MC LCCHNG 1: M U................................................................................................. 1 1.1. Gii thiu................................................................................................................. 1 1.2. Tnh cp thit ca ti .......................................................................................... 1 1.3. Mc tiu nghin cu ................................................................................................ 2 1.4. Ni dung nghin cu............................................................................................... 2 1.5. Phm vi nghin cu................................................................................................. 2 CHNG 2: TNG QUAN .......................................................................................... 3 2.1. Thnh phn, tnh cht ca nc thi chn nui....................................................... 3 2.1.1. Cc cht hu c v v c..................................................................................... 3 2.1.2. N v P................................................................................................................... 3 2.1.3. Vi sinh vt gy bnh............................................................................................. 3 2.2. Cc nghin cu trong v ngoi nc v x l nc thi chn nui heo................. 3 2.2.1. Cc nc trn th gii .......................................................................................... 3 2.2.2. Vit Nam .......................................................................................................... 5 CC QUY TRNH X L CHT THI CHN NUI THAM KHO ........................ 6 i vi quy m h gia nh ................................................................................................ 6 i vi c s chn nui quy m nh................................................................................. 7 i vi c s chn nui quy m va v ln .................................................................. 7 2.3. Cc phng php x l nc thi chn nui heo .................................................... 8 2.3.1. Phng php x l c hc .................................................................................... 8 2.3.2. Phng php x l ha l .................................................................................... 9 2.3.3. Phng php x l sinh hc............................................................................... 10 2.3.3.1. Phng php x l hiu kh........................................................................... 10 2.3.3.2. Phng php x l k kh .............................................................................. 10 2.3.3.3. Cc h thng x l nhn to bng phng php sinh hc............................... 11 2.3.3.4. Cc h thng x l t nhin bng phng php sinh hc............................... 14 2.3.3.5. ng dng thc vt nc x l nc thi................................................... 18 2.3.3.6. ng dng lc bnh x l nc thi ............................................................ 19 CHNG 3: XUT CC PHNG N X L NC THI CHN NUI HEO CNG SUT 500M3/NGY M................................................................... 24 3.1. C s la chn phng n x l nc thi........................................................... 24 3.2. Phng n 1........................................................................................................... 25 3.3. Phng n 2 .......................................................................................................... 26 CHNG 4: TNH TON CHI TIT CC CNG TRNH N V THEO PHNG N 2........................................................................................................... 28 4.1. Li chn rc......................................................................................................... 28 4.2. Ngn tip nhn....................................................................................................... 29 4.3. B lng ct............................................................................................................. 30 4.4. B iu ha ............................................................................................................ 31 4.5. B lng t I .......................................................................................................... 36 4.6. B UASB............................................................................................................... 40 4.7. B aerotank ............................................................................................................ 43 4.8. B lng II............................................................................................................... 53 4.9. B nn bn............................................................................................................. 57 4.10. My p bn .......................................................................................................... 60 4.11. H sinh hc thc vt ............................................................................................ 61 CHNG 5: TNH KINH T..................................................................................... 63 n mn hc X L Nc Thi Lp HMT1CHNG 1: M U CHNG 1: M U1.1. Gii thiu 1.1. Gii thiuT ngn nm nay cuc sng ca ngi nng dn Vit Nam gn lin vi cy la v chn nui gia sc. Chn nui heo khng ch cung cp phn ln tht tiu th hng ngy, l ngun cung cp phn hu c cho cy trng, m chn nui heo cn tn dng thc n v thu ht lao ng d tha trong nng nghip. Vi nhng c tnh ring ca n nh tng trng nhanh, vng i ngn chn nui heo lun c quan tm v n tr thnh con vt khng th thiu c ca cuc sng hng ngy trong hu ht cc gia nh nng dn. Trong nhng nm gn y i sng ca nhn dn ta khng ngng c ci thin v nng cao, nhu cu tiu th tht trong ch yu l tht heo ngy mt tng c v s lng v cht lng thc y ngnh chn nui heo bc sang bc pht trin mi. Hin nay trn c nc ta xy dng nhiu m hnh chn tri chn nui heo vi quy m ln, ch yu phn b ti 5 vng trng im l Mc Chu (Sn La), H Ni v cc vng ph cn, khu vc TPHCM v cc tnh xung quanh, Lm ng v mt s tnh duyn hi min Trung.Bn cnh nhng mt tch cc, vn mi trng do ngnh chn nui gy ra ang c d lun v cc nh lm cng tc mi trng quan tm. cc nc c nn chn nui cng nghip pht trin mnh nh H Lan, Anh, M, Hn Quc, th y l mt trong nhng ngun gy nhim ln nht. Vit Nam, kha cnh mi trng ca ngnh chn nui ch c quan tm trong vi nm tr li y khi tc pht trinchnnuingycngtng, lngchtthidochnnuiavomi trng ngy cng nhiu, e da n mi trng t, nc, khng kh xung quanh mt cch nghim trng.1.2. Tnh cp thit ca ti 1.2. Tnh cp thit ca tiNgun nc thi chn nui l mt ngun nc thi c cha nhiu hp cht hu c, virus, vi trng, trng giun sn Ngun nc ny c nguy c gy nhim cc tng nc mt, nc ngm v tr thnh nguyn nhn trc tip pht sinh dch bnh cho n gia sc. ng thi n c th ly lan mt s bnh cho con ngi v nh hng n mi trng xung quanh v nc thi chn nui cn cha nhiu mm bnh nh:Samonella, Leptospira, Clostridium tetani,nu khng x l kp thi. GVHD: ThS. Nguyn Xun Hon Trang 1 n mn hc X L Nc Thi Lp HMT1Bn cnh cn c nhiu loi kh c to ra bi hot ng ca vi sinh vt nh NH3, CO2, CH4, H2S, . . .Cc loi kh ny c th gy nhim c khng kh v ngun nc ngm nh hg n i sng con ngi v h sinh thi. Chnh v vy m vic thit k h thng x l nc thi cho cc tri chn nui heo l mt hot ng ht sc cn thit.1.3. Mc tiu nghin cu 1.3. Mc tiu nghin cuXc nh cc ch tiu ho l ca nc thi chn nui lm c s cho vic xut cc phng n x l v la chn phng n kh thi nht tnh ton thit k.1.4. Ni dung nghin cu 1.4. Ni dung nghin cuXc nh thnh phn, mt s ch tiu ha l, ca nc thi chn nui.Thu thp cc thng tin v cc phng php x l nc thi chn nui heo t cc ti liu. xut cc dy chuyn x l nc thi chn nui heo v la chn phng n kh thi nht.Tng hp s liu, tnh ton thit k cc cng trnh n v.1.5. Phm vi nghin cu 1.5. Phm vi nghin cuCh p dng cho x l nc thi chn nui heo cng sut 500m3/ng. Khng p dng cho nc thi cc ngnh khc. Cht thi rn v kh khng tnh n trong n ny.GVHD: ThS. Nguyn Xun Hon Trang 2 n mn hc X L Nc Thi Lp HMT1CHNG 2: TNG QUAN CHNG 2: TNG QUAN2.1. Thnh phn, tnh cht ca nc thi chn nui 2.1. Thnh phn, tnh cht ca nc thi chn nuiNc thi chn nui l mt trong nhng loi nc thi rt c trng, c kh nng gy nhim mi trng cao bng hm lng cht hu c, cn l lng, N, P v sinh vt gy bnh. N nht thit phi c x l trc khi thi ra ngoi mi trng. La chn mt quy trnh x l nc thi cho mt c s chn nui ph thuc rt nhiu vo thnh phn tnh cht nc thi, bao gm:2.1.1. Cc cht hu c v v c 2.1.1. Cc cht hu c v v cTrong nc thi chn nui, hp cht hu c chim 7080% gm cellulose, protit, acid amin, cht bo, hidratcarbon v cc dn xut ca chng c trong phn, thc n tha. Hu ht cc cht hu c d phn hy. Cc cht v c chim 2030% gmct, t, mui, ure, ammonium, mui chlorua, SO42-, 2.1.2. N v P 2.1.2. N v PKh nng hp th N v P ca cc loi gia sc, gia cm rt km, nn khi n thc n c cha N v P th chng s bi tit ra ngoi theo phn v nc tiu. Trong nc thi chn nui heo thng cha hm lng N v P rt cao. Hm lng N-tng trong nc thi chn nui 571 1026 mg/L, Photphot 39 94 mg/L. 2.1.3. Vi sinh vt gy bnh 2.1.3. Vi sinh vt gy bnhNc thi chn nui cha nhiu loi vi trng, virus v trng u trng giun sn gy bnh. 2.2. Cc nghin cu trong v ngoi nc v x l nc thi chn nui heo 2.2. Cc nghin cu trong v ngoi nc v x l nc thi chn nui heo2.2.1. Cc nc trn th gii 2.2.1. Cc nc trn th gii Chu , cc nc nh: Trung Quc, Thi Lan, l nhng nc c ngnh chn nui cng nghip ln trong khu vc nn rt quan tm n vn x l nc thi chn nui.GVHD: ThS. Nguyn Xun Hon Trang 3 n mn hc X L Nc Thi Lp HMT1Nhiu nh nghin cu Trung Quc tm ra nhiu cng ngh x l nc thi thch hp nh l: K thut lc ym kh K thut phn hy ym kh hai giai on B Biogas t hoiHin nay Trung Quc cc b Biogas t hoi s dng rng ri nh phn ph tr cho cc h thng x l trung tm. B Biogas l mt phn khng th thiu trong cc h gia nh chn nui heo va v nh cc vng nng thn, n va x l c nc thi v gim mi hi thi m cn to ra nng lng s dng.Trong lnh vc nghin cu x l nc thi chn nui heo ti Thi Lan th trng i hc Chiang Mai c nhiu ng gp rt ln.- HYPHI (h thng x l tc cao kt hp vi h thng chy nt): h thng HYPHI gm c thng lng, b chy nt v b UASB. Phn heo c tch lm 2 ng, ng th nht l cht lng c t cht rn tng s, cn ng th hai l phn cht rn vi nng cht rn tng s cao, k thut ny c xy dng cho cc tri heo trung bnh v ln. Nga cc nh nghin cu cng nghin cu x l nc thi phn heo, phn b di cc iu kin a lnh v a nng trong iu kin kh hu Nga.Mt s tc gi c cho rng chin lc gii quyt vn x l nc thi chn nui heo l s dng k thut SBR (sequencing batch reactor). i vi cc loi nc thi giu Nit v Phospho nh nc thi chn nui heo th cc phng php x l thng thng khng th t c cc tiu chun cho php v hm lng v Nit v Phospho trong nc ra sau x l. Cng ngh x l nc thi chn nui giu cht hu c a ra l SBR c th gim trn 97% nng COD, Nit, Phospho.Nhn xt chung v cng ngh x l nc thi giu cht hu c sinh hc trn th gii l p dng tng th v ng b cc thnh tu k thut ln men ym kh, ln men hiu kh v ln men thiu kh, nhm p ng cc yu cu kinh t x hi v bo v mi trng. Trn c s c th xut ra nhng gii php k thut ph hp vi tng iu kin sn xut c th. S khi qut sau y l c s la chn m hnh x l thch hp.GVHD: ThS. Nguyn Xun Hon Trang 4 n mn hc X L Nc Thi Lp HMT1Hnh 2.1: S tng qut x l nc thi giu cht hu c sinh hc2.2.2. Vit Nam 2.2.2. Vit Nam Vit Nam, nc thi chn nui heo c coi l mt trong nhng ngun nc thi gy nhim nghim trng. Vic m rng cc khu dn c xung quanh cc x nghip chn nui heo nu khng c gii quyt tha ng s gy ra nhim mi trng nh hng n sc khe cng ng v gy ra nhng vn mang tnh cht x hi phc tp.Nhiu nguyn cu trong lnh vc x l nc thi chn nui heo ang c ht sc quan tm v mc tiu gii quyt vn nhim mi trng, ng thi vi vic to ra nng lng mi. Cc nghin cu v x l nc thi chn nui heo Vit Nam ang tp trung vo hai hng chnh, hng th nht l s dng cc thit b ym kh tc thp nh b ln mem to kh Biogas kiu Trung Quc, n , Vit Nam, hoc dng cc ti PE. Phng hng th nht nhm mc ch xy dng k thut x l ym kh nc thi chn nui heo trong cc h gia nh chn nui heo vi s u heo khng nhiu. Hng th hai l xy dng quy trnh cng ngh v thit b tng i hon chnh, ng b nhm p dng trong cc x nghip chn nui mang tnh cht cng nghip. Trong cc nghin cu v quy trnh cng ngh x l nc thi chn nui heo cng nghip a ra mt s kin ngh sau:Cng ngh x l nc thi chn nui cng nghip c th tin hnh nh sau: (1) x l c hc: lng 1; (2) x l sinh hc: bt u bng sinh hc k kh UASB, tip theo l sinh hc hiu kh (Aerotank hoc h sinh hc); (3) kh trng trc khi thi ra ngoi mi trng.Nhn chung nhng nghin cu ca chng ta i ng hng, tip cn c cng ngh th gii ang quan tm nhiu. Tuy nhin s lng nghin cu v cht lng cc nghin cu ca chng ta cn cn c nng cao hn, nhm nhanh chng c p dng trong thc t sn xut.GVHD: ThS. Nguyn Xun Hon Trang 5B lngNc ra Nc thi voB iu haBn, cnPhn hy ym kh tc thpUASBThp lc ym khPhn hy ym kh tip xcLc hiu kh v thiu khRBCLc hiu khAEROTANKH thc vt thy sinhBnMc tiu kt qu ch yuX l ym kh X l hiu kh1) 90%BOD Biogas2) 99% mm bnh b dit3)N,P,K cn nguyn1) N, P, K v cc loi yu t gy c2) Tip tc gim COD v BOD n mn hc X L Nc Thi Lp HMT1CC QUY TRNH X L CHT THI CHN NUI THAM KHOi vi quy m h gia nhDo lng cht thi chn nui thi ra hng ngy cn t nn cc c s chn nui h gia nh c th thu gom qut dn chung thng xuyn. C th p dng mt s bin php x l cht thi theo cc s sau :Quy trnh1:

Quy trnh 2: GVHD: ThS. Nguyn Xun Hon Trang 6CN LNGH GA PHNB T HOINC THI X L THI RA NGUNNCTHICHN NUIPHN BNPHNHM BIOGAS H LNGNCTHICHN NUINC THI X L THI RA NGUNBIOGASLNG PHNB SC KH UASB LNGPHN BNTHI RA NGUNPHNNC THICHN NUI n mn hc X L Nc Thi Lp HMT1i vi c s chn nui quy m nhTi cc c s chn nui quy m nh, lng phn gia sc thi ra hng ngy khong vi trm kg, do vic s dng ti hoc biogas x l phn l khng kh thi v tn rt nhiu din tch v cng xy dng. Trng hp ny ta c th tch ring qu trnh x l phn v nc thi. Nc thi chn nui c x l bng h thng biogas, phn c thu gom v x l ring bng qu trnh lm phn bn. Cn lng t khu x l nc thi c thu gom x l chung vi phn v nc r trong qu trnh phn c th a ngc tr li h thng x l nc thi.Quy trnh:

i vi c s chn nui quy m va v ln i vi c s chn nui quy m va v lnVi quy m va tr ln, vic u t cho mt h thng x l cht thi chn nui l c th thc hin c. Ty vo trng hp c th m c th p dng mt s quy trnh sau y:Quy trnh 1:Quy trnh2:GVHD: ThS. Nguyn Xun Hon Trang 7NC THI CHN NUIHM BIOGAS H LNG PHNNC THI X L THI RA NGUNCN LNGPHN BNPHN n mn hc X L Nc Thi Lp HMT1 i vi cc c s chn nui c quy m ln, rt ngn thi gian x l v tng hiu qu x l, c th thm khu tin x l trc khu x l sinh hc hoc kt hp x l sinh hc vi x l bc cao.2.3. Cc phng php x l nc thi chn nui heo 2.3. Cc phng php x l nc thi chn nui heoVic x l nc thi chn nui heo nhm gim nng cc cht nhim trong nc thi n mt nng cho php c th x vo ngun tip nhn. 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. Cc iu kin ca tri chn nui. Hiu qu x l.i vi nc thi chn nui, c th p dng cc phng php sau : Phng php c hc. Phng php ha l. Phng php sinh hc.Trong cc phng php trn ta chn x l sinh hc l phng php chnh. Cng trnh x l sinh hc thng c t sau cc cng trnh x l c hc, ha l.2.3.1. Phng php x l c hc 2.3.1. Phng php x l c hcMc 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, b lng s b loi b cn th, d GVHD: ThS. Nguyn Xun Hon Trang 8LNGH K KH PHNH TYNGHIH HIU KHTHI RA NGUNPHN BN PHNNC THI CHN NUI n mn hc X L Nc Thi Lp HMT1lng to iu kin thun li v gim khi tch ca cc cng trnh x l tip theo. Ngoi ra c th dng phng php ly tm hoc lc. Hm lng cn l lng trong nc thi chn nui kh ln (khong vi ngn mg/L) v d lng nn c th lng s b trc ri a sang cc cng trnh x l pha sau.Sau khi tch, nc thi c a sang cc cng trnh pha sau, cn phn cht rn c em i lm phn bn.2.3.2. Phng php x l ha l 2.3.2. Phng php x l ha lNc thi chn nui cn 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 tcca phng php nyl :cho votrong nc thi cc htkeo mang in tch tri du vi cc ht l lng c trong nc thi (cc ht c ngun gc silicvcht hucctrongncthi mangintchm, cnccht nhm hidroxid v st hidroxi 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.Theo nghin cu ca Trng Thanh Cnh (2001) ti tri chn nui heo 2/9: phng php keo t c th tch c 80-90% hm lng cht l lng c trong nc thi chn nui heo.Ngoi keo t cn loi b c P tn ti dng PO43-do to thnh kt ta AlPO4 v FePO4.Phng php ny loi b c hu ht cc cht bn c trong nc thi chn nui. Tuy nhin chi ph x l cao. p dng phng php ny x l nc thi chn nui l khng hiu qu v mt kinh t.Ngoi ra, tuyn ni cng l mt phng php tch cc ht c kh nng lng km nhng c th kt dnh vo cc bt kh ni ln. Tuy nhin chi ph u t, vn hnh cho phng php ny cao, cng khng hiu qu v mt kinh t i vi cc tri chn nui.GVHD: ThS. Nguyn Xun Hon Trang 9 n mn hc X L Nc Thi Lp HMT12.3.3. Phng php x l sinh hc 2.3.3. Phng php x l sinh hcPhng 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. 2.3.3.1. Phng php x l hiu kh 2.3.3.1. Phng php x l hiu khS dng nhm vi sinh vt hiu kh, hot ng trong iu kin c oxy. Qu trnh x l nc thi bng phng php hiu kh gm 3 giai on :Oxy ha cc cht hu c :CxHyOz + O2 Enzyme CO2 + H2O + HTng hp t bo mi :CxHyOz + O2 + NH3 Enz ymeT bo vi khun (C5H7O2N) + CO2 + H2O - HPhn hy ni bo :C5H7O2N + O2 Enz yme 5CO2 + 2H2O + NH3 t H 2.3.3.2. Phng php x l k kh 2.3.3.2. Phng php x l k khS dng vi sinh vt k kh, hot ng trong iu kin ym kh khng hoc c lng O2 ha 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 :a. Thy phn : Trong giai on ny, di tc dng ca enzyme do vi khun tit ra, ccphccht vcccht khngtan(nhpolysaccharide, protein, lipid) chuyn ha thnh cc phc cht n gin hn hoc cht ha tan (nh ng, cc acid amin, acid bo). b. Acid ha : Trong giai on ny, vi khun ln men chuyn ha cc cht ha tan thnh cht n gin nh acid bo d bay hi, ru, acid lactic, methanol, CO2, H2, NH3, H2S v sinh khi mi. GVHD: ThS. Nguyn Xun Hon Trang 10 n mn hc X L Nc Thi Lp HMT1c. Acetic ha : Vi khun acetic chuyn ha cc sn phm ca giai on acid ha thnh acetat, H2, CO2 v sinh khi mi.d. 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, CO2v sinh khi mi.2.3.3.3. Cc h thng x l nhn to bng phng php sinh hc 2.3.3.3. Cc h thng x l nhn to bng phng php sinh hca. X l theo phng php hiu khX l nc thi theo phng php hiu kh nhn to da trn nhu cu oxy cn cung cp cho vi sinh vt hiu kh c trong nc thi hot ng v pht trin. Cc vi sinhvthiukh sdngcccht huc, ccngunNvPcngvi 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 CO2 v nc. C hai qu trnh dinh dng v h hp ca vi sinh vt u cn oxy. p ng nhu cu oxy ha tan trong nc, ngi ta thng s dng h thng sc kh b mt bng cch khuy o hoc bng h thng kh nn. Qu trnh x l hiu kh vi vi sinh vt sinh trng dng l lng (bn hot tnh)Qu trnh ny s dng bn hot tnh dng l lng x l cc cht hu c ha tan hoc cc cht hu c dng l lng. Sau mt thi gian thch nghi, cc t bo vi khun bt u tng trng v pht trin. Cc ht l lng trong nc thi c cc t bo vi sinh vt bm ln v pht trin thnh cc bng cn c hot tnh phn hy cc cht hu c. Cc ht bng cn dn dn ln ln do c cung cp oxy v hp th cc cht hu c lm cht dinh dng sinh trng v pht trin.Bn hot tnh l tp hp cc vi sinh vt khc nhau, ch yu l vi khun, bn cnh cn c nm men, nm mc, x khun, nguyn sinh ng vt, giun, sn, kt thnh dng bng vi trung tm l cc ht l lng trong nc. Trong bn hot tnh ta thy c loi Zoogelea trong khi nhy. Chng c kh nng sinh ra mt bao nhy xung quanh t bo, bao nhy ny l mt polymer sinh hc vi thnh phn l polysaccharide c tc dng kt cc t bo vi khun li to thnh bng.GVHD: ThS. Nguyn Xun Hon Trang 11 n mn hc X L Nc Thi Lp HMT1Mt s cng trnh hiu kh ph bin xy dng trn c s x l sinh hc bng bn hot tnh :- B aeroten thng thng i hi ch dng chy nt (plug-flow), khi chiu di b rt ln so vi chiu rng. Trong b, nc thi vo c th phn b nhiu im theo chiu di, bn hot tnh tun hon a vo u b. Tc sc kh gim dn theo chiu di b. Qu trnh phn hy ni bo xy ra cui b. - B aeroten xo trn hon toni hi chn hnh dng b, trang thit b sc kh thch hp. Thit b sc kh c kh (motour v cnh khuy) hoc thit b khuch tn kh thng c s dng. B ny thng c dng trn hoc vung, hm lng bn hot tnh v nhu cu oxy ng nht trong ton b th tch b. - B aeroten m rngHn ch lng bn d sinh ra, khi tc sinh trng thp, sn lng bn thp v cht lng nc ra cao hn. Thi gian lu bn cao hn so vi cc b khc (20-30 ngy).- Mng oxy ha L mng dn dng vng c sc kh to dng chy trong mng c vn tc xo trn bn hot tnh. Vn tc trong mng thng c thit k ln hn 3m/s trnh lng cn. Mng oxy ha c th kt hp qu trnh x l N.- B hot ng gin on (SBR)B hot ng gin on l h thng x l nc thi vi bn hot tnh theo kiu lm y v x cn. Qu trnh xy ra trong b SBR tng t nh trong b bn hot tnh hot ng lin tc, ch c iu tt c qu trnh xy ra trong cng mt b v c thc hin ln lt theo cc bc: (1) lm y, (2) phn ng, (3) lng, (4) x cn, (5) ngng. Qu trnh x l hiu kh vi vi sinh vt sinh trng dng dnh bmKhi dng nc thi i qua nhng lp vt liu rn lm gi , cc vi sinh vt s bm dnh ln b mt. Trong s cc vi sinh vt ny c loi sinh ra cc polysaccaride GVHD: ThS. Nguyn Xun Hon Trang 12 n mn hc X L Nc Thi Lp HMT1c tnh cht nh l mt polymer sinh hc c kh nng kt dnh to thnh mng. Mng ny c dy thm vi sinh khi ca vi sinh vt dnh bm hay c nh trn mng. Mng c to thnh t hng triu n hng t t bo vi khun, vi mt vi sinh vt rt cao. Mng c kh nng oxy ha cc hp cht hu c, trong do t tip xc vi c cht v t nhn c O2 s chuyn sang phn hy k kh, sn phm ca bin i k kh l cc acid hu c, cc alcol,Cc cht ny cha kp khuch tn ra ngoi b cc vi sinh vt khc s dng. Kt qu l lp sinh khi ngoi pht trin lin tc nhng lp bn trong li b phn hy hp th cc cht bn l lng c trong nc khi chy qua hoc tip xc vi mng.b. X l theo phng php k khQu trnh x l k kh vi vi sinh vt sinh trng dng l lng- B x l bng lp bn k kh vi dng nc i t di ln (UASB)V cu trc : 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 trong nc thi. Bn trong b UASB c cc tm chn c kh nng tch bn b li ko theo nc u ra.V c im : C ba qu trnhphn 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. GVHD: ThS. Nguyn Xun Hon Trang 13 n mn hc X L Nc Thi Lp HMT1Hnh 2.2: B UASB- B phn ng ym kh tip xcHn hp bn v nc thi c khuy trn hon ton trong b kn, sau c a sang b lng tch ring bn v nc. Bn tun hon tr li b k kh, lng bn d thi b thng rt t do tc sinh trng ca vi sinh vt kh chm. B phn ng tip xc thc s l mt b biogas ci tin vi cnh khuy to iu kin cho vi sinh vt tip xc vi cc cht nhim trong nc thi. Qu trnh x l k kh vi vi sinh vt sinh trng dng dnh bm- B lc k kh B lc k kh l mt b cha vt liu tip xc x l cht hu c cha nhiu cacbon trong nc thi. Nc thi c dn vo b t di ln hoc t trn xung, tip xc vi lp vt liu c cc vi sinh vt k kh sinh trng v pht trin. - B phn ng c dng nc i qua lp cn l lng v lc tip qua lp vt liu lc c nh.L dng kt hp gia qu trnh x l k kh l lng v dnh bm.2.3.3.4 2.3.3.4. Cc h thng x l t nhin bng phng php sinh hc . Cc h thng x l t nhin bng phng php sinh hca. H sinh hcNgi ta c th ng dng cc quy trnh t nhin trong cc ao, h x l nc thi. Trong cc h, hot ng ca vi sinh vt hiu kh, k kh, qu trnh cng sinh ca vi khun v to l cc qu trnh sinh hc ch o. Cc qu trnh l hc, ha hc bao gm cc hin tng pha long, lng, hp ph, kt ta, cc phn ng ha hc cng din ra ti y. Vic s dng ao h x l nc thi c u im l t tn vn u t cho qu trnh xy dng, n gin trong vn hnh v bo tr. Tuy nhin, do cc c ch x l din ra vi tc t nhin (chm) do i hi din tch t rt ln. H sinh hc ch thch hp vi nc thi c mc nhim thp. Hiu qu x GVHD: ThS. Nguyn Xun Hon Trang 14 n mn hc X L Nc Thi Lp HMT1l ph thuc s pht trin ca vi khun hiu kh, k kh, ty nghi, cng vi s pht trin ca cc loi vi nm, ru, to v mt s loi ng vt khc nhau. H h sinh hc c th phn loi nh sau: (1) H hiu kh (Aerobic Pond); (2)H ty nghi (Facultative Pond); (3) H k kh (Anaerobic Pond); (4) H x l b sung. H hiu kh (Aerobic Pond) H lm thong t nhinOxy c cung cp cho qu trnh oxy ha cht hu c ch yu do s khuch tn khng kh qua mt nc v qu trnh quang hp ca cc thc vt nc (rong, to,). Chiu su ca h phi b (thng ly khong 30-40 cm) m bo cho iu kin hiu kh c th duy tr ti y h. Trong h, nc thi c x l bi qu trnh cng sinh gia to v vi khun, cc ng vt bc cao hn nh nguyn sinh ng vt cng xut hin trong h v nhim v ca chng l lm sch nc thi (n cc vi khun). Cc nhm vi khun, to hay nguyn sinh ng vt hin din trong h ty thuc vo cc yu t nh lu lng np cht hu c, khuy trn, pH, dng cht, nh sng v nhit .Hiu sut chuyn ha BOD5 ca h rt cao, c th ln n 95%. Tuy nhin, ch c BOD5 dng ha tan mi b loi khi nc thi u vo, v trong nc thi u ra cha nhiu t bo to v vi khun, do nu phn tch tng BOD5 c th s ln hn c tng BOD5 ca nc thi u vo. Nhiu thng s khng th khng ch c nn hinnayngi tathngthit ktheolulngnpt tccmhnhth nghim. Viciuchnhlulngnpphnnhlngoxycthtct quang hp v trao i kh qua b mt tip xc nc, khng kh.Do su nh, thi gian lu nc di nn din tch ca h ln. V th h ch thch hp khi kt hp vic x l nc thi vi nui trng thy sn cho mc ch chn nui v cng nghip. H hiu khlm thong nhn toNgun oxy cung cp cho qu trnh sinh hc t cc thit b nh bm kh nn hay my khuy c hc. V c tip kh nhn to nn chiu su ca h c th t 2 - GVHD: ThS. Nguyn Xun Hon Trang 15 n mn hc X L Nc Thi Lp HMT14,5 m. Sc cha tiu chun khong 400 kg/(ha.ngy). Thi gian lu nc trong h 1-3 ngy.H hiu kh lm thong nhn to do c chiu su h ln, mt khc vic lm thong cng kh m bo ton phn v th mt phn ln ca h lm vic nh h hiu-k kh, ngha l phn trn hiu kh, phn di k kh. H ty nghi ( Facultative Pond ) Vic x l nc thi tt l do hot ng ca cc vi sinh vt hiu kh, k kh v ty nghi. T trn xung y h c 3 khu vc chnh.- Khu vc th nht (hay l khu vc hiu kh) c c trng bi h cng sinh gia vi khun v to. Ngun oxy c cung cp bi oxy kh tri thng qua qu trnh trao i t nhin qua b mt h, v oxy c to ra qua qu trnh quang hp ca to. Oxy c vi khun s dng phn hy cc cht hu c to nn cc dng cht v CO2, to s dng cc sn phm ny quang hp.- Khu vc trung gian (hay l khu vc k kh khng bt buc) c trng bi cc hot ng ca cc vi khun k kh khng bt buc.- Khu vc th ba (hay l khu vc k kh) c trng bi cc hot ng ca cc vi khun k kh phn hy cc cht hu c lng ng di y b.Hnh 2.3: H ty nghi H k kh ( Anaerobic Pond ) GVHD: ThS. Nguyn Xun Hon Trang 16 n mn hc X L Nc Thi Lp HMT1H k kh c s dng x l nc thi c hm lng cht rn cao. Thng thng y l mt ao su (c th n 9,1 m) vi cc ng dn nc thi u vo v u ra c b tr mt cch hp l. iu kin k kh c duy tr sut chiu su ca b. Vic n nh nc thi c tin hnh thng qua qu trnh kt ta, phn hy k kh ca vi sinh vt. Hiu qu kh BOD5 thng mc 70% v c th ln n 85% khi cc iu kin mi trng t ti u. H x l b sung C th p dng sau qu trnh x l sinh hc (aerotank, b lc sinh hc hoc sau h sinh hc hiu kh, ty nghi,) t cht lng nc ra cao hn, ng thi thc hin qu trnh nitrat ha. Do thiu cht dinh dng, vi sinh cn li trong h ny sng giai on h hp ni bo v amoniac chuyn ha thnh nitrat. Thi gian lu nc trong h ny khong 18 - 20 ngy. Ti trng thch hp 67 - 200kg BOD5/ha.ngy. b. Cnh ng tiDn nc thi theo h thng mng t trn cnh ng ti, dng bm v ng phn phi phun nc thi ln mt t. Mt phn nc bc hi, phn cn li thm vo t to m v cung cp mt phn cht dinh dng cho cy c sinh trng. Phng php ny ch c dng hn ch nhng ni c khi lng nc thi nh, vng t kh cn xa khu dn c, bc hi cao v t lun thiu m. cnh ng ti khng c trng rau xanh v cy thc phm v vi khun, virus gy bnh trong nc thi cha c loi b c th gy tc hi cho sc khe ca con ngi s dng cc loi rau v thc phm ny.c. X nc thi vo ao, h, sng sui Nc thi c x vo nhng ni vn chuyn v cha nc c sn trong t nhin pha long chng v tn dng kh nng t lm sch ca cc ngun. i vi nc thi chn nui heo, bin php ny thng khng c p dng v n gy mi hi thi rt nghim trng v git cht cc loi thy sinh vt sng trong nc. Mc d vy nc ta, phn ln nc thi chn nui thng x vo cc h thng sng, h gn khu vc chn nui sau khi x l bng nhng bin php th s nh hm biogas, h lng,GVHD: ThS. Nguyn Xun Hon Trang 17 n mn hc X L Nc Thi Lp HMT1Ngoi cc phng php sinh hc t nhin trn, ngi ta cn s dng cc phng php vng t ngp nc (wetland), x l bng t (land treatment), Hin nay ngi ta p dng vic s dng cc loi thc vt nc lm tng hiu qu x l t nhin ca cc ao h, c bit thch hp vi nc thi chn nui.2.3.3.5. ng dng thc vt nc x l nc thi2.3.3.5. ng dng thc vt nc x l nc thi Thc vt nc thuc loi tho mc, thn mm. Qu trnh quang hp ca cc loi thy sinh hon ton ging cc thc vt trn cn. Vt cht c trong nc s c chuyn qua h r ca thc vt nc v i ln l. L nhn nh sng mt tri tng hp thnh vt cht hu c. Cc cht hu c ny cng vi cht khc xy dng nn t bo v to ra sinh khi. Thc vt ch tiu th cc cht v c ha tan. Vi sinh vt s phn hy cc hp cht hu c v chuyn chng thnh cc cht v hp cht v c ha tan thc vt c th s dng chng tin hnh trao i cht. Qu trnh v c ha bi VSV v qu trnh hp th cc cht v c ha tan bi thc vt nc to ra hin tng gim vt cht c trong nc. V vy ngi ta ng dng thc vt nc x l nc thi. V c ha Quang hpCc cht hu cCc cht v c ha tan Sinh khi thc vtSinh khi vi sinh vtC 3 loi thc vt nc chnh:- Thc vt nc sng chm : Loithcvtncnypht trindi mtncvchphttrinc ngun nc c nh sng. Chng gy nn cc tc hi nh lm tng c ca ngun nc, ngn cn s khuch tn ca nh sng vo nc. Do cc loi thc vt nc ny khng hiu qu trong vic lm sch nc thi.- Thc vt nc sng tri ni :R ca thc vt ny khng bm vo t m l lng trn mt nc, thn v l pht trin trn mt nc. N tri ni trn mt nc theo gi v dng nc. R ca chng to iu kin cho vi khun bm vo phn hy nc thi.GVHD: ThS. Nguyn Xun Hon Trang 18 n mn hc X L Nc Thi Lp HMT1- Thc vt sng na chm na ni :Loi thc vt ny c r bm vo t nhng thn v l pht trin trn mt nc. Loi ny thng sng nhng ni c ch thy triu n nh. Mt s thc vt nc ph bin (Chongrak Polprasert, 1997)Loi Tn thng thng Tn khoa hcThc vt nc sng chmHydrilla Hydrilla verticillataWater milfoil Myriophyllum spicatumThc vt nc sng niLc bnh Eichhornia crassipesBo tm Wolfia arrhigaBo tai tng Pistia stratiotesThc vt nc sng na chm na niCattails(c ui mo) Typha sppBulrush(c li bc) Scirpus sppReed(lau sy) Phragmites communis2.3.3.6. ng dng lc bnh x l nc thi2.3.3.6. ng dng lc bnh x l nc thi Lc bnh c tn khoa hc l Eichhoria crassipes. nc ta lc bnh cn c tn l bo Ty, bo Nht Bn.Hnh 2.4: Hnh dng ca cy lc bnhLc bnh l cy thn tho, tri ni trn mt nc. Thn gm mt ci trc mang nhiu lng ngn v nhng t mang r v l.R si, c nh, khng phn nhnh, mc thnh chm di, chim 20 50% trng lng ca cy ty theo mi trng sng nhiu hay t cht dinh dng.GVHD: ThS. Nguyn Xun Hon Trang 19 n mn hc X L Nc Thi Lp HMT1L mc theo dng hoa th,cung phng ln thnh phao ni. Cy con phao ngn v phng to, cy gi cc phao ko di c th ti 30 cm. Tnh ni ca lc bnh l do t l cao ca kh trong cung l (chim 70% th tch).Hoa khng u, mu xanh nht hoc tm. i v cnh hoa cng mu dnh lin vi nhau gc, cnh hoa trn c m vng.Lc bnh sinh trng v pht trin nhit 10oC 40oC nhng mnh nht nhit 20oC 30oC, v vy nc ta lc bnh sng quanh nm.Vai tr ca cc b phn ca thc vt nc trong h thng x l (Chongrak Polprasert, 1997)Phn c th Nhim vR v/hoc thnL gi bm cho vi khun pht trinLc v hp ph cht rnThn v/hoc lmt nc hoc pha trn mt ncHp th nh sng mt tri do ngn cn s pht trin ca toLm gim nh hng ca gi ln h x lLm gim s trao i gia nc v kh quynChuyn oxy t l xung rH thng x l nc thi bng h lc bnh c th xem nh l mt b lc sinh hc nh git, vn tc thp c dng chy theo chiu ngang. C ch loi cht nhim ca h thng ch yu l lng v phn hy sinh hc, b r ca chng c tc dng nh mt b lc c hc v to gi bm cho vi sinh vt. Oxy dng oxy ha cht hu c trong h c cung cp bi s khuch tn ca khng kh, s quang hp ca to v gii phng t r ca lc bnh thng qua lp biofilm. Hai qu trnh u tin chuyn i oxy trc tip bn trong nc, trong khi qu trnh th ba oxy c gii phng thng qua lp biofilm.S khuch tn ca khng kh lin quan n hiu qu ca qu trnh di chuyn oxy qua li. Oxy di chuyn qua b mt ca h khong 0.5-1.5g/m3.ngy (Imhoff et al 1971). Trong h lc bnh, s di chuyn ny km hn do lc bnh che ph mt h v s chuyn ng khng u ca gi.GVHD: ThS. Nguyn Xun Hon Trang 20 n mn hc X L Nc Thi Lp HMT1Mt khc to khng tham gia qu trnh oxy ha khi lc bnh che ph b mt nn oxy c c do s quang hp ca to gim ng k(Gee&Jensen, 1980, trch dn bi R. Sooknah, 1999). Ngun oxy ch yu c gii phng t r lc bnh.Oxy t r lc bnh di chuyn vo nc thng qua lp biofilm. Gi thuyt v cutrccalpbiofilmcngh bi Timberlake(Timberlakeet al, 1988). Theo tc gi, lp biofilm c th c 4 vng cho vi khun hot ng, lp nitrat ha nm gn vng cung cp, lp ln men ym kh nm gn b mt cht lng v 2 lp trung gian l kh nitrat v s oxy ha hectotrophic. Do nng oxy trong nc gim theo chiu su. C ch loi cht hu c BOD5 Trong cc h x l, cc cht rn lng c s lng xung y di tc dng ca trng lc v sau b phn hy bi cc vi sinh vt k kh. Cc cht rn l lng hoc hu c ha tan c loi i bi hot ng ca cc vi sinh vt nm l lng trong nc bm vo thn v r ca lc bnh. Vai tr chnh ca vic loi cht hu c l do hot ng ca cc vi sinh vt, vic hp thu trc tip do lc bnh khng ng k nhng lc bnh to gi bm cho cc vi sinh vt thc hin vai tr ca mnh. C ch loi N B hp th bi lc bnh v sau khi lc bnh c thu hoch th N c loi khi h thng. S bay hi ca amoniac. Qu trnh nitrat ha v kh nitrat ha ca cc vi sinh vt.Trong qu trnh nitrat ha v kh nitrat ha gp phn ln nht. Lc bnh cung cp gi bm cho cc vi khun nitrat ha. qu trnh nitrat ha c th xy ra, hm lng DO phi mc 0,61,0 mg/L. Do su m qu trnh nitrat ha c th xy ra quan h mt thit vi lu lng np BOD v tc chuyn ha oxy vo nc. Qu trnh kh nitrat ha din ra trong iu kin thiu kh (anoxic) v qu GVHD: ThS. Nguyn Xun Hon Trang 21 n mn hc X L Nc Thi Lp HMT1trnh ny cn phi cung cp thm ngun carbon cho cc vi sinh vt tng hp cc t bo ca n v pH phi duy tr mc trung tnh. C ch loi PP trong nc thi c kh i do lc bnh hp th vo c th, b hp ph hay kt ta. Trong c ch kh P, hin tng kt ta v hp ph gp phn quan trng nht (Whigram et al, 1980 trch dn bi L Hong Vit, 2000). Tuy nhin, hiu sut ca qu trnh ny kh c th tin on c. Qu trnh hp ph v kt ta ph thuc vo cc nhn t nh l pH, kh nng oxy ha kh, hm lng st, nhm, canxi v cc thnh phn st.Cui cng, P s c loi b khi h thng qua vic : Thu hoch lc bnh. Vt bn lng y.Cng dng ca lc bnhLc bnh l mt trong cc thc vt nc c tc tng trng nhanh nht, kh nng cnh tranh dinh dng v cc yu t cn thit cho s sng ca lc bnh cao hn hn so vi cc thc vt nc khc. Trong mt thi gian ngn, lc bnh pht trin sinh khi lm kn c mt h. Ngi dn thng thu hoch lc bnh tn dng vo cc mc ch sau : Lm nguyn liu cho cc ngnh th cngHin nay Vit Nam, lc bnh ang thiu trong ngh an gi xut khu, gi lc bnh kh l 6,500-7000/kg. Lc bnh rt c gi tr kinh t. Lm thc phm cho gia sc Lm phn xanhLc bnh l mt trong nhng nguyn liu dng sn xut phn xanh rt c hiu qu v thnh phn dinh dng trong lc bnh kh cao. Dng sn xut kh sinh hc biogasGVHD: ThS. Nguyn Xun Hon Trang 22 n mn hc X L Nc Thi Lp HMT1Lc bnh c cc vi sinh vt k kh phn gii to thnh sn phm cui cng ca qu trnh phn hy l kh CH4, kh ny c th tn dng lm kh t trong vic to ra nng lng cho sinh hot hay cho cc ngnh sn xut.Hnh 2.5: H hiu kh c s dng thc vt nc l lc bnhGVHD: ThS. Nguyn Xun Hon Trang 23 n mn hc X L Nc Thi Lp HMT1CHNG 3: XUT CC PHNG N X CHNG 3: XUT CC PHNG N X L NC THI CHN NUI HEO CNG L NC THI CHN NUI HEO CNG SUT 500M SUT 500M3 3/NGY M /NGY M3.1. C s la chn phng n x l nc thi 3.1. C s la chn phng n x l nc thi xc nh c dy chuyn cng ngh x l cn phi phn tch c cc ch tiu gy nhim, cng vic ny c tnh cht rt quan trng v n quyt nh dy chuyn cng ngh v hiu sut ca qu trnh x l nc thi.Lng nc thi chn nui ch yu l t cng on tm cho heo v ra chung, v vy m thnh phn ca nc thi ch yu l ca phn v nc tiu. l l do m hm lng BOD, Nit tng v photpho tng trong nc thi cao. Cng vic loi b Nit v photpho trong nc l rt kh, thng c x l bng phng php sinh hc.Thnh phn nc thi chn nui heoc tnh Nng n vTiuchnthi ngun loi B (5945-1995)pH 7,2 5,5-9BOD5 2817 mg/L 50COD 5210 mg/L 100SS615 mg/L 100Ntng 206 mg/L 60Ptng 37 mg/L 6Coliform 5,8.109MPN/100mL-GVHD: ThS. Nguyn Xun Hon Trang 24 n mn hc X L Nc Thi Lp HMT13.2. Phn 3.2. Phng n 1 g n 1 Thuyt minh qui trnh cng nghNcthicaquali chnrcnhmloibmtphnrcckch thc ln, rc t y c thu gom v em i chn lp. Sau nc thi c a qua b lng ct. Ti y, lng ct c trong nc thi s lng xung v c em i san lp. Nc t b lng ct tip tc qua b iu ha n nh lu lng v nng . Sau , nc thi c bm n b lng t I tch mt phn cht hu c d lng. Bn thu c ti y l dng bn ti, c bm v b nn bn. Nc thi c tip tc bm qua b UASB, sau cng trnh ny nc c a qua b lc sinh GVHD: ThS. Nguyn Xun Hon Trang 25Nc thing ncng bnB lng ctB iu haB lng 1B UASBB lng 2B lc sinh hc cao tiB tip xcB nn bnNgun tip nhnSan lpMy nn bnLi chn rcNc sau tch bnChn lpngkhng ctMy thi khLm phn bn n mn hc X L Nc Thi Lp HMT1hc cao ti. Nc thu c cho chy qua b lng t 2, sau kh trng bng clo trc khi a ra ra ngun tip nhn. u im Din tch cng trnh nh. Hiu qu x l tng i cao, nc u ra t tiu chun. Khuyt im B lc sinh hc cao ti d b tt nghn theo thi gian. Tn chi ph ha cht. Chi ph vn hnh cao.3.3. Phng n 23.3. Phng n 2 GVHD: ThS. Nguyn Xun Hon Trang 26Nc thing ncng bnNgn tip nhnB lng ctB iu haB lng 1B UASBB lng 2B aerotankH sinh hcB nn bnNgun tip nhnSan lpMy nn bnLi chn rcNc sau tch bnChn lpngkhng ctLm phn bnMy thi kh n mn hc X L Nc Thi Lp HMT1 Thuyt minh qui trnh cng nghNc thi c a qua li chn rc nhm loi b mt phn rc c kch thc ln, rc t y c thu gom v em i chn lp. Sau nc thi c a vo ngn tip nhn ri qua b lng ct. Ti y, lng ct c trong nc thi s lng xung v c em i san lp. Nc t b lng ct tip tc qua b iu ha n nh lu lng v nng cc cht gy nhim. Sau , nc thi c bm n b lng t I c dng b lng ly tm tch mt phn cht hu c d lng. Bn thu c ti y c bm v b nn bn. Nc thi tip tc qua b UASB. Ti b UASB, cc vi sinh vt k kh dng l lng s phn hy cc cht hu c c trong nc thi thnh cc cht v c dng n gin v kh CO2, CH4, H2S. Trong b UASB c b phn tch 3 pha: kh , nc thi v bn. Nc thi sau khi c tch bn v kh c dn sang b Aerotank. Ti y din ra qu trnh phn hy hiu kh cc hp cht hu c. B c thi kh lin tc nhm duy tr iu kin hiu kh cho vi sinh vt pht trin. Sau nc thi c dn sang b lng II, ti y din ra qu trnh phn tch nc thi v bn hot tnh. Bn hot tnh lng xung y, nc thi pha trn c dn quah sinh hc x l tip. Nc thi sau khi qua h sinh hc t tiu chun loi B s c thi ra ngun tip nhn. u im H thng x l nc thi vn hnh tng i d dng. Nc u ra t tiu chun. Kh thi v mt kinh t. Khuyt im Tn nhiu din tch do s dng h sinh hc trong qu trnh x l. Qu trnh vn hnh cn phi theo di thng xuyn cng sc kh trong b.GVHD: ThS. Nguyn Xun Hon Trang 27 n mn hc X L Nc Thi Lp HMT1CHNG 4: TNH TON CHI TIT CC CHNG 4: TNH TON CHI TIT CC CNG TRNH N V THEO PHNG N 2 CNG TRNH N V THEO PHNG N 24.1. Li chn rc 4.1. Li chn rc4.1.1. Nhim vLi chn rc c nhim v tch cc vt th nh gi, rc, v hp, cc mu , g v cc vt khc trc khi a vo cc cng trnh x l pha sau. Li chn rc c th t c nh hoc di ng, li chn rc gip trnh cc hin tng tc nghn ng ng, mng dn v gy tt nghn bm.4.1.2. Tnh tonLu lng nc thi ra ca tri chn nui l Qt= 500(m3/ng). Thi gian tm heo trong ngy l 3 ln, mi ln l t 5h - 7h, 9h - 11h v t 16 - 18h. Thi gian nc thi ra trong mt ngy l 6 gi, vy lu lng trong 1 gi l:( )350083, 33 m / h6hQQt Chn li c nh dng lm c kch thc mt li d = 0,35mm tng ng vi ti trng LA = 700l/phut.m2, t hiu qu x l cn l lng E = 10%.Gi s li chn rc c chn theo thit k nh hnh c kch thc li B* L =0,8 x 1,2 m.Din tch b mt li:22 3* *83,33/ 1 10001,98700 / . 60hAQmh h lmALl phm ph m S li chn rc21, 982. 0,8 .1, 2A mn luoiB L m m Ti trng lm vic thc t323* *83,33/ 1 1000723 / .0,8 *1,2 *2 60 * *thhAQmh h ll phmLm m ph L B nm Tng lng SS sau khi qua lichn rc gim 10%SS cn li=615.(1 0,1)=553,5(mg/l)GVHD: ThS. Nguyn Xun Hon Trang 28 n mn hc X L Nc Thi Lp HMT14.2. Ngn tip nhn 4.2. Ngn tip nhn4.2.1. Nhim vNc thi t tri chn nui heo sau khi qua li chn s chy n ngn tip nhn. T y nc thi c a i phn phi cho cc cng trnh x l tip theo.4.2.2. Tnh tonTh tch hu ch ca ngn tip nhn c tnh theo cng thc:31. 83, 33.30. 41, 7( )60hV Q t m Vi : tl thi gian lu nc trong ngn tip nhn, t = 10 30 pht.Chn t = 30 phtKch thc ngn tip nhn:Chn chiu su hu ch h = 2 mChiu cao bo v hbv = 0,5 m Chiu cao xy dng ngn tip nhn: H = h + hbv = 2,5 (m)==> 241, 720, 85( )2VB L mh Chn B = 4 m , L = 5 mVy kch thc ngn tip nhn l: L x B x H = 5 x 4 x 2,5m.Tnh bm chm bm nc thiCng sut ca bm c tnh theo cng thc:. . . 1000.9, 81.6.83, 331, 7( )1000 1000.0,8.3600g H QN kW GVHD: ThS. Nguyn Xun Hon Trang 29Mt bng ngn tip nhn Mt ct 1 - 1 n mn hc X L Nc Thi Lp HMT1Vi:Q : lu lng nc thi (m3/s).H : chiu cao ct p ton phn, H = 6 (mH2O).: khi lng ring ca nc (kg/m3).: hiu sut bm (%).Cng sut thc t ca my bm:NTT = 1,2.N = 1,2.1,7 = 2 (kW)Chn 2 bm cng sut 2kW, 1 bm hot ng v 1 bm d phng.Bng tng hp cc thng s thit k ngn tip nhnSTT Tn thng s n v Kch thc1 Chiu di m 52 Chiu rng m 43 Chiu cao m 2,54 Thi gian lu nc pht 304.3. B lng ct 4.3. B lng ct4.3.1 Nhim vNhim v ca b lng ct l lng cc ht cn c kch thc ln nhm bo v cc thit b my mc khi b mi mn, gim s lng ng cc vt liu nng trong ng, knh, mng dnB lng ct dng tch cc hp phn khng tan v c ch yu l ct ra khi ngun nc.4.3.2. Tnh tonB lng ct ngang phi m bo vn tc chuyn ng ca nc l 0,15 m/s v 0,3 m/s v thi gian lu nc trong b l 30s t 60s (iu 6.3.20 TCXD 51 84).Chn thi gian lu ca b lng ct ngang: t = 60sCh vn tc nc trong b lng ngang: vn = 0,2 (m/s)Th tch tng cng ca b lng ct ngang383, 33.60. 1, 4( )3600sW Q t m Din tch mt ct ngang ca b lng ct ngangGVHD: ThS. Nguyn Xun Hon Trang 30 n mn hc X L Nc Thi Lp HMT1283, 330,120, 2.3600snnQF mv Chiu rng ca b lng ct ngang0,120, 40, 3nFB mH Vi H: chiucaocngtccablngct ngang0,25m-1m. (iu6.3.4 TCXD 51-84). Chn H = 0,3 m.Chia b lng ct thnh 2 n nguyn n = 2.Chiu di ca b lng ngang1, 45,83* * 2*0, 4*0, 3WL mn B H ChnL = 6mLng ct trung bnh sau mi ngy m0 3*500*0,150, 075 /1000 1000tbngaycQ qW m ngaydem Vi q0: lng ct trong 1000m3 nc thi, q0 = 0,15m3ct/ngaydemChiu cao lp ct trong b lng ct ngang trong 1 ngy m:* 0, 075*10, 016* * 6*0, 4*2c xcW th mL B n Vi tx = 1: chu k ly ct l 1 ngy mChiu cao xy dng ca b:HXD = h + hc + hbv = 0,3 + 0,016 + 0,3 = 0,62mTrong :h : chiu cao cng tc ca b lng ct; h = 0,5m.hc : chiu cao lp ct trong b; hc = 0,0125m.hbv: chiu cao bo v; hbv = 0,3 m.4.4. B iu ha 4.4. B iu ha4.4.1. Nhim vB iu ho c nhim v iu ho lu lng v nng nc thi dng vo, trnh lng cn v lm thong s b, qua oxy ho mt phn cht hu c trong nc thi. Nc thi c n nh v lu lng v nng thun li cho vic x l cc cng trnh x l sau, nht l s trnh c hin tng qu ti ca h thng x l.GVHD: ThS. Nguyn Xun Hon Trang 31 n mn hc X L Nc Thi Lp HMT1 m bo iu ho nng , lu lng v trnh lng cn, b c b tr h thng thi kh lm vic lin tc.4.4.2. Tnh tonChn thi gian lu nc ca b iu ho t = 6h (quy phm 6 - 12h).Th tch cn thit ca b:V = htbQ . t = 20,83.8 = 166,67 (m3)Chn chiu cao hu ch ca b iu l H = 4m.Chiu cao bo v l Hbv = 0,3m. Chiu cao xy dng b iu ha l 4,3m.Din tch b: 2166, 6741, 67( )4VF mH Chn chiu rng b l 6m, chiu di b l 7m.Vy kch thc b iu ha l L x B x H = 7 x 6 x 4,3 (m).Tnh ton h thng sc khChn khuy trn b iu ha bng h thng thi kh. Lng kh nn cn cho thit b khuy trn:qkh = R * Vdh = 0,012 m3/m3.pht * 208,42m3 = 2,5m3/pht = 2500 l/pht.Trong :R: tc kh nn, R = 10 15 l/m3.pht.Chn r = 12l/m3.pht = 0,012 m3/m3.phtVdh: th tch ca b iu hoCc thng s cho thit b khuch tn khLoi khuch tn khCch b trLu lng kh(l/pht.ci)Hiu sut chuyn ho oxyTiu chun su 4.6m, %a s - liChp s - liBn s - ling plastic xp cng b tr:Dng liHai phatheochiudi( dng chy xon hai bn)11 9614 7157 14268 11385 31125 4027 3926 3328 3217 28GVHD: ThS. Nguyn Xun Hon Trang 32 n mn hc X L Nc Thi Lp HMT1Mt pha theo chiu di(dng chy xon mt bn)ng plastic xp mm b tr:Dng liMt pha theo chiu ding khoan l b tr:Dng liMt pha theo chiu di57 34028 19857 19828 11357 17013 2525 3619 3722 2915 19Chn khuch tn kh bng a s b tr dng li. Vy s a khuch tn l:n =25003080kkqr (a)Trong : r: lu lng kh, chn r = 80 l/pht. a.Cc a c b tr dng li u khp y b. Phn phi a thnh 6 hng theo chiu di, mi hng 5 a.Chn ng ng dn kh:Vi lu lng kh qkk = 2,5 m3/pht = 0,042 m3/s v chn vn tc kh trong ng vkk= 10 m/s (v = 10 15 m/s) c th chn ng knh ng chnh :4 4.0, 0420, 07( ). .10kkqD mv Chn ng chnh c ng knh 75mm.i vi ng nhnh c lu lng 33 30, 042 /7.10 /6nm sq m s v chn vn tc trong ng nhnh l 10 m/s ng knh ng nhnh l:34 4.7.100, 03( ). .10kknqD mv Chn ng chnh c ng knh 32 mm.p lc v cng sut ca h thng nn kh p lc cn thit cho h thng nn kh xc nh theo cng thc:Htc = hd + hc + hf + HTrong :hd: tn tht p lc do ma st dc theo chiu di trn ng ng dnGVHD: ThS. Nguyn Xun Hon Trang 33 n mn hc X L Nc Thi Lp HMT1hc: tn tht p lc cc b, mhf: tn tht qua thit b phn phi, mH: chiu cao hu ch ca b iu ho, H = 4 mTng tn tht hdv hcthng khng vt qu 0,4m, tn tht hfkhng vt qu 0,5m, do p lc cn thit l:Htc = 0,4 + 0,5 + 4 = 4,9 mH2O = 0,49 at Cng sut my thi kh tnh theo cng thc sau:0,28321. .129, 7. .G RT PPn P 1 _ 1 1 , ]Trong :+ P: Cng sut yu cu ca my (KW)+ G: trng lng dng kh(Kg/s)G = qk . kh = 0,042.1,29 = 0,054 (Kg/s)+R: hng s kh. R = 8,314 (KJ/K.mol.oK )+ T: nhit tuyt i ca khng kh u vo:T1= 273 + 25 = 298 oK+ P1 : p lc tuyt i ca khng kh u vo, P1 = 1at+ P2: p lc tuyt i ca khng kh u ra, P2 =Htc + 1at = 1,49 at+1 1, 395 10, 2831, 395knk ( k = 1,395 i vi khng kh).+ 29,7: h s chuyn i.+: hiu sut ca my nn kh, = 0,7 0,9, chn = 0,8.0,2830, 054.8, 314.298 1, 491 2, 4( )29, 7.0, 283.0, 8 1P KW 1 _ 1 , 1 ]Cng sut ca my thi kh l 2,4KW.Tnh ton cc ng dn nc vo v ra khi b iu ho:Nc thi c bm t ngn tip nhn vo b iu ho, chn vn tc nc vo b l 0,7 m/s, lu lng nc thi 55,56m3/h, ng knh ng vo l:4 4.55, 560,168( ). .3600 .0, 7.3600vQD mv Chn ng nha PVC c ng knh 160GVHD: ThS. Nguyn Xun Hon Trang 34 n mn hc X L Nc Thi Lp HMT1Chn vn tc nc ra khi b l 1m/s, ng knh ng dn nc ra:4.20, 830, 086( ).1.3600rD m Chn ng nha PVC c ng knh 90.Tnh bm bm nc thiCng sut ca bm c tnh theo cng thc:. . . 1000.9, 81.8.20,830, 57( )1000 1000.0,8.3600g H QN kW Vi:Q : lu lng nc thi (m3/s).H : chiu cao ct p ton phn, H = 8 (mH2O). : khi lng ring ca nc (kg/m3).: hiu sut bm (%). Chn = 0,8.Cng sut thc t ca my bm:NTT = 1,2.N = 1,2.0,57 = 0,7 (kW)Chn 2 bm cng sut 0,7 kW, 1 bm hot ng v 1 bm d phngTng hp tnh ton b iu hoThng s Gi trChiu di, L(m) 7Chiu rng, B(m) 6GVHD: ThS. Nguyn Xun Hon Trang 35 n mn hc X L Nc Thi Lp HMT1Chiu cao, H(m) 4,3S a khuych tn kh, n(a) 30ng knh ng dn kh chnh, D(mm) 75ng knh ng nhnh dn kh, dn(mm) 32ng knh ng dn nc vo b (mm) 160ng knh ng dn nc ra khi b (mm) 90Cng sut my nn kh, N(kW) 2,44.5. B lng t I 4.5. B lng t I4.5.1. Nhim vNhim v ca b lng t I l loi b cc tp cht l lng cn li trong nc thi sau khi qua cc cng trnh x l trc . y cc cht l lng c t trng ln hn t trng ca nc s lng xung y.4.5.2. Tnh tonGi s sau li chn rc, b lng ct, b iu ha, hm lng cht rn gim khong 25%. Nng SS vo b lng I l 461 mg/l.Hiu qu kh SS ca b lng I t 60%. Vy hm lng cn l lng ra khi b lng I l 184 mg/l.Chn b lng t I c dng hnh trn trn mt bng, nc thi vo t tm v thu nc theo chu vi b (b lng ly tm).Cc thng s c bn thit k cho b lng t IThng s Gi trTrong khong c trngThi gian lu nc, giTi trng b mt, m3/m2.ngy Lu lng trung bnh Lu lng cao im1.5 2.532 4880 1202.0102GVHD: ThS. Nguyn Xun Hon Trang 36 n mn hc X L Nc Thi Lp HMT1Ti trng mng trn, m3/m .ngyng trung tm ng knh Chiu caoChiu su H ca b lng, mng knh D ca b lng, m dc y b, mm/mTc thanh gt bn, vng/pht125 - 50015 20% D55 65% H3.0 4.63.0 6062 1670.02 0.052483.612 45830.03Din tch b mt ca b lng ly tm trn mt bng c tnh theo cng thc:250015, 625( )32AQA mL Trong :Q:lu lng nc thi (m3/ng).LA: ti trng b mt, chn LA = 32 (m3/m2.ngy)ng knh b lng:4 4. .15, 625 4, 46( ) D A m ng knh ng trung tm:d = 20%D = 20%.4,46 = 0,9 (m)Chn chiu su hu ch ca b lng H=3m, chiu cao lp bn lng hb=0,7m, chiu cao lp trung ho hth= 0,2m, chiu cao bo v hbv= 0,3m. Vy chiu cao tng cng ca b lng t I l:Htc = H + hb + hth + hbv = 3 + 0,7 + 0,2 + 0,3 =4,2 (m)Chiu cao ng trung tm:h = 60%H = 60%.3= 1,8 (m)Kim tra thi gian lu nc ca b lng:Th tch b lng:2 2 2 2 3( ). (4, 46 0, 9 ).3 45( )4 4W D d H m Thi gian lu nc:45.242,16( ) (1, 5 2, 5)500Wt hQ tho mnGVHD: ThS. Nguyn Xun Hon Trang 37 n mn hc X L Nc Thi Lp HMT1Ti trng b mt:Ls = QD 50035, 68.4, 46 (m3/m.ngy)Ls < 500m3/m.ngy tho mnGi s hiu qu x l cn l lng t 60% ti trng 32m3/m2.ngy. Lng bn ti sinh ra mi ngy l:Mti = 461gSS/m3.500m3/ngy.0,6/1000g/kg = 138,3 (kgSS/ngy)Gi s nc thi c hm lng cn 5% ( m 95%), t s VSS : SS = 0,8 v khi lng ring ca bn ti = 1,053kg/l. Vy lu lng bn ti cn phi x l l:Qti = 138, 3 / 1.0, 05.1, 053 / 1000kg ngaykg l 2,63 (m3/ngy)Lng bn ti c kh nng phn hu sinh hc:Mti (VSS)= 138,3 kgSS/ngy.0,8 = 110,64 (VSS/ ngy)Mng thu ncMng thu nc t vng trn, c ng knh bng 0,8 ng knh b:Dm = 0,8.D = 0,8.4,46 = 3,57 (m)Chiu di mng thu nc:Lm = Dm = .3,57 = 11,2 (m)Chiu cao mng hm = 0,5mGVHD: ThS. Nguyn Xun Hon Trang 38 n mn hc X L Nc Thi Lp HMT1Mng b tng ct thp dy 100mm, c lp thm mng rng ca thp tm khng g c dng ch V, gc 900C.Tnh bm bn n b nn bn: bm 10 pht/ngy N = 1008.9, 81.10.0, 0040, 5( )1000 1000.0, 8gHQkW Trong : Q : lu lng bn bm n b nn bn (m3/s).H : chiu cao ct p ton phn. H = 10 (mH2O).: khi lng ring ca bn (kg/m3).= 1008 kg/m3. : hiu sut bm (%). Chn = 0,8.Cng sut thc t ca my bm:NTT = 1,2.N = 1,2.0,5 = 0,6 (kW)Chn 2 bm cng sut 0,6 kW hot ng lun phin nhau bm bn n b nn bn.Tnh bm t b lng I sang b UASBCng sut ca bm c tnh theo cng thc:N = 1008.9, 81.6.20, 830, 43( )1000 1000.0, 8.3600gHQkW Vi:Q : lu lng nc thi (m3/s).H : chiu cao ct p ton phn, H = 6 (mH2O).: khi lng ring ca nc (kg/m3).: hiu sut bm (%). Chn = 0,8.Cng sut thc t ca my bm:GVHD: ThS. Nguyn Xun Hon Trang 39 n mn hc X L Nc Thi Lp HMT1( ) 1, 2 1, 2 0, 43 0, 52TTN N kW Chn 2 bm cng sut 0,52 kW, 1 bm hot ng v 1 bm d phng.Tng hp tnh ton b lng t IThng s Gi trng knh b lng, D(m) 4,46Chiu cao b lng, H(m) 4,2ng knh ng trung tm, d(m) 0,9Chiu cao ng trung tm, h(m) 1,8Kch thc mngng knh mng thu nc, m 3,57Chiu di mng thu nc, m 11,2Chiu cao mng thu nc, m 0,5Lng bn ti sinh ra mi ngy, Mti(kgSS/ngy) 138,3Lu lng bn ti cn x l, Qti(m3/ngy) 2,634.6. B UASB 4.6. B UASB4.6.1. Nhim vLm gim ng k hm lng COD, BOD trong nc thi bng cch s dng lp cn l lng (c cha rt nhiu vi sinh vt ym kh) trong dch ln men nh h thng nc thi chy t pha di ln. ng thi to thun li cho qu trnh x l hiu kh trong b aerotank.4.6.2. Tnh tonGi s sau cc cng trnh x l s b hiu qu x l t c:ECOD = 20%EBOD = 20%Cc thng s u vo:Lu lng Q=500 m3/ng.BOD5 = 2254 mg/lCOD = 4168 mg/lSS = 184 mg/lCc thng s u ra:BOD5 = 451 mg/l(EBOD = 80%)COD = 834 mg/l(ECOD = 80%)SS= 147 mg/l(ESS = 20%)Dung tch phn x l k kh cn thit:GVHD: ThS. Nguyn Xun Hon Trang 40 n mn hc X L Nc Thi Lp HMT1. 500.4168260, 58.1000CODQCVL (m3)Trong :C: Hm lng COD u vo (mg/l).LCOD: Ti trng th tch. LCOD = 8kgCOD/m3.ngy. (Bng 10 10, XLNT th v cng nghip, Lm Minh Trit).Din tch b mt b UASB:250041, 66( )12AQF mL Vi:LA: Ti trng b mt phn lng, L = 12 m3/m2.ngy. (Bng 10 9, XLNT th v cng nghip , Lm Minh Trit).Chia b thnh 2 n nguyn hnh vung, vy cnh mi n nguyn l:41, 664, 56( )2FW mn Chiu cao phn x l k kh:1260.56, 25( )41, 66VH mF Tng chiu cao ca b l:H = H1 + H2 + H3Trong : H1: chiu cao phn x l k kh.H2: chiu cao phn lng, chn H2 = 1,5m.H3: chiu cao bo v, H3 = 0,3m. Chiu cao b: H = 6,25 + 1,5 + 0,3 = 8,05(m)Chn H = 8m.B tr mi n nguyn 2 phu thu kh. Mi phu c chiu cao 1,5m. y phu thu kh c chiu di bng cnh n nguyn: l = W = 4,56m v chiu rng W = 1,9m.Vy phn din tch b mt khe h gia cc phu thu kh l:4, 56.4, 56 2.4, 56.1, 9.100 .100 16, 67%4, 56.4, 56pkhA AAA A

Gi tr ny nm trong khong Akh/A = 15 20%GVHD: ThS. Nguyn Xun Hon Trang 41 n mn hc X L Nc Thi Lp HMT1Trong :A: Din tch b mt bAkh: Din tch khe h gia cc phu thu khAp: Din tch y phu thu khTnh h thng phn phi nc:B tr mi n nguyn 10 ng phn phi nc vo, din tch trung bnh cho 1 u phn phi l:4, 56.4, 562,110na m2/u [2 5 m2/u]Lng bn nui cy ban u cho vo b ( TS = 5% ). 30.260, 5156, 30, 05.1000SSbC VMTS (tn)Trong :Css: Hm lng bn trong b. Css = 30 kg/m3 (Theo X l nc thi th v cng nghip, Lm Minh Trit).TS: Hm lng cht rn trong bn nui cy ban u.Hm lng COD ca nc thi sau x l k kh:CODra = (1 ECOD).CODvo = (1 0,8).4168 = 834 mg/lHm lng BOD5 ca nc thi sau x l k kh:BOD5 = (1 EBOD).BODvo = (1 0,8).2254 = 451 mg/lLng sinh khi hnh thnh mi ngy:( )01xd cY S S QPk 1 ]+Trong :Y: h s sn lng sinh t bo, Y = 0,04 g VSS/g CODkd: h s phn hy ni boc: thi gian lu bn (35 100 ngy), chn c = 90 ngyS0, S: lng COD u vo v u ra bTh tch kh metan sinh ra mi ngy CH4[ ]40159 ( ) 1, 42CH xV S S Q P 4(4168 834).500350, 84 1, 42.28, 41000CHV1 1 ]GVHD: ThS. Nguyn Xun Hon Trang 42 n mn hc X L Nc Thi Lp HMT1= 570701 (l/ngy) = 507,1(m3/ngy)Trong :4CHV: th tch kh metan sinh ra iu kin chun ( nhit 00C v p sut 1atm)Px: lng sinh khi sinh ra mi ngy (kgVS?ngy)350,84: h s chuyn i l thuyt lng kh metan sn sinh t 1kg BODL chuyn thnh kh metan v CO2 (lit CH4 / kg BODL)Lng bn d bm ra mi ngy:28, 41, 260, 75. 0, 75.30xwssPQC (m3/ngy)CSS: hm lng bn trong b (kg/m3)Lng cht rn t bn d:MSS = Qw.CSS = 1,26.30 = 37,8 (kg SS/ngy)Tnh cc ng phn phi nc vo b UASB:Vn tc nc chy trong ng chnh v = 0,8 - 2m/s, chn v = 1m/s.D = 4. .24.3600Qv =4.500.1.24.3600 = 0,086 (m) Chn ng nha PVC c ng knh90 T ng chnh chia lm 2 ng nhnh vo 2 n nguyn.Vn tc nc chy trong ng nhnh v = 0,8 - 2m/s, chn v = 1m/s.Dn = 4 / 2. .24.3600Qv = 4.500 / 2.1.24.3600 = 0,06 (m)Chn ng nha PVC c ng knh604.7. B aerotank 4.7. B aerotank4.7.1. Nhim vB aerotank c ng dng kh ph bin trong cc qu trnh x l hiu kh. Mc ch ch yu ca qu trnh ny l da vo hot ng sng v sinh sn ca vi sinh vt n nh cht hu c lm keo t cc ht cn l lng khng lng c. Ty thuc vo thnh phn nc thi c th, Nit v Photpho s c b sung gia tng kh nng phn hy ca vi sinh vt.* Cc iu kin, yu cu v cc yu t mi trng nh hng n qu trnh x l:GVHD: ThS. Nguyn Xun Hon Trang 43 n mn hc X L Nc Thi Lp HMT1- iu kin u tin: cung cp oxi v lin tc cho b sao cho lng DO ra khi b lng II khng nh hn 2 mg/l.- Nng cho php cc cht bn hu c: nu c nhiu cht bn trong nc thi s ph hy ch hot ng sng bnh thng ca vi sinh vt trong nc thi, gy "qu ti" v nu c nhiu cht c hi s gy "sc" vi sinh vt. V vy, nu nc thi c nhiu cht bn th phi pha long trc khi x l.- Lng cc nguyn t dinh dng cn thit cho qu trnh sinh ha din ra bnh thng cn nm trong gii hn cho php: N, P, K, Ca, S, P,...C th chn theo t l sau:BODton phn : N : P = 100 : 5 : 1hay COD : N : P = 150 : 5 : 14.7.2. Tnh tonCc thng s thit k nh sau:Lu lng nc thi : Q = 500 m3/ ngy m.Hm lng BOD5 trong nc thi dn vo aeroten l 451 mg/l.Hm lng BOD5 trong nc thi u ra l 90 mg/l.Chn aerotank kiu xo trn hon ton tnh ton thit k. Cc thng s c bn tnh ton : Thi gian lu bn : 15 5 cngy T s F/M : 0,2 0,6 kg/kg.ngy Ti trng th tch: 0,8 1,92 kgBOD5/m3.ngy Nng MLVSS : 2500 4000 mg/l T s tun hon bn hot tnh : Qth/Q = 0,25 1Gi s kt qu thc nghim tm c cc thng s ng hc nh sau: H s sn lng bn : Y = 0,5 mgVSS/mgBOD5. H s phn hu ni bo : kd = 0,06 ngy-1.p dng cc s liu sau dng tnh ton: T s gia lng cht rn l lng d bay hi (MLVSS) vi lng cht rn l lng (MLSS) c trong nc thi l 0,8 (MLVSS/MLSS = 0,8)GVHD: ThS. Nguyn Xun Hon Trang 44 n mn hc X L Nc Thi Lp HMT1 Nng bn hot tnh tun hon (tnh theo cht rn l lng) l 10000mg/l. Hm lng cht l lng d bay hi (MLVSS) trong hn hp bn hot tnh b aerotank X = 3800mg/l. Hm lng bn hot tnh trong b aerotank:MLSS =38004750 / .0, 8 0,8MLVSSmg l Nc thi u ra cha 60mg/l cn sinh hc, trong c 65% cn d phn hu sinh hc.Tnh kch thc b aerotankXc nh nng BOD5 ho tan trong nc u ra theo cng thc:BOD5 u ra = BOD5 ha tan i ra t b aerotank + BOD5 cha trong lng cn l lng u ra. Phn c kh nng phn hu sinh hc ca cht rn sinh hc u ra l:60.0,65mg/l = 39mg/lLng oxy cn cung cp oxy ho ht lng cn ny c tnh da vo phng trnh phn ng:C5H7O2N+5O2

5CO2 + 2H2O +NH3 + nng lng113mg 160mg1mg 1,42mg(lng oxy cung cp ny chnh l BOD20 ca phn ng)Vy BOD hon ton ca cht rn c kh nng phn hu sinh hc u ra l:39 x 1,42 (mgO2 tiu th/mg t bo b oxy ho) = 55mg/lBOD5 ca cn l lng ca nc thi sau b lng II l:BOD5 = 0,68 BOD20 = 0,68 x 55= 37 mg/lBOD5 ho tan trong nc u ra xc nh nh sau:90 mg/l = BODht5 + 37mg/l BODht5 = 53mg/lGVHD: ThS. Nguyn Xun Hon Trang 45 n mn hc X L Nc Thi Lp HMT1Xc nh hiu qu x l E:Hiu qu x l c xc nh theo phng trnh sau:E = 00.100S SSHiu qu x l tnh theo BOD5 ho tan:E = 451 53.100 88%451Hiu qu x l tnh theo BOD5 tng cng:Etc = 451 90100 80%451Th tch b aeroten c tnh theo cng thc sau:V= 3 0. . .( ) 500.10.0, 5(451 53)163.(1 . ) 3800(1 0, 06.10)cd cQ Y S SmX k + +Trong :c: thi gian lu bn, theo quy phm 5 15 ngy, chnc= 10ngyQ : lu lng trung bnh ngy, Q = 500m3/ngyY : h s sn lng bn, Y = 0,5 mgVSS/mg BOD5S0: hm lng BOD5 dn vo aerotank, S0 = 451mg/lS: hmlngBOD5hotancancthi dnrakhi aerotank,S = 53mg/l.X :nng chtl lng d bay hitronghn hp bnhot tnh, X = 3800 mg/l.kd: h s phn hu ni bo, chn kd = 0.06 ngy-1.Xc nh thi gian lu nc ca b aeroten:163.24 7,8( )500VhQ Xc nh kch thc b aeroten:Cc kch thc in hnh ca aerotank xo trn hon tonThng s Gi trChiu cao hu ch, (m) 3.0 4.6Chiu cao bo v, (m) 0.3 0.6Khong cch t y n u khuych tn kh, (m) 0.45 0.75GVHD: ThS. Nguyn Xun Hon Trang 46 n mn hc X L Nc Thi Lp HMT1T s rng : su ( W: H) 1 : 1 2.2 : 1Chn chiu cao hu ch ca b l 3,5m, chiu cao bo v l 0,5m.Vy chiu cao tng cng ca b: H = 4m.Chiu di ca aerotank l L = 9m.Chiu rng b aerotank l W = 5,2m.Kch thc b aerotank: L x W x H = 9 x 5,2 x 3,5Tnh ton lu lng bn thi b mi ngy:Gi s bn d c x b (dn n b nn bn) t ng ng dn bn tun hon v hm lng cht rn l lng d bay hi (MLVSS) trong bn u ra chim 80% hm lng cht rn l lng (MLSS). Khi lu lng bn d thi b c tnh da vo cng thc:..cw r c cV XQ X Q X +Trong : V : th tch aerotank, V = 163m3X:nngMLVSStronghnhpbnhot tnhbaerotank,X = 3800mg/l.Qw: lu lng bn thi, m3.Xr: nng MLVSS c trong bn hot tnh tun honXr= 0,8.10000 =8000 mg/lQc: lu lng nc thi ra khi b lng II, Qc = Q = 500m3/ngy.T tnh c:GVHD: ThS. Nguyn Xun Hon Trang 47 n mn hc X L Nc Thi Lp HMT1Qw= . . . (163.3800) (10.500.48)4, 7. 10.8000c c cc rV X Q XX (m3/ngy)Tnh h s tun hon T phng trnh cn bng vt cht vit cho b lng II (xem nh lng cht hu c bay hi u ra ca h thng l khng ng k), ta c:( )rr r r wX Q Q X Q X Q + + Lu lng bn tun hon:3800.500 8000.4, 74438000 3800r wrrXQ X QQX X (m3/ng)Vy, ta c: 4430, 88500rQQ Kim tra t s F/M v ti trng hu c:T s F/M xc nh theo cng thc sau:04510, 2. 3800.7, 8S FM X (ngy-1)Ti trng th tch:3 3 0. 451.500.10 .10 1, 4163S QLV ( kgBOD5/m3.ngy)C hai gi tr ny u nm trong gi tr cho php i vi aerotank xo trn hon ton:F/M = 0,2 0,6LBOD= 0,8 1,9Tnh lng oxy cn thit cn cung cp cho aerotank da trn BOD20H s to bn t vic kh BOD5Yobs= 0, 50, 3125( / )1 . 1 0, 06.10d cYmg mgk + +Lng sinh khi gia tng mi ngy tnh theo MLVSS:v o. .( )x obs raP Y Q BOD BOD

0, 3125.500.(451 53)62, 2( / )1000kgVSS ngay Lng oxy cn thit trong iu kin tiu chun:GVHD: ThS. Nguyn Xun Hon Trang 48 n mn hc X L Nc Thi Lp HMT1OCo= xoPfg kg S S Q42 , 1) / ( 10 ). .(3 = 3500.(451 53).101, 42.62, 2 204, 30, 68 (kgO2/ngy)Trong :Q : lu lng nc thi , Q = 500m3/ngy.So: BOD5 ca nc thi u voS : BOD5 ca nc thi u raf : h s chuyn i BOD5 sang BOD20, f = 0,681,42: h s chuyn i t bo sang BOD.Px: Lng sinh khi gia tng mi ngy tnh theo MLVSSLng oxy cn thit trong iu kin thc t:29, 08203, 4 262 / ng y9, 08 2St oS LCOC OC kgO C C Trong :CS : nng bo ha ca oxy trong nc nhit lm vic, CS = 9,08 mg/l.CL: lng oxy ha tan cn duy tr trong b, CL = 2mg/lTrong khng kh, oxy chim 21% th tch. Gi s rng trng lng ring ca khng kh l 1,2kg/m3. Vy lng khng kh l thuyt cho qu trnh l:226210390, 21.1, 2 0, 21.1, 2OkkMQ (m3/ngy) Gi s hiu qu vn chuyn oxy ca thut b thi kh l 8%, h s an ton khi s dng trong thit k l 1,5. Vy lng kh theo yu cu l:19481.1, 5194810, 08kQ (m3/ngy) = 0,225 (m3/giy)Tnh h thng phn phi kh Chn a phn phi kh dng a xp ng knh 170mm, din tch b mt F = 0,02m2. Lu lng ring phn phi kh ca a thi kh = 150 200 l/pht, chn= 200 l/pht.Lng a thi kh trong b aerotank:N = 3 3 310 . ( / ) 10 *194816724.60. ( / ) 24*60*200kkQ m ngayl phut (a)GVHD: ThS. Nguyn Xun Hon Trang 49 n mn hc X L Nc Thi Lp HMT1 thun li cho vic b tr ta chn s a thi kh l 60 a.Phn phi a thnh hng 10 hng theo chiu di b, mi hng 6 a.Lu lng khng kh cn kh 1kg BOD5:Lu lng kh cp cho 1m3 nc thi:C = 1948138, 9500kkQQ (m3/m3)Lu lng khng kh cn kh 1kg BOD5:53 31948197, 9( ).10 500.(451 53).10BOD kkkkoQqQ S S (m3kh/kgBOD5)Trong : Q: lu lng nc thi.Qkk : th tch khng kh.So : BOD5 trong nc thi u voS: BOD5 trong nc thi u raTnh ton my thi khp lc cn thit cho h thng ng nn kh c xc nh theo cng thc:Htc = hd + hc + hf + H = 0,4 + 0,5 + 3,5 = 4,4 (m)Trong :hd, hc:tn tht p lc dc theo chiu di ng v tn tht cc b ti cc im un , khc quanh (m), Tng tn tht hd v hc khng vt qu 0,4m.hf: tn tht qua cc a phn phi (m), gi tr ny khng vt qu 0.5m.H: chiu cao hu ch ca b aerotank, H = 3,5m.Cng sut my thi kh tnh theo cng thc sau:0,28321. .129, 7. .G RT PPn P 1 _ 1 1 , ]Trong :+ P: Cng sut yu cu ca my (KW)+ G: trng lng dng kh(Kg/s)G = Qk . kh = 0,225.1,29 = 0,29 (Kg/s)+R: hng s kh. R = 8,314 (KJ/K.mol.oK )+ T: nhit tuyt i ca khng kh u vo:GVHD: ThS. Nguyn Xun Hon Trang 50 n mn hc X L Nc Thi Lp HMT1T1= 273 + 25 = 298 oK+ P1 : p lc tuyt i ca khng kh u vo, P1 = 1at+ P2: p lc tuyt i ca khng kh u ra, P2 =Htc + 1at = 1,44 at+ 1 1, 395 10, 2831, 395knk ( k = 1,395 i vi khng kh).+ 29,7: h s chuyn i.+: hiu sut ca my nn kh,= 0,7 0,9, chn = 0,8.Vy cng sut ca my nn kh l:0,2830, 29.8, 314.298 1, 441 11, 6( )29, 7.0, 283.0, 8 1wP kW 1 _ 1 , 1 ]Chn 2 my thi kh cng sut 11,6KW, mt hot ng, mt d phng.Chn ng ng dn khng dn kh chnh:Dchnh=4.kQv =4.0, 225.14 =0,14 (m) = 140 (mm)Trong :Qkhi: lu lng kh ng chnh.v: vn tc kh trong ng chnh, v = 10 15 m/s, chn v =14m/s Chn ng thp khng g ng knh =140mm.ng dn kh nhnh:dn = vQn.4=4.0, 0225.12 =0,049 (m) = 49mm..Trong :Qn: lu lng kh trn ng nhnhQn = Qkhi/n = 0,225/10 = 0,0225 (m3/s)n : s hng phn phi a sc khv : vn tc kh, chn v =12m/s Chn ng thp khng g ng knh= 50mm.Tnh ng dn nc thi v ng dn bn tun honng dn nc thi vo:Chn vn tc nc thi chy trong ng: v = 0,7m/sng knh ng dn l:GVHD: ThS. Nguyn Xun Hon Trang 51 n mn hc X L Nc Thi Lp HMT1D = 4.. .3600.24Qv= 0,102 (m) = 102 (mm)Chn ng nha PVC ng knh ng= 110mm.ng dn nc thi ra:Chn vn tc nc thi chy trong ng v = 0,7m/sLu lng nc thi : Q + Qr = 500 + 443 = 943 (m3/ngy) ng knh ng l:D = 4.( )24.3600. .Q Qrv+=4.94324.3600.0, 7.=0,14 (m) = 140 (mm)Chn ng nha PVC c ng knh=140mm.ng dn bn tun hon:Chn vn tc bn chy trong ng: v = 1m/sLu lng tun hon : Qr = 443m3/ngng knh ng dn l:D = 4.24.3600. .Qrv=4.44324.3600.1.3,14= 0,08 (m) = 80 (mm)Chn ng nha PVC ng knh ng= 80Bng tng hp tnh ton b aerotankThng s Gi trTh tch b: di x rng x cao 9m x 5,2m x 4mLu lng bn thi Qw (m3/ngy) 4,7T s tun hon bn, 0,88Lu lng bn tun hon, Qr(m3/ngy) 443Thi gian lu nc, (h) 7,8Lng khng kh cn, Qkk(m3/ngy) 19481Lng khng kh cn kh 1kg BOD5, qkk(m3/kg BOD5)97,9S a s khuych tn kh, N (a) 70ng knh ng dn kh chnh, D(mm) 140ng knh ng dn kh nhnh, d(mm) 50GVHD: ThS. Nguyn Xun Hon Trang 52 n mn hc X L Nc Thi Lp HMT1Cng sut my cp kh, (kW) 11,64.8. B lng II 4.8. B lng II4.8.1. Nhim vNc thi sau khi qua bAerotank s c a n b lng II, b ny c nhim v lng cc bng bn hot tnh t b Aerotank a sang. Mt phn bn lng s c tun hon tr li bAerotank, phn bn d c thi ra ngoi.4.8.2. Tnh tonChn b lng t II l b lng ly tm.Cc thng s thit k c trng cho b lng t II vi bn hot tnh khuych tn bng khng kh nh sau:Ti trng b mt, m3/m2.ngyo Trung bnh : 16,3 32,6o Ln nht : 40,7 48,8Ti trng cht rn, kg/m2.ho Trung bnh : 3,9 5,9o Ln nht : 9,8Chiu cao cng tc,m : 3,7 6,1Chn ti trng b mt thch hp cho bn hot tnh ny l 20m3/m2.ngy v ti trng cht rn l 5,5kg/m2.hDin tch b mt b lng theo ti trng b mt:AL = 250025( )20AQmL Trong :Q : lu lng trung bnh ngy, m3/ngyLA: ti trng b mt, m3/m2.ngyDin tch b mt b lng tnh theo ti trng cht rn l:GVHD: ThS. Nguyn Xun Hon Trang 53 n mn hc X L Nc Thi Lp HMT1AS = 2( ) (500 443).475033, 9( )24.5, 5.1000rSQ Q MLSSmL+ + Trong :Qr: lu lng bn tun hon, m3/ngyLS: ti trng cht rn, kgSS/m2.ngyDo AL>AS,vy din tch b mt lng tnh theo ti trng b mt l din tch tnh ton.ng knh b lng:D =A .4=4.33, 9 = 6,6 (m)ng knh ng trung tm:d = 20%D = 20%.6,6 = 1,3 (m)Chn chiu cao hu ch ca b lng l hL= 3m, chiu cao lp bn lng hb= 1,5m v chiu cao bo v hbv= 0,3m. Vy chiu cao tng cng ca b lng II:Htc = hL + hb + hbv = 3 + 1,5 + 0,3 = 4,8 (m)Chiu cao ng trung tm;h = 60%hL = 60%.3,2 = 1,92 (m)Thi gian lu nc ca b lng:+ Th tch phn lng:VL = 2 2 2 2 3( ). (6, 6 1, 3 ).3 98, 65( )4 4LD d h m +Thi gian lu nc:t = 98, 65.242, 5( )500 443LrVhQ Q + +Th tch b cha bn:Vb = A.hb = 33,9.1,5 = 50,85 (m3)Thi gian lu gi bn trong b:tb = 50,85.242, 72( )(4, 7 443)bw rVhQ Q + +Ti trng b mt:LS = (500 443)46, 2.6, 5rQ QD + + (m3/m.ngy)GVHD: ThS. Nguyn Xun Hon Trang 54 n mn hc X L Nc Thi Lp HMT1Gi tr ny nm trong khong cho php LS < 500 m3/m.ngyMng thu ncMng thu nc t vng trn, c ng knh bng 0,8 ng knh b:Dm = 0,8.D = 0,8.6,5=5,2 (m)Chiu di mng thu nc:Lm = Dm = .5,2 = 16,33 (m)Chiu cao mng hm = 0,5mMng b tng ct thp dy 100mm, c lp thm mng rng ca thp tm khng g c dng ch V, gc 900C.Tnh ng dn nc thi v ng dn bn ng dn nc thi vo:Chn vn tc nc thi chy trong ng: v = 0,7m/sLu lng nc thi vo b:Qv = Q+ Qr = 500 + 443 = 943 (m3/ngy) D = 4.24.3600. .VQv=4.94324.3600.0, 7.= 0,14 (m) = 140 (mm)Chn ng nha PVC ng knh ng= 140mmng dn nc thi ra:Chn vn tc nc thi chy trong ng v = 0,7m/sLu lng nc thi : Q= 500m3/ngng knh ng l:D = 4.24.3600. .Qv=4.50024.3600.0, 7.= 0,1(m) = 100 (mm)Chn ng nha PVC c ng knh= 100mmng dn bn:Chn vn tc bn chy trong ng: v = 1m/sLu lng bn: Qb = Qr + Qw =4,7 + 443 = 447,7 (m3/ngy)GVHD: ThS. Nguyn Xun Hon Trang 55 n mn hc X L Nc Thi Lp HMT1ng knh ng dn l:D = 4.24.3600. .bQv=4.447, 724.3600.1.= 0,08 (m) = 80 (mm)Chn ng nha PVC ng knh ng= 80mm.Tnh bm bn tun hon N = 1008.9, 81.10.4430, 63( )1000 1000.0,8.24.3600gHQkW Vi:Q : lu lng bn tun hon (m3/s).H : chiu cao ct p ton phn. H = 10 (mH2O).: khi lng ring ca bn, = 1008 (kg/m3). : hiu sut bm (%).Cng sut thc t ca my bm:NTT = 1,2.N = 1,2.0,63 = 0,76(kW)Tnh bm bn n b nn bn Thi gian bm 15 pht/ngy.N = 1008.9, 81.10.0, 0050, 65( )1000 1000.0, 8gHQkW Vi:Q : lu lng bn x ra (m3/s).H : chiu cao ct p ton phn. H = 10 (mH2O).: khi lng ring ca bn, = 1008 (kg/m3). : hiu sut bm (%).Cng sut thc t ca my bm:NTT = 1,2.N = 1,2.0,65 = 0,78 (kW)Chn 2 bm cng sut 0,78 kW hot ng lun phin nhau .Tng hp thit k b lng t IIGVHD: ThS. Nguyn Xun Hon Trang 56 n mn hc X L Nc Thi Lp HMT1Thng s Gi trng knh b lng , D(m) 6,5Chiu cao b lng, H(m) 4,8ng knh ng trung tm, d(m) 1,3Chiu cao ng trung tm, h(m) 1,92Thi gian lu nc, t(h) 2,5Thi gian lu bn, tb(h) 2,72ng knh ng dn nc thi vo (mm) 140ng knh ng dn nc thi ra (mm) 100ng knh ng dn bn (mm) 804.9. B nn bn 4.9. B nn bn4.9.1. Nhim vCn ti t b lng t I v bn hot tnh t b lng II c m tng i cao (92 96% i vi cn ti v 99,2 99,7% i vi bn hot tnh) nn cn phi gim m v th tch trc khi a vo cc cng trnh pha sau. Mt phn ln bn t b lng II c dn tr li aerotank (loi bn ny c gi l bn hot tnh tun hon), phn bn cn li c gi l bn hot tnh d c dn vo b nn bn. Nhim v ca b nn bn l lm gim m ca bn hot tnh d bng cch lng (nn) c hc t m thch hp (95 97%) phc v cho cc qu trnh x l bn pha sau.B nn bn tng i ging b lng ly tm. Ti y bn c tch nc gim th tch. Bn long (hn hp bn - nc) c a vo ng trung tm tm b. Di tc dng ca trng lc bn s lng v kt cht li. Sau khi nn bn s c rt ra khi b bng bm ht bn.4.9.2. Tnh tonLu lng bn d cn x l mi ngy: QV = QI + QUASB + QII = 2,63 + 1,26 + 4,7 = 8,59 (m3/ngy)Din tch ca b nn bn ng c tnh da theo cng thc:F = 323 28, 59 /1,19( )0, 3 / . .24 /VoQ m ngaymq m m h h ngay Trong :GVHD: ThS. Nguyn Xun Hon Trang 57 n mn hc X L Nc Thi Lp HMT1qo: Ti trng tnh ton ln din tch mt thong ca b nn bn (m3/m2.h), qo= 0,3 m3/m2.h ng knh ca b nn bn :D = 4F=4.1,19= 1,23 (m)ng knh ng trung tm:d = 0,1D = 0,1.1,23 = 0,123mng knh phn loe ca ng trung tm:d1 = 1,35d = 1,35.0,123 = 0,17 (m)ng knh tm chn:dch= 1,3d1 = 1,3.0,17 = 0,22 (m)Chiu cao cng tc ca b nn bn :H = qo.t = 0,3.10 = 3m Vi t : thi gian nn bn. Chn t = 10h quy phm (10 12h).Chiu cao tng cng ca b nn bn :Htc = H + h1 + h2 + h3 = 3 + 0,3 + 0,3 + 0,8 = 4,4 (m)Trong :h1: chiu cao t mc nc n thnh b (m).h2: chiu cao lp bn (m)h3: chiu cao phn chp y b (m)Mng thu ncMng thu nc t vng trn theo thnh b, cch thnh b 0,3m.ng knh mng thu nc:Dm = 0,8D = 0,8.1,23 = 0,98 (m)Chiu di mng thu nc:Lm= D = .1,23 = 3,86 (m)Lng nc tch ra khi bn:99,2% - 97% = 2,2%Lng bn sau khi nn:Qb = QV 2,2%QV = 8,59 2,2%.8,59 = 8,4 (m3/ngy).GVHD: ThS. Nguyn Xun Hon Trang 58 n mn hc X L Nc Thi Lp HMT1Tnh cng sut bm ht bn : Thi gian ht bn 20 pht, 8h ly bn 1 ln.N = 1200.9, 81.8.0, 00230, 3( )1000 1000.0, 8gHQkW Trong : Q : lu lng bn sau khi nn (m3/s).H : chiu cao ct p ton phn. H = 8 (mH2O).: khi lng ring ca bn sau khi nn (kg/m3).= 1200 (kg/m3). : hiu sut bm (%). Chn = 0,8.Cng sut thc t ca my bm:NTT = 1,2.N = 1,2.0,3 = 0,36 (kW)Chn 2 bm cng sut 0,36 kW hot ng lun phin nhau .Tng hp thit k b nn bnThng s Gi trGVHD: ThS. Nguyn Xun Hon Trang 59 n mn hc X L Nc Thi Lp HMT1Lu lng bn sau khi nn, Qnn(m3/ngy) 8,4ng knh b nn bn, D(m) 1,23ng knh ng trung tm, d(m) 0,123ng knh phn loe ca ng trung tm, dl(m) 0,17ng knh tm chn, dch(m) 0,22Chiu cao tng cng b nn bn, Htc(m) 4,44.10. My p bn 4.10. My p bn4.10.1. Nhim v:Cn sau khi qua b nn bn c nng t 3 8% cn a qua my p bn gim m xung cn 70 80%, tc nng cn kh t 20 30% vi mc ch:- Gim khi lng bn vn chuyn ra bi thi.- Cn kh d chn lp hay ci to t hn cn t.- Gim lng nc bn c th thm vo nc ngm bi thi.- t gy mi kh chu v t c tnh.4.10.2. Tnh ton:Lu lng cn n lc p dy ai:093 , 097 1002 , 99 100. 35 , 0100100.21PPQ Qv b m3/hTrong :QV: lng bn a n my p, QV = 8,4m3/ngy = 0,35 m3/h P1: m ca bn d, P1 = 99,2%P2: m ca bn sau khi nn b nn bn, P2 = 97%GVHD: ThS. Nguyn Xun Hon Trang 60 n mn hc X L Nc Thi Lp HMT1Gi s lng bn sau khi nn c C = 50kg/m3, lng cn a n my p bn l:Q = C.Qb = 50 kg/m3. 0,093 m3/h = 4,7kg/h =112,8kg/ngy.My lm vic 6h trong 1 ngy, 1 tun lm vic 3 ngy.Lng cn a n my trong 1 tun: 112,8 . 7 = 789,6kg.Lng cn a n my trong 1h:h kg G 87 , 433 . 6789,6 Ti trng cn trn 1m rng ca bng ti do ng trong khong 90 680kg/m chiu rng bng gi. Chn bng ti c cng sut 100kg/m rng gi.Chiu rng bng ti:mGb 44 , 010087 , 43100 Chn my c chiu rng 0,5m v nng sut 100kg/m rng gi.4.11. 4.11. H sinh hc thc vt H sinh hc thc vt4.11.1. Nhim vNhim v ca h sinh hc l nhm n nh tnh cht nc thi v tng cng hiu qu kh cc cht bn hu c cn li trong nc thi. Trong h, nc thi c lm sch bng qu trnh t nhin nh s c mt ca lc bnh.4.11.2. Tnh tonNc thi sau khi qua b lng II, hm lng BOD5 gim khong 20%.BOD5 ca nc thi vo h sinh hc l 72mg/l.Hiu qu x l BOD5 ca h sinh hc l 60%. Nh vy, hm lng BOD5 ca nc thi ra khi h sinh hc l 28,8mg/l (t tiu chun loi B)Din tch ca h sinh hc c xc nh:2( ) (72 28,8)5000,12( ) 1200( )1000. 1000.180a tL L QF ha mOM GVHD: ThS. Nguyn Xun Hon Trang 61 n mn hc X L Nc Thi Lp HMT1Trong :La: BOD5 ca nc thi u vo (mg/l).Lt: BOD5 ca nc thi u ra (mg/l).Q: lu lng nc thi (m3/ng)OM: ti trng b mt (kgBOD5/ha.ngy), c th ly 150 350 kgBOD5/ha.ngy ph thuc vo iu kin nhit , lng nng. Chn OM = 180 kgBOD5/ha.ngy.Th tch ca h:W = F.H = 1200.0,8 = 960 (m3)Trong : H: Chiu cao hu ch ca h (m3). Chn H = 0,8 m.Chiu cao d tr khi tri ma l 0,3 m.Chiu cao tng cng ca h l H = 1,1m.Thi gian lu nc trong h:960.2446( )500Vt hQ Chn chiu di ca h sinh hc l: L = 40m.Chiu rng ca h sinh hc l B = 30m.Kch thc h sinh hc: B x L x H = 40 x 30 x 1,1 (m).GVHD: ThS. Nguyn Xun Hon Trang 62 n mn hc X L Nc Thi Lp HMT1CHNG 5: TNH KINH T CHNG 5: TNH KINH TGi thnh x l nc bao gm:Chi ph xy dng c bn v thit b (chi ph u t ban u).Chi ph vn hnh v qun l.5.1. Chi ph u t ban u Chi ph xy dng cng trnhSTT Cng trnhTh tch (m3)S lngn vn gi (VN/m3)Thnh tin (triu ng)1 Ngn tip nhn 22,13 1B tng1,500,000 33,1952 B lng ct 4,65 2 B tng 1,500,000 13,953 B iu ha 59,25 1 B tng 1,500,000 88,8754 B lng I 24,87 1 B tng 1,500,000 37,3055 B UASB 54,65 2 B tng 1,500,000 163,956 B Aerotank 52,22 1 B tng 1,500,000 78,337 B lng II 42,64 1 B tng 1,500,000 63,968 B nn bn 7,13 1 B tng 1,500,000 10,695GVHD: ThS. Nguyn Xun Hon Trang 63 n mn hc X L Nc Thi Lp HMT19 Nh iu hnh 1 40Tng cng 530,26Chi ph thit bSTT Thit b S lngn gi(VN)Thnh tin (VN)1 Li chn rc 2 800,000 1,600,0002Bm chm ngn tip nhn 2 10,000,000 20,000,0003Bm chm biu ho 2 10,000,000 20,000,0004Bmbn ti b lng I 2 8,000,000 16,000,000Bm t b lng I sang b UASB 2 8,000,000 16,000,0005 My cp kh2 50,000,000 100,000,0006 a phn phi kh 90 100,000 10,800,0007Mng rng ca b lng 2 2,000,000 4,000,0008 Bm bn b lng II 2 8,000,000 16,000,0009Bmht bn b nn bn 2 12,000,000 30,000,00010Mng rng ca b nn bn 1 1,500,000 1,500,000My p bn 1 100,000,000 100,000,00011 T in iu khin 1 18,000,000 18,000,00012H thng ngin k thut 30,000,000 30,000,000GVHD: ThS. Nguyn Xun Hon Trang 64 n mn hc X L Nc Thi Lp HMT113ng ng dn nc, dn kh 30,000,000 30,000,00014Cc chi tit phpht sinh 40,000,000 40,000,000TNG CNG 410,500,000Tng vn u t c bn bao gm chi ph khu hao xy dng 20 nm v chi ph khu hao my mc 10 nm.530, 260, 000 410, 500, 00067, 563, 00020 10VT + (ng/nm)5.2. Chi ph in nngHng mcCng sut (kW)S lngMy hot ngGi hot ngin nng tiu th (kW)Bm chm ngn tip nhn 1,4 2 1 6 8,4Bm chm b iu ha 0,7 2 1 24 28,8Bm bn ti lng I 0,6 2 1 0,17 0,1BmtblngI sangb UASB0,52 2 1 24 12,48Bm bn b lng II 0,78 2 1 24 18,72My thi kh 14 2 1 24 336Bm ht bn b nn 0,3 2 1 1 0,3Tng cng 404,8Gi cung cp in cng nghip: 1,200 ng/kWVy chi ph in nng cho mt ngy vn hnh:T = 404,8.1,200 = 485,760 ng/ngy = 177,302,000 ng/nm.5.3. Chi ph qun l v vn hnhS cng nhn vn hnh l 3 ngi, lng 1,8 triu/ thng v 1 k s, lng 3 triu / thng.Tng chi ph nhn cng l: TQL= 8,400,000ng/thng = 100,800,000ng/nm.5.4. Chi ph bo dng my mc thit bChi ph bo dng hng nm c tnh bng 1% tng s vn u t vo cng trnh x l.GVHD: ThS. Nguyn Xun Hon Trang 65 n mn hc X L Nc Thi Lp HMT1Tbd=0,01.67,563,000 =675,630 (ng/nm).5.5. Chi ph x l 1m3 nc thi Tng chi ph x l:TTC=67,563,000+177,302,000+100,800,000+675,630=346,340,630 (ng/nm). Gi thnh x l cho 1m3 nc thi:332, 083, 9351, 900500.365T (ng/m3)KT LUNTrong nhng nm gn y, ngnh chn nui nc ta c nhiu bc pht trin ng k. Nh c mt s chnh sch u t pht trin chn nui heo ca nh nc nn hin nay trn c nc xy dng nhiu m hnh trang tri chn nui heo GVHD: ThS. Nguyn Xun Hon Trang 66 n mn hc X L Nc Thi Lp HMT1vi quy m ln. Tuy nhin cng vi s pht trin cao ca sn xut l nhng vn nhim mi trng ca ngnh chn nui ang ngy cng trm trng. Nc thi chn nui cha rt nhiu hp cht hu c, vi khun, giun sn nu khng c x l kp s gy nn nhiu hu qu xu cho mi trng. Mt s c s chn nui tuy c xy dng h thng x l nc thi nhng do cn nhiu hn ch v kinh ph v k thut nn cht lng nc sau x l vn cha t tiu chun cho php.V vy vic nghin cu tm ra mt quy trnh x l hiu qu v ph hp cho cc tri chn nui l nhu cu tt yu v cp thit. Thnh phn nc thi chn nui ch yu l cc cht hu c v vy rt thun tin trong vic x l bng phng php sinh hc. Quy trnh x l nc thi chn nui m nhm xut c th x l tng i hiu qu cc thnh phn hu c trong nc thi. V vy cc c s chn nui nu c iu kin nn p dng quy trnh ny hn ch cc tc ng xu n mi trng do hot ng sn xut ca mnh gy ra.DANH MC TI LIU THAM KHO1. Trn c H, X l nc thi th, NXB Khoa Hc v K thut H Ni, 2006.GVHD: ThS. Nguyn Xun Hon Trang 67 n mn hc X L Nc Thi Lp HMT12. PGS.PTS Hong Hu, X l nc thi, NXB Xy Dng H Ni, 1996.3. TS. TrnhXunLai,Tnhton thitkcc cngtrnhxl ncthi, NXB Xy Dng H Ni, 2000.4. Lm Minh Trit - Nguyn Thanh Hng - Nguyn Phc Dn, X l nc thi th & cng nghip, NXB i Hc Quc Gia TP H Ch Minh, 2006.5. Mt s n x l nc thi.6. www.google.com.vnGVHD: ThS. Nguyn Xun Hon Trang 68