt trong nhng loi nc thi rt c trng, c kh

nng gy nhim mi trng cao bng hm lng cht hu c, cn l lng, N, P v

sinh vt gy bnh. N nht thit phi c x l trc khi thi ra ngoi mi trng.

La chn mt quy trnh x l nc thi cho mt c s chn nui ph thuc rt nhiu

vo thnh phn tnh cht nc thi, bao gm:

2.1.1. Cc cht hu c v v c2.1.1. Cc cht hu c v v c

Trong nc thi chn nui, hp cht hu c chim 7080% gm cellulose,

protit, acid amin, cht bo, hidratcarbon v cc dn xut ca chng c trong phn,

thc n tha. Hu ht cc cht hu c d phn hy. Cc cht v c chim 2030%

gm ct, t, mui, ure, ammonium, mui chlorua, SO42-,

2.1.2. N v P2.1.2. N v P

Kh nng hp th N v P ca cc loi gia sc, gia cm rt km, nn khi n thc

n c cha N v P th chng s bi tit ra ngoi theo phn v nc tiu. Trong nc

thi chn nui heo thng cha hm lng N v P rt cao. Hm lng N-tng trong

nc thi chn nui 571 1026 mg/L, Photpho t 39 94 mg/L.

2.1.3. Vi sinh vt gy bnh2.1.3. Vi sinh vt gy bnh

Nc thi chn nui cha nhiu loi vi trng, virus v trng u trng giun sn

gy bnh.

2.2. Cc nghin cu trong v ngoi nc v x l nc thi chn nui heo2.2. Cc nghin cu trong v ngoi nc v x l nc thi chn nui heo

2.2.1. Cc nc trn th gii2.2.1. Cc nc trn th gii

Chu , cc nc nh: Trung Quc, Thi Lan, l nhng nc c ngnh

chn nui cng nghip ln trong khu vc nn rt quan tm n vn x l nc thi

chn nui.



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Nhiu nh nghin cu Trung Quc tm ra nhiu cng ngh x l nc thi

thch hp nh l:

K thut lc ym kh

K thut phn hy ym kh hai giai on

B Biogas t hoi

Hin nay Trung Quc cc b Biogas t hoi s dng rng ri nh phn

ph tr cho cc h thng x l trung tm. B Biogas l mt phn khng th thiu

trong cc h gia nh chn nui heo va v nh cc vng nng thn, n va x l

c nc thi v gim mi hi thi m cn to ra nng lng s dng.

Trong lnh vc nghin cu x l nc thi chn nui heo ti Thi Lan thtrng i hc Chiang Mai c nhiu ng gp rt ln.

- HYPHI (h thng x l tc cao kt hp vi h thng chy nt): h thng

HYPHI gm c thng lng, b chy nt v b UASB. Phn heo c tch lm 2

ng, ng th nht l cht lng c t cht rn tng s, cn ng th hai l phn

cht rn vi nng cht rn tng s cao, k thut ny c xy dng cho cc tri

heo trung bnh v ln.

Nga cc nh nghin cu cng nghin cu x l nc thi phn heo, phn b

di cc iu kin a lnh v a nng trong iu kin kh hu Nga.

Mt s tc gi c cho rng chin lc gii quyt vn x l nc thi chn

nui heo l s dng k thut SBR (sequencing batch reactor). i vi cc loi

nc thi giu Nit v Phospho nh nc thi chn nui heo th cc phng php x

l thng thng khng th t c cc tiu chun cho php v hm lng v Nit

v Phospho trong nc ra sau x l. Cng ngh x l nc thi chn nui giu cht

hu c a ra l SBR c th gim trn 97% nng COD, Nit, Phospho.

Nhn xt chung v cng ngh x l nc thi giu cht hu c sinh hc trn

th gii l p dng tng th v ng b cc thnh tu k thut ln men ym kh, ln

men hiu kh v ln men thiu kh, nhm p ng cc yu cu kinh t x hi v bo

v mi trng. Trn c s c th xut ra nhng gii php k thut ph hp vi

tng iu kin sn xut c th. S khi qut sau y l c s la chn m hnh xl thch hp.



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Hnh 2.1: S tng qut x l nc thi giu cht hu c sinh hc

2.2.2. Vit Nam2.2.2. Vit Nam

Vit Nam, nc thi chn nui heo c coi l mt trong nhng ngun

nc thi gy nhim nghim trng. Vic m rng cc khu dn c xung quanh ccx nghip chn nui heo nu khng c gii quyt tha ng s gy ra nhim mi

trng nh hng n sc khe cng ng v gy ra nhng vn mang tnh cht x

hi phc tp.

Nhiu nguyn cu trong lnh vc x l nc thi chn nui heo ang c ht

sc quan tm v mc tiu gii quyt vn nhim mi trng, ng thi vi vic

to ra nng lng mi. Cc nghin cu v x l nc thi chn nui heo Vit Namang tp trung vo hai hng chnh, hng th nht l s dng cc thit b ym kh

tc thp nh b ln mem to kh Biogas kiu Trung Quc, n , Vit Nam, hoc

dng cc ti PE. Phng hng th nht nhm mc ch xy dng k thut x l

ym kh nc thi chn nui heo trong cc h gia nh chn nui heo vi s u heo

khng nhiu. Hng th hai l xy dng quy trnh cng ngh v thit b tng i

hon chnh, ng b nhm p dng trong cc x nghip chn nui mang tnh cht

cng nghip. Trong cc nghin cu v quy trnh cng ngh x l nc thi chn nuiheo cng nghip a ra mt s kin ngh sau:

Cng ngh x l nc thi chn nui cng nghip c th tin hnh nh sau: (1)

x l c hc: lng 1; (2) x l sinh hc: bt u bng sinh hc k kh UASB, tip theo

l sinh hc hiu kh (Aerotank hoc h sinh hc); (3) kh trng trc khi thi ra

ngoi mi trng.

Nhn chung nhng nghin cu ca chng ta i ng hng, tip cn ccng ngh th gii ang quan tm nhiu. Tuy nhin s lng nghin cu v cht

lng cc nghin cu ca chng ta cn cn c nng cao hn, nhm nhanh chng

c p dng trong thc t sn xut.


B lng Nc ra

Ncthi vo

B iuha

Bn, cn

Phn hyym kh tc thp

UASB

Thp lcym kh

Phn hyym khti xc

Lc hiu khv thiu kh

RBC

L c hiu kh

AEROTANK

H thc vtthy sinh

Bn

Mctiu ktqu ch

yu

X l ym kh X l hiu kh

1) 90%BODBiogas2) 99% mm bnh bdit3 N P K cn n u n

1) N, P, K v ccloi yu t gy c2) Tip tc gimCOD v BOD


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CC QUY TRNH X L CHT THI CHN NUI THAM KHO

i vi quy m h gia nh

Do lng cht thi chn nui thi ra hng ngy cn t nn cc c s chn nui

h gia nh c th thu gom qut dn chung thng xuyn. C th p dng mt sbin php x l cht thi theo cc s sau :

Quy trnh 1:

Quy trnh 2:


CN LNG

H GA

PHN

B T HOI

NC

THI X L

THI RANGUN

NCTHICHN NUI

PHN BNPHN

HM BIOGAS H LNGNCTHICHN NUI

NCTHI X L

THI RANGUN

BIOGAS


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LNG

PHN

B SC KHUASB LNG

PHN BN THIRA

NGUN

PHN

NC THICHN NUI


i vi c s chn nui quy m nh

Ti cc c s chn nui quy m nh, lng phn gia sc thi ra hng ngy

khong vi trm kg, do vic s dng ti hoc biogas x l phn l khng kh

thi v tn rt nhiu din tch v cng xy dng. Trng hp ny ta c th tch ring

qu trnh x l phn v nc thi. Nc thi chn nui c x l bng h thng

biogas, phn c thu gom v x l ring bng qu trnh lm phn bn. Cn lng t

khu x l nc thi c thu gom x l chung vi phn v nc r trong qu trnh

phn c th a ngc tr li h thng x l nc thi.

Quy trnh:

i vi c s chn nui quy m va v lni vi c s chn nui quy m va v ln

Vi quy m va tr ln, vic u t cho mt h thng x l cht thi chn nui

l c th thc hin c. Ty vo trng hp c th m c th p dng mt s quy

trnh sau y:

Quy trnh 1:

Quy trnh 2:


NC

THICHNNUI

HM BIOGAS H LNG

PHN

NCTHI X L

THI RANGUN

CN LNG

PHN BNPHN


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i vi cc c s chn nui c quy m ln, rt ngn thi gian x l v tng

hiu qu x l, c th thm khu tin x l trc khu x l sinh hc hoc kt hp x

l sinh hc vi x l bc cao.

2.3. Cc phng php x l nc thi chn nui heo2.3. Cc phng php x l nc thi chn nui heo

Vic x l nc thi chn nui heo nhm gim nng cc cht nhim trong

nc thi n mt nng cho php c th x vo ngun tip nhn. Vic la chn

phng php lm sch v la chn quy trnh x l nc ph thuc vo cc yu t

nh :

Cc yu cu v cng ngh v v sinh nc.

Lu lng nc thi.

Cc iu kin ca tri chn nui.

Hiu qu x l.

i vi nc thi chn nui, c th p dng cc phng php sau :

Phng php c hc.

Phng php ha l.

Phng php sinh hc.

Trong cc phng php trn ta chn x l sinh hc l phng php chnh.

Cng trnh x l sinh hc thng c t sau cc cng trnh x l c hc, ha l.

2.3.1. Phng php x l c hc2.3.1. Phng php x l c hc

Mc ch l tch cht rn, cn, phn ra khi hn hp nc thi bng cch thu

gom, phn ring. C th dng song chn rc, b lng s b loi b cn th, d lng


LNGH K

KH

PHN

H TYNGHI

H HIUKH

THI RANGUN

PHN BNPHN

NCTHICHN

NUI


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to iu kin thun li v gim khi tch ca cc cng trnh x l tip theo. Ngoi ra

c th dng phng php ly tm hoc lc. Hm lng cn l lng trong nc thi

chn nui kh ln (khong vi ngn mg/L) v d lng nn c th lng s b trc ri

a sang cc cng trnh x l pha sau.

Sau khi tch, nc thi c a sang cc cng trnh pha sau, cn phn cht

rn c em i lm phn bn.

2.3.2. Phng php x l ha l2.3.2. Phng php x l ha l

Nc thi chn nui cn cha nhiu cht hu c, cht v c dng ht c kch

thc nh, kh lng, kh c th tch ra bng cc phng php c hc thng thng

v tn nhiu thi gian v hiu qu khng cao. Ta c th p dng phng php keo t loi b chng. Cc cht keo t thng s dng l phn nhm, phn st, phn bn,

kt hp vi polymer tr keo t tng qu trnh keo t.

Nguyn tc ca phng php ny l : cho vo trong nc thi cc ht keo mang

in tch tri du vi cc ht l lng c trong nc thi (cc ht c ngun gc silic v

cht hu c c trong nc thi mang in tch m, cn cc ht nhm hidroxid v st

hidroxi c a vo mang in tch dng). Khi th in ng ca nc b ph v,

cc ht mang in tri du ny s lin kt li thnh cc bng cn c kch thc ln

hn v d lng hn.

Theo nghin cu ca Trng Thanh Cnh (2001) ti tri chn nui heo 2/9:

phng php keo t c th tch c 80-90% hm lng cht l lng c trong nc

thi chn nui heo.

Ngoi keo t cn loi b c P tn ti dng PO43- do to thnh kt ta

AlPO4 v FePO4.Phng php ny loi b c hu ht cc cht bn c trong nc thi chn

nui. Tuy nhin chi ph x l cao. p dng phng php ny x l nc thi chn

nui l khng hiu qu v mt kinh t.

Ngoi ra, tuyn ni cng l mt phng php tch cc ht c kh nng lng

km nhng c th kt dnh vo cc bt kh ni ln. Tuy nhin chi ph u t, vn

hnh cho phng php ny cao, cng khng hiu qu v mt kinh t i vi cc tri

chn nui.



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2.3.3. Phng php x l sinh hc2.3.3. Phng php x l sinh hc

Phng php ny da trn s hot ng ca cc vi sinh vt c kh nng phn hy cc

cht hu c. Cc vi sinh vt s dng cc cht hu c v mt s cht khong lm

ngun dinh dng v to nng lng. Ty theo nhm vi khun s dng l hiu kh

hay k kh m ngi ta thit k cc cng trnh khc nhau. V ty theo kh nng v ti

chnh, din tch t m ngi ta c th dng h sinh hc hoc xy dng cc b nhn

to x l.

2.3.3.1. Phng php x l hiu kh2.3.3.1. Phng php x l hiu kh

S dng nhm vi sinh vt hiu kh, hot ng trong iu kin c oxy. Qu trnh

x l nc thi bng phng php hiu kh gm 3 giai on :Oxy ha cc cht hu c :

CxHyOz + O2 Enzyme

CO2 + H2O + H

Tng hp t bo mi :

CxHyOz + O2 + NH3 Enzyme

T bo vi khun (C5H7O2N) + CO2 + H2O - H

Phn hy ni bo :

C5H7O2N + O2 Enzyme

5CO2 + 2H2O + NH3 H

2.3.3.2. Phng php x l k kh2.3.3.2. Phng php x l k kh

S dng vi sinh vt k kh, hot ng trong iu kin ym kh khng hoc c

lng O2 ha tan trong mi trng rt thp, phn hy cc cht hu c.

Bn giai on xy ra ng thi trong qu trnh phn hy k kh :a. Thy phn : Trong giai on ny, di tc dng ca enzyme do vi khun tit

ra, cc phc cht v cc cht khng tan (nh polysaccharide, protein, lipid) chuyn

ha thnh cc phc cht n gin hn hoc cht ha tan (nh ng, cc acid amin,

acid bo).

b. Acid ha : Trong giai on ny, vi khun ln men chuyn ha cc cht ha

tan thnh cht n gin nh acid bo d bay hi, ru, acid lactic, methanol, CO2, H2,

NH3, H2S v sinh khi mi.



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c. Acetic ha : Vi khun acetic chuyn ha cc sn phm ca giai on acid

ha thnh acetat, H2, CO2 v sinh khi mi.

d. Methane ha : y l giai on cui ca qu trnh phn hy k kh. Acid

acetic, H2, CO2, acid formic v methanol chuyn ha thnh methane, CO2 v sinh

khi mi.

2.3.3.3. Cc h thng x l nhn to bng phng php sinh hc2.3.3.3. Cc h thng x l nhn to bng phng php sinh hc

a. X l theo phng php hiu kh

X l nc thi theo phng php hiu kh nhn to da trn nhu cu oxy cn

cung cp cho vi sinh vt hiu kh c trong nc thi hot ng v pht trin. Cc vi

sinh vt hiu kh s dng cc cht hu c, cc ngun N v P cng vi mt s nguyn

t vi lng khc lm ngun dinh dng xy dng t bo mi, pht trin tng sinh

khi. Bn cnh qu trnh h hp ni bo cng din ra song song, gii phng CO2

v nc. C hai qu trnh dinh dng v h hp ca vi sinh vt u cn oxy. p

ng nhu cu oxy ha tan trong nc, ngi ta thng s dng h thng sc kh b

mt bng cch khuy o hoc bng h thng kh nn.

Qu trnh x l hiu kh vi vi sinh vt sinh trng dng l lng (bnhot tnh)

Qu trnh ny s dng bn hot tnh dng l lng x l cc cht hu c ha

tan hoc cc cht hu c dng l lng. Sau mt thi gian thch nghi, cc t bo vi

khun bt u tng trng v pht trin. Cc ht l lng trong nc thi c cc t

bo vi sinh vt bm ln v pht trin thnh cc bng cn c hot tnh phn hy cc

cht hu c. Cc ht bng cn dn dn ln ln do c cung cp oxy v hp th cc

cht hu c lm cht dinh dng sinh trng v pht trin.

Bn hot tnh l tp hp cc vi sinh vt khc nhau, ch yu l vi khun, bn

cnh cn c nm men, nm mc, x khun, nguyn sinh ng vt, giun, sn, kt

thnh dng bng vi trung tm l cc ht l lng trong nc. Trong bn hot tnh ta

thy c loiZoogelea trong khi nhy. Chng c kh nng sinh ra mt bao nhy xung

quanh t bo, bao nhy ny l mt polymer sinh hc vi thnh phn l polysaccharide

c tc dng kt cc t bo vi khun li to thnh bng.



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Mt s cng trnh hiu kh ph bin xy dng trn c s x l sinh hc bng

bn hot tnh :

- B aeroten thng thng

i hi ch dng chy nt (plug-flow), khi chiu di b rt ln so vi chiurng. Trong b, nc thi vo c th phn b nhiu im theo chiu di, bn

hot tnh tun hon a vo u b. Tc sc kh gim dn theo chiu di b.

Qu trnh phn hy ni bo xy ra cui b.

- B aeroten xo trn hon ton

i hi chn hnh dng b, trang thit b sc kh thch hp. Thit b sc kh c kh

(motour v cnh khuy) hoc thit b khuch tn kh thng c s dng. Bny thng c dng trn hoc vung, hm lng bn hot tnh v nhu cu oxy

ng nht trong ton b th tch b.

- B aeroten m rng

Hn ch lng bn d sinh ra, khi tc sinh trng thp, sn lng bn thp

v cht lng nc ra cao hn. Thi gian lu bn cao hn so vi cc b khc (20-

30 ngy).

- Mng oxy ha

L mng dn dng vng c sc kh to dng chy trong mng c vn tc

xo trn bn hot tnh. Vn tc trong mng thng c thit k ln hn 3m/s

trnh lng cn. Mng oxy ha c th kt hp qu trnh x l N.

- B hot ng gin on (SBR)

B hot ng gin on l h thng x l nc thi vi bn hot tnh theo kiulm y v x cn. Qu trnh xy ra trong b SBR tng t nh trong b bn hot

tnh hot ng lin tc, ch c iu tt c qu trnh xy ra trong cng mt b v

c thc hin ln lt theo cc bc: (1) lm y, (2) phn ng, (3) lng, (4) x

cn, (5) ngng.

Qu trnh x l hiu kh vi vi sinh vt sinh trng dng dnh bm

Khi dng nc thi i qua nhng lp vt liu rn lm gi , cc vi sinh vt sbm dnh ln b mt. Trong s cc vi sinh vt ny c loi sinh ra cc polysaccaride c



15/70


tnh cht nh l mt polymer sinh hc c kh nng kt dnh to thnh mng. Mng

ny c dy thm vi sinh khi ca vi sinh vt dnh bm hay c nh trn mng. Mng

c to thnh t hng triu n hng t t bo vi khun, vi mt vi sinh vt rt

cao. Mng c kh nng oxy ha cc hp cht hu c, trong do t tip xc vi c cht

v t nhn c O2 s chuyn sang phn hy k kh, sn phm ca bin i k kh l

cc acid hu c, cc alcol,Cc cht ny cha kp khuch tn ra ngoi b cc vi

sinh vt khc s dng. Kt qu l lp sinh khi ngoi pht trin lin tc nhng lp

bn trong li b phn hy hp th cc cht bn l lng c trong nc khi chy qua

hoc tip xc vi mng.

b. X l theo phng php k kh

Qu trnh x l k kh vi vi sinh vt sinh trng dng l lng

-B x l bng lp bn k kh vi dng nc i t di ln (UASB)

V cu trc : B UASB l mt b x l vi lp bn di y, c h thng tch

v thu kh, nc ra pha trn. Khi nc thi c phn phi t pha di ln s i

qua lp bn, cc vi sinh vt k kh c mt cao trong bn s phn hy cc cht hu

c c trong nc thi. Bn trong b UASB c cc tm chn c kh nng tch bn bli ko theo nc u ra.

V c im : C ba qu trnh phn hy - lng bn - tch kh c lp t

trong cng mt cng trnh. Sau khi hot ng n nh trong b UASB hnh thnh loi

bn ht c mt vi sinh rt cao, hot tnh mnh v tc lng vt xa so vi bn

hot tnh hiu kh dng l lng.



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Hnh 2.2: B UASB

- B phn ng ym kh tip xc

Hn hp bn v nc thi c khuy trn hon ton trong b kn, sau c

a sang b lng tch ring bn v nc. Bn tun hon tr li b k kh, lng

bn d thi b thng rt t do tc sinh trng ca vi sinh vt kh chm. B phn

ng tip xc thc s l mt b biogas ci tin vi cnh khuy to iu kin cho vi

sinh vt tip xc vi cc cht nhim trong nc thi.

Qu trnh x l k kh vi vi sinh vt sinh trng dng dnh bm

- B lc k kh

B lc k kh l mt b cha vt liu tip xc x l cht hu c cha nhiu

cacbon trong nc thi. Nc thi c dn vo b t di ln hoc t trn xung,

tip xc vi lp vt liu c cc vi sinh vt k kh sinh trng v pht trin.

- B phn ng c dng nc i qua lp cn l lng v lc tip qua lp vt liu

lc c nh.

L dng kt hp gia qu trnh x l k kh l lng v dnh bm.

2.3.3.42.3.3.4. Cc h thng x l t nhin bng phng php sinh hc. Cc h thng x l t nhin bng phng php sinh hc

a. H sinh hc

Ngi ta c th ng dng cc quy trnh t nhin trong cc ao, h x l nc

thi. Trong cc h, hot ng ca vi sinh vt hiu kh, k kh, qu trnh cng sinh ca

vi khun v to l cc qu trnh sinh hc ch o. Cc qu trnh l hc, ha hc bao

gm cc hin tng pha long, lng, hp ph, kt ta, cc phn ng ha hc cng

din ra ti y. Vic s dng ao h x l nc thi c u im l t tn vn u t

cho qu trnh xy dng, n gin trong vn hnh v bo tr. Tuy nhin, do cc c ch

x l din ra vi tc t nhin (chm) do i hi din tch t rt ln. H sinhhc ch thch hp vi nc thi c mc nhim thp. Hiu qu x l ph thuc s



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pht trin ca vi khun hiu kh, k kh, ty nghi, cng vi s pht trin ca cc loi

vi nm, ru, to v mt s loi ng vt khc nhau.

H h sinh hc c th phn loi nh sau:

(1) H hiu kh (Aerobic Pond); (2)H ty nghi (Facultative Pond); (3) H kkh (Anaerobic Pond); (4) H x l b sung.

H hiu kh (Aerobic Pond)

H lm thong t nhin

Oxy c cung cp cho qu trnh oxy ha cht hu c ch yu do s khuch tn

khng kh qua mt nc v qu trnh quang hp ca cc thc vt nc (rong, to,).

Chiu su ca h phi b (thng ly khong 30-40 cm) m bo cho iu kinhiu kh c th duy tr ti y h. Trong h, nc thi c x l bi qu trnh cng

sinh gia to v vi khun, cc ng vt bc cao hn nh nguyn sinh ng vt cng

xut hin trong h v nhim v ca chng l lm sch nc thi (n cc vi khun).

Cc nhm vi khun, to hay nguyn sinh ng vt hin din trong h ty thuc vo

cc yu t nh lu lng np cht hu c, khuy trn, pH, dng cht, nh sng v

nhit .

Hiu sut chuyn ha BOD5 ca h rt cao, c th ln n 95%. Tuy nhin, ch

c BOD5 dng ha tan mi b loi khi nc thi u vo, v trong nc thi u ra

cha nhiu t bo to v vi khun, do nu phn tch tng BOD 5 c th s ln hn

c tng BOD5 ca nc thi u vo. Nhiu thng s khng th khng ch c nn

hin nay ngi ta thng thit k theo lu lng np t t cc m hnh th nghim.

Vic iu chnh lu lng np phn nh lng oxy c th t c t quang hp v

trao i kh qua b mt tip xc nc, khng kh.

Do su nh, thi gian lu nc di nn din tch ca h ln. V th h ch

thch hp khi kt hp vic x l nc thi vi nui trng thy sn cho mc ch chn

nui v cng nghip.

H hiu kh lm thong nhn to

Ngun oxy cung cp cho qu trnh sinh hc t cc thit b nh bm kh nn hay

my khuy c hc. V c tip kh nhn to nn chiu su ca h c th t 2 - 4,5



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m. Sc cha tiu chun khong 400 kg/(ha.ngy). Thi gian lu nc trong h 1-3

ngy.

H hiu kh lm thong nhn to do c chiu su h ln, mt khc vic lm

thong cng kh m bo ton phn v th mt phn ln ca h lm vic nh h

hiu-k kh, ngha l phn trn hiu kh, phn di k kh.

H ty nghi ( Facultative Pond )

Vic x l nc thi tt l do hot ng ca cc vi sinh vt hiu kh, k kh v

ty nghi. T trn xung y h c 3 khu vc chnh.

- Khu vc th nht (hay l khu vc hiu kh) c c trng bi h cng sinh

gia vi khun v to. Ngun oxy c cung cp bi oxy kh tri thng qua qu trnhtrao i t nhin qua b mt h, v oxy c to ra qua qu trnh quang hp ca to.

Oxy c vi khun s dng phn hy cc cht hu c to nn cc dng cht v

CO2, to s dng cc sn phm ny quang hp.

- Khu vc trung gian (hay l khu vc k kh khng bt buc) c trng bi cc

hot ng ca cc vi khun k kh khng bt buc.

- Khu vc th ba (hay l khu vc k kh) c trng bi cc hot ng ca cc

vi khun k kh phn hy cc cht hu c lng ng di y b.

Hnh 2.3: H ty nghi

H k kh ( Anaerobic Pond )



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H k kh c s dng x l nc thi c hm lng cht rn cao. Thng

thng y l mt ao su (c th n 9,1 m) vi cc ng dn nc thi u vo v

u ra c b tr mt cch hp l. iu kin k kh c duy tr sut chiu su ca

b. Vic n nh nc thi c tin hnh thng qua qu trnh kt ta, phn hy k

kh ca vi sinh vt. Hiu qu kh BOD5 thng mc 70% v c th ln n 85%

khi cc iu kin mi trng t ti u.

H x l b sung

C th p dng sau qu trnh x l sinh hc (aerotank, b lc sinh hc hoc sau

h sinh hc hiu kh, ty nghi,) t cht lng nc ra cao hn, ng thi thc

hin qu trnh nitrat ha. Do thiu cht dinh dng, vi sinh cn li trong h ny sng

giai on h hp ni bo v amoniac chuyn ha thnh nitrat. Thi gian lu nc

trong h ny khong 18 - 20 ngy. Ti trng thch hp 67 - 200kg BOD5/ha.ngy.

b. Cnh ng ti

Dn nc thi theo h thng mng t trn cnh ng ti, dng bm v ng

phn phi phun nc thi ln mt t. Mt phn nc bc hi, phn cn li thm vo

t to m v cung cp mt phn cht dinh dng cho cy c sinh trng.

Phng php ny ch c dng hn ch nhng ni c khi lng nc thi nh,

vng t kh cn xa khu dn c, bc hi cao v t lun thiu m.

cnh ng ti khng c trng rau xanh v cy thc phm v vi khun,

virus gy bnh trong nc thi cha c loi b c th gy tc hi cho sc khe ca

con ngi s dng cc loi rau v thc phm ny.

c. X nc thi vo ao, h, sng sui

Nc thi c x vo nhng ni vn chuyn v cha nc c sn trong t

nhin pha long chng v tn dng kh nng t lm sch ca cc ngun. i vi

nc thi chn nui heo, bin php ny thng khng c p dng v n gy mi

hi thi rt nghim trng v git cht cc loi thy sinh vt sng trong nc. Mc d

vy nc ta, phn ln nc thi chn nui thng x vo cc h thng sng, h gn

khu vc chn nui sau khi x l bng nhng bin php th s nh hm biogas, h

lng,



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Ngoi cc phng php sinh hc t nhin trn, ngi ta cn s dng cc phng

php vng t ngp nc (wetland), x l bng t (land treatment), Hin nay

ngi ta p dng vic s dng cc loi thc vt nc lm tng hiu qu x l

t nhin ca cc ao h, c bit thch hp vi nc thi chn nui.

2.3.3.5. ng dng thc vt nc x l nc thi2.3.3.5. ng dng thc vt nc x l nc thi

Thc vt nc thuc loi tho mc, thn mm. Qu trnh quang hp ca cc

loi thy sinh hon ton ging cc thc vt trn cn. Vt cht c trong nc s c

chuyn qua h r ca thc vt nc v i ln l. L nhn nh sng mt tri tng

hp thnh vt cht hu c. Cc cht hu c ny cng vi cht khc xy dng nn t

bo v to ra sinh khi. Thc vt ch tiu th cc cht v c ha tan. Vi sinh vt s

phn hy cc hp cht hu c v chuyn chng thnh cc cht v hp cht v c ha

tan thc vt c th s dng chng tin hnh trao i cht. Qu trnh v c ha

bi VSV v qu trnh hp th cc cht v c ha tan bi thc vt nc to ra hin

tng gim vt cht c trong nc. V vy ngi ta ng dng thc vt nc x l

nc thi.

V c ha Quang hp

Cc cht hu c Cc cht v c ha tan Sinh khi thc vt

Sinh khi vi sinh vt

C 3 loi thc vt nc chnh:

- Thc vt nc sng chm :

Loi thc vt nc ny pht trin di mt nc v ch pht trin c ngunnc c nh sng. Chng gy nn cc tc hi nh lm tng c ca ngun

nc, ngn cn s khuch tn ca nh sng vo nc. Do cc loi thc vt nc

ny khng hiu qu trong vic lm sch nc thi.

- Thc vt nc sng tri ni :

R ca thc vt ny khng bm vo t m l lng trn mt nc, thn v l

pht trin trn mt nc. N tri ni trn mt nc theo gi v dng nc. R cachng to iu kin cho vi khun bm vo phn hy nc thi.



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- Thc vt sng na chm na ni :

Loi thc vt ny c r bm vo t nhng thn v l pht trin trn mt nc.

Loi ny thng sng nhng ni c ch thy triu n nh.

Mt s thc vt nc ph bin (Chongrak Polprasert, 1997)

Loi Tn thng thng Tn khoa hcThc vt nc sng

chm

Hydrilla Hydrilla verticillata

Water milfoil Myriophyllum spicatum

Thc vt nc sng niLc bnh Eichhornia crassipesBo tm Wolfia arrhigaBo tai tng Pistia stratiotes

Thc vt nc sng nachm na ni

Cattails(c ui mo) Typha spp

Bulrush(c li bc) Scirpus sppReed(lau sy) Phragmites communis

2.3.3.6. ng dng lc bnh x l nc thi2.3.3.6. ng dng lc bnh x l nc thi

Lc bnh c tn khoa hc lEichhoria crassipes. nc ta lc bnh cn c tn

l bo Ty, bo Nht Bn.

Hnh 2.4: Hnh dng ca cy lc bnh

Lc bnh l cy thn tho, tri ni trn mt nc. Thn gm mt ci trc mang

nhiu lng ngn v nhng t mang r v l.

R si, c nh, khng phn nhnh, mc thnh chm di, chim 20 50% trng

lng ca cy ty theo mi trng sng nhiu hay t cht dinh dng.



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L mc theo dng hoa th, cung phng ln thnh phao ni. Cy con phao ngn

v phng to, cy gi cc phao ko di c th ti 30 cm. Tnh ni ca lc bnh l do t

l cao ca kh trong cung l (chim 70% th tch).

Hoa khng u, mu xanh nht hoc tm. i v cnh hoa cng mu dnh lin

vi nhau gc, cnh hoa trn c m vng.

Lc bnh sinh trng v pht trin nhit 10oC 40oC nhng mnh nht

nhit 20oC 30oC, v vy nc ta lc bnh sng quanh nm.

Vai tr ca cc b phn ca thc vt nc trong h thng x l (Chongrak

Polprasert, 1997)

Phn c th Nhim vR v/hoc

thn

L gi bm cho vi khun pht trin

Lc v hp ph cht rnThn v/hoc

l mt nc

hoc pha trn

mt nc

Hp th nh sng mt tri do ngn cn s pht trin ca toLm gim nh hng ca gi ln h x lLm gim s trao i gia nc v kh quyn

Chuyn oxy t l xung r

H thng x l nc thi bng h lc bnh c th xem nh l mt b lc sinh

hc nh git, vn tc thp c dng chy theo chiu ngang. C ch loi cht nhim

ca h thng ch yu l lng v phn hy sinh hc, b r ca chng c tc dng nh

mt b lc c hc v to gi bm cho vi sinh vt.

Oxy dng oxy ha cht hu c trong h c cung cp bi s khuch tn

ca khng kh, s quang hp ca to v gii phng t r ca lc bnh thng qua lp

biofilm. Hai qu trnh u tin chuyn i oxy trc tip bn trong nc, trong khi qu

trnh th ba oxy c gii phng thng qua lp biofilm.

S khuch tn ca khng kh lin quan n hiu qu ca qu trnh di chuyn

oxy qua li. Oxy di chuyn qua b mt ca h khong 0.5-1.5g/m3.ngy (Imhoff et al

1971). Trong h lc bnh, s di chuyn ny km hn do lc bnh che ph mt h v

s chuyn ng khng u ca gi.



23/70


Mt khc to khng tham gia qu trnh oxy ha khi lc bnh che ph b mt nn

oxy c c do s quang hp ca to gim ng k(Gee&Jensen, 1980, trch dn bi

R. Sooknah, 1999). Ngun oxy ch yu c gii phng t r lc bnh.

Oxy t r lc bnh di chuyn vo nc thng qua lp biofilm. Gi thuyt v cu

trc ca lp biofilm c ngh bi Timberlake (Timberlake et al, 1988). Theo tc

gi, lp biofilm c th c 4 vng cho vi khun hot ng, lp nitrat ha nm gn

vng cung cp, lp ln men ym kh nm gn b mt cht lng v 2 lp trung gian l

kh nitrat v s oxy ha hectotrophic. Do nng oxy trong nc gim theo

chiu su.

C ch loi cht hu c BOD5

Trong cc h x l, cc cht rn lng c s lng xung y di tc dng ca

trng lc v sau b phn hy bi cc vi sinh vt k kh. Cc cht rn l lng hoc

hu c ha tan c loi i bi hot ng ca cc vi sinh vt nm l lng trong nc

bm vo thn v r ca lc bnh. Vai tr chnh ca vic loi cht hu c l do hot

ng ca cc vi sinh vt, vic hp thu trc tip do lc bnh khng ng k nhng lc

bnh to gi bm cho cc vi sinh vt thc hin vai tr ca mnh.

C ch loi N

B hp th bi lc bnh v sau khi lc bnh c thu hoch th N

c loi khi h thng.

S bay hi ca amoniac. Qu trnh nitrat ha v kh nitrat ha ca cc vi sinh vt.

Trong qu trnh nitrat ha v kh nitrat ha gp phn ln nht. Lc bnh

cung cp gi bm cho cc vi khun nitrat ha. qu trnh nitrat ha c th xy ra,

hm lng DO phi mc 0,61,0 mg/L. Do su m qu trnh nitrat ha c th

xy ra quan h mt thit vi lu lng np BOD v tc chuyn ha oxy vo nc.

Qu trnh kh nitrat ha din ra trong iu kin thiu kh (anoxic) v qu trnh ny



24/70


cn phi cung cp thm ngun carbon cho cc vi sinh vt tng hp cc t bo ca n

v pH phi duy tr mc trung tnh.

C ch loi P

P trong nc thi c kh i do lc bnh hp th vo c th, b hp ph haykt ta. Trong c ch kh P, hin tng kt ta v hp ph gp phn quan trng nht

(Whigram et al, 1980 trch dn bi L Hong Vit, 2000). Tuy nhin, hiu sut ca

qu trnh ny kh c th tin on c. Qu trnh hp ph v kt ta ph thuc vo

cc nhn t nh l pH, kh nng oxy ha kh, hm lng st, nhm, canxi v cc

thnh phn st.

Cui cng, P s c loi b khi h thng qua vic :

Thu hoch lc bnh.

Vt bn lng y.

Cng dng ca lc bnh

Lc bnh l mt trong cc thc vt nc c tc tng trng nhanh nht, kh

nng cnh tranh dinh dng v cc yu t cn thit cho s sng ca lc bnh cao hn

hn so vi cc thc vt nc khc. Trong mt thi gian ngn, lc bnh pht trin sinhkhi lm kn c mt h. Ngi dn thng thu hoch lc bnh tn dng vo cc mc

ch sau :

Lm nguyn liu cho cc ngnh th cng

Hin nay Vit Nam, lc bnh ang thiu trong ngh an gi xut khu, gi

lc bnh kh l 6,500-7000/kg. Lc bnh rt c gi tr kinh t.

Lm thc phm cho gia sc

Lm phn xanh

Lc bnh l mt trong nhng nguyn liu dng sn xut phn xanh rt c hiu

qu v thnh phn dinh dng trong lc bnh kh cao.

Dng sn xut kh sinh hc biogas



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Lc bnh c cc vi sinh vt k kh phn gii to thnh sn phm cui cng

ca qu trnh phn hy l kh CH4, kh ny c th tn dng lm kh t trong vic

to ra nng lng cho sinh hot hay cho cc ngnh sn xut.

Hnh 2.5: H hiu kh c s dng thc vt nc l lc bnh



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CHNG 3: XUT CC PHNG N XCHNG 3: XUT CC PHNG N X

L NC THI CHN NUI HEO CNGL NC THI CHN NUI HEO CNG

SUT 500MSUT 500M33/NGY M/NGY M

3.1. C s la chn phng n x l nc thi3.1. C s la chn phng n x l nc thi

xc nh c dy chuyn cng ngh x l cn phi phn tch c cc ch tiu

gy nhim, cng vic ny c tnh cht rt quan trng v n quyt nh dy chuyn

cng ngh v hiu sut ca qu trnh x l nc thi.

Lng nc thi chn nui ch yu l t cng on tm cho heo v ra chung, v

vy m thnh phn ca nc thi ch yu l ca phn v nc tiu. l l do m

hm lng BOD, Nit tng v photpho tng trong nc thi cao. Cng vic loi b

Nit v photpho trong nc l rt kh, thng c x l bng phng php sinhhc.

Thnh phn nc thi chn nui heo

c tnh Nng n vTiu chn thi ngun

loi B (5945-1995)pH 7,2 5,5-9BOD5

2817 mg/L 50COD 5210 mg/L 100SS 615 mg/L 100

Ntng 206 mg/L 60Ptng 37 mg/L 6Coliform 5,8.109 MPN/100mL -



27/70


3.2. Phn3.2. Phng n 1g n 1

Thuyt minh qui trnh cng ngh

Nc thi c a qua li chn rc nhm loi b mt phn rc c kch thc

ln, rc t y c thu gom v em i chn lp. Sau nc thi c a qua b

lng ct. Ti y, lng ct c trong nc thi s lng xung v c em i san lp.

Nc t b lng ct tip tc qua b iu ha n nh lu lng v nng . Sau

, nc thi c bm n b lng t I tch mt phn cht hu c d lng. Bn

thu c ti y l dng bn ti, c bm v b nn bn. Nc thi c tip tc

bm qua b UASB, sau cng trnh ny nc c a qua b lc sinh hc cao ti.


Nc thi

ng ncng bn

B lng ct

B iu ha

B lng 1

B UASB

B lng 2

B lc sinhhc cao ti

B tip xc

B nn bn

Ngun tip nhn

San lp

My nnbn

Li chn rc

Nc sau tch bn

Chn lp

ng khng ct

Mythi kh

Lm phnbn


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Nc thu c cho chy qua b lng t 2, sau kh trng bng clo trc khi a

ra ra ngun tip nhn.

u im

Din tch cng trnh nh. Hiu qu x l tng i cao, nc u ra t tiu chun.

Khuyt im

B lc sinh hc cao ti d b tt nghn theo thi gian.

Tn chi ph ha cht.

Chi ph vn hnh cao.

3.3. Phng n 23.3. Phng n 2


Nc thi

ng ncng bn

Ngn tip nhn

B lng ct

B iu ha

B lng 1

B UASB

B lng 2

B aerotank

H sinh hc

B nn bn

Ngun tip nhn

San lp

My nn bn

Li chn rc

Nc sau tch bn

Chn lp

ng khng ct

Lm phn

bn

Mythi kh


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Thuyt minh qui trnh cng ngh

Nc thi c a qua li chn rc nhm loi b mt phn rc c kch

thc ln, rc t y c thu gom v em i chn lp. Sau nc thi c a

vo ngn tip nhn ri qua b lng ct. Ti y, lng ct c trong nc thi s lng

xung v c em i san lp. Nc t b lng ct tip tc qua b iu ha n

nh lu lng v nng cc cht gy nhim. Sau , nc thi c bm n b

lng t I c dng b lng ly tm tch mt phn cht hu c d lng. Bn thu

c ti y c bm v b nn bn. Nc thi tip tc qua b UASB. Ti b

UASB, cc vi sinh vt k kh dng l lng s phn hy cc cht hu c c trong

nc thi thnh cc cht v c dng n gin v kh CO2, CH4, H2S. Trong bUASB c b phn tch 3 pha: kh , nc thi v bn. Nc thi sau khi c tch

bn v kh c dn sang b Aerotank. Ti y din ra qu trnh phn hy hiu kh

cc hp cht hu c. B c thi kh lin tc nhm duy tr iu kin hiu kh cho vi

sinh vt pht trin. Sau nc thi c dn sang b lng II, ti y din ra qu

trnh phn tch nc thi v bn hot tnh. Bn hot tnh lng xung y, nc thi

pha trn c dn qua h sinh hc x l tip. Nc thi sau khi qua h sinh hc

t tiu chun loi B s c thi ra ngun tip nhn.

u im

H thng x l nc thi vn hnh tng i d dng.

Nc u ra t tiu chun.

Kh thi v mt kinh t.

Khuyt im

Tn nhiu din tch do s dng h sinh hc trong qu trnh x l.

Qu trnh vn hnh cn phi theo di thng xuyn cng sc kh trong b.



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CHNG 4: TNH TON CHI TIT CCCHNG 4: TNH TON CHI TIT CC

CNG TRNH N V THEO PHNG N 2CNG TRNH N V THEO PHNG N 2

4.1. Li chn rc4.1. Li chn rc

4.1.1. Nhim v

Li chn rc c nhim v tch cc vt th nh gi, rc, v hp, cc mu ,

g v cc vt khc trc khi a vo cc cng trnh x l pha sau. Li chn rc c

th t c nh hoc di ng, li chn rc gip trnh cc hin tng tc nghn

ng ng, mng dn v gy tt nghn bm.4.1.2. Tnh ton

Lu lng nc thi ra ca tri chn nui l Q t = 500(m3/ng). Thi gian tm heo

trong ngy l 3 ln, mi ln l t 5h - 7h, 9h - 11h v t 16 - 18h. Thi gian nc thi

ra trong mt ngy l 6 gi, vy lu lng trong 1 gi l:

( )3500

83,33 m / h6h

QQ

t= = =

Chn li c nh dng lm c kch thc mt li d = 0,35mm tng ng viti trng LA = 700l/phut.m2, t hiu qu x l cn l lng E = 10%.

Gi s li chn rc c chn theo thit k nh hnh c kch thc li B* L =

0,8 x 1,2 m.

Din tch b mt li:

2

2 3* *

83,33 / 1 1000 1,98700 / . 60

h

A

Q m h h l mAL l ph m ph m

= = =

S li chn rc

21,982

. 0,8 .1,2

A mn luoi

B L m m= = =

Ti trng lm vic thc t3

2

3* *

83,33 / 1 1000 723 / .0,8 *1,2 *2 60* *

th h

A

Q m h h l l p h mLm m phL B n m

= = =

Tng lng SS sau khi qua li chn rc gim 10%

SS cn li = 615.(1 0,1) = 553,5(mg/l)



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4.2. Ngn tip nhn4.2. Ngn tip nhn

4.2.1. Nhim v

Nc thi t tri chn nui heo sau khi qua li chn s chy n ngn tip nhn.T y nc thi c a i phn phi cho cc cng trnh x l tip theo.

4.2.2. Tnh ton

Th tch hu ch ca ngn tip nhn c tnh theo cng thc:

31. 83,33.30. 41,7( )60hV Q t m= = =

Vi : t l thi gian lu nc trong ngn tip nhn, t = 10 30 pht.

Chn t = 30 pht

Kch thc ngn tip nhn:

Chn chiu su hu ch h = 2 m

Chiu cao bo v hbv = 0,5 m

Chiu cao xy dng ngn tip nhn: H = h + hbv = 2,5 (m)==> 2

41,720,85( )

2

VB L m

h = = =

Chn B = 4 m , L = 5 m

Vy kch thc ngn tip nhn l: L x B x H = 5 x 4 x 2,5m.

Tnh bm chm bm nc thi

Cng sut ca bm c tnh theo cng thc:

. . . 1000.9,81.6.83,33 1,7( )1000 1000.0,8.3600g H QN kW

= = =


Mt bng ngn tip nhn Mt ct 1 - 1


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Vi:

Q : lu lng nc thi (m3/s).

H : chiu cao ct p ton phn, H = 6 (mH2O).

: khi lng ring ca nc (kg/m3).

: hiu sut bm (%).

Cng sut thc t ca my bm:

NTT = 1,2.N = 1,2.1,7 = 2 (kW)

Chn 2 bm cng sut 2kW, 1 bm hot ng v 1 bm d phng.

Bng tng hp cc thng s thit k ngn tip nhn

STT Tn thng s n v Kch thc

1 Chiu di m 52 Chiu rng m 43 Chiu cao m 2,54 Thi gian lu nc pht 30

4.3. B lng ct4.3. B lng ct

4.3.1 Nhim v

Nhim v ca b lng ct l lng cc ht cn c kch thc ln nhm bo v ccthit b my mc khi b mi mn, gim s lng ng cc vt liu nng trong ng,

knh, mng dn

B lng ct dng tch cc hp phn khng tan v c ch yu l ct ra khi

ngun nc.

4.3.2. Tnh ton

B lng ct ngang phi m bo vn tc chuyn ng ca nc l 0,15 m/s v

0,3 m/s v thi gian lu nc trong b l 30s t 60s (iu 6.3.20 TCXD 51 84).

Chn thi gian lu ca b lng ct ngang: t = 60s

Ch vn tc nc trong b lng ngang: vn = 0,2 (m/s)

Th tch tng cng ca b lng ct ngang

383,33.60. 1,4( )3600s

W Q t m= = =

Din tch mt ct ngang ca b lng ct ngang

283,33 0,120,2.3600

sn

n

QF m

v= = =



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Chiu rng ca b lng ct ngang

0,120,4

0,3nFB m

H= = =

Vi H: chiu cao cng tc ca b lng ct ngang 0,25m -1m. (iu 6.3.4 TCXD

51-84). Chn H = 0,3 m.Chia b lng ct thnh 2 n nguyn n = 2.

Chiu di ca b lng ngang

1,45,83

* * 2*0,4*0,3

WL m

n B H= = =

Chn L = 6m

Lng ct trung bnh sau mi ngy m

0 3* 500*0,15 0,075 /1000 1000

tbngayc

Q qW m ngaydem= = =

Vi q0: lng ct trong 1000m3

nc thi, q0= 0,15m3ct/ngaydem

Chiu cao lp ct trong b lng ct ngang trong 1 ngy m:

* 0,075*10,016

* * 6*0,4*2c x

c

W th m

L B n= = =

Vi tx = 1: chu k ly ct l 1 ngy m

Chiu cao xy dng ca b:HXD = h + hc + hbv = 0,3 + 0,016 + 0,3 = 0,62m

Trong :

h : chiu cao cng tc ca b lng ct; h = 0,5m.

hc : chiu cao lp ct trong b; hc = 0,0125m.

hbv: chiu cao bo v; hbv = 0,3 m.

4.4. B iu ha4.4. B iu ha4.4.1. Nhim v

B iu ho c nhim v iu ho lu lng v nng nc thi dng vo,

trnh lng cn v lm thong s b, qua oxy ho mt phn cht hu c trong nc

thi. Nc thi c n nh v lu lng v nng thun li cho vic x l

cc cng trnh x l sau, nht l s trnh c hin tng qu ti ca h thng x l.

m bo iu ho nng , lu lng v trnh lng cn, b c b tr h

thng thi kh lm vic lin tc.

4.4.2. Tnh ton



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Chn thi gian lu nc ca b iu ho t = 6h (quy phm 6 - 12h).

Th tch cn thit ca b:

V = htbQ . t = 20,83.8 = 166,67 (m3)

Chn chiu cao hu ch ca b iu l H = 4m.

Chiu cao bo v l Hbv = 0,3m.

Chiu cao xy dng b iu ha l 4,3m.

Din tch b:

2166,67 41,67( )4

VF m

H= = =

Chn chiu rng b l 6m, chiu di b l 7m.

Vy kch thc b iu ha l L x B x H = 7 x 6 x 4,3 (m).

Tnh ton h thng sc kh

Chn khuy trn b iu ha bng h thng thi kh. Lng kh nn cn cho thit

b khuy trn:

qkh = R * Vdh = 0,012 m3/m3.pht * 208,42m3 = 2,5m3/pht = 2500 l/pht.

Trong :

R: tc kh nn, R = 10 15 l/m3.pht.

Chn r = 12l/m3

.pht = 0,012 m3

/m3

.phtVdh: th tch ca b iu ho

Cc thng s cho thit b khuch tn kh

Loi khuch tn kh

Cch b tr

Lu lng kh

(l/pht.ci)

Hiu sut chuyn ho oxy

Tiu chun su 4.6m, %a s - li

Chp s - li

Bn s - li

ng plastic xp cng b tr:

Dng li

Hai pha theo chiu di( dng

chy xon hai bn)

Mt pha theo chiu di(dng

chy xon mt bn)ng plastic xp mm b tr:

11 96

14 71

57 142

68 113

85 311

57 340

25 40

27 39

26 33

28 32

17 28

13 25



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Dng li

Mt pha theo chiu di

ng khoan l b tr:

Dng li

Mt pha theo chiu di

28 198

57 198

28 113

57 170

25 36

19 37

22 29

15 19

Chn khuch tn kh bng a s b tr dng li. Vy s a khuch tn l:

n =2500

3080

kkq

r= = (a)

Trong : r: lu lng kh, chn r = 80 l/pht. a.

Cc a c b tr dng li u khp y b.

Phn phi a thnh 6 hng theo chiu di, mi hng 5 a.

Chn ng ng dn kh:

Vi lu lng kh qkk = 2,5 m3/pht = 0,042 m3/s v chn vn tc kh trong

ng vkk= 10 m/s (v = 10 15 m/s) c th chn ng knh ng chnh :

4 4.0,0420,07( )

. .10kkqD mv

= = =

Chn ng chnh c ng knh 75mm.

i vi ng nhnh c lu lng3

3 30,042 / 7.10 /6nm s

q m s= = v chn vn tc

trong ng nhnh l 10 m/s ng knh ng nhnh l:

34 4.7.100, 03( )

. .10kk

n

qD m

v

= = =

Chn ng chnh c ng knh 32 mm.

p lc v cng sut ca h thng nn kh

p lc cn thit cho h thng nn kh xc nh theo cng thc:

Htc = hd + hc + hf+ H

Trong :

hd: tn tht p lc do ma st dc theo chiu di trn ng ng dn

hc: tn tht p lc cc b, m

hf: tn tht qua thit b phn phi, m

H: chiu cao hu ch ca b iu ho, H = 4 m



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Tng tn tht hd v hc thng khng vt qu 0,4m, tn tht hf khng vt

qu 0,5m, do p lc cn thit l:

Htc = 0,4 + 0,5 + 4 = 4,9 mH2O = 0,49 at

Cng sut my thi kh tnh theo cng thc sau:

0,283

2

1

. .1

29,7. .

G R T P P

n P

=

Trong :

+ P: Cng sut yu cu ca my (KW)

+ G: trng lng dng kh(Kg/s)

G = qk .kh = 0,042.1,29 = 0,054 (Kg/s)

+R: hng s kh. R = 8,314 (KJ/K.mol.oK )+ T: nhit tuyt i ca khng kh u vo:

T1= 273 + 25 = 298 oK

+ P1 : p lc tuyt i ca khng kh u vo, P1 = 1at

+ P2: p lc tuyt i ca khng kh u ra, P2 =Htc + 1at = 1,49 at

+1 1,395 1

0,2831,395

kn

k

= = = ( k = 1,395 i vi khng kh).

+ 29,7: h s chuyn i.

+: hiu sut ca my nn kh, = 0,7 0,9, chn = 0,8.

0,2830,054.8,314.298 1, 49

1 2, 4( )29,7.0,283.0,8 1

P KW = =

Cng sut ca my thi kh l 2,4KW.

Tnh ton cc ng dn nc vo v ra khi b iu ho:

Nc thi c bm t ngn tip nhn vo b iu ho, chn vn tc nc vo b

l 0,7 m/s, lu lng nc thi 55,56m3/h, ng knh ng vo l:

4 4.55,560,168( )

. .3600 .0,7.3600vQ

D mv

= = =

Chn ng nha PVC c ng knh 160

Chn vn tc nc ra khi b l 1m/s, ng knh ng dn nc ra:

4.20,830,086( ).1.3600

rD m= =

Chn ng nha PVC c ng knh 90.



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Tnh bm bm nc thi


. . . 1000.9,81.8.20,830,57( )

1000 1000.0,8.3600

g H QN kW

= = =

Vi:Q : lu lng nc thi (m3/s).



: hiu sut bm (%). Chn = 0,8.


NTT = 1,2.N = 1,2.0,57 = 0,7 (kW)

Chn 2 bm cng sut 0,7 kW, 1 bm hot ng v 1 bm d phng

Tng hp tnh ton b iu ho

Thng s Gi tr

Chiu di, L(m) 7

Chiu rng, B(m) 6

Chiu cao, H(m) 4,3

S a khuych tn kh, n(a) 30ng knh ng dn kh chnh, D(mm) 75



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ng knh ng nhnh dn kh, dn(mm) 32

ng knh ng dn nc vo b (mm) 160

ng knh ng dn nc ra khi b (mm) 90

Cng sut my nn kh, N(kW) 2,4

4.5. B lng t I4.5. B lng t I

4.5.1. Nhim v

Nhim v ca b lng t I l loi b cc tp cht l lng cn li trong nc thi

sau khi qua cc cng trnh x l trc . y cc cht l lng c t trng ln

hn t trng ca nc s lng xung y.4.5.2. Tnh ton

Gi s sau li chn rc, b lng ct, b iu ha, hm lng cht rn gim

khong 25%. Nng SS vo b lng I l 461 mg/l.

Hiu qu kh SS ca b lng I t 60%. Vy hm lng cn l lng ra khi b

lng I l 184 mg/l.

Chn b lng t I c dng hnh trn trn mt bng, nc thi vo t tm v thu

nc theo chu vi b (b lng ly tm).

Cc thng s c bn thit k cho b lng t I

Thng s Gi trTrong khong c trng

Thi gian lu nc, giTi trng b mt, m3/m2.ngy

Lu lng trung bnh

Lu lng cao im

Ti trng mng trn, m3/m.ngy

ng trung tm

ng knh

Chiu cao

1.5 2.5

32 48

80 120

125 - 500

15 20% D

55 65% H

3.0 4.6

2.0

102

248

3.6



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Chiu su H ca b lng, m

ng knh D ca b lng, m

dc y b, mm/m

Tc thanh gt bn, vng/pht

3.0 60

62 167

0.02 0.05

12 45

83

0.03

Din tch b mt ca b lng ly tm trn mt bng c tnh theo cng thc:

2500 15,625( )32A

QA m

L= = =

Trong :

Q:lu lng nc thi (m3/ng).

LA: ti trng b mt, chn LA = 32 (m3/m2.ngy)

ng knh b lng:

4 4. .15,625 4,46( )D A m

= = =

ng knh ng trung tm:

d = 20%D = 20%.4,46 = 0,9 (m)

Chn chiu su hu ch ca b lng H=3m, chiu cao lp bn lng hb=0,7m, chiu

cao lp trung ho hth= 0,2m, chiu cao bo v hbv= 0,3m. Vy chiu cao tng cng

ca b lng t I l:

Htc = H + hb + hth + hbv = 3 + 0,7 + 0,2 + 0,3 =4,2 (m)

Chiu cao ng trung tm:

h = 60%H = 60%.3= 1,8 (m)

Kim tra thi gian lu nc ca b lng:

Th tch b lng:

2 2 2 2 3( ). (4, 46 0,9 ).3 45( )4 4

W D d H m = = =

Thi gian lu nc:

45.242,16( ) (1,5 2,5)

500

Wt h

Q= = = tho mn

Ti trng b mt:

Ls =Q

D=

50035,68

.4,46= (m3/m.ngy)

Ls < 500m3/m.ngy tho mn



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Gi s hiu qu x l cn l lng t 60% ti trng 32m3/m2.ngy. Lng bn

ti sinh ra mi ngy l:

Mti = 461gSS/m3.500m3/ngy.0,6/1000g/kg = 138,3 (kgSS/ngy)

Gi s nc thi c hm lng cn 5% ( m 95%), t s VSS : SS = 0,8 v

khi lng ring ca bn ti = 1,053kg/l. Vy lu lng bn ti cn phi x l l:

Qti =138,3 / 1

.0, 05.1, 053 / 1000

kg ngay

kg l= 2,63 (m3/ngy)

Lng bn ti c kh nng phn hu sinh hc:

Mti (VSS)= 138,3 kgSS/ngy.0,8 = 110,64 (VSS/ ngy)

Mng thu nc

Mng thu nc t vng trn, c ng knh bng 0,8 ng knh b:

Dm = 0,8.D = 0,8.4,46 = 3,57 (m)

Chiu di mng thu nc:

Lm = Dm = .3,57 = 11,2 (m)

Chiu cao mng hm = 0,5m

Mng b tng ct thp dy 100mm, c lp thm mng rng ca thp tm khng g

c dng ch V, gc 900C.

Tnh bm bn n b nn bn : bm 10 pht/ngy



41/70


N =1008.9,81.10.0,004

0,5( )1000 1000.0,8

gHQkW

= =

Trong :

Q : lu lng bn bm n b nn bn (m3/s).

H : chiu cao ct p ton phn. H = 10 (mH2O).

: khi lng ring ca bn (kg/m3).= 1008 kg/m3.

: hiu sut bm (%). Chn = 0,8.


NTT = 1,2.N = 1,2.0,5 = 0,6 (kW)

Chn 2 bm cng sut 0,6 kW hot ng lun phin nhau bm bn n b nn

bn.

Tnh bm t b lng I sang b UASB


N =1008.9,81.6.20,83

0,43( )1000 1000.0,8.3600

gHQkW

= =

Vi:

Q : lu lng nc thi (m3/s).



: hiu sut bm (%). Chn = 0,8.


( )1, 2 1, 2 0, 43 0,52TTN N kW= = =

Chn 2 bm cng sut 0,52 kW, 1 bm hot ng v 1 bm d phng.

Tng hp tnh ton b lng t I

Thng s Gi tr



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ng knh b lng, D(m) 4,46Chiu cao b lng, H(m) 4,2ng knh ng trung tm, d(m) 0,9Chiu cao ng trung tm, h(m) 1,8

Kch thc mng

ng knh mng thu nc, m 3,57

Chiu di mng thu nc, m 11,2Chiu cao mng thu nc, m 0,5

Lng bn ti sinh ra mi ngy, Mti(kgSS/ngy) 138,3Lu lng bn ti cn x l, Qti(m3/ngy) 2,63

4.6. B UASB4.6. B UASB

4.6.1. Nhim v

Lm gim ng k hm lng COD, BOD trong nc thi bng cch s dng lpcn l lng (c cha rt nhiu vi sinh vt ym kh) trong dch ln men nh h thng

nc thi chy t pha di ln. ng thi to thun li cho qu trnh x l hiu kh

trong b aerotank.

4.6.2. Tnh ton

Gi s sau cc cng trnh x l s b hiu qu x l t c:

ECOD = 20%

EBOD = 20%Cc thng s u vo:

Lu lng Q=500 m3/ng.

BOD5 = 2254 mg/l

COD = 4168 mg/l

SS = 184 mg/l

Cc thng s u ra:

BOD5 = 451 mg/l (EBOD = 80%)

COD = 834 mg/l (ECOD = 80%)

SS = 147 mg/l (ESS = 20%)

Dung tch phn x l k kh cn thit:

. 500.4168260,5

8.1000COD

Q CV

L= = = (m3)

Trong :C: Hm lng COD u vo (mg/l).



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LCOD: Ti trng th tch. LCOD = 8kgCOD/m3.ngy. (Bng 10 10, XLNT

th v cng nghip, Lm Minh Trit).

Din tch b mt b UASB:

2500 41,66( )

12A

QF m

L

= = =

Vi: LA : Ti trng b mt phn lng, L = 12 m3/m2.ngy. (Bng 10 9,

XLNT th v cng nghip , Lm Minh Trit).

Chia b thnh 2 n nguyn hnh vung, vy cnh mi n nguyn l:

41,664,56( )

2

FW m

n= = =

Chiu cao phn x l k kh:

1

260.56,25( )

41,66

VH m

F= = =

Tng chiu cao ca b l:

H = H1 + H2 + H3

Trong :

H1: chiu cao phn x l k kh.

H2: chiu cao phn lng, chn H2 = 1,5m.

H3: chiu cao bo v, H3 = 0,3m.

Chiu cao b:

H = 6,25 + 1,5 + 0,3 = 8,05(m)

Chn H = 8m.

B tr mi n nguyn 2 phu thu kh. Mi phu c chiu cao 1,5m. y phu thu

kh c chiu di bng cnh n nguyn: l = W = 4,56m v chiu rng W = 1,9m.

Vy phn din tch b mt khe h gia cc phu thu kh l:4,56.4,56 2.4,56.1,9

.100 .100 16,67%4,56.4,56

pkhA AA

A A

= = =

Gi tr ny nm trong khong Akh/A = 15 20%

Trong :

A: Din tch b mt b

Akh: Din tch khe h gia cc phu thu kh

Ap: Din tch y phu thu kh

Tnh h thng phn phi nc:



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B tr mi n nguyn 10 ng phn phi nc vo, din tch trung bnh cho 1 u

phn phi l:

4,56.4,562,1

10na = = m2/u [2 5 m2/u]

Lng bn nui cy ban u cho vo b ( TS = 5% ). 30.260,5

156,30,05.1000

SSb

C VM

TS= = = (tn)

Trong :

Css: Hm lng bn trong b. Css = 30 kg/m3 (Theo X l nc thi th v

cng nghip, Lm Minh Trit).

TS: Hm lng cht rn trong bn nui cy ban u.

Hm lng COD ca nc thi sau x l k kh:

CODra = (1 ECOD).CODvo = (1 0,8).4168 = 834 mg/l

Hm lng BOD5 ca nc thi sau x l k kh:

BOD5 = (1 EBOD).BODvo = (1 0,8).2254 = 451 mg/l

Lng sinh khi hnh thnh mi ngy:

( )01

x

d c

Y S S QP

k

=+

Trong :

Y: h s sn lng sinh t bo, Y = 0,04 g VSS/g COD

kd: h s phn hy ni bo

c : thi gian lu bn (35 100 ngy), chn c = 90 ngy

S0, S: lng COD u vo v u ra b

Th tch kh metan sinh ra mi ngy CH4

[ ]4 0

159 ( ) 1,42CH xV S S Q P =

4

(4168 834).500350,84 1,42.28,4

1000CHV

=

= 570701 (l/ngy) = 507,1(m3/ngy)

Trong :

4CHV : th tch kh metan sinh ra iu kin chun ( nhit 0 0C v p sut

1atm)Px: lng sinh khi sinh ra mi ngy (kgVS?ngy)



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350,84: h s chuyn i l thuyt lng kh metan sn sinh t 1kg BOD L

chuyn thnh kh metan v CO2 (lit CH4 / kg BODL)

Lng bn d bm ra mi ngy:

28,41,26

0,75. 0,75.30

xw

ss

PQ

C= = = (m3/ngy)

CSS: hm lng bn trong b (kg/m3)

Lng cht rn t bn d:

MSS = Qw.CSS = 1,26.30 = 37,8 (kg SS/ngy)

Tnh cc ng phn phi nc vo b UASB:

Vn tc nc chy trong ng chnh v = 0,8 - 2m/s, chn v = 1m/s.

D = 4. .24.3600

Qv

= 4.500.1.24.3600

= 0,086 (m)


T ng chnh chia lm 2 ng nhnh vo 2 n nguyn.Vn tc nc chy

trong ng nhnh v = 0,8 - 2m/s, chn v = 1m/s.

Dn =4 / 2

. .24.3600

Q

v=

4.500/ 2

.1.24.3600= 0,06 (m)


4.7. B aerotank4.7. B aerotank

4.7.1. Nhim v

B aerotank c ng dng kh ph bin trong cc qu trnh x l hiu kh.

Mc ch ch yu ca qu trnh ny l da vo hot ng sng v sinh sn ca vi

sinh vt n nh cht hu c lm keo t cc ht cn l lng khng lng c. Ty

thuc vo thnh phn nc thi c th, Nit v Photpho s c b sung gia tng

kh nng phn hy ca vi sinh vt.

* Cc iu kin, yu cu v cc yu t mi trng nh hng n qu trnh x l:

- iu kin u tin: cung cp oxi v lin tc cho b sao cho lng DO ra

khi b lng II khng nh hn 2 mg/l.

- Nng cho php cc cht bn hu c: nu c nhiu cht bn trong nc thi

s ph hy ch hot ng sng bnh thng ca vi sinh vt trong nc thi, gy

"qu ti" v nu c nhiu cht c hi s gy "sc" vi sinh vt. V vy, nu nc thi

c nhiu cht bn th phi pha long trc khi x l.



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- Lng cc nguyn t dinh dng cn thit cho qu trnh sinh ha din ra bnh

thng cn nm trong gii hn cho php: N, P, K, Ca, S, P,...C th chn theo t l

sau:

BODton phn : N : P = 100 : 5 : 1

hay COD : N : P = 150 : 5 : 1

4.7.2. Tnh ton

Cc thng s thit k nh sau:

Lu lng nc thi : Q = 500 m3/ ngy m.

Hm lng BOD5 trong nc thi dn vo aeroten l 451 mg/l.

Hm lng BOD5 trong nc thi u ra l 90 mg/l.

Chn aerotank kiu xo trn hon ton tnh ton thit k. Cc thng s c bn

tnh ton :

Thi gian lu bn : 155 =c ngy

T s F/M : 0,2 0,6 kg/kg.ngy

Ti trng th tch : 0,8 1,92 kgBOD5/m3.ngy

Nng MLVSS : 2500 4000 mg/l

T s tun hon bn hot tnh : Qth/Q = 0,25 1

Gi s kt qu thc nghim tm c cc thng s ng hc nh sau:

H s sn lng bn : Y = 0,5 mgVSS/mgBOD5.

H s phn hu ni bo : kd = 0,06 ngy-1.

p dng cc s liu sau dng tnh ton:

T s gia lng cht rn l lng d bay hi (MLVSS) vi lng cht rn

l lng (MLSS) c trong nc thi l 0,8 (MLVSS/MLSS = 0,8)

Nng bn hot tnh tun hon (tnh theo cht rn l lng) l 10000mg/l.

Hm lng cht l lng d bay hi (MLVSS) trong hn hp bn hot tnh

b aerotank X = 3800mg/l.

Hm lng bn hot tnh trong b aerotank:



47/70


MLSS =3800

4750 / .0,8 0,8

MLVSSmg l= =

Nc thi u ra cha 60mg/l cn sinh hc, trong c 65% cn d phn

hu sinh hc.

Tnh kch thc b aerotank

Xc nh nng BOD5 ho tan trong nc u ra theo cng thc:

BOD5 u ra = BOD5 ha tan i ra t b aerotank + BOD5 cha trong lng cn

l lng u ra.

Phn c kh nng phn hu sinh hc ca cht rn sinh hc u ra l:

60.0,65mg/l = 39mg/l

Lng oxy cn cung cp oxy ho ht lng cn ny c tnh da vo

phng trnh phn ng:

C5H7O2N + 5O2 5CO2 + 2H2O + NH3 + nng lng

113mg160mg

1mg 1,42mg

(lng oxy cung cp ny chnh l BOD20 ca phn ng)

Vy BOD hon ton ca cht rn c kh nng phn hu sinh hc u ra l:

39 x 1,42 (mgO2 tiu th/mg t bo b oxy ho) = 55mg/l

BOD5 ca cn l lng ca nc thi sau b lng II l:

BOD5 = 0,68 BOD20 = 0,68 x 55= 37 mg/l

BOD5 ho tan trong nc u ra xc nh nh sau:90 mg/l = BOD ht5 + 37mg/l

BODht5 = 53mg/l

Xc nh hiu qu x l E:

Hiu qu x l c xc nh theo phng trnh sau:

E =0

0

.100S S

S

Hiu qu x l tnh theo BOD5 ho tan:



48/70


E =451 53

.100 88%451

=

Hiu qu x l tnh theo BOD5 tng cng:

Etc =451 90

100 80%451

=

Th tch b aeroten c tnh theo cng thc sau:

V=30. . .( ) 500.10.0,5(451 53) 163

.(1 . ) 3800(1 0,06.10)c

d c

Q Y S S m

X k

= =

+ +

Trong :

c : thi gian lu bn, theo quy phm 5 15 ngy, chn c = 10ngy

Q : lu lng trung bnh ngy, Q = 500m3/ngy

Y : h s sn lng bn, Y = 0,5 mgVSS/mg BOD5

S0: hm lng BOD5 dn vo aerotank, S0 = 451mg/l

S: hm lng BOD5 ho tan ca nc thi dn ra khi aerotank,

S = 53mg/l.

X : nng cht l lng d bay hi trong hn hp bn hot tnh,

X = 3800 mg/l.

kd: h s phn hu ni bo, chn kd = 0.06 ngy-1.

Xc nh thi gian lu nc ca b aeroten:

163.24 7,8( )

500

Vh

Q = = =

Xc nh kch thc b aeroten:

Cc kch thc in hnh ca aerotank xo trn hon ton

Thng s Gi trChiu cao hu ch, (m) 3.0 4.6Chiu cao bo v, (m) 0.3 0.6Khong cch t y n u khuych tn kh, (m) 0.45 0.75T s rng : su ( W: H) 1 : 1 2.2 : 1

Chn chiu cao hu ch ca b l 3,5m, chiu cao bo v l 0,5m.

Vy chiu cao tng cng ca b: H = 4m.Chiu di ca aerotank l L = 9m.



49/70


Chiu rng b aerotank l W = 5,2m.

Kch thc b aerotank: L x W x H = 9 x 5,2 x 3,5

Tnh ton lu lng bn thi b mi ngy:

Gi s bn d c x b (dn n b nn bn) t ng ng dn bn tun hon

v hm lng cht rn l lng d bay hi (MLVSS) trong bn u ra chim 80%

hm lng cht rn l lng (MLSS). Khi lu lng bn d thi b c tnh da

vo cng thc:

.

.c

w r c c

V X

Q X Q X

=+

Trong : V : th tch aerotank, V = 163m3

X : nng MLVSS trong hn hp bn hot tnh b aerotank,

X = 3800mg/l.

Qw: lu lng bn thi, m3.

Xr: nng MLVSS c trong bn hot tnh tun hon

Xr= 0,8.10000 = 8000 mg/l

Qc: lu lng nc thi ra khi b lng II, Qc = Q = 500m3/ngy.

T tnh c:

Qw=. . . (163.3800) (10.500.48)

4,7. 10.8000

c c c

c r

V X Q X

X

= = (m3/ngy)

Tnh h s tun hon

T phng trnh cn bng vt cht vit cho b lng II (xem nh lng cht hu

c bay hi u ra ca h thng l khng ng k), ta c:



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( )rr r r w

X Q Q X Q X Q+ = +

Lu lng bn tun hon:

3800.500 8000.4,7443

8000 3800r w

rr

XQ X QQ

X X

= = =

(m3/ng)

Vy, ta c:

4430,88

500rQ

Q = = =

Kim tra t s F/M v ti trng hu c:

T s F/M xc nh theo cng thc sau:

0

4510,2. 3800.7,8

SF

M X= = = (ngy-1)

Ti trng th tch:

3 30. 451.500.10 .10 1,4163

S QL

V = = = ( kgBOD5/m3.ngy)

C hai gi tr ny u nm trong gi tr cho php i vi aerotank xo trn

hon ton:

F/M = 0,2 0,6

LBOD= 0,8 1,9

Tnh lng oxy cn thit cn cung cp cho aerotank da trn BOD20

H s to bn t vic kh BOD5

Yobs=0,5

0,3125( / )1 . 1 0,06.10d c

Ymg mg

k = =

+ +

Lng sinh khi gia tng mi ngy tnh theo MLVSS:

v o. .( )x obs raP Y Q BOD BOD=

0,3125.500.(451 53)

62,2( / )1000

kgVSS ngay

= =

Lng oxy cn thit trong iu kin tiu chun:

OCo= xo P

f

gkgSSQ42,1

)/(10)..( 3

=

3500.(451 53).101,42.62,2 204,30,68

= (kgO2/ngy)

Trong :



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Q : lu lng nc thi , Q = 500m3/ngy.

So: BOD5 ca nc thi u vo

S : BOD5 ca nc thi u ra

f : h s chuyn i BOD5 sang BOD20, f = 0,68

1,42: h s chuyn i t bo sang BOD.

Px: Lng sinh khi gia tng mi ngy tnh theo MLVSS

Lng oxy cn thit trong iu kin thc t:

2

9,08203,4 262 / ng y

9,08 2S

t oS L

COC OC kgO

C C= = =

Trong :

CS : nng bo ha ca oxy trong nc nhit lm vic, CS = 9,08 mg/l.

CL: lng oxy ha tan cn duy tr trong b, CL = 2mg/l

Trong khng kh, oxy chim 21% th tch. Gi s rng trng lng ring ca

khng kh l 1,2kg/m3. Vy lng khng kh l thuyt cho qu trnh l:

2262

10390,21.1,2 0,21.1,2

Okk

MQ = = = (m3/ngy)

Gi s hiu qu vn chuyn oxy ca thut b thi kh l 8%, h s an ton khi s

dng trong thit k l 1,5. Vy lng kh theo yu cu l:19481.1,5

194810,08k

Q = = (m3/ngy) = 0,225 (m3/giy)

Tnh h thng phn phi kh

Chn a phn phi kh dng a xp ng knh 170mm, din tch b mt F =

0,02m2.

Lu lng ring phn phi kh ca a thi kh = 150 200 l/pht, chn =

200 l/pht.Lng a thi kh trong b aerotank:

N =3 3 310 . ( / ) 10 *19481

6724.60. ( / ) 24*60*200

kkQ m ngay

l phut = =

(a)

thun li cho vic b tr ta chn s a thi kh l 60 a.

Phn phi a thnh hng 10 hng theo chiu di b, mi hng 6 a.

Lu lng khng kh cn kh 1kg BOD5:

Lu lng kh cp cho 1m3 nc thi:



52/70


C =19481

38,9500

kkQ

Q= = (m3/m3)

Lu lng khng kh cn kh 1kg BOD5:

5

3 3

1948197,9

( ).10 500.(451 53).10

BOD kkkk

o

Qq

Q S S = = =

(m3kh/kgBOD5)

Trong : Q : lu lng nc thi.

Qkk : th tch khng kh.

So : BOD5 trong nc thi u vo

S : BOD5 trong nc thi u ra

Tnh ton my thi kh

p lc cn thit cho h thng ng nn kh c xc nh theo cng thc:Htc = hd + hc + hf+ H = 0,4 + 0,5 + 3,5 = 4,4 (m)

Trong :

hd, hc: tn tht p lc dc theo chiu di ng v tn tht cc b ti cc

im un , khc quanh (m), Tng tn tht hd v hc khng vt

qu 0,4m.

hf : tn tht qua cc a phn phi (m), gi tr ny khng vt qu

0.5m.H : chiu cao hu ch ca b aerotank, H = 3,5m.

Cng sut my thi kh tnh theo cng thc sau:

0,283

2

1

. .1

29,7. .

G R T P P

n P

=

Trong :

+ P: Cng sut yu cu ca my (KW)+ G: trng lng dng kh(Kg/s)

G = Qk . kh = 0,225.1,29 = 0,29 (Kg/s)

+R: hng s kh. R = 8,314 (KJ/K.mol.oK )

+ T: nhit tuyt i ca khng kh u vo:

T1= 273 + 25 = 298 oK

+ P1 : p lc tuyt i ca khng kh u vo, P1 = 1at

+ P2: p lc tuyt i ca khng kh u ra, P2 =Htc + 1at = 1,44 at



53/70


+1 1, 395 1

0,2831,395

kn

k

= = = ( k = 1,395 i vi khng kh).

+ 29,7: h s chuyn i.

+: hiu sut ca my nn kh,= 0,7 0,9, chn = 0,8.

Vy cng sut ca my nn kh l:0,283

0,29.8,314.298 1,441 11,6( )

29, 7.0, 283.0,8 1wP kW

= =

Chn 2 my thi kh cng sut 11,6KW, mt hot ng, mt d phng.

Chn ng ng dn kh

ng dn kh chnh:

Dchnh= 4 .kQv = 4.0,225.14 =0,14 (m) = 140 (mm)

Trong :

Qkhi: lu lng kh ng chnh.

v : vn tc kh trong ng chnh, v = 10 15 m/s, chn v =14m/s

Chn ng thp khng g ng knh =140mm.

ng dn kh nhnh:

dn =v

Qn.

4

= 4.0,0225.12

=0,049 (m) = 49mm..

Trong :

Qn: lu lng kh trn ng nhnh

Qn = Qkhi/n = 0,225/10 = 0,0225 (m3/s)

n : s hng phn phi a sc kh

v : vn tc kh, chn v =12m/s

Chn ng thp khng g ng knh = 50mm.

Tnh ng dn nc thi v ng dn bn tun hon

ng dn nc thi vo:

Chn vn tc nc thi chy trong ng: v = 0,7m/s

ng knh ng dn l:

D =4.

. .3600.24

Q

v = 0,102 (m) = 102 (mm)

Chn ng nha PVC ng knh ng = 110mm.



54/70


ng dn nc thi ra:

Chn vn tc nc thi chy trong ng v = 0,7m/s

Lu lng nc thi : Q + Qr = 500 + 443 = 943 (m3/ngy)

ng knh ng l:

D =4.( )

24.3600. .

Q Qr

v

+=

4.943

24.3600.0,7.=0,14 (m) = 140 (mm)

Chn ng nha PVC c ng knh =140mm.

ng dn bn tun hon:

Chn vn tc bn chy trong ng: v = 1m/s

Lu lng tun hon : Qr = 443m3/ng

ng knh ng dn l:

D =4.

24.3600. .

Qr

v =

4.443

24.3600.1.3,14= 0,08 (m) = 80 (mm)

Chn ng nha PVC ng knh ng = 80

Bng tng hp tnh ton b aerotank

Thng s Gi tr

Th tch b: di x rng x cao 9m x 5,2m x 4mLu lng bn thi Qw (m3/ngy) 4,7

T s tun hon bn, 0,88

Lu lng bn tun hon, Qr(m3/ngy) 443

Thi gian lu nc, (h) 7,8

Lng khng kh cn, Qkk(m3/ngy) 19481

Lng khng kh cn kh 1kg BOD5, qkk(m3/kgBOD5)

97,9

S a s khuych tn kh, N (a) 70

ng knh ng dn kh chnh, D(mm) 140

ng knh ng dn kh nhnh, d(mm) 50

Cng sut my cp kh, (kW) 11,6

4.8. B lng II4.8. B lng II



55/70


4.8.1. Nhim v

Nc thi sau khi qua b Aerotank s c a n b lng II, b ny c nhim v

lng cc bng bn hot tnh t b Aerotank a sang. Mt phn bn lng s c

tun hon tr li b Aerotank, phn bn d c thi ra ngoi.

4.8.2. Tnh ton

Chn b lng t II l b lng ly tm.

Cc thng s thit k c trng cho b lng t II vi bn hot tnh khuych tn

bng khng kh nh sau:

Ti trng b mt, m3/m2.ngy

o Trung bnh : 16,3 32,6

o Ln nht : 40,7 48,8

Ti trng cht rn, kg/m2.h

o Trung bnh : 3,9 5,9

o Ln nht : 9,8

Chiu cao cng tc,m : 3,7 6,1

Chn ti trng b mt thch hp cho bn hot tnh ny l 20m3/m2.ngy v titrng cht rn l 5,5kg/m2.h

Din tch b mt b lng theo ti trng b mt:

AL =2500 25( )

20A

Qm

L= =

Trong :

Q : lu lng trung bnh ngy, m

3

/ngyLA: ti trng b mt, m3/m2.ngy

Din tch b mt b lng tnh theo ti trng cht rn l:

AS =2( ) (500 443).4750 33,9( )

24.5,5.1000r

S

Q Q MLSS m

L

+ += =

Trong :

Qr: lu lng bn tun hon, m3/ngy

LS: ti trng cht rn, kgSS/m2.ngy



56/70


Do AL>AS, vy din tch b mt lng tnh theo ti trng b mt l din tch tnh

ton.

ng knh b lng:

D = A.4

=

4.33,9

= 6,6 (m)

ng knh ng trung tm:

d = 20%D = 20%.6,6 = 1,3 (m)

Chn chiu cao hu ch ca b lng l hL= 3m, chiu cao lp bn lng hb=

1,5m v chiu cao bo v hbv= 0,3m. Vy chiu cao tng cng ca b lng II:

Htc = hL + hb + hbv = 3 + 1,5 + 0,3 = 4,8 (m)Chiu cao ng trung tm;

h = 60%hL = 60%.3,2 = 1,92 (m)

Thi gian lu nc ca b lng:

+ Th tch phn lng:

VL =2 2 2 2 3( ). (6,6 1,3 ).3 98,65( )

4 4LD d h m

= =

+ Thi gian lu nc:

t =98,65.24

2,5( )500 443

L

r

Vh

Q Q= =

+ +

Th tch b cha bn:

Vb = A.hb = 33,9.1,5 = 50,85 (m3)

Thi gian lu gi bn trong b:

tb =50,85.24

2,72( )

(4,7 443)

b

w r

Vh

Q Q

= =

+ +Ti trng b mt:

LS =(500 443)

46,2.6,5

rQ Q

D

+ += = (m3/m.ngy)

Gi tr ny nm trong khong cho php LS < 500 m3/m.ngy

Mng thu nc

Mng thu nc t vng trn, c ng knh bng 0,8 ng knh b:



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Dm = 0,8.D = 0,8.6,5=5,2 (m)

Chiu di mng thu nc:

Lm = Dm = .5,2 = 16,33 (m)

Chiu cao mng hm = 0,5m

Mng b tng ct thp dy 100mm, c lp thm mng rng ca thp tm khng g

c dng ch V, gc 900C.

Tnh ng dn nc thi v ng dn bn

ng dn nc thi vo:

Chn vn tc nc thi chy trong ng: v = 0,7m/s

Lu lng nc thi vo b:

Qv = Q+ Qr = 500 + 443 = 943 (m3/ngy)

D =4.

24.3600. .VQ

v =

4.943

24.3600.0,7.= 0,14 (m) = 140 (mm)

Chn ng nha PVC ng knh ng = 140mmng dn nc thi ra:

Chn vn tc nc thi chy trong ng v = 0,7m/s

Lu lng nc thi : Q = 500m3/ng

ng knh ng l:

D =4.

24.3600. .

Q

v =

4.500

24.3600.0,7.= 0,1(m) = 100 (mm)

Chn ng nha PVC c ng knh = 100mm

ng dn bn:

Chn vn tc bn chy trong ng: v = 1m/s

Lu lng bn: Qb = Qr+ Qw = 4,7 + 443 = 447,7 (m3/ngy)

ng knh ng dn l:

D =4.

24.3600. .bQ

v =

4.447,7

24.3600.1.= 0,08 (m) = 80 (mm)

Chn ng nha PVC ng knh ng = 80mm.



58/70


Tnh bm bn tun hon

N =1008.9,81.10.443

0,63( )1000 1000.0,8.24.3600

gHQkW

= =

Vi:

Q : lu lng bn tun hon (m3/s).H : chiu cao ct p ton phn. H = 10 (mH2O).

: khi lng ring ca bn, = 1008 (kg/m3).

: hiu sut bm (%).


NTT = 1,2.N = 1,2.0,63 = 0,76(kW)

Tnh bm bn n b nn bn

Thi gian bm 15 pht/ngy.

N =1008.9,81.10.0,005

0,65( )1000 1000.0,8

gHQkW

= =

Vi:Q : lu lng bn x ra (m3/s).


: khi lng ring ca bn, = 1008 (kg/m3).

: hiu sut bm (%).


NTT = 1,2.N = 1,2.0,65 = 0,78 (kW)

Chn 2 bm cng sut 0,78 kW hot ng lun phin nhau .

Tng hp thit k b lng t II

Thng s Gi trng knh b lng , D(m) 6,5

Chiu cao b lng, H(m) 4,8ng knh ng trung tm, d(m) 1,3Chiu cao ng trung tm, h(m) 1,92



59/70


Thi gian lu nc, t(h) 2,5Thi gian lu bn, tb(h) 2,72ng knh ng dn nc thi vo (mm) 140ng knh ng dn nc thi ra (mm) 100ng knh ng dn bn (mm) 80

4.9. B nn bn4.9. B nn bn

4.9.1. Nhim v

Cn ti t b lng t I v bn hot tnh t b lng II c m tng i cao(92 96% i vi cn ti v 99,2 99,7% i vi bn hot tnh) nn cn phi gim

m v th tch trc khi a vo cc cng trnh pha sau. Mt phn ln bn t b

lng II c dn tr li aerotank (loi bn ny c gi l bn hot tnh tun hon),

phn bn cn li c gi l bn hot tnh d c dn vo b nn bn. Nhim v

ca b nn bn l lm gim m ca bn hot tnh d bng cch lng (nn) c hc

t m thch hp (95 97%) phc v cho cc qu trnh x l bn pha sau.

B nn bn tng i ging b lng ly tm. Ti y bn c tch nc gim

th tch. Bn long (hn hp bn - nc) c a vo ng trung tm tm b. Di

tc dng ca trng lc bn s lng v kt cht li. Sau khi nn bn s c rt ra khi

b bng bm ht bn.

4.9.2. Tnh ton

Lu lng bn d cn x l mi ngy:

QV = QI + QUASB + QII = 2,63 + 1,26 + 4,7 = 8,59 (m3/ngy)

Din tch ca b nn bn ng c tnh da theo cng thc:

F =3

23 2

8,59 /1,19( )

0,3 / . .24 /V

o

Q m ngaym

q m m h h ngay= =

Trong :

qo: Ti trng tnh ton ln din tch mt thong ca b nn bn (m3/m2.h), qo=

0,3 m3/m2.h

ng knh ca b nn bn :



60/70


D =4F

=

4.1,19

= 1,23 (m)

ng knh ng trung tm:

d = 0,1D = 0,1.1,23 = 0,123m

ng knh phn loe ca ng trung tm:

d1 = 1,35d = 1,35.0,123 = 0,17 (m)

ng knh tm chn:

dch= 1,3d1 = 1,3.0,17 = 0,22 (m)

Chiu cao cng tc ca b nn bn :

H = qo.t = 0,3.10 = 3m

Vi t : thi gian nn bn. Chn t = 10h quy phm (10 12h).

Chiu cao tng cng ca b nn bn :

Htc = H + h1 + h2 + h3 = 3 + 0,3 + 0,3 + 0,8 = 4,4 (m)

Trong :

h1: chiu cao t mc nc n thnh b (m).

h2: chiu cao lp bn (m)

h3: chiu cao phn chp y b (m)

Mng thu ncMng thu nc t vng trn theo thnh b, cch thnh b 0,3m.

ng knh mng thu nc:

Dm = 0,8D = 0,8.1,23 = 0,98 (m)

Chiu di mng thu nc:

Lm = D = .1,23 = 3,86 (m)

Lng nc tch ra khi bn:

99,2% - 97% = 2,2%

Lng bn sau khi nn:

Qb = QV 2,2%QV = 8,59 2,2%.8,59 = 8,4 (m3/ngy).



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Tnh cng sut bm ht bn :

Thi gian ht bn 20 pht, 8h ly bn 1 ln.

N =1200.9,81.8.0,0023

0,3( )1000 1000.0,8

gHQkW

= =

Trong :

Q : lu lng bn sau khi nn (m3/s).


: khi lng ring ca bn sau khi nn (kg/m3).= 1200 (kg/m3).

: hiu sut bm (%). Chn = 0,8.


NTT = 1,2.N = 1,2.0,3 = 0,36 (kW)

Chn 2 bm cng sut 0,36 kW hot ng lun phin nhau .

Tng hp thit k b nn bn

Thng s Gi tr



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Lu lng bn sau khi nn, Qnn(m3/ngy) 8,4ng knh b nn bn, D(m) 1,23ng knh ng trung tm, d(m) 0,123ng knh phn loe ca ng trung tm, dl(m) 0,17ng knh tm chn, dch(m) 0,22

Chiu cao tng cng b nn bn, Htc(m) 4,4

4.10. My p bn4.10. My p bn

4.10.1. Nhim v:

Cn sau khi qua b nn bn c nng t 3 8% cn a qua my p bn

gim m xung cn 70 80%, tc nng cn kh t 20 30% vi mc ch:

- Gim khi lng bn vn chuyn ra bi thi.

- Cn kh d chn lp hay ci to t hn cn t.

- Gim lng nc bn c th thm vo nc ngm bi thi.

- t gy mi kh chu v t c tnh.

4.10.2. Tnh ton:

Lu lng cn n lc p dy ai:

093,097100

2,99100.35,0

100

100.

2

1 =

=

=P

PQQ vb m3/h

Trong :

QV: lng bn a n my p, QV = 8,4m3/ngy = 0,35 m3/h

P1: m ca bn d, P1 = 99,2%

P2: m ca bn sau khi nn b nn bn, P2 = 97%



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Gi s lng bn sau khi nn c C = 50kg/m3, lng cn a n my p bn

l:

Q = C.Qb = 50 kg/m3. 0,093 m3/h = 4,7kg/h =112,8kg/ngy.

My lm vic 6h trong 1 ngy, 1 tun lm vic 3 ngy.Lng cn a n my trong 1 tun: 112,8 . 7 = 789,6kg.

Lng cn a n my trong 1h:

hkgG 87,433.6

789,6==

Ti trng cn trn 1m rng ca bng ti do ng trong khong 90 680kg/m

chiu rng bng gi. Chn bng ti c cng sut 100kg/m rng gi.

Chiu rng bng ti:

mG

b 44,0100

87,43

100===

Chn my c chiu rng 0,5m v nng sut 100kg/m rng gi.

4.11.4.11. H sinh hc thc vtH sinh hc thc vt

4.11.1. Nhim v

Nhim v ca h sinh hc l nhm n nh tnh cht nc thi v tng cng hiu

qu kh cc cht bn hu c cn li trong nc thi. Trong h, nc thi c lm

sch bng qu trnh t nhin nh s c mt ca lc bnh.

4.11.2. Tnh ton

Nc thi sau khi qua b lng II, hm lng BOD5 gim khong 20%.

BOD5 ca nc thi vo h sinh hc l 72mg/l.

Hiu qu x l BOD5 ca h sinh hc l 60%. Nh vy, hm lng BOD5 ca

nc thi ra khi h sinh hc l 28,8mg/l (t tiu chun loi B)

Din tch ca h sinh hc c xc nh:

2( ) (72 28,8)500 0,12( ) 1200( )1000. 1000.180

a tL L QF ha mOM

= = = =



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Trong :

La: BOD5 ca nc thi u vo (mg/l).

Lt: BOD5 ca nc thi u ra (mg/l).

Q: lu lng nc thi (m3/ng)

OM: ti trng b mt (kgBOD5/ha.ngy), c th ly 150 350

kgBOD5/ha.ngy ph thuc vo iu kin nhit , lng nng. Chn OM =

180 kgBOD5/ha.ngy.

Th tch ca h:

W = F.H = 1200.0,8 = 960 (m3)

Trong : H: Chiu cao hu ch ca h (m3). Chn H = 0,8 m.

Chiu cao d tr khi tri ma l 0,3 m.

Chiu cao tng cng ca h l H = 1,1m.

Thi gian lu nc trong h:

960.2446( )

500

Vt h

Q= = =

Chn chiu di ca h sinh hc l: L = 40m.

Chiu rng ca h sinh hc l B = 30m.

Kch thc h sinh hc: B x L x H = 40 x 30 x 1,1 (m).



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CHNG 5: TNH KINH TCHNG 5: TNH KINH T

Gi thnh x l nc bao gm:

Chi ph xy dng c bn v thit b (chi ph u t ban u).

Chi ph vn hnh v qun l.

5.1. Chi ph u t ban u

Chi ph xy dng cng trnh

STT Cng trnhTh tch

(m3)

S

lngn v

n gi

(VN/m3)

Thnh tin

(triu ng)

1 Ngn tip nhn 22,13 1 B tng 1,500,000 33,195

2 B lng ct 4,65 2 B tng 1,500,000 13,95

3 B iu ha 59,25 1 B tng 1,500,000 88,875

4 B lng I 24,87 1 B tng 1,500,000 37,305

5 B UASB 54,65 2 B tng 1,500,000 163,95

6 B Aerotank 52,22 1 B tng 1,500,000 78,33

7 B lng II 42,64 1 B tng 1,500,000 63,96

8 B nn bn 7,13 1 B tng 1,500,000 10,695

GV

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