do an mia duong

7/28/2019 do an mia duong

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GVHD: Hunh Th Ngc Hn 1

CHNG I: TNG QUAN V NGNH CNG NGHIP MANG

1.1. Tng quan quy trnh cng ngh sn xut

Nguyn liu sn xut: ma

Ma c trng cc vng nhit i (nc ta )v cn nhit i. Vic thuhoch ma phi ng thi v mi c th thu c sn lng cng nh cht lngng cao nht. Cng nghip ch bin ng hot ng theo ma vdo lngcht thi cng ph thuc v ma thu hoch . Quy trnh sn xut ng gm 2 giaion: sn xut ng th v sn xut ng tinh.

1.1.1. Thnh phn ca ma v nc ma

Thnh phn ca ma ph thuc v tng vng trng ,nhng n dao ngtrong cc khong sau:

Nc 69-75%

Sacroso 8-16%

ng kh 0,5-2%Cht hu c

(ngoi trng) 0,5-10%

Cht v c 0,2-0,6%

Hp cht nito 0,5-1%

Tro ( Phn ln l K)

0,3-0,8%


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Ncma c tnh axit (pH=4,9-7,5), c(do s hin din ca cc cht keonh sp ,protein, nha, tinh bt v silic) v c mu xanh lc. Thnh phn nc manh sau:

Mu ca nc ma l do:

+T thn cy ma: mu do chlorophyl, anthocyanin, saccharetin v tanin

gy ra.

Chlorophyll thng c trong nc ma, n lm cho nc ma c muxanh lc. Trong nc ma, chlorophyll trng thi keo, n d dng bloi b bng phng php lc.

Anthocyanin ch c trong loi ma c mu sm, n dng ha tan trongnc. Khi thm nc vi, mu ta ca anthocyanin b chuyn sangmu xanh lc thm. Mu ny kh b loi b bng kt ta vi vi (vlng vi dng trong cng ngh sn xut ma ng khng ln) hayvi H2SO4.

Saccharetin thng c trong v cy ma. Khi thm vi, cht ny s tr

thnh mu vng c trch ly. Tuy nhin loi mu ny khng gy c,

mi trng Ph


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+ Do cc phn ng phn hy ha hc

Khi cho vo nc ma lng nc vi, hoc di tc dng nhit nc mab i mu.

+ Do s phn ng ca cc cht khng ng vi nhng cht khc.

loi b cc tp cht trong nc ma c th p dng cc bin php sau:

c: c loi bng phng php lc.

Nha v pectin, mui ca cc axit hu c, v c, cht to mu: c loib bng phng php x l vi vi.

1.1.2. Ha cht lm trong v ty mu

Vi CaCO3:

- C tc dng trung ha cc axit hu c c trong nc ma.

- Phn ng vi axit photphoric to Ca3(PO4)2

- Kt hp vi hp cht nito v pectin to kt ta.

- Lm kt ta cc hp cht to mu gc chlorophyll v anthocyanin.

- Tc dng vi sucrose to saccharate, glucosates

Kh SO2

- Trung ha lng vi tha:- Ca(OH)2+H2 SO3= CaSO3+H2O- Ty mu nc ma- Kh CO2- Hp ph cht to mu

H3PO4

- Kt hp vi vi lm trong nc ma

Ha cht ty mu: penton- kt hp gia nc oxy gi vi st

sunphat

- Dng Na2S2O4


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1.1.3. Quy trnh sn xut ng th

Nc r cy ma nc thi

Nc ngm ma B ma, bt

vi H3PO4

Nc Hi nc ngng t

CO2

B ma( l hi) Hi nc , kh thi

Nc hi nc

Nc hi nc , rng

ng th

Nc ma c tnh axit( pH=4,9-7,5), c, c mu xanh lc(cha 13-15% cht tan,trong cht kh cha 82-85% ng saccarose).Nc ma c x l bng cc chtha hc nh vi, CO2, SO2, PO4

3- ri c un nng lm trong. Qa trnh x lny c chc nng lm kt ta cc cht rn, huyn ph v lng c cht bn. Dung dchtrong c lc qua my lc chn khng. B lc c loi b, em thi hoc dnglm phn bn. Nc ma sau khi lc cn cha khong 88% nc, sau c bc

Cy ma

p ma

Gia nhit ln 1

Xng co2

Sunfit ha ln 1

C c

Sunfit ha ln 2

Gia nhit ln 2

Kt tinh, phn ly


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hi trong l nu chn khng. Hn hp tinh th v mt c thu vo my ly tm tch ng ra khi mt r. Rng l dung dch c nht cao, cha khong 1/3ng kh.

Cc cht thi t qu trnh sn xut c thc ti ch lm cc sn phm thnthin vi mi trng nh:

i vi b ma c th lm : Bt giy, tm x p, nha, b tng.

i vi mt ma: phn bn, thc n gia sc, alcohol,dm, axeton

Ni chung, lng nc thi trong cng nghip sn xut ng th rt ln baogm : nc ra ma cy , kh c thot ra tl hi, nc xy l hi, nc lm mtthit b, nc ra sn, ha cht v cc cht khc ri vi trong qu trnh sn xut.

1.1.4. Cng ngh sn xut ng tinh

ng th

vi H3PO4

than hot tnh bt trlc

sir tinh lc

tch nc

Thuyt minh quy trnh sn xu:

a.Ra v ha tan

- Ra: Lm sch lp ngoi cng ca ng th trn nng cao trngca ng.

- Ha tan: ng sau khi dng my ly tm trn u c ha tan vonc thnh dung dch nc ng nguyn cht n khu ha ch.

Ra v ha

Lm trong

Lm sch

Kt tinh Tinh thng+mt


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b. Lm trong:Nc ng nguyn cht c x l bng cc chtha hc nh vi H3PO4 lm tron. Qa trnh ny c chc nnglm kt ta cc chat rn huyn ph v lm lng cc cht bn.

c.Lm sch : Nc ng sau khi lng trong c cho thm than

hot tnh v bt tr lc kh mu v tng cng khnng lmtrong. Nc ng sau lc gi l sir tinh lc.d.Kt tinh: nhim v ca vic nu ng l tch nc t sir tinhlc v a dung dch n trng thi bo ha .Sn phm cui cng lng tinh v mt ci.

1.2. Hin trng ngnh sn xut ng ca Vit NamNgnh sn xut ma ng Vit Nam ni chung l cha thc s pht trin , so

vi th gii th cn rt lc hu. V mt k thut cng ngh, cn th s, cha thc sci tin. i vi t , tuy mu mnhng chng ta cha tn dng c ht nn nngsut ma thu c cn thp ( do trnh k thut canh tc cn thp).Kt qu l snlng ng thu c t ma cn rt thp.

T mt k thut cng thy c ngnh cn nhiu vn bt cp, c bitl vn mi trng. ngnh ma ng thi ra rt nhiu cht c kh xl nh: bikhi l hi, bn lc , nc thi c hm lng COD, BOD cao, kh thot ra t ccthp phn ng sunfit ha,v cacbonat ha.Bn cnh th mt s cht thi c th tich thnh cc sn phm than thin vi mi trng :

B ma: lm nhin liu, giy, nha, b tng Mt: phn bn, thc n gia sc, alcohol,dm, axeton

1.3. Nc thi ngnh sn xut ma ng

Da vo quy trnh sn xut ng, chng ta c thchia nc thi ca ngnhthnh cc nhm sau:1.3.1. Nc thi t khu p ma

i vi b ma(chim 25-30% trng lng ma em p)

Thnh phn T l

Nc 49%

X 48% (45-55% xellulose)

ng kh 2,5%


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i vi mt r(chim 3-5% trng lng ma em p)

i vi bn lc(1,5-3%)Ni chung nc thi t khu p ma c nng BOD cao, c cha nhiu

cht dinh dng.

1.3.2. Nc thi ra lc,lm mt,ra thit b v sa snNc thi ra lc tuy c lulng nhnhng gi tr BOD v cc cht l

lng cao.

Nc lm mt c dng vi lng ln v thng c tun hon hu hthoc mt phn trong quy trnh sn xut. Nc lm mt thng nhim bn mt scht hu c bay hi tnc ng un si trong ni nu hoc ni chn khng. Ncchy trn tcc thp lm mt thng c gi tr BOD thp. Tuy nhin, do ch bodng my mc km v iu kin vn hnh khng tt nn c lng ng ng k

tht thot trong nc lm mt. Lng nc ny sc thi i.Nc r rv nc ra trn, ra thit btuy c lu lng thp v c x

nh knhng c hm lng BOD v SS rt cao.

Thnh phn T l

Nc 20%

saccarose 35%

ng kh 20%

Protein 5%

Tro 15%

Sp 1%

Bt 4%


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1.3.3.Nc thi khu l hi

Nc thi khu l hi c xnh k, vi c im l cht rn l lng caov gi tr BOD thp, nc thi mang tnh kim.

Bng 1: Sliu thnh phn nc thi ma ng(QCVN 2008)

STT Ch tiu n v Gi tr QC

1 pH mg/l 7,5-8 5,5-9

2 SS mg/l 1250 100

3 BOD5 mg/l 5000 50

4 COD mg/l 7000 100

5 Nt mg/l 16,4 30

6 Pt mg/l 7,5 6

1.4. Khnng gy nhim ngun nc ca nc thi ngnh ma ng

Hin nay, a scc nh my ng v nhiu hnh thc sn xut t nhn chac h thng xl nc thi t tiu chun. Vi lu lng ln, hm lng cht hu

c v cht dinh dng cao nc thi ma ng v ang lm gy nhim cao chocc ngun tip nhn.

ng c trong nc thi ch yu l ng sacroza v cc loi ngkhnh glucose v fructose.

Cc loi ng ny d phn hy trong nc. Chng c khnng gy kit oxytrong nc, lm nh hng n cc hot ng ca qun th vi sinh vt trong nc.


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CHNG II: CC PHNG PHP XL NC THI

2.1. Cc phng php xl

Vic x l nc thi nhm gim nng cc cht nhim trong nc thi n

mt nng theo quy chun k thut Vit Nam nm 2008 v quy nh mc x

thi. Vic la chn phng php lm sch v la chn quy trnh x l nc ph

thuc vo cc yu t nh :

Cc yu cu v cng ngh v v sinh nc.

Lu lng nc thi.

Quy trnh sn xut ma ng. Vt liu u vo.

Hiu qu x l.

2.1.1. Phng php x l c hc

Mc ch l tch cht rn, cn, phn ra khi hn hp nc thi bng cch thu

gom, phn ring. C th dng song chn rc loi b cn th, d lng to iu kin

thun li v gim khi tch ca cc cng trnh x l tip theo. Do phi lng s btrc ri a sang cng trnh x l tip theo.

Sau khi tch, nc thi c a sang cc cng trnh pha sau, cn phn cht

rn c em i lm phn bn.

Song chn rc:

tch b ma trong nc thi ngi ta dng song chn rc. Hiu sut

ca qu trnh tch cht rn bng phng php ny ph thuc vo cc yu tsau:

c tnh c hc ca song, li: kch thc mt sn, khong cchgia cc thanh chn, lu lng dng chy v iu kin dng chy.

Tnh cht nc thi :nng cht rn, kch thc ca cht thi cntch,


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u im:

n gin, r tin, d lp t. Gi li tt c cc tp vt ln.

Nhc im:

Khng x l, ch gi li tm thi cc tp vt ln. Lm tng tr lc h thng theo thi gian. Phi x l rc th cp

Khi nc thi qua song chn rc c th gim c 4%SS v BOD.

B lng ct

B lng ct dng tch cc cht bn v c c trng lng ring ln hn nhiu

so vi trng lng ring ca nc nh xthan, ct ra khi nc th. Ct t b

lng ct c a i phi kh sn phi v ct kh thng c s dng li chonhng mc ch xy dng.

Nc thi qua b lng ct c th gim c 5%SS, BOD.

Biu ha

t sau b lng ct v trc b lng 1.

Do lu lng, thnh phn, tnh cht nc thi khng n nh, thay i

theo ngy m . n nh ch dng chy cng nh cht lng ncu vo cho cc cng trnh x l pha sau, cn thit phi c mt b iu halu lng v nng . Dung tch b c chn theo thi gian iu ha, davo biu thay i lu lng, nng nc thi v yu cu mc iuha nng nc thi.

Trong b phi c h thng thit b khuy trn m bo ha tan vsan u nng cc cht bn trong ton th tch( loi tr cc c sc vcht lng cho cc cng trnh x l sinh hc pha sau v khng cho cnlng trongb.

Nc thi qua biu ha c th gim c 5%SS v 35%BOD.

B lng

B lng dng tch cc cht l lng c trng lng ring ln hn

trng lng ring ca nc. Cht l lng nng hn s t t lng xung y,

cn cht l lng nhhn s ni ln mt nc hoc tip tc theo dng nc


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n cng trnh x l tip theo. Dng nhng thit b thu gom v vn chuyn

cc cht bn lng v ni (ta gi l cn ) ti cng trnh x l cn .

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

t 1 trc cng trnh x l sinh hc v b lng t 2 sau cng trnh x l sinh hc.

Da vo nguyn tc hot ng, ngi ta c th chia ra cc loi b lng

nh: b lng hot ng gin on hoc b lng hot ng lin tc.

Da vo cu to c th chia b lng thnh cc loi nh sau: b lng

ng, b lng ngang, b lng ly tm v mt s b lng khc.

o B lng ng

B lng ng c dng hnh trn hoc hnh ch nht trn mt bng. Blng ng thng dng cho cc trm x l c cng sut di

15.000 m3/24h. Nc thi c dn vo ng trung tm v chuyn ng t

di ln theo phng thng ng. Vn tc dng nc chuyn ng ln phi

nhhn vn tc ca cc ht lng. Nc trong c tp trung vo mng thu

pha trn. Cn lng c cha phn hnh nn hoc chp ct pha di.

Nc thi qua b lng ng c th gim c 40%SS v 20-40%BOD

oB lng ngang

B lng ngang c hnh dng ch nht trn mt bng, t l gia chiu

rng v chiu di khng nhhn v chiu su n 4m. B lng ngang

dng cho cc trm x l c cng sut ln hn 15.000 m3/ 24h. Trong b

lng nc thi chuyn ng theo phng ngang tu bn cui b v

c dn ti cc cng trnh x l tip theo, vn tc dng chy trong vngcng tc ca bkhng c vt qu 40 mm/s. B lng ngang c h thu

cn u bv nc trong c thu vo mng cui b.

Nc thi qua b lng ngang c th gim c 60%SS v 20-40%

BOD.


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o B lng li tm

B lng ly tm c dng hnh trn trn mt bng. B lng ly tm c

dng cho cc trm x l c cng sut ln hn 20.000 m3/ngym. Trong

b lng nc chy t trung tm ra quanh thnh b. Cn lng c dn vo

h thu cn c xy dng trung tm y b bng h thng co gom cn

phn di dn quay hp vi trc 1 gc 450. y b thng c thit k

vi dc i = 0,020,05. Dn quay vi tc 2-3 vng trong 1 gi. Nc

trong c thu vo mng t dc theo thnh b pha trn.

B vt du m

B vt du mthng c p dng khi xl nc thi c cha du

m(nc thi cng nghip), nhm tch cc tp cht nh. i vi thi sinh

hot khi hm lng du mkhng cao th vic vt du mthc hin ngay

b lng nhthit b gt cht ni.

B lc

B lc nhm tch cc cht trng thi l lng kch thc nh bng

cch cho nc thi i qua lp lc c bit hoc qua lp vt liu lc. B ny

c s dng ch yu cho mt s loi nc thi cng nghip. Qu trnh

phn ring c thc hin nhvch ngn xp, n cho nc i qua v gi

pha phn tn li. Qu trnh din ra di tc dng ca p sut ct nc.

Nc thi qua b lng ct c th gim c 50-60%SS.


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2.1.2. Phng php x l ha l

Nc thi ma ngcn cha nhiu cht hu c, cht v c dng ht c kch

thc nh, kh lng, kh c th tch ra bng cc phng php c hc thng thng

v tn nhiu thi gian v hiu qu khng cao. Ta c th p dng phng php keo t

loi b chng. Cc cht keo t thng s dng l phn nhm, phn st, phn

bn, kt hp vi polymer tr keo t tng qu trnh keo t.

Nguyn tc ca phng php ny l : cho vo trong nc thi cc ht keo mang

in tch tri du vi cc ht l lng c trong nc thi (cc ht c ngun gc silic v

cht hu c c trong nc thi mang in tch m, cn cc ht nhm hidroxid v st

hidroxy c a vo mang in tch dng). Khi th in ng ca nc b ph v,

cc ht mang in tri du ny s lin kt li thnh cc bng cn c kch thc ln

hn v d lng hn.

Phng php ny loi b c hu ht cc cht bn c trong nc thi . Tuy

nhin chi ph x l cao.

Phng php keo t

Keo t l qu trnh kt hp cc ht l lng khi cho cc cht cao phn

tvo nc. Khc vi qu trnh ng t, khi keo t th s kt hp din ra

khng ch do tip xc trc tip m cn do tng tc ln nhau gia cc phn

t cht keo t b hp ph trn cc ht l lng .

Cht keo tthng dng c th l hp cht t nhin v tng hp cht

keo t nhin l tinh bt, ete, xenluloz, dectrin (C6H10O5)n v dioxyt silichot tnh (xSiO2.yH2O).

Phng php tuyn ni

Phng php tuyn ni thng c s dng tch cc tp cht (

dng rn hoc lng) phn tn khng tan, t lng km ra khi pha lng.

Trong xl nc thi, tuyn ni thng c s dng kh cc cht l


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lng v lm c bn sinh hc. u im c bn ca phng php ny so vi

phng php lng l c th khc hon ton cc ht nh hoc nh, lng

chm, trong mt thi gian ngn. Khi cc ht ni ln b mt, chng c th

thu gom bng b phn vt bt.

Qu trnh tuyn ni c thc hin bng cch sc cc bt kh nh

(thng l khng kh ) vo trong pha lng. Cc kh kt dnh vi cc ht

v khi lc ni ca tp hp cc bng kh v ht ln s ko theo ht cng

ni ln b mt, sau chng tp hp li vi nhau thnh cc lp bt cha

hm lng cc ht cao hn trong cht lng ban u .

Phng php hp th

Phng php hp phc dng rng ri lm sch trit nc

thi khi cc cht hu c ho tan sau khi x l sinh hc cng nh x l cc

bkhi nc thi c cha mt hm lng rt nh cc cht . Nhng cht

ny khng phn hu bng con ng sinh hc v thng c c tnh cao.

Nu cc cht cn kh b hp ph tt v chi ph ring cho lng cht hp

ph khng ln th vic ng dng phng php ny l hp l hn c.

Cc cht hp phthng c s dng nh: than hot tnh, cc cht

tng hp v cht thi ca vi ngnh sn xut c dng lm cht hp ph

(tro, r, mt ca ). Cht hp phv c nh t st, silicagen, keo nhm

v cc cht hydroxit kim loi t c s dng v nng lng tng tc ca

chng vi cc phn tnc ln. Cht hp ph ph bin nht l than hot

tnh, nhng chng cn c cc tnh cht xc nh nh : tng tc yu vi cc

phn tnc v mnh vi cc cht hu c, c l xp th c th hp ph

cc phn t hu c ln v phc tp, c khnng phc hi. Ngoi ra, than

phi bn vi nc v thm nc nhanh. Quan trng l than phi c hot

tnh xc tc thp i vi phn ng oxy ha bi v mt s cht hu c trong

nc thi c khnng b oxy ho v b ho nha. Cc cht ho nha bt kn

l xp ca than v cn trvic ti sinh n nhit thp.


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Phng php trao i ion

Trao i ion l mt qu trnh trong cc ion trn b mt ca cht rn

trao i vi ion c cng in tch trong dung dch khi tip xc vi nhau.

Cc cht ny gi l cc ionit (cht trao i ion), chng hon ton khng tan

trong nc.

Cc cht c khnng ht cc ion dng t dung dch in ly gi l

cationit, nhng cht ny mang tnh axit. Cc cht c khnng ht cc ion

m gi l anionit v chng mang tnh kim. Nu nh cc ionit no trao

i c cation v anion gi l cc ionit lng tnh.

Phng php trao i ion thng c ng dng loi ra khi nc

cc kim loi nh: Zn, Cu, Cr, Ni, Pb, Hg, M ,vv, cc hp cht ca

Asen, photpho, Cyanua v cc cht phng x.

Cc cht trao i ion l cc cht v c hoc hu c c ngun gc t

nhin hay tng hp nhn to. Cc cht trao i ion v c t nhin gm c

cc zeolit, kim loi khong cht, t st, fenspat, cht mica khc nhau v c tng hp gm silicagen, pecmutit (cht lm mm nc ), cc oxyt

kh tan v hydroxyt ca mt s kim loi nh nhm, crm, ziriconi Cc

cht trao i ion hu c c ngun gc t nhin gm axit humic v than

chng mang tnh axit, cc cht c ngun gc tng hp l cc nha c b

mt ring ln l nhng hp cht cao phn t.


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2.1.3. Phng php x l sinh hc

Phng php ny da trn s hot ng ca cc vi sinh vt c kh nng phn

hy cc cht hu c. Cc vi sinh vt s dng cc cht hu c v mt s cht khong

lm ngun dinh dng v to nng lng. Ty theo nhm vi khun s dng l hiu

kh hay k kh m ngi ta thit k cc cng trnh khc nhau. V ty theo kh nng

v ti chnh, din tch t m ngi ta c th dng h sinh hc hoc xy dng cc b

nhn to x l.

C cc phng php sau:

- Phng php x l hiu kh :

Nc thi t cc hm cha c bm vo b iu ha. Cung cp oxy cho vi

sinh vt hiu kh c trong nc thi hot ng v pht trin. Cc vi sinh vt hiu kh

s dng cc cht hu c, cc ngun N v P cng vi mt s nguyn t vi lng khc

lm ngun dinh dng xy dng t bo mi, pht trin tng sinh khi. Bn cnh

qu trnh h hp ni bo cng din ra song song, gii phng CO 2v nc. C hai

qu trnh dinh dng v h hp ca vi sinh vt u cn oxy. p ng nhu cu oxyha tan trong nc, ngi ta thng s dng h thng sc kh b mt bng cch

khuy o hoc bng h thng kh nn.

T b iu ha, nc thi c a vo B sinh hc hiu kh c ha trn

vi bn vi sinh hot tnh to thnh hn hp vi sinh v nc thi. Vi sinh vt hiu

kh trong hn hp bn hot tnh s chuyn ha cc cht hu c trong nc thi di

dng thc n thnh cc hp cht n gin hn v v hi vi mi trng. Hn hp vi

sinh v nc thi c chy vo B lng, ni bn hot tnh c lng li v nn

y b. Bn lng c tun hon (khong 25-80 % tng lu lng) vo b sinh hc

hiu kh duy tr nng vi sinh n nh trong b.

S dng nhm vi sinh vt hiu kh, hot ng trong iu kin c oxy. Qu trnh

xl nc thi bng phng php hiu kh gm 3 giai on :


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


Oxy ha cc cht hu c :

CxHyOz + O2

Enzyme

CO2 + H2O +

HTng hp t bo mi :

CxHyOz + O2 + NH3 Enzyme

T bo vi khun (C5H7O2N) + CO2 + H2O -H

Phn hy ni bo :

C5H7O2N + O2 Enzyme

5CO2 + 2H2O + NH3 +H

Cng on x l cui cng l x l v thi b bn t b lng. Bn t b lngc bm vo b phn hy bn hiu kni phn hy cc hp cht hu c c trong

bn trong mi trng hiu kh.

Sau x l, bn ch cn cha cht v c v cc cht rn vi sinh .

Xl nc thi bng phng php sinh hc trong iu kin tnhin.

H sinh vt

H sinh vt l cc ao h c ngun gc t nhin hoc nhn to, cn gi

l h oxy ho, hn nh nc thi, xl nc thi bng phng php

sinh hc. Trong h sinh vt din ra qu trnh oxy ha sinh ha cc cht hu

c nhcc loi vi khun, to v cc loi thy sinh vt khc, tng tnh

qu trnh lm sch ngun nc mt. Vi sinh vt s dng oxy sinh ra t ru

to trong qu trnh quang hp cng nh oxy tkhng kh oxy ho cc

cht hu c, rong to li tiu th CO2, photphat v nitrat amon sinh ra t s

phn hu, oxy ho cc cht hu c bi vi sinh vt. h hot ng bnh

thng cn phi gi gi tr pH v nhit ti u. Nhit khng c thp

hn 60C.

Theo bn cht qu trnh sinh ho, ngi ta chia h sinh vt ra cc loi

h hiu kh, h sinh vt tu tin (Faculative) v h sinh vt ym kh.


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


H sinh vt hiu kh

Qu trnh xl nc thi xy ra trong iu kin y oxy, oxy c

cung cp qua mt thong v nh quang hp ca to hoc h c lm

thong cng bc nhcc h thng thit b cp kh. su ca h sinh vt

hiu kh khng ln t 0,5-1,5m.

H sinh vt tu tin

C su t 1.52.5m, trong h sinh vt ty tin, theo chiu su lp

nc c th din ra hai qu trnh: oxy ho hiu kh v ln men ym kh cc

cht bn hu c. Trong h sinh vt ty tin vi khun v to c quan h

tng hng vai tr c bn i vi s chuyn ha cc cht.

H sinh vt ym khC su trn 3m, vi s tham gia ca hng trm chng loi vi khun

k kh bt buc v k kh khng bt buc. Cc vi sinh vt ny tin hnh

hng chc phn ng ho sinh hc phn hu v bin i cc hp cht hu

c phc tp thnh nhng cht n gin, d x l. Hiu sut gim BOD

trong h c thln n 70%. Tuy nhin nc thi sau khi ra khi h vn c

BOD cao nn loi h ny ch ch yu p dng cho x l nc thi cng

nghip rt m c v dng lm h bc 1 trong t hp nhiu bc.

o Cnh ng ti - Cnh ng lc

Cnh ng ti l nhng khong t canh tc, c th tip nhn v x

l nc thi. X l trong iu kin ny din ra di tc dng ca vi sinh

vt, nh sng mt tri, khng kh v di nh hng ca cc hot ngsng thc vt, cht thi b hp th v gi li trong t, sau cc loi vi

khun c sn trong t s phn hu chng thnh cc cht n gin cy

trng hp th. Nc thi sau khi ngm vo t, mt phn c cy trng s

dng. Phn cn li chy vo h thng tiu nc ra sng hoc b sung cho

nc ngun.


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


Xl nc thi bng phng php sinh hc trong iu kin nhn to

B lc sinh hc

B lc sinh hc l cng trnh nhn to, trong nc thi c lc

qua vt liu rn c bao bc mt lp mng vi sinh vt. B lc sinh hc gm

cc phn chnh nh sau: phn cha vt liu lc, h thng phn phi nc

m bo ti u ln ton b b mt b, h thng thu v dn nc sau khi

lc, h thng phn phi kh cho b lc.

Qu trnh oxy ha cht thi trong b lc sinh hc din ra ging nh

trn cnh ng lc nhng vi cng ln hn nhiu. Mng vi sinh vt

s dng v xc vi sinh vt cht theo nc tri khi bc tch khi nc

thi b lng t 2. m bo qu trnh oxy ho sinh ha din ra n

nh, oxy c cp cho b lc bng cc bin php thng gi t nhin hoc

thng gi nhn to. Vt liu lc ca b lc sinh hc c th l nha Plastic,

x vng gm, Granit

B lc sinh hc nh git

B c dng hnh vung, hnh ch nht hoc hnh trn trn mt bng,

b lc sinh hc nh git lm vic theo nguyn tc sau :

Nc thi sau b lng t 1 c a v thit b phn phi, theo chu k

ti u nc trn ton b b mt b lc. Nc thi sau khi lc chy vo h thng

thu nc v c dn ra khi b. Oxy cp cho b ch yu qua h thng l xung

quanh thnh b. Vt liu lc ca b sinh hc nh git thng l cc ht cui,

ng knh trung bnh 2030 mm. Ti trng nc thi ca b thp (0,51,5 m3/m3

vt liu lc /ngym). Chiu cao lp vt liu lc l 1.52m. Hiu qu xl nc

thi theo tiu chun BOD t 90%. Dng cho cc trm xl nc thi c cng sut

di 1000 m3/ngym.


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


B lc sinh hc cao ti

B lc sinh hc cao ti c cu to v qun l khc vi b lc sinh hc

nh git, nc thi ti ln mt b nhh thng phn phi phn lc. B c

ti trng 10 20 m3nc thi/1m2b mt b /ngym. Nu trng hp

BOD ca nc thi qu ln ngi ta tin hnh pha long chng bng nc

thi lm sch. B c thit k cho cc trm x l di 5000

m3/ngym

B aerotank

Ty thuc vo loi cht nhim c th s dng b aerotank vi cc vi sinh vt

c nui cy trong bn hot tnh oxy ha cht hu c trong iu kin nhn to.M hnh ny c thc hin bng cch cung cp oxy cho vi sinh vt sinh trng v

pht trin qua vic tiu th cht hu c .Bn hot tnh l loi bn xp cha nhiu vi sinh vt c kh nng oxy ha v

khong ha cht hu c cha trong nc thi. gi cho bn hot tnh trng thil lng v m bo oxy cho vi sinh vt s dng trong qu trnh phn hy cht huc phi lun cung cp y khng kh cho b aerotank hot ng. Sau b aerotanknc thi vo b lng t 2 tch bn hot tnh. y, mt phn bn lng ca tr li b aerotank to mm vi sinh vt trong b, phn khc a ti b nn

bn.Khi lng bn tun hon v lng khng kh cn cung cp ph thuc vo mc

yu cu x l ca nc thi.Hiu qu x l BOD5 =90-95%.Vic la chn cng ngh x l ty theo thnh phn tnh cht nc thi, chi ph

u t qun l v din tch mt bng khu x l .

-Phng php x l k kh:

S dng vi sinh vt k kh, hot ng trong iu kin ym kh khng

hoc c lng O2ha tan trong mi trng rt thp, phn hy cc cht

hu c.

Bn giai on xy ra ng thi trong qu trnh phn hy k kh :

Thy phn : Trong giai on ny, di tc dng ca enzyme do vi khun tit ra,

cc phc cht v cc cht khng tan (nh polysaccharide, protein, lipid) chuyn


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SVTH: Nguyn Th Soa


ha thnh cc phc cht n gin hn hoc cht ha tan (nh ng, cc acid

amin, acid bo).

Acid ha : Trong giai on ny, vi khun ln men chuyn ha cc cht ha tan

thnh cht n gin nh acid bo dbay hi, ru, acid lactic, methanol, CO2,H2, NH3, H2S v sinh khi mi.

Acetic ha : Vi khun acetic chuyn ha cc sn phm ca giai on acid ha

thnh acetat, H2, CO2 v sinh khi mi.

Methane ha: y l giai on cui ca qu trnh phn hy k kh. Acid acetic,

H2, CO2, acid formic v methanol chuyn ha thnh methane, CO2 v sinh khi

mi.

B UASB

UASB l b x l sinh hc k kh dng chy ngc qua lp bn, phttrin mnh H Lan. X l bng phng php k kh l phng php cng dng x l cc loi cht thi c hm lng hu c tng i cao,kh nng phn hy sinh hc tt, nhu cu nng lng thp v sn sinh nnglng mi.

V qu trnh phn hy k kh di tc dng ca bn hot tnh l qu

trnh sinh hc phc tp trong mi trng khng c oxi, nn bn nui cyban u phi c hot tnh methane. hot tnh methane cng cao ththi gian khi ng (thi gian vn hnh ban u t n ti trng thit k)cng ngn. Bn hot tnh dng cho b UASB nn ly bn ht hoc bn lyt mt b x l k kh l tt nht, c th s dng bn cha nhiu cht huc nh bn t b t hoi, phn gia sc hoc phn chung.

B UASB l mt b x l vi lp bn di y, c h thng tch v thu kh,

nc ra pha trn. Khi nc thi c phn phi t pha di ln s i qua lp bn,

cc vi sinh vt k kh c mt cao trong bn s phn hy cc cht hu c c trongnc thi. Bn trong b UASB c cctm chn c kh nng tch bn b li ko theo

nc u ra.

C ba qu trnh phn hy - lng bn - tch kh c lp t trong cng mt

cng trnh. Sau khi hot ng n nh trong b UASB hnh thnh loi bn ht c mt

vi sinh rt cao, hot tnh mnh v tc lng vt xa so vi bn hot tnh hiu

kh dng l lng.


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


B sinh hc theo m SBR

H thng x l sinh hc tng m bao gm a nc thi vo b phn ng v to

cc iu kin cn thit nh mi trng thiu kh (khng c oxy, ch c NO3-), k kh

(khng c oxy), hiu kh (c oxi, NO3- ) cho vi sinh tng sinh khi, hp th v

tiu ha cc cht thi hu c trong nc thi.

Cht thi hu c (C,N,P) t dng ha tan s chuyn ha vo sinh khi

vi sinh v khi lp sinh khi vi sinh ny lng kt xung s cn li nc trong

tch cht nhim, chu k x l trn li tip tc cho mt mnc thi

mi.

Thc cht ca phng php ho hc l a vo nc thi cht phn ng no gy tc

ng vi cc tp cht bn, bin i ho hc v to cn lng hoc to cc dng cht ho tan

nhng khng c hi, khng gy nhim mi trng. Theo giai on v mc x l,

phng php ho hc s c tc dng tng cng qu trnh x l c hc hoc sinh hc.

Nhng phn ng din ra trong qu trnh ny c th l phn ng oxyho kh, cc phn ng

kt hp to kt ta, phn ng trung ho, phn ng phn hu cc cht c hi.

2.1.4. Phng php ha hc

Phng php Ozone ho

L phng php x l nc thi c cha cc cht v c dng ho tan v dng

keo bng ozone. Ozone d dng nhng oxy nguyn t cho cc tp cht hu c

Phng php trung ho

Dng a mi trng nc thi c cha cc axid v c hoc kim v dng

trung tnh c pH = 6,57,5. Phng php ny c th thc hin bng nhiu cch: trnln nc thi c tnh acid vi nc thi c tnh baz; b sung thm cc tc nhn ho

hc; lc qua lp vt liu lc c tc dng trung ho, hp ph kh cha axid bng nc

thi cha kim,


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


CHNG III: LA CHN CNG NGH XL

3.1. C sla chn cng nghBng 2:Thnh phn, tnh cht nc thi ca nc thi ma ng

Ch tiu Nng n v QC ngun

thi loi B

Gi tr Cmax

pH 7,5-8 mg/l 5,5-9 5,5*1,0*1,0=5,5

SS 1250 mg/l 100 100*1,0*1,0=100

BOD55000 mg/l 50 50*1,0*1,0=50

COD 7000 mg/l 100 100*1,0*1,0=100

N-tng 16,4 mg/l 30 30*1,0*1,0=30

P- tng 7,5 mg/l 6 6*1,0*1,0=6

Nhn xt:

-pH t tiu chun x thi .

- SS vt tiu chun x thi 12,5 ln .

- BOD5vt tiu chun x thi 100 ln.

- COD vt tiu chun x thi 70 ln.

- P- tng vt tiu chun x thi 1,25 ln.

Lulng u vo:1000m3/ ngy. Ta chn b lng ng

Mc x l cn thit:

p dng cng thc: %1000

0

S

SSE

Trong :S0l nng cht ban u

S l nng tiu chun x thi loi B


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


Bng 3: Mc x l cn thit

Ch tiu E

SS 90%1001250

1001250

%

BOD5 %99%1005000

505000

COD%100

7000

1007000

=98,6%

P-tng%20%100

5,7

65,7

Ngun tip nhn: sng Vm C ng vi lu lng l 96m3/s.


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SVTH: Nguyn Th Soa



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27/33

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SVTH: Nguyn Th Soa


Thuyt minh s cng ngh 1:

Nc thi sn xut c dn theo ng thot nc ring ra h thng x l

nc thi.Dng thi qua song chn rc loi b mt phn cht thi th ra khi ncthi.Phn rc thu c c th x l chn lp. nc thi sau khi qua song chn rcc cho vo hm bm tip nhn . Tip theo, nc thi c bm qua b iu ha,lu lng v nng nc thi ra s c iu ha n nh. Ti y nc thi cthi kh lm thong s b v phn b cht bn ng ukhp b. Sau tip tc

bm nc thi qua b lng 1 loi b 1 phn BOD5 , COD v SS.Tip tc, ncthi t chy qua b k kh kiu m bn chy ngc UASB x l s b nh p lcthy tnh , v nc thi ma ng c c trng l COD u vo rt ln 7000 mg/l .Sau khi x l ym kh, u ra b UASB l kh sinh hc c thu gi li lm biogas

phc v cho qu trnh sn xut ng ma. K tip, nc thi c dn vo bbiophin c s dng lp vt liu lc khi nc thi qua lp vt liu lc to ra mng visinh vt pha trn b mt vt liu lc, mng ny c tc dng hp th cht hu cthkh CO2, H2S.nc thi chy qua b lng ng lng mt s cht hu c cn lihay l bn. Cui cng sc kh clo vo b tip xc a nc thi t loi B v thira sng Vm C ng.


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Thuyt minh s cng ngh 2:Nc thi sn xut c dn theo ng thot nc ring ra h thng x l

nc thi.Dng thi sau khi qua song chn rc u mi cng thu chy qua b lngct c t su di t, y s gi li ct v cc cht rn l lng c kch thcln . Phn rc thi thu c c th dng lmphn bnNc thi sau khi lng ct st chy qua hm tip nhn. Tip theo,nc thi c bm qua b iu ha gi lulng v nng nc thi ra s c iu ha n nh. Ti y nc thi c thikh lm thong s b v phn b cht bn ng u khp b. Sau tip tc bmnc thi qua b lng 1 loi b 1 phn BOD5 , COD v SS.Tip tc, nc thi tchy qua b k kh kiu m bn chy ngc UASB x l s b nh p lc thytnh , v nc thi ma ng c c trng l COD u vo rt ln 7000 mg/l . Sau

khi x l ym kh, u ra b UASB l kh sinh hc c thu gi li lm biogas , phnnc c gim bt ti lng cht hu c t chy qua aerotank x l hiu kh .Ti y xy ra qu trnh x l sinh hc , kh c thi vo b bng cc a phn phikh nhm tng cng s xo trn cht bn v oxi trong khng kh ng thi gi cho

bn trng thi l lng . Sau thi gian lu, nc t aerotank t chy qua b lngng lng bn .Tip theo, nc trong t mng thu nc aerotank t chy qua khtrng bng Clo tiu dit vi sinh vt .Bn t b lng c a vo b cha bn saukhi n nh bn c bm tun hon 1 phn vo b aerotank, phn cn li bm qua

b nn bn trng lc sau bm qua my p bn, bn sau khi ra khi my p bn

to thnh bnh bn c bn rung, trng cy hoc chn lp hp v sinh . Nc saux l t loi B dng cho ti cy ra sng Vm C ng .


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So snh hai quy trnh cng ngh:

Tiu ch Quy trnh cng ngh 1 Quy trnh cng ngh 2

u im - n gin, d lm- B biophin c mng vi

sinh vt hp th cc cht hu c khtt trong nc thi.

- Sinh ra lng kh CH4ln

- B aeroten dng vicng sut ln hn b

biophin.- Hiu qu x l cao- Tnh ph bin.- Din tch mt bng

tng i nh.

- D vn hnhNhc im - Cng sut b biophin

kh nh.- Mng vi sinh vt d b

rch.- Din tch xy dng ln.- Kh vn hnh.- C mi kh chu

- Lng bn d , kh litrong b kh ln.

Kt lun: t 2 cng ngh ta thy c cng ngh 2 c tnh kh thi hn va d thitk, d vn hnh li va t hiu qu x l cao hn so vi cng ngh 1. Nn ta acng ngh 2 vo thit k v xy dng.


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SVTH: Nguyn Th Soa


CHNG IV: TNH TON CNG TRNH XL

4.1. Tnh ton b lng ng

Din tch tit din t ca ng trung tm c tnh theo cng thc:

03,0360024

1000max

ttv

Qf =0,386 m2.

Trong , Qmax=1000m3/24h.

Vtt- tc chuyn ng ca nc trong ng trung tm,

chn vtt=0,03m/s.

Din tch tit din t ca b lng ng trong mt bng tnh theo cng thc:

81,17105,6360024

10004

max

v

Qf m2.

Chn f=18 m2.

Trong , v l tc chuyn ng ca nc thi trong b lng ng, theo quyphm (v=0,5-0,8 mm/s), chn v=0,65mm/s= 6,5*10-4.

Chn 2 b lng ng v din tch mi b trong mt bng:

2,9

2

386,0181

n

fFF m2.

Trong , n- s b lng ng, chn n= 2

ng knh mi b:

4,32,944 1

FD m.

Din tch tit din ng trung tm ca 1 b

193,02

386,0

21

ff m2.

ng knh ng trung tm

mf

d 5,0193,044 1

Chiu cao tnh ton ca vng lng trong b lng ng.7,236005,1105,0 3 mtvhtt

Trong , t- thi gian lng. chn t=1,5h.

Chiu cao ng trung tm bng chiu cao vng lng v bng 2.7 m.


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Xl nc thi ma ng

SVTH: Nguyn Th Soa


Chiu cao phn hnh nn ca b lng ng c xc nh

.67,150)2

6,04,3()

2( 032 mtgtg

dDhhh nn

Trong , h2 l chiu cao lp trung ha

h3- chiu cao ginh ca lp cn lng trong b

D- ng knh trong ca b lng

dn- ng knh y nh ca hnh nn ct , dn=0,6 m

- gc nghing ca y b lng so vi phng ngang, 050

Htt=Htnh ton vng lng= 2.7m.ng knh ming lc ca ng trung tm= Hng lc=1,35Dtt.

hl= 1,35*d=1,35*0,5=0,675 m.ng knh tm chn=1,3Dloe=1,3*0,675=0,88 m.Khong cch gia mp ngoi cng ca ming loe n mp ngoi cng ca b

mt tm chn theo mt phng qua trc

.08,2)6,04,3(02,0360024

10004

)(

4m

dDV

QL

nK

Trong , vktc dng nc chy qua khe hgia ming loe ngtrung tm v b mt tm chn , chn vk= 20mm/s.

chiu cao tng cng ca b lng ngH=htt+hn+h0=htt+(h2+h3)+h0=2,7+1,67+0,3= 4,67 m.

Trong , h0 l khong cch t mc nc n thnh b , chn h0=0,3m.

Mng rng ca :

Mng rng ca c gn vo mng thu nc (qua lp m cao su) iu

chnh cao mp mng thu m bo thu nc u trn ton b chiu di

mng trn.

Bdy mng rng ca l 5 mm.

Chiu cao tng cng ca mng rng ca 260mm.

Chiu di mng rng ca bng chiu di mng thu nc :

mll m 1


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Ti trng thu nc trn 1 m di mp mng :

ngy

m

L

QA

2

77,48008,2

1000

Mng rng ca xkhe thu nc ch V , gc 90oiu chnh cao

mp mng :

Chiu cao khe : 60 mm.

B rng mi khe l 60 mm.

1 m chiu di c 20 khe ch V.

Khong cch gia cc nh l 40mm.

Tng s khe chV trn mng rng ca :

)(2020120 kheln

Lu lng nc qua 1 khe chV gc y 900 :

)/(05,0)/(5020

1000

20

3

0 smslQ

q .

Chiu cao mc nc qua khe ch V :

mq

hhq 47,04,1

05,0

4,14,1 5,25,2 0

5,2

0

Mng rng ca c bt dnh vi mng thu nc b tng bngbulng qua cc khe dch chuyn .

Khe dch chuyn c ng knh 10 mm, bulng c bt cch mpdi mng rng ca 50mm v cch y ch V l 50mm. Hai khedch chuyn cch nhau 0,5m.


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KT LUN

Nh chng ta bit ngnh ma ng gp phn khng nh vo stngtrng kinh t ca nc ta. Tuy nhin. Nc thi ngnh ny cng thi ra khng t

cht nu khng c x l kp thi v trit s gy nhim mi trng do cnphi thit k, xy dng h thng x l nc thi t quy chun x thi ; khng lmmt i khnng t lm sch ca ngun nc.

Nc thi ma ng c tnh cht chung l nng cht hu c cao v vytrong cng ngh xl i hi phi c b phn hy cht hu c. B UASB VAerotank c hiu qu x l cht hu c rt cao. Kt hp 2 b ny trong h thng thxl c gn nh l hon ton. xl nc thi ma ng cn qua nhiu cngtrnh x l ch khng phi mt mnh 2 bny nh h thng xl ti ni trn , lm gim bt nng cht hu c.

Khi thit k b, c bit l aerotank cn phi cung cp y oxy khuy ucht hu c trong nc thi v cung cp y bn hot tnh cho b.

TI LIU THAM KHO

1. GS.TS.Lm Minh Trit, tnh ton thit k cng trnh x l nc thi th v cng nghip, Nh xut bn i hc quc gia Thnh Ph H ChMinh.

2. Ng Th Nga,gio trnh cng ngh xl nc thi , nh xut bn khoa

hc v k thut H Ni 2006.3. n xl nc thi ma ng ,http://www.yeumoitruong.com.
http://www.yeumoitruong.com/http://www.yeumoitruong.com/http://www.yeumoitruong.com/http://www.yeumoitruong.com/

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