Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 2 = HBKN
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 3 = HBKN
I ti sao phi SXSH: Chng ta bit rng, bt c mt qu trnh sn xut no cng khng th t
c hiu sut 100%. iu c ngha l / c ci g mt i vo mi trng v khng th chuyn ho thnh sn phm hu ch c. "Ci g " y l tht thot nguyn, nhin liu,... trong qu trnh sn xut.
Tht thot y gi chung l cht thi, v chnh n tr thnh trch nhim php l ca c s sn xut.
T l % lng cht thi pht sinh thng rt cao, nhng rt t ngnh cng nghip nhn ra iu .
V d 1: Tiu th nc ca ngnh Si dt Minh Khai H ni:
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 4 = HBKN
V d 2: Nh my nhit in:
Hiu sut nh my nhit in hin i ch t hiu sut 40%, trung bnh ch t khong 33%. Nh vy s dng ht 3 n v nng lng nhit th ch c 1 n v nng lng bin thnh in nng, cn 2 n v nhit s tr thnh ngun nhim cho MT xung quanh.
V d 3: Sn xut gch nung:
Qu trnh sn xut c th hin theo s sau:
V d 4: Sn xut giy:
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 5 = HBKN
Vy: y ny sinh ra 2 vn :
- i vi doanh nghip: b tht thot nguyn liu u vo, phi tr tin chi ph x l cht thi nh hng n vn kinh t.
- i vi x hi: phi tip nhn cht nhim nh hng n cht lng mi trng sng.
Trong thc t sn xut, vic ti u ho chi ph cho qu trnh sn xut ch tp trung vo nng sut v thng b qua kh nng pht sinh cht thi. Bi v mc tiu hng ti ca cc nh sn xut l lm th no to ra nng sut cao mc d c th tiu th nhiu nguyn liu th v nhin liu; iu dn ti gia tng cht thi v nh hng n mi trng.
Chnh ph c nhim v bo v mi trng cho ngi dn gy sc p i vi doanh nghip cn hn ch ti a cht thi nhim ra mi trng.
m bo cht lng mi trng, tu theo giai on pht trin m / din ra nhng cch thc thc hin khc nhau:
Trc nm 50, cht thi ra con ngi trng ch vo kh nng t lm sch ca thin nhin.
Nhng nm 60, / c mt s bin php gim thiu tc hi ca cht nhim i vi sc kho con ngi:
- Nng chiu cao ng khi. - Pha lo/ng nc thi. - a cht thi ra ngoi phm vi sinh sng ca con ngi.
Nhng nm 70: tip cn vi cc gii php x l cht thi, nh: xy dng cc nh nh my x l nc thi, thit b lc bi, kh c, chn lp cht thi an ton,...
Vi cch gii quyt ny ch c thc hin sau khi cht thi / sinh ra v c gi l gii php cui ng ng (EOP: End Of Pipe) cho cht thi i qua h thng x l trc khi thi ra mi trng.
Cch tip cn ny khng trit v thc cht qua h thng x l cht thi chuyn t dng nhim ny sang dng nhim khc. Ngoi ra, cch tip cn ny cn chi ph kh ln, song li khng sinh li, khng hy vng thu hi c c hai kha cnh kinh t v MT, nn cc doanh nghip khng mun thc hin.
T nhng nm 80 n nay: tip cn phng nga nhim, gim thiu cht thi ra i tip cn mang tnh ch ng.
Cc thut ng th hin tip cn ny:
- Sn xut sch hn (1985). - Phng nga nhim. - Gim thiu cht thi.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 6 = HBKN
- Nng sut xanh. - Hiu sut sinh thi.
Nh vy, trc y coi qu trnh cng ngh l mt hp en v ch n cht thi sau khi / to ra; gii quyt vn cht thi, cc doanh nghip ch c gii php quen thuc l x l cui ng ng.
Di sc p ca x/ hi v chnh ph lc ny cc ngnh cng nghip mi nhn ra s cn thit phi xem xt li dy chuyn sn xut (tc hp en) v t xut hin gii php ch ng ngn nga gim thiu cht thi ngay ti ni pht sinh trong qu trnh sn xut. chnh l l do ti sao phi SXSH.
II - Sn xut sch hn l g? Mc tiu ca SXSH l trnh nhim bng cch s dng ti nguyn,
nguyn vt liu v nng lng mt cch c hiu qu nht. iu ny c ngha l thay v b thi b s c thm mt t l nguyn vt liu na c chuyn vo thnh phm. t c iu ny cn phi phn tch mt cch chi tit v h thng trnh t vn hnh cng nh thit b sn xut hay yu cu mt nh gi v SXSH.
Tm li: mc tiu ca SXSH l:
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 7 = HBKN
1 1 1 1 ---- Cc khi nim v SXSH: Cc khi nim v SXSH: Cc khi nim v SXSH: Cc khi nim v SXSH: To ra cc sn phm khng gy c hi i vi MT.
Hp l v mt sinh thi, a cht lng cuc sng ph hp vi kh nng ti c ca Tri t qua vic gim tc ng ti MT sinh thi v s qu ti v s dng ti nguyn trong sut vng i ca sn phm.
Mc thi hoc pht thi bng 0, ngha l s dng cc nguyn liu, cc qu trnh sao cho lm gim hoc loi tr pht sinh cht thi.
S dng cng ngh hoc thit b t to ra cht thi hn cc cng ngh hoc thit b truyn thng.
Theo ti liu "T cht thi ti nhng li nhun" ca Hi ng Quc gia v nng sut - n , th:
Sn xut sch l mt cch ngh mi v c tnh sng to trong t duy v sn phm v qu trnh sn xut to ra sn phm. SXSH t c thng qua vic p dng lin tc nhng chin lc nhm gim thiu pht sinh ra cht thi v pht thi.
Theo nh ngha ca Chng trnh Mi trng Lin hip quc (UNEP):
Sn xut sch hn l vic p dng lin tc mt chin lc tng hp phng nga v mi trng i vi qu trnh sn xut, sn phm v dch v nhm nng cao hiu sut kinh t v gim ri ro cho con ngi v mi trng.
Tm tt nh ngha SXSH:
2 2 2 2 ---- SXSH i vi cc qu trnh: SXSH i vi cc qu trnh: SXSH i vi cc qu trnh: SXSH i vi cc qu trnh: - i vi qu trnh sn xut:
Gim tiu th nguyn liu v nng lng cho mt n v sn phm.
Loi b ti a cc vt liu c hi.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 8 = HBKN
Gim lng v c tnh ca tt c cc dng thi trc khi chng ra khi qu trnh sn xut.
- i vi sn phm: SXSH l gim tc ng tiu cc trong chu trnh sng (vng i) ca sn phm, tnh t khi khai thc nguyn liu n khi thi b cui cng.
- i vi dch v: SXSH l gim cc tc ng ti mi trng ca dch v cung cp trong sut vng i ca sn phm t thit k v s dng h thng dch v n tiu th ton b ngun hng dch v.
3 3 3 3 ---- yu cu ch yu ca SXSH: yu cu ch yu ca SXSH: yu cu ch yu ca SXSH: yu cu ch yu ca SXSH:
p dng kin thc cng ngh (tip cn c h thng b quyt cng ngh).
Thay i thi , cch nhn.
Ci tin tng bc cng ngh hin c.
Thay i hng ti cc cng ngh mi tt v sch hn.
4 4 4 4 ---- Li ch ca SXSH: Li ch ca SXSH: Li ch ca SXSH: Li ch ca SXSH:
Hai li ch chnh:
- Gim cht thi ng ngha vi gim nhim mi trng c li v mt mi trng.
- Gim cht thi ng ngha vi gim nguyn liu th u vo hoc tng sn phm u ra c li v mt kinh t.
Cc v d minh ho li ch sxsh:Cc v d minh ho li ch sxsh:Cc v d minh ho li ch sxsh:Cc v d minh ho li ch sxsh:
V d 1: Mt cng ty dt / gim c lng thuc nhum, nc, nng lng s dng v lng nc thi thng qua vic ti s dng b nhum cui ca mt vng tun hon chun b cho vng tip theo. Chi ph u t l $15.000, tit kim hng nm l $100.000, thi hn hon vn ch c 2 thng.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 9 = HBKN
V d 2: Trong nh my bia, mt t hp gm 8 qu trnh c thay i / lm gim tng lng COD v gim khong 19% lng cht thi rn. Tit kim ch tnh ring i vi dng thi / l $96.000 mi nm.
V d 3: Nh my giy Vnh Kh l mt trong nhng c s sn xut giy ca Vit nam tham gia trnh din p dng SXSH. Trc khi p dng SXSH b phn l hi cn 390 - 400 lt du FO/tn giy v lng nc thi cn x l l 4.800 m3/ngy. Hin nay sau khi p dng SXSH lng nc thi ch cn 2.500 m3/ngy.
V d 4: Nh my giy Vit Tr u t 200 triu thc hin SXSH, sau 2 nm / thu li li nhun hn 2 t ng.
a/ Nhng li ch trc tip khi p dng SXSH:
V kinh t, nh nng cao hiu qu bo ton c nguyn liu th v nng lng, gim chi ph x l cui ng ng, ci thin c mi trng bn trong v bn ngoi cng ty. C th l:
- Nng cao hiu qu do p dng SXSH dn n hiu qu sn xut tt hn, ngha l c nhiu sn phm c sn xut ra hn trn mt n v u vo ca nguyn liu th.
- Bo ton nguyn liu th v nng lng: do gim tiu th nguyn liu th v nng lng nn gim c chi ph u vo; ng thi cng gim c chi ph x l. y l yu t cc doanh nghip c bit quan tm v ngun ti nguyn ngy cng cn kit, gi c th tng cao.
- Ci thin mi trng bn ngoi: thc hin SXSH s gim c lng v mc c hi ca cht thi nn m bo cht lng mi trng, ng thi gim nhu cu lp t vn hnh thit b x l cui ng ng.
- Ci thin mi trng bn trong (mi trng lm vic): iu kin mi trng lm vic ca ngi lao ng c ci thin do cng ngh sn xut t r r cht thi hn; qun l ni vi tt nn mi trng lm vic sch s v trong lnh hn, t pht sinh ra tai nn lao ng, gim ng k cc bnh ngh nghip,...
- Thu hi nhiu ph liu v ph phm.
- Tun th cc qui nh lut php tt hn.
- Cc c hi th trng mi & hp dn.
b/ Nhng li th v li ch gin tip khi p dng SXSH:
- Tip cn d dng vi cc ngun ti chnh: do SXSH to ra hnh nh mi trng c tnh tch cc cho ng ty i vi pha cho vay vn, do s tip cn tt hn vi ngun ti chnh.
- Tun th tt hn cc qui nh v mi trng: do SXSH gip x l cc dng thi d dng, n gin v r hn nn tun th c cc tiu chun x thi.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 10 = HBKN
- Cc c hi th trng mi v tt hn: do nhn thc ca ngi tiu dng v mi trng ngy cng tng nn i hi cc doanh nghip phi th hin c s thn thin vi mi trng trong cc sn phm v qu trnh sn xut ca h. Cc doanh nghip thc hin SXSH s p ng cc tiu chun v mi trng nh ISO14000, hoc yu cu ca th trng nh nh/n sinh thi.
- Hnh nh tt hn vi cng ng: SXSH to ra hnh nh xanh cho doanh nghip, s c x/ hi v cc c quan hu quan chp nhn. Trnh cc bo co truyn thng bt li c th hu hoi danh ting / to dng trong nhiu nm ca cng ty.
p dng chin lc SXSH s gip cng ty c c sc mnh cnh tranh trn th trng:
S khc nhau gia 2 cch tip cn:
5 5 5 5 ---- TTTTr ngi i vi SXSH:r ngi i vi SXSH:r ngi i vi SXSH:r ngi i vi SXSH: C s phn i nhng sng kin v tip cn mi do nhn vin khng c o to chnh qui. Cc d n trnh din l rt cn thit chng minh rng SXSH c th p dng c trong cng ty mnh.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 11 = HBKN
Thiu ngun ti chnh, nhn thc o to, chuyn mn v cng ngh, thng tin v tip cn vi nhng kin thc hin c.
C s bt trc v tnh ng n ca thng tin, cng ngh hay cc qui nh.
Cc chnh sch ca Chnh ph tp trung vo gim cht nhim / khng khuyn khch cho cc gii php gim nhim v to ra s khch l v thu i vi vic u t cho cc cng ngh x l cui ng ng.
a/ Tr ngi v kinh t:
Nhng khon u t cho SXSH khng l/i bng mt s c hi u t khc.
Non nt trong hot ng tnh ton chi ph ni ti v phn b chi ph ca cng ty.
Yu km trong vic lp k hoch chi tiu vn ni ti v th tc phn b vn ca cng ty.
b/ Tr ngi v chnh sch: (pha nh nc)
Cha ch trng y n SXSH trong pht trin chin lc mi trng, cng ngh, thng mi v cng nghip.
Thiu chn chn trong khung chnh sch mi trng (bao gm c vic thiu tnh cng ch,...)
c/ Tr ngi v t chc:
Thiu vai tr l/nh o i vi cc vn v mi trng.
Khng c s khuyn khch cho cc nh qun l h n lc trong vic thc hin SXSH.
S non nt ca chc nng qun l mi trng trong hot ng ca cng ty.
Thiu ht trong c cu t chc v h thng qun l v thng tin ca cng ty.
Thiu s tham gia ca cc nhn vin trc tip sn xut trong hot ng SXSH.
d/ Tr ngi v k thut:
Thiu c s vn hnh hiu qu cc k hoch / c thit lp.
Phc tp ca qu trnh SXSH. V d: cn phi thc hin nh gi tng th xc nh c hi SXSH ph hp).
Kh nng s dng hn ch i vi cc thit b h tr cho SXSH. V d: s dng cc thit b o c c cht lng cao cho qu trnh qui m nh,...
Kh nng tip cn hn ch i vi nhng thng tin k thut ng tin cy vi nhu cu v kh nng ng dng ca cng ty.
e/ Tr ngi v nhn thc:
Thiu quan tm nhm nng cao nhn thc lin quan n vai tr c nhn trong ng gp ci thin mi trng.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 12 = HBKN
Hiu cha r khi nim SXSH.
Tnh bo th.
6 6 6 6 ---- Phn bit SXSH: Phn bit SXSH: Phn bit SXSH: Phn bit SXSH: Nhng g khng phi l SXSH?
- S dng cc h thng kim sot nhim cui ng ng truyn thng x l cht thi theo cc quy nh v gii hn cho php.
- Cc bin php k thut x l cht thi.
Nhng g ph hp vi khi nim SXSH?
- Vn hnh hiu qu mt trm x l bn ngoi quy trnh cng ngh.
Nhng g cng c th l SXSH?
- Ti sinh bn ngoi v nguyn tc khng phi l mt b phn cu thnh nn SXSH v chng khng tp trung vo nguyn tc ch ng phng nga. Tuy nhin nguyn tc c th p dng cho SXSH.
7 7 7 7 ---- p dng sxsh vo cng nghip: p dng sxsh vo cng nghip: p dng sxsh vo cng nghip: p dng sxsh vo cng nghip: Cp qun l cn phi cam kt v nhit tnh i vi SXSH.
Cn phi theo ui mt tip cn tng hp v mang tnh h thng.
Cn c s tham gia ca cng nhn v ngi lao ng tt c cc cp t chc ca c s th mi t c kt qu tt.
Ch khuyn khch thng pht.
Cn phi t chc o to ni b cho cng nhn, nhn vin gim st v cp qun l xc nh c cc c hi v thc hin SXSH.
III - pht trin bn vng & SXSH Pht trin bn vng (PTBV) l s pht trin nhm p ng nhng nhu cu
ca cuc sng hin ti m khng lm tn hi n nhng nhu cu cho th h mai sau.
V mt mi trng:
- Gii hn v mi trng i vi s pht trin ca con ngi l kh nng cung cp ti nguyn v cha ng rc thi ca mi trng l c hn.
- Cht lng mi trng nh hng trc tip n sc kho ca con ngi v thin nhin.
V mt kinh t:
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 13 = HBKN
- S tng trng l iu kin tt yu p ng nhu cu cuc sng ca con ngi.
V mt x/ hi :
- S pht trin bao gm nng cao i sng vt cht v tinh thn.
Quan h gia SXSH vi PTBV: SXSH l cng c thc hin pht trin bn vng.
IV - h thng qun l mi trng EMS / ISO14000 & SXSH ISO: International Standard Organization.
ISO14000 l tp hp cc tiu chun qun l mi trng quc t.
EMS : Enviromental Management System.
Tiu chun ISO14000 ch mang tnh cht khuyn khch, t nguyn p dng ch khng phi l bt buc, th hin trch nhim ca cng ty i vi vn mi trng.
H thng ny cung cp mt tip cn c t chc trong vic lp k hoch v thc hin cc bin php bo v mi trng. pht trin mt h thng qun l mi trng, cn phi nh gi c cc tc ng mi trng, xc nh c cc mc tiu gim cc tc ng tiu cc v lp k hoch t c nhng mc tiu ny. Cc li ch ca h thng qun l mi trng:
Gim thiu cc ri ro hay trch nhim v mi trng; S dng c hiu qu ti a cc ti nguyn; Gim cc cht thi; To ra hnh nh hp tc tt; Xy dng cac mi quan tm v mi trng cho nhn vin;
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 14 = HBKN
Hiu r cc tc ng mi trng ca hot ng kinh doanh; Tng li nhun v ci thin hin trng mi trng thng qua hot ng c
hiu qu hn.
1 1 1 1 ---- Cu trc ISO 14000: Cu trc ISO 14000: Cu trc ISO 14000: Cu trc ISO 14000: Bt u c tin hnh xy dng vo thng 6/1993, c tin hnh
Toronto (Canada).
ISO 14001-14009: Cc tiu chun v h thng qun l mi trng (EMS - Enviromental Management System).
ISO 14010-14019: Cc tiu chun v kim tra mi trng (EA - Enviromental Auditing).
ISO 14020-14029: Cc tiu chun v nh/n mi trng (EL - Enviromental Labeling).
ISO 14030-14039: Cc tiu chun v nh gi thc thi mi trng (EPE - Enviromental Performance Evaluation).
ISO 14040-14049: Cc tiu chun v nh gi chu trnh sng (LCA - Life Cycle Assessment).
ISO 14050-14059: Cc tiu chun v phm tr, nh ngha.
2 2 2 2 ---- chu trnh ci thin lin tc ISO14000: chu trnh ci thin lin tc ISO14000: chu trnh ci thin lin tc ISO14000: chu trnh ci thin lin tc ISO14000:
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 15 = HBKN
a/ Chnh sch mi trng:
b/ Lp k hoch:
Kha cnh mi trng:
Xc nh cc kha cnh mi trng m cng ty c th kim sot.
Xc nh kha cnh c th gy ra tc ng n mi trng .
Cn nhc cc kha cnh quan trng khi thit lp.
Duy tr cp nht cc thng tin.
Thit lp mt th tc thc hin.
Yu cu v lut php &Yu cu khc :
Danh mc cc yu cu c th p dng (gii hn kh thi, nc thi,...).
Thng bo cho l/nh o v nhn vin v yu cu php lut c lin quan.
Lp k hoch tun th php lut.
Mc tiu & ch tiu :
Mc tiu v ch tiu phi da trn:
Yu cu v lut php v cc yu cu khc.
Cc kha cnh mi trng quan trng.
Cc phng n cng ngh, cc yu cu v ti chnh, vn hnh v kinh doanh.
Cn nhc ti kin ca cc bn lin quan.
Chng trnh qun l mi trng:
Chng trnh qun l mi trng nhm t c cc mc tiu v ch tiu, gm:
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 16 = HBKN
- nh r trch nhim cho cc b phn chc nng, cc cp.
- Bin php v khung thi gian.
Phng thc lng ghp cc d n mi hoc thay i trong kinh doanh.
Bng chng v vic tun th.
3 3 3 3 ---- quan h gia ISO 14000 vi sxsh: quan h gia ISO 14000 vi sxsh: quan h gia ISO 14000 vi sxsh: quan h gia ISO 14000 vi sxsh: SXSH l cng c h tr thc hin tt h thng qun l mi trng.
Thc hin tt SXSH s c c hi nhn c chng ch ISO14000.
ISO14000 h tr cung cp c s d liu thc hin SXSH.
Cng nh sn xut sch hn v hiu sut sinh thi, mt h thng qun l mi trng c th l mt cng c c lc cho mt t chc ci thin hin trng mi trng, ng thi nng cao hiu qu kinh doanh. Vic thc hin mt h thng qun l mi trng to ra nhng c hi l tng thc hin sn xut sch hn, tng t sn xut sch hn s l cng c t chc c th ci thin hin trng kinh t v mi trng ca mnh. Nh vy sn xut sch hn l mt trong nhng ni dung c quan tm nht trong phn mc ch cn t c ca h thng qun l mi trng.
V - chu trnh sng - nh gi vng i sn phm (LCA) & SXSH
LCA: Life Cycle Assessment.
1 1 1 1 ---- khi nim & nh ngha: khi nim & nh ngha: khi nim & nh ngha: khi nim & nh ngha: Khi nim: LCA l mt thut ng ch mt cng c c tnh phng
php lun nhm gn cht nhng nguyn tc ca mi trng vi hot ng ca doanh nghip.
c im: LCA tnh ton cc dng vt cht v nng lng u vo v u ra ca mt h thng da trn nguyn tc xem xt ton b chu trnh sng ca n v nh gi theo tiu ch mi trng.
y l mt phng php mang tnh nh lng nh gi nhng tc ng ca con ngi i vi mi trng, nhm cung cp thng tin v cc tc ng mi trng ca cc sn phm v cc qu trnh sn xut.
Theo nh ngha UNEP: LCA l cng c nh gi tc ng cho mt sn phm gy ra i vi mi trng trong sut vng i ca n t khai thc ch bin nguyn liu sn xut ng gi tiu th th trng s dng ti s dng bo dng thi b cui cng.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 17 = HBKN
Theo SFTAC (cc ha cht v bo v mi trng): LCA l phng php khch quan nh gi cc gnh nng mi trng lin quan n sn phm. Quy trnh hay hot ng bng cch nhn dng hay nh lng cc loi nng lng, nguyn vt liu s dng v cc loi tc hi. Sau tin hnh nh gi tc ng ca chng v a ra cc c hi nhm ci thin mi trng.
Theo EPA (M): LCA l cng c nh gi cc h qu ca mi trng ca mt sn phm v cc hot ng xuyn sut ton b vng i ca n.
2 2 2 2 ---- phngphngphngphng ph ph ph php lun ca lca:p lun ca lca:p lun ca lca:p lun ca lca: Xc nh phm vi v mc tiu
Phn tch kim k
Phn tch cc tc ng mi trng
a/ Xc nh phm vi & mc tiu :
Cc mc tiu c th l:
Ti u ho qu trnh .
Ti u ho sn phm.
Xy dng mng li thng tin ni b.
Xy dng mng li thng tin cho cc bn lin quan (khch hng, nh cung ng).
Cn phi lm r ranh gii chc nng ca h thng. Xc nh ranh gii h thng nhm xc nh mt h thng gm nhiu cng on lin h vi nhau thc hin mt chc nng nht nh.
La chn, xut cc gii php thch hp
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 18 = HBKN
b/ Phn tch & kim k :
LCA cn mt khi lng d liu khng l t nhiu kha cnh, cc d liu cn phi c s thng nht n v o, phng php o v tnh ton.
c/ nh gi tc ng
Da vo d liu thu thp c trn xem xt phn tch cc tc ng ca n i vi mi trng, ti nguyn v h sinh thi.
Nhng tc ng xy ra c th l:
Nguy c nng ln ca Tri t.
Hiu ng nh knh.
Suy gim tng zn.
Ma axit.
Khi quang ho.
Giao trnh SAN XUT SACH HN
Nguyn nh Hun = 19 = HBKN
nhim t, nc, khng kh.
Cn kit ngun ti nguyn thin nhin.
Mt cn bng h sinh thi.