Quản lý tổng hợp chất thải ở Campuchia, Lào và Việt Nam: Lý luận và thực tiễn Tác giả: GS. TS. Trần Hiếu Nhuệ&GS. TS. Virginia Maclaren (bt) Dự

8/14/2019 Qun l tng hp cht thi Campuchia, Lo v Vit Nam: L lun v thc tin Tc gi: GS. TS. Trn Hiu Nhu&

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Li gii thiu

D n Kinh t cht thi c tn y l "Kinh t cht thi: Cht thi phc

v nn kinh t" (ting Anh gi tt l WASTE-ECON). y l D n 5 nm

(2000-2005) do T chc Hp tc Pht trin Quc t ca Canaa (CIDA) ti tr

cho 3 nc Vit Nam, Lo v Campuchia vi s h tr k thut ca cc chuyn

gia Canaa. Mc ch tng th ca D n l xy dng ngun nhn lc v nng

lc th ch Vit Nam, Lo v Campuchia thc hin cc cch tip cn qun

l tng hp cht thi nhm mc ch lm cho cht thi phc v nn kinh t, mi

trng v ci thin cht lng cuc sng cho cc cng ng lin quan trc tipn cht thi, gim bt cc nh hng tiu cc ca cht thi i vi h.

Qun l tng hp cht thi l cch tip cn mi i vi 3 nc ni trn.

Trong khun kh ca D n WASTE-ECON, cc chuyn gia ca i hc

Toronto v i hc Waterloo, Canada cung cp, chuyn giao cc tri thc v

kinh nghim v qun l tng hp cht thi cho cc nh nghin cu, ging dy v

qun l cng nhgip thc hin th nghim ng dng cc tri thc ny ba

nc. n phm ny tp hp kt qu nghin cu v th nghim ca cc chuyn

gia bn nc Canada, Campuchia, Lo v Vit Nam tham gia D n, phn nh

khng ch thc t cc hot ng qun l cht thi, kinh nghim trong qun l

cc hot ng ny mi nc m cn c cc vn , cc thiu ht trong qun l

cht thi, cc d bo din bin cng nhcc gi v chnh sch qun l cht

thi trn quan im qun l tng hp cht thi.

c gi c th thy trong cc phn vit nhng c th, sc thi ring ca

qun l cht thi mi nc, ng thi cng thy c nhng vn chung trong

qun l cht thi tt c cc nc. l s gia tng v khi lng, v tnh cp

bch trong qun l cht thi m vic gii quyt chng mt cch hiu qu v bn

vng cn da trn quan im qun l tng hp cht thi.

Nh tn gi ca cun sch, kt cu ca cun sch bao gm hai phn:

phn l thuyt v phn thc tin. Mt kt cu nhvy, theo chng ti, gip chongi c d dng trong nh hng la chn vn quan tm. Cun sch c

xut bn Vit Nam bng bn ting Vit v bn ting Anh. Nhng ngi bin

tp chnh cho cun sch l GS. TS. Trn Hiu Nhu v GS. TS. Virginia

Maclaren.

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Xut bn cun sch ny chng ti hy vng cung cp mt ti liu tham

kho hu ch ca D n Kinh t cht thi cho cc nh nghin cu, ging dy,

qun l, hoch nh chnh sch c quan tm v qun l tng hp cht thi Vit Nam.

Chng ti xin chn thnh cm n cc tc gi Vit Nam v quc t vi tri

thc v kinhnghim phong ph ca mnh to ra ni dung rt hp dn ca

cun sch. ng thi, Chng ti cng chn thnh cm n T chc CIDA ti

tr cho vic xut bn cun sch ny.

Cui cng, Chng ti chn thnh cm n nhng c gng to ln ca nhng

ngi trc tip hon thin v gip cho cun sch ra i vi cht lng v

hnh thc tt nht. l nhng ngi bin tp chnh (GS. TS. Trn Hiu Nhu

v GS. TS. Virginia Maclaren), nhng ngi c k thut bn in n ting Vit(ThS. Tng Th Cng v b Nguyn Th Ngc Khu).

Xin trn trng gii thiu.

GS. TS. Virginia Maclaren,

Gim c D n Kinh t Cht thi pha Canada.

TS. Nguyn Danh Sn,

Gim c D n Kinh t Cht thi pha Vit Nam.

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Phn thuyt

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Gii thiu v qun l tng hp cht thi

Virginia MaclarenVic qun l cht thi cc nc ng Nam thng c hai vn ch

yu : mt l lm th no thu gom ht cht thi rn pht sinh v hai l chn lpchng mt cch ph hp vi mi trng. Tiu im ca cun sch ny l qun

l tng hp cht thi(QLTHCT), i khi cn c gi l qun l tng hp chtthi bn vng(Van de Klundert and Anschutz 2001). QLTHCT l cch tip cnmi trong qun l cht thi, n a ra nhng cch thc qun l khc nhau gipgim bt ng thi sc p v thu gom v chn lp cht thi. Cch tip cn nylm tng tnh bn vng c v mi trng, c v kinh t v x hi ca h thngqun l cht thi ni chung.

Thut ng tng hp c ngha l ni kt hay phi hp vi nhau. Qun ltng hp cht thi bao gm t nht ba loi phi kt hp sau: (1) Phi kt hp ccchin lc qun l cht thi, (2) Phi kt hp cc kha cnh x hi, kinh t, lutphp, chnh tr, th ch, mi trng v cng ngh trong qun l cht thi, v (3)

Phi kt hp kin,

u tin v nng lc cung cp dch v ca cc nhm linquan. Hnh 1.1 minh ho tng loi phi kt hp ny v chng cng s c mt chi tit hn cc mc tip theo. Phn cui ca chng ny s trnh by ccbc lp k hoch cho QLTHCT v tho lun ngn v trt t QLTHCT.

1.1. Phi kt hp cc chin lc qun l cht thi

Phi kt hp cc chin lc qun l cht thi b sung thm cc phng nqun l cht thi cho cch qun l truyn thng l ch thu gom ri chn lp.Gim ngun thi, ti s dng, ti ch, lm phn hu c v thu hi nng lng lcc chin lc chuyn dng vn ng cht thi ra khi bi chn lp do tng

tui th ca bi chn lp v gim chi ph c v kinh t ln mi trng trongqun l cht thi. Phi kt hp cc chin lc chuyn dng ny vo trong quyhoch qun l cht thi l c s xc nh nhu cu v nng lc thu gom chtthi v tui th ca bi chn lp. Thu hi nng lng t thiu t cht thikhng ch n thun l sn xut nng lng m cn lm gim bt khi lngcht thi phi chn lp ti 90%. Tuy vy, thu hi nng lng khng phi l

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phng n kh thi v kinh t v v k thut khi m cn c mt t l cht thihu c ln trong ngun thi. Bi v cht thi hu c c m cao, gy kh khn

cho vic thiu t. Bng 1.1 l v d minh ho v thnh phn cht thi hu c Vit Nam.

Gii phpchin lc

Gim ngun thi

T i s dngTi ch

Lm phn huc

Thu gom

Thu hi nnglng

Chn lp

Cc bn lin quan

Chnh ph

Cng nghipCng ng a phng

Cc t chc qun chng

Khu vc phi chnh quy

Cc t chc cng ng

Cc t chc phi chnh ph

Cc kha cnh

X hi

Kinh t

Php lut

Chnh tr

Th ch

Mi tr

ngCng ngh

Qun l tng hp cht thi

Bn

vngv

kinht

Bn vngv mi trng

Bnv

ngv

xhi

Hnh 1.1.Qun l tng hp cht thi.

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Khi hot ng sn xut, kinh doanh pht trin v mc tiu dng gia tng, tl giy v nha trong cht thi cng s tng ln ng k. Khi cc phng php

thu hi nng lng nhsn xut kh sinh hc t cht thi hu c cn c nghincu p dng.

Bng 1.1.Thnh phn cht thi rn mt s th Vit Nam nm 2002

Thnh phn

cht thiH Ni Hi Dng

Thnh ph

H Ch Minhng Nai

Hu c 49.5% 46,6% 60,1% 71,4%

Cht tr 19.0% 27,7% 17,1% 5,7%

Giy 1.9% 5,8% 5,4% 6,2%

Nha 14,9% 3,4% 3,1% 8,6%

Kim loi 6,38% 4,9% 1,24% 1,2%

Thy tinh 6,9% 1,2% 4,1% 6,2%

Cao su, da 0,6% 5,8% 3,2% 3,2%

Cht thi nguy hi 0,5% 1,4% 1,3% 0,1%

Khc 0,4% 3,2% 4,4% 2,3%

Ngun: C c b o c o hin trng mi trng ca c c S Ti nguyn vMi trng n m 2003.

Gim ngun thi c ngha l gim c lng thi ln mc c hi cacht thi ti ngun pht thi. Gim ngun thi trong cng nghip bao gm gimlng thi trong qu trnh sn xut. V d, mt ngnh cng nghip s dng than sn xut nng lng trong qu trnh sn xut c th gim lng trothan thira bng cch chuyn sang s dng cc thit b tit kim nng lng. Gimngun thi trong cng nghip cng bao gm c vic sn xut sn phm to tcht thi khi s dng chng.

H gia nh c th gim thi ti ngun lc h mua sn phm to t chtthi hn khi s dng v khi thi b. V d, mt h gia nh c th la chn giahai sn phm tng t, trong mt sn phm vi t gi bc hn th s la chnsn phm t bao b s gip gim pht thi.

Mt gii php chin lc thc y gim ngun thi trong cng nghip lthc hin chng trnh sn xut sch hn. Sn xut sch hn gip cng nghip

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nhng cch thc lm tng hiu qu kinh t trong qu trnh sn xut ca mnhthng qua gim nhim ti ngun. Cc gii php chin lc khc bao gm p

dng mt mc ph cao i vi vic chn lp cht thi ti bi chn lp, k c vicp dng trch nhim m rng ca ngi sn xut l mt cch thc i hi ccnh sn xut cng nghip c trch nhim x l cht thi t sn phm ca h (thd nhmy vi tnh hay xe t) m ngi tiu dng thi b.

Cc gii php chin lc thc y h gia nh gim ngun thi c th tptrung ch yu vo gio dc v suy ngh hnh ng v vic lm th no gimpht thi trong quyt nh mua hng ca h.

Ti s dng, ti ch v lm phn hu c l nhng thut ng ng ngha vivic gim ngun thi.Ti s dngl s dng li sn phm hay vt liu m khngc s sa i ng k. Chng ch cn lm sch hoc sa cha trc khi s dng

li.Ti chkhc vi ti s dng ch n i hi s bin i nhiu hoc ch binnht nh v vt l, ho hc hay sinh hc. Ch bin phn hu cl mt dng cati ch cht thi bi v trong qu trnh phn cc qu trnh sinh hc bin icht thi hu c (thng l thc n v rau qu) thnh phn bn hu c giu dinhdng. Mc d phn hu c c hm lng dinh dng khng cao nhphn hohc nhng n rt hu ch nh l b iu tit cht mn cho sn xut nngnghip.

Vit Nam hot ng kinh t khng chnh thc, v d nhhot ng canhng ngi thu mua cht thi l cc vt dng c th ti s dng hoc ti ch.Mt c tnh v ng gp kinh t ca khu vc khng chnh thc Hi Phng

cho thy gi tr vt liu ti ch thng phm y l vo khong 2,1 triu USD(tng ng 30,152 t VND) vo nm 2000. Cc vt liu ti ch thng phmbao gm giy, kim loi, nha v thu tinh. Mt iu tra khc c tin hnhnm 1996 H Ni (DiGregorio et al. 1997) a ra con s 6.000 lao ng cthu nhp t cng vic thu mua cht thi cho ti ch v ti s dng. Nghin cuny c tnh hot ng khng chnh thc ny gim khong 20-25% lngcht thi cho cc bi chn lp, tc vo khong 80.000 tn cht thi mi nm.Mt li ch kinh t b sung quan trng t hot ng khng chnh thc ny lgim bt chi ph ca chnh quyn thnh ph cho vic thu gom cht thi.

Mc d khu vc khng chnh thc hin ang hot ng tt trong lnh vc

thu gom cht thi, nh

ng cc gii php chin l

c nhm thc y ti s dng vti ch vn cn tnh n nhm vo m rng v h tr pht trin hot ng ny,nhgio dc ngi dn hiu bit v li ch mi trng ca vic ti s dng vti ch cht thi, thc hin cc chng trnh phn loi cht thi ti ngun thnhloi hu c v loi v c. Phn loi cht thi ti ngun c th gip cho vic thumua cht thi ca hot ng kinh doanh khng chnh thc tt hn. S phn loi

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ti ngun loi cht thi hu c ca cc h gia nh cng gip ch cho ccchng trnh ch bin phn hu c bi v n em li li ch nhiu hn so vi

vic ch bin phn hu c t ngun cht thi cha c phn loi.

0

2,000

4,000

6,000

8,000

10,000

12,000

P

milliondong/year

lastics Paper Metals Glass Others

Triung/nm

Nha Giy KnhKim loi Loi khc

Ngun: JICA (2001)

Hnh 1.2.Gi tr vt liu ti ch thng phm Hi Phng, 2000.

Cc gii php chin lc thc y ti s dng v ti ch trong cngnghip c th bao gm h tr v th ch vic trao i cht thi cng nghip. Bncnh vic tha nhn chnh thc v s ng gp ng k ca khu vc kinh tkhng chnh thc, s h tr c th thng qua cung cp tn dng nh cho hotng ca nhng ngi lao ng thu mua cht thi.

1.2. Phi kt hp cc kha cnh x hi, kinh t, lutphp, chnh tr, th ch, mi trng v cng nghtrong qun l cht thi

Phn ln cc hot ng trong qun l cht thi l cc quyt nh v cngngh, ti chnh, lut php hay cng ch thi hnh, pht hnh chnh. Tt c cchot ng ny cn c phi kt hp vo trong cc quyt nh v qun l chtthi. V d, khi la chn a im xy dng bi chn lp, s l khng y khich xc nh a im ny v l do t tn km. Ngi qun l cht thi cn xc

nh c tc ng mi trng tim tng ca mi a im, tc ng x hi ivi ngi dn a phng v c s ng h ca h i vi a im xut lachn. Cc cng ngh chn lp cng phi l ph hp cho vn hnh v nng lcth ch phi tin hnh nh gi tc ng mi trng i vi bi chn lpv quan trc v vn hnh c hiu qu.

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1.3. Phi kt hp kin v u tin v phi kt hp cungcp dch v ca cc nhm lin quan

Rt nhiu c nhn, tp th v t chc s b nh hng bi cc quyt nhv qun l cht thi. Qun l tng hp cht thi phi tm hiu cc kin v tng ca cc bn lin quan b nh hng khi hoch nh v p dng cc giiphp chin lc, hay cc d n v qun l cht thi rn. Phng php tmhiu rt a dng, c th l cc hi tho, cc cuc hp cng khai, cc cuc iutra nghin cu, phng vn, hot ng ca cc ban thm nh, ban tvn. Lngnghe v hnh ng vi cc u vo nhvy khng ch gip hon thin thitk cc chng trnh hay d n qun l cht thi, m cn lm tng nhn thc vto s ng h ca mi ngi b tc ng nh hng i vi cc chng trnh

hay d n .

Hp 1.1.Cch ngh "khng sn sau nh ti" (NIMBY), bi chn lpv phi kt hp ca cc bn lin quan

Hu ht cc nc trn th gii u phi i mt vi s phn i cangi dn a phng khi tin hnh la chn hoc l vn hnh cc bi chnlp mt a phng no do quan nim ph bin ca cng ng khng sn sau nh ti. Vit Nam cng khng phi l mt ngoi l. Quan imkhng sn sau nh ti rt ph bin bi v ngi dn a phng phi chucc tc ng xu v mi trng (mi, ting n, rc, nhim nc, ruimui,) do vic thit k v qun l cc bi chn lp yu km. Thc tin tiuhy cht thi khng an ton v nhn thc v mi trng ca ngi dn chac nng cao l nguyn nhn ca cc trng hp khng sn sau nh ti Vit Nam.

Mt trong nhng cch gii quyt vn ny l thc hin nh gi tcng mi trng mt cch nghim tc trc khi ph duyt d n xy dngbi chn lp; cn nhc k lng cc kin ca tt c cc bn lin quan, cbit l nhng ngi dn a phng trong cc giai on lp k hoch v qunl.

Ngun: Bo co Din bin Mi trng Vit Nam 2004 - Cht thi rn

Kha cnh th hai ca phi kt hp cc bn lin quan l nhu cu v phikt hp trong cung cp cc dch v qun l cht thi. Vic cung cp cc dch vny c th bao gm s cng tc, hp tc ca cc t chc cng ng, khu vc phichnh quy, khu vc tnhn v chnh quyn thnh ph, hoc tng t chc ny cth hot ng c lp. Tt c cc bn lin quan ny c th h tr nhau v cc

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Bng 1.2.Ba v d v x hi ho dch v thu gom cht thi H Ni

c tnh Phng Minh Khai,

Huyn T LimPhng Thnh Cng,

Qun ng aPhng Nhn Chnh,

Qun Thanh Xun

Dn s (ngi) 1.200 10.000 18.000

Nm bt u 1999 2000 1996

T chc qun l Ban qun l ph. Minh

Khai (BQLMK)

HTX v sinh mi

trng Thnh Cng

T thu gom cht thi

rn Nhn Chnh

C cu qun l i din t chc

cng ng v 3 hi

vin Hi ph n

Phng Minh Khai

Ban iu hnh gm 16

thnh vin i din

ca UBND a

phng, S KHCNMT,Hi Ph n; b phn

hnh chnh c 6 ngi

UBND a phng

ch nh 3 t trng

dn ph phng

Nhn Chnh

Ngun nhn lc

t thu gom

Hi ph n a

phng

Ngi dn a phng Hi ph n a

phng

Ngun chi tr

trang thit b thu

gom v cc hot

ng

Ban qun l phng

Minh Khai

Cng ty MT th

cung cp trang thit b

v tr lng cho ngi

thu gom; UBND a

phng chi tr cc

khon khc

Cng ty MT th

cung cp xe thu gom

rc lc ban u; T

thu gom cht thi rn

Nhn Chnh chi tr

cc trang thit b

khc (k c xe thu

gom rc ln tip

theo) v cc chi ph

hot ng

Tn sut thu

gom

2 ngy 1 ln hng ngy hng ngy

Ph thu gom

(tnh trn 1

ngi/1 thng)

300 VND (1999)

400 VND (2001)

500 VND (2002)

1.000 VND 1.000 VND

T l thu c 98% 65% 70%

Ngi thu Nhn vin Ban qun

l phng Minh Khai

Ngi thu gom Ngi thu gom

Ni tp kt

rc thi

Bi rc a phng Bi chn lp rc

H Ni

Bi chn lp rc

H Ni

Ngun: Richardson (2003)

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dch v v lm tng hiu qu cung cp dch v ni chung. Vit Nam, nhni trn, khu vc khng chnh thc gip gim bt mt phn ng k lng

cht thi ch n chn lp cc bi chn lp, lm gim khi lng cht thi m

cng ty mi trng th phi thu gom, chuyn ch, chn lp. Mt chin lc

x hi ho trong qun l cht thi ang c thc hin c kt qu nhiu a

phng Vit Nam cng l biu hin ca s phi kt hp cc bn lin quan

trong qun l cht thi, vi s t chc h thng thu gom cht thi 2 tng, l: cc

t chc ca cng ng thu gom cht thi ca cc h dn v tp trung cht thi

thu gom nhng im gom nht nh; cng ty mi trng th s m nhn

vn chuyn tip cht thi t cc im gom ti bi chn lp. Bng 1.2 l mt vi

v d v chng trnh thu gom cht thi da vo cng ng.

1.4. Lp k hoch qun l tng hp cht thi

Lp k hoch qun l tng hp cht thi bao gm 7 bc:

Bc 1: Xc nh i tng. bc ny s xc nh bn cht v phm vivn qun l cht thi v xc nh cc bn lin quan b nh h ng ly

kin tvn, tham kho trong mi bc tip theo.

Bc 2: Cng c nhn thc v cc nhu cu i vi cht thi cn c

qun l v xc nh thnh phn cht thi, trong c cht thi nguy hi cn cthit b qun l c bit.

Bc 3:Xc nh v nh gi tnh bn vng v kinh t, x hi v mi

trng ca cc gii php chin lc chuyn dng cht thi tim nng.

Bc 4: Ci thin cc dch v thu gom cht thi. bc ny cn lu rng cc gii php chin lc chuyn dng cht thi c th lm gim nhu cu v

thu gom mt s loi cht thi hoc c th i hi cc dch v thu gom khc

nhau nhdch v thu gom cc vt liu c phn loi ti ngun.

Bc 5: Kim tra vic tin hnh thu hi nng lng bng thiu t haybng phng php khc nhphng php sn xut kh sinh hc, c thch hp

hay khng. Quyt nh v s ph hp ny s da vo thnh phn cht thi, s c

sn kinh nghim s dng cng ngh, tc ng mi trng ca cng ngh v tnh

bn vng v kinh t ca xut p dng.

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Bc 6: Xc nh cc a im d kin bi chn lp v cc trang thit b

qun l vi cc tiu ch v kinh t, x hi v mi trng, la chn a im v

thit k thit b chn lp hp v sinh.

Bc 7: Thit lp cc ch s (indicators) v kinh t, x hi v mi trng

theo di, quan trc c tt c cc thnh phn ca h thng qun l cht thi.

Bc ny cng bao gm c vic xc nh k hoch quan trc v nh gi thng

xuyn tnh hiu qu v bnh ng ca h thng qun l cht thi. Tnh hiu qu

l h thng ny to ra thnh qu hoc tc ng mong mun nhth no. Tnh

bnh ng l hng vo phn b cng bng cc li ch v chi ph gia cc bn

lin quan.

Bng 1.3.Khung cu hi vi 7 bc thc hin lp k hochqun l tng hp cht thi

Bc 1: Phm vi, i tng

a. Nhm vo loi cht thi no?

- Tt c cc loi?

- Cht thi cng nghip?

- Cht thi gia nh?

- Cht thi th?

- Cht thi thng mi?

b. Phm vi thi gian qun l?

- 10 nm?

- 20 nm?

- 50 nm?

c. Ai l cc bn lin quan b nh hng v h c th c huy ng tham gia vo vic lp

k hoch v qun l nhth no?

- Chnh quyn trung ng?

- Chnh quyn a phng?

- Chnh quyn c s?

- Cc t chc thu gom cht thi?

- Ngnh cng nghip?

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- Dn c?

- Ngi nht rc v thu mua cht thi?

- Cc t chc cng ng v phi chnh ph?

Bc 2: Thnh phn cht thi v pht thi

C nhng g trong cht thi v pht thi bao nhiu hin nay v trong thi gian ti?

Bc 3: Gii php chin lc chuyn dng thi

a. Lm th no gim thi ti ngun?

b. Lm th no thc y ti s dng?

c. Lm th no thc y ti ch?

d. Lm th no h tr lm phn hu c v u, nhth no?

Bc 4: Gii php chin lc thu gom cht thi

Lm th no ci thin dch v thu gom cht thi?Bc 5: Gii php chin lc thu hi nng lng

Bc 6: Gii php chin lc chn lp

Chn lp cht thi u v nhth no?

Bc 7: Quan trc v nh gi

Nhng ch s (indicators) no l thch hp i vi vic quan trc h thng QLTHCT v

vic nh gi tnh hiu qu v cng bng ca h thng ny c tin hnh thng xuyn

ra sao?

Qu trnh lp k hoch QLTHCT nu trn gi nh rng cc c quan qun

l cht thi c nng lc thc hin cc vn t ra mi bc. Nu nng lcny khng th phi c s o to hoc ngun lc cn thit cho vic xy dngnng lc.

1.5. Xc nh trt t trong QLTHCT

Cn phi dnh u tin nhth no cho mi chin lc nu bng 1.3?.Cu hi ny tng l i tng ca nhiu cuc tranh lun trong cc hi thokhoa hc. Hin nay mi ngi u bit mt cch tng th l i vi cc nccng nghip ho cao th s u tin hay trt t ca cc chin lc phi bt u tgim thiu ti ngun hoc trnh to cht thi t nh ca thp trt t v kt thcbng chn lp y thp (xem hnh 1.3.). Ni cch khc, cc nh qun l chtthi phi a nhng g quan trng nht vo k hoch gim thiu cht thi tingun v ch sau khi cc chin lc khc pht huy ht kh nng th mi tnhn vic a lng cht thi cn li i chn lp ti bi thi. Nhng lun c khoahc r rng minh chng cho cc li ch v mi trng ca trt t ny. Lun

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hnh 1.4. ta thy 2 trt t QLTHCT xut cho cc nc ang phttrin. Trt t th nht do Van de Klundert v Anschutz (2002) xut rt ging

vi trt t i vi cc nc cng nghip ho cao. Th nhng cc tc gi khc,nh Schubeler (1996) li gii thiu mt trt t khc v xut l chin lcqun l cht thi quan trng nht cc nc ang pht trin phi l thu gom ttc cht thi pht sinh ti ch bi v mc thu gom c th l rt thp ccnc c thu nhp thp. Cht thi khng c thu gom c th gy nguy hi ngk cho mi trng v sc kho. Schubeler cng thy rng ci thin thc t chnlp phi l chin lc u tin hng u bi v phn ln cc phng tin chn lp cc nc ang pht trin l cc bi chn lp l thin gy hi ti mi trng.Ngay c Van de Klundert v Anschutz cng nhn thy rng trong nhng honcnh nht nh th trt t qun l cht thi truyn thng do h xut phi cthay i hng vo cc vn c th cc nc ang pht trin: "Cngging nhmi chnh sch, trt t cn phi c p dng vi s linh hot nhtnh. i khi ti ch li khng hn l gii php ng v cc gii php khc nhthiu t li c th l thch hp hn ... nhtrong trng hp cht thi y t" (Vande Klundert v Anschutz 2001: 16).

1.6. Kt lun

Qun l tng hp cht thi ang c chp nhn rng ri v l cch tipcn thn mi trng trong qun l cht thi. Lp k hoch cho QLTHCT cn

nhiu thi gian hn so vi cch lp k hoch qun l cht thi truyn thng, bi

v cn phi cn nhc kin ca cc bn lin quan v mi quan h gia cc chinlc qun l cht thi khc nhau. Tuy vy, kt qu thu c li l xng ng vi

cng sc b ra. Cc chng tip theo trong cun sch ny s cp ti cc kha

cnh khc nhau ca QLTHCT v trnh by cc trng hp nghin cu vQLTHCT c p dng nhth no v c th cn c tip tc hon thin ra

sao Vit Nam, Campuchia, Lo v cc nc Chu khc.

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Ti liu tham khoBeigl, P. and Salhofer, S. (2004). Comparison of Ecological Effects and Costs of

Communal Waste Management Systems. Resources, Conservation and Recycling 41:

83-102.

DiGregorio et al. (1997). Linking Community and Small Enterprise Activities with Urban

Waste Management: Hanoi Case Study. WASTE, Urban Expertise Program, Gouda,

the Netherlands.

Finnveden, G. and Ekvall, T. (1998) Life-Cycle Assessment as a Decision-Support Tool

the Case of recycling Versus Incineration of Paper. Resources, Conservation and

Recycling 24: 235-256.

Finnveden, G., Johansson, J., Lind, P., and Moberg, A. (2005) Life Cycle Assessment

of Energy from Solid Waste part 1: General Methodology and Results. Journal of

Cleaner Production 13(3): 213-229.

JICA (2001) The Study on Sanitation Improvement Plan for Haiphong City in the

Socialist Republic of Vietnam, Final Report.

Moberg, A., Finnveden, G., Johanson, J. and Lind, P. (2004) Life Cycle Assessment of

Energy from Solid waste part 2: Landfilling Compared to other Treatment Methods.

Journal of Cleaner Production 13(3): 231-240.

Richardson, D. (2003) Community-Based Solid waste Management Systems in Hanoi,

Vietnam. Unpublished Research Paper, Faculty of Forestry, University of Toronto

Schbeler, P. (1996) Conceptual Framework for Municipal Solid Waste Management in

Low-Income Countries, UMP Working Paper Series 9.

USEPA (United States Environmental Protection Agency) (1999) Environmental Fact

Sheet: Source Reduction of Municipal Waste. USEPA, Washington

http://www.epa.gov/epaoswer/non-hw/muncpl/pubs/envfact.pdf

Van de Klundert, A. and Anschutz, J. (2001) Integrated Sustainable Waste

Management the Concept. WASTE, Gouda, the Netherlands.

Wilson, E.J. (2002) Life Cycle Inventory for Municipal solid Waste management, part 2:

MSW Management Scenarios and Modeling. Waste Management and Research 20:

23-36.

23
http://www.epa.gov/epaoswer/non-hw/muncpl/pubs/envfact.pdfhttp://www.epa.gov/epaoswer/non-hw/muncpl/pubs/envfact.pdf


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2

c im cht thi rn

Virgina Maclaren

2.1. Gii thiu

Nghin cu c im ca cht thi c tin hnh nhm xc nh khi

lng v chng loi pht sinh t mt s ngun c la chn v mt s c

im khc ca cht thi v d nh m, nng lng v thnh phn ha hc.

Tt c cc c im trn ng vai tr rt quan trng i vi nhiu lnh vc khc

nhau trong qun l cht thi. Bit c khi lng cht thi pht sinh l bao

nhiu, v d mt th, s gip chng ta xc nh c s lng v kch c

cc loi phng tin cn thit thu gom cht thi v tui th ca cc bi chn

lp. Bit c thnh phn cu to ca cht thi c th gip chng ta xc nh

hoc loi b cc phng thc x l cht thi ph hp v khng ph hp. V d,

nu cht thi c hm lng hu c cao th ch bin phn compost s l phngphp thch hp x l. ng thi, nu hm lng hu c cao th vic thiu t

s khng hp l v phng php ny i hi nhiu nhin liu. Trong chng ny

chng ta nghin cu s bin i ca qu trnh pht sinh cht thi v thnh phn

cu to ca cht thi theo khng gian v thi gian, ng thi tho lun v cch

nh lng v d on khi lng v thnh phn ca cht thi.

2.2. nh ngha cht thi

Cht thi l g? Cht thi l mt vt khng cn gi tr, c v gi tr

kinh t v "gi tr s dng". Mt vt c th khng c gi tr v mt kinh t vkhng c th trng tiu th sn phm v sn phm hay vt khng bn

c, nhng n vn c th c gi tr s dng bi v n c gi tr tinh thn ivi mt ngi no hoc v h khng kh nng mua mt vt khc c

cht lng tt hn thay th ci m h ang c.

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Mt vt c coi l b i i vi mt ngi no vn c th l c

gi tr i vi ngi khc. Chng hn, ti ni lng qua s dng m mt h gia

nh thi ra c th l ngun thu nhp i vi nhng ngi thu gom cht thi.

2.3. Cht thi rn th

Cht thi rn th bao gm cht thi t cc khu dn c, khu vc bun

bn thng mi v khu vc cng nghip. N c th hoc khng bao gm cht

thi xy dng v cht thi t vic p ph cc cng trnh xy dng c. Trong

nhiu vn bn php lut, cht thi rn cn bao gm cht thi cng nghip khng

nguy hi. Thng thng, cc cng ty mi trng th chu trch nhim thu

gom cht thi th nhng i khi vic thu gom vn do cc cng ty tnhn

theo hp ng hoc t chnh quyn a phng m nhim (c gi l thu gom

cht thi trn c s cng ng).

2.4. Cht thi nguy hi

Cht thi nguy hi c th pht sinh t nhiu ngun khc nhau nhng hu

ht chng c ngun gc t khu vc cng nghip. Nhng ngun pht sinh cht

thi phi cng nghip bao gm h gia nh, cc c quan v cc khu bun bn,

thng mi. Cc cht thi nguy hi l nhng cht c th gy nguy him cho con

ngi hoc cc t chc sng khc v cc cht thi ny c tnh cht c hi, n

mn, d chy n, d gy phn ng hoc c tnh cht bnh l. Cht thi c hi

c th gy t vong hoc thng tch nghim trng khi ht th, n v hp th.

Tnh cht ha hc ca cc cht thi c tnh cht n mn c th ph hy vt liu

v cc m trong c th ngi im tip xc. Cn cc cht thi bnh l rt

nguy hi v chng c kh nng ly lan bnh tt. Theo nh ngha, cht thi

phng x cng l cc cht thi nguy hi nhng chng thng c phn thnh

mt loi ring v chng c cc c tnh ha hc ring bit v tc phn hychm (Maclaren 2004). Do nguy c gy tc hi i vi con ngi v mi trng

nn cc cht thi nguy hi cn c tch ring khi cc loi cht thi khc

cng trit cng tt v cn c chuyn n cc c s x l cht thi nguy hi

chuyn bit.

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2.5. Cc lung cht thi tri ngc

Cht thi pht sinh t mt ngun nht nh c gi l mt lung chtthi. C t nht 4 im khc bit c bn gia cc lung cht thi c nh hng

n vic la chn chnh sch qun l cht thi. Th nht l khc bit v chtthi pht sinh thnh th so vi cht thi pht sinh nng thn. Cht thi th

thng c t cht hu c hn v nhiu loi bao gi v cht thi vn phng hn

khu vc nng thn. V d, nm 2003 Vit Nam, 24% dn s ca c nc sng khu vc thnh th, tuy nhin b phn dn s ny thi ra hn 50% (khong hn

6 triu tn) tng lng cht thi th ca c nc. iu ny l do i sng

cng cao th cc hot ng thng mi, bun bn cng nhiu v tc cngnghip ha cc khu vc th cng mnh m hn. Cc hot ng nh vy

cng lm tng t l cht thi nguy hi (v d nhpin, c quy v dung mi docc h gia nh thi ra) v cc cht thi khng phn hy c (v d nhnha,kim loi v thy tinh). Tri li, ngi dn khu vc nng thn thi ra ch mc

gn bng mt na t l ca cc h gia nh khu vc thnh th (0,3kg/ngi/ngy so vi 0,7 kg/ngi/ngy, v hu ht cht thi nng thn (99%

cht thi canh tc v 65% cht thi gia nh so vi 50% cht thi gia nh t cc

th) l cht hu c (Bo co din bin mi trng Vit Nam 2004).

Mt tng phn quan trng khc gia cc lung cht thi l s khc

bit gia cht thi sinh hot v cht thi t khi cng nghip - thng mi - vn

phng (ICI). Cc lung cht thi sinh hot c tnh cht ng nht hn v thnhphn cu to so vi cht thi ICI. khu vc dn c, ch c mt loi ngun pht

sinh cht thi duy nht l cc h gia nh, trong khi khu vc th ng mi

cht thi pht sinh t 3 loi ngun ch yu: vn phng, cc ca hng bn l vcc nh hng. Mi tiu khu vc c mt loi cht thi chim a s: giy ln

trong cc vn phng, thc n tha trong cc nh hng v bao gi trong cc cahng bn l. Mt khc bit na gia khu vc dn cv khu vc thng mi

l vic xc nh khi lng tiu chun trn u ngi trong pht sinh cht thi

khu vc dn cc hiu l cht thi pht sinh trn 1 h dn, cn khu vc ICIth con s ny thng c tnh bng khi lng cht thi pht sinh trn 1 nhn

cng. Cc mc pht sinh cht thi trn mt nhn cng s bin i ty theo loihnh hot ng thng mi v s nhn cng.

Khu vc thng mi, khi c quan, vn phng c kh nhiu loi hnh hot

ng, v d nhcc c quan vn phng Nh nc, thvin, trng hc v cc

thit ch vn ha. Cht thi ca khu vc ny cn bao gm cht thi khng nguy

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hi t cc bnh vin. Giy l thnh phn ch yu ca lung cht thi trong 3

ngun u tin, tuy nhin ngun cn li c rt nhiu lung cht thi khc nhau.

Lung cht thi cng nghip thm ch cn phc tp v khng ng nht

hn so vi cc lung cht thi khi vn phng v thng mi. Bng 2.1 di y

minh ha s bin i ng k trong thnh phn cu to cht thi ca 3 ngnhcng nghip ca Vit Nam. Kt qu cho thy, sn xut nng lng t than thi

ra phn ln khi lng cht thi, trong khi , kim loi li c hm lng cao

nht trong ngnh cng nghip sn xut thp, cn cc cht hu c th c t trngcao nht trong khi lng cht thi ca ngnh cng nghip giy v bt giy, cn

cht thi vi c t trng cao nht trong ngnh cng nghip dt may.

Bng 2.1.Thnh phn cu to cht thi rn camt s ngnh cng nghipVit Nam

Thnh phn

cu to cht thi

Giy v bt giy

(n=16)

Dt may

(n=29)

Thp

(n=7)

Hu c 21,1 5,5% 0%

Mui than, t v 74,8% 67,7% 79,0%

Kim loi 0,7% 0,5% 20,0%

Vi si, giy, thy tinh 1,4% 22,2% 0%

Cc vt liu khc 2,1% 4,1% 0,1%

Ngun: MOI et al 2003.

2.6. Khc bit v mt a l trong pht sinh cht thi vthnh phn cu to cht thi

Khi lng pht sinh pht sinh cht thi cc nc c thu nhp tht

thng c xu hng thp hn so vi t l cc nc c thu nhp cao hn. iu

ny l do cc nc c thu nhp cao, sn xut cng nghip nhiu hn (v dovy nhiu cht thi cng nghip pht sinh hn), v ngnh thng mi v dch v

cng ln th mc tiu th v bao gi sn phm cng cao. Biu hnh 2.1 so

snh t l pht sinh cht thi trn u ngi trong 1 ngy ca 3 thnh ph ng

Nam so vi thnh ph New York. Cc s liu chi tit v thnh phn cu to

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v pht sinh cht thi mt s nc ng Nam c trnh by trong cc bo

co ca Ngn hng Th gii v Vit Nam (Ngn hng Th gii cng mt s tc

gi khc, 2004), Philippin (Ngn hng Th gii 2001) v Thi Lan (Ngn hng

Th gii 2003).

0

0.5

1

1.5

2

2.5

3

Ho Chi

Minh

City

Bangkok Hong

Kong

New

York

City

kg

per

capita

Hnh 2.1.Pht sinh cht thi th trn u ngi

trong mt ngy mt s thnh ph.

Tp.

kg/

ngi

Ngun: Ngn hng Th gii v cc tc gi khc (2004), Ngn hng Th gii (2003), S Bo

v Mi trng Hng Kng (2003)m, S V sinh Thnh ph New York (2003).

Thnh phn cht thi ca cc nc c thu nhp thp v cc nc c thu

nhp cao cng c nhiu khc bit. nhng nc c thu nhp cao, t l cht thi

thp hn cc nc c thu nhp thp v trong cht thi ca cc nc c thu

nhp cao c nhiu bao gi v giy ln hn. V d nh Canaa, lng cht thi

th trung bnh t cc khu vc thnh th bao gm 40% cht thi hu c (Nin

gim Thng k Canaa 2005). Vit Nam, khi lng cht thi hu c trung

bnh trn ton quc khu vc thnh th l 55% v khu vc nng thn l 60 -75% (Ngn hng Th gii v cc tc gi khc, 2004).

Mt nguyn nhn khc dn n s thay i trong thnh phn cht thi ca

khu vc thnh th chnh l ngun pht thi. V d, trong biu hnh 2.2, cht

thi c cy v g c t l cao hn trong lung cht thi th so vi lung thi

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sinh hot (theo nghin cu v thnh phn cht thi ca th Manila). Tng t

nhvy, t l nha thu gom c t mu cht thi sinh hot cao hn t l nha

trong lung cht thi th Manila (Nghin cu v thnh phn cht thi ctin hnh trn cc mu cht thi ly t 60 h gia nh, 10 ca hng bn l, 5 vn

phng hoc c quan, 2 khu ch v cht thi thu gom c trn 2 tuyn ph).

0% 10% 20% 30% 40% 50%

Other

Grass and wood

Food waste

Glass

Plastic

Paper

Textiles

Leather and rubber

Municipal

Residential

Hnh 2.2.Khc bit v thnh phn cht thi gia cht thi th

vcht thi sinh hot th Manila, Philippin.

Cc loi cht thi khc

Cy c v g

Thc phm

Thy tinh

Nha

Giy

Dt may

Thuc da v cao su

Cht thi th

Cht thisinh hot

2.7. Cc nghin cu v c tnh cht thi

Mc ch ca nghin cu v c tnh cht thi l xc nh lng cht

thi pht sinh trong mt b phn dn cnht nh v thnh phn cht thi, v

thng xc nh theo trng lng ch khng phi khi lng. Nghin cu v

c tnh cht thi cn c th cung cp cho chng ta cc c tnh v nhng c

im ca mt lung cht thi, v d nh m, nng lng v thnh phn ha

hc.

Ph

ng php khoa hc kh thi nht tin hnh phn tch thnh phncht thi l "ly mu v phn loi" hoc phn tch trc tip cht thi. Vi

phng php ny, ngi nghin cu phi ly mu i din ca cht thi t mt

b phn dn cnht nh, phn loi chng thnh cc chng loi khc nhau, xc

nh trng lng ca cht thi mi loi v sau tnh ton t l phn trm trong

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tng s cht thi ca mi mu i din cho mi loi. Cc nh nghin cu ang

tranh ci kh gay gt v khi lng cht thi bao nhiu l c th lm mu

i din. C 2 tc gi Tchobanoglous (1993) v Martin (1995) cng ng s

xut khi lng tiu chun lm mu l 90 kg cho mi mu. V t l phn

trm ca mi thnh phn trong lung cht thi l khc nhau, do c 1% sai

s c mu vi 95% khong tin cy, s mu trng lng 90 kg cn c xc

nh mi thnh phn sau y ca mt lung cht thi i vi giy, 35 i vi

kim loi, 19 i vi thy tinh v 13 i vi nha. Vic gim c mu hoc c ca

mi mu s lm gia tng sai s c mu.

Nhng khuyn ngh trn s ph hp nht cho vic lp mu cht thi hn

hp ti cc bi rc hoc cc im trung chuyn. Vic lp mu cht thi ti cch gia nh cn mt hng dn khc, bi v khi lng cht thi do mi h gia

nh sn sinh ra thp hn nhiu so vi mu 90 kg. V d t hnh 2.1, lng cht

thi bnh qun u ngi ti thnh ph H Ch Minh l 1,24 kg mt ngy. V

th s lng mu cht thi ly ti cc h gia nh cn nhiu hn t c s

chnh xc. Mt s nh nghin cu (nhAbu Qdais v ng s, 1997, Bolaane

v Ali 2004) s dng cng thc chun sau tnh c ca mu:

N = (Z x S/E)2

Trong N l c ca mu, Z l ch s Z cho phn phi chun, thngthng lin quan n mc xc sut nh trc (v d Z = 1,96 i vi mc xc

sut 95%), S l lch tiu chun ca mu v E l li sai s chn mu. Vic lp

mu phi c thc hin trong vng t nht 7 ngy lin ly c s bin i

theo tun, v t nht mt nm 2 ln thy c s khc bit gia cc ma.

Khi lng cht thi c tnh khi cn t, tc l c cn trc khi c lm

kh, t nhin hoc nhn to.

Trong nghin cu v thnh phn cht thi c nhiu cch phn loi. Cch

ph bin nht c s dng trong cc nghin cu thnh phn cht thi l nghin

cu tng qut. Cch phn loi in hnh ca hnh thc nghin cu tng qut l

phn loi theo nguyn liu, c th hin trong ct u tin ca bng 2.2. Cht

thi cng c th c phn loi theo loi sn phm, nhtrong hnh 2.2. Ch

tiu ch "cht thi hu c" l ch loi cht thi nhthc n tha hay l, hoa ho,

c sau khi lm vn. Mc d giy cng l mt nguyn liu hu c, n vn c

lit k trong mt loi ring.

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Bng 2.2.Cc v d v vic phn loi cht thi

Theo loinguyn

liu

Theo sn phmv loi nguyn

liu

Theo loi sn

phm

Theo loi

nguyn liu

ng gi

Theo kh nng

ti ch

1 2 3 4 5

Cc sn phm

nb

Cc sn phm

khng bn

Thy tinh Nguyn liu ti

ch

Giy v ba

cc tng

thy tinh

Kim loi Bo V ung Bo

Kim loi Thp Sch v Tp ch V thng cha Ba cc tng

Thp Nhm Giy vn phng Thp Tp ch

Nhm Kim loi Giy n V hp Giy vn phng

Cc kim

loi phi st

khc

Thy tinh Cc v a giy Cc ng

gi bng thp

khc

Cc loi giy khc

Nha* Nha Cc v a giy Nhm PET, HDPE, v

cc cht do ti

ch khc

PET Cao su v da Ti ng rc lm

bng cht do

V hp Thic

HDPE Bng si t

nhin

Qun o v tt L kim loi Thy tinh mu v

Thy tinh trong

sut

LDPE Vi Khn tm, khn

tri ging v v

gi

Giy v ba

cc tng

Nhm

PS Cc loi khc Cc sn phm

bn

Ba cc tng

nhn

Cc kim loi khc

PP Cc sn phm

khng bn

Cc dng c

chnh

Cc hp v

hp cc tng

khng ti ch

c

PVC Giy v ba cc

tng

Cc dng c

ph

Ti ng v ti

xch

Giy sp

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1 2 3 4 5

Cc loi

nha khc

Nha c, gia

dng

Giy gi Giy nha

Cao su v

da

Cao su v da Thm Nha E Ti nha

Vi dt Vi dt Lp xe V chai PS v cc cht

do khng th ti

ch c

G Cc loi khc Pin Ti ng v ti

xch

Tro bi ng gi v

dng

Cc thit b in

t

Giy gi cht

do

n tha

L, c, hoa

tt c cc

loi cht

thi khc

Kim loi

Thp

Nhm

Thy tinh

G

Hp g

Tm g

Giy, ba cng

Nha, G

Cc loi khc

Ngun: Theo US EPS (2005) * PET = polyethylene terephthalate, HDPE = cht do

polyethelylene mt cao, LDPE = cht do polyethylene mt thp, PS = polypropylene,

PVC = polyvinyl chloride.

Vic chn hnh thc phn loi cht thi th hin cch thc qun l cht

thi c th. V d, nu mc ch ca vic nghin cu phn loi thnh phn cht

thi l quyt nh tnh ph hp ca mt ngun thi cho vic lm phncompost th c th phn loi theo ba tiu ch sau: cht thi hu c d chuyn

thnh phn compost, cc cht thi hu c khc (nhg), v cc cht thi v c.Loi cht thi hu c d chuyn thnh phn compost c th tip tc c chianh thnh cc cht hu c c hm lng cacbon cao v cc cht hu c c hm

lng nit cao. Vic phn loi nh nhvy rt c ch cho mc ch lm phn

compost bi v hot ng compost ny ph thuc vo t l cacbon/nit (C/N),

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thnh cng th t l ny cn phi mc t 20:1 n 25: 1 hoc cao hn mt

cht (theo Hoornweg et al, 2000). Cc cht hu c giu cacbon bao gm rm,

mn ca v v bo. Cc cht hu c giu nit gm cc loi rau qu v rc thcvt (Tchobanoglous et at, 1993).

Nu mc ch ca vic phn loi cht thi l xc nh khi lng chtthi c th ti ch c th phn loi thnh hai nhm sau s ph hp nht: loicht thi c th ti ch v loi khng th ti ch. Tuy nhin quyt nh u lnguyn liu c th ti ch v u l nguyn liu khng th ti ch cn ph thucvo nhu cu ca th trng cho sn phm ti ch . Loi cht thi c lit vodanh sch c th ti ch cng khc nhau trong tng thi k v ty tng ni biv th trng ti ch v gi tr ca hng ti ch cng khc nhau theo thi gian vty tng ni. V d, mc d cng ngh ti ch ti nha c sn ti Bc M song

khng c th trng cho sn phm ti ch ny ti y. Trong khi ti ngNam th trng cho sn phm ti nha ti ch kh ln, v ni ny vn s dngthit b cng ngh thp v lc lng lo ng r, khin cho ngnh ny tr thnhmt ngnh thu c li nhun t gi nhn cng thp. Nhng r rng l chtlng ca sn phm ti nha ti ch l rt thp v gi kh r v nhu cu ca snphm vn cn. Nhu cu ny s thay i theo thi gian nu ngi tiu dngng Nam i hi loi ti nha c cht lng cao hn.

0%

10%

20%

30%

40%

50%

60%

Organic Ash anddirt

Paper Plastic Glass Metal

Higher income

Lower income

Hnh 2.3.S khc bit trong thnh phn cht thi theo mc thu nhp

ca cc h gia nh ti Bc Kinh, Trung Quc.

H c thunhp cao

H c thunhp thp

Thy tinh Kim loiNhaGiyTro vbiHu c

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Khi lp mu cht thi t h gia nh, cn p dng bin php phn lp lymu theo mc thu nhp ca h gia nh bi v cc nghin cu tr c y cho

thy vic thi rc v thm ch thnh phn cht thi thng c xu hng phthuc vo mc thu nhp ca tng gia nh. Hnh 2.3 minh ha s khc bit nyti thnh ph Bc Kinh. Cc h gia nh c thu nhp thp s dng nhin liuch yu l than v vy sn sinh ra lng tro x kh ln. Trong khi cc hgia nh kh gi dng ga lm cht t nn khng c tro, nhng h thi ra nhiucht thi l ng gi hn, nhti giy, nha, v thy tinh.

2.8. Kt lun

Chng ny trnh by vic thi v thnh phn cht thi thay i theo

ngun pht thi, mi nc, mi thnh ph v theo mc thu nhp ca tng h gianh. Chng ny cng cp n vic lm th no tnh ton khi lngv thnh phn cht thi. R rng l khi so snh cc nghin cu v pht thi vthnh phn cht thi trn c nc hoc trong cc thnh ph cn phi nhn nhnxem cc nghin cu c hng v mt i tng hay khng, c dng cngmt phng php nghin cu hay khng v c ngun pht thi tng t nhauhay khng.

i liu tham khoAbu Qdais, H. A., Hamoda, M. F. and NewhaAm, J. (1997) Phn tch chtthi rn sinh

hot ti ngun thi. Nghin cu v qun l cht thi 15: 395-406

Bolaane, B. and Ali. M, (2004) Ly mu cht thi sinh hot ti ngun: bi hc kinh

nghim xxxxxx. Nghin cu v qun l cht thi 22: 142-148

S v sinh th New York (2003) thnh ph New York, Khi qut mhnh k hoch

qun l cht thi rn mi

Hng Kng, Cc bo v mi trng (2003) Mi trng Hng Kng 2003. Cc bo v

mi trng Hng Kng

Hoornweg, D. and Thomas, L. (1999) Cht thi ph phm: Qun l chtthi Chu ,

Ngn hng Th gii, Washington, D. C.

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Hoornweg, D. Thomas, L. & Otten, L. (2000). Sn xut phn Compost vkh nng ng

dng cc quc gia ang pht trin. Ban Pht trin th, Ngn hng Th gii,

Washington, D. C.

Maclaren, V. W. (2004) Qun l cht thi: Phng php tng hp. Bruce Mitchell (ed.)

Qun l v pht trin ngun lc Canada, ti bn ln 3. Nh xut bn trng Oxford,

371-397

Martin, J. H., Collins, A. R., and Diener, R. G. (1995) Cng thc lymu cho sn xut

phn Compost, ti ch vs dng cc cht thi rn aphng. Tp ch Hip hi qun

l khng kh v cht thi 45: 864-870

B Cng Nghip (BCN) Hip Hi Dt May (2003). Pht trin bn vng vk hoch bo

v mi trng khu vc dt may ti nm xxxxx.BCN, H Ni

B Cng Nghip (BCN) Vin Giy v Cellulose (2003). Pht trin bn vng v k

hoch bo v mi trng khu vc ngnh giy ti nm 2010. BCN, H Ni

B Cng Nghip (BCN). Tng cng ty Thp Vit Nam (2003). Pht trinbn vng vk

hoch bo v mi trng ngnh thp ti nm 2010.BCN, H Ni

Shimura, S., Yokota, I., v Nitta, Y. (2001) Nghin cu phn tchlng qun l cht thi

rn cc quc gia ang pht trin. Chu trnh qun l nguyn liu v cht thi 3: 48-59

Thng k Canada (2005) Mi tr

ng v

h

nh vi ca con ng

i. Thng k Canada, Ottawa

Tchobanoglous, G., Theisen, H. v Vigil, S. (1993) Qun l tng hpcht thi: Cc vn

qun l vc s k thut. McGraw-Hill, New York

M : C quan bo v mi trng (US EPA) (2005) Cht thi rn th,ti ch v x l

M: Thc trng nm 2003. US EPA, Washington. C th truy cp tm hiu ti:

www.epa.gov/msw/msw99.htm

Ngn Hng Th Gii (2003) Bo co din bin mi trng Philippines:Cht thi rn.

Ngn Hng Th Gii, Manila

Ngn Hng Th Gii (2003) Bo co din bin mi trng Thi Lan 2003:Cht thi

rn. Ngn Hng Th Gii, Bangkok

Ngn Hng Th Gii, B Ti Nguyn Mi trng. C quan hp tc pht trin quc t

Canada (2004) Bo co din bin mi trng Vit Nam: Chtthi rn. Ngn Hng Th

Gii, H Ni.

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3

Gim thiu cht thi, phn loi, Thu gomvx l cht thi rn t ngun pht sinh

Nguyn Quc Cng

3.1. Thu gom s cp v phn loi cht thi rn tingun pht sinh

3.1.1. Khi nim chung

Thu gom cht thi rn ti ngun pht sinh l qu trnh thu nht rc (haygi chung l cht thi rn) ngay trong cc h gia nh, khch sn, cc cng s,trng hc hay trong nhng trung tm y t, dch v thng mi, x nghip cngnghipTip theo, nu ti cc nh , cng s hay cc n v trn ng c lpth c th lu gi, x l ti ch, cn nu th, khu cng nghip th bc chng

ln xe v ch n a im x l, chuyn tip, trung chuyn hay chn lp. X lcht thi gn ngun pht sinh l kh thi v i hi ngi ch cht thi t phnloi trc khi em ti ni tp trung. Vic lm ny c nhiu li ch m trc htl gim c chi ph kinh t v mi trng khi vn chuyn v chn lp cht thi.

Vic thu gom cht thi rn thng chia ra thnh cc cng on s cpv th cp. S phn bit ny c hm l nhiu khu vc, vic thu gom phic thc hin theo mt qu trnh hai giai on: thu gom cht thi t cc nh v thu gom tp trung v ch cha trung gian ri t li chuyn tip v trmtrung chuyn hay khu x l v bi chn lp. chng ny s tp trung trnhby cc vn v phn loi ti ngun pht sinh v thu gom s cp . Vic phnloi ti ngun v thu gom s cp nh hng trc tip i vi con ngi, mquan cng nh hiu qu ca cc cng on vn chuyn v x l, s dng hayti ch sau .

Phn loi ti ngun pht sinh c hiu l cc loi cht thi cng loi,cng gi tr s dng, ti ch, hay x l, c phn chia v cha ring bit. Vd, thng thng, ti mi h gia nh hay cng s, mi n v, cht thi nhcc

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loi can, hp, chai l c th cha trong mt thng hay ti nha mu vng, loigiy hay sch bo, cc tng c cha trong mt thng hay ti nha mu xanh;

loi bao gi thc n hay thc n d tha c cha trong thng hay ti nhamu en.

Thng th cc h thng phn loi, thu gom s cp bao gm nhng thngcha, xe ch rc loi nh, xe hai bnh ko bng tay thu gom rc v ch n ccbi cha chung hay nhng im chuyn tip. Do vy, vic phn loi v thu gomban u c ngha rt quan trng trong mi h thng qun l cht thi rn nichung, trong vic thu gom v vn chuyn th cp tip theo. n lt mnh victhu gom th cp li ph thuc vo cc loi xe ti thu gom c la chn, voh thng v cc phng tin thu gom ti ch.

Khi thu gom rc thi t cc nh hay cng s thng t tn km hn so

vi vic qut dn chng t ng ph. Bi v vic c th gim th tch hoctrng lng cht thi, d dng ti s dng hoc ti ch nhng vt liu hu ch

ln trong cht thi, tit kim thi gian nht rc v qut dn ng ph khuyn khch cng ng thc hin cn phi c nhng im cha trung gian

nhng khong cch thun tin cho nhng h to rc v chng cn c quy

hoch, thit k sao cho rc thi c a vo thng cha ng ng v tr, ddng v to iu kin thun li cho thu gom th cp. Chng ny s tp trung

vo cc hot ng lin quan ti phn loi, gim thiu cht thi h gia nh ti

ngun, k thut thu gom s cp v hai s la chn cho x l cht thi phn tn.

3.1.2. Thu gom cht thi rn t trong h gia nh (thu goms cp)

Trong h thng ny, cc h gia nh c th tham gia hoc khng cn thamgia vo qu trnh thu gom. Nhng ngi thu gom rc s i vo tng nh (snhay vn), mang thng rc ra vo xe ca h v sau tr v ch c. Chi phtrong h thng ny ch yu ch yu cho nhn cng lao ng. Tuy nhin, nhng nc c thu nhp thp, gi lao ng thng kh r nn hnh thc nytng i tt.

Mt dng khc ca hnh thc ny l nhng ngi thu gom rung chung

hay g ca tng nh v i ch nh mang rc ra ca. Phng php ny c ththu c hu ht cht thi ca h gia nh nhng tn nhiu nhn cng v thigian i thu gom cht thi.

Trong phm vi ti liu ny, thut ng nh thp tng c s dng ivi nhng ngi nh c s tng nh hn bn. Thut ng nh cao tng c

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s dng i vi nhng ngi nh c s tng ln hn by. i vi nhng nh cs tng t bn n by c xem l nhng nh c cao trung bnh. Vic thu

gom ti ch l ton b nhng hot ng c lin quan ti thu gom cht thi rn ti khichng lu gi trong cc cngten trc khi c vn chuyn bng cc phng tin thugom bn ngoi.

Thu gom t cc nh thp tng

Ngi nh hoc ngi thu c nhim v qut dn v gom rc vo thng

cha hay cc ti ng bng nha. Vic tp trung v thu gom cht thi cc khunh ny thng l t nht mt ln/ngy. Lng rc to thnh thng dao ng

nhiu v c kh nng ti ch. Lu rng lng cht thi rn theo u ngi

trong nm s rt t nhng ni thc hin tun hon dng li cc loi cht thi

(thu tinh, giy, kim loi...) [3].Thu gom t cc nh trung v cao tng

i vi nh loi ny, mi cn h phi c thng hay ti cha nh v

ngi thu gom rc a xung di tng di hoc vo cc ng ng

vo b cha. Tin b hn, ngi ta p dng cng ngh gom rc ch yu bngcc ng ng h thng kh nn.

i vi cc nh trung tng, cc ng ng thi rc thng c tit din

trn, vung hoc ch nht, bng thp, b tng hoc xy gch. ng knh 300 600mm, thng thng 500 600 mm. S thu gom rc thi t cc nh trung,

cao tng c th hin hnh 3.1 v 3.2.i vi cc nh cao tng th h thng phc tp hn v c cu to nh

sau:

- Ca rc

Ca rc ca h thng ng dn rc ca nh cao tng c thit k

theo ng qui cch v thm m ca nh cao tng cng nhnhng trung tmgiao dch ln. Cht liu ca ca c ch to bng thp chu nhit v c ph

ln mt lp mu ph hp vi mu ca cng trnh (lp sn tnh in), m

bo khi chy trong ng th nhit khng lan ra ngoi theo ng rc (trong

vng 120 pht).- ng thot kh

ng thot kh c ni vi ng ng chnh. Trn ng thot kh ca h

thng ng dn rc ca nh cao tng c lp mt qut ht to ra chn

khng v thong kh cho mng rc. ng knh ngoi ca ng thot kh l

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230mm, c lm bng cht liu nhh thng ng dn rc ca nh cao tng

vi tt c tnh nng k thut ca h thng ng . ng ng thot kh c

ko di v cao hn mi t 0,7m ti 2m.

- ng ng dn rc ca nh cao tng:

ng ng dn rc ca nh cao tng c b mt bn trong nhn, m bokhng b vng mc khi rc thi ri trong ng ny.

Hnh 3.1. S thu gom rc thi t cc nhtrung, cao tng.

ng phi c thit k m bo chng n, m, n mn v c ch to

bng vt liu c bit, trit tiu c m thanh do rc thi to ra trong ng. ngny thi cng rt n gin, gn nh khng phc tp, vt liu ch to nh rt ph

hp vi nh cao tng.

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Ngoi ra ng ny phi m bo khica ct rt d dng thun li cho thi cng lp

t ca rc...Trong h thng t hp vn chuyn rc

theo chiu ng th ng ng ng thu rcl quan trng nht.

Kch thc ng dn rc trung bnh l600 - 900 mm. Nu cc thit b ch bin(my p rc, l thiu rc...) c gn lin ving dn rc th ngi lm dch v ch vicchuyn tro v rc nn n bi rc.

- ng ng nghing

ng nghing c gn vi ng ngbng h thng ai ghp ni, nghing cang so vi trc ng ng l 350. ngnghing c gn vi ca x rc.

- Ca x rc

y l h thng ca m t ng bngtrng lng c lin kt vi h thng itrng, khi trng lng rc y ca xrc th h thng ny s t ng m ra (nhh thng i trng) rc c x n thng

rc.- Cc b phn khc

+ Qut ht: m bo cho h thngc kh rc, thng thong khng b mi khi rc. Qut ht l loi qut in 1 pha, cngsut 40W tr ln.

+ Chp thu: Chp thu l thit b linkt gia ng rc chnh v ng thot kh.

+ai c nh: ai c nh bng thpc chc nng gi cht ng v c nh ng

vi sn nh bng vt n st.+ ng ph thu rc : L ng lin kt

gia ca rc v ng ng ng chnh.Khi , rc s c i qua ca rc ri quang ph thu rc v vo ng chnh.

Hnh 3.2. Chi tit h thng

thu gom t cc tng

1.ng ng;

2. ng nhnh tip nhn rc

3. Ca np rc;4. Thng cha rc;

5. Ca thm vty sch;

6. Chp thng hi.

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+Epoxy:L cht liu gn mng thu rc vi ng ng chnh.

+ ng rc:Trong mt s trng hp, ngi ta lp thm on ng rc ti cui ng ng chnh. ng ny c ng knh 630mm, vi di 4 m.

Nhng yu t quan trng nht cn c xem xt khi xy dng mt dchv thu gom s cp bao gm :

-Cu trc hnh chnh v qun l i vi dch v;-Cc tiu chun ca dch v s c a ra;-C quan chu trch nhim thu gom (chnh quyn thnh ph, x nghip,

c quan trong thnh ph, nhng ngi nht rc, cc gia nh)

-a im thu gom (t cc gia nh, t l ng, t bi rc cng cng)-Loi xe thu gom s c s dng-C cung cp cc thng cha rc hay khng ?-H thng cha v kiu, kch thch, vt liu ca thng rc s c s

dng;

-Liu s phn loi ti ngun cc vt liu dng li c c kh nng kinht khng v cn phi c cho php.

-Tn sut thu gom.3.2. Lu gi cht thi rn ti ngun

3.2.1. Cc phng tin lu, cha ti ch

Dung tch trung bnh ca phng tin thu cha c quyt nh bi sngi trong nh, s lng nh c phc v v tn sut thu gom rc thi. Dungtch trn c tnh ton vi mc thi rc 0,5 0,8 kg/ngi/ngy [3]. C ccloi phng tin thu cha sau :

Ti ng rc khng thu hi: Ti c lm bng giy hoc bng cht do,nhng ti lm bng cht do cn c cc khung kim loi ti khi rcvo, cn ti bng giy th cng hn. Kch thc v mu sc ca ti c tiu

chun ho trnh s dng ti rc vo mc ch khc.Thng ng rc: Thng ng rc thng dng thng lm bng cht do.

Dung tch loi dng trong nh 5 10 lt; loi dng ti c quan, vn phngthng t 30 75 lt, i khi 90 lt. Thng phi c np y. Nhn chung kch

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thc ca cc loi thng rc c th c la chn theo quy m v v tr thngcha.

- Thng rc trong nhc s dng cha rc thi trong nh v ca ra ngoi vo thi im c nh trc ;

- Thng rc bn ngoil nhng thng cha ln hn t bn ngoi nh v bn l ng khi ch thu gom.

- Thng ng rc s dng khi thu gom bng cc phng tin y kn rc. l cc thng ng rc c np vo bn l mt h thng moc c th rc bng my vo trong xe qua mt ca c bit. Dung tch thng th ng t110 160 lt v thng lm bng cht do.

- Thng ng rc di ng :Thng ng rc bng st hoc bng cht do,

c np y lp vo bn l. di chuyn c d dng, cc thng ny c ttrn cc bnh xe; 2 bnh xe nh c nh i vi loi thng nh v 4 bnh xexoay c cho loi thng ln. Mt h thng moc cho php rc bng myvo xe thu rc. C 3 c : c nh 500 lt, c va 750 lt, c ln 1000 lt. Gm c2 loi :

-Loi thng dng cho nhng loi rc thi c khi lng trung bnh0,15 kg/l.

-Loi bn chc cho nhng loi rc thi c khi lng trung bnh l0,4kg/l. Loi thng rc ln thng dng thng c s dng trong nhng khunh cao tng.

Cc loi thng rc c thit k khc nhau c th c s dng cha rcti cc khu nh hay nhng khu c mt dn ccao nhnhng khu chungc. Cng c th thit k nhng im thu gom cng cng m rc thi c trc tip vo nhng thng cngten c t bn trong im thu gom, mi gianh u nhng thng rc ca h vo im thu gom ny. Vic ny to iukin thun li cho bc trc tip rc thi vo nhng xe thu gom th cp, gip chogim bt bc d bng th cng.

Cc nguyn tc thc t khi la chn hay thit k mt h thng cha rcthi bao gm :

- Chn cc vt liu ca a phng, vt liu dng li, hay c sn : ikhi thit k mt loi thng rc c dng v hp dn v ng nht li c th lmthay i ng k cch rc ca qun chng v nh hng n thi ca h.Vic s dng thnh cng nhng thng mu xanh bng vt liu dng li BcM kch thch v thc y s chp nhn cc vt liu dng li v lm tng tl thu li t 20% ln ti 75% mt s ni [3].

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- Chn thng cha d dng nhn thy, bt k bng hnh dng, mu schay nhng du hiu c bit : y cng l mt u im ch r mt loi

thng, cha ng nht khi bt u a vo mt h thng thu gom mi, v iuny ni ln tnh chnh thc ca thu gom v a thm tm quan trng vo schp nhn. Ngoi ra, nu cc thng ny l d dng nhn ra th iu ny cng cth c mt phn vai tr chng trm cp.

- Chn cc thng cng d sa cha hoc d thay th : iu ny l cnthit i vi tnh lu di ca h thng thu gom v mt tin cy ca h thngv chi ph. cng l cn thit m bo rng cc thng cha s khng b githi bay i mt hay d b b qua do nhng ngi bi rc hay sc vt bi.

- Chn loi thng m khng ngn cn nhng ngi bi rc : Nu nhngngi bi rc cm thy kh khn khi tm kim, h c th s lt c thng ra

v lm cho rc vng vi ra ph, do vy th tiu mt mc ch ca thng rc.- Xem xt vic nhn din thng rc theo cc ch nhn bng a ch, tn

hay m s. i khi tn v a ch trn thng rc li mang li mt thc tt hnv trch nhim v c xu hng gi cho thng rc c sch v/hoc ly v ngaykhi im rc sau khi ht.

- Chn thng rc ph hp vi a hnh. Chn loi c bnh xe nu lnhng ng ph c lt phng, bng vt liu khng thm nc nu cma nhiu, bng vt liu nng nu hay c gi mnh

- Ch to thng rc bng nhng vt liu khng hp dn k trm. Thng

c s lo lng l cc thng rc nu

c

a ra rt c th s b n trm. C thgim thiu s ri ro mt trm ny bng vic ch to nhng thng rc bngnhng vt liu khng c gi tr, v d nhloi nha khng ti sinh c.

Nhn chung, cc phng tin thu cha rc phi tho mn cc tiu chunsau :

-Chng s xm nhp ca sc vt, cn trng.-Bn, chc, p v khng b hhng do thi tit.-D c ra.Phng tin lu cha rc cho cc to nh thng l cc thng kim loi (c

nh); b cha rc hoc c h rc. Mt s thng cha rc vn t trn ngph v ni cng cng hin nay hu nhkhng c rc trong, s d nhvy l vngi dn rt ngi khi vt rc vo thng li phi dng tay nng np y thngln. Khi thit k cc loi thng cha rc vn loi ny phi tho mn cc yu cusau :

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Bng 3.2.Cc thun li v bt li ca tng phng thcthu gom, lu gi ti ch

Phng thc Thun li Bt li

1 2 3

Khu dn cvthng mi

- Cht ng D dng i vi dn Mt v sinh. Km m quan

v ri vi bi nhng ngi

nht rc.

- Kho cha c nh

(xy bng gch)

Gp nhm cht thi thu

gom

i hi s ng gp t

nguyn ca dn. Mt thi

giam khi chuyn giao. Km

m quan v ri vi bi nhng

ngi nht rc.

- Ti cht do V sinh, ly nhanh, t phi

qut.

i hi phi thu gom tng

nh.

Dn phi mua tiBc kn cc cht thi.

- Bc cng nh Kinh t v c th ti sinh,

thu nhanh hn. Khng phi

qut

i hi phi thu gom tng

nh. C mi, cc thng cha

d b mt cp, phi lau chi

thng xuyn.- B cha cht thi Dn d s dng. Tp trung

cht thi(nhiu h gia nh)

Kh thc hin vic thu gom

c phn loi i vi b mt

ngn. Kh khuyn khch.

S dng khng c hiu qu.

- Cngten Gp nhm cht thi. Thu

gom v vn chuyn d

dng.

i hi s ng gp t

nguyn ca dn. Phi c

khng gian. Km m quan

v ri vi bi nhng ngi

nht rc.

(nhiu h gia nh v cc

cht thi xy dng)

ng cng cng

- Thng rc nh c nh D s dng cho ngi qua

li

C kh nng trn y.

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Tip bng 2

1 2 3- Xe y c nh 350 lt Thu gom v vn chuyn

d dng

Km m quan. D b ph

hoi.

- Cngten Gp nhm cht thi. Thu

gom v vn chuyn d

dng.

Xa nh . Khng c nhiu

khng gia. Km m quan.

Ri vi bi nhng ngi nht

rc.

C quan vx nghip

- Kho c nh Gp nhm cht thi Mt thi gian khi vn

chuyn.

- Cngten Gp nhm cht thi. Thugom v vn chuyn d

dng.

Phi c sn khng gian.km m quan.

Vic s dng cc loi ti nha i hi phi ng vin mnh m dnchng c s thay i ln cc thi quen ca h.

Cc b cha cht thi cc khu dn cnhiu h gia nh cng c pdng thnh cng nhiu nc phng Ty. Tuy nhin, cc ni dn cng

c, cn phi b tr xy dng cc b lu gi hai ngn to iu kin cho vic

phn loi cht thi, nng cao gi tr ti s dng li hoc ti ch.

3.2.4. Cc bin php gim lng pht sinh cht thi rn

Khi lng rc sinh ra ti cc ngun x ngy cng ln, v vy vic gimkhi lng cht thi rn l vn i hi x hi phi gii quyt vi mc tiu lu

di ph hp vi tnh hnh pht trin v bo v mi trng, bo m cn bng

sinh thi.

Hin nay, nhu cu sinh hot ca dn chng ngy cng cao, s lng chtthi ngy cng tng v do vy c nhiu s c xy ra trong qu trnh qun l cht

thi rn to thnh v xu th nh hng ca chng ti mi trng thin nhin

ngy cng tng. Giai on u ca vn gim lng cht thi l phi nhnthc c rng cht thi rn l loi cht thi khng mong mun, khng bit

trc c qu trnh trao i ca n trong vng v nhng tc ng do chng

gy ra mang tnh x hi. Cch la chn tt nht gim thiu lng cht thi vng thi gim thiu nhim. Khi s

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1. Tit kim nng lng v cc ngun nng lng gc;

2. Gim s khai thc ti nguyn, gim cc ngun gy tc ng xu timi trng;

3. Tng cng sc kho cng nhn v m bo an ton cho h do vic

hn ch tip xc vi cc vt liu c tnh c hay nguy him;

4. Gim chi ph khng ch nhim v qun l cht thi (chi ph ny ang

tng rt nhanh hn c t l tng sn phm cng nghip) v kh nng

mc phi trong tng lai i vi cht thi c hi v nguy him.

gim lng cht thi pht sinh v gim nhim phi:

-Tng hiu sut s dng nguyn liu;-Thit k li cc quy trnh sn xut v sn phm sao cho s dng t

nguyn liu hn;

-Thit k v to ra cc sn phm t gy nhim v t c ngun cht thi;-Loi b s ng gi khng cn thit.p dng cng ngh sn xut sch hn. Mc tiu ca cng ngh ny l

hn ch s dng ti nguyn v gim thiu cht thi. Trong tng lai c th to

ra cng ngh hiu qu hn, to ra qu trnh sn xut mi, cng nhbo v v tis dng ngun ti nguyn thin nhin k c vic chuyn ho cht thi thnh

nng lng.

3.3. X l cht thi rn ti nh gia nh

Nhiu h thng thu gom rc nhng th c thu nhp thp u phi i

mt vi nhng kh khn trong vic thu gom v x l rc thi. gim bt cc

khu trong chu trnh thu gom, vn chuyn, tp trung, x l tc l gim chi ph,

sc lc, thi gian, tc l tng hiu qu trong qun l cht thi rn, ngi ta phi

p dng nhiu gii php khc nhau. Cc quy trnh x l n gin in hnh ang

s dng cc nc ang pht trin c th hin bng 3.3.

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Bng 3.3.Cc quy trnh x l ti ch in hnh

Cc quy trnh x l ti ch in hnh Qu trnh thc hin

- Rc c ng trn ph - Rc c phn loi v cha trong cc

thng cha u tin trong cc gia nh

trc khi ra ng hoc im thu gom

ven ng

- Rc c vun, thu gom v vo thng

rc trn ph

- rc thi trc tip t cc thng rc ring

vo xe rc hay vo nhng thng rc ch i

c (thng rc th cp)

- Rc thi c thu gom th cng v cht

vo nhng xe ch rc khng t

- Rc thi c chuyn trc tip khng qua

bc th cng vo cc xe thu gom th cp

(thu gom th cp)

- D rc bng th cng ti thi im trung

chuyn, phn loi v bc xc ln xe

ch i chn lp

- D rc bng c gii ti im trung chuyn

hoc chn lp. Nu l ti im chuyn tip

th d rc ra sn b tng v bc xc bng

c gii.

Cn thit phi c nhng bin php x l s b rc thi bng cc phngphp c th nhm gim th tch, ng nht kch thc cht thi rn, phn cc

hp phn nng ring nh ring to iu kin thun tin cho cc bc tip theo.X l s b cng nhm mc ch d vn chuyn v d x l.

3.1 X l s b bng phng php nn p

i vi cc to nh trung bnh v cao tng, qu trnh x l vn hnh i

vi cht thi t cc to nh ring bao gm : nn, m, t, nghin v to thnh

bt nho, hoc cng c khi nghin nh v phn loi nh cc nh t tng.

- m nn : gim dung tch cht thi rn, khi thu gom ngi ta thng

dng thit b m nn cc to nh ln. Thit b m nn c t u di

ng ng tng di cng. Cht thi sau khi ri xung y ng ng, ngi ta

dng t bo quang in hoc nt bm y rc cht thi rn n thit b mnn. Tu thuc thit k ch to thit b m nn, cht thi rn c th c nn

thnh kin v t ng xp ti vo thng kim loi hoc ti giy. Khi cc kin

c hnh thnh v thng hoc ti y th my m nn li t ng y i v c

th lp i lp li. S ca x l s b bng nn p c th hin hnh 3.3.

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a) Bt u chu trnh nn

b) Ko khi bung nn

Hnh 3.3. S x l s b

bng nn p.

c) Nn p trong thng

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3.3.2. X l ti ch cht thi rn bng phng php sinh hcti ch

l cht rc thnh ng, trong di tc dng ca xy v s hot ngvi sinh vt m qu trnh sinh ho din ra phn hu cht hu c thnh mn. yl phng php ph bin x l rc, to iu kin cho rc c phn hu binthnh mn, c th dng lm phn bn phc v trng trt. Trong cc ng rc,do kt qu ca qu trnh sinh ho, nhit c th t ti 60oC v hn na. Vinhit v cc yu t khc, cc vi khun ng rut khng to nha bo(thng hn, tiu chy, l) v trng giun s b tiu dit [4,5,6].

Cc yu t nh hng ti qu trnh bao gm : nhit , m, pH, hpphn nguyn liu Sau thi gian th cc mm bnh s b dit. Phng php

ny c ngh p dng x l cc b cht thi cho cc khu dn cc dintch khng nm trong khu vc trung tm th v cho cc x nghip ch binhoa qu, thc phm cng nhcc khu vc khc c to ra t l cao ca thnhphn hu c trong rc thi. Tu thuc iu kin cung cp xy cho qu trnh phn hu c, qu trnh c th din ra trong iu kin hiu kh hay ym kh.

Cc vi khun hiu kh i hi c xy tn ti. Chng tn ti t nhintrong t, cht thi v to ra CO2, nc v cht mn hu c m khng to rami kh chu. Cc vi khun hiu kh c th phn lm 3 loi:

- Vi khun a lnh: thch nghi vi nhit di 20o C

- Vi khun a m: thch nghi vi nhit 20o C - 40o C

- Vi khun a nng: thch nghi vi nhit trn 40o C

Ngi lm phn hu c cn phn loi cht thi t ngun tht tt, chunb vt liu v phi trn cc thnh phn vt liu sao cho t l Cc-bon v Ni-tthun li cho qu trnh v cht lng sn phm theo s tay hng dn; kimsot cht ch nhit , m, chng ngp ng nc ma v m bo thong khcho vi khun hiu khi hot ng tt trong qu trnh . Nu m bo c ccyu cu trn th sn phm phn hu c hiu kh s c cht lng tt, gi thnh hv khng to ra mi kh chu vi con ngi v mi trng [5,6] (Xem hnh 3.4a).

Bi rc (cnh ng rc) : Rc c khu vc ring bit. Trong

cnh ng ngi ta chia thnh cc khu vc ln lt rc.Nu tnh ton s b th 1000 dn cn 0,13 0,15 ha din tch , c trng

cy xanh cch li vi cc khu vc xung quanh [3,4].

H rc: Xy dng cc h rc ngoi tri, o trc tip di t. Tuynhin cn lu trnh gy nhim ngun nc ngm.

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B sinh hc : b c dung tch 5 15m3. tng hiu qu qu trnh ngi ta c gii ho khu np v ly rc ra ngoi. Qu trnh sinh ho trong b

ch yu nh s tham gia tch cc ca cc vi sinh vt hiu kh hoc ym kh tutin. tng cng qu trnh sinh ho trong b, ngi ta phi thc hin lmthong, thng hi tt v phi xy dng sao cho gi c nhit cao trong .

Hnh 3.4. S cu to ca mt s loi b sinh hc ti ch in hnh

ng sinh hc: to cc ng rc ngoi tri, s dng qu trnh sinhhc hiu kh t nhin phn hu cc cht thi hu c thnh phn trong iukin t nhin. Ngi lm phn theo cch ny cn quan tm vic m bo kchc ng thch hp, o trn v kim sot nhit v m ca ng v kimsot vn mi. H cng cn bo v ng khi cc sinh vt s c th o bing v trnh gy nhim ngun nc ngm.

V tr xy dng b , ng hoc h phi c s ng ca c quanv sinh dch t v qun l mi trng. S v hnh nh thc t ca mt s kiu sinh hc cht thi hu c c trnh by hnh 3.4; 3.5.

Trong tng lai, cc chng trnh lm phn nhiu h gia nh, cc cquan, trng hc s phi c thc hin phng php ny. Cn lu ti cc

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cht cn c lm phn cc c s x nghip, trng hc v lu ti vics dng cui cng cc sn phm .

Hnh 3.5 S b rc n gin quy m nh [3]

1-Tng b (trt va xi mng vnh mu)

2- Ca ly rc ra ; 3 H thu nc ;

4- Cp khng kh ; 5 - Ca rc vo thng ;

6-ng thng hi ; 7- Li tho ra c ;

8-ng thot nc.

Cc u v nhc im ca tng phng thc cht thi rn hu c ti

ch,

c trnh by tm tt bng 3.4.Bng 3.4. Cc uv nhc ca tng phng thc

cht thi rn ti ch

Phng thc u im Nhc im

- Lm phn

nh

Khng nh hng g ti mi trng. R tin.

Khuyn khch nhn dn v li ca phn

Cn c s ng h v

theo di

Ch p dng i vi

rc thi hu c

- Phn ti

ch, (nhiu h

gia nh)

C th p dng cho mt chng trnh mang

tnh cng ng nng cao gi tr khu dn c.

ng vin nhn dn bo v mi trng ca h.

Cn c s tham gia

ca dn.

Cn c khng gian

Gim chi ph v lp t

- Phn ti

ch (ti cc khu

cng nghip v

c quan)

Ngi s dng c dng nhng sn phm

ci thin ni tr ng ca mnh.

Cn khng gian.

Cn c s kim tra.

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3.3.3 Phng php thiu t

Phng php ny tuy chi ph cao, thng thng l 20 23 USD/tn,nhng chu trnh x l ngn ch t 3 4 ngy. V gi thnh t nn ch c ccnc pht trin p dng nhiu. cc nc ang pht trin nn p dng phngphp ny vi quy m nh x l cht thi c hi nh: cht thi bnh vin,cht thi cng nghip

Nh thiu t, dung tch cht thi rn c gim nhiu ch cn khong10% so vi dung tch ban u; trng lng gim ch cn 25% hoc thp hn sovi ban u. Nhvy s to iu kin thun li cho vic thu gom v gim nhucu v dung tch cha ti ch, ngay ti ngun, ng thi cng d dng chuynch ra bi chn lp tp trung nu cn. Tuy nhin, phng php t rc thi ti

ch s gy nhim khng kh cho khu vc dn cxung quanh, ng thi lmmt m quan th. V vy khng c b tr l t trong hoc gn khu dn c.Phng php ny cng c gi thnh t v c kh nng to ra nhim kh thiv tro bi nn khng ph bin rng ri cc nc ang pht trin nh VitNam. Tuy nhin n c th ch dng ti cc a phng nh, c mt dn sthp v thiu hu mt s lng hn ch cc cht thi nguy hi nhcht thibnh vin v cht thi cng nghip c hi.

Ngoi ra cn c cc k thut mi khc x l cht thi nhl v bo, vtru, mn ca em p lc cao vi keo tng hp lm thnh tm tng, trnnh, t, bn gh, hoc x l du cn dng li

3.3.4.X l cht thi rn ti cc c s thng mi vcng nghip

Cc hot ng x l ti ch cc c s thng mi v cng nghip cngtng t nhi vi cc nh c m t trn y. Tuy nhin iu quantrng i vi cc c s ny l vic phi nn p sao cho dung tch cht thi l tnht. iu c bit i vi cc c s cng nghip l cc qu trnh x l a dnghn.

Nn p ng kin

Ti cc c s thng mi, siu th, thng p dng gii php ng kin,

nn p cc loi bao gi cc tng. Kch thc cc loi bao gi rt a dng. Tuynhin a s thng l loi nh hnh 90x120x150 centimet. Do vy ngi ta cth ch bin thnh cc loi vt liu sn xut cc thng cha phc v cho vicchuyn ch cc loi hng ho trn cc tu bin.

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3.3.5. Thu gom cht thi rn phn chia ti ngun

Vic thu gom cht thi rn c phn chia ti ngun cn c thchin trc khi a i s dng li hay ti ch. Vic thu gom cc loi vt liu nycng c thc hin nhc m t chng 4 v chng 6.

i liu tham kho1. B Xy dng, 1999. "nh hng Quy hoch tng th th Vit Nam". NXB Xy

dng, H Ni.

2. B Xy dng, 1999. "Chin lc Quc gia v Qun l cht thi rn th vKhu

Cng nghip n nm 2020".NXB Xy dng, H Ni, 1999.

3.Trn Hiu Nhu, ng Quc Dng, Nguyn th Kim Thi - Qun l cht thi rn. Tp

1. Cht thi rn th. NXB Xy dng, H Ni, 2001.

4. George Tchobanoglous, Hilary Theisen, and Samuel Vigil, 1993. Integrated Solid

Waste Management: Engineering Principles and Management Issues. New York, Mc

Graw-Hill International Editions- Civil Engineering Series.

5. Murray Haight and Paul Taylor, 2000. A Manual for Composting in Hotels. CUC

UEM project, AIT, Thailand, First Edition August 2000.

6. Trn Hiu Nhu v Nguyn Quc Cng, 2005. Nghin cu th nghim qun l cht

thi rn hu c ca khu du lch Bi Chy, thnh ph H Long, Vit Nam.NXB Vn ho

Thng tin, H Ni, 2005.

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Thu gom, tp trung, vn chuyn

cht thi rn thTrn Hiu Nhu

4.1. Thu gom cht thi rn

Thut ng 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 mcn c vic chuyn ch cc cht thi ti a im tiu hu. Vic d cc xe

rc cng c coi l mt phn ca hot ng thu gom th cp. Nhvy thu gom

th cp l cch thu gom cc loi cht thi rn t cc im thu gom chung (imcu 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.

4.1.1. Cc khi nim

Quy hoch thu gom cht thi rnl vic nh gi cc cch thc s dngnhn lc v thit b tm ra mt s sp xp hiu qu nht. Mun vy cn xemxt cc yu t sau :

-Cht thi rn c to ra : S lng (tng cng v tng n v); t trng;ngun to thnh.

-Phng thc thu gom : Thu gom ring bit hay kt hp.-Mc dch v cn cung cp ; L ng; li i; khi nh-Tn sut thu gom v nng sut thu gom : S nhn cng v t chc camt kp; Lp l trnh thu gom theo tng khu vc; ghi chp nht k v bo co.-S dng hp ng thnh ph hoc cc dch v tnhn.-Thit b thu gom : Kch c; chng loi; s lng; s thch ng vi cc

cng vic khac.

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-Cc ngun lc : Gi thnh; th trng; thu gom; phn loi-Tiu hu : Phng php; a im; chuyn ch; tnh php l.-Mt dn s : Kch thc nh ca; s lng im dng; lng cht

thi rn ti mi im; nhng im dng cng cng

-Cc c tnh vt l ca khu vc : Hnh dng v chiu rng ng ph;a hnh; m hnh giao thng (gi cao im, ng mt chiu)

-Kh hu : ma; gi; nhit -i tng v khu vc phc v : Dn c(cc h c th v nhng im

dng cng cng); doanh nghip; nh my.

-Cc ngun ti chnh v nhn lc.Dch v thu gom tp trung cht thi rn l vic kh khn phc tp v

nhng l do sau:

-Cc ngun to cht thi rn theo khng gian v thi gian;-Cht thi rn ngy cng gia tng v s lng v chng loi;-Gi thnh chi ph nhn cng v nhin liu ngy cng cao;Chi ph cho cng on thu gom, tp trung chim t 60 80% tng chi ph

thu gom tp trung x l v x cht thi rn.

Cc tiu ch chnh c trng cho hiu qu thu gom :

1. S tn cht thi c thu gom trong mt gi;

2. Tng s h c phc v trong mt gi lm vic ca mt kp;

3. Chi ph ca mt ngy thu gom;

4. Chi ph cho mi ln dng thu gom;

5. S lng ngi c phc v bi mt xe trong mt tun.

Cc loi h thng thu gom (bao gm hnh thc cng ng thu gom chtthi phng)

4.2. Cc phng thc thu gomThu gom theo khi : Trong h thng ny cc xe thu gom chy theo mt

quy trnh u n theo tn sut c tho thun trc (2 3 ln/tun hay

hng ngy). Nhng xe ny dng ti mi ng ba, ng t v rung chung.

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Theo tn hiu ny, mi ngi dn nhng ph quanh mang nhng st rc

ca h n vo xe. C nhiu dng khc nhau ca hnh thc ny c

p dng nhng im chung l mi gia nh c yu cu phi c thng rc caring mnh trong nh v mang n cho ngi thu gom rc vo nhng thi

im c quy nh trc. Trong mt s trng hp, chnh quyn thnh ph

cung cp nhng thng rc c tiu chun ho, mc d vn kinh ph chos tiu chun ho ny cn phi c xem xt mt cch cn thn.

Thu gom bn l ng : H thng thu gom ny i hi mt dch v u

n v mt thi gian biu tng i chnh xc. Cc cng nhn cn phi t li

thng rc sau khi c ht rc. iu quan trng l nhng thng rc ny

phi c dng chun. Nu khng s dng nhng thng rc chun th c th c

hin t

ng rc khng

c ht ra khi thng (th d nh

cc loi gi, hpcacton). Trong nhng iu kin ny, rc c th b gi thi hay sc vt lm

vng vi ra, do vy lm cho qu trnh thu gom tr thnh km hiu qu. nhng nc c thu nhp thp, hnh thc thu gom bn l ng thng khng

hon ton ph hp. Mt s vn thng ny sinh trong cch thu gom ny, vd nhng ngi nht rc c th s nhng thng rc ny ra nht trc,

thng rc c th b mt cp, sc vt lt hay b vt li trn ph trong mt

thi gian di.

4.3. H thng thu gom vn chuyn cht thi rn

4.3.1 Cc loi thit b tp trung vn chuyn cht thi rn

C th phn loi theo nhiu cch nh:

-Theo kiu vn hnh hot ng-Theo thit b, dng c c s dng nhcc loi xe ti c ln, nh-Theo loi cht thi cn thu gomTheo kiu vn hnh hot ng gm : H thng xe thng di ng (tch

ri), h thng xe thng c nh.

-H thng xe thng di ng (HT) l h thu gom trong cc thngcha y rc c chuyn ch n bi thi ri a thng khng v v tr tp kt

rc ban u. H thng ny ph hp vn chuyn cht thi rn t cc ngun to

ra nhiu cht thi rn, cng c th nhc thng rc y ln xe v thay bngthng rng ti im tp kt.

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-H thng xe thng c nh (HTC) l h thu gom trong cc thngcha y rc vn c nh t ni tp kt rc, tr mt khong thi gian rt ngn

nhc ln rc vo xe thu gom (xe c thnh xung quanh lm thng).

H xe thng di ng i hi phi c cc xe ti v trang thit b. Bng 4.1

trnh by h thng xe thu gom loi di ng.

Dng cc thng ln gim c thi gian bc d, v sinh hn so vi vicdng nhiu thng nh.

H xe thng di ng c u im l a dng v hnh dng v kch thccho nn c ng thch hp vi nhiu loi cht thi rn, thu gom c tng loi cht thi

rn.

Tuy nhin, vn c nh

c im l do cc thng ln v cng vic li th

ngphi thc hin bng th cng nn thng khng cht y c, do vy hiu qu

s dng dung tch km. Nu bc d bng c gii mi tn dng ht dung tch.

Bng 4.1.Cc h thng xe thng thu gom loi di ng

Loi xe Loi thng Dung tch

thng (m3)

- H xe thng vn chuyn di ng :

Xe nng (Hoisttruck) C b nn m c nh 5 10

Xe ko (tilt frame) sn nghingnng ln h xung t

Trn h gi l hp

C b nn c nh

C b c thng t nn

10 36

12 30

15 - 30

Xe c ti ko (truck-tractor) Trn h c ti ko 12 30

- H xe thng c nh:

My m nn bc d c gii

My m nn bc d th cng

Thng kn c b ti ko c trang b

b c thng t nn

15 30

Trn he v kn bc d pha trn 0,76 6

Thng nha hoc km loi m nh

ti giy hoc nilon kiu bao ti 0,05

- Xe nng: trc y c s dng ph bin trong thit b qun s, trong

cc x nghip cng nghip. N c th t nng v thu gom, tuy nhin c nhc

im v hn ch l ch s dng :

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- Thu gom cht thi rn t cc im ri rc v mt ni v l ng cht thi

rn l ng k.

- Thu gom cc ng cht thi rn hoc cht thi rn cng nghip m

khng dng cc xe c b nn c.

- Xe sn nghing (nng ln h xung) : h ny dng xe ti kiu y

nghing ln h xung vi cc thng ln - c dng thu gom mi loi cht

thi rn t ngun mi to ra. Bng 4.2 lit k cc loi thng ln i km vi loi

xe ny.

Cc thng h pha trn c dng hng ngy ni ph d hoc cng

trng xy dng. Cc thng ln thng km theo vi b m nn c nh dng

thu gom cht thi rn cc trung tm thng mi, cc cng trnh a nng, cc trm trung chuyn cht thi rn. V c dung tch ln v vn chuyn tt nn

loi xe thng nghing c dng rt rng ri.

Xe thng c ti ko: ging loi xe thng c sn nghing, dng rng ri

thu gom chuyn ch cht thi rn nhct, g x nh ca, mnh vn kim loi,

tc l dng cho vic ph d nh ca cng trnh (demolition).

H thng xe thng c nh v trang b : h thng ny c s dng rng

ri thu gom mi loi cht thi rn. Nhng h thng ny c s dng tu

thuc vo s lng cht thi rn cn thu dn v s im (ngun) to cht thi

rn.

H thng ny c 2 loi chnh:

+ H thng vi b nn v t bc d (c kh): thng vn chuyn cht

thi rn n khu tri, bi thi v sinh, trm trung chuyn hoc trm x l cht

thi rn.

Loi ny kh a dng v hnh dng v kch thc. Tuy nhin c nhc

im l khng thu gom c cc loi cht thi rn, cng knh nh c cng

nghip, cng trng xy dng, ph d cng trnh

+ H thng vi xe bc d th cng : loi ny ph bin dng chuyn

ch bc d cht thi rn cc khu nh . Loi bc d th cng c th hiu qu

hn so vi loi bc d c gii trong cc khu nh bi v lng cht thi rn

cn bc xp ri rc cc ni vi s lng t, thi gian xc, bc xp ngn.

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Bng 4.2. Cc loi thng ln i km vi loi xe vn chuyn cht kh

Kch thc, mmLoi xe

Thu gom

Dungtch

thng

hoc xe

ti (m3)

S

trc xe

Thnghoc xe

c dung

tch (m3) Rng Cao Di

Phng

php x

H xe thng di ng

Xe nng 5 10 2 8 84 80-100 110-150 Ri t do-

m

Xe sn

nghing

10 36 3 24 96 80-90 220-300 Ri t do-

ng

Xe ko

c ti

12 30 3 32 96 90-150 220-450 Ri t do-

nghing

H xe thng c nh, c trang b b nn c gii

Bc xp

pha trc

15 30 3 24 96 140-150 240-290 Nng

thu lc

Bc xp

pha bn

7,6-27 3 24 96 132-150 220-260 Nng

thy lc

Bc xp

pha sau

7,6-22 2 15 96 125-135 210-230 Nng

thu lc

H xe thng c nh, c trang b nn th cng

Bc xp

pha trc

7,6 28 3 28 96 132-50 240-300 Nng

thu lc

Bc xp

pha sau

7,6 22 2 15 96 125-135 210-230 Nng

thu lc

4.3.2. ngha kinh t ca hot ng trung chuyn v vnchuyn cht thi rn

Hot ng trung chuyn v vn chuyn cht thi rn bao gm cc ng

tc: cht thi rn - thng cha (hoc bn thn cc xe thu gom) - ch n ni tp

kt. Hot ng trung chuyn c th kinh t khi :

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-Cc xe thu gom nh bc xc th cng c dng thu gom cht thirn sinh hot v ch i xa;

-Lng cht thi rn nhiu phi ch i rt xa;-C trm trung chuyn vi mt s xe thu gom.

4.3.3. Nhu cu lao ng

Nhu cu lao ng tu thuc vo vic t chc thu gom v loi h thng xe

thu gom.

+H xe thng di ng : Nhu cu nhn lc ch cn mt ngi va li xe,

va cht y cht thi rn ln xe, va d cht thi rn ti bi chn lp. Tuy

nhin, an ton thng bin ch hai ngi (ngi li v ngi ph). Ngi lichnh c trch nhim vn hnh my, cho my hot ng Ngi ph c nhim

v ng m xe xch, cp ti khi bc d cht thi rn. Trng hp vi cht thi

rn nguy hi, nht thit phi b tr hai nhn lc.

+ H xe thng c nh (bc d c gii) : cng nhi vi h thng xe

thng di ng. Khi c 2 ngi th ngi li chnh cn phi gip ngi ph litrong vic cng nng cc thng rc vo thng xe, h thng v v tr.

Khi c nhiu im thu gom phn tn xe khng n tng ni c cn

phi khing thng rc t ni t n xe thu gom hoc a thng khng v ni

t th cn phi c 3 ng

i.+H xe thng c nh (bc d th cng) : Cng yu cu t 1 3 ngi

tu thuc loi cng tc thu gom v trang b dng c thu gom. Khi thu gom chtthi rn l ng, ng xm li i ch cn 1 ngi. Khi a bn rng, nhiu sn

bi sau nh cn nhiu ngi (3 ngi).

4.4. Phn tch h thng thu gom

xt nhu cu v dng c, phng tin, nhn cng i vi cc h thngthu gom ngi ta phi xc nh thi gian, n v, nh mc, thi gian hon

thnh tng nhim v cng on. Bng cch phn chia cc hot ng ngi ta cth :

- Xc nh cc s liu thit k, t chc v xc lp cc mi quan h trong h

thng.

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- nh gi cc phng n trong hot ng thu gom cht thi rn v kim

sot cc v tr c bit.

4.4.1. S ho h thng thu gom

m hnh ho h thng thu gom cht thi rn ngi ta phi phn bit

tng nhim v, tng cng on. Trn hnh 4.1, l s trnh t vn hnh hotng ca cc loi xe thng di ng. Trn hnh 4.2, l trnh t vn hnh cc loi

xe thng c nh.

T c quanbt u

hnh trnhlm vic

Cc v tr tthngCh thng yCh thng khng

V cquankt thcca lmvic

a) im tp trung

im tp trung (Bi chn lp, trm trung chuyn hoc x l)

Hnh 4.1. S trnh t vn hnh hot ng ca loi xe thng di ng

T c quann vi thng

khng, btu hnh

trnh lm vic

Xe vi thngkhng v cquan kt thcca lm vic

b)

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Xe ythng

cht thirn

Xe khng, tc quan n

imtp trung

1 2 3 4

Xe ch khng ti n hnh trnh tip theo hoc v cquan kt thc ca lm vic

Hnh 4.2. S trnh t vn hnh hot ng ca loi xe thng c nh

4.4.2. Phn tch h thng vn chuyn

Qu trnh vn chuyn bao gm bn thao tc c bn l : Bc xp chuynch cc thao tc ti im tp trung hot ng ngoi hnh trnh.

Bc xp : Thi gian bc xp cht thi rn t thng ln xe c tnhton nhsau :

- Vi h thng xe thng di ng kiu thng thng (hnh 4.1a)

Tbc xp = Tt thng khng xung + Tdi chuyn + Tbc xp ln xe (4-1)

- Vi h thng xe thng tch ri kiu thay thng (hnh 4.1b)

Tbc xp= Tbc xp ln + Tt thng khng xung (4-2)

- Vi h thng xe thng c nh

Tbc xp = N1x Tbc xp ln xe + (NP 1)Thnh trnh thu gom (4-3)

Trong :

Tt thng : Thi gian t 1 thng khng xung (pht/thng)

Tdi chuyn : Thi gian di chuyn trung bnh gia cc v tr t thng cht thi

rn (pht/im, pht/chuyn)

T bc xp ln xe : Thi gian bc xp cc thng cha y cht thi rn ln xe

(pht/chuyn)

NP: S im cn bc xp i vi 1 chuyn (im/chuyn)

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Thnh trnh thu gom : Thi gian di chuyn trung bnh gia cc v tr t thng

cha i vi h thng xe c nh.

Cn lu rng khi tnh ton phi chuyn i n v thi gian pht thnh

gi.

Chuyn ch : Thi gian chuyn ch l thi gian vn chuyn cht thi rn

t cc v tr t cc thng cha cht thi rn ti im tp trung (trm trung

chuyn, trm x l hoc bi chn lp).

Vi h thng xe thng di ng (tch ri) :

Tchuyn ch= t t im tp kt - im tp trung + tbi tp trung - im tp kt tip theo (4-4)

Vi h thng xe thng c nh :

Tchuyn ch = tt im cui ca hnh trnh - im tp trung + tim tp trung - im u ca hnh trnh mi

(4-5)

Thao tc ti bi thi: Thi gian thao tc ti bi thi c xc nh nh

sau :

Tbi= tbc d+ tch i (4-6)

Thi gian hot ng ngoi hnh trnh: Bao gm thi gian khng hiu qu

(thi gian v ch):

+ Thi gian tnh ton kim tra phng tin;

+ Thi gian i t c quan ti v tr bc xp u tin;

+ Thi gian khc phc do ngoi cnh gy ra;

+ Thi gian bo dng, sa cha thit b.

y l thi gian bt buc phi chi ph. Ngoi ra hot ng ngoi hnh

trnh cn bao gm thi gian khng bt buc :

+ Thi gian ko di khi n ung, ngh ngi v thi gian ch i, ni

chuyn.Thng thng tnh n thi gian ny ngi ta s dng h s ngoi

hnh trnh W. H s ngoi hnh trnh W c gi tr dao ng t 0,10 0,25 a s

trng hp W = 0,15.

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4.5. Xc nh cc thng s tnh ton i vi h vn chuyn hthng xe thng di ng (tch ri)

Thi gian yu cu cho mt chuyn, mt hnh trnh ca mt xe (gi tt lmt chuyn xe):

Tyu cu = (Tbc xp+ Tchuyn ch+ Tbi ) x 1/(1-W) (4-7)

Trong :

Tyu cu: Thi gian yu cu cho 1 chuyn xe (gi/chuyn)

Tbc xp: Thi gian bc xp cho 1 chuyn xe (gi/chuyn) c xc nhtheo cng thc (4-1), (4-2) v (4-3).

Thi gian bc xp v bc d thng t thay i.Tchuyn ch : Thi gian chuyn ch cho 1 chuyn

(Tchuyn ch = a+bx) (4-8)

Thi gian chuyn ch ph thuc vo chiu di qung ng v tc ca

xe. Kt qu phn tch nhiu s liu cho thy thi gian chuyn ch c th biu

th gn ng theo cng thc (4-8).

a : Hng s thc nghim (a = gi/chuyn)

a = 0,060 h/chuyn

b : Hng s thc nghim (gi/km)

b = 0,042 h/km

x : Khong cch vn chuyn cho 1 chuyn i v v (km/chuyn)

Tbi : Thi gian thao tc bi thi gi/chuyn c xc nh theo cng

thc (4-6).

T cng thc (4-7) v (4-8) ta c :

Tyu cu = (Tbc x+ Tbi+ a + bx)/(1-W) (4-9)

Trong : W : H s ngoi hnh trnh

S chuyn xe thc hin c trong mt ngy :

)( chnchuybixpbccuuyngy

TTT

W)-H(1

T

HN

++

== (4-10)

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Trong :

Nngy

: S chuyn xe thc hin c trong mt ngy (chuyn/ngy);

H : S gi lm vic trong ngy (gi/ngy)

Thi gian yu cu lm vic trong mt tun :

( )( )HW

TTTXD nchchuyibbcxpWW

++=

1

1 (4-11)

Trong :

DW: S ngy yu cu lm vic trong mt tun;

XW: S chuyn xe yu cu trong mt tun (chuyn/tun);

V.f

VX WW = (4-12)

VW: Lng cht thi rn to ra trong 1 tun (m3/tun);

V : Th tch trung bnh ca xe (m3/chuyn);

f : H s s dng dung tch xe tnh theo ti trng, thng f = 0,8.

Lu : C th tnh ton XW theo cng thc (4-12) sau lm trn s.

Xc nh nhu cu lao ng (NCL) : Nhu cu lao ng c xc nh nh

sau:S ngy cng lao ng/1 tun = DWx s ngi cn phc v

4.6. Xc nh cc thng s tnh ton i vi h vnchuyn h thng xe thng c nh

Do c s khc nhau trong khu bc xp nn ta phi xt cc trng hp

khc nhau:

a. Bc xp c gii

Thi gian yu cu cho 1 chuyn xe :

W1

1bx)aT(TT bibcxpucuy

+++= (4-13)

Trong : Tbc xp: c xc nh theo cng thc (4-3)

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Tbc xp = Ntx Tbc thng ln xe+ (NP 1) Thnh trnh thu gom

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Quản lý tổng hợp chất thải ở Campuchia, Lào và Việt Nam: Lý luận và thực tiễn Tác giả: GS. TS. Trần Hiếu Nhuệ&GS. TS. Virginia Maclaren (bt) Dự