1.Tn n: Thit k h thng x l nc thi nh my dt nhum nng sut

5000 m3/ngy

2. Nhim v:

- Tng quan

- Xc nh c tnh nc thi. La chn cng ngh x l nc thi.

- Tnh ton thit kv khi ton cc cng trnh n v.

- Th hin cc cng trnh n v trn bn v A1.

3. Ngy giao n:

4. Ngy hon thnh nhim v:

H tn gio vin hng dn: Th.S Phm Qunh Thi Sn

TP. H Ch Minh, ngy thng nm 2013

Gio vin hng dn

LI CM N

hon n hc phn ny, bn cnh s c gng ca c nhm l s h tr

ht sc nhit tnh ca cc thy c khoa Cng ngh Ha hc. Em xin by t lng bit

n i vi thy Phm Qunh Thi Sn tn tnh hng dn, gip chng em

hon thnh tt ti n ny.

Tuy c n lc v c gng nht nh nhng vi thi gian thc hin v vn kin

thc cn hn ch, bi n ca chng em cng khng trnh khi sai st, khuyt

im trong khi thc hin, chng em rt mong nhn c s gp ca qu thy c

v cc bn.

Cui cng chng em xin chn thnh cm n.

TP.HCM, ngy 30/03/2013

Nhm sinh vin thc hin

iv

NHN XT CA GIO VIN HNG DN

..................................................................................................................................

.. ................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

Phn nh gi:

thc thc hin: .....................................................................................

Ni dung thc hin: .................................................................................

Hnh thc trnh by: ................................................................................

Tng hp kt qu: ...................................................................................

im bng s:.............................. im bng ch: ..................................

Tp. H Ch Minh, ngy ..... thng ..... nm 2013

Gio vin hng dn

v

NHN XT CA GIO VIN PHN BIN

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

..................................................................................................................................

Phn nh gi:

thc thc hin: .....................................................................................

Ni dung thc hin: .................................................................................

Hnh thc trnh by: ................................................................................

Tng hp kt qu: ...................................................................................

im bng s:.............................. im bng ch: ..................................

Tp. H Ch Minh, ngy ..... thng ..... nm 2013

Gio vin phn bin

vi

MC LC

LI M U .......................................................................................................... 1

CHNG 1: GII THIU V NGNH CNG NGHIP DT NHUM............ 2

1.1. Tng quan v ngnh nhum .......................................................................... 2

1.2. Thnh phn tnh cht thuc nhum .............................................................. 2

1.2.1. Cc loi thuc nhum .................................................................................... 2

1.3. Tnh c ca phm nhum ............................................................................. 5

1.3.1. Tnh c ca phm nhum ............................................................................. 5

1.3.2. nh hng n con ngi v ng vt........................................................... 9

1.4. Cng ngh sn xut v ngun pht sinh nc thi ................................... 10

1.4.1. Cc cht gy nhim chnh trong nc thi ca cng nghip dt nhum bao gm 11

1.5. X l nc thi cng nghip dt nhum ......................................................... 13

1.5.1. Cc phng php ngn nga, gim thiu ..................................................... 14

1.5.2. Cc phng php x l ................................................................................ 14

CHNG 2: THIT K QUY TRNH X L NC THI DT NHUM 16

2.1. C s l thuyt ca qu trnh s l .............................................................. 16

2.1.1. X l nc thi bng phng php c hc............................................... 16

2.1.2. X l bng phng php ha l ................................................................... 16

2.1.3. X l bng phng php ha hc................................................................. 17

2.1.4. X l bng phng php sinh hc ................................................................ 18

2.2. Thit k quy trnh x l nc thi ............................................................... 20

2.2.1. Song chn rc .............................................................................................. 21

2.2.2. B lng ct ................................................................................................... 21

2.2.3. B iu ha lu lng .................................................................................. 21

2.2.4. B lng t I ................................................................................................ 22

vii

2.2.5. B phn ng Aerotank ................................................................................. 22

2.2.6. B lng t II ............................................................................................... 22

2.2.7. B gom bn ................................................................................................. 22

2.2.8. B c c cn ............................................................................................... 23

2.2.9. Thit b kh trng ........................................................................................ 23

2.2.10. Sn phi bn .............................................................................................. 23

CHNG 3: TNH TON THIT B CHNH - PH ....................................... 24

3.1. Thit b chnh ................................................................................................ 24

3.1.1. B lng t mt ........................................................................................... 24

3.1.2. B aerotank .................................................................................................. 28

3.1.3. B lng t II: .............................................................................................. 37

3.2. Thit b ph ................................................................................................... 40

3.2.1. Song chn rc .............................................................................................. 40

3.2.2. B lng ct ................................................................................................... 43

3.2.3. B iu ha lu lng .................................................................................. 44

3.2.4. B gom bn ................................................................................................. 45

3.2.5. B nn bn ................................................................................................... 47

3.2.6. Thit b kh trng ........................................................................................ 49

CHNG 4: THIT B PH TR ...................................................................... 51

4.1. Tnh ng dn nc ..................................................................................... 51

4.1.1. Cc ng dn nc chnh khi s dng bm.................................................... 51

4.1.2. Cc ng dn nc chnh khng s dng bm ............................................... 52

4.2. Tnh ng dn kh ............................................................................................. 52

4.3. Tnh my nn kh ............................................................................................ 52

CHNG 5: TNH GI THNH THIT B.................................................... 54

TI LIU THAM KHO ..................................................................................... 57

viii

DANH MC BNG BIU

BNG 1.1: PHNG PHP LA CHN THUC NHUM .................................... 5

BNG 1.2: CC CHT GY NHIM V C TNH CA NC THI

NGNH DT NHUM ......................................................................................... 12

BNG 1.3: C TNH NC THI SN XUT CA X NGHIP DT NHUM ......

12

BNG 3.4: H S IU HA K ............................................................................ 24

BNG 3.5: S LIU THIT K B LNG T I .................................................... 28

BNG 3.6: XEM NH B LNG T I CC THNG S HA L SINH HC

GN NH KHNG I ....................................................................................... 28

BNG 3.7: CH S CC CHT B AEROTANK .................................................. 29

BNG 3.8: THNG S THIT K B AEROTANK: ............................................ 36

BNG 3.9: THNG S THIT K B LNG T II: ............................................ 40

BNG 3.10: THNG S THIT K SONG CHN RC ....................................... 42

BNG 3.11: THNG S THIT K B LNG CT .............................................. 43

BNG 3.12: THNG S THIT K B IU HA LU LNG ....................... 45

BNG 3.13: THNG S THIT K B GOM BN .............................................. 47

BNG 3.14: THNG S THIT K B NN BN............................................ 49

BNG 3.15: THNG S THIT K THIT B KH TRNG ........................... 50

ix

DANH MC HNH NH

HNH 3.1. HNH V B LNG T I .................................................................. 27

HNH 3.2. S LP T H THNG PHN PHI KH V CHI TIT A

PHN PHI 35

HNH 3.3. HNH V CHI TIT B AEROTANK .................................................. 36

HNH 3.4. HNH V B LNG T II .................................................................. 39

HNH 3.5. SONG CHN RC .............................................................................. 42

HNH 3.6. B GOM BN ..................................................................................... 46

DANH MC CH VIT TT

x

CPs: Chromophores

ACPs: Auxochromophores

EDTA: Ethylenediaminetetraacetic acid

VSV: Vi sinh vt

TS: Thy sinh

1

LI M U

Nc thi ca cc nh my cng nghip l lnh vc m nhiu ngi c th cn

cha quan tm ng mc. Tuy nhin lng nc thi ny ang tng ngy nh

hng n cuc sng ca chng ta v mi trng sinh thi. V vy x l nc thi

ca nh my cng nghip ang l nhim v t ra ngy cng bc xc trong qu

trnh cng nghip ha hin i ha t nc.

Trn c s , n ny c ni dung nh sau:

Thit k h thng x l nc thi nh my dt nhum.

Nng sut 5000m3/ngy

Cc thng s k thut

COD= 600 mg/l

BOD= 400 mg/l

N= 5

P= 1

SS= 500 mg/l

Nc thi u ra loi B

COD = 100 mg/l

BOD5 = 50 mg/l

N = 1

P = 6

SS = 50 mg/l

2

CHNG 1: GII THIU V NGNH CNG NGHIP DT NHUM

1.1. Tng quan v ngnh nhum [9]

Ngnh cng nghip dt nhum l ngnh c b dy truyn thng thnh ph

H Ch Minh v khu vc ln cn trong nhiu nm qua. Tuy nhin, ngnh dt nhum

vi khu nhum v hon tt vi ca mnh v ang l mt ngun gy nhim mi

trng kh mnh c v lng cng nh cht. c tnh lng nc thi ra t cng

on nhum vi rt ln, t 120 - 300 m3/tn vi.

Nc thi ngnh nhum rt a rng v phc tp. Theo tnh ton cc ha cht

thc hin trong cng on nhum nh: phm nhum, cht hot ng b mt, cht

in ly, cht ngm, cht to mi trng, h men, cht oxy ha... c hng trm loi

cc ha cht c trng, nhiu ha cht ny ha tan di dng ion vi cc kim loi

nng lm tng thm tnh c hi ca nc thi nhum, lm nh hng lu di

n mi trng v sc khe ca con ngi. Hn na, thnh phn v tnh cht nc

thi ngnh nhum hon ton khng n nh, n thay i theo cng ngh v mt

hng v vy vic xc nh thnh phn v tnh cht ca nc thi khng d.

Chnh nguyn nhn , vic tm hiu thnh phn tnh cht nc thi ngnh

nhum cng nh gii php x l i vi cc nc thi nhum khch nhau, xut

cc gii php sn xut sch hn nhm gim thiu nhim ngnh nhum i vi mi

trng.

1.2. Thnh phn tnh cht thuc nhum

1.2.1. Cc loi thuc nhum [6]

Trc khi thuc nhum tng hp u tin xut hin vo nm 1985, ngi ta

s dng thuc nhum thin nhin c sn xut t thcvt. Cc mu thin nhin c

bn mu git v bn mu vi nh sng rt thp, hn na, hiu sut khai thc

thuc nhum t thc vt rt thp nn gi thnh cao. V th, n nay hu ht thuc

3

nhum thin nhin c thay th bng cc loi thuc nhum tng hp, s cn li

ch yu c dng nhum thc phm hoc nhum vi ca cc dn tc t ngi

theo phng php th cng.

Ngy nay, vic nghin cu v ch to thuc nhum tng hp t n nh

cao c v mt khoa hc v cng ngh. Cc loi thuc nhum tng hp c u im l

mu sc p, a dng, bn mu cao v d sn xut hng lot.

Cc loi thuc nhum tng hp ngy nay hu ht c iu ch t du m.

Mi phn t thuc nhum thng c xc nh bi hai thnh phn:

CPs: to nn hiu ng mu.

ACPs: xc nh c tnh ca thuc nhum.

Ta c th phn thuc nhum theo cc cch nh sau:

Theo nguyn liu x si em s dng:

o Thuc nhum dng cho x si gc thc vt nh cotton, liren,

viscose.

o Thuc nhum dng cho x si gc ng vt nh len, t tm.

o Thuc nhum dng cho x si tng hp.

Theo cu to ha hc: bao gm cc nhm nh sau:

Thuc nhum azoic.

o Thuc nhum alanthraquynore.

o Thuc nhum indigoid.

o Thuc nhum arylmethane.

o Thuc nhum nitro.

o Thuc nhum nitroso.

o Thuc nhum polymethyl.

o Thuc nhum lu ha.

o Thuc nhum arylamine.

o Thuc nhum azoicmethyl.

o Thuc nhum hon nguyn a vng.

4

o Thuc nhum phthacyanine.

Theo phm vi s dng: theo cch ny thuc nhum gm 11 phn lp:

o Thuc nhum hon nguyn.

o Thuc nhum lu ha.

o Thuc nhum oxy ha.

o Thuc nhum trc tip.

o Thuc nhum hot tnh.

o Thuc nhum azoic.

o Thuc nhum acid.

o Thuc nhum cationic.

o Thuc nhum phc kim loi.

o Thuc nhum phn tn.

o Thuc nhum pigment.

Vic la chn thuc nhum ph thuc vo nhiu yu t, kh nng cng ngh

ti ni sn xut v nht l bn mu qua git v bn mu nh sng theo yu

cu ca khch hng.

5

Bng 1.1: Phng php la chn thuc nhum [9]

Loi thuc nhum bn git bn nh sng Hiu qu

Trc tip Yu Trung bnh R tin, d s

dng, nng cao

bn sau x l

Axit Trung bnh

tt

Tt Thch hp cho len,

nylon, t tm

Phc kim loi Rt tt Tt Thch hp cho len,

nylon, bn

cao,vi d bng

Cationic Yu Yu

Azoic Tt Tt - rt t Thch hp cho

thuc nhm

Lu ha Tt Trung bnh

Hon nguyn Rt tt Rt tt t tin kh s

dng, bn tt

Phn tn Trung bnh

tt

Trung bnh tt phn tn cao

Hot tnh Yu Yu Thch hp vi

cellulose

1.3. Tnh c ca phm nhum [3]

1.3.1. Tnh c ca phm nhum

6

Cc vn v mi trng ch yu lin quan n cc cht thi vo nc nhng

ngoi ra, pht thi vo khng kh, ting n v vic giao nhn cc cht thi c hi

cng rt quan trng, Vic s dng cc ho cht c nh hng ng k ti mi

trng ca ngnh cng nghip.

Pht thi vo nc

Hu ht cc khu trong quy trnh cng ngh ca cng nghip dt nhum u

pht sinh ra nc thi. c trng c bn ln nht ca nc thi cng nghip dt

nhum l s dao ng rt ln v c lu lng, ti lng cht nhim. N thay i

theo ma, theo mt hng sn xut v cht lng sn phm. Cc cht thi vo

nc bao gm nc thi t quy trnh sn xut, nc ra v nc lm lnh b

nhim nhiu hn hoc t hn. Nc ra chim 60-70% tng lng nc tiu th.

Nc thi cha mt hn hp cc ho cht s dng. Cc ho cht nht nh

v d nh cht ty, bt git u hu nh ton b vo h thng nc thi, trong

khi mt s khc nh thuc nhum li gi phn ln trn sn phm.

Phn ln cc cht hu c lm tng lng BOD5 trong nc thi u pht sinh

t cc cht dng h vi. Nc thi cn c th cha hm lng du tng i cao, c

l c ngun gc t cht bo t nhin, sp v cc loi du ngun gc t xng dng

khi xe si. Vn kim loi ln trong nc thi c gim bt t khi thi dng

cc cht gi mu nhum c kim loi nng. Tuy nhin, kim loi, c bit l kim loi

ng v km vn cn c s dng trong mt s kiu nhum. Ngoi ra, nc thi

cn c cha mt lng cht rn l lng, ch yu l si vi, vi cc ho cht bm

cht vo.

Rt nhiu loi thuc nhum ang dng l cht chm hy v c th cha cc

kim loi, c bit l ng v km. Ngoi ra cn c th c mt lng nh Cadimi,

Chrom v Ch. Phn ln cc thuc nhum c loi b qua khu x l sinh hc.

Mt s loi thuc nhum qua nghin cu cho thy cc k c hi. Tuy nhin,

khng th nh gi tng qut c tnh ca cc thuc nhum v cc cht ny hon

ton khc nhau. Phn ln cc thuc nhum c s dng hin nay l thuc nhum

7

hot ho v cc cht mu. Mc n nh ca thuc nhum hot ho l 50-85% so

vi 90% i vi cc cht gi mu thuc nhum.

Cc cht cha chlorinat aromat c coi nh mt trong s cc cht c hi

nht i vi mi trng. Hin nay, cc cht mang thng khng c s dng na.

Cc nghin cu cng cho thy cc cht x l sau khi nhum c th l nhng cht

chm hy.

Cc hp cht phospho hu c nh cht chng chy v phc cht khng c

tch loi hon ton cc nh my x l nc thi. Cc cht c dng lm cht

chng chy bao gm hp cht bromin hu c, c bit l decabromin defenyl oxid

v antimon trioxid. Cc cht chng chy brominat u tch lu sinh hc. Ngoi ra,

cc phc cht EDTA cng c th nh hng n h thng x l nc thi a

phng.

Cc cht in hot cation c coi l c th phn hy nhng u tng i

c. Chng hn, sn phm phn hy ca hp cht amoni rt c. Tuy nhin, cc

cht ny d b hp ph vo cc cht rn v c th tch chng ra cc nh my x

l.

Pht thi vo khng kh

Khc vi nhiu loi hnh cng nghip khc, cng nghip dt nhum thng

i hi lng nhin liu rt ln phc v cho vic cung cp nhit lng cho qu trnh

sn xut ca mnh thng qua thit b l hi. Nhin liu thng dng l than, du FO

hoc DO. Cc nhin liu ny khi chy chng to ra trong mi trng khng kh cc

cht nhim khng kh rt ln nh bi, bi l lng, kh SO2, COx, NOx. Kh thi

ca qu trnh t nhin liu thng c nhit tng i cao, nn chng c kh

nng khuch tn ra mi trng tng i rng ln gy nh hng n i sng ca

nhn dn xung quanh khu vc sn xut.

Mi sinh ra trong qu trnh cng ngh thng kh nh lng c do cha c

tiu chun c th no i vi mi. Tuy nhin, do s dng nhiu ha cht khc nhau

trong sn xut, mi thng xut hin ti khu vc s dng NaClO, NaClO2 thng

8

c cm gic mi hc, cc khu vc s dng NaOH to cm gic kh. Nc thi ca

cng on h si cha nhiu h tinh b sau khi thi rt d b bin cht gy mi kh

chu nhn chung i vi cng ngh dt nhum do phi tip xc nhiu vi cc loi

ha cht, s nguy him nu nh cng nhn khng c trang b cc thit b bo h

lao ng hon thin (khu trang, gng tay, qun o bo h).

t

nhim mi trng t ch yu thng qua nc thi v cc cht thi rn trong

h thng x l nc thi. t tip nhn nc thi b nhim bi hm lng cht

hu c bn phn hy cao, lng cc ion c tnh nng lm phn ly cc keo t ln

nn l bin i cu trc t, hn ch s pht trin ca cc vi sinh vt c li. Thnh

phn kh dng kh chim u th lm mt cn bng th kh trong t. Ngoi ra, cng

nghip dt nhum thng c mt bng sn xut tng i cao nn din tch t s

dng cho cc nh my thng ln.

Ting n

Cng nghip dt nhum c mc n bin thin rt khc nhau cc v tr khc

nhau ca quy trnh cng ngh. ng ch nht l ting n gy ra bi qu trnh dt,

hot ng ca cc my lc ht bi trong qu trnh dt, lm sch nguyn liu, chi v

ko nh ng si. Mc n ti cc khu vc ny thng cao n 80 95 dBA, ng

ngi hn na ting n li lin tc cao. Do , cng nhn l vic lu di trong ngnh

dt nhum thng mc chng nng tai. Mc n cc khu vc khc thng nh v

khng thng xuyn vt tiu chun (ngt qung).

Cht thi

Ngnh cng nghip dt to ra nhiu cht thi c hi di dng du v dung

mi thi cng nh cc ho cht v thuc nhum. Cc cht thi khc gm c vi si,

cn t h thng x l v iu ho dng chy, t khu ng gi v cc qu trnh

tng t.

Cht thi rn c sinh ra ch yu t cc ngun sau y:

9

Cht thi do qu trnh t nhin liu, cht thi rn sinh ra c tnh bng

khong 15 25% lng nhin liu tiu th.

Cht thi rn l cc bi lng ng hoc do v sinh thit b lc bi.

Cc loi bao b, nhn mc sn phm sau khi s dng hoc l cc ph phm.

Cc loi chai l, bao b, thng ng ha cht v vt liu phc v cng ngh dt

nhum. ng lu rng, cht thi thuc loi ny l cc cht thi nguy hi.

Cht thi rn do giao dch, sinh hot t nh n,vn phng.

Pht thi do c s c

Nhng trc trc hoc tm ngng hot ng trong cc quy trnh v cc thit b

x l hay chuyn giao ho cht khng hp l c th dn n pht sinh cht thi vi

s lng ln, hm lng ln vo nc v khng kh. Chng hn nu b phn iu

chnh pH b hng, s c th c ri lon h thng x l nc thi hoc ni tip

nhn nc thi.

Du (du nng) c s dng lm trung gian truyn nhit trong nhng giai

on quyt nh ca quy trnh, nh giai on sy kh chng hn, Do , c th c

s c do du i ra gy nn. Ngoi ra cng cn phi lu n nguy c chy.

1.3.2. nh hng n con ngi v ng vt

Trong phn ny xin cp n mt s kin thc c bn v mt s loi phm

nhum c kh nng gy c cho con ngi v ng vt. Ni chung, cc loi phm

nhum u c cha cc kim loi nng v cc cht hu c c hi, tuy nhin c mt

s loi gy phn ng c trc tip khi tip xc. Cc loi phm nhum ny thng

c gi l phm nhum AZO.

Danh sch trn khng th bao gm ht c trong tng s hn 80.000 loi

phm nhum ha hc khc nhau trn th trng.

Phm nhum AZO c gii thng mi a chung v chng d mua, d bo

qun c bit l gi thnh r, n mu cao, qu trnh nhum ngn v d dng.

10

nh hng ca chng ln con ngi trong qu trnh nhum cng nh tip xc

vi dng thi ca chng

o Hi bc ln t dung dch nhum c th gy ng c cho ngi, lm au u, bun nn.

o Khi thuc nhum tip xc trc tip trn da, chng c th gy rt. o Nu thm nhp vo c th, gy tn thng cc c quan ni tng v gy

ung th.

o i vi tr em, liu lng gy c nh hn v nh hng mnh hn.

Khi b nhim c thuc nhum, tr hay c cm gic bun ng, au u,

chng mt bun nn, thiu tp trung.Vi liu lng ln, tr c th mt cm

gic ngon ming, yu t chi thm ch gy t vong.

o i vi thai nhi c th chm pht trin, hng xng, m hoc thm ch gy t vong.

1.4. Cng ngh sn xut v ngun pht sinh nc thi [3]

Nc thi pht sinh trong cng ngh dt nhum l t cc cng on h si, gi

h, nu, ty, nhum v hon tt, trong lng nc thi ch yu do qu trnh git

sau mi cng on. Nhu cu s dng nc trong nh my dt nhum rt ln v thay

i theo cc mt hng khc nhau. Nhu cu s dng nc cho 1 mt vi nm trong

phm vi t 12 n 65 lt v thi ra t 10 n 40 lt.

Theo H.Ruffer, lng nc thi tnh cho mt n v sn phm ca mt s mt

hng nh sau:

Hng len nhum, dt thoi (bao gm x l s b v nhum) l 100 n 250

m3/tn vi.

Hng vi bng, nhum, dt thoi l 80 n 240 m3/tn vi, bao gm:

H si; 0,02 m3/tn vi.

Nu, gi h, ty: 30 n 120 m3/tn vi.

Nhum: 50 n 120 m3/tn vi.

11

Hng vi bng nhum, dt kim l 70 n 180 m3/tn vi.

Hng vi bng in hoa, dt thoi l 65 n 280 m3/tn vi.

H si: 0,02 m3/tn vi.

Gi h, nu, ty: 30 n 120 m3/tn vi.

In, sy: 5 n 20 m3/tn vi.

Git: 30 n 140 m3/tn vi.

Chn len mu t si polyacrylonitrit l 40 n 140 m3/tn vi, bao gm:

Nhum si: 30 n 80 m3/tn vi.

Git sau dt: 10 n 70m3/tn vi.

1.4.1. Cc cht gy nhim chnh trong nc thi ca cng nghip dt nhum

bao gm [3]

Cc tp cht tch ra t vi si nh du m, cc hp cht cha nit, pectin, cc

cht bi bn dnh vo si (trung bnh chim 6% khi lng x si).

Cc ha cht s dng trong quy trnh cng ngh nh h tinh bt, H2SO4,

CH3COOH, NaOH, NaOCl,H2O2 , Na2CO3 , Na2SO3 cc loi thuc nhum, cc

cht tr, cht ngm, cht cm mu, cht ty git. Lng ha cht s dng i vi

tng loi vi, tng loi mu thng khc nhau v ch yu i vo nc thi ca tng

cng on tng ng.

c trng quan trng nht ca nc thi t cc c s dt nhum l s dao ng rt

ln v lu lng v ti lng cc cht nhim, n thay i theo ma theo, mt

hng sn xut v cht lng ca sn phm. Nhn chung nc thi t cc c s dt

nhum c kim kh cao, mu v hm lng cc cht hu c, tng cht rn

cao. c tnh nc thi v cc cht gy nhim trong nc thi ngnh dt nhum

c th hin theo bng di:

12

Bng 1.2: Cc cht gy nhim v c tnh ca nc thi ngnh dt nhum

Cng on Cht nhim trong nc thi

c tnh ca nc thi

H si, gi h

Tinh bt, glucose, carboxy metyl xelulo, nha, cht bo v sp

BOD cao (30 n 50% tng sn lng BOD)

Nu ty NaOH, cht sp v du m, soda, silicat natri v x si vn

kim cao, mu ti, BOD cao (30% tng BOD)

Ty trng Hypoclorit, hp cht cha clo, NaOH, AOX, axit

kim cao, chim 5% BOD.

Lm bng NaOH, tp cht kim cao, BOD thp (di 1% tng BOD)

Nhum Cc loi thuc nhum, axit axetic v cc mui kim loi

mu cao, BOD cao v du m

Hon thin Vt tinh bt, m ng vt, mui

Vt tinh bt, m ng vt, mui

Bng 1.3: c tnh nc thi sn xut ca x nghip dt nhum [3]

Cc thng s n v Gi tr nh nht

Gi tr trung bnh

Gi tr cc i

pH - 8,5 - 10,3

Nhit oC 25 27 38

COD mg O2/l 420 650 1400

BOD5 mg O2/l 80 180 500

TOC mg/l 100 202 350

Tng photpho mg/l 26 50 80

SO4 mg/l 750 810 1050

S2 mg/l < 0,1 < 0,1 0,8 Cl mg/l 400 800 1650

AOX mg/l 0,5 0,8 1,2

Crom mg/l < 0,01 0,015 0,034 Nikel mg/l < 0,1 < 0,1 0,4

13

Hm lng cc cht thi gy nhim trong nc thi ca tng loi c s ca tng

loi hnh cng ngh v trong loi sn phm thng khc nhau v thay i t c s

ny sang c s khc, cng nh thay i ln trong ngy ti mt c s sn xut.Cc

gi tr ny phi c o v ly mu phn tch cho tng c s cng nh cc thi

im khc nhau i vi mt c s. Th d v c tnh nc thi ca mt x nghip

dt nhum mt hng bng dt kim vi lng nc thi 70 180 m3/tn sn phm

nh bng trn.

nh hng ca cc cht gy nhim trong nc thi ngnh dt nhum ti

ngun tip nhn c th tm tt nh sau:

kim cao lm tng pH ca nc. nu pH > 9 s gy c hi vi

cc loi thy sinh, gy n mn cc cng trnh thot nc v h thng x

l nc thi.

Mui trung tnh lm tng hm lng tng cht rn TS. Lng thi ln

gy ra tc hi i vi cc loi thy sinh do lm tng p sut thm thu,

nh hng ti qu trnh trao i cht ca t bo.

H tinh bt bin tnh lm tng BOD5, COD ca ngun nc, gy tc hi

i vi i sng thy sinh do lm gim lng oxy ha tan trong ngun

nc.

mu cao do lng thuc nhum d i vo nc thi gy mu cho

dng tip nhn, nh hng ti qu trnh quang hp ca cc loi thy

sinh, nh hng xu ti cnh quan. Cc cht c nh sunfit, kim loi

nng, hp cht halogen hu c (AOX) c kh nng tch t trong c th

sinh vt vi hm lng tng dn theo chui thc n trong h sinh thi

ngun nc, gy ra mt s bnh mn tnh hay ung th i vi ngi v

ng vt.

Hm lng nhim cc cht hu c cao s lm gim oxy ha tan trong

nc, nh hng ti s sng ca cc loi thy sinh.

1.5. X l nc thi cng nghip dt nhum

14

1.5.1. Cc phng php ngn nga, gim thiu

Gim nhu cu s dng nc bng cch thng xuyn kim tra h thng

cp nc tranh r r nc. S dng modun ty, nhum, git hp l. T

ng v ti u ha qu trnh git nh git ngc chiu. Tun hon v

x dng li cc dng nc git t i nhim v nc lm ngui.

Hn ch s dng ha cht, thuc nhum c hi kh phn hy sinh hc.

Nn s dng cc ha cht, thuc nhum t nh hng ti mi trng,

thnh phn kim loi nng nm trong gii hn cho php.

S dng nhiu ln dch nhum va tit kim ha cht v trnh i nhim

mi trng.

Vn thu hi thuc nhum t dch nhum hoc t nc thng phc tp i

hi cng ngh x l cao. Cho ti nay ch c mt s nc thnh cng trong vic thu

hi thuc nhum indigo t qu trnh nhum si bng bng phng php siu lc.

Gim cc cht i nhim nc thi trong qua trnh ty. gim lng

cht ty dng Clo m vn m bo trng ca bng, c th kt hp

ty hai cp. Cp 1 ty bng NaOCl c b sung H2O2 v un nng

tin hnh ty cp 2.

Gim i nhim kim trong nc thi bng cch lm bng vi nhit

cao ( 60oC 70oC ) gim 10% nc vi khi thc hin 25oC 30oC.

Thu hi v s dng li dung dch h t cng on h si v gi h. Tuy

nhin thu hi v s dng li cc loi h trong cng nghip thng phc

tp v nhiu khi khng kinh t, ch s dng nhng nc c nn cng

nghip pht trin.

1.5.2. Cc phng php x l

t hiu qu x l, cn phn lung dng thi theo cc loi:

Dng i nhim nng nh dch nhum thi, dch h, nc git u ca

mi cng on.

Dng i nhim va nh cc cng on trung gian.

15

Dng i nhim nh nh nc lm ngui, nc git cui.

i vi cc dng nc thi phn lung nh vy c th x dng cc

bin php:

- Tch tp cht c hc bng, tuyn ni.

- Tch, x l cht c bng phng php ha l, ha hc.

- X l sinh hc: x l hiu kh aerotank, thp hp th sinh hc,...

16

CHNG 2: THIT K QUY TRNH X L NC THI DT NHUM

2.1. C s l thuyt ca qu trnh s l

c tnh nc thi cng nhip dt nhum phc tp, cha cc cht ha hc kh

phn hy (thuc nhum), hm lng BOD5 cao (nc thi cha h tinh bt bin

tnh), do vy khi tinh ton thit k quy trnh x l phi kt hp nhiu phng php

(c hc, ha hc, sinh hoc) mi t kt qu nh mong mun.

2.1.1. X l nc thi bng phng php c hc

Cc loi thit b x l gm:

- Lng: dng khi khi lng ht cn ln hn khi lng ring ca nc

thi.

- Tuyn ni: dng khi khi lng ht cn nh hn khi lng ring ca

nc thi.

- Lc: i vi ht cn c kch thc nh.

- p: dng nn bn sau khi lng.

Cc thit b c hc b tr xen k gia cc qu trnh x l khc, nm t u

n cui quy trnh x l nc thi, c tc dng h tr, nng cao hiu sut

ca cc qu trnh khc. Sau x l c hc tnh cht ha l, sinh hc ca

nc thi khng thay i.

2.1.2. X l bng phng php ha l

Cc cht ng t thng dng l mui nhm, st hoc hn hp ca

chng. Vic chn la cht ng t ph thuc vo tnh cht ha l, chi

ph, nng cc cht trong nc, pH v thnh phn mui trong nc.

Trong thc t ngi ta thng hay x dng cc cht ng t sau:

Al2(SO4)3.H2O, NaAlO2, Al2(OH)5Cl, KaAl(SO4)2.12H2O,

NH4Al(SO4)2.12H2O. Trong x dng rng ri nht l Al2(SO4)3 v

17

ha tan tt trong nc, chi ph thp v c hiu qu cao trong khong pH

5-7.5. Trong qu trnh ng t xy ra phn ng:

Al2(SO4)3 + 3Ca(HCO3)2 = Al(OH)3 + CaSO4 + 6CO2

Phn Al2(SO4)3.18H2O c iu ch t boxit v axit sunfuric. Ty

thuc phng php sn xut v nguyn liu thu c cc loi phn

nhm khc nhau: phn nhm khng tinh khit v phn nhm k thut.

NaAlO2 c sn xut bng cch ha tan bt Al(OH)2 hay Al2O3 vo

dung dch NaOH.

u im ca phng php ha l so vi phng php sinh hc:

C kh nng loi cc cht c hu c khng b oxi ha sinh hc.

Hiu qu x l cao hn v n nh hn.

Kch thc h thng nh gn.

nhy vi s thay i ti trng thp hn.

C th t ng ha hon ton.

ng hc ca qu trnh ha l c nghin cu su hn.

Phng php ha l khng cn theo di cc hot ng ca vi sinh.

C th thu hi cc cht khch.

2.1.3. X l bng phng php ha hc

Cc phng php ha hc u lin quan n vic tiu hao tc cht, v vy chi

ph ln. Ngoi ra khi x l bng phng php ha hc thng sinh ra nhim th

cp, do ch s dng khi cht nhim khng th loi c bng cc phng php

khc.

C s ca phng php ny l cc phn ng ha hc din ra gia cc cht

nhim v cht thm vo. Nhng phn ng ha hc din ra c th phn ng oxy ha

kh, phn ng trung ha tp cht kt ta hoc cc phn ng thy phn cc cht c

hi. Cc phng php dng nhiu nht l oxy ha v trung ha.

2.1.3.1. Phng php oxy ha

Phn ng oxy ha thng c ng dng x l nc thi cng nghip nhim

18

bn bi cc cht v c, hu c c hi. Tuy nhin, thc t ch c ng dng khng

th loi bng phng php khc. Cc cht oxy ha thng dng l Clo, NaOCl,

CaClO2, pecmanganat kali, H2O2, oxi khng kh...

2.1.3.2. Trung ha

Nc thi cng nghip c th c kim hoc axit cao. Chnh v th trc

kh s dng trong qu trnh cng ngh cn c trung ha. Qu trnh trung ha

c thc hin trong cc b trung ha lm vic lin tc hoc gin on theo chu k.

V cu to, b ny c th kt hp vi cc b lng phi da trn c s so snh cc

ch tiu kinh t k thut chn phng php lng.

Cc phng php trung ha thng c dng:

Trung ha bng cch trn hai dng nc thi cha acid v kim. y l bin

php n gin, d thc hin v t tn km chi ph.

Trung ha nc thi bng cch thm ha cht.

Trung ha nc thi cha acid bng cch cho qua lp vt liu trung

ha, thng vt liu lc l vi.

Trung ha bng kh acid.

2.1.4. X l bng phng php sinh hc

X l sinh hc nc thi thc cht l li dng s sng v hot ng sng ca

cc vi sinh vt thc hin cc dng phn hy khc nhau. S phn hy cht hu c

thng km theo s thot kh di tc dng ca cc enzym do vi khun tit ra.

Nhim v ca cng trnh k thut x l nc thi bng phng php sinh hc

l to iu kin sng v hot ng tt nht cho cc vi sinh vt phn hy cc cht

hu c c nhanh chng.

Cc quy trnh xy ra trong thit b

Qu trnh bin i bao gm cc phn ng ha hc bn trong t bo, c 2 phn

ng c bn trong qu trnh bin i l phn ng d ha v phn ng ng ha.

19

Phn ng d ha b gy cc mch hu c, phn chia cc phn t hu c

phc tp thnh cc phn t n gin hn v km theo qu trnh l s

gii phng nng lng.

Phn ng ng ha lm hnh thnh cc phn t phc tp hn v i hi

cp nng lng. Nng lng cp cho phn ng d ha thng ly t

nng lng c gii phng ra ca cc phn ng d ha.

Vai tr ca enzym

Enzym l cht xc tc hu c do cc t bo sng sinh ra - l cc protein hoc

cc protein kt hp vi cc phn t v c hoc hu c c trng lng thp. Nh

mt cht xc tc, enzym c kh nng lm tng tc phn ng ha hc ln gp

nhiu ln nhng bn cht khng b thay i.

Vai tr ca cht dinh dng

Vi sinh vt tiu th cc cht hu c sng, hot ng v i hi mt lng

cht dinh dng Nit v photpho pht trin. Ngoi ra cn mt lng nh cc

nguyn t khong nh canxi, magie, st, ng, km, mangan. Trong N, P v K l

cc nguyn t ch yu, cn c m bo mt lng cn thit trong x l sinh ha.

Khi thiu Nit lu di, ngoi vic cn tr qu trnh sinh ha cc cht bn hu

c, cn to ra bn hot tnh kh lng.

Khi thiu photpho dn n s pht trin vi khun dng si, l nguyn chnh

lm cho bn hot tnh b phng ln, kh lng v b cun theo dng chy ra khi h

thng x l, lm gim sinh trng ca bn hot tnh v gim cng ca qu trnh

oxy ha.

Hm lng cc cht dinh dng ph thuc vo thnh phn nc thi. c

th x l bng phng php sinh hc thiu kh t l ny thng trong khong BOD

:N : P = 100 : 5 : 1. Ngoi ra cn mt lng nh cc nguyn t khong nh canxi,

magie, st, ng, km, mangan. Cc cht ny thng c trong nc thi sinh

hot. Khi x l nc thi cng nghip, nhiu trng hp phi b sung N, P ( c th

trong iu kin n ny phi b sung N, P ) v kh trc cc kim loi nng gy

20

c hi xung n nng cho php.

2.2. Thit k quy trnh x l nc thi

Nc thi c phn lung tng hiu qu x l, mi lung ta u lp

song chn rc v c b lng ct. Nc thi cha thuc nhum( b nhim nng)

c s l ha hc trc khi x l sinh hc.

Cc thit b trong quy trnh x l: ( Xem bng sau)

Thuyt minh quy trnh x l:

Ton b nc thi c dn v ngn tip nhn sau khi qua song chn rc bng

mng thot nc t chy. Nc thi tip tc t chy sang 2 b iu ha ni tip

nhau, trong b b tr 2 my thi kh nhm xo trn u nc thi v ngn nga hin

ng cn trong b.

T b iu ha nc thi c bm ln thp gii nhit vi mc ch gim

nhit nc thi t 600C xung 400C sau nc thi chy v trung gian. Ti y

b tr my thi kh lun phin nhm mc ch xo trn u nc thi v hiu chnh

pH thch hp cho qu trnh x l sinh hc pha sau.

T b trung gian, nc thi chy sang cm b x l sinh hc vi 2 b bn hot

tnh hiu kh l lng v 1 b bn hot tnh dnh bm. Nc thi sau qu trnh bn

hot tnh hiu kh tip tc t chy qua 3 b bn hot tnh vi vt liu dnh bm to

iu kin thun li cho VSV pht trin tip tc phn hy cc cht hu c trong

nc thi.

Sau khi qu trnh x l cum b sinh hc nc thi t chy sng b lng I vi

mc ch lng cc bng bn sinh hc. Bn t b lng c a sang b nn bn.

Nc thi tip tc c a sang b keo t v b to bng tng kch thc ca

cc bng cn. Ha cht kh trng cng c chm vo cc b to bng nhm mc

ch loi b VSV gy bnh trong nc thi.

Sau qu trnh to bng, hn hp nc v bng cn t chy v b lng II. Ti

b lng bng cn c tch khi nc thi di tc dng ca trng lc. Nc trong

21

c thu qua mng trng tip tc chy qua mng tip xc v cui cng chy v h

cha nc.

Bn t b lng II c bm vo b nn bn. Phn ln lng bn hot tnh t

b nn bn c bm tun hon v cm x l sinh hc, phn bn d c bm

sang my p bn tch nc.

2.2.1. Song chn rc

Song chn rc gm cc thanh chn lm bng thp khng r, sp xp cnh nhau

v hn c nh trn khung thp, c t trn mng dn nc, khong cch gia

cc thanh thp gi l khe h.

Thanh chn rc c th dng loi tit din trn d = 8410, ch nht s b =

1010 v 860, thanh tit din trn t c s dng v rc d dnh vo thanh chn

gy kh khn cho vic vt rc. c s dng nhiu nht l thanh tit din hnh ch

nht, tuy nhin loi ny c tn tht thy lc ln.

2.2.2. B lng ct

Trong cn c ct s lm cho ng dn bn khng hot ng c, my bm

chng hng. i vi trm x l nc thi ln hn 100m3/ngy th xy dng b lng

ct l cn thit. Theo nguyn tc chuyn ng ca nc trong b, ngi ta phn bit

b lng ct ngang, b lng ct ngang nc chuyn ng vng trn, b lng ct ng

nc chuyn ng t di ln trn, b lng ct chy theo phng tip tuyn, b lng

sc gi... Trong thc t b lng ct ngang c s dng rng ri nht.

2.2.3. B iu ha lu lng

Do tnh cht nc thi thay i theo tng gi sn xut v n ph thuc vo

tng loi nc thi theo tng cng on, v vy cn xy dng b iu ha cc

cng trnh x l lm vic vi lu lng u trong ngy s kinh t hn. B iu ha

c nhim v iu ha nc thi v lu lng v nng . B iu ha cn lm gim

kch thc v to ch lm vic n nh, cho cc cng trnh sau ny, nht l chnh

hin tng qu ti ca h thng x l.

LONGTypewriter

LONGTypewriter

LONGTypewriter

LONGPencil

22

2.2.4. B lng t I

C nhim v tch loi cc cht l lng c trng lng ring ln trng lng

ring ca nc. ng thi b lng t I cn c th loi b mt phn cc cht hu c

ha tan trong nc nh COD, BOD5.

Chn b lng ng v nng sut x l nh, hn na quy trnh hot ng lin

tc do b lng ng thun tin cho vic tho cn.

2.2.5. B phn ng Aerotank

Nc thi c t s BOD5:COD = 400600 = 0,66 thch hp x l bng phng

php hiu kh.

Cc cng trnh nhn to x l hiu kh gm: b aerotank, thp lc sinh hc, b

hiu kh, mng oxy ha...

Qu trnh chuyn ha vt cht trong b da hot ng sng ca cc vi sinh vt

hiu kh. Cc vi sinh vt trong b aerotank tn ti dng huyn ph. Cc huyn ph

vi sinh vt c xu hng lng ng xung y, do vic khy trn dung dch trong

b l iu cn thit.

Ngi ta c th cung cp kh trong b aerotank bng nhiu cch: thi kh, nn

kh, lm thong c hc, thi nn kh vi h thng c hc.

2.2.6. B lng t II

C nhim v chn gi cc bng bn hot tnh qua x l b aerotank hay

mng vi sinh biophin (b lc sinh hc) v cc thnh phn cht khng tan cha

c gi li b lng t I, l mt cng trnh n v trong dy chuyn x l nc

thi bng phng php sinh hc.

V cu to b lng t II tng t b lng t I, c th l cc b lng ng,

ngang, radian ( hng tm v ly tm)...

y chn b lng hng tm do lu lng vo b lng t II cao hn b

lng t I ( c dong lu lng tun hon).

2.2.7. B gom bn

23

B gom bn gm 2 ngn: ngn cha bn tun hon v ngn cha bn d.

Nguyn l hot ng nh sau:

Bn hot tnh sau khi lng b lng t II t n nng nht nh c a

vo ngn cha bn d. Ngn ny c xy dng c th tch ng bng lng bn

phi x hng ngy. Do ngi ta phi x bn mi ngy mt ln. Bn hot tnh sau

khi cha y ngn cha bn d, chy trn qua ngn cha bn tun hon v c

bm tr li b aerotank tip tc tham gia qu trnh x l nc thi.

2.2.8. B c c cn

Gim khi lng bn cn bng cch gn mt phn hay phn ln lng nc

c trong hn hp gim kch thc thit b x l, gim trng lng vn chuyn

n ni tip nhn, hn ch nc bn ngm vo nc ngm bi thi.

2.2.9. Thit b kh trng

Sau khi x l sinh hc, phn ln cc vi khun trong nc thi b tiu dit,

nhng tiu dit ton b vi sinh vt phi kh trng bng phng php clo ha,

ozon ha, in phn, chiu tia nng lng.

2.2.10. Sn phi bn

Cn t b thu bn c dn n sn phi bn lm ro nc. Sn phi bn

l vng t rng c quy hoch, chia thnh mi v xung quanh mi u c b.

Cc cn dn n sn phi bn u c m rt ln 96 97%, nhim v ca

sn phi bn h m cc loi cn trn xung 75 80%.

24

CHNG 3: TNH TON THIT B CHNH - PH

3.1. Thit b chnh

Cng sut nc thi: Theo bi: Q = 5000 m ngym = 208,33m h = 0,057 m s Q : lu lng nc thi trung bnh ngy m Lu lng nc thi gi cao im: Q = K Q = 208,33 1,57 = 0,091 m s 327 m h (3.1) Q: Lu lng nc thi gi ln nht Q: Lu lng nc thi gi trung bnh K l h s iu ha cxcnh theo bng sau: [1,9] Bng 3.4: H s iu ha K Lu lng nc

thi trung bnh

5 15 30 50 100 200 300 500 800

H s khng

iu ha K

3 3,5 1,8 1,6 1,4 1,35 1,25 1,2 1,15

(Khi lu lng nm gia cc ch s trong bng th xc nh h s iu ha K theo ni suy) K = 1,57 3.1.1. B lng t mt [1]

- Chc nng:

B nng t mt c nhim v tch loi cc cht l lng c trng lng

ring ln hn trng lng ring ca nc. ng thi b lng t 1 cn c

25

th loi b cc cht hu c ha tan trong nc nh COD, BOD5.[4,44]

Chn b lng ng v nng sut x l nh, hn na quy trnh hot ng lin

tc, do b lng ng thun tin cho vic tho cn.

- Tnh ton: t cng thc 3.2 n 3.13 [1,45]

Chiu di ng trung tm (chiu cao cng tc ca b). [1] h = V t(3.2) V: tc nc dng, chn V = 0,5mm/s.

t: thi gian lu nc, chn t = 1,5 (h)

h = 0,5 1,5 3600 = 2700mm = 2,7m Th tch tng cng ca b [1] W = Q t = 327 1,5 = 490,5m(3.3) ChnW = 491m

Hiu qu kh BOD5 l: [1,48] R = ta + b. t = 1.50,018 + 0,02.1,5 = 3,25%(3.4) Hiu qu x l SS :

R = ta + b. t = 1.50,0075 + 0,014.1,5 = 52,63% Trong :

R : Hiu qu kh BOD5 hoc SS

t : Thi gian lu nc

a, b : Hng s thc nghim, chn a = 0,018, b = 0,0075, ti t = 20oC.

Tit din phn cng tc ca b [1]

F = Wh = 4912,72,7 = 181,85m(3.5)

LONGTypewriter

LONGTypewriter

LONGPencil

LONGPencil

26

Tit din ng trung tm

f Qv = 0,0910,03 = 3m(3.6) vo: Vn tc nc chy trong ng trung tm, chn vo = 0,03m/s

Tit din tng cng ca b lng F = F + f = 181,85 + 3 = 184,85m (3.7) ng knh b lng

= 4.. 3,14 = 4.184,852.3,14 = 10,85

n: s b lng, n c chn hp l ng knh b lng khng ln hn 9.

Chn n = 2.

Thtchcamtb: V = 490,52 = 245,25m Chiu cao tng cng ca b

cn t chy ti h thu cn th gc to bi ng y b v mt phng nm

ngang khng nh hn 45O. Chn gc nghing bng 50O, chiu cao phn y nn:

h = D tg502 = 10,85 tg502 = 6,46m(3.8) Tng chiu su ca b lng ng H = h1 + h2 + h3 + h4 + h5 + h6 = 2,7 + 0,3 + 0,3 + 6,46 + 1,2 = 10,96m (3.9)

h1: chiu cao phn cng tc.

h2: khong cch t ming loe ng trung tm n phn phn x, chn h2= 0,3m.

h3: chiu cao lp bo v trn b lng ly bng 0,3m.

h4: chiu cao phn y nn, h4 = 6,46m.

27

h5: chiu di ng loe, h5 = 1,2m.

Tnh ng trung tm

ng knh ng trung tm :

d = 4. fn. 3,14 = 4.32.3,14 = 1,38m(3.10) ng knh ming loe: D1 = 1,35d = 1,351,38 = 1,863m (3.11) Chiu di ng loe: h = 1,35d = 1,351,38 = 1,863m ly trn 1,87m (3.12) ng knh tm chn: Dc = 1,3D1 = 1,31,863 = 2,42m (3.13)

Hnh 3.1. Hnh v b lng t I v chi tit ng loe

LONGPencil

28

Bng 3.5: Thng s thit k b lng t I

STT Tn thng s n v S liu thit k

1 S b 2

2 Th tch mi b m3 245.25

3 Tit din tng cng m2 184.85

4 ng knh b m 10.85

5 ng knh ng trung tm m 1.38

6 Chiu di ng trung tm m 2.7

7 ng knh tm chn m 2.42

8

Chiu su tng cng m 10.96

Bng 3.6: Xem nh b lng t I cc thng s ha l sinh hc gn nh khng

i

Ch s i nhim n v u vo Hiu sut u ra

SS mg/l 500 0,6 50

3.1.2. B aerotank

29

Bng 3.7: Ch s cc cht b aerotank

Ch s nhim n v u vo u ra

COD mg/l 600 100

BOD5 mg/l 400 50

SS mg/l 500 50

- Chc nng:

Aerotank l tn gi b cha nc bng b tng ct thp c thng kh. Qu

trnh x l trong cc aerotank din ra theo dng nc thi c xc kh v trn vi

bn hot tnh. Nc thi c cho vao b lng, tng cng s lng ca cc ht l

lng c th cho vo y mt phn bn hot tnh.

- Tnh ton: t cng thc 3.14 n 3.34 [1,64]

Tnh nng BOD5 ha tan trong nc u ra:

Lng cn hu c trong nc ra khi b: = SSu ra %cnhu c = 50 0,65 = 32,5mg/l (3.14) Lng cn hu c tnh theo BOD20 = 1,42 32,5 0,7 = 32,3mg/l (3.15) (Do 1mg cht hu c = 1,42mg BOD20, tro ca c l 0,3) BOD5 u ra nc thi dng rn = 32,3 0,68 = 21,97mg/l (1mg BOD5 = 0,68mg BOD20) BOD5 u ra nc thi dng ha tan: S = 50 21,97 = 28,07mg/l

Tnh hiu qu x l:[1]

Hiu qu x l theo BOD5 ha tan: E = S SS = 400 28,03400 100% = 93%(3.16)

30

So: lng BOD5 ban u ca nc thi

Tnh th tch b aerotank:

Th tch ca b tnh theo tui ca cn:[1,2]

V = Q. Y. . (S S)X. (1 + K. ) = 5000.0,46.10. (400 28,03)2800. (1 + 0.06.10) = 1909,67(3.17) Chn V = 2000 m3.

(Cng thc ny thng c dung Tu u v M)

Trong :

Q: Lu lng nc thi

Y: H s nng sut x s dng cht nn cc i(mg bn hot tnh/ mg BOD5

tiu th)

c: Tui ca bn ( ly = 10 ngy)

So: BOD5 ban u = 400(mg/l)

S: BOD5 x l sau

X: Nng ca bn hot tnh

Kd: H s phn hy ni bo

Chn cc kch thc ca b: [2]

Kch thc ca b: BLH = 11,615,311.268(m)

Th tch b lc ny: V= BLH = 2000m3

Chn chiu cao d tr: hd = 0,3m

Chiu cao xy dng tng cng: Htc = H + hd = 11,568m

Xc nh thi gian lu nc trong b:

Thi gian lu ca nc trong b:

= VQ = 1909,465000 = 0,382ngy(3.18)

31

Tnh lu lng cn d (3.19)

- H s to cn BOD5( nng sut x dng cht nn): Y = Y1 + K = 0,461 + 0,06 10 = 0,2875 - Lng bn hot tnh sinh ra do kh BOD5 trong 1 ngy: P = Y Q (S S) 10(3.20)= 0,2875 5000 (400 28,03) 10= 534,64kg/ngy - Lng cn l lng sinh ra tnh theo tro ca cn:

P = 534,651 0,3 = 763,79kg/ngy(3.21) - Lng cn d hng ngy phi x ra:

Px=Lng cn l lng sinh ra-Lng cn l lng trong dng nc thi u ra

= Pxl Q SS 10-3 = 763,79 5000 50 10-3 = 513,79kg/ngy (3.22)

Xc nh lu lng bn hot tnh tun hon:

Mc ch ca vic tun hon bn hot tnh l duy tr nng bn hot

tnh l lng trong b aerotank p ng vi nhu cu x l t ra.

Lng bn tun hon c xc nh nh sau:

H s tun hon:

= QQ XX X = 28007000 2800 = 0,667(3.23) X: Nng bn hot tnh trong b aerotank

Xt: Nng bn hot tnh trong dng tun hon

Lu lng bn hot tnh tun hon: Qt = Q = 0,667 5000 = 3335m3/ngd

32

Lng bn x ra hng ngy

Q = V. X Q. X. X. = 1909,46 2800 5000 22,75 107000 10 = 60m Trong :

Qx: Lng bn x

V: th tch b

X: Nng bn hot tnh trong b

Qr: Lng nc thi u ra(xem nh nc cha trong bn khng ng k nn

ly lu lng nc thi u ra bng nc thi u vo = 5000m3)

Xr: Lng cn hu c bay hi u ra = 0,65 50 0,7 = 22,75mg/l (SSu ra = 50, gm 65% cn hu c, tro 0,3)

Xt: Lng cn hu c bay ra trong dng tun hon = 100000,7 = 7000m/l

Sau khi h thng hot ng n nh, lng bn x hu c ra hng ngy l:

(3.24) B = Qx Xlg 10-3 = 60 10000 10-3 = 600 kg/ngy Trong cn bay hi: B = 600 0,7 = 420 kg/ngy Cn bay hi trong dng nc x l i ra khi b: B = Qr Xr 10-3 = 5000 22,75 10-3 = 113,75 kg/ngy (3.25)

Tng lng cn hu c sinh ra: B + B = 420 + 113,75 = 533,75 kg/ngy (3.26) Trong :

Xlg: Nng bn y b lng t II v trong dng tun hon = 10000mg/l.

33

Kim tra chi tiu lm vic ca b: FM = St. X = 4000,3819.2800 = 0,374mgBOD mg. ngy (3.27) = S St. X = 400 28,030,3819.2800 = 0,3478 gBOD g. ngy

Trong :

t: Thi gian lu ca nc thi trong b aerotank

Xc nh lng oxy cn thit:

OC = Q (S S)f 1,42P = 5000 (400 28,07)0,68 1,42 534,65= 1975,57 kg ngy (3.28) Trong :

OC0: Nhu cu oxy theo l thuyt

f: h s chuyn ng t BOD5 sang BOD20

Px: Lng bn hot tnh sinh ra mi ngy

S0: Nng BOD5 ban u

S: Nng BOD5 sau b lng t II

Lng oxy cn thit trong iu kin thc t:

OC = OC CC C 11,024() 1= 1975,57 9,021.8,027 2 11,024() 10,8= 3605,6 kg ngy (3.29) Trong :

: H s chnh lc cng theo hm lng mui, i vi nc thi thng ly

=1

34

Cs20: Nng oxy ha bo ha trong nc sch ng vi nhit v cao

trm x l so vi b mt nc bin

Csh: Nng oxy ha bo ha trong nc sch 20oC

Cd: Nng oxy cn duy tr trong cng trnh

T: Nhit nc thi, chn T = 20oC

: H s iu chnh lng oxy ngm vo nc thi do nh hng ca hm

lng cn, cht hot ng b mt, loi thit b lm thong, hnh dng kch thc b,

c gi tr t 0,6 - 0,94. Chn = 0,8

Lng khng kh cn thit :

Q = OC fOU = 3205,6 0,680,028 1,5= 116775,4m ngy = 81094 l ph (3.30) OU: Cng xut ha tan oxy vo nc thi cu thit b phn phi tnh theo g

oxy cho 1m3 khng kh su ngp nc h = 1m, OU = 7g O2/m3.m

h: xu ngp nc. B su 4,3m, chn ngp nc h = 4m

f : H s an ton, thng t 1,5 2. Chn f = 1,5

Tnh, chn la thit b lm thong:[2,4]

Thit b lm thong trong b aerotank c ngha rt to ln, bi v cng sut

thit b, hiu qu lm vic ca b, h s s dng khng kh v cc chi ph vn hnh,

qun l u ph thuc vo cc yu t ny.

Chn thit b phn phi kh m nhn, dng a snh xp.

Chn ng knh a 0,25m khi c cng thi kh l qk = 300l/ph

S a phn phi kh:

N = Qq = 81094300 = 270,3a. chnN = 270a(3.31) B tr 12 nhnh phn phi kh dc theo chiu di, mi nhnh 18 a

35

Khong cch gia 2 nhnh phn phi l 1m

Khong cch gia a phn phi ngoi cng vi thnh b l 0,3m

Khong cch gia a phn phi lin tip trn cng mt nhnh l 0,9m

Hnh 3.2. S lp t h thng phn phi kh v chi tit a phn phi

ng knh ng phn phi:

D = 4 f = 4 Q v = 4 18 3005000 60 15 = 0,039m(3.32) Trong :

v: Vn tc kh thi vo trong ng, v = 10 15m/s [1,115]

Q: Tng lu lng kh qua 7 a trn mi nhnh

Chn D1 = 70mm ( ng knh ngoi 76mm)

Khi vn tc kh ng v = 9,1m/s

ng knh ng dn kh chnh:

D = 4 f = 4 Q v = 4 270 3005000 60 15 2 = 0,1m(3.33) Cho ng thp khng r D1 = 100mm ( ng knh ngoi 110mm)

36

Kim tra li vn tc kh chy trong ng: v = () = (,) = 85,98m/s(3.34)

Hnh 3.3. Hnh v chi tit b aerotank

Bng 3.8: Thng s thit k b aerotank:

STT Tn thng s n v S liu thit k

1 Th tch b m3 2000

2 Chiu su m 11,268

3 Chiu di m 11,6

4 Chiu rng m 15,6

5 Thi gian lu gi 9.167

6 Lng bn tun hon m3/ngy 3335

7 Lng bn x m3 60

8 S nhnh phn phi kh nhnh 12

9 S a phn phi kh a 270

37

3.1.3. B lng t II: [1]

- Chc nng:

B lng t II nhm tch cc bng bn sinh hc ra khi nc v c c

bn n nng nht nh phn di ca b bi tun hon li aerotank.

Yu cu ca b lng:

Phn nc trong nm pha trn tnh t mp mng thu xung n mt phn chia

thng ly ln hn 1,5(m) m bo chiu cao lng an ton.

Phn c c lm pha di phi c chiu cao cha lng cn di ra

trong cc gi cao im, cha lng cn tch li do h thng x l cn ngng lm

vic sa cha trong vi ngy v c thi gian c c v nn cn n nng

C mong mun.

- Tnh ton: t cng thc 3.35 n 3.43 [2,192]

Chn b lng kiu hng tm

Din tch b mt lng:

S = Q. (1 + ). CC. V = 208,33. (1 + 0,667). 400010000 0,34 = 408,57m(3.35) Q: Lu lng nc thi (m3/h)

Co: Nng cn trong b aerotank: C = X1 0.3 = 28000,7 = 4000mg/l(3.36) Ct: Nng cn trong dng tun hon = 1000mg/l

VL: Vn tc lng ca cn, ph thuc vo nng cn Ct v tnh cht ca cn,

thng phi tin hnh th nghim xc nh, tuy nhin trong iu kin khng th

xy b th nghim, c th tnh theo cng thc: V = V. e. = 7 e.. = 0,34m/h Vmax = 7m/h : Vn tc lng cci

38

CL = 0,5.CL = 5000mg/l K = 600 Din tch b nu k c phu thu nc trung tm S = 408,57 1,1 = 449,43m : = 4.

. 3,14 = 4.449,431.3,14 = 23,93(3.37) Chn = 24

ng knh phu thu nc: d = 0,25 D = 6m

Din tch phu thu nc: f = 5,94m2 ly trn l 6

Din tch vng lng ca b: SL = 449,43 6 = 443,43m2

Ti trng thy lc:

a = Q(1 + )S = 5000 (1 + 0,667)443,43 = 18,79 m m. ngy (3.38) Mng phn phi nc t ng trn c ng knh 0,8m ng knh b

Dmng = 0,8 24 = 19,2m

Chiu di mng thu nc

L = Dmng = 3,14 19,2 = 60,29m

Xc nh chiu cao ca b

Chn chiu cao ca b H = 4m

Chiu cao d tr trn mt thong h1= 0,3m

Chiu cao ct nc trong b 3,7m gm:

- Chiu cao phn nc trong h2 = 1,5m

- Chiu cao phn y chop c dc i = 2% v tm h = i = 0,02 = 0,24m (3.39)

39

Chiu cao cha bn phn hnh tr:

h4 = H h1 h2 h3 = 4 - 0,3 1,5 0,24 = 1,96m

Th tch phn cha bn

vb = S h4 = 449,43 1,96 = 880,88m3 (3.40)

Dung tch b lng

V = h S = 3,7 449,43 = 1662,89m3 (3.41)

Nc i vo b lng

Q1 = (1 + ) Q = (1 + 0,667) 5000 = 8335m3 (3.42)

Thi gian lng

T = VQ = 1662,898325 = 0,1997ngy = 4h47p(3.43)

Hnh 3.4. Hnh v b lng t II

40

Bng 3.9: Thng s thit k b lng t II:

STT Tn thng s n v S liu thit k

1 Din tch b mt lng m2 408,57

2 Din tch b mt lng k c mt phn

phi

m2 449,43

3 ng knh b m 24

4 ng knh mng phn phi nc m 19,2

5 ng knh phu thu nc m 6

6 Chiu cao tng cng m 4

7 dc y b - 0.02

8 Thi gian lng Gi 4 gi 47 pht

3.2. Thit b ph

3.2.1. Song chn rc [1]

- Chc nng:

Tch cc loi rc v tp cht th c kch thc ln trong nc thi trc khi

nc thi vo cc cng trnh x l pha sau. Vic s dng song chn rc s trnh

c hin tng tc nghn ng ng, mng dn v h hng bm.

- Tnh ton: t cng thc 3.44 n 3.48 [2,41]

Tnh song chn rc:

S lng khe chn rc:

n = Q kb h V = 0,091 1,050,016 0,3 0,8 = 24,88khe. chnn = 25(3.44)

41

Q: Lng nc thi ln nht (m3/s)

Chiu su lp nc trc thanh chn rc, chn h1 = 0,3

Vn tc trung bnh qua cc khe h, chn Vtt = 0,8m/s

H s thu hp dng ko = 1,05

Khong cch gia cc thanh, chn b = 0,016m

Chiu rng ton b thanh chn rc c tnh theo cng thc

Bs = (n- 1)d + bn = (25 - 1)0,01 + 0,01625 = 0,64m (3.45)

Chiu dy thanh chn, chn d = 10mm = 0,01m

Tng p lc qua thanh chn rc:

h = v 2p2g = 1,12 0,7 2 32 9,81 = 0,1678m. Chnh = 0,2m(3.46) Trong :

: H s tn tht p lc cc b, = Sin = 2,42

Sin60 = 1,12

: Yu t hnh dang thanh chn. Vi d =10 th = 2,42

: Gc nghing t thanh chn rc, chn a = 60o

v: Vn tc nc chy trc thanh chn rc

p: h s tnh n tang tr lc do thanh chn rc b bt kn bi vt thi, ly p = 3

Tnh mng t xong chn rc:

Gc m rng ca bung t thanh chn rc, ly bng 20o

Chiu di on m rng:

L = B B2 tg20 = 0,64 0,322 tg20 = 0,44(3.47) Bk: Chiu rng mng dn nc ti v ra khi song chn. Chn Bk = 0,32,

Bs = 0,138m

42

Chiu di bung t song chn rc, Ls ly khng ln hn 1m, chn Ls = 1

Chiu di on thu hp sau song chn L2 = 0,5.L1 = 0,22m

Chiu di mng t song chn:

L = L1 + L2 + Ls = 0,44 + 0,22 + 1 = 1,66m (3.48)

Hnh 3.5. Song chn rc

Bng 3.10: Thng s thit k song chn rc

STT Tn thng s n v S liu thit k

1 Song chn rc thanh 25

2 Chiu dy thanh m 449,43

3 Khong cch gia cc thanh m 0,01

4 Chiu rng ton b song chn m 0,64

5 Vt liu ch to Thp khn g

43

3.2.2. B lng ct [1]

- Chc nng:

Trng cn c ct s lm cho ng dn bn khng hot ng c, my bm

chng hng. i vi trm x l nc thi ln hn 100m3/ngy th xy b lng l

cn thit.

- Tnh ton: t cng thc 3.49 n 3.50 [1.147]

Chiu di b lng:

L = 1000 = 1,3 5000 0,2 0,2524,2 = 13,43(3.49) v: Tc chuyn ng ngang ca nc trong b lng ct, ly V = 0,2m/s

Hp: Chiu su phn lng, ly bng 0,25 1

Uo: ln thy lc ca ht ct theo ng knh( chn d = 0,25mm Uo =

24,2mm/s) [2,70]

m1: h s thc nghim tnh n ch thy lc v tc ri ca ht ct, ly n

= 1,3

Chiu rng b lng ct c xc nh theo cng thc: [2.70]

B = QV H = 0,01040,2 0,25 = 0,2m(3.50) Bng 3.11: Thng s thit k b lng ct STT Tn thng s n v S liu thit k

1 Chiu di m 13,43

2 Chiu rng m 0,2

3 Chiu su m 0,25

44

3.2.3. B iu ha lu lng [1]

- Chc nng:

Do tnh cht nc thi thay i tng gi sn xut v ph thuc vo tng loi

nc thi theo tng cng on, v vy cn phi xy dung b iu ha. B iu ha

c nhim v iu ha nc thi v lng v .

- Tnh ton: t cng thc 3.51 n 3.57 [2.82]

Th tch iu ha cht lng v lu lng nc thi W = W1 +Wmin (3.51) W1: Dung tch cn thit iu ha lu lng, xc nh tng t nh phng

php xc nh th tch b iu ha cha nc sch.

W = Q T1,4 = 0,04 1,051,4 = 89,3m(3.52) H s thc nghim 1,4

Chn thi gian iu ha lu lng l t = 2h

Wmin: dung tch nh nht iu ha cht lng W: Q T = 125m (3.53) Vy W = 142,3m3

Khng kh c a vo b qu h thng ng dn chm l vi ng knh

5mm

Khong cch cc ng phn phi, chn b = 1m

Chiu su lp nc trong b gi lu lng nh nht, Hmin = 2m

Chn s ng phn phi kh n = 9 ci

Chiu di b iu ha: L = n.b + b = 9.1 + 1 =10m (3.54)

Chiu rng b iu ha:

45

B = WH L = 1252 10 = 4,17m.ChnB = 4,2m(3.55) Chiu cao tng cng ca b iu ha

H = WB L = 142,34,2 10 = 3,43m.(3.56) Chn H = 3,5m Chiu cao d tr hd = 0,3m

Chiu cao xy dng tng cng: Hxd = H + hd = 3,5 + 0,3 = 3,8m (3.57)

Bng 3.12: Thng s thit k b iu ha lu lng

STT Tn thng s n v S liu thit k

1 Th tch m3 142,3

2 Chiu di m 10

3 Chiu rng m 4,2

4 Chiu cao cng tc m 3,5

5 Chiu cao xy dng m 3,8

3.2.4. B gom bn

- Chc nng:

Bn hot tnh t y b lng II s tp trung ti b gom bn. Bn t b gom 1

phn c tun hon tr li b aerotank phn cn li s a n my nn bn trc

em n sn phi.

- Tnh ton: t cng thc 3.58 n 3.62

Th tch ngn cha bn hon ton:

46

V = Q t = 3335 3024 60 = 69,48m(3.58) Trong :

Qt: lu lng bn tun hon = 3335m3

T: Thi gian lu bn trong b, chon t = 30 pht

Th tch ngn cha bn d:

V2 = Qt t = 51,9451= 51,945m3 (3.59)

Trong :

Qw: lng bn x hng ngy = 12m3/ngy

t: thi gian lu lng bn trong b, chn t = 1 ngy

Th tch tng cng ca b:

V = V1 + V2 =69,48 + 51,945 = 121,425m3 (3.60)

Chiu cao b 3m, d tr 0,3m

Chiu di v rng 6,36m

Chiu di ngn cha bn tun hon

L = VH B = 69,483.6,39 = 3,62m(3.61) Chiu di ngn cha bn d

L2 = L L1 = 6,36 3,62 = 2,74m (3.62)

Hnh 3.6. B gom bn

47

Bng 3.13: Thng s thit k b gom bn

STT Tn thng s n v S liu thit k

1 Chiu di b m 6,36

2 Chiu di ngn cha bn tun hon m 3,62

3 Chiu di ngn cha bn d m 2,74

4 Chiu rng b m 6,36

5 Chiu cao phn cng tc m 3

6 Chiu cao phn tng cng m 3,3

3.2.5. B nn bn [2]

- Chc nng:

Gim khi lng ca hn hp bn cn bng cch gn mt phn hay phn ln

lng nc c trong hn hp gim kch thc thit b x l, gim trng lng

vn chuyn n ni tip nhn, hn ch nc bn c th thm vo nc ngm bi

thi.

- Tnh ton: t cng thc 3.63 n 3.68 [2,127]

Lng cn ti trong b lng t I dn n b nn bn c xc nh theo

cng thc tnh hiu qu ca b lng t I:

G = Q SS E1000 = 5000 500 0,61000= 1500 kg ngaydem (3.63) Trong: SS0: 500m/l. Nng cht rn l lng b lngt I

48

EISS: 0,6. Hiu qu x l cht rn l lng b lngt I G2 = 513,79kg/ngaydem G = G1 + G2 = 1500 + 513,79 = 2013,79kg/ngaydem - Lng bn cc i dn n: Gmax: K G = 1,15 2013,79 = 2315,8585 ngay/dem (3.64)

K: H s khng iu ha ca bn hot tnh v lng cn thi ra t b, chn K

= 1,15.

- Din tch b mt nn bn:

F = Ga = 2315,858540 = 57,9m(3.65) - Din tch b nn bn nu them bung phn phi trung tm: Ftc = 1,2 F = 57,9 1,2 = 69,48m2 (3.66) - ng knh b nn bn:

D = 4 F

= 4 69,48

= 9,41m.ChnD = 9,5m(3.67) - Lng bn rt ra hng ngy:

Q = Gd C 1000 = 2315,85851,005 0,08 1000 = 28,8m(3.68)

49

Bng 3.14: Thng s thit k b nn bn

STT Tn thng s n v S liu thit k

1 Din tch b m 57,9

2 ng knh b m 9,5

3 Chiu cao phn cng tc m 3

4 Chiu cao phn lng m 3

5 Chiu cao tng cng m 6,3

3.2.6. Thit b kh trng [1]

- Chc nng:

Sau khi x l sinh hc, phn ln cc vi khun trong nc thi b tiu dit.

Nhng tiu dit ton b vi sinh vt , phi kh trng bng cch clo ha, ozon ha,

ip phn

- Tnh ton: t cng thc 3.69 n 3.73 [1.233]

Lng Clo cn thit kh trng:

Q = a Q1000 = 3 50001000 = 15 kg ngay (3.69) Q: Lng nc thi trong ngy

a: Nng Clo hot tnh yu cu, chon a = 3g/m3

Dung tch hu ch ca thng ha tan c tnh theo cng thc:

W = Q b p n = 15.100.1001000.2,5.20.2 = 1,5m(3.70)

Trong :

50

QCl: Lng Clo cn thit trong mt ngy

b: Nng dung dich clorua vi, b = 2,5%

p: Hm lng Clo hot tnh trong Clorua vi, p = 20%

n: S ln ha trn Clorua vi trong ngy m. Chon n = 2

Th tch tng cng ca thng ha tan tnh c th tch phn nng: Wtc = 1,15 W = 1,15 1,5 = 1,725m3 (3.71) Chn 2 thng ha tan, th tch ca mi thng l:

W = W2 = 1,7252 = 0,8628 = 0,9m(3.72) Th tch thng ha trn ly bng 40% th tch thng ha tan Wtr = 0,9 0,4 = 0,36m3 B tip xc, t = 40p

Th tch b tip xc:

W = T Q = 2 50003 24 = 138,89m(3.73) Kch thc b tip xc: 2 6,3 2

Bng 3.15: Thng s thit k thit b kh trng

STT Tn thng s n v S liu thit k

1 Th tch m3 138,89

2 Chiu di m 6,95

3 Chiu rng m 2

4 Chiu cao cng tc m 2

5 Chiu cao xy dng m 2,3

51

CHNG 4: THIT B PH TR

4.1. Tnh ng dn nc

Cng thc chung tnh:

D = 4 Q v

Trong :

Q: Lu lng nc thi

v: Vn tc nc chy trong ng

4.1.1. Cc ng dn nc chnh khi s dng bm [1]

Chn v = 2m/s

ng knh ng dn nc thi t b lng t I n b aerotank: [1,90]

D = 4.0,0578. 2 = 0,192m(4.1)

Chn st trng km c ng knh = 200 mm

Kim tra li vn tc nc chy trong ng:

v = 4. Q. D = 4.5000. (0,192). 24.3600 = 1,99 m s thaiukin(4.2)

ng knh ng dn nc thi t b aerotank sang b lng t II: [1,90]

D = 4.0,096. 2 = 0,25m(4.3) Kim tra li vn tc:

v = 4.8335. (0,25). 24.3600 = 1,96 m s thaiukin(4.4)

52

4.1.2. Cc ng dn nc chnh khng s dng bm [1]

Vn tc nc chy khi khng s dng bm. Chn v = 0,7m

= 4.0,05780,7. = 0,34(4.5) Kim tra lai vn tc: v = 4.5000

. (0,34). 24.3600 = 0,66 m s thaiukin(4.6) 4.2. Tnh ng dn kh [1]

Kh nn dng cung cp cho b iu ha v b aerotank

Lu lng kh tng cng: Q = Q1 + Q2 = 180+2700,30,6 = 5040 m3/h

=1,4 m3/s (4.7)

Trong :

Q1 = 180m3/h : Lu lng kh cung cp cho b iu ha

Q2 = 4860m3/h : Lu lng kh cung cp cho b aerotank

Vn tc kh trong ng dn: chn v = 12m/s

ng knh ng dn chnh:

= 4.1,412. = 0,38(4.8) Chn ng thp khng g c D = 200mm ( ng knh ngoi 219m)

Kim tra li vn tc

v = 4.5040. (0,38). 3600 = 12 m stha (4.9)

4.3. Tnh my nn kh [2]

Lu lng kh cung cp cho ton h thng:

53

Q = Q1 + Q2 = Q = Q1 + Q2 = 180+2700,30,6 = 5040 m3/h (4.10)

Trong :

Q1 = 180m3/h : Lu lng kh cung cp cho b iu ha

Q2 = 4860m3/h : Lu lng kh cung cp cho b aerotank

Xc nh p lc cn thit ca my thi kh:

H = h1 + h + Hn

Trong

h1: Tn tht p lc qua vi phun, chn h1 = 0,8m

h: Tn tht thy lc ca ng dn kh, chon h = 1m

Hn: su ngp nc ca vi phun trong b, chn Hn = 4,8m

Vy: H = 1 + 0,8 + 4,8 = 6,6m

p lc ca my nn kh

p = 10,33 + 6,610,33 = 1,64at(4.11) Cng sut my nn kh:

N = 34400. (, 1) 102 = 34400(1,64, 1)5040102.0,7.3600= 104(4.12) Chn 2 my nn khi lm vic lun phin cng sut l 104kW

54

CHNG 5: TNH GI THNH THIT B

Khi xc dinh hiu qu kinh t ca trm x l nc thi cn phi xc nh hiu

sut u t tnh cho 1 m3 nc thi hoc tnh cho mt ngi dn m h thng x l

nc phuc v. Song cung kho dn ra c gi tr tng qut do cc khon chi ph

lun thay i, do gi c bin ng mc thu khng n nh v iu kin a phng

u khch nhau. Chi phi u t cng ph thuc vo cng sut h thng thot nc

v cng ng trin khai.

Quy m cng nh s ngi s dng trm x l nc thi cng t th chi ph

xy dng v chi ph qun l cho mt ngi dn hoc mt m3 nc thi x l cng

tng. Chi phi vn hnh, qun l cc cng trnh x l nc thi l yu t cn tnh n

khi la chn dy chuyn cng ngh x l nc thi.

Kh xc nh chi ph qun l, vn hnh, ngoi hiu qu kinh t c th tnh

c cn phn quan trng khch l hiu qu mi trng khng tnh ton c

nhng c tc ng rt ln ti kinh t x hi, cn c quan tm ng mc.

y, ta tnh gi thnh ca cng trnh da vo bng gi thnh xy dng v chi

ph qun l vn hnh cc cng trnh x l nc thi theo nghin cu ca t chc

bo v mi trng M. [2.561]

Gi thnh xy dng cng trnh C ($)

Chi ph vn hnh qun l M( nm)

Thi gian hot ng ca cng trnh T (nm)

Gi thnh xy dng cng trnh khu hao theo nm:

= ($ )

55

Cng trnh C M T Cnm

X l s b bng b

lng ct v song

chn rc

B=674Q0.611

=122667.798

0.96Q + 25.038 =

4825.038

30 -

X l s b bng b

lng ct v khng c

thit b chn rc

C=531Q0.616 =

100846.32

0.96Q + 25.038 =

4825.038

30 -

X l s b bng

thit b chn rc

A = B - C =

21821.48

- 30 727.382

B lng t I -0.00002Q2 +

19.29Q +

220.389 =

96170.389

169Q + 11.376 =

845011.376

30 3205.679

B Aerotank 72Q + 368.043

= 360368.043

4.58Q + 36.295 =

22936.295

40 9009.2

B lng t II 2941Q0.609 =

526220.493

3.32Q + 5.842 =

16605.842

40 13155.512

Sn phi bn 89Q0.854 =

128324.739

-0.00002Q2 +

2.57Q + 80003 =

82353

20 6416.236

Bm bn 44.77Q +

323.702 =

224173.702

-0.000003Q2 +

5.2Q + 5733 =

25925

10 22417.37

B nn bn trong 177Q0.68 = -0.0000003Q2 + 50 1159.585

56

57979.286 0.18Q + 4136 =

5028.5

Cc cng trnh ph

khc

1438Q0.567 =

179918.109

-0.000003Q2 +

1.97Q + 57349 =

67124

50 3598.36

Tng - 1074637.089 - 59689.324

57

TI LIU THAM KHO

[1] Trinh Xun Lai, Tnh ton thit k cc cng trnh x l nc thi, NXB Xy

dng, 2000, 240tr.

[2] PGS, TS Hong Vn Hu, Thot nc v x l nc thi, NXB Khoa hc v

k thut.

[3] ng Trn Phng, Sinh thi v mi trng trong dt nhum, NXB Khoa hc

v k thut.

[4] Trn Hiu Hu, Trn c H, Hi, Cp thot nc, Nh xut bn khoa

hc v k thut.

[5] Nhiu tc gi, S tay ti liu k thut, Tng cc mi trng.

[6] Nguyn Trung Thu, Vt liu dt , i hoc Bch Khoa H Ni, 1990.

[7] Trn Vn Nhn, Ng Th Nga, Gio trnh cng ngh x l nc thi, NXB

Khoa hc k thut, 1999.

[8] Hong Hu, X l nc thi, NXB Xy Dng, 1996.

[9] . Nguyn Cng Ton, Cng ngh nhum v hon tt, NXB i hc Quc gia

Tp.H Ch Minh, 2005.

[10] PGS.TS Hong Vn Hu, PSG.TS Trn c H - Thot nc tp II- X l

nc thi NXB Khoa hc v k thut H Ni, 2002.

Cc websites tham kho:

[1]. Website Cc Mi trng:http://www.nea.gov.vn/

[2]. Website Trung tm sn xut sch hn Vit Nam: http://www.un.org.vn/vncpc/