Tnh ton thit k bi chn lp rc thi sinh hot cho khu dn c 300.000 dn

Tnh ton thit k bi chn lp rc thi sinh hot cho khu dn c 300.000 dn

LI NI U

Vic x l cht thi rn sinh hot mt cch hp l v ang l vn cp thit i vi hu ht cc tnh thnh ca nc ta. Lu nay, cht thi rn sinh hot thng c chon lp cc bi rc h, hnh thnh mt cch t pht. Hu ht cc bi chon lp ny t gn st khu dn c, gy ra nh hng v tc ng xu n mi trng v sc khe ca cng ng. mt khc, s gia tng nhanh chng ca tc th ha v mt dn c cng tng thm p lc cho h thng qun l cht thi rn hin nay. Vic la chn cng ngh x l cht thi rn sinh hot c ngha ht sc quan trong i vi cng tc qun l, bo v mi trng.Trong rt nhiu cc cng ngh x l cht thi rn, th chon lp hp v sinh l phng php kh thi, ph hp nht i vi iu kin kinh t- x hi ca nc ta hin nay. Cht thi rn sinh hot c x l tp trung, c c s khoa hc, k thut, m bo khng gy nhim mi trng, nhm tin ti ng ca cc khu x l rc t pht, tm thi.Trong bi tiu lun ny, nhm em xin trnh by ti: Tnh ton, thit k mt bi chon lp rc thi sinh hot hp v sinh cho mt khu dn c 300 000 dn.Trong qu trnh tnh ton, thc hin, nhm chng em khng trnh khi c nhng sai st, knh mong thy v cc bn gp chng em c th hon thin bi tiu lun ny.Xin chn thnh cm n!

Nhm sinh vin thc hin.

MC LCTrangLi ni u...1

Chng 1. KHI QUT V CHT THI SINH HOT..41.1. KHI NIM41.2. THNH PHN CHT THI RN SINH HOT.41.3. TCH CHT L HA CA CHT THI RN SINH41.4. HIN TRNG CA CHT THI RN SINH HOT.5

Chng 2. CC PHNG PHP X L CHT THI SINH HOT72.1. PHNG PHP TRUYN THNG.72.2.1. Tp trung thnh bi rc. ..72.1.2. Phng php t.....72.1.3. Phng php chn lp..82.2. PHNG PHP X L BNG CNG NGH HIN I..112.2.1. Phn loi rc, ti ch rc hu c thnh phn vi sinh..112.2.2. S dng cng ngh x l nhit phn rc122.2.3.Phng php 3R. 132.2.4.X l cht thi rn bng cng ngh p kin14

Chng 3. TNH TON XY DNG BI CHN LP CHO KHU VC C 300.000 DN ...153.1. TNH TON LN RC THI CN X L ..153.2. TNH TON CHN LP.163.3. CHNG THM CHO CC CHN LP18Kt lun22Ti liu tham kho.23

Chng 1KHI QUT V CHT THI SINH HOT

1.1. KHI NIM Cht thi l ton b cc vt cht b con ngi loi b trong cac hot ng kinh t- x hoi, bao gm cc hot ng sn xut v duy tr s tn ti ca cng ng. Cht thi rn l cht thi th rn, c thi t qu trnh sn xut, kinh doanh, dch v, sinh hot hoc cc hot ng khc. Cht thi rn bao gm cht thi rn thng thng v cht thi rn nguy hi.Cht thi rn sinh hot l cht thi rn sinh ra t cc khu nh ( bit th, h gia nh,chung c), khu thng mi ( ca hng,siu th,ch), c quan( trng hc, bnh vin, cc trung tm hnh chnh nh nc), khu cng cng ( qut ng, cng vin, gii tr, ta cy xanh), cc trm x l nc thi. Cht thi rn sinh hot bao gm c cht thi nguy hi sinh ra t cc ngun trn.

1.2. THNH PHN CHT THI RN SINH HOT Bng 1.1. Cc loi cht thi c trng t ngun thi sinh hotKhu dn c, thng mi, cng sCht thi thc phm, nha,giy, carton, vi, cao su, rc vn, nhm, kim loi cha st, cc loi khc: t lt, khn v sinh,.

Cht thi t dch vRa ng : Bi rc, xc ng vt, xe hng, c, l, cc ng kim loi, nha tng hp, can, v chai

Cht thi c bitCht thi th tch ln, in gia dng, hng ha, pin, du xe, lp xe, linh kin in t, cht thi nguy hi.

1.3. TCH CHT L HA CA CHT THI RN SINH Khi lng ring ca cc loai cht thi rn rt khc nhau tu tng trng hp: rc t nhin, rc trong thng khng nn, c nn Khc nhau ty theo v tr a l, ma, thi gian lu tr Khi lng ring ca cht thi rn ly t cc xe p rc sinh hot thng dao gn trong khong t 178kg/m3 n 415kg/m3. m ca cht thi rn thng tnh theo 2 cch: theo thnh phn % khi lng t v % khi lng kh. Kh nng tch m l tng lng m m cht thi c th tch tr c, kh nng tch m s thay i ty theo iu kin nn p rc v trng thi phn hy ca cht thi. Kh nng tch m ca CTRSH trong trng hp khng nn c th dao ng trong khong 50%-60%. Cc nguyn t c bn trong CTRSH bao gm Carbon, Hydro, Nito, Lu hunh v tro. Cc nguyn t thuc nhm Halogen c xc nh do cc dn xut ca clo tn ti trong kh thi khi t rc.

1.4. HIN TRNG CA CHT THI RN SINH HOT Lng cht thi rn sinh hot ti cc th nc ta pht sinh ngy cng tng, tnh trung bnh mi nm tng khong 10-15% .T l tng cao tp trung cc th ang m rng, pht trin mnh c v quy m ln dn s v cc khu cng nghip, nh cc th tnh Ph Th (19,9%), thnh ph Ph L (17,3%), Hng Yn (12,3%), Rch Gi (12,7%), Cao Lnh (12,5%)... Cc th khu vc Ty Nguyn c t l pht sinh cht thi rn sinh hot tng ng u hng nm v vi t l tng t hn (5,0%). Theo thng k nm 2002, lng CTR sinh hot trung bnh t 0,6-0,9 kg/ngi/ngy cc th ln v 0,4-0,5 kg/ngi/ngy cc th nh, th trn th t. n nm 2008 v u 2009, t l ny cc th ln tng ln tng ng l 0,9-1,3 kg/ngi/ngy( bng 2). Kt qu iu tra tng th nm 2006 - 2007 cho thy, th c lng cht thi rn sinh hot pht sinh ln nht l TP. H Ch Minh (5.500 tn/ngy), H Ni (2.500 tn/ngy); th c lng cht thi rn pht sinh t nht l Bc Kn - 12,3 tn/ngy; Th x Gia Ngha 12,6 tn/ngy, Cao Bng 20 tn/ngy; TP. ng Hi 32,0 tn/ngy; TP Yn Bi 33,4 tn/ngy v th x H Giang 37,1 tn/ngy.Nh vy,lng cht thi rn sinh hot th pht sinh ch yu tp trung 2 th c bit l H Ni v TP. H Ch Minh. Tuy ch c 2 th nhng tng lng cht thi rn sinh hot pht sinh ti 8.000 tn/ngy (2.920.000 tn/nm) chim 45,24% tng lng cht thi rn sinh hot pht sinh t tt c cc th. Tnh theo vng a l (hay vng pht trin kinh t - x hi) th cc th vng ng Nam B c lng cht thi rn sinh hot pht sinh ln nht ti 6.713 tn/ngy hay 2.450.245 tn/nm (chim 37,94% tng lng pht sinh cht thi rn sinh hot cc th loi III tr ln ca c nc), tip n l cc th vng ng bng sng Hng c lng pht sinh cht thi rn sinh hot th l 4.441 tn/ngy hay 1.622.060 tn/nm (chim 25,12%). Cc th khu vc min ni Ty Bc B c lng pht sinh cht thi rn sinh hot th thp nht ch c 69.350 tn/nm (chim 1,07% ), tip n l cc th thuc cc tnh vng Ty Nguyn, tng lng pht sinh cht thi rn sinh hot th l 237.350 tn/nm (chim 3,68%).Ti cc thnh ph, vic thu gom v x l cht thi th thng do Cng ty Mi trng th (URENCO) m nhn. Tuy nhin xut hin cc t chc t nhn tham gia cng vic ny ( Cng ty Huy Hong, Tp.Lng Sn...).Hu ht rc thi khng c phn loi ti ngun,thng thu gom ln ln v vn chuyn n bi chn lp. T l thu gom tng t 40% - 67% nm 2002 ln n 70 - 75% nm 2007 cc thnh ph ln, cn cc th nh t l ny tng ln ti 30% - 50% T l thu gom bnh qun ton quc vo khong 55%.-C ch qun l ti chnh trong hot ng thu gom rc thi ch yu da vo kinh ph bao cp t ngn sch nh nc, cha huy ng c cc thnh phn kinh t tham gia, tnh cht x hi ho hot ng thu gom cn thp, ngi dn cha thc s ch ng tham gia vo hot ng thu gom cng nh cha thy r c ngha v ng gp kinh ph cho dch v thu gom rc thi.

Chng 2CC PHNG PHP X L CHT THI SINH HOT

Do rc thi sinh hot c cha nhiu thnh phn trong c nhng thnh phn c th ti ch v thnh phn khng th ti ch. Trong nhiu nm qua cc nh nghin cu; cc nh hoch nh, a ra nhiu phng n x l rc thi sinh hot cho vic x l c hiu qu cng nh tn thu ti nguyn. Sau y l mt s phng php

2.1. PHNG PHP TRUYN THNGCc phng php ny tp trung ch yu vo cc phng php n gin v c tnh ph bin cao Vit Nam2.2.1. Tp trung thnh bi rc.Ngoi cc bi rc ln xa khu dn c, c qu nhiu bi rc , ang tn ti xung quanh nh dn, trn khu vc ch, trong cng vin, trn sng ngi, cc knh mngu im: Khng mt cng thu dn v nhanh chng cho ngi x rc. Mang tnh t pht cao (ch yu l do thc ngi dn chc ch c Vit Nam)Nhc im: Thi gian to thnh bi rc ln l nhanh Qu trnh phn hy l t nhin nn khng th kim sot mi v cc cht c hi Cc cht thi c tnh nguy hi khng c x l v c th lan ra cc khu vc ln cn gy nh hng ti sc khe con ngi2.1.2. Phng php t.t rc l giai on x l cui cng cho mt s loi rc khng th x l bng cc phng php khc. y l mt giai on oxy ha nhit cao vi s c mt ca oxy trong khng kh, trong cc rc c hi c chuyn ha thnh kh v cc cht thi rn khc khng chy. Vic x l rc bng phng php t c ngha quan trng l lm gim ti mc nh nht cht thi cho khu x l cui cng, nu s dng cng ngh tin tin cn c ngha cao bo v mi trng. y l phng php x l rc tn km nht so vi phng php chn lp hp v sinh th chi ph t mt tn rc cao hn khong 10 ln. Cng ngh t rc thng p dng cc quc gia pht trin v phi c mt nn kinh t mnh bao cp cho vic thu t rc sinh hot nh l mt dch v phc li x hi ca ton dn. Tuy nhin t rc sinh hot bao gm nhiu cht khc nhau sinh khi c v d sinh ioxin nu vic x l khi khng tt (phn x l khi l phn t nht trong cng ngh t rc).u im Phng php ny l gim c th tch v khi lng, ca cht thi n 70 - 90% so vi th tch cht thi ban u. (Gim mt cch nhanh chng, thi gian lu tr ngn) C th t ti ch khng cn phi vn chuyn i xa Nhit ta ra ca qu trnh t c th s dng cho cc qu trnh khc. Kim sot c nhim khng kh, gim tc ng n mi trng khng kh C th s dng phng php ny x l phn ln cc cht thi hu c nguy hi. Yu cu din tch nh hn so vi phng php x l bng sinh hc v chn lp. nhim nc ngm t hn i vi phng php x l bng chn lp. X l trit cc ch tiu nhim ca cht thi rn. Gim th tch ti a sau khi x l, cho nn tit kim c din tch chn. Tro thi ra sau khi t thng l nhng cht trNhc im Vn hnh dy chuyn phc tp, i hi k thut v tay ngh cao. Chi ph u t ban u ln. Khng phi mi cht thi u c th t c Phi b sung nhin liu cho qu trnh t2.1.3. Phng php Chn lpNu chn lp m khng c kim sot, cht thi rn cng s gy ra nhiu nguy c khc i vi sc kho cng ng v i vi mi trng. V cng ngh tng i n gin kh linh hot, chn lp hp v sinh c ngha l chn lp cht thi rn kh kim sot, c xem l phng php qun l vic thi b cht thi rt ph hp i vi cc nc ang pht trin. Chn lp hp v sinh gip hn ch s tip xc ca con ngi v mi trng vi cc nh hng c hi ca cht thi rn b b trn mt t.Thng qua chn lp hp v sinh, cht thi c tp trung vo 1 khu vc c thit k cn thn sao cho s tip xc gia cht thi v mi trng gim ng k.2.1.3.a. Phn loi bi rc chn lpBi chn lp cht thi rn c th c phn loi theo nhiu hnh thc khc.Theo loi cht thi c chn lp. Bi chn lp rc sinh hot Bi chn lp cht thi cng nghip Bi chn lp cht thi nguy hi Bi chn lp tro x.Theo kch c quy m din tch bi chn lp c phn thnh: Bi chn lp nhC din tch nh hn10 ha Bi chn lp trung bnhT 10 - 30 ha Bi chn lp lnT 30 n 50 ha Bi chn lp rt lnTrn 50 haTheo kt cu bi chn lp c chia thnh ba loi: Bi chn lp ni: Cht thi c cht cao ln mt t, bi chn lp ny thng c p dng ti cc vng t phng, xung quanh bi chn lp phi c h thng k cch ly cht thi, nc rc vi mi trng xung quanh. Bi chn lp chm: Cht thi c chn lp su di mt t v c cch ly vi mi trng ngoi thng qua h thng lt y v lp ph bn trn. Bi chn lp na chm na ni: Mt phn c chn lp su di t, mt phn ni ln trn mt t.2.1.3.b. Yu cu ca bi chn lpKhi xy dng bi chn lp cht thi rn chng ta cn xt cc yu cu sau:V trGn ni sinh ra ngun rc.V tr bi chn lp tng i cao, trnh nhng vng b l lt.Bng 2.1. V tr ca bi rc n mt s cng trnhCccng trnhc im v quym cng trnhKhong cch ti thiu t vnh ai cng trnh ti cc bi chn lp, (m)

Bi chn lp nh v vaBi chn lp lnBi chn lp rt ln

thCc thnh ph, th x, th trn, th t...3000 - 50005000 - 1500015000 - 30000

Sn bay, cc khu cng nghip, hi cngt quy m nh n ln1000 - 20002000 - 30003000 - 5000

Cm dn c ng bng v trung du> 15 hcui hng gi chnh> 1000> 1000>1000

cc hng khc> 300> 300> 300

Cm dn c min nitheo khe ni (c dng chy xung)3000-5000> 5000> 5000

Cng trnh khai thc nc ngmc.sut < 100 m3/ngQ < 10.000 m3/ngQ > 10.000 m3/ng50 - 100> 100> 500> 100> 500> 1000> 500> 1000> 5000

a cht cng trnh thu vn. Bi chn lp trnh nhng vng c nn t yu, cc vng hay xy ra chn ng a cht, cc vt nt,... Trnh nhng vng c cu to nn vi. Cch xa khu vc c tr nc ngm ln. Nhng khu vc c hm lng st trong t cao rt thun li xy dng cc bi rcCc hng mc trong bi chn lp i vi bi chn lp m bo yu cu v sinh, cc hot ng chn lp thc hin mt cch lin tc yu cu bi chn phi c cc hng mc cng trnh sau: chn lp (i vi bi chn lp c nhiu ) H thng thu gom v x l nc rc H thng thu gom v x l kh bi rc Ly mu v phn tch mu nc rc, kh rc H thng ng giao thng Trm cn quan l lng rc thi chn lp. Khu nh hnh chnh v cc c so bo dng cc phng tin my mc hot ng trong bi chn lp. H thng tng ro bao quanh. H thng thot nc ma. u im. C th tn thu cc kh sinh ra trong qu trnh phn hy Chi ph u t cng nh duy tr thp. Qu trnh vn hnh d dngNhc im. Cn din tch ln v thi gian x l di. Cn c cc bin php tt kim sot nc r rc cng nh kh metan sinh ra trong qu trnh phn hy.

2.2. PHNG PHP X L BNG CNG NGH HIN ICc phng php hin i sau y s l mt trong nhng gii php x l cht thi sinh hot mang tnh cng ngh. Cc phng php hin i ny s em li nhiu tin ch v kinh t cng nh mi trng.2.2.1. Phn loi rc, ti ch rc hu c thnh phn vi sinhPhng php ny thng i km vi cc bin php khc nhm gim thiu lng cht thi hu c em dt hoc chn lp. Nguyn liu thng l rc hu c t rc thai sinh hot ( c phn loi) hay t cc nh my ch bin thc phm hoc nng sn. Khng ging vi cc loi rc thi sinh hot khc, lng cht thi thc phm c th c gim xung mt phn ba bng cch sy kh. Nh my loi b cht c hi v kim loi nng t cht thi thc phm, ri sy kh, nghin nh, v iu chnh mn lm thc n gia sc giu dinh dng. Cht thi thc phm trc y c a thng n bi cha rc, nhng nay tr thnh ngun nhin liu thay th qu gi v thc n gia sc.Tn dng ch bin rc thi hu c ngay ti ngun s gim thiu rc thi phi chuyn ch n bi chn lp, tit kim kinh ph cho Nh nc v nhn dn, tit kim ti nguyn t, ko di tui th cc bi chn lp, tn dng c cht thi, em li li ch kinh t, gn vi bo v mi trng.u im Gim lng cht thi pht sinh (khong 50% lng cht thi sinh hot). To ra sn phm phn hu c phc v cho trng trt (thay th mt phn cho phn ha hc, to xp cho t, s dng an ton, d dng). Gp phn ci to t (gip tng mn, ti xp ca t) Tit kim bi chn lp, gim nh hng gy nhim mi trng ca cht thi rn. Vn hnh n gin, d bo tr v kim sot cht lng sn phm. Gi thnh x l tng i thp.Nhc im Yu cu din tch t xy dng nh xng ln. Cht lng sn phm cha cao, cha n nh. Gp kh khn khi tiu th sn phm. Mc t ng ca cng ngh khng cao. Vic phn loi cn mang tnh th cng nn thng nh hng n sc kho ca cng nhn lm vic Np nguyn liu th cng do vy cng sut km.

2.2.2. S dng cng ngh x l nhit phn rc L phng php tin tin trn th gii trong bo v mi trng. Nhng phng php ny ch p dng c cho cc khu cng nghip, ng dn c.

Nguyn l:Rc thiDu nng, nhThan tng hpKh hidroNcNhit phn (500oC)Nguyn liu ti sinh

2.2.3.Phng php 3R.3R l Reduce/Gim thiu - Reuse/Ti s dng - Recycle/Ti ch.Qu trnh ti ch gip ngn cho rc khng phi chn xung t hay t chy, gim bt lng tiu th nguyn liu th, v gim c lng nng lng phi s dng hn so vi qu trnh sn xut t nguyn liu th. Cc nguyn liu ph bin c ti ch l thu tinh, giy, nhm, hc n, thp, vi v nha. Cc nguyn liu ny c th l rc thi t qu trnh sn xut hoc l rc thi tiu dng. Ti ch l yu t ch cht ca vic qun l rc thi hin i. Cng ngh ti ch cht thi ti cc lng ngh hu ht l c v lc hu, c s h tng yu km, quy m sn xut nh dn n tnh trng nhim mi trng nghim trng mt s ni. Mt s lng ngh ti ch hin nay ang gp nhiu vn mi trng bc xc nh Ch o (Hng Yn), Minh Khai (Hng Yn), lng ngh sn xut giy Dng (Bc Ninh) Mt s cng ngh c nghin cu p dng nh trong ch yu ti ch cht thi hu c thnh phn vi sinh (SERAPHIN, ASC, Tm Sinh Ngha) hay vin nhin liu (Thy lc my-H Nam) song kt qu p dng trn thc t cha tht kh quan. Nhn chung, hot ng ti ch Vit Nam khng c qun l mt cch c h thng, c nh hng m ch yu do cc c s t nhn thc hin mt cch t pht.Phng php thc hin l rc s c phn loi ti ngun, rc v c v rc hu c c tch ring v phn u n nm 2010 s tn dng c 30% rc. Nhng loi rc hu c v ang c s dng lm phn bn. Cc loi rc nh ni-lng, ba giy loi, nha... s c ti ch dng lm nguyn liu. Cn cc loi rc v c khc c ti ch thnh vt liu xy dng nh cp thp c dng cho cc cng trnh cnh quan th. Nh vy, phn rc cn chn lp s gim i u im. Phn loi ti ngun thi s gim chi ph cng nh cc khu phn loi cho ni tip nhn (nh my hay bi chn lp) Tng hiu sut ti ch v chuyn i cht thi thnh dng khc Tng kh nng x l rc thi sinh hot cng nh gim nhim mi trng C th t khu phn loi tm ra nhng vt dng c th ti s dng khng cn thng qua ti chNhc im. Cn nhiu thng ch cng xe ch rc cc loi (trnh ln rc phn loi) thc hin tt th vic tuyn truyn cng mt nhiu cng sc.2.2.4.X l cht thi rn bng cng ngh p kinp kin c thc hin trn c s ton b cht thi c tp trung thu gom vo nh my, rc c phn loi th cng , cc cht c th ti ch c phn loi ring, cc cht cn li c chuyn qua h thng nn p bng thu lc vi mc ch lm gim th tch ti a to thnh kin. Cc kin ny c s dng cho nhiu mc ch khc nhau nh p , san bng cc vng t trng sau khi ph ln cc lp t ct.n nh cht thi rn bng cng ngh Hydromex. y l cng ngh mi. Cng ngh Hydromex nm x l rc thi th thnh cc sn phm phc v xy dng, lm vt liu, nng lng v sn phm nng nghip hu ch. Bn cht ca cng ngh Hydromex l nghin nh rc sau polyme ho v s dng p lc ln nn p nh hnh cc sn phm.

Chng 3TNH TON XY DNGBI CHN LP CHO KHU VC C 300.000 DN

3.1. TNH TON LN RC THI CN X L Gi thit cc yu t ban u. Bi chn lp cho khu th c 300.000 dn, hot ng trong 15 nm. Tc gia tng dn s qua cc nm l 2%. Lng rc pht sinh 0,6 kg/ngi/ngy. T l thu gom rc l 80% lng rc pht sinh. T l rc c ti ch l 15%, buc phi thiu t l 0.5%, lm phn vi sinh 5% trn tng lng rc c thu gom. Trng lng ring ca rc thi sau khi nn cht l 0,8 tn/m3.T nhng gi thit ban u trn ta lp c bng cc thng s sau.Bng 3.1. Tnh ton lng rc thi sinh raNm hot ngS dnLng rc pht thiLng rc thu gom cLng rc tch lyKhi lng rc em chn lpTh tch rc chn lp

NgiTn/nmTn/nmTnTnm3

130000065700525605256041785.252231.5

23060006701453611.2106171.284406.1105507.6

331212068354.354683.4160854.6127879.4159849.3

431836269721.455777.1216631.7172222.2215277.8

532473071115.856892.6273524.4217451.9271814.8

633122472538.158030.5331554.8263586.1329482.6

733784973988.959191.1390745.9310643.0388303.8

834460675468.660374.9451120.9358641.1448301.3

935149876978.061582.4512703.3407599.1509498.9

1035852878517.662814.1575517.3457536.3571920.4

1136569880087.964070.3639587.7508472.2635590.3

1237301281689.765351.8704939.4560426.9700533.6

1338047183323.566658.8771598.2613420.6766775.7

1438808284990.067992.0839590.2667474.2834342.8

1539584486689.869351.8908942.0722608.9903261.1

Nh vy ta tnh c tng th tch rc cn chn lp sau 15 nm l 903261 m3.3.2. TNH TON CHN LPCc yu cu v cu toV c bn cc h chn lp c kt cu dng hnh chp ct ch nht na ni na chm c c trng bi cc yu t su, chiu cao, chiu rng mt h, chiu di mt h, chiu rng y h, chiu di y h v dc vch.Yu cu v chiu cao v suChiu su l khong cc t mt t n y h chn lp cn chiu cao l khong cch t mt h rc n mt t hin ti, tng chiu cao v chiu su c gi l chiu su ton th.Chiu cao v chiu su c xc nh da trn cc yu t ph thuc sau: Chiu su ton th cng ln th din tch mt bng cng nh. Vic thit k phi m bo sao cho chiu su ton th ca bi phi t 15-25m. Chiu su ca h chn lp khng c qu su, ti thiu phi cao hn mc nc ngm 1m. Chiu cao ca h chn s nh hng n cc yu t vn chuyn, thot nc,Yu cu v chiu rngChiu rng ca h chn lp phi m bo cho cc phng tin thi cng v vn chuyn c th hot ng d dng.Yu cu v dc vch dc ca vch ph thuc vo nhiu yu t c bit l c im a cht v iu kin thi tit ca khu vc. dc ln lm gim din tch mt vch, thot nc nhanh nhng c nguy c sp cao. Thng thng dc c chn l 2/3.Yu cu v thi gian s dngTheo quy nh th mi chn lp khng c hot ng qu 3 nm.Yu cu khc gim lng nc ma trn vo cc h th cc h chn lp s c ngn cch vi nhau bi mt b cao 1 m, chn rng 2m, mt rng 0,5m.Cc lp rc dy ti a 1m sau khi m nn k, gia cc lp c cc lp t xen k dy 0,1m.Tng lng cht bao ph chim 28-30% th tch h.Tnh ton sc cha ca mt Da vo cc yu cu trn ta chn mt s thng s ban u cho chn lp nh sau: Chiu rng mt h (a) =50m Chiu di mt h (b) =150m Chiu cao ton phn (h) =15m, trong chiu su (hc) =4m, chiu cao (hn) = 11m, dc = 2/3. Chiu cao lp ph b mt (hp) = 1,5m cc lp rc (dr) dy 1m, lp t xen k (d) dy 0,1m.Nh vy, s lp rc chn lp cho 1 (L)

Chiu cao hu dng (hhd)

Chiu dy lp vt liu ph

Th tch 1 chn lp c tnh nh sau:

Vi: Do dc ca thnh l 2/3 nn ta c :

T : Vn= 43610,77 m3 v Vc=25353,82 m3Vy th tch ca mi chn lp l: V= 68964,59 m3.Tuy nhin, th tch bn trn bao gm c th tch ca cc lp vt liu ph do th tch rc c chn lp trong mi s nh hn th tch ca .Gi s, th tch ca cc lp vt liu ph chim 28% th tch ca chn lp, khi th tch rc trong mi s l: Vrc = V*72/100 = 68964,59*72/100 = 46954,5 m3. Vi th tch rc chn lp cho mi nh th ny th thi gian hot ng ca mi l di mt nm. Do m bo c quy nh l mi hot ng trong thi gian di 3 nm.T kt qu tnh ton lng rc pht thi trn ta c th tnh c s lng chn lp:

Khong cch gia cc chn bng 5m, t ta tnh c tng din tch mt bng cho bi chn lp: F = 18*150*50 + 5*17*150 = 147750 m2 = 14,8 ha.

3.3. CHNG THM CHO CC CHN LPTrong qu trnh x l, vn hnh bi chn lp vn nc r rc l vn rt ng lo ngi khi chng thm c xung t v vo ngun nc ngm. Nguyn tc, yu cuKt cu chng thm phi m bo t hiu qu thu c nc r rc trong ti thiu l 15 nm.Vt liu chng thm phi khng b n mn, c bn trn 15 nm.Vt liu chng thm phi c bn c hc tt chng chu c cc lc nn p, un ln.Kt cu phi thun li cho vic gia cng v s dng, gi c ph hp v c sn.Kt cu chng thm y H thng lp lt y bi chn lp c nhim v gi v ngn cn s xm nhp ca nc r rc vo long t v ngun nc ngm.Bng 3.2. Cc thnh phn ca lp chng thm ySTTLpVt liu dyChc nng

1t hin hu m chtt hin huChng lc, chu ln

2t st nnt st0,6mH tr chng thm v chng ln

3Vi a chtHDPE2 mmChng thm, thu gom nc r v mng dn

4Ct + SiCt, si0,3mLc cc cht rn, to iu kin cho vic thu gom nc r

5Vi lc a cht1,5 mmLc cc cht cn trong nc r, trnh tc nghn

6t m chtt0,6mBo v lp thot nc v l lp phn cch

Hnh 3.1. Cu to lp chng thm y chn lp

Kt cu chng thm mt vch V c bn chng thm cho mt vch cng nh cc lp lt y. Tuy nhin phi chu lc thp hn nn cc lp chng thm mt vch chng lp mng hn so vi y.Lp chng thm polymer l lp chng thm c bn ca chn lp. Vt liu l cc loi mng c sn xut vi din tch khng l, c kh nng chu n mn, nn p, ln cc b, n hi cc tt.Bng 3.3. Cc thnh phn ca lp vchSTTLpVt liu dyChc nng

1t hin hu m chtt hin huChu lc, chng ln

2t dt nnt st0,3mH tr chng thm v chng ln

3Plyme chng thmHDPE2mmKhng cho nc thm qua

Kt cu chng thm bao ph b mtC nhim v ngn khng cho nc ma xm nhp vo bi rc, ng thi ngn khn cho cc loi sinh vt o hang c ng trong long bi rc.Bng 3.4. Cc thnh phn ca lp ph b mtSTTLpVt liu dyChc nng

1t pha stt pha vi 30% st0,6mm bo kh nng m nn, tng kh nng chng thm, lm nn cho cc lp sau

2Vi a chtHDPE2mmNgn khng cho nc ma xm nhp vo chn lp

3Ct thot ncCt0,3mH tr kh nng thot nc ma.

4tt0,6mLp bo v ngoi cng

5Thc vt to cnh quanThc vtTo li cnh quan nh cc khu vc xung quanh.

Hnh 3.2. M phng cc lp bao ph b mtLp vt liu che ph hng ngyRc sau khi c m nn n day 1m s c ph mt lp t dy 0,1m v rc thm vi bt trnh s phn tn cc loi vi sinh vt vo mi trng. Mi ngy khi cng vic chn lp kt thc m cha cao 1m th s dng mng HDPE ph tm ln trn, v lp mng ny s c cun ln vo ngy lm vic tip theo.

Hnh 3.2. Mt ct ngang ca chn lp sau khi ng ca

KT LUNTrong xu th pht trin kinh t, x hi vi tc th ha ngy cng tng, ko theo lng cht thi pht sinh t nhng hot ng sinh hot ca ngi dn ngy cng nhiu v a dng hn v thnh phn, tnh cht. hin c rt nhiu gii php x l: t, lm phn vi sinh, hidro tch,.. tuy nhin khng ph hp vi iu kin ca nc ta do gi thnh cao, k thut phc tp. Do , thit k bi chon lp hp v sinh l phng php x l cht thi rn sinh hot hp l, kinh t nht. y l phng php x l cht thi rn ph bin cc quc gia ang pht trin, v nhiu nc pht trin vn p dng phng php ny. p dng tt phng php chn lp hp v sinh s c nhng hiu qu ng k trong vic bo v mi trng, cng nh gii quyt c tnh trng tn ng v x l theo phng php tm thi hin c hu ht cc th, tnh thnh. pht trin bn vng- bo v mi trng, nh nc v cc c quan chc nng cn c cc chnh sch quan tm v u t nhiu hn na ti vn qun l v x l cht thi rn, m cc lp tp hun rng ri, tuyn truyn v cng tc bo v mi trng, cc phng thc thu gom v phn loi ti ngun, gip cho vic x l v sau c thun li.Khi xy dng bi chn lp hp v sinh cn m bo cc k thut chn lp, ng thi c y cc thit b ph tr nhm hn ch nhim do nc r r, thng thong kh, phng chng chy n. ng thi thng xuyn nh k gim st, kim tra bi chn lp kp thi khc phc nhng s c nhim.

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