H p l NGH! KHOA H p C C O N G N G H E SINH HpC T O A N Q U 6 C 2013
XO" LY DONG THOI HO'U CO VA NITO TRONG MUOC THAI CHAN NU(!)I LON BANG PHUaNG PHAP SBR: A N H HUONG CLIA CH£ DO CAP NU'O'C THAI
Phan D 3 HCing', Pham Thj Hdl Thjnh, TrSn Thj Thu Lan
Vl^n Cong ngh$ mdi tnrdng. Vi$n Hin lim Khoa hgc va Cdng ngh$ VI$t Nam T 6 M TAT
Hi^u qui xii 1^ dong tbiri hihi co vii nito trong nirdc tlial chSn nuoi Ign cfia qui trlnb bi^ ho^ tinh theo me (Sequencing Batch Reactor - SBR) hai chu trinh thiSu - hilu khi cap nude hai lln (^ dugc oghiSn cftu. NinSc Ihii cban nuoi Ign da qua xu ly so bp lifin^
ham biogas dugc cAp thinh bai lln vio cac giai doan thieu khi v6i ba ti I^ cip nu6c (ti 1§ giiia lupng nuoc thai dugc cip lin thii nhit va tfing lugng nirdc diai dugc xtt ly moi me) khic nhau 1/2,2/3 vi 3/4. Anh hudng cna cac ti 1$ niy din hi^u qui xii ly COD, amoni vi T-N dS dwgc xic dinh bang thyc nghifm vi dugc so sanh voi kit qui d tni&ng hgp dp nu6c mpt lin. Hifu suit xii I^ T-N ly thuylt cung da dugc tlianh lip vi so sinh vdi b i ^ suit tbgc n^SnL Ket qui nghi^ ciiu (^ chi ra ring, v6i qui trinh SBR hai chu trinh Oiieu - hieu ktii, cip nu6c hai lln li m^t giii phip d€ ning cao hifu qui xic 1^ T-N ciia qui trlnh. Thp; nghifm cho thiy, khi ting ti 1^ cip mriic, liic diu hifu suit xii ly T-N se Hng, my nhien den m§t gim h ^ nhlt djnh hifu suit xii IJ T-N se giim trd lai.
Hifu suit xii ly T - N cr ci ba ti If cip nu6c nghien ciru dSu kha cao, trong d6 cr ti If 2/3 d^t cao nhlt, trong Idioing 85 - 90 %. Hifu suit xii ly T-N thuc nghifm cr cic ti If cip ninSc thip 1/2 vi 2/3 khi phfi hgp vdi hifu suit IJ thuylt. Hifu suit xii If COD d chl d§
cip nude hai lan ciing khi cao, SS - 90% d d tf c ^ nirdc 2/3, xip xl vdi trudng hgp <^p nude m^t lin. Cic thdng s6 vl tii trgng . COD vi til trgng.T-N cfia- qui trinh d?t ditgc cijng khi cao, tuong ling li 0,6 ± 03 kg-COD/(m'-ngiy) vi 0,16 ± 0,06 kg- N/(m'-ng4y).
Tie khda: Chl d? dp nuiS'c, Nude thii chin nu6i Ign, SBR, Xd ly dong thdi hiiu co vi nito
' MdrsAu
Vdi dinh huiftng phdit tri^n chSn nuSI t|p trung, chan nufli Ig-n qui m6 trang trgi cflng nghi$p dang du'g'c ph^t triln nhanh' -efA/i§t-Nam^Fengflh&ng-nam-gSH-aay7^^tfgflrtrang4r9i-trong^iahao9n2OO1--^0fri§ngtren-5fr%7Tianr20O9-^
tang 13,2 % (Cgc chan nufll, 2011) Hi#n nay ck nuae co khoang 8.500 trang trgi chan nufll Ig-n t|p trung, cung d p khoSng45%slnlircrngthitl9n(Cgcchannufli, 2011). Quy mO dan Ipnca nucrc nim 2012 kho5ng 26,5 tri#u con (Cyc tii6ng kg, 2012), so vol t6ng qu? d^t dai vk dan s6 day \k m$l con sfi rlit Idrn. Chan nuoi ign t|p tmng qui mfi Idrn trong difiu ki#n dl§n tlch trang trgi h?n hep vk gfin v*! eke khu d^n cu" dang dSn din mOJ lu-png Ifl'n chit thai chila nhilu phfin v^ nu*c tilu dugc th5i ra fong nliong khflng gian han che. dang gay ra nhQing tfic dgng mfll^tm'drng tiSu cyc den khu vgc trang tr^ii vk xung quanh. 6 Vi§t Nam, nu'fl'c thai chan nuOi l(7n chO yiu du'pc xil II scr bO bang bMifi biogas vklhokc h6 sinh hgc. Xii Vnki nude th5i chan nufli liyn md'i cht xO li so- b$ qua bl/hfi biogas cfln chO'a nhieu chfit hOu ca vh nito
"hvc tifip vko ngufin tifip nh|n gay ra fl nhiSm mfli tnrong vk hi#n tifpng phO du-Sng cho ckc thCry vi,rc. vl v|y \k khOng mong mufin. CAc cflng ngh| hi§n t^i dang kp dung trong xi> Ij? nu'fl'c thAi chSn nufli d nude ta nhin chung mdi ch? xi> \ii dugc mOt phan chfit hu'u co-, cfln cac thSnh phan dinh dirfl'ng nito vk pholpho gan nhu chua dugfc xi> 1;^.
•Qu^ trlnh SBR (Sequencing Batch Reactor) ik qui trlnh bCln hogt tinh du'g'c thyc ht$n thao mk. trong dfl cac giai dogn phfin ijrig vfi lang dugc thyK hi#n trong cOng mflt thifit tij. Vdi sv thay dii chfi dfi syc khi v6i ckc chu trinh syc khi - ngOng syc khi luSn phiSn cfl thfi thyc hl#n nhieu chu trinh hifiu - thilu khf nfii tilp \ukn phi§n trong cOng mi>t bfi phfin O'ng SBR. Nh& v$y, qufi trlnh nfiy cfl thfi xi> IJ dong thdi huu ca vfi nita. Cfic nghifin cii'u trudc dfiy (Chang Won Kim e(
a/., 2000; Bortone G. et a/., 1992; Song Van et al.. 2004) cho thfiy qufi Wnh SBR cfl hi#u qua xi> ly huu ca vfi nlta khfi caia dfii vdi nude thai chfin nufli l^n,
Vd] muc dich nghifin CLPU phfit triln cflng ngh§ xu' ly hifiu qua dfing thdi hOu ca vfi chfit dinh du&ng trong nuac thfii ngfinh chSn nufli Ip'n, trong nghifin cuu tnrfl'c (Phgm Thj Hai Ttijnh vfi dfing tfic gifi, 2012), chOng tfli dfi nghifin CCPU finh huAng cOa mgt sfi difiu ki#n v|n hfinh nhu ty lfi COD/T-N (ti le glQ'a nhu cau oxy hoa hgc vfi tflng nito) vfi chfi dO syc khi den hieu qua xi> ly COD vfi T-N cua qufi trinh SBR doi vdi nudrc thai chfin nufii da qua xu ly ky khi. Vfli chfi dfi hai chu trlnh thilu - hieu khi thich hgp. hifiu qufi XCP ly COD vfi T-N dgt kha cao, tuang O'ng Ifi khofing 90 % vfi 80 - 85 %. Tuy nhifin nfing dg T-N trong nude thfii chfin nufli Ipn Ifi rfit cao vfi thay dfii trong trong khofing khfi rfing, yi vfiy nghifin ci>u nfinq cao hieu qufi xi> i j nita cua qufi trinh nhfim dap ung mflt cfich fin dinh cfic quy chufin xa thfii Ifi rat cfin thilt. Trong noh^n CO'U nfiy finh hudng cOa ti Ifi cfip nufl'c thfii den hifiu qua xii ly cua qufi trlnh SBR hai chu trlnh thieu - hilu khi cip nude hai lln da dugc nghifin cdu vfi so sanh vdi chfi do cfip nude mfit Ifin. Hifiu suit xu 1^^ T-N ly thuylt cua qufi trlnh cOng-da dugc thifit Ifip vfi so sfinh vol hi$u sufit xd IJ thyc nghifim.
HIEU SUAT XLF Lt T-N LV THUYLT COA QUA TRINH SBR HAI CHU TRJNH THl^U - HlfiU KHi CAP NtyCfC HW LAN Trong nghifin cdu nfiy qufi trinh SBR dugc thyc hifin theo hai chu trinh thilu - hilu khi vfi nude thfii dugc cSp lfim hai ifin vfio khofing thdi gian dfiu cOa cfic giai do^n thlfiu khi nhu chi ra d hlnh 1 va bfing 2. Cfip nude thfii Ilin hai vfio giai doan thifiu khi thd hai nhfim tfin dyng ccr chfit huu ca c6 san trong nude thfii d l thyc hi#n qufi trinh khd nitrat/nitrit lfi sfin phim cCia giai doan hifiu khf thd nhfit, td 36 cfi thfi nfing cao hifiu sufit xd IJ T-N cOa qufi trlnh,
Quan hfi gida hifiu suit xd ly T-N ly thuylt cua qufi blnh SBR hai chu trlnh thlfiu - hilu khi cfip nu6« hai ifin vfi fi Ig cfip
nude duge thfinh Ifip dya trfin phuong trinh cfin bfing vfit chfit cua qufi trlnh vdi cac gifi thifit sau: (a) Du ca chfit huu ca
dio cfic qufi hinh nitrit/nltrat hfia d efic giai dogn thieu khi (ngung syc khi), vfi qufi trinh khd nitrat/nitrit trong cfic giai
doan thifiu khi xfiy ra hofin tofin; (b) Tofin bfi lugng nita sau xu ly hifiu khi deu ton tgi dudi dgng nitrit vfi/hofic nitrat, tdc
Ifi tofin tJfi lugng fUa huu co' dfiu dugc chuyin thfinh dgng vfl ca va qufi trlnh nitnt/nitrat hfla (chuyin hfla amoni thfinh
- nitrit vfi/hofic nitrat) xay ra hofin tofin; (c) Lugng nita chuyen hfla vao t l bfio vi sinh vfit Ifi khfing dfing k l so vdi lugng
HOI NGHi KHOA HQC C(!lNG NGHE SINH HQC T O A N Q U 6 C 2013
chuyen hfia thfinh khi nita: (d) C6 the bd qua l u g n g nitrit/nitrat bj k h u trong giai dogn Ifing va x f i ; va (e) Nong dfi nitrit vfi nitrat dfiu vao la khflng dfing ke.
T d cac gifi thifit tren, suy ra rfing l u g n g nito c h u y i n hfla thfinh khi nita (N2) d giai doan thifiu khi thd nhfit chinh Ifi lug'ng T-N cfln Igi trong bfi phan dng sau khi xfi nude thfii da x d ly d mfi x d ly tnrdc dfl, t d c Ifi nVC.
Ni.aVCo
nV.C
'Ridov,c
Chu binh thilu - hifiu khi 1 Chu trlnti thlfiu - htfiu khi 2 Ling, xfi Hlnh 1 . Su d6 Vfn hfinh v i cfin tiang v ^ chat cua qufi trinh SBR hal chu trinh thieu - hifiu kiii cfip n u 4 c hal lan
a: tl H cip nude (01$ gida lugng nude thU cip vao lin mft vit6ng lirgng nude thii xdl^ tmng m^t mi): V: lugng nude Mlxdli' tmng mSi mi; Q, va C: n6ng dg T-N trong nu^ diii diu vio vi diu ra; KSHbru nude |V J$ g u a lugng nude cdn Id trong bi SBR sau khi xi nude thai dSxdt^vi lugng nude thSxiri^ trong mdt mi): nV a lugng • nui*c thii cdn lai tmng bi SBR sau khi xi nude thai daxirly
Theo gifi t h i l t (b), toan bO l u g n g T-N do n u d e thfii cfip ifin mfit mang vfio [aVCo) sfi chuyfin hfla thfinh nitrit v f i / h o | c nitrat sau giai dogn hifiu khi t h d n h f i l V f i theo gifi t h i l t (a), tofin bg l u g n g nfiy sfi c h u y i n hfla thanh N3 sau giai d o g n thlfiu-khlthdhai.
Phuong trlnh cfin bang vfit d i f i t dfii v d i thfinh phfin T-N cho mgt me x d 1^ n h u sau:
" Lugng T ^ v a o - Lirgng T-N ra = L u g n g nita (nitrit/nitrat) chuyfin hoa thfinh Hz: hay:
[orCp + Cl - o ) C C J -VC = nVC-t- dVCf hay
(1) (2)
Trong phuong trlnh (1), aVCo vfi (1 - a)VCo la l u g n g T-N do n u d e thai mang vfio d cfic lan cfip; VC Ifi l u g n g T-N d o nude thfii mang ra; nVC vk aVCa n h u d f i giai thich d trfin, Ifi l u g n g nito d u o c chuyfin hfla Ihfinh khi nito trong hal giai dogn'thifiu khf.
T d (2) ta nhfin d u g c phuong trinh hifiu sufit x d 1;^ T-N (r|) n h u sau:
i j ( % ) = - (3)
T d (3) cfl thfi ^ f i y rfing, n l u cac gifi thifit nfiu h'fin d u g c thfia man thi hifiu sufit x d 1^ T-N cfing cao khi a vfi/ho^c n cfing Idn. Tuy nhifin, trong t h y c t l khi a Idn h o n mgt gifi tri nfio dfl thi l u g n g n u d e thfii cap ifin hai qufi nhd, do do khflng cUng cfip dO CO chfit h d u c a cho giai dogn ^ i l u khf t h d hai. VI vfiy khi do hifiu sufit x d 1;^ T-N sS giam. N h u v9y, de dgt d u g c hifiu qufi x d 1;^ T-N cao nhfit, toi u u hda tl Ifi cap n u d e Ifi rfit c^n thifit.
Bfing phuong phfip t u o n g l y n h u trfin ta cfl the xfic ffinh d u g c hifiu sufit x d ly T-N ly t h u y l t trong t n r o n g h g p cfip n i ^ d c mCit ifin b'ong giai do^n t h i l u Mit-ttid nhfit n h u sau:
• J C % ) = (4)
Bang 1. Thfinh phfin ciia nip6'c thai chan nudi Ion Irong n g h i i n c d u
T d (3) vfi (4) cfl thfi thfiy rfing, theo ly t h u y l t , cfip n u d e hai ifin vfio cac giai doan t h i f i u k h l v d i 6 Ifi thfeh h g p se cho hi#u sufit x u ly T-N Idn h o n so vdi t r u d n g h g p cfip n u d e mOt ifin I d dfiu.
NGUYfeN U $ U v A PHU-ONG P H A P N u d e t h f i i
N u d e thfii s u dyng trong nghiSn c d u nay Ifi n u d e thfii chfin nuOi Ign da qua )td 19 ky khf b i n g ham biogas cfl dgc t n f n g n h u d Bang 1 . N u d e thai c f l nfing d ^ chfit hiru c o va rvto cao.
Thdng s6 pH CODc (mg/L) N-Nm*(mQ/L) T-N (mg/L) T-P(mgfl.)
Khofing dao dOrig 6 , 8 - 7 , 4 850-1400 1 9 0 - 3 9 0 2 0 0 - 4 1 0 2 5 - 6 6 H f thifit b i SBR p h o n g thf n g h i $ m
Cfic nghifin c d u d u g c thyc hien trfin hg thifit bj SBR c6 dung tlch h d u ich 20 L n h u trong nghifin c d u b v d c (Pham Thi Hfii Thinh v f i dong tfic gifi, 2012). Khdng khf chl d u g c syc vfio hfi SBR trong cfic giai dogn h i l u khf
vdi toe ao 10 L/phOt. Bcrra cfip n u d e thfii, b o m hot n u d e sau x d II Ifi b o m dinh l u g n g c6 t h i dieu chmh d u g c luu l u g n g . .. Chfi dfi hogt dOng (thdi gian hogt dfing, dimg) cOa cfic b a m , may thfii khf v f i mfl t a khufiy cd thfi cfii ^ t , thay dfii d u g c vfi d u g c difiu khifin t y dfing. Cfic »iflng sfi p H , O R P (thfi oxy hda k h u ) , DO (nfing dO oxy hoa tan) d u g c hign thj t r e n bfing difiu khifin vfi d u g c kfii nfii v d i may tinh.
Trong'qufi trinh thf nghifim, nfing dd bun (MLSS) d u g e duy tri tnang khofing 4000 - 5000 mg/I; pH trong khofing 7 , 0 - 8.5; DO trong khofing 4 - 6 mgrt (Insng lOc dang syc khi); l ^ Ifi COD/T-N > 3, trung blnh 3,75, thdi gian tiru 2 ngfiy.
HOI NGH! KHOA HOC C O N G N G H E SINH HQC T O A N Q U O C 2013
~caircfti dg mi nghigrti
Bfing 2. Cac c h i 0$ v | n hiinhThdi gian m$t me, qicr
~ ~ - n > . „ „ ^ g i a i dogn TI 1$ cfip n u d c ^ - - , . ^
3 = 1 / 2 a = 2/3
1 1 2 1 3 1 4
Chu trlnh t h l f i u - h l l u W i l l • A lA , F A . F A, F
0 1 O 0 0
5 1 6 L '' 1 8
Chu trinh thieu •- hiSu A2A F A , F A F
] 9 1 10 khi 2
0 2 O O 0-
11 12
Lang,xfi S S S
D D D A: Thiiu khi (Anoxic, gid doan khdng sue khi); O: Hiiu khi (OOc, giai doan syc khli; S: Ling (Settling); D: Xi (Decanbng). F: dp nude thai (Feeding, trong 30 phiit diu Bin cOa ma giai doan thiiu khf); a: Tj? 1$ cap nude (S14 giira lugng nuac thii cip v^ lin mft vi tong lugng nude thii xd ly' trang mft me)
Ckc nghifin cdu deu d u g c t l l n hfinh v d i hai ehu trinh thifiu - h i l u khf n h u trinh bfiy d Bang 2. Thdi gian ciia cae giai dogn thlfiu khi t h u nhfit vfi t h d hai t u o n g dng lfi 1 h v f i 3 h. Cfic giai dogn hifiu khi dfiu d u g c t h y c hifin trong 3 h. Trong mfii mfi x d ij 12 h, n u d e thfii d u g c cfip hai lan, moi Ifin 30 phOt vfio thdi gian dfiu cua cfic giai do?n thifiu khi. Tfing l u g n g n u d e thfii cfip vfi rOt ra trong mfil mfi x u 1^ lfi 5 lit vfi lugng n u d e thfii cfln Igi trong bfi SBR sau moi mfi x d ly Ifi 15 lit (nghTa la n = 3). Tl Ifi cfip n u d e a (tl Ifi giua l u g n g n u d e thfii d u g c cfip Ifin t h u nhfit va tfing l u g n g nude thfii cap eho mfit mfi) d u g e thay doi v d i ba chfi dO 1/2, 2/3 vfi 3/4. Thdi gian lang vfi xfi cufii mfii mfi x u 1^ dfiu Ifi 1 h. • PhiFa>ng p h f i p phfin t i c h
COD d u g c xfic dRnh bang phuong phfip chufin d f i dicromat kali theo TCVN 6491:1999, s d dyng thifit bj phan d n g Thermoreactor TR 320 (Merck, D d c ) . N - N H / d u g c xfic ^ n h bfing phuong phfip Phenat, theo Standard Methods 1995.
' N - N O a ' d j g c .xfic dinh bfing p h u o n g phfip trao phfi dung axit sunfosallxylic, theo TCVN 6180:1996. N-NOi" d u g c xfic dinh bfing phuong phap trfic phfi hfip thy phan t d theo TCVN 6178:1996. T-P d u g c xfic a[nh theo phuong phfip so mfiu arft ascoxbic, theo standard Method 1995. T-N d u g c xfic ^ n h trfin
mfiy phfin tieh TOC-N (model T N M - 1 , Shimadzu, Nhfit Bfin) bfing
" p h u o n g phfip d f i f c a c h g p cRfit nito thfinh NO d 72CPC efl xOc tac vfi phfit hifin bfing detecto quang hfla.
K ^ T QUA V A T H A O L U A N
A n h h u d n g cfta ti Ig cap n u ^ den h i f u suat
Kfit qua d Hlnh 2 d i o thfiy, hifiu sufit x u ly COD d ba fi le cfip nude da nghifin c u u dfiu kha cao. Tuy nhifin hifiu sufit d tl Ifi cfip n u d e a
= 1/2 It nhlfiu thfip han vfi It in djnh h o n d cfic tl Ifi flfip n u d e a = 2/3 vfi 3/4 (80 - 90 % so v d i 85 - 90 % ) . Khi 11 Ifi a tang Ifin, h>c la l u g n g n u d e cfip Ifin hai sfi gifim dl, d o dfl tfil trgng COD cho chu trlnh thifiu - hifiu khi t h u hal se gifim 01. d i n den hifiu qufi x u ly COD cCia ehu trlnh t h i l u - h l l u khf thd hal se trifit dfi h o n . Difiu nfiy dfin tdi hi#u s u i t x d IJ COD se tang Ifin khi tfing tl Ifi a n h u kfit qua ^^
nhfin d u g c d trkn. Trong ngWfin c d u trirdc (Phgm Thi Hai Thinh va dfing tfic gifi, 2012), hifiu sufit x d t} COD trong t n r o n g hgp cap - 400 nude mOt l l n (chf cfip nude mOt Ifin duy nhat vfio rffiu g i a i d o a n g ' ™ thlfiu khf t h d nhfit) dat d u g c Ifi 90 - 93 % . N h u vfiy, hifiu sufit x d 1^ ^ COD trong t r u d n g cfip n u d e hai ifin ed phfin thfip h o n so v d i tn/dng x 200 hgp cfip n u d e m^t lan. Kfit qua nfiy eOng Ifi hfi qufi cua nhung ly do ± dk d u g c nfiu trfin.
A n h h u d n g cOa t y Ig cfip n u d e dfin h i f u qufi x d 1;^ n i t a ° Hl$u qui xu-1$ amoni
Hifiu qua x u ly' nito amoni (N-NH4*) 6 cfic ti lfi cfip n u d e khfic nhau d u g e thfi hi#n trfin Hinh 3. Kfit qufi c h o ttiay vfl'i N-NH4* vfio dao dfing trong khofing 190 - 390 mg/l, hifiu sufit chuyfin hfla amoni gan n h u hofin tofin. dfiu xfip xi 100 % cho cfi ba t r u d n g h g p , nfing dg-N- NH4* trong nufl« da x u 1^ hfiu h i t d a t d u d i 5 mg/l. Kfit qufi nfiy ehdng tfl thdi gian cua cfic giai dogn hifiu khi dG dfi dam bao hfiu h i t tofin bfi l u g n g N-NH4'' cfl frong nude thfii dfiu d u g c nitrit/nitrat hfla.
H / | u qui khv nItraVnitrit
Nfiu qufi trlnh k h u nitrat/nitrit trong cfic giai dogn thifiu khi xfiy ra khfing trifit dfi, nita s f i tlch ty Igi trong hfi d u d i dgng nitnt vfi/hogc nitrat (san p h i m cOa qufi trlnh chuyfin hfia amoni v f i nito h d u c a Irong efic giai dogn hifiu khi]. Tuy nhifin kfit qua d Hlnh 4 eho thfiy, trong khi nfing dfi nita amoni vfi T-N dfiu vfio h f o n g d n g trong cac khofing 190 - 390 mg/l vfi 200 - 410 mg/I thi tfing nfing d $ nita nitrit vfi nitrat b'ong nufirc thfii dfiu ra chl trong khofing 1 5 - 5 5 mg/l. Kfit qufi nfiy ehdng tfl qufi binh k h u nitrat/nitrit trong cfie giai dogn thieu
• CODvio "COOra
Thoi gian, ngiy Hlnh 2. Anh hudng ciia t^ 1$ cap nirdc den hl#u
s u i t x d 1;^ COD
• N-NH4+vao •N.NH4+ra
C^I
:r^. •tfjfv^
ThMfllan. noay Hlnh 3. N-NHt* vfio.'ra vfi hIBu suJit x d 1;^ N-NHj*d
c i c tl I I cap nude khic nhau
• N-N03-ra a = 1/2 !
BN-N02 a = ra 2/3
I-N03- + N«02- 8 = 3/4 1
a. I ' 1
^ ^ ^ ; r. i 1 '^fil^k
* ^ . %
Q ^9 T ^ l
ThM gian. ngay Hlnh 4. NSng d$ N-NO] v i N-NOi' dfiu ra d c i c
ti If c i p nirdc khae nhau
HOI NGHI KHOA HOC C O N G NGHE SINH HOC T O A N Q U O C 2013
B7.N vSo "T-N ra i
^ i ^ ^ m , -feaj! u ^ . - 4
^ r\/^^^
a = M2 \ a = 3/4 | 3 = 2/3*v*!'''n'0-iiun*%!i ittftmf
llM (13 XfiV r a K n a n u o i ' vja,,. WW . ^ u , , , . 5 , . . - „ . . - , r Y ' i 9 ..>-,,3 .^ . . . u , , , , u i , ,a •i>iia> uu._.n - - - h o a = 1 / 2 Idn so v d i hai trudng h g p con Igi. Can luu y rang, l u g n g amoni vfi nito h d u c a do n u d e thai cfip l a " " 3 ' m^ng vfio se duge chuyfin hfla thfinh nitrit va/hoge nitrat trong giai dogn hifiu khi t h u hal vfi sfi d u g c tich t u Igi trong hg d u d i cfic dgng nfiy vi khfing d u g e chuyfin hoa hfip. Do dd khi l u g n g nufl'c thfii d p lan hai tfing (tdc khi a nhd) thi Wia nfing tich l y nitnt/nitrat eua hfi se tang. D f l ia ty do vi sao tfing nfing dg nito nihit vfi nitrat trong n u d e thfii sau x u ly o trudng hgp a = 1/2 cao hon cac frirdng h g p kia.
Hieu qua xu ly T-N
Myc dich cOa cfip n u d e hai Ifin lfi tfin dyng c a chat h d u c o cd s i n trong n u d e thai d l eung cfip cho qua trinh k h u nitrat/nitrit trong giai dogn thlfiu khf t h d hai, nhfim nfing cao hifiu qua eOa qufi trinh nay. _ VI vfiy, cfip nude hai Ifin ed thfi nfing cao hifiu qufi x u ly- T-N cOa |
tofin bO qufi trlnh. ^ ' Hifu qufi to If T-N d cac ty 1$ cfip n u d e khfie nhau trong difiu kifin i -
tfii trgng COD 0,6 ± 0,2 kg^OD/(m^-ngfiy). tfii trgng T-N tfnh theo thfi tlch 0,16 ± 0,05 kg-N/(m'ngay) vfi h'nh theo bun 0,03 ± 0.01 kg- N/(kg-MLSS-ngfiy) d u g c the hlfin trfin Hlnh 5. K i t qua nghifin c u u cho thfiy, higu sufit x u ty T-N d ea ba d i l d$ dfiu khfi cao, trong dfl -s dgt cao nhfit d che dg a = 2/3. trong khofing 85 - 90%. Nfiu eh? tinh z rifing tfing nito Kjeldahl (TKN), h i f u sufit x u ly dgt trong khofing 95 K - 99% Nhu da trinh bfiy d phfiri trfin, hifiu sufit x d IJ T-N, theo 1^ '•- thuylt, sfi tfing khi tfing fl Ifi cfip n u d e a. Tuy nhien, trong thyc t l 'x khi a tfing d i n mfit gidi hgn nfio dfl, l u g n g n u d e cfip Ifin hai t r d nfln •«
qufi nhfl. khfing cung cfip dii ca chfit h d u eo cho qufi trlnh thlfiu k h i ^ t h d hai, vi vfiy qufi trinh k h d nitrat/nitrit d giai dogn nfiy xfiy ra kfim * trifit dfi. d i n d i n hifiu qufi x u 1;^ T-N gifim. Kfit qufi t h y e nghifim ^ nhfin d u g c cOng cd xu h u d n g nfiy, h i f u s u i t x d 1;^ T-N tfing khi tfing a t d 1/2 Ifin 2/3, nhung sau dfl giam khi tfing a Ifin 3/4. K i t qufi trfin Hlnh 5 eOng cho thfiy rfing hifiu sufit t h y c n g h i f m d cfic trudng hgp a = 1/2 vfi 2/3 khfi tuong dfing vdi h i f u sufit ly t h u y l t (62 - 8 8 % so vdi 87,5% dfii vdi t i r d n g hgp a = 1/2; vfi 85 - 90 % so v d i 91,7 %
dfii v d i tnrdng h g p a = 2/3). Tuy nhien, sai khfic nfiy tfing Ifin khi l a n g a ISn 3/4 (84 - 88% so v d i 93.7%). Kfit q u f i nfiy m9t ifin nira cho thfiy khi a cfing Idn, Idific b i f t gida hifiu sufit t h y c tfi vfi 1;^ thuyel cfing Ion.
So sfinh kfit qufi cOa nghifin cihj rifiy v d i nghien c d u tordc cCIa chung toi (Phgm Thj Hal Thinh vfi dfing tfic gia. 2012), thfiy rfing c h l d$ efip nude hai Ifin cJio h i f u qua x u ly T-N eao vfi fin dinh h o n so v d i c h l dg cap nufl'e m$t Ifin trong mfit mfi (Bfing 3).
Mfit sfi k i t qufi nghifin cdu x d ly n u d e thfii chan nufli Ign bfing qufi trinh S B R hogc t u o n g t y cung d u g c tfing h g p trong Bfing 3. Trong cfie nghifin c d u nfiy, nghien cuu cua Zhang vfi dfing tfic gifi (2006) cho h i f u qua x d ly cao hon cfi, d o i v d i cfi COD vfi T-N; tfii trong COD vfi T-N cung dgt rfit cao. N u d e thfii trang nghien c d u nfiy cfl COD vfi t i I f C O D / T - N rfit cao vfi efie tfic gifi da d u a thfim cac giai dogn ky khf vao t r u d c vfi giua cac giai dogn thifiu khf/hifiu Idii, do d d dfi nfing eao d u g c tfii trgng x d [) COD. Mfit khfic cfic tfic gifi da thyc n g h i f m d thdi gian l u u tuong doi I d n , tl I f COD/T-N (7,5J vfi tl I f luu n u d e {n = 9) rfit cao, vi v | y cung da nfing cao d u g c h i f u sufit x d 1]^ T-N (trong t r u d n g h g p nfiy l i l f u s u i t 1;^
thuylt lfi 96,7%). Nghien cdu cua ehung tfli d u g c thye h i f n d tl I f luu n u d e thfip h o n (n = 3, h i f u sufit 1;^ thuyfit 91,7%), cfl lfi dfiy Ifi m f t trong cfic y l u tfi lfim t ^ o h i f u qua x u 1;^ T-N chua cao bang nghifin c d u trfin. So sfinh v d i kfit qufi nghifinjsdu t:ua cfic tfic gifi cdn Igi, kfit qua trong nghien cdu nfiy eOa chOng tfli ed phfin nhinh h a n vfi hifu-sufit cQng n h u tfii trgng x d ly.
Bdng 3. Tfing hgp in9t so k i t qufi nghiin cdu
T h M gian. ngay
T^cgla Bortone G. (1992) Chang Won Kim (2000)
ZhLJian Zhang (2006)
Jiang Cheng (2011) Mohammad N. (2011) Nghifin cdu tnrdc (cfip nude 1 ifin) (fhgm Ttij Hii Thinh, 2012) NghiSn cdu nfiy (a =2/3)
Dllu klfn thi nghi$m Thdi gian liru (ngfiy) 10
3.3
3 4.7
i
2
Tai trgng (kg/(m'-ngSy)) COD 0,37 1.0
2.1
0.23 0.42 0,7 ±0,2 0,6 ± 0.2
T-N 0,13 0.2
0,28
0,095 0,36 0.18 ±0.05 0.16 ±0.05
Hi$u qufi xd 1^ (%) COD
(TOO - 9 3 5 7 - 8 7
96,3
57 60,3 9 0 - 9 3 8 5 - 9 0
N-NH4*
9 1 - 9 5
100
92
97 -100 - 1 0 0
T-N hoac (TKN) ( 8 8 - 9 3 )
97.5
(91) 61 8 0 - 8 5 8 5 - 9 0 (96-99)
Ghi.chu SBR cfip nude m$t ifin SBR cfip nirdc mot ifin SBR cfip ni/dc hal ifin. .a
= 2/3. 0 = 9; qui trlnh vfin hSnh: Ky khi - thlfiu khWiifiu khi - ky khi - Ihilu VhUtviu khf Syc khf Uiin phifin cfip nudcRSntyc SBR cfip nude mdt Ifin SBR cfip nude m$t Ifin SBR cfip mrdc hai ifin, a
= 2(3. fl =,3
HOi NGHI KHOA HQC C 6 N G NGHE SINH HQC TOAN QU6C 2013 _JK£nii&«_
V d i qua trlnh SBR hai chu h-inh thieu - hifiu khf. cfip nude hai ifin lfi mdt gifii phfip dfi nang cao hifu qua xi> \'j T-N cua qufi trinh. T h y e nghifm cho thfiy, khi tang fi If cap n u w : ( f i l f giua l u g n g nuiirc thfii efip lan t h u nhfit vfi tong lugng nufl'c thai x d ly trong m f t me), luc dau h i f u suat x u ly T-N se tang, tuy nhifin dfin m f t gidi hgn nhfit d|nh hifiu sufit xi> \j T-N se gifim trd Igl.
H i f u sufit x d ly T-N d ea ba ti I f cfip n u d e nghifin c d u dfiu kha cao. irong do d l i If 2/3 dgt cao nhfit, bTang khofing 85 - 90 %. H i f u suat x d \^ T-N thyc nghifm d efic ti If cfip nude thap 1/2 vfi 2/3 khfi phu hgp vdi hifu sufit 1} thuyfit H i f u sufit x d ly COD d chfi d f cfip nude hal lan cung kha cao, 65 - 90% d 6 If cap nude 2/3, x i p xl vdi tnrdng hgp cfip n u d e m f t Ifin.
Cfic thflng sfi lien quan d i n toe d f eua qufi trinh Ifi tfii trong COD vfi tai trgng T-N dgbdugc cung khfi cao, t u o n g dng la 0.6 ± 0.2 kg-COD/(m^ngay) vfi 0.16 ± 0,05 kg-N/(m^nga^.
Ldlcanxm
Cong trinh tidy dupe hodn thdnh vdi su ho trp ve kinh phi cua di tdi cip nha nirdc KC.08.04/! 1-15.
T A I U ^ U THAM K H A O
Bortone G., Gemelli S., Rambaldi A. and Tllche A. (1992) NitrifKalion, Denitrification and Biologit^T Phosphate Removal In Sequencing Batch Reactors Treating PiggeryWastewaler. Wat Sd Tech 26(5-6): 977-985. .
Chang Won Kim, Myung -Won Chd, Jl-Yeon Ha {2000) Opbmazalnn of operating moda for sequedng batch reactor (SBR) treating piggery wastewater with high nitrogen, 2*./nl. Sym. on SSR Tecfmctogy/rtM, 1 0 - 1 2 , July, France,.
Cijc chfin nufli (2011) Bfio cio bfio v# mfli tnrdng trcmg hogt dgng chfin nudi giai doen 2005 - 201() vfi djnh hudmgdln'nfim 2020.
Cyc thfing kfi (2012) Tinh hinh kinh t l xfi h$i. ' _ _ ^ _ _ _ _ _ ^ ^ Jiayang Cheng. Bin Liu (2011) Nltridcation/Denitrlficallon In Intermittent Aeration Process for Swine Wastewater Treatment Joumd of
Environment E^^neon^g^27{S)•.705•7^t.
N. Mohammad, J. Keum. Md. J. Alam (2011) Treatment of Swine-Wastewater Using Sequencing Batch reactor. Engineering in Agriculture Environment and Food 4(2): 47 - 53.
Phgm Hij Hfii Thinh. Phan Ofi HCing, Tifin T i j Thu Lan (2012) Xd li dSng ttwi hdu cor va njtor trong nddc thii chan nufli Ipn bfing phucng phfip SBR: Anh hudng ciia chfi df v | n hSnti vii <i If giua cacbon hOu co vfi nllo. Tgp chl Khoa hoc vfi C6ng nghfi 50(2B): 153 - 1 6 1 .
3. Process Biochemistry. 4 1 :
SIMULTANEOUS ORGANIC AND NITROGEN REMOVAL FROM PIGGERY WASTEWATER B_YSBR.PRp,C_ESS:, EFFECTS OF FEEDING MODE- •
Phan Do Hung", Pham Thi Hai Thinh, Tran Thi Thu Lan
Institute of Envimnmental Technology, Vietnam Academy of Science and Technology
SUIVIiVURY
Simultaneous removal of organic and nitrogen matters from piggery wastewater by Sequencing Batch Reactor (SBR) process integrated widi double anoxic - oxic cycles and two-step feeding was investigated. Anaerobically digested piggery wastewater was fcd stepwise into the reactor during the anoxic stages witii ttir«e differmt feeding ratios (ratio of wastewater volume of die first feedmg to the totd feeding voluine in each batch) of 1/2,2/3 and 3/4. Effects of these ratios on remoVal'of chemical oxygen demand (COD), ammonium and total nitrogen (T-N) were expemnenlally determined and compared with fliose obtained in die case of single feeding mode Theoretical T-N removal efOciencies were also described and compared with the experimental ones. The results indicated that step feeding is a means for enhancing T-N rcmovaL It was also shown that when increasing the feeding ratio, T-N removal efficiency increased in the first ustaoce, however then decreased when the ratio reaching a given value Experimemal T-N removal eEBcicocies at diree investigated feeding ratios were raiber h i ^ in irfiich the highest was obtained at the ratio of 2/3, in the range of 85 - 90 %. The experioiencal T-N removal eSciencies at the low feeding ratios of 1/2 and 2/3 were in the same level wiih die theoretical ones. COD removal efficitticies in two-step feeding mode were also rather high, 85 - 90 % at die ratio of 2/3, close to that obtained in the single feeding mode. High values of COD and T-N loads were also achieved, 0.6 ± 0.3 kg-COD m*'-day'' and 0 16 ±0.06 kg-Nm"'-day'', respectively.
Keywords: Piggery wastewater, SBR, Simultaneous orgamc and nitrogen removal. Step feeding
•>luthor/brcorr»s^)ondence:Tel +64-0912 043 387, email [email protected]
