Do an xử lý nước ngầm

8/12/2019 Do an x l nc ngm

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N MN H CTnh ton v thi t k tr m x l n c ng m b sung cho mng l i cp n c Tp H Ch MinhQ=1000m3 /ngym

SVTH: Tr n Phong Khng MSSV:0310020158GVHD:L Vi n L p

1

LI NI U

Cng nh khng kh v nh sng, n c khng th thiu c trong cuc sngca con ng i. Trong qu trnh hnh thnh s sng trn tri t th nc v mi tr ngnc ng vai tr rt quan tr ng. N c tham gia vo qu trnh ti sinh th gi i hu c. Ngun n c l c s ca s hnh thnh v tch ly cht hu c s sinh l hin t ngquang hp c thc hin d i tc dng ca nng l ng mt tr i v i s gp phn canc v khng kh. Trong qu trnh trao i cht, n c c vai tr trung tm. Nhng phnng l, ha hc din ra v i s tham gia bt buc ca nc. N c l dung mi car t nhiu cht v ng vai tr dn ng cho cc mui i vo c th.

Trong cc khu dn c, n c phc v cho cc mc ch sinh hot, nng cao isng tinh thn ca ng i dn. Nc cn ng vai tr rt quan tr ng trong sn xut, phc v cho hng lot ngnh cng nghi p khc nhau.

i v i cy tr ng, n c l nhu cu thit yu ng thi cn ng vai tr iu titcc ch nhit, nh sng, cht dinh d ng, vi sinh vt, thong kh trong t, lnhn t quan tr ng cho s pht trin ca thc vt.

Trong gi i hn ti: Tnh ton thit k tr m x l n c ngm cung c p chomng l i cp n c cho thnh ph H Ch Minh c cng sut 1000m3/ngym ems c gng tm hiu, tnh ton, thit k tr m x l n c ngm. V qua xut ra ccgii php XLNC ph hp, ng th i gip mi ng i hiu r thm v tm quan tr ngca n c ni chung v ngnh x l n c cp ni ring. m bo v vn n c schkhng ch Vit Nam m trn ton Th gii hng n s PTBV.

Trn tr ng knh cho.

SVTH: Tr n Phong Khng


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NHN XT CA GVHD

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GVHD


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MC LC

LI NI U ............................................................................................................ 1LI CM N............................................................................................................. 2

NH N XT CA GVHD .......................................................................................... 3

MC LC .................................................................................................................. 4

DANH MC HNH ................................................................................................... 7

DANH MC B NG .................................................................................................. 8

DANH MC CH VIT TT .................................................................................. 9

CHNG I................................................................................................................. 10

T NG QUAN V NC NGM NH GI CHT L NG NGUN NCCP CHO SINH HOT ............................................................................................ 10

1.1. T NG QUAN V NC NGM ..................................................................... 10

1.2. C IM, THNH PH N, TNH CHT CA NC NGM DNG

LM NC CP ...................................................................................................... 12

1.2.1. Thnh phn v tnh cht ca n c ngm .......................................................... 121.2.2.nh h ng ca cc cht i v i cht lng n c, s nhim n c ............... 13

1.2.2.1. Cc tc nhn v thng s nhim ha l ngun n c ................................... 14

1.2.2.2. Cc tc nhn v thng s ha hc gy nhim ngun n c ........................ 16

1.3. CC CH TIU V THNG S NH GI CHT LNG NC .......... 18

1.3.1. Cc ch tiu vt l .............................................................................................. 18

1.3.2. Cc thng s ha hc ........................................................................................ 181.3.3. Cc ch tiu vi sinh ........................................................................................... 19

1.4. NNG GII H N CHO PHP CA CC CHT C C HI CTRONG NGUN NC PHC V CP NC SINH HOT ............................ 19

1.4.1. Quy chun k thut quc gia v cht lng n c sinh hot ( QCVN02:2009/BYT) ............................................................................................................. 19

1.4.2. Quy chun k thut quc gia v cht lng nc n ung (QCVN

01:2009/BYT) ............................................................................................................. 22


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2.6.3. Phng php ha hc ....................................................................................... 45

CHNG III.............................................................................................................. 46

XUT PHNG N X L V TNH TON CNG TRNH N V ........ 463.1. C S L A CH N QUY TRNH CNG NGH ............................................ 46

3.2. XUT QUY TRNH CNG NGH ............................................................ 47

3.2.1. Phng n 1...................................................................................................... 47

3.2.2. Phng n 2...................................................................................................... 49

3.3. TNH TON CNG TRNH N V ............................................................... 50

3.3.1. Tnh ton b lng ngang ................................................................................... 503.3.2. Tnh ton b lc p lc ..................................................................................... 56

3.3.3. Tnh ton gin ma........................................................................................... 59

3.3.4. Tnh ton b cha n c sch ............................................................................ 59

3.3.5. Tnh l ng clo cn dng kh trng ............................................................. 59

CHNG IV.............................................................................................................. 61

K T LU N V KI N NGH .................................................................................... 61TI LIU THAM KHO .......................................................................................... 62

B N V ..................................................................................................................... 63


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DANH MC HNH

B NG 2-1: Qu trnh lm thong .......................................................................... 33

B NG 3-1: S quy trnh cng ngh phng n 1............................................. 48

B NG 3-2: S quy trnh cng ngh phng n 2............................................. 49


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DANH MC BNG

B NG 1-1: Mt s nt khc bit gia n c mt v n c ngm ............................ 11

B NG 1-2: Mt s bnh ng i do nhim ngun n c gy ra ......................... 13

B NG 1-3: Quy chun k thut quc gia v cht lng n c sinh hot (QCVN02:2009/BYT) ......................................................................................................... 20

B NG 1-4: Quy chun k thut quc gia v cht lng nc n ung (QCVN01:2009/BYT) ......................................................................................................... 22

B NG 1-5: Bng thng s nc u vo ca ngun n c ngm .......................... 28

B NG 3-1: Bng thng s nc u vo ............................................................... 46B NG 3-2: Thng s nc u ra theo QCVN 02:2009/BYT .............................. 47

B NG 3-3: Tr s K v ph thuc vo t s L/H .............................................. 51

B NG 3-4: Trch bng 6.8 trang 36 TCXD 33:2006 ............................................. 54

B NG 3-5: Trch bng 4.10 trang 153 x l n c c p TS Nguyn Ngc Dung .............................................................................................................. 57


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DANH MC CH VIT TT

PTBV: Pht trin bn vng

TCXD: Tiu chun xy dng

QCVN: Quy chun Vit Nam

XLNC: X l n c c p

BVTV: Ha cht bo v thc vt

TCVN: Tiu chun Vit Nam

BYT: B y t


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CHNG I: TNG QUAN V N C NGM NH GI CHTL NG NGUN N C CP CHO SINH HOT

1.1. T NG QUAN V NC NGM.

N c l mt nhu cu thit yu trong i sng ca sinh vt, n tham gia vo miqu trnh t nhin, nc c x dng phc v trong cc lnh vc sinh hot v hotng sn xut ca con ng i.

Vit Nam l mt quc gia c ngun n c ngm kh phong ph v tr l ng v khtt v cht l ng.Ti Vit Nam, nc s dng cho sinh hot l 70% nc mt v 30%nc ngm.Tuy nhin, trong nhng nm gn y do khai thc qu mc nn mch nngm ti mt s thnh ph ln nh H Ni, TP. H Ch Minh b nhim cc chthu c v gy st ln. cc vng ven bin nc ging khoan ho mn v tnh trnnhim mn ngy cng gia tng. Dn s th gii ang tip tc tng, cng nghip ho, th ho thm canh nng nghip s dng nc ngy cng nhiu, trong khi s lngnc v cht lng nc ang ngy cng gim st gy kh khn cho nhiu quc gia,theo d bo n nm 2030 c khong 60 quc gia thiu nc trm trng.

Ngun nc ma,n c mt v hi nc trong khng kh ngng t li v thmthu vo lng t to thnh n c ngm. N c ngm c gi li hoc chuyn ngtrong cc l r ng hay khe nt ca cc tng t to nn tng ngm nc. N c ngmc th tn ti cch mt t vi mt, vi chc mt hay hng ngn mt

Trong qu trnh sng v pht trin, con ng i cn mt lng n c nht nh chosinh hot v lng n c tiu tn ph thuc vo nhu cu s dng. X hi cng tng thnhu cu dng nc cng tng. Nhu cu nc bnh qun u ng i ti thiu l 50

lt/ngym. Nhng cc n c pht trin th con s ny ln n 500 lt/ngym (vd: tiu chun cp n c sinh hot ca M l 380 500 lt/ngym, Php l 250 500 lt/ngym, Singapore l 250 400 lt/ngym). Cc thnh ph l n Vit Nam cng c nhu cu cao v s dng nc cao hn nhiu so v i khu vc nng thn,nh H Ni v Thnh ph H Ch Minh phn u t bnh qun khong 200 250lt/ngym. Ngun n c s dng cho sinh hot ca con ngi cng c phn chia ranhiu loi khc nhau: n c dng cho nhu cu n ung i hi phi c cht l ng cao, bo m khng gynh hng n sc khe ng i s dng n c,cc ngun n cdng cho nhu cu tm, git, r a c th c yu cu thp hn.


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N c trong t nhin c s dng c p cho sinh hot v cc hot ng snxut c cht lng khc nhau. i vi n c mt thng c c, mu v hm

l ng visinh vt cao. Hu ht cc ngun n c ngm li cha nhiu st v manganC th ningun n c t nhin khng th p ng c yu cu v cht l ng. V vy, cn thit phi bit c thnh phn ca chng tin hnh x l nhm t yu cu v chtlng, p ng nhu cu v mc ch s dng n c.

i v i h thng cp n c cng ng th ngun n c ngm lun l ngun n cc a thch. B i v cc ngun n c mt th ng b nhim v lu l ng khai thc phi ph thuc vo s bin ng theo ma. Ngun n c ngm t chunh h ng b i

cc tc ng ca con ng i, cht lng n c ngm tt h n cht lng n c mt nhiu.Trong n c ngm hu nh khng c cc ht keo hay cc ht l lng v vi sinh vt, vitrng gy bnh th p.

B ng 1-1: M t s nt khc bi t gi a n c m t v n c ng m

c tnh N c mt N c ngm Nhit cCht khong ha

tanFe2+, Mn2+ CO2 ha tanO2 ha tan NH4+ SiO2 Vi sinh vt

Thay i theo maCao, thay i theo maThay i theo cht lng t v

lng ma R t th pR t th pGn nh bo ha Khi n c b nhim bn Nng mc trung bnhVi trng, vi rt cc loi, rongto

Tng i n nhTh p hoc khng ct thay i, cao hn n c mt

ca khu vcTh ng xuyn c Nng tng i caoGn nh khng c Th ng xuyn c mt Nng caoC th c vi khun do st gyra

Cc ngun n c ngm hu nhkhng cha rong to (mt trong nhng nguyn

nhn gy nhim ngun n c), thnh phn ng quan tm trong n c ngm l cc t pcht ha tan donh h ng ca iu kin a tng, th i tit (nng, ma), cc qutrnh phong ha v sinh ha trong khu vc. nhng vng c iu kin phong ha tt,c nhiu cht bn v lng ma l n th cht lng n c ngm d b nhim b i cccht ha tan, cc cht hu c, mn lu ngy theo nc ma thm vo t.

Ngoi ra n c ngm cng c th b nhim bn do cc tc ng ca con ng i. Cccht thi ca con ngi v ng vt, cc cht thi sinh hot, cc cht thi ha hc vvic s dng phn ha hcTt c nhng loi cht theo th i gian n s ngm vo

v lm nhim ngun n c ngm. khng c t ngun n c ngm do tc ng ca


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con ngi b nhim do cc cht hu c kh phn hy, cc vi khun gy bnh, nhtl ha cht c hi nh cc kim loi nng, d l ng thuc tr su v khng loi tr

cc cht phng x.1.2. C IM, THNH PH N, TNH CHT CA NC NGM DNG

LM NC CP. c im ca n c ngm:

Nc ngm c khai thc t cc tng cha nc di t, cht lng nc n ph thuc vo thnh phn khong ha v cu trc a tng m nc thm qua. Do ,nc chy qua cc tng t cha ct v granit thng c tnh axit v cha t cht khong. Khi nc chy qua cc tng t cha vi th nc thng c cng v

kim Hydrocacbonat cao. Ngoi ra, c trng ca nc ngm l: - c thp.

- Nhit v thnh phn ha hc tng i n nh.

- Khng c cha oxy nhng cha nhiu kh nh: CO2, H2S,

- Cha nhiu khong cht ha tan ch yu l st, mangan, canxi, magie, flo.

- Khng c hin din ca vi sinh vt.

u im ca ngun n c ngm l: ngun n c r t trong sch, hm l ng cnnh, t vi trng x l n gin, gi thnh r . Nhc im: thm d lu, kh khn. Th ng cha nhiu st, mangan v b

nhim mn vng ven bin x l kh v phc t p.1.2.1. Thnh phn v tnh cht ca n c ngm.

Ngun n c ngm th ng t chunh h ng ca cc yu t con ng i. V vy,thnh phn v tnh cht ca n cng n nh hn v cht lng th ng tt hn n c b mt. Thnh phn v tnh cht ca n c ngm ph thuc vo ngun gc, cu trc a

tng ca khu vc v chiu su ca lp n c ngmTrong n c ngm khng charong to( l yu t d gy nhim ngun nc). Nhng chng li cha cc t p chtha tan donh h ng ca iu kin a tng, cc qu trnh phong ha v sinh hatrong khu vc. nhng vng c iu kin phong ha tt, ma nhiu hoc b nhh ng ca ngun thi th trong n c ngm d b nhim b i cc cht khong ha tan,cc cht hu c.


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Bn cht a cht khu vc nh h ng ln n thnh phn ha hc ca n cngm v n c lun lun ti p xc vi t , trong n c th lu thng hoc gi li.

Gia nc v t lun hnh thnh nn s cn bng v thnh phn ha hc, v vy thnh phn ca n c th hin thnh phn a tng ca khu vc . Tuy vy, n c ngm cc tnh chung l: c th p, nhit v thnh phn ha hc t thay i theo th igian ngoi ra n c ngm cn r t t vi khun, tr tr ng h p ngun n c b nh h ngca n c b mt.

- N c tng nng c tr l ng th p, khng p, d b nhim bn. V ng c li iv i tng su tr l ng cao, c p v kh nng nhim bn thp hn.

- N c ngm thng khng c oxi ha tan, nhng c nhiu CO2 v cc cht ha

tan (st, mangan, asen). - pH n c ngm kh thp, thng dao ng t 3 6- s c mt ca mt s thnh phn nhim ca ngun n c ngm ni (hm

lng phospho, nit, E.coli) 1.2.2. nh h ng ca cc cht i v i cht lng n c, s nhim n c.

Cc hot ng nhn to hoc t nhin cnh h ng ln n cht lng n c. Ccngun t nhin nh xi mn, l lt, cc hot ng nhn to nh n c thi t sinhhot, cng nghi p, nng nghi p, cc hnh vi ph hoiC th a vo mi tr ng

n c nhiu loi cht khc nhau, dn n tnh tr ng nhim mi trng n c. Lmthay i thnh phn v tnh cht ca n c gynh hng n hot ng sng bnhth ng ca con ng i v sinh vt.

B ng 1-2:M t s b nh ng i do nhi m ngu n n c gy ra

Bnh Tc nhn truyn bnh Loi sinhvt

Triu ch ng

Dch t Vibrio cholerae Vi khun Tiu chy nng, nn ma,c th mt nhiu n c, b chut rt v suy sp cth

Kit l Shigella dysenteriac Vi khun Ly nhim rut gy bnhtiu chy vi n c nhy

Vim rut Clostridium perfringensv vi khun khc

Vi khun Lm chy rut non gykh chu, nkhng ngonhay b tiu chy

Thnghn

Salmonella typhi Vi khun au u mt nng l ng

Siu vi trng vim gan A Siu vi t cht gan, vng da, n


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trng khng ngon, au uBi lit Siu vi trng bi lit Siu vi

trngau cung hng, tiuchy, auct sng vchn tay

Kit l doamip Entamoeba histolytica Amip Ly nhim rut gy bnhtiu chy vi n c nhy

S NHIM NC

Theo bn cht ca tc nhn gy nhim ngi ta th ng phn bit nhim v c, nhim hu c, n nhim ha h, nhim vi sinh vt c hc hay vt l ( nhim nhithoc do cc cht l lng khng tan), nhim phng x.

Nc ngm l ngun cungcp nc sinhhot ch yu nhiu quc gia v vngdnc trn th gii. Do vy, nhim nc ngm cnh hng rt ln n cht lng mi trng sng ca con ngi. Cc tc nhn gy nhim v suy thoinc ngm baogm:

- Nhim bn do tcng ca conngi, cc cht thi ca conngi v ng vt, cc cht thi sinhhot, cc cht thi ha hc v vic s dng phn bnhahc.

- Cc tc nhnt nhinnh nhim mn, nhim phn, hmlng Fe, Mn v

mt s kimloi khc. - Cc tc nhn nhnto nh nng kim loi nng cao, hmlng NO3-, NO2-, NH4+, PO4... vt tiuchun cho php, nhim bi vi sinhvt.

Tt c cc loi cht thi theothi gian ns ngm vongun nc, tcht dn v lm nhim ngun nc ngm. khng tngun nc ngm do tcng ca conngi b phnhy do cccht hu c kh phnhy, cc vikhun gy bnh, nht l

cc hacht c hi nh cc kimloi nng, d lng thuc tr su v khngngoi tr c cccht phngx.

Ngy nay, tnhtrng nhim v suy thoinc ngm ang ph bin cc khuvc th v cc thnh ph ln trn th gii. hn ch tc ng nhim v suythoinc ngm cn phi tin hnhng b cc cng tciu tra, thm d tr lng v cht lng ngun nc ngm, x l nc thi v chng nhim cc ngun nc mt, quantrc thng xuyntr lng v cht lng nc ngm.

1.2.2.1. Cc tc nhn v thng s nhim ha l ngun n c.a) Mu sc.


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Mu sc ca nc c gy bi cc hp cht hu c, cc hp cht keo st, nc thi cngnghip hoc do s pht trin ca rong,to. Thng nc h, ao c

mu cao. Nc ngm thng trongsut hoc muthp. b) Mi vv ca nc.

Nc c mi l do trongnc c cccht kh, ccmui khong ha tan, cchp cht hu c hay ccsn phm t phnhy vt cht gy ra.

Nc c th c mi bn, mit, mi tanh, mithi, mimc, mi clo, mi phenol

Ty theo thnh phn v hmlng cc mui khong ha tan mnc c v

mn, v chua,v cht,v ng c) Hm lng cn khng tan.

Hmlng cn ca nc ngm thng nh (30 50 mg/l),ch yu do ctmn c trongnc gy ra. Hmlng cn ca nc sng daong rt ln (20 5000mg/l) c khi lnti (30.000 mg/l) .Hmlng cn thayi theo ma, ma khnh, ma l ln. Cn c trongnc sng l do ccht ct, st, bn b dngnc xi ra mang theo v cccht hu c ngun gc ng thc vt mc nt ha tan trongnc.

d) Nhit .

Nhit ca nc c nh hng trc tip n qu trnhx l nc. s thayi nhit ca nc ty thuc vo tng loi ngun nc. Nhit ngun nc ngm thng n nh (17 270C).

e) dn in.

dn in ca nc tng theo hmlng ca cc cht khong ha tan trongnc v daong theonhit .

f) cng.

Dngnc c cng cao trong sinhhot s gy lng ph x phng do Canxiv Magie phn ng vi axit boto thnhhp cht kh tan.

Trongsn xut, nc cng cth to thnhlp cu cn cc lhi hoc gynh hng n cht lng sn phm.

g) pH.

S thayi pH ca n c lin quann s hin din cc ha cht axit hoc kim, pH ca n c ngm kh th p th ng daong t 3 6


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1.2.2.2. Cc tc nhn v thng s ha hc gy nhim ngun nc.

a) Kim loi nng.

Kimloi nng c Hg, Cd, Pb, As, Sb, Cr, Cu, Zn, Mn Chng l cc nguynt c hi vi con ngi v sinhvt. Hin tng nc b nhim kim loi nng thng gp trong cclu vc nc gn cc khu cngnghip, cc thnh ph ln v khuvc khai thc khongsn. nhim kimloi nng biu hin nng caoca cc kimloi nng trongnc.

Nguyn nhnch yu gy nhim kim loi nng l qu trnh vo mitrng nc nc thi cngnghip v nc thi c hi khngx l hoc x l khngt yucu. nhim nc bi kimloi nng c tcng tiucc ti mitrng sng ca sinhvt v conngi. Kim loi nng tch ly theochui thc n thmnhp v c th ngi. Nc mt b nhim s lan truyn cccht nhim vonc ngm, vot vcc thnh phn mi trng lin quan khc. hn ch nhim nc, cn phi tng cng bin phpx l nc thi cngnghip.

b) Cc hp cht Nit.

NH4+, NO3-, NO2- Do qu trnh phnhy cht hu c , do s dng rng ricc loi phn bn. Ngoi ra docu trca tng lmnc thng nhim Nitrat.

- Nhim bn do Nitrat trong n c r t c hi cho sc khe, n c th gy bnhmethemoglobin huyt tr em v m nui con nh.

- Nitrit khi i vo c th c kh nng kt h p v i thnh phn vn chuyn oxitrong mu l hemoglobin n c th thiu oxi gy nn kh th .

- Amonium c trong n c c th chuyn ha thnh nitrat hoc nitrit v vy s c mt ca n trong n c ngm cng nh h ng t i sc khe con ng i.

c) Cc hp cht photpho.

Thng gp photphat (PO43-), khng thuc loi ha cht c i vi conngi, nhng s tn ti trongnc cao lmcn tr qu trnhx l, c bit l hot ng ca b lng.

d) Cc hp cht silic.- pH < 8 : H2SiO3

- pH = 8 11: HSiO3-

- pH > 11 : SiO32-


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Trongnc cp cho ni hi p lc, s tn ti hp cht silic rt nguyhim dosilicatng li trn thnhni, thnhng, lm gim kh nng truyn nhit v gytt

ng. e) Clorua

Cl- cao gy nn cc bnh v thn, nc cha nhiu cht clorua gy xmthc i vi b tng.

f) Sunfat

Nng SO42- > 400 mg/l gymt nc trongc th v lm thorut. SO42- gy xmthc b tng.

g) Florua Nc ngm t nhng vngt cha cn apatit, alkalit, granit,thng c

hmlng florua caon 10 mg/l. Trongnc thin nhin florua bn v khngloi b c bng phng php thngthng.

Nu nng florua:

- 0,5 1,0 mg/l c tcdng bo v menrng - > 4 mg/l gyen rng v hy hoi rng vnh vin

h) St. Nc ngm st thng tn ti di dng Fe2+ kt hp vi SO42-, CO32-, Cl-

di dng keo ca axit humichoc keo silic cth cha st vi nng Fe2+ 400mg/l.

CFe2+ > 0,5 mg/l lm chonc c mi tanh, vngqun o, lmhng sn phm ca ngnhdt, giy, phimnh, hp. Cn st kt ta c th lm tc hoc gim kh nng vn chuyn ca ng dn nc.

i) Mangan.

Nc ngm c nng Mn2+ thng < 5 mg/l. Nu CMn2+ >0,1 mg/l gytr ngi tng t st.

j) Nc b nhim vi sinh vt.

Sinhvt c mt trong mitrng nc nhiu dng khc nhau. Bncnh ccsinhvt c ch, cnhiu nhm sinhvt gy bnh hoc truyn bnh chongi v sinhvt. Trongs ny, ng ch l ccloi vi khun, siu vikhun v k sinh trng gy


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bnh nh cc loi k sinh trng bnh t, l, thng hn,st rt, siu vikhun vim ganB, siu vikhun vim no Nht Bn, giun, tr ng giun

Ngun gy nhim sinhhc cho mitrng nc ch yu l phn rc,nc thi sinhhot, xccht sinhvt, nc thi cc bnh vin

k) Nc b nhim bi thuc bo v thc vt v phn bn ha hc

Trong qu trnhs dng thuc bo v thc vt v phn bn hahc ti cc vngnngnghip thm canh,mt lng ng k thuc v phn khngc cy trng tip nhn. Chngs lan truyn v tchly trongt, nc v ccsn phm nngnghip di dng d lng phn bn vthuc bo v thc vt - theo thi gian, s lm suythoicht lng mi trng khuvc canh tc nngnghip nh ph dng t, ngm vonc ngm, nhim t, nc, gim tnha dng sinhhc ca khuvc nng thn,suygim cc loi thinch, tng kh nng chng chu ca su bnh i vi thuc bo v thc vt.

1.3. CC CH TIU V THNG S NH GI CHT LNG NC.1.3.1. Cc ch tiu vt l.

a) Nhit : (0C) xcnh bng nhit k. b) mu: n v: platin coban (PtCo)

Nc thin nhinthng c mu < 200 PtCo. mu biu kin do cccht l lng trongnc, c th loi b bng phng phplc.

muthc do cccht ha tanto nn phi dng cc bin php ha lkt hp.

c) c. n v: SiO2/l, NTU FTU.

N c cp thng c c khng v t qu 5NTU

d) Mi, v: ngi, nm nh gi. e) nh tf) dn in: n v s/m (tng ng vi in tr 23,8 M/cm).

1.3.2. Cc thng s ha hc.a) pH.b) kim.

kim ton phn l tng hm l ng cc ion HCO3-, CO32-, OH-, anionca ccmui axit yu.

kim ph thuc vo pH v hm l ng kh CO2 t do trong n c.


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c) c ng.

n v o:

- c (0dH): 10dH = 10mg CaO/l n c- Php (0f): 10f = 10mg CaCO3/l n c- Anh (0e): 10e = 10mg CaCO3/0,7 l n c

- ng u (mgdt/l): 1mgdl/l = 2,80dH

cng < 50mg CaCO3/l: n c mm

50 150mg CaCO3/l: n c trung bnh

150 300mg CaCO3/l: n c cng

>300: n c r t cng

d) oxi ha.

e) Cc h p cht cha Nit (N)

f) Tng Photpho (P)

g) Cc h p cht Silic

h) Cht Cloruai) Sunfat

j) Florua

k) Kim loi nng: st, mangan, nhm

l) Ha cht BVTV v cht hot ng b mt

1.3.3. Cc ch tiu vi sinh

- Tng vi khun hiu kh- Tng vi khun k kh- E. coli

1.4. NNG GII H N CHO PHP CA CC CHT C HI C TRONG NGUN NC PHC V CP NC CHO SINH HOT.

1.4.1. Quy chun k thut Quc Gia v cht lng n c sinh hot (QCVN02:2009/BYT).

N c s dng trong sinh hot c th c cung c p t ngun n c ngm (ch yu)

hoc n c mt.


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N c sau khi x l cn m bo c an ton v sc khe ca ng i s dngv ph h p cng nhiu cng tt i v i tiu chun quc t. V c bn, n c c p cho

sinh hot khng c mi v l, khng c vi sinh vt gy bnh, nng cc cht c hi phi nm trong gi i hn quy nh, cc thng s c th c quy nh trong bng sau.

B ng 1-3:Quy chu n k tht qu c gia v ch t lng n c sinh ho t (QCVN 02:2009/BYT)

STT Tn ch tiu n v tnh

Gi i hn ti acho php Phng php

th

M c

gimstI II

1 Mu sc TCU 15 15

TCVN 6185-1996 (ISO 7887

1985) hocSMEWW 2120

A

2 Mi v -Khngc miv l

Khngc miv l

Cm quan hocSMEWW 2150B

v 2160BA

3 c NTU 5 5

TCVN 6184-1996 (ISO 7027-

1990) hocSMEWW 2130B

A

4 Clo d mg/lTrongkhong

0,3- 0,5

-SMEWW 4500Cl hoc US EPA

300.1

A

5 pH -Trongkhong6,0-8,5

Trongkhong6,0-8,5

TCVN6492:1999 hocSMEWW 4500-

H+

A

6 Hm l ngamoni mg/l 3 3SMEWW 4500-

NH3 C hoc

SMEWW 4500-

A


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NH3 D

7

Hm l ng st

tng s (Fe2 +Fe3+)

mg/l 0,5 0,5

TCVN6177:1996 (ISO

6332:1988) hocSMEWW 3500-

Fe

B

8 Ch s pecmaganat mg/l 4 4

TCVN6196:1996 hoc

ISO8467:1993(E)

A

9 cng theoCaCO3 mg/l 350 -

TCVN6224:1996 hoc

SMEWW 2340 CB

10 Hm l ngClorua mg/l 300 -

TCVN6194:1996 (ISO9297:1989) hocSMEWW 4500-

Cl- D

A

11 Hm l ngFlorua mg/l 1,5 -

TCVN6195:1996 (ISO10359-1-1992)hoc SMEWW

4500- F-B

12 Hm l ngasen tng s mg/l 0,01 0,05

TCVN

6626:2000 hoc3500- As B B

13 Coliform tngs Vi

khun/100ml 50 150

TCVN 6187-1,2:1996 (ISO9308-1,2:1990)hoc SMEWW

9222

A


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(ISO 12020 :1997)

8. Hmlng Amoni(*) mg/l 3

SMEWW 4500 - NH3 C hoc

SMEWW 4500 - NH3 D

B

9. Hm lng Antimon mg/l 0,005 US EPA 200.7 C

10.Hm lng Asen tngs mg/l 0,01

TCVN 6626:2000hoc SMEWW 3500-As B

B

11. Hm lng Bari mg/l 0,7 US EPA 200.7 C

12.

Hm lng Bo tnh

chungcho c Borat vAxit boric mg/l 0,3

TCVN 6635: 2000

(ISO 9390: 1990) hocSMEWW 3500 B C

13. Hm lng Cadimi mg/l 0,003

TCVN6197 - 1996(ISO 5961 - 1994)hoc SMEWW 3500Cd

C

14. Hm lng Clorua(*) mg/l 250300(**)

TCVN6194 - 1996(ISO 9297 - 1989)hocSMEWW 4500 -Cl- D

A

15.Hm lng Crom tngs mg/l 0,05

TCVN 6222 - 1996(ISO 9174 - 1990)hoc SMEWW 3500-Cr -

C

16.Hm lng ng tngs(*) mg/l 1

TCVN 6193 - 1996(ISO 8288 - 1986)hoc SMEWW 3500-Cu

C

17. Hm lng Xianua mg/l 0,07

TCVN 6181 - 1996(ISO 6703/1 - 1984)hoc SMEWW 4500-CN-

C

18. Hm lng Florua mg/l 1,5

TCVN 6195 - 1996(ISO10359 - 1 - 1992)hoc SMEWW 4500-F-

B


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19.Hm lng Hydrosunfur (*) mg/l 0,05 SMEWW 4500 - S

2- B

20.

Hm lng St tng s(Fe2+ + Fe3+)(*) mg/l 0,3

TCVN 6177 - 1996(ISO 6332 - 1988)hoc SMEWW 3500-Fe

A

21. Hm lng Ch mg/l 0,01TCVN 6193 - 1996(ISO 8286 - 1986)SMEWW 3500 - Pb A

B

22.Hm lng Mangantng s mg/l 0,3

TCVN 6002 - 1995(ISO 6333 - 1986) A

23. Hm lng Thu ngntng s mg/l 0,001TCVN 5991 - 1995(ISO 5666/1-1983 -ISO 5666/3 -1983) B

24. Hm lng Molybden mg/l 0,07 US EPA 200.7 C

25. Hm lng Niken mg/l 0,02TCVN 6180 -1996(ISO8288 -1986)SMEWW 3500 Ni

C

26. Hm lng Nitrat mg/l 50 TCVN 6180 - 1996(ISO 7890 -1988) A

27. Hm lng Nitrit mg/l 3 TCVN 6178 - 1996(ISO 6777-1984) A

28. Hm lng Selen mg/l 0,01 TCVN 6183-1996(ISO 9964-1-1993) C

29. Hm lng Natri mg/l 200 TCVN 6196 - 1996(ISO 9964/1 - 1993) B

30. Hm lng Sunpht (*) mg/l 250 TCVN 6200 - 1996(ISO9280 - 1990) A

31. Hm lng Km(*) mg/l 3 TCVN 6193 - 1996(ISO8288 - 1989) C

32. Ch s Pecmanganat mg/l 2TCVN 6186:1996hoc ISO 8467:1993(E)

A

II. Hm lng ca cc cht hu c a. Nhm Alkan clo ho33. Cacbontetraclorua g/l 2 US EPA 524.2 C


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58. Aldicarb g/l 10 US EPA 531.2 C59. Aldrin/Dieldrin g/l 0,03 US EPA 525.2 C60. Atrazine g/l 2 US EPA 525.2 C61. Bentazone g/l 30 US EPA 515.4 C62. Carbofuran g/l 5 US EPA 531.2 C63. Clodane g/l 0,2 US EPA 525.2 C64. Clorotoluron g/l 30 US EPA 525.2 C

65. DDT g/l 2SMEWW 6410B,hoc SMEWW 6630C

C

66. 1,2 - Dibromo - 3Cloropropan g/l 1 US EPA 524.2 C

67. 2,4 - D g/l 30 US EPA 515.4 C68. 1,2 - Dicloropropan g/l 20 US EPA 524.2 C69. 1,3 - Dichloropropen g/l 20 US EPA 524.2 C70. Heptaclo v heptaclo

epoxit g/l 0,03SMEWW 6440C C

71. Hexaclorobenzen g/l 1 US EPA 8270 - D C72. Isoproturon g/l 9 US EPA 525.2 C73. Lindane g/l 2 US EPA 8270 - D C74. MCPA g/l 2 US EPA 555 C75. Methoxychlor g/l 20 US EPA 525.2 C76. Methachlor g/l 10 US EPA 524.2 C77. Molinate g/l 6 US EPA 525.2 C

78. Pendimetalin g/l 20 US EPA 507, USEPA 8091 C

79. Pentaclorophenol g/l 9 US EPA 525.2 C80. Permethrin g/l 20 US EPA 1699 C81. Propanil g/l 20 US EPA 532 C82. Simazine g/l 20 US EPA 525.2 C83. Trifuralin g/l 20 US EPA 525.2 C


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84. 2,4 DB g/l 90 US EPA 515.4 C85. Dichloprop g/l 100 US EPA 515.4 C86. Fenoprop g/l 9 US EPA 515.4 C87. Mecoprop g/l 10 US EPA 555 C88. 2,4,5 - T g/l 9 US EPA 555 CIV. Ho cht kh trng v sn phm ph 89. Monocloramin g/l 3 SMEWW 4500 - Cl G B

90. Clo d mg/lTrongkhong0,3 - 0,5

SMEWW 4500Clhoc US EPA 300.1 A

91. Bromat g/l 25 US EPA 300.1 C92. Clorit g/l 200 SMEWW 4500 Clhoc US EPA 300.1 C

93. 2,4,6 Triclorophenol g/l 200 SMEWW 6200 hocUS EPA 8270 - D C

94. Focmaldehyt g/l 900 SMEWW 6252 hocUS EPA 556 C

95. Bromofoc g/l 100 SMEWW 6200 hoc

US EPA 524.2C

96. Dibromoclorometan g/l 100 SMEWW 6200 hocUS EPA 524.2 C

97. Bromodiclorometan g/l 60 SMEWW 6200 hocUS EPA 524.2 C

98. Clorofoc g/l 200 SMEWW 6200 C

99. Axit dicloroaxetic g/l 50 SMEWW 6251 hocUS EPA 552.2 C

100. Axit tricloroaxetic g/l 100 SMEWW 6251 hocUS EPA 552.2 C

101.Cloral hydrat(tricloroaxetaldehyt) g/l 10

SMEWW 6252 hocUS EPA 8260 - B C

102. Dicloroaxetonitril g/l 90 SMEWW 6251 hocUS EPA 551.1 C

103. Dibromoaxetonitril g/l 100 SMEWW 6251 hocUS EPA 551.1 C


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8 Hmlng asen Mg/l Khng phthin

9 Hmlng mangan Mg/l 3

10 Hmlng Florua Mg/l 1

11 Hmlng clorua Mg/l 120

12 Tng coliform Vikhun/100ml 300

13 Tng Ecoli Vikhun/100ml 50


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CHNG II: CCPHNG PHP X L NC

2.1. CC CNG TRNH THU NC

Cng trnh thu n c c nhim v thu n c t ngun nc. Cng trnh thu n cmt c cc dng k t h p hoc phn ly, thu n c st b bng ca thu hoc thu n cgia dng bng ng t chy, xiphng. Cng trnh thu n c ngm th ng l gingkhoan, thu n c t ngun n c ngm mch su c p. Chn v tr cng trnh thu n cda trn c s m bo lu l ng, cht lng, n nh, tui th cng trnh v thuntin cho vic bo v v sinh ngun n c.2.2. CC CNG TRNH V N CHUYN NC

Tr m bm c p I c nhim v a n c th t cng trnh thu ln tr m x l n c.Tr m bm cp I thng t ring bit bn ngoi tr m x l nc, c tr ng h p lyn c t xa, khong cch n tr m x l c th t i vi kilomet thm ch hng chckilomet. Tr ng h p s dng ngun n c mt, tr m bm c p I c th k t h p v i cngtrnh thu hoc xy dng ring bit. Cng trnh thu n c sng hoc h c th dng ca

thu vng t chy, ng xiphng hoc c bit c tr ng h p ch dng ca thu vng t chy n tr m x l khi mc n c ngun nc cao hn cao tr m x l. Khi s dng n c ngm, tr m bm cp I thng l cc my bm chm c p lc cao, bmn c t ging khoan n tr m x l.

2.3.CC BIN PHP X L NC

X l nc l qu trnh lm thay i thnh phn, tnh cht nc t nhin theoyu cu ca i tng s dng ph thuc vo thnh phn, tnh cht ca nc ngunyu cu cht lng ca nc, ca i tng s dng.

Bin php c hc: S dng c hc gi li cc cn khng tan trong nc. Cccng trnh: song chn rc, li chn rc, b lng, b lc.

Phng php hal: Dng cc cht ha hc cho vo nc x l nc nh:keo t bng phn, kh trng bng Clo, kim ha nc bng vi, dng ha cht dit to (CuSO4, Na2SO4).

Bin php l hc: kh trng nc bng tia t ngoi, sng siu m, in phnnc kh mui


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Trong 3 bin php x l trn, bin php x l c hc l bin php x l nc c bn nht. C th p dng bin php x l c hc mt cch c lp hoc kt hvi bin php ha hc v l hc nng cao hiu qu x l cng nh rt ngnthi gian x l.

2.3.1. X l nc bng phng php c hc.

2.3.1.1. H cha v lng s b

Chc nng ca h cha v lng s b nc th (n c mt) l: to iu kin thunl i cho cc qu trnh t lm sch nh: lng b t cn l lng, gim l ng vi trng do tcng ca cc iu kin mi tr ng, thc hin cc phn ng oxy ha do tc dng caoxy ha tan trong n c, v lm nhim v iu ha lu l ng gia dng chy t ngunnc vo v lu l ng tiu th do tr m bm nc th bm c p cho nh my x ln c.

2.3.1.2. Song chn rc v l i chn rc

Song chn v l i chn t ca dn n c vo cng trnh thu lm nhim v loitr vt ni, vt tri l lng trong dng nc bo v cc thit b v nng cao hiuqu lm sch ca cc cng trnh x l. Vt ni v vt l lng trong n c c th c kchth c nh nh que tm ni, hoc nhnh cy non khi i qua my bm vo cc cngtrnh x l c th b tn nh hoc thi r a lm tng hm l ng cn v mu can c. Song chn rc c cu to gm cc thanh thp tit din trn c 8 hoc 10, hoctit din hnh ch nht kch thc 6 x 50 mm t song song v i nhau v hn vo khungthp. Khong cch gia cc thanh thp t 40 50 mm. Vn tc n c chy qua songchn khong 0,4 0,8 m/s. Song chn rc c nng th nh rng r c hoc t i quaytay b tr trong ngn qun l. Hnh dng song chc rc c th l hnh ch nht, hnhvung hoc hnh trn.

2.3.1.3. lng

B lng c nhim v lm sch s b trc khi a n c vo b lc hon thnhqu trnh lm trong n c. Theo chiu dng chy, b lng c phn thnh: b lngngang, b lng ng, b lng l p mng v b lng trong c l p cn l lng. Trong b lng ngang, dng n c thi chy theo phng ngang qua b v i vn tc khng ln hn16,3 mm/s. Cc b lng ngang thng c s dng khi lu lng n c ln hn 3.000m3/ngy. i v i b lng ng, n c chuyn ng theo phng thng ng t d iln n vch trn v i vn tc 0,3-0,5 mm/s. Hiu sut lng ca b lng ng th ng


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thp hn b lng ngang t 10 n 20%. B lng l p mng c cu to ging nh b lng ngang thng thng, nhng khc v i b lng ngang l trong vng lng ca b

lng l p mng c t thm cc bn vch ngn bng thp khng g hoc bng nha.Cc bn vch ngn ny nghing mt gc 450 600 so v i mt phng nm ngang vsong song v i nhau. Do c cu to thm cc bn vch ngn nghing, nn b lng l pmng c hiu sut cao hn so v i b lng ngang. Din tch b lng l p mng gim5,26 ln so v i b lng ngang thun ty. B lng trong c l p cn l lng c u iml khng cn xy dng b phn ng, b i v qu trnh phn ng v to bng k t ta xyra trong iu kin keo t ti p xc, ngay trong l p cn l lng ca b lng. Hiu qu x l cao hn cc b lng khc v tn t din tch xy dng hn. Tuy nhin, b lng trongc cu to phc t p, k thut vn hnh cao. Vn tc nc i t d i ln vng lngnh hn hoc bng 0,85 mm/s v thi gian lu n c khong 1,5 2 gi .

2.3.1.4. Lc

B lc c dng lc mt phn hay ton b cn bn c trong n c ty thucvo yu cu i v i cht lng n c ca cc i tng dng n c. Qu trnh lc n cl cho nc i qua l p vt liu lc v i mt chiu dy nht nh gi li trn b mt hoc gia cc khe h ca l p vt liu lc cc ht cn v vi trng c trong n c.Sau mt th i gian lm vic, l p vt liu lc b kht li, lm tng tn tht p lc, tc

lc gim dn. khi phc li kh nng lm vic ca b lc, phi thi r a b lc bngn c hoc gi, n c k t hp loi b cn bn ra khi l p vt liu lc. Tc lc llng nc c lc qua mt n v din tch ca b lc trong mt n v th i gian(m3/h). Chu k lc l khong th i gian gia hai ln r a b lc T(h). thc hin qutrnh lc n c c th s dng b lc n c c nguyn tc hot ng, cu to l p vt liulc v thng s vn hnh khc nhau :theo c tnh nh lc lin tc, lc gin on.Theo dng ca qu trnh nh lm c v lc trong. Theo p sut ca qu trnh lc nhlc chn khng v lc p lc hay lc d i p sut thy tnh ca ct cht lng Trongcc h thng x l n c c cng sut l n khng cn s dng cc thit b lc c p sutcao m dng cc b lc c cc l p vt liu lc dng ht. Vt liu lc c th s dng lct thch anh, than cc hoc si nghin, thm ch c than nu hoc than g. Vic lachn vt liu lc ph thuc vo ngun nc u vo v iu kin a phng. Qutrnh lc xy ra theo nhng c ch sau:

- Sng lc tch hon ton cc vt r n bng nguyn l c hc.- Lng tr ng lc.- Gi ht r n theo qun tnh.- H p ph ha hc, h p ph vt l.


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- Qu trnh dnh bm.- Qu trnh lng to bng.

2.3.2. X l n c bng phng php ha l. 2.3.2.1. Lm thong.

Bn cht ca qu trnh lm thong l ha tan oxy t khng kh vo nc oxyha st ha tr II, mangan ha tr II thnh st ha tr III, mangan ha tr IV to thnhcc h p cht hydroxyl st ha tr III v hydroxyl mangan ha tr IV Mn(OH)4 k t tad lng ng kh ra khi n c bng lng, lc. Lm thong kh CO2, H2S ctrong nc, lm tng pH ca n c, to iu kin thun li v y nhanh qu trnh oxyha v thy phn st v mangan, nng cao cng sut ca cc cng trnh lng v lc

trong quy trnh kh st v mangan. Qu trnh lm thong lm tng hm l ng oxyha tan trong n c, nng cao th oxy ha kh ca nc thc hin d dng cc qutrnh oxy ha cc cht hu c trong qu trnh kh mi v mi ca n c. C hai phng php lm thong: a nc vo trong khng kh: cho n c phun thnh tiahay thnh mng mng chy trong khng kh cc dn lm thong t nhin, hay chon c phun thnh tia v mng mng trong cc thng kn r i thi khng kh vo thngnh cc dn lm thong c ng bc. a khng kh vo n c: dn v phn phikhng kh nn thnh cc bt nh theo dn phn phi t y b cha n c, cc bt

kh ni ln, nc c lm thong. Hn hp hai phng php trn: lm thong bngmng trn nhiu bc v phun trn mt n c.


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Hnh 2-1: Qu trnh lm thong

2.3.2.2. Clo ha s b.

Clo ha s b l qu trnh cho clo vo nc tr c b lng v b lc. Clo ha s b c tc dng tng th i gian kh trng khi ngun n c nhim bn nng, oxi ha stha tan dng h p cht hu c, oxy ha mangan ha tan to thnh cc k t tatng ng, oxy ha cc cht hu c kh mu, ph hy t bo ca cc vi sinh sn racht nhy nh t trn mt b lc.

2.3.2.3. Kh trng n cKh trng n c l khu bt buc trong qu trnh x l nc n ung sinh hot.

Trong n c thin nhin cha r t nhiu vi sinh vt v kh trng. Sau cc qu trnh x l c hc, nht l n c sau khi qua b lc, phn ln cc vi trng b gi li. Song tiu dit hon ton cc vi trng gy bnh, cn phi tin hnh kh trng n c. Hinnay c nhiu bin php kh trng c hiu qu nh: kh trng bng cc cht oxy hamnh, cc tia vt l, siu m, phng php nhit, ion kim loi nng,

a) Kh trng n c b ng Clo vcc h p ch t c a CloClo l mt cht oxy ha mnh bt c dng no. Khi Clo tc dng vi n c to

thnh axit hypoclorit (HOCl) c tc dng dit trng mnh. Khi cho Clo vo n c,cht dit trng s khuch tn xuyn qua v t bo vi sinh vt v gy phn ng v imen bn trong ca t bo, lm ph hoi qu trnh trao i cht dn n vi sinh vt b tiu dit.

Khi cho Clo vo n c, phnng din ra nh sau:

Cl2 + H2O HOCl + HCl


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Hoc c th dng phng trnh phn ly:

Cl2 + H2O H+ + OCl- + Cl-

Khi s dng Clorua vi, phnng din ra nh sau:

Ca(OCl)2 + H2O CaO + 2HOCl +2HOCl 2H+ + 2OCl-

b) Kh tr ng b ng ozon.Ozone l mt cht kh c mu nh tmt ha tan trong n c v r t c hi i

vi con ngi. trong n c, ozone phn hy r t nhanh thnh oxy phn t v nguynt. Ozone c tnh hot ha mnh hn Clo, nn kh nng dit trng mnh hn Clo rtnhiu ln. Th i gian ti p xc r t ngn do din tch b mt thit b gim, khng gy

mi v kh chu trong n c k c khi trong n c c cha phenol.c) Kh tr ng b ng phng php nht.

y l phng php kh trng c truyn. un si n c nhit 1000C c th tiu dit phn l n cc vi khun c tr ong n c. Ch tr nhm vi khun khi g p nhit cao s chuyn sang dng bo t vng chc. Tuy nhin, nhm vi khun ny chim t l r t nh. Phng php un si nc tuy n gin, nhng tn nhin liu v cng k nh,nn ch dng trong quy m gia nh.

d) Kh tr ng b ng tia c c tm (U V)Tia cc tm l tia bc x in t c b c sng khong 4 400 nm, c tc dng

dit trng r t mnh. Dng cc n bc x t ngoi, t trong dng chy ca n c.Cc tia cc tm pht ra s tc dng ln cc phn t protit ca t bo vi sinh vt, phv cu trc v mt kh nng trao i cht, v th chng s b tiu dit. Hiu qu kh trng ch t c trit khi trong n c khng c cc cht hu c v cn l lng.St trng bng tia cc tm khng lm thay i mi, v ca n c

e) Kh tr ng b ng siu mDng siu m vi cng tc dng khng nh hn 2W/cm2 trong khong th i

gian trn 5 pht c kh nng tiu dit ton b vi sinh vt trong n c.

f) Kh tr ng b ng ion b c.Ion bc c th tiu dit phn l n vi trng c trong n c. Vi hm l ng 2 10

ion g/l c tc dng dit trng. Tuy nhin, hn ch ca phng php ny l: nutrong nc c mu cao, c cht hu c, c nhiu loi mui,th ion bc khng pht huy c kh nng dit trng


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trong nc, thc y qu trnh tch in tr li i vi cc ht keo, lm tng th inng zeta v v vy hiu qu ca qu trnh keo t s gim i.

Qu trnh keo t do c ch hp ph- bc cu Trng hp ny xy ra khi dng ha cht keo t l cc hp cht polime, khi cc

on polime hp ph trn b mt ht keo, do cu trc mch di ca chng s to ra cni gia cc ht keo, hnh thnh bng keo t c kch thc ln hn lm tng tc lng ca cc ht keo.

Kh nng to bng keo t nh c ch ny ph thuc vo nhm polime v ht keotrong nc, ph thuc vo qu trnh hp ph cc polime ln b mt ht keo v slng cc polime c trong nc.

Tng t nh c ch hp ph- trung ha in tch, lng polime a vo cngch cn mt gi tr nht nh t c hiu qu ti u, vt qua gii hn s ts cn bng mi trong h keo.

Trong lng phn t ca cc polime lin quan n kh nng ha tan ca chng.Khi trng lng phn t tng, kh nng ha tan ca chng km i, dung dch c nht cao hn, liu lng dng ti u s cao hn v lng bng cn to ra v vy cnln hn, lm rt ngn qu trnh lng.

Gi tr pH ca mi trng khng gy nh hng lm n cc polime khng intch, nhng i vi anion pH cao hoc plime cation pH thp s gy nh hng qu trnh ion ha ca chng, dn n nh hng ti qu trnh to bng keo.

Qu trnh keo t hp ph trong qu trnh lng

Cc ion kim loi ha tr cao c s dng trong qu trnh keo t nh: Al3+, Fe3+ to ra trong nc cc sn phm thy phn khc nhau l cc hiroxit mang in nh:

Fe2(OH)24+, Fe(OH)4-, Al3(OH)4-, Al3(OH)45+, Al13(OH)345+, Al7(OH)174+ Nhng

mt gi tr pH nht nh no th cc phn t hiroxit nhm Al(OH)3 hoc stFe(OH)3 c hnh thnh v lp tc lng xung do trng lc ca chng. Trong qutrnh lng chng s ko theo cc bng keo v tp cht trong h huyn ph nh cc keokhc, cc cn bn, cc cht hu c tn ti trng thi ha tan hoc l lng trongnc. C ch ny khng ph thuc vo qu trnh to bng t nn khng c s ti nnh tr li nh cc c ch khc.

c) Cc phng php keo t. Trong cng ngh x l nc bng keo t, c th x dng mt s phng php:


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Keo t dng cc cht in li n gin. Keo t dng h keo ngc du. Keo t dng cc cht polime.

Keo t dng cc cht in li n gin

Bn cht ca qu trnh ny l a vo n c cc cht in li n gin, mang intch ng c du v i h keo trong n c. Khi nng ion ng c du tng ln, th s iont l p khuch tn c chuyn vo lp in tch kp cng tng ln, lm gim lc ytnh in gia cc ht. ng th i chuyn ng Brown s gip cho cc ht ny c chi va chm v k t dnh li v i nhau, to nn cc bng cn ln hn. Khi kch th cca cc bng cn tng n mc nht nh th chuyn ng Brown s ht tc dng vchng s lng dn xung y, tit kim th i gian, c th tng c ng s khuy tr n cc ht cn c nhiu c hi ti p xc vi nhau hn.

Keo t b ng h keo ng c d u

Ha cht thng c s dng trong tr ng hp ny th ng l mui nhm hocmui st (th ng gi l phn), c a vo nc d i dng dung dch ha tan. Saukhi thy phn, chng tr thnh phn t mang in tch dng c kh nng trung hacc loi keo mang in tch m trong n c.

Trong dung dch, cc mui nhm (hoc st) c phn li, tr ng thi tn ti cacc h p cht ca chng ph thuc vo gi tr pH. Khi pH 6 (v i nhm) hoc pH 5(v i st), chng tn ti trong cc hiroxit (M(OH)3) k t ta lng xung, khi 3


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- Loi bng cn ny chim u th v c tnh cht quyt nh n hiu qu caqu trnh keo t.

Mt s loi phn nhm hoc phn st c s dng trong qu trnh ny l:Al2(SO4)3.14H2O; AlCl3.6H2O; [Al(OH)1,5(SO4)0,125Cl1,25]n; NaAlO2; Fe2(SO4)3.8H2O;FeSO4.7H2O; FeCl3; AlFe(SO4)3.nH2O: FeClSO4

Keo t (hoc tng c ng qu trnh keo t ) b ng cc h p ch t cao phn t

Mt s h p cht cao phn t c ngun gc vc hoc hu c c th dng tngc ng cho qu trnh keo t, tc l s dng cng phn nhm hoc phn st, chng ctc dng lm cho qu trnh keo t din ra nhanh hn v to ra bng keo c kch th cln hn hoc dng nh mt cht keo t trong mt vi tr ng h p.

C ch ca qu trnh ny khc vi c ch ca qu trnh keo t bng cht in liv qu trnh keo t bng h keo ng c du v chng din ra cc tng tc ha hc. Dokch th c l n v di nn chng lin k t v i cc ht cn trong nc d i dng lin k tchui, tr ng l ng ca chng v vy s tng ln v qu trnh lng bng cn din ra.y l kiu lin k t r t thun l i cho qu trnh hnh thnh v lng bng cn, tuy nhinn t c s dng trong k thut x l n c n c ta hin nay

Cc giai on ca qu trnh keo t .

Qu trnh keo t cc cht trong nc th ng tr i qua cc giai on:- Giai on ha tr n ha cht vo trong n c.- Giai on phn hy cht keo t ng th i ph v tr ng thin nh ca h keo.- Giai an hnh thnh bng cn ( c th tch ra thnh 2 giai on nh: giai on

hnh thnh bng keo nh nh chuyn ng nhit v giai on hnh thnh cc bng keo c kch th c ln tch ra khi n c.

Ba giai on trn xy ra gn nh ng th i v lin tc. khi h keo trong nc b cc cht keo ph v tr ng thin nh th tc to bng hon ton ph thuc vochuyn ng to ra s va chm gia cc ht keo vi nhau. Di tc ng ca chuynng nhit, cc ht cn b va chm v k t dnh v i nhau, to thnh cc bng cn ckch th c l n dn ln t i khi khng th tham gia vo chuyn ng nhit na. tnghiu qu cho qu trnh th cn to iu kin cho cc bng cn ti p tc chuyn ng va chm vo nhau, y l giai on quyt nh hiu qu ca ton b qu trnh keo t.

2.4.2. Cc loi thit b nh l ng, khuy tr n v b phnng.

Qu trnh keo t cc cht phnng c thc hin trong mt s cc cng trnhv thit b ha tr n theo tng cng on nh sau:


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Chu n b dung d ch v nh l ng ha ch t : Thng (b) ha tr n ha cht,thng tiu th, thit b nh liu l ng cht phnng.

Ha tr n ha ch t vi n c: ng tr n, b tr n Qu trnh t o bng keo kch th c l n: Ngn phnng, b phnng

a) Thi t b chu n ha ch t (phn)C nhim v ha tan phn cc v lng cc cn bn. Nng dung dch trong b

ha tr n thng cao, nhng khng v t qu mc bo ha. Qu trnh ha tan phnth ng ko di trong khong t 2 3 gi , c th dng bin php nn kh, my khuyhoc bm tun hon trong khong 2 3 gi r i a sang b tiu th.

b) Thi t b nh l ng ha ch tL thit b c th iu chnh c l ng ha cht a vo n c theo yu cu.

Theo chc nng s dng. c th chia thit b nh l ng thnh 2 loi : nh liu l ngthay i ( theo t l n c x l hoc tnh cht ca n c cn x l) v theo ch chyca dung dch ( nh liu l ng t chy a dung dch phn vo b tr n hoc nhliu l ng c p a dung dch phn vong p lc).

c) Thi t b ha tr n ch t ph n ng

Mc ch ca cng on ny nhm tr n ha cht v nc t n ng utrong th i gian ngn nht. C th da vo ng lc dng chy, nng l ng cung c pt bn ngoi hoc cc vt cn tr chuyn ng ca dng nc to nn s xo tr ncn thit.

Khu y tr n c hc

Bin php ha tr n c hc c thc hin nh nng l ng ca cnh khuy tora dng chuyn ng r i.

Tr n c hc c nhiu u in nh th i gian tr n ngn, c th t iu chnh c ng khuy tr n theo mun, nhng ng thi i hi phi c my khuy v cc thit b c kh khc i hi trnh qun l v vn hnh cao. Tr n c hc nn p dng cho ccnh my n c c mc c gi i ha, t ng ha cao v c cng sut l n.

Khu y tr n th y l c

Nguyn l ca qu trnh l dng cc vt cn gy nn s xo tr n gia ha cht vn c cn x l. Qu trnh tr n c th thc hin trongng dn, b tr n c vch ngnhoc b tr n ng.


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d) Cc lo i b ph n ng B phn ng t o bng keo dng nng l ng c kh

B phnng to bng keo dng nng lng c kh c thit k thnh nhiungn, mi ngn c chia thnh nhiu bung th ng c cc cnh bng nhau, ngn

cch bi cc vch hng dng theo phng thng ng. Dung tch b c thit k ph h p v i cng sut sao cho thi gian lu n c trong b 10 30 pht.

Qu trnh to bng keo din ra trong b nh s xo tr n bng cnh khuy. ycng l b phn chnh ca b. Cc cnh khuy th ng c dng bn phng, t ixng theo phng nm ngang hoc thng ng, din tch bn cnh khuy c thit k bng 15 20% din tch mt ct ngang ca b.

B phn ng t o bng keo bng nng l ng th y l c

Khc v i b phnng dng nng lng c kh, nng lng c dng trong b ny l nng lng c to ra do s chuyn ng ca dng n c trong thit b toiu kin trong qu trnh ti p xc, k t dnh gia cc ht keo v cn bn trong n c.Da vo cch cu to v vn hnh, c th chia thnh cc loi b sau: b phnngxoy, b phnng c vch ngn v b phnng c l p cn l lng.

Trong b phnng xoy: c 2 loi b phnng xoy hnh tr v b phnng

xoy hnh cn.2.5. KH ST TRONG NC NGM

2.5.1. Tr ng thi tn ti t nhin ca st trong ngun n c.

Trong n c ngm st th ng tn ti dng ion, st c ho tr 2 (Fe2+) l thnh phn ca cc mui ho tannh: Fe(HCO3)2; FeSO4hm l ng st c trong ccngun n c ngm th ng cao v phn b khng ng u trong cc l p tr m tch d it su. Nc c hm l ng st cao, lm cho n c co mi tanh v c mu vng, gynh h ng khng tt n cht lng nc n ung sinh hot v sn xut. Do , khim nc c hm l ng st cao hngi i hn cho php theo tiu chun th chng ta phitin hnh kh st.

Cc h p cht v c ca ion st ho tr II: FeS, Fe(OH)2, FeCO3, Fe(HCO3)2,FeSO4, v.v

Cc h p cht v c ca ion st ho tr III: Fe(OH)3, FeCl3 trong Fe(OH)3 l cht keo t, d dng lng ng trong cc b lng v b lc. V th cc h p cht vc ca st ho tan trong n c hon ton c th x l bng phng php l hc: lm

thong ly oxy ca khng kh oxi ho st ho tr II thnh st ho tr III v cho qu


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trnh thu phn, keo t Fe(OH)3 xy ra hon ton trong cc b lng, b lc ti p xc vcc b lc Cc phc cht v c ca ion st v i silicat, photphat FeSiO(OH)3 Cc phc

cht hu c ca ion st vi axit humic, funvic,Cc ion st ho tan Fe(OH)+

, Fe(OH)3 tn ti tu thuc vo gi tr th oxyi ho kh v pH ca mi tr ng. Cc loi phc chtv hn h p cc ion ho tan ca st khng th kh bng phng php l hc thngth ng, m phi k t h p v i phng php ho hc. Mun kh st dng ny phi chothm vo n c cc cht oxiho nh: Cl-, KMnO4, Ozon, ph v lin k t v oxy hoion st thnhion ho tr III hoc cho von c cc cht keo t FeCl3 , Al(SO4)3 v kimho c gi tr pH thch h p cho qu tr nh ng keo t cc loi keo st v phn xyra trit trong cc b lng, b lc ti p xc v b lc trong.

2.5.2. Cc phng php kh st trong x l n c2.5.2.1. Phng php oxi ha st

Nguyn l ca phng php ny l oxy ho (II) thnh st (III) v tch chng rakhi nc d i dng hiroxit st (III). Trong n c ngm, st (II) bicacbonat l mtmui khng bn, n d dng thu phn thnh st (II)hyroxyt theo phnng:

Fe(HCO)3)2 + 2H2O Fe(OH)2 + 2H2CO3

Nu trong n c c oxy ho tan, st (II) hiroxit s b oxy ho thnh st (III)

hiroxit theo phnng:4Fe(OH)2 + 2H2O + O2 4Fe(OH)3

St (III) hiroxit trong n c k t ta thnh bng cn mu vng v c th tch rakhi n c mt cch d dng nh qu trnh lng lc.

K t h p cc phn ng trn ta c phn ng chung ca qu trnh oxy ho st nhsau:

4Fe2+ + 8HCO3 + O2 + H2O 4Fe(OH)3 + 8H+ + 8HCO3-

N c ngm th ng khng cha oxi ho tan hoc c hm l ng oxi ho tan r tthp. tng nng oxi ho tan trong n c ngm, bin php n gin nht l lmthong. Hiu qu ca bc lm thong c xc nh theo nhu cu oxi cho qu trnhkh st.

2.5.2.2. Phng php kh st bng qu trnh oxi ha Lm thong n gin b m t l c


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N c cn kh st c lm thong bng dn phun ma ngay trn b mt lc.Chiu cao gin phun th ng ly cao khong 0,7m, l phun c ng knh t 5-7mm,

lu lng t i vo khong 10 m3

/m2

L ng xy ho tantrong n c sau khi lm thong nhit 250C ly bng 40% l ng xy ho tan bo ho ( 250C l ng oxi bo ho bng 8,1 mg/l).

Lm thong b ng gin ma t nhin N c cn lm thong c t i ln gin lm thong mt bc hay nhiu bc v i

cc sn r i x hoc tre g.Lu lng t i v chiu cao thp cng ly nh tr ng h ptrn. L ng xy ho tan sau lm thong bng 55% l ng oxi ho tan bo ho. Hml ng CO2 sau lm thong gim 50%.

Lm thong c ng b cCng c th dng thp lm thong c ng bc vi lu lng t i t 30 n 40

m3/h. L ng khng kh ti pxc ly t 4 n 6 m3 cho 1m3nc. L ng oxi ho tan saulm thong bng 70% hm l ng oxi ho tan bo ho.Hm l ng CO2 sau lm thonggim 75%.

2.5.2.3. Kh st bng ha cht.

Khi trong n c ngun c hm l ng t p cht hu c cao, cc cht hu c s tora dng keo bo v cc ion st, nh vy mun kh st phi ph v c mng hu c bo v bng tc dng ca cc cht xy ho mnh. i v i n c ngm, khi lm l ngst qu cao ng th i tn ti c H2S th l ng oxithu c nh lm thong khng oxi ho ht H2S v st, trong tr ng h p ny cn phi dng n ho cht kh st.

Bi n php kh s t b ng viKhi cho vi vo nc, pH ca nc tng ln. iu kin giu ion OH-, cc

ion Fe2+ thu phn nhanh chng thnh Fe(OH)2 v lng xung mt phn, th oxi hokh tiu chun ca h Fe(OH)2/Fe(OH)3 gim xung, do st (II) d dng chuynho thnh st (III). St (III) hyroxyt kt t thnh bng cn, lng trong b lng v cth d dng tch ra khi n c.Phng php ny c th p dng cho c n c mt vn c ngm. Nhc im ca phng php ny l phi dng n cc thit b pha ch cng k nh, qun l phc t p, cho nn th ng k t h p kh st v i qu trnh x l khcnhx ln nh n c bng kim, lm mm n c bng vi k t h p vi sa.

Bi n php kh s t b ng CloQu trnh kh st bng clo c thc hin nh phnng sau:


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2Fe(HCO3)2 + Cl2 + Ca(HCO3)2 + 6H2O 2Fe(OH)3CaCl2 + 6H+ + 6HCO3- Bi n php kh s t b ng Kali Permanganat (KM nO 4 )

Khi dng KMnO4 kh st, qu trnh xy ra r t nhanh v cn mangan (IV)hiroxit va c to thnh s l nhn t xc tc cho qu trnh kh. Phn ng xy ratheo phng trnh sau:

5Fe2+ + MnO4- + 8H+ 5Fe3+ + Mn2+ + 4H2O

Bin php kh st bng cch lc qua l p vt liu c bit

Cc vt liu c bit c kh nng xc tc, y nhanh qu trnh oxi ho kh Fe2+ thnh Fe3+ v gi li trong tng lc. Qu trnh din ra r t nhanh chng v c hiu qu

cao. Ct en l mt trong nhng cht c c tnh nh th. Bi n php kh s t b ng phng php trao i ion

Phng php trao i ion c s dng khi k t h p v i qu trnh kh cng. Khis dng thit b trao i ion kh st, n c ngm khng c ti p xc v i khng khv Fe3+ s lm gim kh nng trao i ca cc ion. Ch c hiu qu khi kh n c ngmc hm l ng st th p.

Bi n php kh s t b ng phng php vi sinh

Mt s loi vi sinh c kh nngoxi ho st trong iu kin m qu trnh oxiho ho hc xy ra r t khkhn. Chng ta cy cc mm khun st trong l p cy lcca b lc, thng qua hot ng ca cc vi khun st c loi ra khi nc. Th ngs dng thit b b lc chm kh st.

2.6. KH MANGAN TRONG NC NGM

Mangan th ng tn ti song song v i st dng ion Mn2+ trong n c ngm vdng keo hu c trong n c mt. Do vic kh mangan thng c tin hnh ngth i v i qu trnh kh st.

Mangan dng ha tan Mn2+ khi b oxi ha chuyn dn thnh Mn3+ v Mn4+ dng hiro kt ta:

2Mn(HCO3)2 + O2 + 6H2O 2Mn(OH)4 + 4H+ + 4HCO3-

Qu trnh kh mangan ph thuc vo pH ca n c. Thc nghim cho thy nu pH < 8 v khng c cht k t xc tc th qu trnh oxi ha Mn2+ r t chm. pH ti u8,5 9.

Tng t nh khu kh st qu trnh kh mangan cng tng t.


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2.6.1 Phng php kh mangan bng lm thong. Lm thong t nhin hoc lm thong c ng bc - lng ti p xc - lc 1 l p vt

liu lc.p dng khi hm l ng mangan trong n c nh v tn ti d i dng Mn2+ ha

tan. Vt liu lc dng ct thch anh dy 1,2 1,5m. Lm thong t nhin hoc lm thong c ng bc - lng ti p xc - lc 1 hay 2l p vt liu lc.

p dng khi n c ngun c hm l ng mangan cao.

Mt l p vt liu l ct en dy 1,5m; hoc 2 l p vt liu lc l l p vt liu lc

Mt l p vt liu l ct en dy 1,5m; hoc 2 l p vt liu lc l than Antraxit vct dy 1,5m.

Lm thong c ng bc - lng ti p xc - lc 2 bc

Kh st c thc hin lm thong lng ti p xc lc. Sau nng pH ln8 lm thong lc b lc bc 2 kh mangan.

Phng php ny tn km nhng c hiu qu x ln nh.

2.6.2. Phng php dng ha cht

S dng cc cht c tnh oxi ha mnh nh ozon, Clo, kali permanganat

Clo oxi ha Mn2+ pH = 7 trong th i gian t = 60 90 pht

ClO2 v ozon oxi ha Mn2+ cn mt l ng 1,35 mg ClO2 hay 1,45 mg O3.

KMnO4 oxi ha Mn2+ mi dng tn ti k c keo hu c to thnhMn(OH)4.

2.6.3. Phng php sinh hc.

Cy 1 loi vi sinh vt c kh nng h p th mangan trong qu trnh sinh tr ngtrn b mt vt liu lc. Xc vi sinh vt s to thnh l p mng oxit mangan trn b mtvt liu lc c tc dng xc tc qu trnh kh mangan.


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CHNG III: XUT PHNG N X L V TNH TON CNG TRNH

N V

3.1. C S L A CH N CNG NGH.

B ng 3-1: B ng thng s nc u vo

STT Ccch tiu n v Gi tr

1 Musc PtCo 102 c NTU 2

3 Miv - Trng thi, mi tanh

4 pH - 5,9

5 Hmlng cn mg/l 15

6 Hmlng amoni mg/l 1,5

7 Hmlng st mg/l 14

8 Hmlng asen mg/l Khng phthin

9 Hmlng mangan mg/l 3

10 Hmlng Florua mg/l 1

11 Hmlng clorua mg/l 120

12 Tng coliform Vikhun/100ml 300

13 Tng Ecoli Vikhun/100ml 50

Theo s liu cho thy ngun n c ngm c nng Fe v t QCVN:02:2009/BYT v cht lng n c sinh hot V vy phi xy dng quy trnh cng ngh kh st n gi tr t tiu chun (0,5 mg/l).


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B ng 3-2: Thng s nc u ra theo QCVN:02:2009/BYT

STT Ccch tiu n v Gi tr

1 Musc TCU 15

2 Miv - Khng c mi v l

3 c NTU 5

4 Clod mg/l Trong khong 0,3 0,5

5 pH - Trong khong 6,0 8,5

6 Hmlng amoni mg/l 3

7 Hmlng st mg/l 0,5

8 Ch s pecmanganat mg/l 4

9 cng CaCO3 mg/l 350

10 Hmlng clorua mg/l 300

11 Hmlng Florua mg/l 1,5

12 Hm l ng asen tng s mg/l 0,01

13 Coliform tng s Vi khun/100ml 50

3.2. XUT QUY TRNH CNG NGH

3.2.1 Phng n 1


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H nh 3- 1: S quy tr nh cng ngh phng n 1 THUYT MINH PHNG N 1:

N c t ging c tr m bm c p 1 bmcho ln thp lm thong ti y qutrnh lm thong s din ra , qu trnh lm thong ny da vo ngun cung c p oxic ng bc t ng c cnh qut.

Sau khi lm thong n c s ti p tc a qua b lng ngang, b lng ti p ngang c thit k loi tr cc loi cn llng c kh nng lng xung y v mt tr ng

lc, chc nng lu n c li trong b 30 45 pht to iu kin cho qu trnh oxi ha

vi Thng qut gi

Cn

H cha bn

em x l

Cn

Ngun

Tr m bm c p1

Thp lmthong

B lng ti pxc

B lc p lc

Tr m bmc p2

B cha n cs ch

Cht kh trngclo


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v phn hy st xy ra hon ton, ng th i gi mt phn cc cht hu c nng litr c khi qua qu trnh lc

B lc p lc: khi nc i qua b mt lc cc ht cn v vi trng c trong n cs b gi li trn b mt lc.

Sau nc c dn vo b kh trng v i ha cht kh trng l clo loi tr vi sinh vt v vi khun trong n c ngm.

N c sau khi kh trng c dn n b cha n c sch v nh tr m bm c p 2 bm vo mng l i cp n c ca h thng cp n c thnh ph.

3.2.2. Phng n 2: Phng n chn

H nh 3- 2: S quy tr nh cng ngh phng n 2

THUYT MINH PHNG N 2:

Ging Tr m bm c p 1

Lm thong bnggin ma

B cha n csch

Tr m bm c p 2

B lng ngang

B lc p lc

Ha cht (Clohoc vi)

Ha cht kh trngclo

Lng n c r a lc

H

cha bnem x l

N c lng


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N c t ging c tr m bm c p 1 bm lncng trnh lm thong, v i mcch chnh l kh CO2, ha tan oxi t khng kh vo nc oxy ha Fe2+ thnh Fe3+,

Mn2+

thnh Mn4+

(nu c) d dng k t ta, d dng lng ng kh ra khi n cnng cao nng sut ca cc cng trnh lng v lc. Lng oxi ha ta thu c l 55%l ng oxi bo ha v kh c 75 80% CO2 trong n c.

Sau nc c a qua b lc p lc. Ti y, khng ch gi li cc ht cnl lng trong nc c kch th c ln hn kch th c cc l r ng to ra gia cc ht lcm cn gi li keo st, keo hu c gy c, mu.

Sau nc c dn vo b kh trng, v i ha cht kh trng l dung dch

Clo loi tr vi sinh vt v vi khun ctrong n c ngm. N c qua b kh trng c a vo b cha. Sau c tr m bmc p 2 vo

mng l i cp n c thnh ph.

3.3. TNH TON CNG TRNH N V

3.3.1. Tnh ton b lng ngang

a) Tnh ton kch th c b

Vi lu lng n c vo b Q = 1000 m3

/ngy.m =41,67 m3

/h = 0,01157 m3

/s.Din tch b lng tnh theo cng thc:

0UQ

F

Trong :

Q : lu lng n c vo b (m3/h)

U0: ti tr ng b mt hay tc lng ca ht cn (m/h)

: h s k nnh h ng ca dng chy r i trong vng lng

30K

1

1

H s K ph thuc vo t s L/H theo bng sau:


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B ng 3-3: tr s K v ph thu c vo t s L/H

L/H 10 15 20 25

K 7,5 10 12 13,5

1,33 1,5 1,67 1,82

Chn U0 = 0,55 mm/s = 5,510-4 m/s.

Chn t s L/H=15, ta c = 1,5

. F =1,5 = 31,6 m2

T s 5mB

L (theo X l n c c p cho sinh hot v cng nghip ca

TS.Tr nh Xun Lai ).

Chn L = 5B B = = = 2,9 mChiu di ca b lng l:

L = = = 14,4 m

Chn chiu cao vng lng H = 2,5 m (H = 2,5 3,5m)

Vn tc n c chy trong b (V0):

V0 = =

= 1,610-3 m/s = 1,6 mm/s

Thi gian lu (T)

T = = = 6828 (s) = 1,9 (h)(T = 1,53h, theo X l n cc p cho sinh hot v cng nghip ca TS.Tr nh Xun Lai).

b) Thi t k ngn phn ph i

phn phi u trn ton b mt ct ngang ca b cn t cc vch ngn u

mi b, cch t ng 12m. Vn tc n c qua l vch ngn ly bng 0,5 m/s. on


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52

d i ca vch ngn trong phm vi chiu cao 0,30,5m k t mt trn ca vng chacn nn khng cn phi khoan l. (Theo khon 6.77 TCXD 33:2006).

Chn cao lm vic th p nht ca vch ngn so v i mt trn ca vng lng cnl 0,5 m. Khi , din tch cng tc ca vch ngn phn phi n c vo b l:

Fn = B (H 0,5) = 2,9 ( 2,5 0,5) = 5,8 m2

Lu lng nc tnh ton qua b: qn = Q = 1000m3/ngym = 0,01157m3/s

Din tch cn thit ca cc l vch ngn phn phi nc vo l:

= Theo khon 6.77 TCXDVN 33:2006, vn tc nc qua l vch ngn phn phi

ly bng 0,5m/s. Do :

= = 0,0231 m2 Ly ng knh l vch ngn phn phi l d1=0,05m (d1=0,050,15 m theo

trang 73-X l nc cp-TS.Nguyn Ngc Dung)

Din tch 1 l

F1l = = = 1,963510-3 m2Tng s l vch ngn phn phi l:

n1 = = = 11,76 l Chn n1 = 12 l

Cch b tr : B tr 4 hng dc v 3 hng ngang vi s l c l 4x3 = 12 l

c) Thit k ngn thu nc

Thit k ngn thu nc tng t nh ngn phn phi, thit k vch ngn thun c cui b, trn vch ngn c c l hnh trn cho nc i qua. ng knh l trn vch ngn thu n c chn d2= 0,05 m.

Tc n c chy qua l: 0,5 m/s (theo TCXD 33-2006)


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53

Khong cch ti t ng b 0,5m x 1,5m (TCXD 33-2006)

Chn cao lm vic th p nht ca vch ngn thu n c so v i mt trn ca vnglng cn l 1,5 m. Khi , din tch cng tc ca vch ngn phn phi n c vo b l:

Fn = B ( H 1,5) = 2,9 ( 2,5 1,5) = 2,9 m

Din tch cn thit ca cc l vch ngn thu n c cui b

= = = 0,02314 m2 Din tch 1 l:

F2l = = = 1,963510-3 m2Tng s l vch ngn phn phi l:

n2 = = = 11,78 l Chn n2 = 12 l

Cch b tr : B tr 4 hng dc v 3 hng ngang vi s l c l 4x3 = 12 l d) Thi t k vng x c n

Vic x cn d kin tin hnh theo chu k v i th i gian gia hai ln x cn T =24h (T = 6h24h theo TCXD 33:2006)

Th tch phn cha cn ca b: (trang 36/TCXD33-2006)

N)mC(QT

VC

Trong :

T : thi gian gia hai ln x cn. Chn T= 24h

Q : lu lng tnh ton. Q=1000 m3/ngym =41,67 m3/h

N : s lng b lng ngang = 1 b

: nng trung bnh ca cn nn cht (g/m3), ly theo bng 6.8trang 36TCXD 33:2006 . Theo bng 6.8 th = 15000 g/m3


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B ng 3-4: Trch b ng 6.8 trang 36 TCXD 33:2006

Hm l ng cn trong n c ngun Nng trung bnh ca cn nn tnh bng g/m3 sau th i gian

6h 12h 24h

n 50

Trn 50 n 100

Trn 100 n 400

Trn 400 n 1000Trn 1000 n 1500

(Khi x l khng dng phn)

Khi lm mm nc (c cng Magienh hn 25% cng ton phn) bngvoi hoc vi vi sa

Nh trn, nc c cng Magie ln hn75% cng ton phn

9000

12000

20000

3500080000

200000

28000

12000

16000

32000

50000100000

250000

32000

15000

20000

40000

60000120000

300000

35000

C : hm l ng cn trong nc a vo b lng (mg/l), C = 15mg/l

m: Hm l ng cn sau khi lng

V i hiu qu lng 60% tac m c tnh nh sau:

m = 15 (15 0,6) = 6 mg/l

Tnh th tch phn cha cn:

Vc = = 0,6 m3 Chiu cao trung bnh ca vng cha nn cn:

Hc = = = 0,02 m = 20 mm


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Chn ng knh l thu cn vo ng l: Dl= 25 (mm) (Dl 25 mm theoTCXD 33:2006)

Fl = = = 4,910-4 m2 S l cn c trn ng thu cn:

n = = = 16 l V i s l cn c l 16, ta c trnng thu cn hai hng l, mi hng 8 l, b

tr 2 hng l so le nhau 1 gc 450

.e) Tnh kch thc xy dng ca b

Chi u cao xy d ng b

Chiu cao b c tnh n chiu cao bo v l:

HB = H + HBV = 2,5 + 0,5 = 3 m

y b c b tng v i chiu dy 120 mm, suy ra tng chiu cao xy dng

ca b lng (bao gm c chiu cao mng x cn) l:HXD = H + HBV + HM + 0,12 = 2,5 + 0,5 + 0,7 +0,12 = 3,82 m

Chi u di xy d ng b

Xy dng b bng b tng, t ng dy 200 mm, suy ra tng chiu di b lng k c 2 ngn phn phi v thu n c:

LB = L + ( 2 0,2) + (2 1) = 14,4 + 0,4 + 2 = 16,8 m

Tng chiu di ca ton b lng l:

LXD = LB + (2 0,2) = 16,8 + 0,4 = 17,2 m

Chi u r ng xy d ng b

BXD = B + (2 0,2) = 2,9 + 0,4 = 3,3 m

3.3.2. Tnh ton b lc p lc

Tnh ton kch th c b


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B lc p lc c la chn tnh ton thit k s dng hai l p vt liu lc lct thch anh v than antraxit c cc thng s ly theo bng cc ch tiu v vt liu

lc v tc lc ca b lc p lc sau y: (trch t bng 4.10 trang 153- X L N c C p- TS.Nguyn Ngc Dung).

B ng 3-5: Trch b ng 4.10 trang 153 x l n c c p TS Nguy n Ng c Dung

Loi b lc

c im l p vt liu lc Tc lc (m/h)

dmin (mm)

dmax (mm)

dtd (mm) K L (mm) Bnhth ng

V

Tngc ng

Vtc

Lc 1l p

0,5

0,7

1,2

1,5

0,70,75

0,91,0

2,02,2

1,82,0

700800

12001300

10

15

15

20

Lc 2l p 0,5 1,2 0,70,75 2

Ct thchanh

40050015 20

0,8 1,8 1,11,2 2

Thanantraxit

400500

Chn:

Chiu cao l p ct thch anh h1 = 500 mm, ng knh hiu qu dtd = 0,7 mm,h s ng nht K = 2.

Chiu cao l p than antraxit h2 = 500 mm, ng knh hiu qu dtd = 1,1 mm, h s ng nht K = 2.

Tc lc ch bnh th ng V = 15 m/h.

T ng di n tch b m t b l c p l c:

Tng din tch b mt bn lc p lc c tnh theo cng thc:


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F =

Trong :

Q : lu lng nc i vo cc b, Q = 1000 m3/ngy.m = 41,67 m3/h

V : tc lc tnh ton khi b lc lm vic bnh th ng (m/h), chn Vtb = 15m/h

F = = 2,778 m2

Chn s b lc N = 2 b Din tch ca 1 b : f = = = 1,389 m2

ng kch ca 1 b:

d = = = 1,33 mChn d = 1,5 m

Lu lng n c qua mi b :

q = = = 5,7910-3 m3/s

Tnh chi u cao xy d ng c a b

H = H + Hv + Hn + H ph (m)

Trong :

H : chiu cao si (m), chn H = 150 mm ( H = 150200 mm theo TCXD33:2006)

Hv : chiu cao l p vt liu lc

L p ct thch anh cao400500 mm chn = 500 mm

Lp than antraxit cao 400500 mm chn = 500 mm

Hv = 500 + 500 = 1000 mm = 1 m


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qcl.h= Q Lcl = 41,67 1,310-3 = 0,06 kg/h

- L ng clo dng trong 1 ngy

qcl.ngy = 24 qcl.h = 24 0,06 = 1,44 kg/ngy


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CHNG IV: KT LU N V KI N NGH

Vn n c sch cho sinh hot ang l mt trong nhng vn c p thitkhng ch Tp H Ch Minh m cn ca cc thnh ph v vng lnh th trn ton th gi i. Nhu cu s dng n c sch ngy cng nhiu v vy vic x l nc t theo ccquy chun quynh l mt trong nhng gii php m bo cung c p cho nhu cu cangi dn. ng th i phi m bo cho sc khe ng i s dng.

Vi ti: Tnh ton v thit k tr m x l n c ngm b sung cho mngl i cp n c Tp H Ch Minh Q = 1000 m3/ngym. n phn no tm hiu

c ngun gc, tnh cht v thnh phn ca ngun n c cp ( n c ngm). . ncng c gng a ra cc phng n x l, phn tch u im la chn phng phh p v i tnh cht, lu lng n c cp, iu kin kinh t cng nh ch trng n vn din tch mt bng xy dng nh my.

Trong bi n cng khng th trnh khi nhng hn ch v thiu st. Knhmong s gp chn thnh ca thy c. V qua bi n ny em cng knh mong thy,c v nh tr ng s to iu kin hn na, t chc thm nhiu chuyn tham quan thct gip cho chng em c th hc hi thm nhng kin thc b ch.


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