ky thuat moi truong-dh11hd 336tr.pdf

K THUT MI TRNG

CHNG I-CC KHI NIM V MI TRNG

1.1 Mi trng : l tp hp tt c cc thnh phn vt cht bao quanh ta,

c hnh thnh do cc qu trnh t nhin hoc c to ra bi con ngi,

c kh nng tc ng n s tn ti v pht trin ca sinh vt.

Mi trng t nhin: thch quyn, thy quyn ,kh quyn v sinh quyn

Mi trng nhn to: ng rung, vn tc, cng vin, thnh ph, cc

cng trnh vn ha, cc nh my sn xut cng nghip..

S quan h tng quan x hi v mi trng


1.1.1.Kh quyn

L lp kh bao ph xung quanh b mt Tri t, c khi lng

5,2x1018 kg. Lp kh quyn gn mt t c vai tr ht sc ln

lao i vi s sng trn tri t.

Cung cp O2 v CO2 cn thit duy tr s sng trn Tri t, ngn chn cc tia t ngoi gn (=300 nm), cho cc tia trong vng kh kin tia trng thy (=400-800 nm), tia hng ngoi gn (=2500 nm), v sng radio (= 0,1 - 40 m) i vo Tri t.

Gi cn bng nhit lng ca Tri t (thng qua qu trnh hp th tia t ngoi pht x t mt tri v phn x tia nhit t Tri t).

L mi trng vn chuyn nc t i dng vo t lin, tham gia vo qu trnh tun hon nc.


Cu trc kh quyn


a. Tng i lu

Cha 70 % khi lng kh quyn

cao: 0 11 km. cao tng i lu c th thay i vi km, t 8 km ( cc cc) n khong 18 km ( xch o).

Cng ln cao nhit khng kh cng gim (nhit gim dn t +400C st mt t xung cn -500C nh tng i lu).

Thnh phn khng kh ch yu l N2, O2, CO2 v hi nc.

Lp tm dng (lp chuyn tip) nm ngn cch tng i lu v tng bnh lu.

Chiu dy khong 1 km.

nh du s nghch chuyn nhit t m sang dng.


b. Tng bnh lu

- cao khong 11 - 50 km.

- Nhit khng kh tng (t khong -500C tng di tng

dn v t n khong -20C nh).

- Thnh phn khng kh ch yu l: O3, N2, O2 v mt s gc

ha hc khc

- cao khong 25-30 km tn ti mt lp khng kh rt giu

kh zn, cn c gi l tng zn.

- Tng zn c chc nng nh mt l chn ca kh quyn.


c. Tng trung lu

- cao dao ng t 50 - 85 km.

- Nhit tng m (t khong -20C tng di tng m n

khong -920C)

- Thnh phn cc cht ch yu l: O2+, NO+, O+ v N2.

- Tng trung quyn ngn cch vi tng nhit bi mt lp kh

mng (khong 1 km).


d. Tng nhit lu

- cao khong 85 km n 500 km.

- Nhit tng ny tng dn theo chiu cao (t -920C n

+12000C)

- Cc phn t, nguyn t b ion ha thnh cc ion O2+, O+,

NO+, e-, NO2-, NO3-,

- Lp chuyn tip gia tng nhit quyn v tng nhit ngoi.


e. Tng ngoi

- cao t 500 km ln n 2000 km.

- C mt cc ion O+, He+ (1500km)

- Nhit tng ny tng rt nhanh, n khang 17000C.


f. S thay i nhit theo cao


g. S thay i p sut theo cao


1.1.2 Thy quyn

Thy quyn bao gm cc dng ngun nc trn Tri t nh: bin, h, sng, sui, nc ng bng hai cc Tri t, nc ngm.

Nc ng vai tr quan trng trong sinh hot, sn xut cng nghip. Trong cng nghip, ngi ta s dng nc lm nguyn liu v ngun nng lng, lm dung mi, lm cht ti nhit v dng vn chuyn nguyn vt liu...

Nc t nhin l nc m cht lng v s lng ca n c hnh thnh di nh hng ca cc qu trnh t nhin khng c s tc ng ca con ngi.


1.1.2 Thy quyn

Phn b khi lng nc trn Tri t


1.1.3 a quyn

Bao gm lp v tri t c dy t 70 - 100 km trn phn lc

a v 20 - 30 km di y i dng.

su khong 16 km con ngi c th khai thc cc nguyn

liu trong v tri t.

Lp v tri t c tnh cch nhit, bn di l lp bao dy

2900 km trng thi nng chy trn 10000C, trong cng l lp

nhn dy 3400 km, c nhit 55000C.


1.1.4 Sinh quyn

Sinh quyn gm tt c nhng thnh phn ca ba mi trng k

trn c tn ti s sng v c lin quan tc ng tng h gia

cc thnh phn mi trng kh quyn, thy quyn, a quyn.

Khc vi kh quyn, thy quyn, a quyn, sinh quyn khng

c gii hn r rt v n nm trong c ba thnh phn mi trng

k trn v khng hon ton lin tc v s sng ch tn ti trong

iu kin nht nh.


1.2 nhim mi trng

S nhim l qu trnh chuyn cht thi hoc nng lng vo

mi trng n mc c kh nng gy tc hi n sc khe con

ngi, vt liu v s pht trin ca sinh vt.

Cc tc nhn gy nhim bao gm cht thi dng rn, lng

hoc kh v cc dng nng lng nh nhit , ting n, phng

x

Tiu chun cht lng mi trng l nng gii hn hoc ti

a cc cht nhim cho php trong mi trng xung quanh

hoc c php thi ra mi trng


1.2 nhim mi trng

Qu trnh vn chuyn cc cht nhim


1.3 Cc cht v ngun nhim c bn

a. Khng kh: Cc cht nhim khng kh ch yu l oxit cacbon, oxit lu hunh, oxit nito, hydrocacbon v bi cng nghip. Cc ngun nhim chnh l giao thng, cng nghip.

b. Nc: Nc thi ca cc nh my cng nghip v nng nghip thi vo ngun tip nhn nh sng, h, bin. Cc cht gy nhim nc rt a dng bao gm: cc cht hu c d phn hy, ha cht c, cht rn l lng, cc cht dinh dng ( Nito, photpho), cc vi khun gy bnh, nhit , cc kim loi nng, du v cc sn phm du kh.

c. t: S nhim mi trng t ch yu l do thuc tr su dit c, ha cht bo v thc vt, khai thc khong sn, ph rng, cht thi rn chn lp khng hp v sinh nhim mn, nhim phn


1.4 Qun l cht lng mi trng:

a. Cc cng c php l: lut, chnh sch, chin lc, quy nh, tiu chun mi trng, cc h thng qun l cht lng mi trng, ISO, cc tha thun da trn s tnh nguyn v nh gi tc ng mi trng.

b. Cc cng c kinh t: thu v ph mi trng, giy php cht thi c th mua bn c hay Cota nhim, k qu mi trng, tr cp mi trng n b thit hi.

c. Cng c gio dc, nng cao nhn thc cng ng

d. Bin php k thut: hon thin cng ngh sn xut v thu hi cht thi, thnh lp cc quy trnh da trn cng ngh c t hoc khng c cht thi

CHNG II- NHIM KHNG KH V CC K

THUT X L C BN

nhim khng kh c th nh ngha nh sau:

- nhim khng kh l qu trnh thi cc cht nhim vo mi

trng lm cho nng ca chng trong mi trng vt qu

tiu chun cho php, nh hng n sc khe con ngi, cc

ng thc vt, cnh quan v h sinh thi

- nhim khng kh l s xut hin ca cht l hoc c s bin

i quan trng trong thnh phn ca khng kh lm cho n

khng sch, bi, c mi kh chu, lm gim tm nhn


THUT X L C BN

2.1 Cc phng php x l kh thi

2.1.1 Ngun gc nhim khng kh

Theo c tnh hnh hc

Theo ngun gc pht sinh


THUT X L C BN

2.1 Cc phng php x l kh thi

2.1.1 Ngun gc nhim khng kh

Theo c tnh hnh hc

Ngun im: ng khi

Ngun ng: tuyn gtvt

Ngun vng: khu cng nghip tp trung, ng t ni thnh,

nh ga.

Da vo ngun gc pht sinh:

Ngun t nhin

Bi t

Chy rng, ng c, du la

Hot ng ca ni la: tro bi, kh c (SO2,CH4, H2S)

Bi v tr

S phn hy t nhin ca cc cht hu c,

xc cht ng thc vt, to nhiu mi hi v kh c.

S pht tn ca phn hoa, bi mui bin, ..

Ngun nhn to

Ngun c nh: ng khi, nh my, cc khu cng nghip

Ngun di ng: giao thng vn ti

NGUN NHN TO

NGUN C NH NGUN DI NG

2.1.2 Phn loi cht thi trong kh thi cng nghip

Da vo trng thi vt l:

Rn: Bi, khi..

Lng: sol lng/kh nh sng m..

Kh v hi: COx, NOx, SO2..

Vt l: n, nhit, phng x..

Da vo kch thc ht:

Phn t (hn hp kh-hi)

Aerosol ( gm cc ht rn, lng)

Bi: =5-50m

Khi: =0,1-5m

Sng: =0,3-5m

STT Ngnh sn xut Cc cht nhim c trng

Nh my nhit in, l nung, ni hi t bng nhin liu

Bi, SOx, NOx, COx, hydrocacbon aldehyt.

Ch bin thc phm . Sn xut nc . Ch bin ht iu

Bi, mi n, NH3 (nu dng gas ammoniac) Bi, mi hi, cc phenol

Thuc l Bi, mi hi, nictin

Dt, nhum Bi, hp cht hu c

Giy Bi, mi hi

Sn xut ha cht . Acid sunfuric

. Superphotphat

. Amoniac

. Keo, sn, vecni . X bng, bt git . Lc du

SOx

Bi, HF, H2SiF6 , SO3 NH3

Bi, hp cht hu c bay hi Bi, kim Cc hydrocacbon, bi, COx , SOx , NOx .

Snh s, thu tinh, vt liu xy dng Bi, COx , HF

Luyn kim, l c Bi, SO2 , COx , NOx ,

Nha, cao su, cht do Bi, mi hi, dung mi hu c, SO2

Thuc tr su Bi, mi hi, dung mi hu c, TBVTV

Thuc da Mi hi (do cc hp cht sunlfua, mecaptan, amoniac)

Bao b Mi hi ca cc dung mi hu c, bi

Kh thi giao thng Bi, ch, NOx , SOx , COx , hp cht hu c

Kh thi do t phc v sinh hot Bi, mi hi, COx.

2.1.3 Cc phng php x l kh thi

KH THI

X l bi X l sng m v git lng

Thit b ra kh:

Bung phun, trn, m,

mm, va p qun

tnh, ly tm, vn tc ln

Pp t Pp in Pp kh

Lng trng lc

Lng qun tnh

Lng ly tm

Lc: vi, si, s..

Lc in

kh

Lc in t

X l tp cht kh

X l tp cht hi

Pp hp th

Pp hp ph

Pp xc tc

Pp nhit

Pp ngng t

Thp hp th:

mm, m, mng, phun

Thp hp ph vi lp tnh,

ng v tng si

Thit b phn ng

L t Thit b ngng t

2.1.4 Tc hi ca bi:

Bi sinh ra trong khng kh s gy rt nhiu tc hi cho con ngi,

ng vt v thc vt, nh hng n cnh quan mi trng.

1. Tc hi i vi con ngi v ng vt

2. Tc hi i vi thc vt

3. Tc hi i vi vt liu

4. Tc hi i vi cnh quan mi trng

2.1.5 Cc bin php phng chng bi

Bi trong sn xut gy nhiu tc hi cho sc khe ngi cng nhn,

a s cc bnh phi nhim bi u l nhng bnh nng, pht hin

kh, cha c thuc cha, cho nn vn phng chng bi phng

bnh phi l vn rt quan trng, bin php phng tch cc l

chng bi ni lm vic

1. Bin php k thut

2. Bin php phng h cc nhn

3. Bin php y t

2.2 X L AEROSOL (BI, KHI, SNG)

Khi nim chung v bi

-Cc phn t cht rn th ri rc (vn) di tc dng ca cc

dng kh hoc khng kh, chng chuyn thnh trng thi l lng

v trong nhng iu kin nht nh chng to thnh th vt cht

m ngi ta gi l bi.

Bi gm hai pha: pha kh v pha rn ri rc.

Ht Bi c kch thc t nguyn t n nhn thy c bng

mt thng, c kh nng tn ti dng l lng trong thi gian

di ngn khc nhau.


Phn loi

Theo ngun gc;

Theo kch thc ht bi;

Theo tc hi;


nhim bi do tiu th cng nghip


nhim bi do giao thng vn ti


Cc phng php x l:

X l bi bng phng php kh

X l bi bng phng php t

Thit b lc in

2.2.1 X L BI THEO PHNG PHP KH

-Thit b thu hi bi kh hot ng da trn cc

c ch lng khc nhau: trng lc, qun tnh, ly

tm. Cc thit b ch to v vn hnh n gin,

c p dng ph bin trong cng nghip. Tuy

nhin, hiu qu thu bi khng cao, thng ng

vai tr x l s b.

-Thit b lc bi kh: khi cho kh qua vch ngn

xp, cc ht rn c gi li cn kh i xuyn qua

n hon ton

Nguyn l hot ng: S lng bi bng bung lng l to iu

kin trng lc tc dng ln ht bi thng lc y ngang ca

dng kh. Trn c s ngi ta to ra s gim t ngt lc y

ca dng kh bng cch tng t ngt mt ct ca dng kh chuyn

ng. Trong thi im y, c ht bi s lng xung

Trong thi gian kh i qua thit b, cc ht bi di tc dng ca

lc hp dn lng xung pha di v ri vo bnh cha hoc c

a ra ngoi bng vt ti hay bng ti.

A. BUNG LNG BI

p dng vi ht bi c kch thc ln, dng kh chuyn

ng vi vn tc nh (< 1 2 m/s)

Cu to ca bung lng bi

oBung lng bi c lm t gch, b tng ct thp,hoc

thp.

oBung lng bi l mt khng gian hnh hp c tit din

ngang ln hn rt nhiu ln so vi tit din ng ng

dn

oTrn bung lng c ca lm v sinh hay ly bi ra

ngoi.

A. BUNG LNG BI

Cc loi bung lng

a) Bung lng bi n gin

b) Bung lng vi vch ngn

c) Bung lng nhiu tng

Bung lng nhiu tng

Bung lng nhiu tng

u im

Do chia thnh nhiu tng nn kch thc

chnh ca bung lng c thu gn, t chim

din tch nhng vn lc c mt lu lng

kh ln vi hiu sut lc cao.

Nhc im

Kh dn dp v sinh khi c bi bm

trn cc tng.

A. BUNG LNG BI

Lng bi th, d ht >40 m, tuy vy cc ht bi nh hn vn gi c

li bung lng

Hiu sut(50-60)%

u im:

-Chi ph u t v vn hnh thp.

-Kt cu n gin.

-S dng x l kh thi c nng bi cao cha cc ht bi c kch

thc ln:l vi, l t v cc nh my ch bin thc n gia sc.

-Vn tc di chuyn ca dng kh trong TB nh ,khng gy mi mn

thit b.

Nhc im:

-Phi lm sch th cng nh k

-Cng knh, chim 1 din tch khng gian ln

-Ch thu c cc ht bi c kch thc tng i ln

A. BUNG LNG BI

Cch nng hiu qu ca qu trnh lng

Tng din tch y ca bung lng. V vy trong

thc t bn trong cc bung lng ngi ta c th t

nhiu sn nm ngang hoc nghing, khong cch

gia chng khong 100 300mm.

Khi cc ht bi c kch thc t 32- 40 m s

c gi li trong bung lng, cn cc ht c kch

thc 5 m th kh nng thu hi l bng khng.

B. THIT B LNG QUN TNH

Nguyn l c bn c p dng ch to thit b XL

bi kiu qun tnh l lm thay i chiu hng chuyn

ng ca dng kh mt cch lin tc, lp i lp li bng

nhiu loi vt cn c hnh dng khc nhau.

Khi dng i hng chuyn ng th bi do c sc

qun tnh ln s gi hng chuyn ng ban u ca

mnh v va p vo cc vt cn ri b gi li hoc

mt ng nng v ri xung y thit b.


Nguyn l hot ng: Khi t ngt thay i hng chuyn ng ca dng

kh, cc ht bi di tc dng ca lc qun tnh tip tc chuyn ng theo

hng ban u ca mnh v va p vo vt cn ri gi li hoc mt ng

nng v ri xung y thit b.

Kh nng lng cao hn bung lng.

Hiu sut (65-80)% i vi ht bi c d-25-30m.

Cc loi thit b lng bi qun tnh:

a. C vch ngn

b. Vi ch quay kh nhn

c. C vt cn


Thit b l xch: Cc thit b ny c dy l chn hoc cc vng chn. Kh i qua

mng chn, i hng t ngt, cc ht bi do qun tnh chuyn ng theo hng

c tch ra khi kh hoc va p vo cc tm phng nghing, lng trn ri ri

xung dng kh bi.

im yu ca l xch l s mi mn cc tm chn khi nng bi cao v c th

to thnh trm tch lm bt kn mt sng. Nhit cho php ca kh thi ph thuc

vo vt liu lm l chn, thng khng qu 450-600 C

C.CYCLONE

Thit b cyclon c ng dng rng ri trong

cng nghip c hiu qu cao khi kch thc ht

bi >5 m.

Thu hi bi trong cyclon din ra di tc dng

ca lc ly tm.

Nguyn l hot ng:

Dng kh nhim bi c a vo phn trn

ca cyclon. Thn cyclon thng l hnh tr c

y l hnh chp ct. ng dn kh bn vo

thng c dng khi ch nht, c b tr theo

phng tip tuyn vi cyclon.

Kh vo cyclon thc hin chuyn ng xon c,

dch chuyn xung di v hnh thnh dng

xoy ngoi. Lc , cc ht bi di tc dng

ca lc ly tm, vng vo thnh cyclon. Tin gn

y chp, dng kh bt u quay ngc tr li

v chuyn ng ln trn hnh thnh dng xon

trong.

C.CYCLONE

Ngn Thu kh

Bung

hnh tr

Bung

hnh chp

Kh bi

Bung lng bi

Thn cyclon

Kh sch

Thu bi

Khng kh

Bi

Kh bi

c. Cyclone

Trong cng nghip, cyclon c chia lm hai nhm: hiu

qu cao v nng sut cao. Nhm th nht t hiu qu cao

nhng yu cu chi ph ln, cn nhm th hai c tr lc nh

nhng thu hi cc ht mn km hn.

Trong thc t, ngi ta ng dng rng ri cyclon tr v

cyclon chp (khng c thn tr). Cyclon tr thuc nhm nng

sut cao, cn cyclon chp thuc nhm hiu qu cao.

C.CYCLONE

u im:

Khng c phn chuyn ng tng bn ca thit b;

C th lm vic nhit cao ( n 500 C);

Thu hi bi dng kh;

Lm vic p sut cao;

Nng sut cao, r;

C kh nng thu hi vt liu mi mn m khng cn bo v b mt cyclon;

Ch to n gin;

Nhc im

Hiu qu vn hnh km khi bi c kch thc nh hn 5 m;

C.CYCLONE

Cc dng cyclone:

a. Cyclone n: cyclone n l thit b hon chnh hot ng c lp v c

nhiu dng khc nhau nh dng hnh tr, dng cn. Vic s dng loi no

l ty thuc vo c tnh ca bi v yu cu x l.

b. Cyclone t hp ( nhm): l thit b lc bi gm mt s lng ln cc n

nguyn cyclone mc song song trong mt v c chung ng dn kh vo,

kh ra, thng cha bi.

C hai cch a dng kh vo cyclon to ra chuyn ng xoy l dng

tip tuyn v dng dng trc


d. Thit b lc bi kh

Thit b lc kh c s dng rt ph bin cho cc loi bi mn, kh

kh tch khi khng kh nh lc qun tnh v ly tm.

Nguyn l:

a dng khng kh ln bi i xuyn qua lp vt liu lc (vch

ngn xp), cc ht bi s b gi li trong lp vt liu lc, khng kh

sch i qua lp vt liu lc v c thi ra ngoi.

Trong qu trnh lc bi, cc ht bi kh tch t trong cc l xp

hoc to thnh lp bi trn b mt vch ngn v tr thnh mi

trng lc i vi cc ht bi n sau.

Tuy nhin, bi tch cng nhiu lm cho kch thc l xp v

xp chung ca vch ngn cng gim, v vy sau mt thi gian lm

vic no cn phi ph v v loi lp bi ra.

Nh vy, qu trnh lc bi phi kt hp vi qu trnh phc hi vt

liu lc


d. Thit b lc bi kh

Nguyn l:

Lc bi l a dng khng kh ln bi i xuyn qua lp vt liu lc

(vch ngn xp), cc ht bi s b gi li trong lp vt liu lc,

khng kh sch i qua lp vt liu lc v c thi ra ngoi.

Trong qu trnh lc bi, cc ht bi kh tch t trong cc l xp

hoc to thnh lp bi trn b mt vch ngn v tr thnh mi

trng lc i vi cc ht bi n sau.

Tuy nhin, bi tch cng nhiu lm cho kch thc l xp v

xp chung ca vch ngn cng gim, v vy sau mt thi gian lm

vic no cn phi ph v v loi lp bi ra.

Nh vy, qu trnh lc bi phi kt hp vi qu trnh phc hi vt

liu lc


d. Thit b lc bi kh

Thit b lc chia thnh ba loi:

- Thit b tinh lc: hiu qu cao, thu hi bi c hi c bit, cng

nh siu lc khng kh. Vt liu lc khng c phc hi. Nng

u vo thp 99%, vn tc lc

THIT B LC MNG-LC TI

Nguyn l:

Dng kh v bi c chn bi mng hoc ti lc, ti ny c khe nh cho

cc phn t kh i qua d dng nhng gi li cc ht bi.

Khi lp bi dy ngn cn lng kh i qua th ngi ta tin hnh rung

hoc thi ngc thu hi bi v lm sch mng.

u v nhc im

u im: Hiu sut lc cao ( ln n 99%), ph hp vi cc loi bi c

ng knh nh.

Nhc im: gi thnh v qun l cao, bn ca thit b lc bi thp v

thng dao ng theo m

Cc loi thit b lc mng-lc ti

Thit b lc vi

Thit b lc si

Thit b lc ht

MT S THIT B LC TI VI TRN TH TRNG

THIT B LC VI- THIT B LC BI KIU NG

TAY O

Cc thit b ny ph bin nht, c vt liu lc dng tay o hnh tr c gi cht

trn li ng v c trang b c cu r bi.

Mi ngn c t (8-15)ti vi hoc nhiu hn

Mi TB khng vt qu 10-12 ngn

ng knh ng tay o D=120-300(mm)

khng vt qu 600 (mm)

Chiu di ti L=2200-3500(mm)

T l gia D/L=(16-20):1

Cc phng php ti sinh vi lc:

- S rung lc

- Thi ngc vt liu lc bng kh sau x l hoc dng khng kh sch

THIT B LC BI KIU NG TAY O

Nguyn l hot ng:

Giai on 1: Khi vi lc cn sch, cc ht bi lng trn cc lp xp

nm trn b mt si v gia cc si. giai on ny hiu sut lc

bi cn thp.

Giai on 2: Khi c mt lp bi bm trn b mt vi, lp bi

ny tr thnh mi trng lc bi th 2. Hiu sut lc bi giai

on ny rt cao.

Giai on 3: sau mt thi gian lm vic , lp bi bm trn vi s

dy ln lm tng tr lc ca thit b, v vy phi lm sch vi lc.

Sau khi lm sch vi lc vn cn mt lng ln bi nm gia cc

x, cho nn trong giai on 3 ny hiu sut lc vn cn cao.

Thit b lc bi kiu ng tay o(tt)

Vi lc phi tha mn cc yu cu sau:

- Kh nng gi bi cao;

- C kh nng cho kh xuyn qua ti u;

- Bn c, nhit, chu c n mn ha hc;

- C kh nng ti sinh;

- Gi thnh thp;

Cc vt liu lc hin c khng tha mn

tt c cc tnh cht nu trn,

nn trong tng trng iu kin c th

phi tin hnh la chn chng.

Thit b lc bi kiu ng tay o(tt)

Vt liu lc ph bin nht l:

- Vi len: kh xuyn qua ln, m bo sch n nh v d phc hi, khng

bn ha hc v nhit.

- Vi tng hp: bn nhit v ha, gi r. Trong mi trng axit bn cao,

trong mi trng kim bn gim

- Vi thy tinh: bn nhit 150-350oC, c ch to t thy tinh nhm

silicat khng kim hoc thy tinh magezit

- Vi bng: tnh lc tt, gi thp, khng bn ha hc v nhit, d chy v cha

m cao

.

VT LIU LC BI

a) TB lc bi ng tay o nhiu ngn, gi bi

bng c cu rung v thi kh ngc

chiu:

1- bunke; 2- c cu rung gi bi; 3- ng

gp vo; 4- ng dn kh cha bi i vo b

lc; 5- n nguyn ang thc hin qt gi

bi; 6- van; 7 khung treo cc chm ng

tay o; 8- van thi kh ngc gi bi;

9- ng dn kh sch thot ra

b) TB lc bi ng tay o c khung lng

v h thng pht khng kh nn

kiu xung lc gi bi

1- van in t; 2- ng dn khng kh nn;

3- vi phun; 4- dng khng kh nn;

5-hp iu khin t ng qutrnh

hon nguyn (gi bi); 6 - ng tay o;

7- khung lng; 8 phu cha bi

2.2.2 PHNG PHP T

Nguyn l: da vo s tip xc gia dng kh mang bi vi cht lng, bi trong

dng kh b cht lng gi li v thi ra ngoi di dng cn bn.

u im:

- D ch to, gi thnh thp nhng hiu qu lc bi cao hn phng php kh

- C th lc c bi d

PHNG PHP T (TT)

Qu trnh thu hi bi theo phng php t da trn s tip xc ca

dng kh bi vi cht lng, c thc hin bng cc bin php c bn

sau:

- Dng kh bi i vo thit b v c ra bng cht lng. Cc ht bi

tch ra khi kh nh va chm vi cc git lng.

- Cht lng ti t b mt lm vic ca thit b, cn dng kh tip xc

vi b mt ny. Cc ht bi b ht bi mng nc v tch ra khi dng

kh.

- Dng kh bi c sc vo nc v b chia ra thnh cc bt kh. Cc

ht bi b dnh t v loi ra khi kh.

Do tip xc gia dng kh nhim bi vi cht lng hnh thnh b mt

tip xc pha. B mt ny bao gm cc bt kh, tia kh, git lng v

mng lng.

PHNG PHP T (TT)

Thit b lc bi kiu t thng c th chia thnh cc loi sau

y ty thuc vo nguyn l hot ng ca chng:

- Bung phun- thng ra kh rng;

- Thit b ra kh m( thp m);

- Thit b lc bi ( ra kh) vi lp ht hnh cu di ng;

- Thit b ra kh venturi;

- Thit b lc bi kiu t di tc dng va p qun tnh

A. Bung phun- thng ra kh rng

Nguyn tc hot ng

Dng kh mang bi i vo thit b t di qua sn

phn phi ln trn, dng nc c phun di dng

ht nh t trn xung. Khi hai cht tip xc nhau,

bi trong dng kh b cun theo nc i xung di,

cn kh sau khi tch bi, qua b phn chn nc tch

c hi nc thot ra ngoi u thit b.

Cu to:

1.V thit b;

2. Vi phun nc.

3. Tm chn nc.

4. B phn hng dng

v phn phi kh.

A. Bung phun- thng ra kh rng

c im:

+ Yu cu vn tc dng kh vo thit b trong khong (0,6 1,2) m/s i

vi thit b khng c b tch git v khong 5-8m/s i vi thit b c

b tch git

+ Hiu sut x l ph thuc vo cng phun nc v vn tc dng

khng kh chuyn ng trong thit b.

+ Cu to thit b n gin, gn, d ch to.

+ Vn hnh d.

+ Hiu sut x l kh cao:80-90%, i vi bi c kch thc d 10m

Phm vi p dng:

Thit b ny c s dng ph bin lc bi t trong kh thi ng thi

lm ngui kh.

B.Thit b ra kh m( Thp m)

Cu to

Thit b kh bi c lp m rng c ti nc cn gi l thit b (thp) ra kh hoc

scrubber, gm mt thng tit din trn hoc ch nht bn trong c cha mt lp

m bng vt liu rng v c ti nc

Nguyn tc hot ng:

Kh i t di ln xuyn qua lp vt liu rng,

khi tip xc vi b mt t ca lp vt liu

rng bi s bm li cn kh sch thot ra

ngoi. Mt phn bi s b nc cun tri xung

thng cha vc x ra di dng bn cn.

nh k ngi ta thay ra lp vt liu rng.

Thp ra kh Scrubber dng ng


c im

+ Vt liu rng thng dng cc loi khu c hnh dng khc nhau lm bng s, thy

tinh, nha

+ Cu to thit b n gin.

+ Hiu sut x l cao hn so vi thp ra kh rng (90% )i vi cc ht c d > 2 m.

+ Tr lc thit b ln.

+ Phi nh k thay ra lp vt liu rng.

V vt liu rng, ngi ta thng dng cc loi khu c hnh dng khc nhau, lm

bng kim loi mu, s hoc nha

1: Khu Raschig; 2: Khu c vch ngn;

3: Khu c vch ngn ch thp;

4: Khu Pall-c vch ngn v ca s;

5- Khu Berl ( kiu yn nga);

6: Khu Intalox


Ngoi loi thp phun nc kiu ng chuyn ng ngc chiu ca kh v

nc nh trn, ngi ta cn ch to loi thit b phun c lp m rng kiu

nm ngang . Cu to ca loi thit b ny cho php lm vic vi vn tc kh ln

hn so vi thit b thng ng (c th t 10 m/s) nh kch thc ca loi

thit b ny s gn nh hn.

Thp ra kh Scrubber (dng ngang)

D. Thit b lc bi (ra kh) vi lp ht hnh cu di ng

Nguyn tc hot ng:

Kh mang bi c a vo thit b t di ln.

Dng kh a vo ny lm cho cc ht

hnh cu chuyn ng hn lon trong

trng thi l lng, bi trong kh va p

vo cc ht hnh cu tch khi dng kh.

Nc c phun t trn xung cun theo

cc ht bi to thnh cn bn c dn ra

ngoi x l.

Thit b lc bi vi lp ht hnh cu di ng

1. Tm chn c l hoc li.

2. Ht cu. 3. Tm chn c l hoc li.

4. Vi phun nc.5. Tm chn nc.

D. Thit b lc bi (ra kh) vi lp ht hnh cu di ng

Cu to

Vt liu ch to ht hnh cu l nha, cao su hoc thy tinh. Ht rng

hoc c, khi lng ring ca ht cu khng c vt qu khi lng

ringca nc m bo cho cc ht hnh cu chuyn ng mt cch

t do trong hn hp kh nc bn trong thit b.

c im:

+ Hiu sut lc bi vi lp ht hnh cu di ng c hiu sut x l bi kh

cao.

+ Vn tc dng kh vo cho php trong khong (5-6) m/s v t l nc

kh l (0,5-0,7) l/m3.

+ ng knh thch hp ca cc ht hnh cu l d = (20-40) mm.

+ Trng lng n v ca cc ht hnh cu: = (200-300) kg/m3.

Phm vi p dng:

Thit b ny thng c p dng x l bi trong cc ngnh cng

nghip

e. Thit b ra kh va p qun tnh

Nguyn tc hot ng:

S tip xc ca kh vi nc c thc hin do s va p ca dng kh

ln b mt cht lng v do s thay i hng t ngt

Kt qu ca s va p ni trn l hnh thnh nhng git nc mn

ng knh 300-400 m, lm tng qu trnh lng bi


Nguyn tc hot ng:

i vi thit b dng ny mc nc ng vai tr quan

trng. S thay i nh ca mc nc cng c th lm

gim hiu qu thu hi bi hoc lm tng tr lc ca thit

b.

Hiu qu ca thit b va p qun tnh n 99,5% i vi

ht c d 3m.


Cu to:

Dng in hnh ca loi thit b lc bi

theo nguyn l va p qun tnh t l

loi Rotoclon-N

Rotoclon-N

1.Ming vo ca kh;

2. Cnh hng dng;

3. Tm chn nc;

4. Ming dn kh sch thot ra;

5. Qut ht


c im:

+Thit b ny khng cn phng tin vn chuyn nc phun vo thit b, khng

cn vi phun. Ch cn mt mc nc n nh, khng cn bm p lc cao.

+ ng knh ca ht nc t 300-400m.

+ Vn tc kh vo thit b l 15 m/s. Vn tc dng kh ra khi qut kh ln.

+ Lng nc tiu hao cho qu trnh ny thng khng qu ln, thng 0,7

l/m3

+ Nng lng tiu th cho loi thit b ny nm trong khong 1,0 1,3 kWh cho

1000 m3/h lu lng kh cn x l.

Phm vi p dng:

+ Thit b lm vic c vi nng bi ban u rt cao.

+ Rotoclon N thng c s dng rng ri trong cng nghip luyn kim

lc bi thng thng v bi c tnh kt dnh cng nh cc loi bi d gy

chy n

f. Thit b ra kh vn tc cao ( thit b ra kh venturi)

lm sch kh khi bi kch thc 1-2 v nh hn,

ngi ta ng dng ch yu cc thit b ra kh vn tc

ln.

Nguyn l hot ng: Dng kh bi chuyn ng vi vn

tc 70 150 m/s p v nc thnh cc git cc nh.

xoy ri cao ca dng kh v vn tc tng i gia

bi v git lng ln thc y qu trnh lng bi trn cc

git lng.


Cu to v vn hnh

Thit b tch bi khi dng kh thi kiu Venturi c cu to gm:

ng tht eo Venturi 1 ni theo phng tip tuyn

vo thn hnh tr 2. Ti ch tht ca ng Venturi

c lp vi phun nc 3. Khi dng kh mang bi

c y vo ng Venturi vi vn tc ln,

ng nng ca dng kh ch tht ca ng

Venturi s ko theo nc v x nc

thnh nhng git mn. Bi trong dng kh s va

p qun tnh vo cc git nc v b ng li

trn b mt git nc. n lt mnh, nhng

git nc mang theo bi b dng kh chuyn ng

xon c trong thn hnh tr p vo thnh v chy

xung di ri theo ng x 4 ra ngoi, cn

kh sch thot ln trn qua ming ng 5

MT S THIT B RA KH VENTURI


Vn tc kh ti im phun nc c vn tc rt cao 70-150m/s,

Vn tc kh ti ng loa c gim xung cn 10-20m/s.

Lng nc phun vo thit b t 0,5-1,0 l/m3 kh

2.2.3 THIT B LC IN

Nguyn tc lc bi bng tnh in:

Tch in m cho ht bi, bi s mang in tch m, khi bi i qua b mt c

in tch dng, bi s b ht vo b mt ny, trung ha in v ri xung.

Thit b s dng dng in mt chiu vi in th cao (khong 50.000V).

Thng c 2 hnh thc lc bi tnh in: lc bi bng in kiu ng v lc

bi bng in kiu tm.

Thit b lc bi bng in kiu ng

c im:

+ Thit b s dng dng in mt chiu c U = 30 - 70 kV

+ Yu cu bi vo thit b phi kh.

+ Hiu sut lc bi cao: 95-99%.

+ Lc c tt c cc loi bi t kch thc ln n kch thc nh.

+ Gi thnh t, tiu tn mt lng in ln.

Phm vi p dng

Thit b ny ch c s dng nhng ni cn thu hi nhng loi bi qu c ga

tr hoc nhng ni yu cu cht lng mi trng cao

2.3 LA CHN THIT B X L BI

Bung lng bi

S dng cho bi th, kch thc >50m

Cn c s dng nh cp lc th trc cc lai thit

b lc tinh t tin

Cyclone

S dng cho bi th

Nng bi ban u cao

Khng i hi hiu qu lc cao

Nu mun t c hiu qu cao th nn s dng

xiclon t hoc xiclon chm


Thit b lc bi t

S dng khi cn lc sch bi mn vi hiu qu tng

i cao.

Kt hp gia lc bi v kh kh c hi trong phm vi

c th, nht l vi cc lai kh hi chy

Kt hp lm ngui kh thi

c bit m cao trong cc lai kh thi khi i ra khi

thit bi lc khng gy nh hng g ng k cho thit

b cng nh cc qu trnh cng ngh lin quan


Thit b lc ti vi

S dng khi cn t hiu qu lc cao hoc rt cao

Cn thu hi bi c gi tr trng thi kh

Lu lng kh thi cn lc khng qu ln

Nhit kh thi tng i thp

Thit b lc in

Khi cn lc bi tinh vi hiu qu lc bi cao

Lu lng kh thi cn lc ln

Cn thu hi bi c gi tr

2.4 CC YU T NH HNG N VIC LA CHN

PHNG PHP X L

Nhit v m ca kh i vo h thng lc bi v

nhng cht nhim khc i km theo

Cc c tnh l ha ca bi: vt liu bi, phn cp c

ht,

Nng ban u ca bi trong kh thi

Lu lng kh thi v s thay i ca lu lng

Mc lc yu cu v nng cho php ca bi cn

li trong kh thi sau lc

Phng php v chu k x bi, kh nng thu hi bi c

gi tr

2.4 CC YU T NH HNG N VIC LA CHN

PHNG PHP X L

Cc yu cu c bit i vi h thng ht bi

Thi gian lm vic, v tr t thit b

i vi thit b lc bui t ta cn phi lu n ngun

nc cung cp, nc thi c ln cn bn, m cao

ca kh thi

Cc iu kin vn hnh

2.3 X L TP CHT KH V HI C HI

Hng ngy, hng gi, nn cng nghip ( nht l cng nghip ha cht),

giao thng vn ti, trm nhit in, x vo bu kh quyn quanh ta

mt lng ln cc kh v hi thi v cng ln lm nhim bu kh

quyn

V d:

- X nghip luyn kim en: thi cc kh c cha bi, SO2 v kim loi mu

- Snh s, thu tinh, vt liu xy dng : Bi, COx , HF

- Luyn kim, l c : Bi, SO2 , COx , NOx ,

- Nha, cao su, cht do: Bi, mi hi, dung mi hu c, SO2

- Thuc tr su: Bi, mi hi, dung mi hu c, TBVTV

Ty thuc vo iu kin pht sinh, nng cht nhim, iu kin a hnh, trang thit b hin c la chn p dng cc phng php x l khc nhau.

2.3 X L TP CHT KH V HI C HI

Cc phng php x l:

Hp ph cc cht kh nhim bng cc vt liu rn;

Thiu t

Hp th cc cht kh c hi bng cht lng;

2.3.1 PHNG PHP HP PH

X l kh thi bng phng php hp ph l qu trnh x l da trn

s phn ly kh bi i lc ca mt s cht rn i vi mt s loi kh

c mt trong hn hp kh, trong qu trnh cc phn t cht kh

nhim trong kh thi b gi li trn b mt vt liu rn

Vt liu rn s dng trong qu trnh ny gi l cht hp ph.

Cht kh b gi li trong cht hp ph c gi l cht b hp ph

ng dng phng php hp ph :

-Kh m trong khng kh

- Kh mi trong kh thi

c bit qu trnh hp ph c p dng rt ph hp cho nhng trng

hp sau y:

- Cht kh nhim khng chy c hoc kh t chy;

- Cht kh cn kh l c gi tr v cn thu hi;

- Cht kh nhim c nng thp trong kh thi m cc qu trnh

kh kh khc khng p dng c.

C ch ca qu trnh hp ph

2.3.2 PHNG PHP HP PH

Hp ph vt l:

- Cc phn t kh b ht vo b mt cht hp ph nh lc lin kt gia cc

phn t ( lc Vander waals), cu trc ca kh sau khi b hp ph vn khng

thay i;

- L qu trnh thun nghch;

Hp ph ha hc:

-To thnh lin kt ha hc gia cht hp ph v cht b hp ph;

- Khng thun nghch;

VT LIU HP PH

Tnh cht

Vt liu dng lm cht hp ph l cc vt liu xp vi b mt bn

trong ln ( b mt t do ca cc l rng ln), chng c th l vt liu

t nhin hoc tng hp.

C kh nng hp ph cao;

Bn c hc

C kh nng hon nguyn d dng

Gi thnh r

Cc cht hp ph cng nghip c bn l than hot tnh, silicagen,

keo nhm (oxit nhm hot ha), zeolit.

VT LIU HP PH

Cc s liu k thut ca cc cht hp ph thng dng

Vt liu Khi

lng

n v

ng

(kg/m3)

ng khnh

l rng (m)

B mt l

rng

(m2/g)

ng dng

Than hot

tinh

360-600 (20-40).1010 500-1500 Hp ph km cc cht phn cc. N c dng lm v sinh v x l kh thi c

m khc nhau, hp ph hi cc cht hu c,

dung mi bay hi

Silicagel 400-900 (30-200).1010 200-600 Dng hp ph cc cht phn cc, cc hi v kh d ngng t, hi cc cht hu c

Alumogel 1000 90.1010 175 Hp ph cc hp cht hu c phn cc v sy kh

Zeolit 4.1010

c tnh hp ph cao i vi hi cc cht phn

cc, cc cht c mi lin kt i, ba trong

phn t, dng lm sch kh c cha lu

hunh, nito.

HON NGUYN CHT HP PH

Cn thit phi ti sinh ( hon nguyn) cht hp ph thu hi cu t

b hp ph v phc hi kh nng hp ph ca cht hp ph. Qu

trnh ti sinh c th c tin hnh bng nhng cch sau:

- Hon nguyn bng hi nc

- Ht cu t b hp ph bng cht hp ph khc mnh hn,

- Gim p sut ( bao gm to chn khng)

- Hon nguyn bng kh tr

THIT B HP PH

Thit b hp ph c hon nguyn chia thnh ba loi: c nh, di

ng v tng si. Cch phn chia ny da trn phng thc tip

xc gia pha kh v pha rn. Vic la chn phng n x l ph

thuc vo dng cht nhim v yu cu thu hi.

Yu cu ra khi thit k hoc la chn thit b hp ph l

+ Phi m bo thi gian chu k hp ph thch hp;

+ C x l s b i vi kh thi loi b mt s cht m m vt

liu hp ph khng hp thu c.

+ X l lm gim bt nng ban u ca cht cn kh trong kh thi

bo v lp vt liu hp ph khi b qu ti.

+ Phn phi dng kh i qua lp vt liu hp ph mt cch u n.

+ m bo kh nng thay th mi hay hon nguyn vt liu hp ph

sau khi t trng thi hp ph mt cch d dng.

CC QU TRNH HP PH

A. Hp ph hi cc dung mi bay hi

- Hin nay trn th gii c mt lng ln hi cc cht dung mi tn

tht ra mi trng gy tc hi v mi sinh v gy lng ph ln.

- thu hi chng, ngi ta thng dng phng php hp ph vi

cc cht hp ph thng dng nh than hot tnh, silicagel,

alumogel, zeolit, thy tinh xp

- c bit, than hot tnh l cht hp ph k nc nn rt hay c

dng: khi m tng i ca h hp kh di 50% th khng nh

hng n kh nng hp ph ca dung mi hu c.

- Vic hp ph hi cc dung mi c th xy ra trong cc lp vt liu

hp ph nm yn, tng si hay chuyn ng lin tc.

CC QU TRNH HP PH

B. Tch kh SO2

- S dng cc cht hp ph ha hc nh vi sng, vi ti v dolimit

dng ht bi.

- tng hot hp ph ha hc, gim qu trnh chuyn ha SO2

thnh SO3 th ngi ta thm mt s cht ph gia v c r tin nh

oxyclorit ng, oxytmagie, oxyt kim loi ca Al, Co, Cr, Fe

C. Tch Cl2 v HCl

- C th hp ph kh Cl2 bng cc loi ht lignin v lignin-sunfonat

canxi rn: l nhng ph thi ca cng nghip ch bin g, giy.

- hp ph kh HCl t kh thi cng nghip, c th dng FeClO;

CuCl hn hp vi MnO2, cc sunfat v phosphat ng , km,

cadmin. Nhng cht ny to phc vi phn t HCl. Ngoi ra c th

dng mt s vt liu nh zeolit

CC QU TRNH HP PH

D. Tch kh H2S v cc hp cht hu c c cha lu hunh

- tch kh H2S t kh thi c th dng hydroxit st, than hot tnh,

zeolit...

- Cc hp cht hu c c cha lu hunh nh CS2, tiofen C4H4S, R-SH(

mercaptan), R-S-R u l nhng cht gy nhim mi trng khi n

theo kh thi cng nghip x vo kh quyn. Phng php hp ph dng

than hot tnh, zeolit

E. Tch hi thy ngn

- Kh thi t ngnh cng nghip luyn kim mu, t hp cung cp nhit

nng, cng nghip ha cht thng c nhim hi thy ngn. Thng

thng ngi ta dng phng php vt l lm sch s b, sau dng

cc phng php ha hc lm sch tinh. Thng thng, than hot tnh

dng hp ph thy ngn phi qua mt s giai on s l s b bng

cc tc nhn sunfat hot, sunfit ha halogen

2.3.2 PHNG PHP HP TH

Hp th da trn c s ca qu trnh truyn khi, ngha l c s vn

chuyn t pha ny vo pha khc, l qu trnh ha tan cht kh trong cht

lng khi chng tip xc vi nhau.

Phn loi:

Hp th vt l: da trn s tng tc vt l thun ty; ngha l ch bao

gm s khuch tn, ha tan cc cht cn hp th vo trong lng cht lng

v s phn b ca chng gia cc phn t cht lng. V d nh s phn

b ca kh ho tan gia cc phn t cht lng: NH3/aceton, CO/benzen,

trimetylamin/du ho, s ho tan ca kh SO3/H2SO4.

Hp th ha hc: l mt qu trnh lun i km vi mt hay nhiu phn ng ha hc. Mt qu trnh hp th ho hc bao gi cng bao gm 2 giai

on: giai on khuch tn v giai on xy ra cc phn ng ha hc.

Phng php hp th cht nhim bng cht lng c s dng kh ph

bin trong x l kh thi Vit Nam, hay c p dng x l cc loi

kh nh SO2, CO2, H2S, NOx,Cht lng hp th c th l nc, axit,

baz

HP TH KH BNG CHT LNG

C ch:

Khuch tn cc phn t cht nhim th kh trong khi kh thi n b mt

ca cht lng hp th.

Thm nhp v ha tan cht kh vo b mt ca cht hp th.

Khuch tn cht kh ha tan trn b mt ngn cch vo su trong lng

khi cht lng hp th.

Qu trnh hp th ng mt vai tr quan trng trong sn xut ha hc, n c

ng dng :

- Thu hi cc cu t qu;

- Lm sch kh;

- Tch hn hp thnh cu t ring;

HP TH KH BNG CHT LNG(tt)

Cht hp th ( dung mi)

C kh nng hp th cao;

Khng bay hi;

Khng gy n mn thit b;

Gi thnh thp v d kim trong sn xut cng nghip;

nht b gim tr lc tng tc hp th;

C tnh chn lc cao theo quan h vi thnh phn cn c tch

ra. y l tnh cht ch yu ca dung mi;

C kh nng hon nguyn tt;

HP TH KH BNG CHT LNG(tt)

Trong k thut x l kh thi bng phng php hp th, nc l

loi cht hp th sn c, gi r v thun li nht. Tuy nhin,

nc ch hp th c mt s t loi kh c hi, hn na mc

hp th vt l ca nc cng b hn ch. Trong nhiu trng

hp ngi ta phi p dng phng php hp th ha hc bng

cc loi dung dch ha cht khc nhau ty theo cht c hi cn

kh

Mt s cht hp th x l cc kh nhim thng gp

THIT B HP TH

Thit b hp th c chc nng to ra b mt tip xc cng ln

cng tt gia hai pha kh v lng. C rt nhiu dng kiu khc

nhau ca thit b hp th, nhng c th phn chia thnh ba loi

chnh sau y:

Bung phun, thp phun: trong cht lng c phun thnh

git nh trong th tch rng ca thit b v cho dng kh i qua.

Thit b hp th kiu si bt (thp mm): kh i qua tm c l

bn trn c cha lp nc mng.

Thit b hp th c lp m bng vt liu rng( thp m):

Cht lng c ti trn lp m rng v chy xung di to

thnh b mt t ca lp m dng kh tip xc i qua.

A. THP PHUN, BUNG PHUN

Nguyn tc lm vic:

Trong thp phun, cht lng c phun thnh sng t pha trn xung, kh

thng i t di ln nhm lm tng din tch tip xc v nng thc

t ca cht cn hp th trong pha kh gim dn theo chiu t di i ln v

nng cht b hp th trong pha lng c tng dn theo chiu t trn i

xung.

c im

Yu cu tc dng kh khng c qu ln ( phi nh hn 1m/s)

trnh hin tng cht lng b cun theo kh ra ngoi;

Thit b hp th thp phun c u im l n gin, chi ph u t thp, lc

cn thy ng nh v c th s dng i vi kh thi c nhim bn cao;

cht lng dng hp th c th quay vng cho ti khi hp th no mi

thi, cho nn tit kim c cht hp th;

Tuy nhin, nhc im ca thit b thng rng l kh thng phn b

khng u trong ton b thp dn nn lm gim hiu sut x l

A.THP PHUN, BUNG PHUN

B.THP M

Cu to

c dng ph bin nht. Trong thp, ngi ta thng cc vt liu m

nh c, snh s, l so kim loi. vn than cc... lm tng din tch tip

xc hai pha.

Nguyn tc lm vic

Cht lng c ti trn b mt lp vt liu rng v chy t trn xung di

to ra b mt t ca lp vt liu m. Kh c dn t di ln tip xc

vi cc b mt t , cc cht nhim b hp th li, kh sch c dn ra

ngoi.

u im:

Tr lc thp;

Vn hnh n gin;

Gi thnh c th chp nhn c;

Nhc im:

Kh khn trong vic ra cc vt liu m

D gy tc nghn

B.THP M

B. Thp m

Tnh cht vt liu m:

Yu cu chung ca cc loi vt liu m l phi c din tch b

mt ring ln; ngoi ra, rng( hay th tch t do) ln

gim tr lc cho pha kh. Vt liu ch to vt liu m phi c

khi lng ring nh v bn ha hc.

Ton b vt liu m c t trn mt b phn vt m

cng l b phn phn phi kh. Cht lng c phn phi

nh thp qua b phn phn phi lng sao cho cht lng phi

thm t ton b vt liu m.

Vt liu m c y trong thp theo mt trong hai

phng php: Xp ngu nhin hoc xp theo th t.

B.THP M

C. Thp mm (ging thp si bt trong x l bi)

Thng c s dng trong trng hp ti lng cao, p sut kh phi ln.

Nguyn lm vic ca thit b l khi thi cn lm sch i vo khoang trng bn di ( dng kh i t di ln) ca thit b hp th gm nhiu mm c c l. Khi thi theo cc l trn mm sc qua lp dung dch hp th, lm si bt. Kh cn x l s bm vo b mt cc bt kh-lng ny v, do , dng khi thi c x l.

C. Thp mm (ging thp si bt trong x l bi)

Hp th kiu ny c nhc im ln nht l lun c lp bt

chim th tch kh ln trong thit b. Vic chuyn ng ca

cht lng gp phi tr lc ln. Cc nh thit k c nhiu

cng trnh lm gim bt nhng im trn c th s dng

kiu hp th ny trong cng nghip v n c h s chuyn khi

rt cao.

Chiu cao lp cht lng tng s lm tng kh nng hp th

song ng thi cng tng tr lc ca thit b. V vy, thng

thng ngi ta khng tng lp cht lng qu 50mm

Thn thp v mm c lm bng loi vt liu ph thuc vo

kh nng n mn ca mi trng lm vic. Thn thp thng

c hnh tr trn, ch to thnh tng on ghp vi nhau bng

mt bch. Mm c gn c nh vo thp.

C.THP MM

C. Thp mm

Ty theo lu lng ca hai pha lng kh m c ba ch thy ng:

- Khi vn tc kh qu nh th pha kh i qua pha lng dng tng bt ring

bit, pha lng c th chy r qua l trn mm;

- Khi tng vn tc kh ln th kh i qua lng bng nhng tia bt lin tc, cht

lng khng cn ch r qua l trn mm. ch ny, thp hot ng n

nh.

- Khi tng vn tc kh ln na, kh v lng trn mm s to nn mt hn hp

lng bt xo trn mnh trn mm. iu kin ny, mm hot ng vi hiu

sut cao nht. Nu tip tc tng vn tc kh ln na s xy ra hin tng li

cun cht lng trn mm.

C. Thp mm

So snh u v nhc im ca cc loi thp

So snh Thp phun Thp m Thp mm xuyn l Thp mm chp

u

im

n gin;

Chi ph thp;

Tr lc thp;

Vn tc kh thp

n gin;

Tr lc thp;

Hiu sut tng i cao;

Hot ng kh n nh;

Lm vic vi cht lng

bn;

Hiu sut cao;

Hot ng n

nh;

Nhc

im

Hiu sut thp; Hiu sut thp;

n nh km;

Thit b nng;

Tr lc kh cao;

Yu cu lp t kht

khelp a tht phng;

Cu to phc tp;

Tr lc ln;

Khng lm vic

vi cht lng bn

2.3.3 PHNG PHP NHIT-THIU T

Bn cht ca phng php t chy trc tip l oxy ha cc cu t

c hi bng oxy nhit cao (450-12000C). Phng php ny

c ng dng x l kh thi cc cht c d oxy ha v nhng

hn hp c mi tanh hi.

u im:

- Phn hy hon ton cc cht nhim chy c khi thit b thiu t

c thit k v vn hnh ng quy cch;

- Hiu qu x l cao i vi nhng cht nhim c bit m cc bin

php x l khc khng c hiu qu hoc hiu qu thp;

- C kh nng thu hi v tn dng c nhit thi ra trong qu trnh

thiu t;

Nhc im:

- Chi ph u t thit b v vn hnh tng i ln;

- Cn cung cp thm nhin liu v xc tc m bo nhit cn

thit cho qu trnh oxi ha cc cht nhim cn x l.

- Lm phc tp thm vn gy nhim khng kh khi trong kh thi

u vo c cha cc hp cht ca clorin, nito, lu hunh

thit k c cc thit b thiu t, cn mt s lu sau:

-Thnh phn ha hc ca cc cht gy nhim, nng cn x l, nhit ban du ca kh thi i vo thit b thiu t v mc pht thi cho php ca cc cht gy nhim;

- Nhit chy: phi lun gi nhit chy ( nhit gia nhit cho qu trnh chy) phi ln hn nhit bc chy, b vo lng nhit mt mt do tn tht nhit ra xung quanh;

- Thi gian chy: Tng cao ng khi, tng thi gian chy s hn ch c lng khi bc ra.

- xo trn :nhm to cho hn hp oxy v vt cht chy c ng u trong sut thi gian chy. C th dng vch ngn hoc vi phun to ra khuy trn cn thit.

- Oxy: oxy l yu t cn cho qu trnh chy xy ra. Nhng sn phm cui cng ca qu trnh chy ph thuc vo vic cung cp oxy.

2.3.3 PHNG PHP NHIT-THIU T

Cc phng php thiu t hi kh thi nhim

V mt bin php thc hin, qu trnh thiu t cht nhim c

th c phn chia ra thnh ba loi chnh:

- Thiu t bng ngn la trc tip trong khng kh;

- Thiu t c bung t;

- Thiu t c xc tc;

A. THIU T BNG NGN LA TRC TIP

Thit b t chy trc tip l thit b m khng kh v tt c cc kh thi c kh nng chy

bc t. Qu trnh t hon ton phi din ra ngay, mc d khng c bung t. Phng

php ny thng p dng cho vic x l kh thi nhim c cha Hydrocacbon, hydro,

amoniac, hydroxyanua hoc mt s loi cht khc.

Cu to u t ca h thng thiu t bng ngn la trc tip

1- ng dn kh thi; 2 vng khng ch vn tc kh thi; 3- ng gp phn phi hi nc; 4- cc im phun hi; 5- b phn mi la; 6- ng cp ga mi; 7 - ng cp hi nc

B. BUNG T

Tri ngc vi s t chy trc tip, trong qu trnh thiu nhit,

kh chy i qua hoc c di chuyn quanh m t n bung

lu. Ti y, qu trnh oxy ha (chy) xy ra hon ton. Thiu

t c bung t c p dng rt rng ri i vi cc loi kh

thi c cha cht nhim dng kh, hi hoc sol.

Bung t kh thi hnh tr ng

vi ng cp kh thi theo phng tip tuyn

1- ng dn kh thi;

2 ng cp nhin liu;

3- Ngn p lc;

4- Vi t;

5- v thp c p VL chu la;

6- ng khi thi kh sch vo kh quyn

B. BUNG T

S cu to bung t c hm nng trc kh thi nh sau:

1.Kh thi i vo thit b thiu t; 2. B mt trao i nhit sy nng kh thi;

3. Nhin liu; 4. Vi t; 5. Kh sch ra.

Thit lm vic ca bung t v mt s cht nhim thng gp

C.THIU T C XC TC

Qu trnh oxy ha xc tc rt ging qu trnh thiu nhit. im khc

nhau c bn l sau khi i qua vng la (vng chy) kh c a

vo tng xc tc, y mnh s oxy ha nhit thp hn nhit

oxy ha bnh thng.

Nhng cht xc tc c s dng l cc kim loi dng ht nh Platium,

Paladium hoc hp kim ca chng.

S cu to bung t c xc tc

C.THIU T C XC TC Nhit lm vic ca bung thiu t c xc tc

2.4 MT S H THNG X L KH THI N GIN

C P DNG TRONG THC T

X l kh thi l nu c kim loi

Nguyn liu u vo ca ngnh nu c kim loi bao gm ch t bnh acquy ph

thi, nhm, ng, gang t tn, v lon bia, nc ngt, v thit bNhin liu c

s dng c kim loi l than ci, than , du DO, du nht ph thi

Kh thi t l nu c kim loi cha bi, SO2, NO2, CO, cc oxit kim loi

u tin, kh thi c cho vo xyclon tch bi, nh lc ly tm. Sau , kh thi

c a qua thp hp th x l cc kh axit, ng thi c tc dng lc ra bi

mn.

Trong thp hp th, kh thi v dung dch hp th tip xc ngc dng. y, cc

kh axit s ha tan vo dung dch kim, phn ng vi ha cht trong v nh ,

tch ra khi kh thi. Dung dch sau khi hp th c dn vo b cha, tun hon

v b sung kim theo gi tr p H ca nc

X l kh thi l t rc y t

Rc y t l thuc nhm cht thi nguy hi, cn p dng phng php thiu t

x l chng. Qu trnh thiu t s sinh ra nhiu kh c hi bao gm bi, kh HCl,

SOx, NOx, VOC

Thuyt minh quy trnh cng ngh x l kh thi l t y t theo s di

CHNG III NHNG VN V CHT THI RN

3.1 i cng v cht thi rn

- Cht thi rn (CTR) (Solid wastes): bao gm tt c cc cht thi

dng rn, pht sinh do cc hot ng ca con ngi v sinh vt,

c thi b khi chng khng cn hu ch hay khi con ngi

khng mun s dng na

- CTR bao gm tt c cc cht rn hn hp thi ra t cng ng dn

c th cng nh cc CTR c th t cc ngnh sn xut nng

nghip, cng nghip, khai khong.

- Hin nay ngi ta quan tm c bit n CTR th, bi s tch

ly ca CTR ny c kh nng nh hng ln n mi trng sng

ca con ngi

3.1.1.Phn loi CTR

Cc ngun pht sinh:

- Khu dn c (h gia nh, chung c)

- Cc trung tm thng mi (ch, siu th,)

- Cc cng s (c quan, trng hc,)

- Cc dch v th (bn xe, sn bay, nh ga, khch sn, nha hng)

- Cc hot ng cng nghip

- Cc hot ng nng nghip

- Cc hot ng xy dng (nh ca, cu ng,)

- Cc c s y t (bnh vin, phong khm,)

- Cc h thng x l nc thi v thot nc th.

Theo tnh cht ha hc:

Ho Hc

Hu c

D phn hy

Kh phn hy

V C

3.1.1. Phn loi CTR

Theo mc nguy hi:

cht thi nguy hi: L cht thi bao gm cc loi ho cht d gy phn

ng, c hi, cc cht d chy, n hoc cc cht phng x, cht thi

nhim khun, lay lan c nguy c e do sc kho con ngi,

ng vt v thc vt.

cht thi khng nguy hi : L loi cht thi khng cha cht hoc hp

cht c mt trong s c tnh gy nguy hi trc tip n con ngi.

Theo kh nng chy c v khng chy c

Theo kh nng ti ch v thu hi ph liu

Mc pht sinh CTR ty thuc: mc sng, tp qun x hi, mc ti ch,.. khc nhau cc nc, cc thi.

Pht sinh MSW mt s quc gia khc nhau

Pht sinh MSW Vit Nam theo loi th

Ngun: Cc bo v Mi trng, 2007

Nc M

(2000)

Trung Quc

(2002)

n

(2002)

Thi Lan

(2002)

Vit Nam

(2003)

Mc pht sinh,

kg/ngi/ngy

2,0 0,63 0,45 1,36 0,7

Loi th c bit Loi I Loi II Loi III Loi IV

Mc pht sinh,

kg/ngi/ngy

0,96 0,84 0,72 0,73 0,65

3.1.2 Thnh phn, c im CTR

Thnh phn l, ha hc ca cht thi rn th rt khc nhau ty

thuc vo tng a phng, vo cc ma kh hu, cc iu kin

kinh t v nhiu yu t khc

Thnh phn in hnh ca cht thi rn th(%)

3.1.3 S lc v qun l CTR

Qun l cht thi rn l vn then cht ca vic m bo mi trng sng ca

con ngi m cc th phi c k hoch tng th qun l cht thi rn thch hp

mi c th x l kp thi v c hiu qu.

Nhim v ca cc c quan chc nng trong h thng qun l cht thi rn mt

s th ln Vit Nam:

B khoa hc cng ngh v mi trng chu trch nhim vch chin lc ci thin

mi trng chung cho c nc, t vn cho nh nc trong vic xut lut l

chnh sch qun l mi trng quc gia.

B xy dng hng dn chin lc qun l v xy dng th, qun l cht thi.

y ban Nhn dn thnh ph ch o y ban nhn dn cc qun, huyn, S Khoa

hc Cng ngh v Mi trng v S Giao thng Cng chnh thc hin nhim v

bo v mi trng th, chp hnh nghim chnh chin lc chung v lut php

v bo v mi trng ca Nh nc thng qua vic xy dng cc quy tc, quy

ch c th trong vic bo v mi trng ca thnh ph.

Cng ty Mi trng th l c quan trc tip m nhn nhim v x l cht thi

rn, bo v v sinh mi trng thnh ph theo chc trch c S Giao Thng

Cng Chnh thnh ph giao.


Mc ch ca qun l CTR

- Bo v sc khe cng ng

- Bo v mi trng

- S dng ti a vt liu, tit kim ti nguyn v nng lng

- Ti ch v s dng ti a rc hu c

- Gim thiu cht thi rn

nh lng ca cht thi rn n mi trng

- nh hng n mi trng nc

- nh hng n mi trng khng kh

- nh hng n mi trng t

- nh hng n cnh quan v sc khe con ngi

3.2 Cc phng php x l cht thi rn

a. Mc ch ca vic x l cht thi rn

X l cht thi rn l giai on cui cng ca cng tc qun l

cht thi rn, khng nhng lm mt tc hi ca chng m cn

l vn thu hi ti nguyn v cc sn phm, vt liu c ch

nhm phc v cuc sng con ngi.

- Thu hi ti nguyn: sn phm, vt liu nhm tit kim ti

nguyn thin nhin

- Nng cao gi tr ca cht thi rn t cc thnh phn c th

ti s dng, ti ch to ra cc sn phm mi phc v i

sng con ngi

- X l thi b nhm gii quyt yu cu bo v mi trng:

gim ti mc ti a hoc boi b nhng cht c hi ngn

chn nguy c gy nhim mi trng

3.2 Cc phng php x l cht thi rn

b. Phn loi cc phng php x l CTR

Vi nhng tin b ca khoa hc cng ngh, hin nay c nhiu phng php x

l CTR ang c s dng, ph bin nht l cc phng php sau:

X l s b CTR ( bm, cht, nghin, sy, tch phn chia cc hp phn

CTR);

Nn, p kin CTR;

Phng php sinh hc;

Phng php thiu t;

Phng php chn lp;

Vic la chn phng php x l CTR ph thuc vo:

- c im, thnh phn v tnh cht ca cht thi rn;

- Lng CTR pht sinh;

- Gi tr kinh t hay gi tr s dng cc loi vt liu c trong cht thi;

- Cc cng ngh hin c trong nc v trn th gii;

- Kh nng kinh t, iu kin ti chnh, t ai v iu kin c th ca a

phng;

Tuy nhin, trong bt k trng hp no cng phi m bo theo nguyn tc:

- Trnh thi b;

- Gim thiu rc thi;

- Ti s dng;

- Ti ch;

- Ti to nng lng;

- X l;

- Thi b an ton

Cc qu trnh chuyn ha s dng trong qun l CTR

Qu trnh Phng php thc hin S chuyn ha hoc cc sn phm chuyn ha c

bn

L hc:

Phn loi

Gim th tch

Gim kch thc

Th cng, c gii

Nn, p

Ct, xay, nghin

Cc thnh phn ring r c

trong CTRSH

Gim th tch cht thi

Gim kch thc cht thi

Ha hc:

t

Nhit phn

Oxy ha

Chng ct phn on

CO2, SO2, tro- cc sn

phm khng chy

Dng kh cha nhiu cht

kh khc nhau, hc n hoc

du, than

Sinh hc:

Sn xut phn compost

Phn hy k kh

Bin i sinh hc hiu kh

Bin i sinh hc k kh

Phn compost

CH4, CO2,bn

3.3 Thu gom cht thi rn

Thu gom cht thi rn l qu trnh thu nht rc thi t cc nh

dn, cc cng s hay t nhng im thu gom, cht chung ln

xe v ch n a im x l, chuyn tip trung chuyn hay

chn lp.

Dch v thu gom cht thi thng c th chia thnh cc dch

v s cp v th cp.

3.3 Thu gom cht thi rn

Thu gom cht thi rn t trong nh (thu gom s cp) l cch m

theo rc thi c thu gom t ngun pht sinh ra n (nh hay nhng

c s thng mi) v ch n cc bi cha chung, cc a im hoc bi

chuyn tip.

Thng th cc h thng thu gom s cp cc nc ang pht trin bao gm

nhng xe ch rc nh, xe hai bnh ko bng tay thu gom rc v ch

n cc bi cha chung hay nhng im chuyn tip.

Do vy, thu gom ban u s c cn n trong mi h thng qun l thu gom

v vn chuyn.

Thu gom tp trung (hay cn gi l thu gom th cp) bao hm khng ch

vic thu gom nht cc cht thi rn t nhng ngun khc nhau m cn c vic

chuyn ch cc cht thi ti a im tiu hy.

Nh vy thu gom th cp l cch thu gom cc loi cht thi rn t cc im

thu gom chung (im cu rc) trc khi vn chuyn chng theo tng phn

hoc c tuyn thu gom n mt trm trung chuyn, mt c s x l hay bi

chn lp bng cc loi phng tin chuyn dng c ng c.

3.4 H thng trung chuyn v vn chuyn

Trm trung chuyn c chc nng l chuyn CTR t cc xe thu

gom v cc xe vn chuyn nh sang cc phng tin ln hn.

S cn thit ca hot ng trung chuyn

Khong cch vn chuyn kh xa

Trm x l hay bi t xa trc l giao thng

Trm trung chuyn kt hp vi trm thu hi vt liu

Trm trung chuyn ti bi chn lp hp v sinh

Trm trung chuyn khi thay i phng thc vn chuyn

H thng trung chuyn v vn chuyn

Phng tin v phng php vn chuyn

Phng tin vn chuyn : xe ti , xe la, tu thy l nhng phng tin ch

yu c s dng trong vn chuyn CTR , bn cch cn s dng cc h thng

kh nn v h thng thy lc.

Phng php vn chuyn:

+ Vn chuyn bng ng b

+ Vn chuyn bng ng st

+ Vn chuyn bng ng thy

+ Vn chuyn bng kh nn, p lc nc bay hay cc h thng khc

3.2.1 Phng php c hc

* Mc ch:

- Gim kch thc v th tch CTR, dn n gim chi ph vn chuyn, x l.

- Thu hi cc loi vt liu c gi tr kinh t.

- To iu kin thun li cho cc qu trnh x l tip theo

3.2.1 Phng php c hc

* Bn cht ca phng php c hc:

- p dng cc lc c hc thay i kch thc, th tch, m v cc tnh

cht vt l khc ca cht thi. Phng php c hc nh phn loi, nn, p,

nghin, ct, bm

* Phm vi p dng:

p dng x l s b cht thi rn (ngay ti ngun pht sinh) trc

khi em i x l cc cng on tip theo.

3.2.1 Phng php c hc

u im:

n gin

C kh nng c gii ha v t ng ha.

Cc thnh phn khc nhau ca cht thi s c tch loi nn to iu kin thun li, d dng cho cc cng on x l tip theo ng thi c th thu hi v ti ch c cc vt liu c gi tr.

Nhc im:

Cha x l trit c cht thi, nn yu cu phi c cc bc x l tip theo.

Rt d gy nhim mi trng.

3.2.1 Phng php c hc

Cc thit b c kh c th s dng cho mc ch phn loi rc bao gm:

- Qut gi: Phng php ny c s dng phn loi cc cht thi rn kh, c trng lng khc nhau. Qut gi hot ng to lung kh, cun theo cc vt nh nh giy, ti nilon, nh tch c cc thnh phn ny ra khi cht thi hn hp.

- Sng: Sng c dng phn loi cc thnh phn cht thi c kch thc khc nhau.

- Phn loi bng t: Thit b phn loi bng t c s dng thu hi st vn t cht thi rn.

3.2.2 Phng php nhit

Khai Nim: L qu trnh s dng nhit chuyn ha cht thi t dng rn sang dng lng, khi va tro ng thi gii phng nng lng di dng nhit.

Mc ch: X l trit cht thi rn, thng dng x l cht thi nguy hi, y t.

u im:

Th tch v khi lng CTR gim ti mc thp nht so vi ban u;

Tn dng c nng lng nhit ca qu trnh

L thnh phn quan trng trong chng trnh qun ly tng hp CTR

CTR c th x ly ti ch m khng phi vn chuyn i xa

Hiu qu x ly cao

Nhc im

Vn u t ban u cao

Vic thit k, vn hnh phc tp i hi nng lc ky thut va tay ngh cao

Nhng tim nng tc ng n con ngi va mi trng c th xy ra

3.2.2 Phng php nhit

Phn loi l t v cc qu trnh t CTR

Theo phng php thiu t: l t n vng, l t a vng;

Theo v tr b tr l t: t tp trung hay phn tn;

Theo ch vn hnh: l quay v l tnh;

Theo c im ca ngun nguyn liu t: CTR hn hp, CTR

c x l s b;

Theo ch cung cp khng kh

3.2.2 Phng php nhit

Theo ch cung cp khng kh, ngi ta chia ra:

Qu trnh t ha hc: qu trnh t v d kh ( t hn hp

CTR; t thu hi ti nguyn sn phm, nng lng; t

tng si

Qu trnh kh ha: thiu kh ( l ng, l quay, t tng si)

Qu trnh nhit phn: khng c khng kh ( t tng si)

Nguyn Tc 3T

Thi gian

Nhit

xao trn

3.2.3 Phng php sinh hc

Mc ch:

X l CTR, gim tc ng n mi trng;

Tn thu c cc sn phm lm phn bn;

Gim lng cht thi em i chn lp;

Bn cht ca phng php sinh hc:l qu trnh n nh/

chuyn ha sinh hc cc cht hu c to thnh cc cht

mn hu c c kh nng lm tng ph nhiu ca t.

Cc bin php k thut:

phn hiu kh;

Phn hy cht thi ln men k kh;

Metan ha trong cc b thu hi kh sinh hc

3.2.3 Phng php sinh hc

u im

n nh c cht thi;

Lm mt hot tnh ca vi sinh vt gy bnh;

Thu hi c cht dinh dng v ci to t;

Nhc im:

Qu trnh phn hy sinh hc to mi hi, mt m quan,..

Sn phm ca cc qu trnh vn khng c s dng rng

ri trong nng nghip.

Phm vi p dng

i vi cht thi c th phn hy sinh hc c

X l v chuyn ha thnh phn hu c c trong cht thi to

ra cht mn phc v cho cy trng

3.2.4 Phng php chn lp Mc ch:

chn lp l phng php ph bin x l sau cng i vi CTR

Bi chn lp CTR hp v sinh l bi dng chn lp an ton, tin cy v lu di cc loi cht thi rn khng cn ti ch, thu hi, cc phn cn li d tha sau ti ch CTR v tro l t

Bi chn lp CTR bao gm 1 hay nhiu rc, mi chn lp cn c thit k c bit, c h thng chng thm k thut thnh v y bi, h thng thu gom nc rc v kh rc, k thut chn lp v m nn,

Bn cht ca phng php chn lp:

Thc cht ca chn lp l qu trnh sinh hc CTR th trong iu kin bn hiu kh hay k kh

Cc phn ng sinh hc quan trng nht xy ra trong bi chn lp l cc phn ng bin i cc cht hu c thnh kh bi rc v cc cht lng.

3.2.4 Phng php chn lp

u im

X l khi lng rt ln cht thi.

Chi ph u t v chi ph x l nh.

Nhc im:

Chim nhiu din tch.

Gy nhim khu vc x l.

Thi gian phn hy chm.

Hin nay trn th gii thng s dng cc loi bi chn lp

sau

Loi 1: Bi chn lp rc thi th

Loi 2: Bi chn lp cht thi nguy hi

Loi 3: Bi chn lp cht thi xc nh

3.2.4 Phng php chn lp

La chn v tr bi chn lp

Bi chn lp phi ph hp vi cnh quan mi trng.

Phi tnh n hng gi thi.

Khng t vng ngp lt, c mch nc ngm.

Giao thng n khu vc chn lp phi thun li.

Phi c khong cch thch hp vi vng dn c.

La chn a cht khu vc bi chn lp

Nn chn vng t c thm thu thp

CHNG IV- X L NC THI

4.1 NGUN GC, THNH PHN V TNH CHT CA NC THI

4.1.1 nh ngha, cc ngun pht sinh nc thi

Nc thi (NT): l nc sinh ra t qu trnh sinh hot, sn xut hoc chy qua vng t nhim.

Ph thuc vo iu kin hnh thnh, nc thi c chia thnh:

Nc thi sinh hot

Nc ma

Nc thi cng nghip

A. Nc thi sinh hot ( Domestic wastewater)

Nc thi sinh hot l nc x b sau khi s dng cho cc mc ch sinh hot ca cng ng: tm, git gi, ty ra, v sinh c nhn,

Nc thi sinh hot thi ra t cc cn h, c quan, trng hc, bnh vin, ch, cc cng trnh cng cng khc v nc thi v sinh ca cng nhn trong XNCN;

Khi lng nc thi sinh hot ca mt cng ng dn c ph thuc vo:

- Qui m dn s

- Tiu chun cp nc

- Kh nng v c im ca h thng thot nc

A. Nc thi sinh hot ( Domestic wastewater)

c tnh chung ca NTSH: c hm lng cc cht hu c khng bn sinh hc cao (BOD5/COD) ( nh cacbonhydrat, protein, m); cc cht dinh dng ( nito, phospho), cc vi trng gy bnh ( E.coli, coliform), cht rn ( SS) v mi.

Mc nhim ca nc thi sinh hot ph thuc vo:

- Lu lng nc thi;

- Ti trng cht bn tnh theo u ngi;

Ti trong cht bn tnh theo u ngi ph thuc vo:

- Mc sng, iu kin sng v tp qun sng;

- iu kin kh hu;

- Hot ng cng nghip;

B. Nc thi cng nghip ( Industrial wastewater)

Nc thi x ra t cc c s sn xut cng nghip sau khi s dng cho cc nhu cu sinh hot v s dng cho cc cng on sn xut;

Ti cc c s sn xut cng nghip, nc thi thng bao gm ba loi c thnh phn v tnh cht tng i khc bit nhau, l:

- Nc ma;

- Nc thi sinh hot;

- Nc thi sn xut;

B. Nc thi cng nghip ( Industrial wastewater)

Nc ma:

- c xem l nc thi qui c sch;

- Tuy nhin trong mt s trng hp c th b nhim bn cc mc khc nhau ( nc ma chy qua cc kho bi xng du, ha cht), cn phi thu gom v x l;

Nc thi sinh hot: nc thi do sinh hot ca cng nhn trong XNCN, NT t canteen;

Nc thi sn xut: chia lm 2 loi:

- Nc thi qui c sch: gii nhit my mc thit b, lm ngui mt s sn phm khng ha tan ( nha, cao su,, da);

- Nc thi nhim bn: nhn chung rt a dng ty theo c im ca tng ngnh ngh sn xut v ch v sinh cng nghip.

C. Nc ma

V c bn th nc ma l mt ngun nc thi sch;

Tuy nhin trong mt s trng hp, nc ma khi vo h thng thu gom thng mang theo mt s cht bn nh du m, cn v c hu c

Mc nhim bn ca nc ma thng ch xut hin nhng trn ma u ma v trong thi gian u ca mi cn ma;

Nc ma chy trn t cc ng rung mang theo cht rn, thuc st trng, phn bn

4.1.2 H thng qun l nc thi ( wastewater management system)

Mt h thng qun l nc thi bao gm:

Ngun thi

Mng li thot nc thi: Thu gom v vn chuyn nc thi. ( ng dn v trm bm)

Trm x l nc thi

Cng trnh x v ngun tip nhn

H thng thot nc( Sewerage) H thng thot nc chung ( combined system): nc ma

v nc thi c vn chuyn trong cng mt mng li ti TXL

H thng thot nc ring ( Separate system): tng loi nc thi ring bit c thu gom v vn chuyn theo mng li ring bit.

H THNG THOT NC RING ( SEPARATE SYSTEM)

H THNG THOT NC X NGHIP CNG NGHIP

Mi XNCN u c h thng thot nc, bao gm:

Mng li thot nc;

Trm x l cc b ( hoc theo cm) lm nhim v:

- Dn nc thi ra khi phm vi XNCN;

- X l NT cng nghip t yu cu, tiu chun mi trng ng thi c th thu hi li cc cht ( thnh phn) c gi tr.

S cp thot nc trong XNCN

S THOT NC CC B TRONG XNCN

4.1.3 THNH PHN V TNH CHT NC THI

4.1.3.1 Cc ch tiu cht lng nc

- Cc ch tiu l hc: nhit , mu, mi v, c, cn l lng (SS), tng cht rn (TS), nht, tnh phng x

- Cc ch tiu ha hc: pH, axit, kim, cng, clorua, sunphat, st, mangan, clor d, oxy hoa tan (DO), nhu cu oxy ha hc ( COD), nhu cu oxy sinh ha (BOD), nito v cc hp cht cha nito, cht bo v du m, cht c hot tnh b mt, kim loi nng, thuc dit c, thuc tr su, coliform phn

A. Hm lng cht rn

Tng cht rn ( TS): (mg/l)

- Tng ca tt c cc cht rn c ngun gc v c v hu c c trong NT trng thi l lng v ha tan;

- L phn cn li sau khi cho NT bay hi hon ton 105 C- cn kh.

Cht rn l lng(SS): (mg/l)

- Ly mu NT lc qua giy lc tiu chun;

- Phn cn trn giy c sy kh 105 C, cn li s tnh c lng cht rn l lng;

Cht rn ha tan ( DS):

- DS= TS-SS

B. Hm lng oxi ha tan (DO)

- L lng oxy ha tan trong nc cn thit cho s h hp ca c sinh vt nc, thng c to ra do s ha tan t kh quyn hoc do s quang hp ca to.

- S hin din ca oxy ha tan trong nc chng t cht lng nc tt, v ngc li s thiu vng oxy ho tan l du hiu cho thy ngun nc b nhim

- Trong iu kin nhit v p sut bnh thng: lng oxi ha tan trong nc 8-10 mg/l, dao ng mng ph thuc vo nhit , s phn hy ha cht, s quang hp ca to

S BIN THIN DO THEO DNG CHY

C. Nhu cu oxi sinh ha BOD

L lng oxi cn thit vi sinh vt oxi ha cc cht hu c

d phn hy c trong NT trong mt khong thi gian xc

nh.

- Nhu cu oxy sinh ha l ch tiu rt quan trng v tin dng

ch mc nhim bn ca nc thi bng cc cht hu

c.

- BOD5: Oxy ho ht cht hu c trong nc thng

phi mt 20 ngy 20oC. n gin ngi ta ch ly ch

s BOD sau khi Oxy ho 5 ngy, k hiu BOD5. Sau 5

ngy c khong 80% cht hu c b oxy ho

- BOD20

D. Nhu cu oxy ha hc (COD)

L lng oxi cn thit oxi ha hon ton hp cht

hu c v mt phn nh cc cht v c d b oxy

ha c trong nc thi.

- Ch tiu nhu cu oxy sinh ha BOD khng

phn nh kh nng oxy ha cc cht hu c kh b

oxy ha v cc cht v c c th b oxy ha c

trong nc thi, nht l nc thi cng nghip. V

vy, cn phi xc nh nhu cu oxy ha hc COD

oxy ha hon ton cc cht bn c trong nc

thi.

.

E. Cc cht dinh dng N,P nguyn t cn thit cho s pht trin ca cc sinh

vt nguyn sinh v thc vt; S hin din ca cc hp cht cha nito dng ny

hay dng khc trong nc s l cht ch th nhn bit trng thi nhim bn ca ngun nc:

- Khi ch c mt NH4+ m khng c nitrit chng t ngun nc va mi nhim;

- Khi c s hin din ng thi NH4+ v nitrit thi gian nhim giai on u chm dt v chuyn qua giai on trung gian;

- Khi khng cn NH4+ m c mt nitrit v nitrat c ngha l s nhim din ra t lu v trong thi gian ng thi cng xy ra qu trnh t lm sch ca ngun nc

F. Ch s vi sinh vt

- Nhm Coliform: E. coli

- Nhm Streptococci;

- Nhm Clostridia kh sunfit

G. Cc kim loi nng: Ch, thy ngn, asen, cadmi, crom, selen, niken l cc tc nhn gy c hi ti nguyn thy sinh v sc khe con ngi ngay nng thp.

H. Mu: nc t nhin c th c mu v cc l do:

- Cc cht hu c trong cy c b phn r;

- Nc c st v mangan dng ko hoc dng ha tan;

- Nc c cht thi cng nghip ( crom, tannin, lingin..).

Mu thc ca nc l mu to ra do cc cht ha tan hoc dng ht keo. Trong thc t, ngi ta ch xc nh mu thc ca nc, ngha l sau khi lc b cc cht khng tan.

I. Mi: Nc c mi l do cc nguyn nhn: - C cht hu c t cng rnh khu dn c , x nghip

ch bin thc phm;

- C nc thi cng nghip ha cht, ch bin du m;

- C sn phm phn hy cy c, rong to, ng vt

4.1.3.2 Thnh phn v tnh cht nc thi

4.1.3.2 Thnh phn v tnh cht nc thi

Thnh phn vt l: c chia thnh 3 nhm ty vo kch thc:

- Nhm 1: gm cc cht khng tan dng th ( vi, giy, cnh l cy, sn si, ct, da, lng); dng l lng (> 10-1mm), dng huyn ph, nh tng, bt ( =10-1 10-4mm)

- Nhm 2: gm cc cht bn dng keo (= 10-4 10-6mm);

- Nhm 3: gm cc cht bn dng ha tan

4.1.3.2 Thnh phn v tnh cht nc thi (tt)

Thnh phn ha hc: cc cht bn c cc tnh cht ha hc khc nhau, c chia thnh 2 nhm:

- Thnh phn v c: ct, st, x, axit v c, kim v c, cc ion ca cc mui phn ly;

- Thnh phn hu c: cc cht c ngun gc t ng vt, thc vt, cn b bi tit:

+ Cc hp cht cha nit: ure, protein, amin, acid amin

+ Cc hp cht nhm hydratcarbon: m, x phng, cellulose

+ Cc hp cht c cha phospho, lu hunh

Thnh phn sinh hc: cc cht bn c trong nc thi c kh nng gy bnh hoc khng gy bnh

4.1.3.2 Thnh phn v tnh cht nc thi (tt)

4.1.4 Cc phng php x l nc thi

p ng cc tiu chun cht lng ca nc thi trc khi x vo ngun tip nhn, nc thi t cc khu dn c, t nh my cng nghip, t cc cng s v khu thng mi phi c thu gom bng h thng cng, dn n ni tp trung ( nh my x l) x l

Chn la phng php, qu trnh x l:

Thng s thit k:

- BOD5 cao x l sinh hc;

- SS cao phng php c/ ha-l;

- N,P cao phng php sinh hc/ha-l

Ngun x, tiu chun x ra mi trng:

- X ra sng/h;

- X ra bin

- S dng li : Cng nghip, Nng nghip

4.1.4 Cc phng php x l nc thi Theo c tnh ca quy trnh x l:

- Phng php c hc: lng cn, lc qua li lc, lc qua vt liu lc, khuy trn pha long

- Phng php ha l: ng t, keo t, hp ph, tuyn ni, trao i ion

- Phng php ha hc: trung ha, oxi ha kh, clo ha, ozon ha

- Phng php sinh hc: x l hiu kh, x l ym kh

4.1.4 Cc phng php x l nc thi

Theo cng on x l:

- X l bc mt ( x l s b): song chn rc, b lng, b tch du, trung ha nc thi Tch cc cht khng tan cc cht nhim ra khi nc thi

- X l bc hai ( x l sinh hc, ha l); oxy ha sinh ha cc cht hu c dng tan, keo v khng tan nhng khng lng c

- X l bc ba : thng c thc hin theo yu cu x l c cht lng cao hn. p dng cc bin php nh trit khun, kh tip cc cht bn cn li trong nc thi nh nitrat, photphat, sunphat, lc than hot tnh

- X l bn cn trong nc thi;

4.1.4 Cc phng php x l nc thi (tt)

Cc cng trnh trong h thng x l bc mt, hai, ba Cht cn x l X l bc mt X l bc hai X l bc ba

pH Trung ha

Cht l lng v cn Song, li chn, lng s b Keo t, lng lc

BOD Lng, ln men metan trong cc b t hoi

-B x l bng bn hot tnh; -B lc sinh hc; -H sinh hc;

-Hp th bng than hot tnh; - Lc qua mng thm thu ngc;

COD Lng, ln men metan trong cc b t hoi

-B x l bng bn hot tnh; -B lc sinh hc; -H sinh hc;

-Hp th bng than hot tnh; - Lc qua mng thm thu ngc. Oxy ha bng Cl, H2O2, O3, KMnO4

Du m B tch du bng trng lc Keo t v tuyn ni

Phenol Bn hot tnh Hp th bng than hot tnh

Cyanua Phn hy bng cc cht oxy ha, x l bng bn hot tnh

-in phn; - Lc qua mng thm thu ngc

Crom -Kh Cr thnh Cr3; - Keo t v lng

-Lc trao i ion; -in phn; -Lc qua mng thm thu;

St, mangan -Lm thong oxy ha; -Oxy ha, lng lc;

-Lc trao i ion; -in phn;

Kim loi nng Keo t, lng lc, oxy ha kh -Trao i ion; -in phn; -Lc qua mng thm thu;

Clo v HC clo Trung ha bng kim Hp th bng than hot tnh

Nguyn t dd N, P -Bn hot tnh; -Oxy ha bng ha cht

-Lc thm thu ngc

Mi -Bn hot tnh; -Oxy ha bng ha cht

Hp th bng than hot tnh

Mu Oxy ha kh keo t v lng -Hp th bng than hot tnh; - Lc qua mng thm thu ngc

4.1.5 Tc hi ca nc thi

Nu khng kim sot v qun l tt cc dng nc thi s gy nn nhiu vn :

- Ngp ng ng ph;

- nhim mi trng v nhim ngun nc;

- Ph v mi cn bng sinh thi t nhin;

- Lm mt i v m quan ca cc trung tm th;

bo v mi trng v duy tr cc iu kin sng trong lnh, cc ngun nc thi cn phi c kim sot v qun l nghim ngt;

4.1.4 Tc hi ca nc thi

4.1.5 TC HI CA NC THI

4.2 LU LNG V NNG CHT BN TRONG NC THI

4.2.1 Lu lng nc thi cho khu dn c Lng nc thi cho mt ngi = 60-90% lng nc cp

tiu th cho mt ngi. Lu lng nc thi ph thuc vo: - Lng nc cp; - Gi nc; - iu kin kinh t x hi ca cng ng; - iu kin t nhin ( kh hu); Lu lng nc thi cho khu dn c c xc nh da trn: - i vi th c: da trn s liu nc cp= 60-90% nc

cp tiu th. - th mi: da trn s dn/ s hoch v tiu chun thi nc: + Nh c vi tm hoa sen: 100-120 l/ngi.ngy; + Nh c bn tm: 200-250l/ngi.ngy; +Khu du lch/resort: 400-600l/ngi. ngy

4.2.2 Lu lng nc thi cho cng trnh

4.2.2 LU LNG NC THI CHO CNG TRNH

4.2.3 Ti lng nhim Mc nhim do nc thi c nh gi qua thng

s ti lng nhim theo thnh phn ( BOD5, SS, COD)

Li=Q*Ci

Li - ti lng nhim, kg/ng;

Q- Lu lng nc thi, m3/ng;

Ci Nng thnh phn trong dng thi, kg/m3

STT Ch tiu nhim c trng

n v Nng NT nh my ma ng trc x l

QCVN

24:2009/BTNMT, ct B

1 pH 5-9 5,5-9

2 BOD mg/l 2759 50

3 COD mg/l 5200 100

4 SS mg/l 623 100

5 Tng N mg/l 15,4 30

6 Tng Photpho mg/l

20,5 6

4.3 X L NC THI BNG PHNG PHP C HC

4.3.1 Song chn rc (SCR)

4.3.1.1 V tr

SCR b tr ti mng dn nc thi trc trm bm nc thi v trc cc cng trnh XLNT

4.3.1 Song chn rc (SCR) (tt)

4.3.1.2 Chc nng

- Gi li cc tp cht th nh giy, rc, ti nilon, v cy v cc tp cht ln c trong NT

- Nhm m bo cho my bm, van, ng ng, cc cng trnh v thit b XLNT hot ng n nh


4.3.1.3 Phn loi

SCR l cc thanh an sp xp k nhau vi khe h t 10-100mm, cc thanh c th bng thp, nha hoc g.

Theo cch vt rc:

- SCR vt th cng, dng cho cc trm XLNT cng sut nh, lng rc hng ngy di 0,1 m3 /ngy.

- SCR vt rc c gii bng cc bng co dng cho trm XLNT c lng rc ln hn 0,1 m3 /ngy.

Theo khe h thanh chn:

- SCR th: b= 60-100mm;

- SCR tinh: b= 10-20 mm;

Rc c vt 2-3 ln trong ngy v c nghin a v b bn hoc x trc tip pha trc thit b. Trng hp lng rc nh, c th tp trung vo thng cha thu cc cng ty mi trng th vn chuyn v bi chn lp.


4.3.2 B lng ct

4.3.1.1 V tr

B lng ct thng c t pha sau thit b chn rc v trc b lng s cp.

4.3.2 B lng ct (tt) 4.3.2.2 Chc nng Cn nng/ct: - Ht nh, nng nh ct si. - Kch thc ht > 200 mm Chc nng: - Loi b cc tp cht rn v c khng tan ra khi

nc thi - Bo v cc trang thit b c kh ng ( bm) trnh b

mi mn.

- Gim cn lng trong ng, mng dn v b phn hy.

- Gim tn sut lm sch b phn hy. - m bo cho cc cng trnh XLNT hot ng n

nh

4.3.2 B lng ct (tt)

4.3.2.3 Phn loi

- B lng ct ngang;

- B lng ct ng;

- B lng ct c sc kh;

A. B lng ct ngang

- Chiu su ca b 0,25-1 (m), t l B/H = 1:2.

- BLC ngang l on m rng ca mng dn nc thi, c h tp trung ct pha u.

- S dng khi lng NT>100m3/ngy;

- Vn tc ca dng NT ( 0,15

B. B lng ct ng

- BLC ng c hnh tr hoc lng tr ng, NT c dn vo pha di y ra khi b pha trn.

- Thi gian lu nc t 2-3,5 pht;

C. B lng ct c sc kh

- Chuyn ng quay trong b lng ct thi kh thc hin c nh cc ng thi kh nn t dc theo tng b.

- B c dng hnh ch nht; Thi gian lu NT 2-5 pht

- Cng thi kh 3-5 m3 kh/ m2 b.h;

- B thng c dng cho cc trm XLNT cng sut ln, trn 20.000 m3/ngy.; tch c cht hu c ra khi ct

- Cc ng phn phi kh t cch y b 0,45-0,6m;

- Chiu su ti thiu 2 (m), t l gia chiu rng v chiu su 1,5:1


4.3.3 B lng

4.3.3.1 V tr

B lng dng x l s b NT ( x l bc mt) trc khi x l sinh hc hoc nh mt cng trnh x l c lp nu ch yu cu tch cc loi cn lng khi NT trc khi x ra ngun nc mt.

4.3.3 B lng (tt)

4.3.3.2 Chc nng

- Tch cn bng trng lc;

- Kh SS trong nc thi ( b lng I);

- Kh bng cn trong qu trnh keo t-to bng;

- Lng bng bn hot tnh/mng vi sinh ( b lng t II)

4.3.3.3 Phn loi

Da vo chc nng v v tr c th chia b lng thnh hai loi:

- B lng t I trc cng trnh x l sinh hc ( tch cn s cp);

- B lng t hai sau cng trnh x l sinh hc nc thi ( tch bn th cp)

Theo cu to v hng dng chy ngi ta phn ra ba loi:

- B lng ngang;

- B lng ng;

- B lng trn;

A. B lng ngang

- Hnh dng: Hnh ch nht, chiu su H=1,5-4 (m), chiu rng B=3-6(m), chiu di L=(8-12)H.

- Cu to: B phn phn phi nc vo b, vng cn lng, h thng thu nc lng, h thng thu x cn.

- Nguyn tc hot ng: nc c phn phi u u b chuyn ng ngang, dc theo chiu di b v nc thi ra u kia ca b. Cc ht cn c tp trung v u b nh h thng gt cn.

- Lu lng nc thi trn 15000m3/ngy.

- Hiu sut lng t 60%.

- Vn tc dng nc thi trong b lng thng khng ln hn 0,01m/s.

- Thi gian lu t 1-3 gi.

- Ni xy dng ngoi tri v i hi c din tch ln

A. B LNG NGANG

B. B lng ng - Hnh dng: Hnh hp hoc hnh tr y dng nn hay

chp ct; - Cu to: ng dn nc vo, ng phn phi nc trung

tm , mng thu nc, ng dn nc ra, ng x cn; - Nguyn tc hot ng: nc c a vo b, qua

ng phn phi trung tm chuyn ng theo phng thng ng t di ln trn. Nc lng trong trn qua mng thu t xung quanh thnh b ra ngoi, Cn lng xung y v c thi b ra ngoi;

- Thi gian nc lu li trong b 45-120 pht; - NT c a vo ng phn phi tm b vi vn tc

khng qu 30mm/s;

- NT chuyn ng t di ln trn ti vch trn vi vn tc 0,5-0,6 m/s;

- Hiu sut lng 45-48%; - B c din tch xy dng nh, d x bn cn

B. B LNG NG

C. B lng trn ( b lng ly tm)

- Hnh dng: c tit din hnh trn, D=16-40m (c trng hp n 60m), t l D/H=6-30.

- Cu to: ng dn nc vo, ng phn phi nc trung tm , mng thu nc, ng dn nc ra, ng x cn, cnh gt bt, ngn thu bt ni, sn cng tc, ng c, vch hng dng.

- Nguyn tc hot ng: NT c dn vo b, chuyn ng theo chiu t tm ra thnh b. Cn lng xung y, c tp trung li nh h thng gt cn quay trn. Cht ni nh tm chn l lng di dn quay dn gp li. Nc trong c thu vo mng tp trung ri dn ra ngoi

- Thi gian lu nc trong b lng 85-90 pht;

- Hiu sut lng 50-60%;

- Lng ngun nc c hm lng cn cao>2,000mg/l, thch hp vi cng sut >20,000m3/ngy.

C. B LNG TRN( B LNG LY TM)


4.3.4 Lc V tr : Sau cc b lng Chc nng: Tch cc tp cht c kch thc nh m qu

trnh lng khng th thc hin c ra khi NT. C ch: dng NT chy qua lp VL lc ( lp ngn xp),

cc ht rn s c gi li v nc thot qua lp VL lc ra ngoi

Phn loi vt liu lc: - Li kim loi; - Cc loi vi lc ( bng , len, si tng hp); - VL lc dng ht ( than cc, si nghin, than nu) Yu cu i vi vt liu lc: - Bn ha hc, bn c hc, bn nhit ; - Kh chy n; - Kh lm bn; - D ti sinh

4.3.4 B lc

Phn loi thit b lc: TB lc gin on: - Lc ht; - Lc tm; - Lc p; TB lc lin tc: - Lc hnh trng; - Lc a; - Lc bng Theo tc : - B lc chm: 0,1-0,5m/h; - B lc nhanh: 5-15m/h; - B lc cao tc: 30-100m/h; Theo ch lm vic: - B lc trng lc: - B lc c p lc: lc kn


4.3.5 B iu ha 4.3.5.1 V tr Trc cc cng trnh XLNT, sau SCR, i vi nc thi c hm lng

cht rn l lng v du m cao, v tr t b iu ha sau b lng ct, sau b lng t 1

4.3.5.2 Chc nng: -n nh lu lng NT; -n nh nng cc cht nhim trong NT; - Khi lu lng NT a v cc cng trnh XLNT n nh kch thc

cng trnh s nh v hp l gi thnh xy dng trm XLNT nh hiu qu kinh t ca trm XLNT s ln.

4.3.5.3 Phn loi: Theo chc nng - B iu ha lu lng - B iu ha nng - B iu ha ng thi c lu lng v nng cc cht nhim

4.3.5 B iu ha (tt) 4.3.5.3 Phn loi:

Theo ch hot ng

- B iu ha hot ng gin on ( theo chu k);

- B iu ha hot ng lin tc;

Theo nguyn tc chuyn ng ca nc: trong b iu ha hot ng lin tc, ngi ta chia ra:

-B iu ha hot ng theo nguyn tc y ( ch chy tng);

-B iu ha hot ng theo nguyn tc xo trn ( ch chy ri).

chng hin tng lng cn trong b iu ha, ngi ta phi b tr cc thit b khuy trn bng kh nn, my khuy trc ngang hoc trc ng

CC THIT B KHUY TRN KH TRONG B IU HA

THIT B BM SC KH CHM

THIT B PHN PHI KH

4.3.5 B iu ha (tt)

4.4 X L NC THI BNG PHNG PHP HA HC

4.4.1 Trung Ha nc thi

4.4.1.1 Mc ch

Ngn nga hin tng xm thc;

c th x l NT bng phng php sinh hc;

Tch mt s ion kim loi nng ra khi NT

4.4.1.2 Phn loi

Trn nc thi c tnh axit vi nc thi c tnh kim;

a ha cht vo trung ha;

Trung ha nc thi axit bng cch cho chy qua lp vt liu trung ha;

Dng kh thi cha cc oxit axit trung ha nc thi cha kim;


4.4.1.3 C ch

A. Kh nng t trung ha ln nhau gia cc dng NT

c dng khi nc thi ca 2 nh my gn nhau, hoc cng 1 nh my c tnh cht i lp nhau;

Khuy trn nc thi trong thng cha;


4.4.1.3 C ch (tt)

B. B sung ha cht trung ha nc thi

NT c tnh axit:

- Vi (CaO); - Nc amoniac (NH4OH)

- Xt (NaOH); - vi (CaCO3);

- Vi ti (Ca(OH)2; - olomit (CaCO3.MgCO3)

- Soda (Na2CO3);

NT c tnh kim:

- S dng cc axit khc nhau (H2SO4, HCl);

- Hoc kh thi mang tnh axit (CO2, SO2);


4.4.1.3 C ch (tt)

B. B sung ha cht trung ha nc thi


4.4.1.3 C ch (tt)

C. Lc qua lp VL c tc dng trung ha

Trung ha nc axit c nng axit


4.4.1.3 C ch (tt)

C. Lc qua lp VL c tc dng trung ha


4.4.1.3 C ch (tt) D. Trung ha NT cha kim bng cc kh thi cha cc oxit axit

- Ngun kh thi (CO2,SO2,NO2,N2O3..);

- Gim chi ph ng k;

- Tc ng n mn v c hi ca cc ion CO3 nh trong nc nh hn so vi SO4 v Cl .

- Gim CO2 gim hiu ng nh knh

4.4.2 Phng php oxi ha kh lm sch nc, ngi ta s dng cc cht oxy ha sau: Cl2 kh v

lng, Ca(OCl)2, Ca(ClO3)2 v NaClO3, KMnO4, K2CrO7, H2O2, O2, O3, piroluzit MnO2.

Trong qu trnh oxy ha, cc cht nhim c hi cha trong nc thi s chuyn thnh cht t c hn v c loi ra khi nc

4.4.2.1 XLNT cha xianua

Dng clo trong mi trng kim (pH=9);

CN + 2OH + Cl2 CNO + 2Cl + H2O

2 CNO + 4OH + Cl2 2CO2 + 2Cl +N2 + 2H2O

Dng hypoclorua

CN + OCl CNO + Cl

2 CNO + 3OCl +H2O 2CO2 + N2 + 2OH + 3Cl

Ozon ha cc xianua

CN + O3 CNO + O2

CNO + 2H2O HCO3 +NH3

2CN + 3O3 + H2O 3HCO3 + 3O2 +N2

4.4.2 Phng php oxi ha kh

4.4.2.2 XLNT cha st v mangan Dng clo

2Fe + Cl2 + 6H2O Fe(OH)3 + 2Cl + 6H

Mn + Cl2 + 2H2O MnO2 + 2Cl + 4H

Dng Oxy ca khng kh

4Fe + O2 + 10H2O 4Fe(OH)3 + 8H

2Mn + O2 + 2H2O 2MnO2 + 4H

Dng KMnO4

2Fe + KMnO4 + 7H2O 3Fe(OH)3 + MnO2 + K + 5H

Mn + 2KMnO4 + 2H2O 5MnO2 + 2K + 4H

Dng H2O2

Fe + H2O2 + 2H Fe3 +2H2O

Mn + H2O2 + 2H MnO2 + 2H2O

4.4.2.3 XLNT cha Asen Dng pyroluzit

H3AsO3 + MnO2 + H2SO4 H3AsO4 + MnSO4 +H2O

4.4.2 Phng php oxi ha kh

4.4.2.4 XLNT cha Crom Dng SO2

SO2 + H2O H2SO3

2CrO3 + 3H2SO3 Cr2(SO4)3 + 3H2O

Dng st sunfat

2CrO3 + 6 FeSO4 + 6Ca(OH)2 +6H2O 2Cr(OH)3 +6Fe(OH)3 +CaSO4

Dng dung dch natri bisunfat:

4H2CrO4 + 6NaHSO3 + 3H2SO4 2Cr2(SO4)3 + 3Na2SO4 + 10H2O

Cr3 + 3OH Cr(OH)3

4.4.2.5 XLNT cha Clo

Dng H2O2

H2O2 + Cl2 2HCl + O2

H2O2 + NaOCl NaCl + O2 + H2O

MnO2 + H2O2 + 2HCl MnCl2 + 2H2O + O2

4.5 X L NC THI BNG PHNG PHP HA L

4.5.1 Keo t to bng

4.5.1.1 Mc ch

Trong nc tn ti nhiu cht l lng khc nhau. Kh mu. Cc cht ny c th dng phng php x l khc nhau ty vo kch thc ca chng:

d>10 mm: dng phng php lng lc.

d

KT BNG-SA LNG

4.5.1 Keo t to bng

4.5.1.2 Cht keo t a. Phn nhm Al2(SO4)3 : cho vo nc chng phn ly thnh

Al 3 + 3H2O Al(OH)3 +3H

pH ca nc nh hng trc tip n kt qu thy phn:

- pH7.5 : hiu qu keo t khng tt

Nhit c ca nc thch hp vo khong 20-40C, tt nht 35-40 C.

Ngoi ra cc yu t nh hng khc nh: thnh phn ion, cht hu c, liu lng

4.5.1 Keo t to bng

4.5.1.2 Cht keo t B. Poly nhm clorua (PAC) :

- Hm lng Al cao hn;

- Khi ha tan vo nc khng lm gim pH nh cc loi phn nhm

khc [AlClx(OH)3-x]n ; x=1-2

- Phn t lng 7500-35000;

- Liu lng 1g/1l NT

C. Mui st II: FeSO4

Fe + 2H2O Fe(OH)2 + 2H;

C oxi trong nc: Fe(OH)3

pH=8-9 : t tt nht

D. Mui st III: Fe2(SO4)3, FeCl3

Fe3 + 3H2O Fe(OH)3 + 3H;

Phn ng xy ra khi pH>3,5;

Hnh thnh lng nhanh khi pH=5.5-6.5

4.5.1 Keo t to bng

4.5.1.2 Cht keo t

So snh phn st v phn nhm:

- ha tan phn st < phn nhm;

- Phn st tc dng tt hn nhit thp;

- Lng phn st dng =(1/2-1/3) lng phn nhm;

- bn ca bng keo ln hn;

- Kh c mi ( H2S nu c);

- Phn st n mn ng ng

- Trong x l nc thi, s dng hn hp mui nhm v mui st vi t l t 1:1 n 1:2 th kt qu ng t tt hn l s dng ring l.

4.5.1 Keo t to bng

Cht tr keo t: cho thm cht tr keo t vo nc s y nhanh qu trnh keo t v to bng cn to, nng lng. L nhng polymer tng hp phn nhnh, khi lng phn t ln, tan trong nc v d phn ly thnh ion. Polyacrylamin (CH2CHCONH2)n

Axit silic hot tnh l polyme chui ngn c tc dng bao cc ht cn hydroxit nhm thu ht cc ht keo. Liu lng gii hn khong 5-10mg/l.

ky thuat moi truong-dh11hd 336tr.pdf

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