KHOA HOC SINH VIEN
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Nghien cuu hieu qua xir ly nuvc thai sinh hoat trong be phan ung sinh hoc
ung dung vat lieu bam dinh lam tir cay tre
Tom tat
Nghien cuu t h y c hien tren mo hinh aeroten- lang the tich V= 12,5 1 quy mo phong thi nghiem co he gia t h i vi sinh bang vat lieu tre d a t ngap nu'O'c. Nu-d^c thai thi nghiem co dSu vao BOD^=450 mg/1; Vat lieu b a m dinh tre duwc che tao chuan hoa t h a n h khdi. Ket q u a thi nghiem cho thay k h a nang b a m dinh tot ciia vi sinh vat len b l mat gia the. Hieu suSt xw ly theo BOD d a t t r e n 9 0 . % sau 3 h XU" ly flat tieu chu§n loai B xa r a ngudn.
De dat tieu c h u i n loai A, thcri gian xu* ly can Id^n hoTi 6h. Hieu suSt loai bo NH4+, NO3- d a t durac chirng to cac qua trinh nhir nitorat hoa, khii- nito-rat, a n n a m o x xay ra ddng thoi vdi qua trinh loai bo BOD m a khong c4n phai bd sung them chat dinh dirotig cung nhir tao cac d i l u kien dac biet ( y i m khi, t h i l u khQ cho cong t r i n h .
Abstract:
A study was carried out in aerotion tank -clarifier model with volume 12,51 working with submerged attached media made from bamboo tree. The attached media made from bamboo tree. Raw wastewater taken directly from city sewage collector was used for the study.
Experiment has been carried out for more than 4 months in two regime: (i) continues flow and (ii) batch regime.
Results of the study showed that activated sludge was fixed so well on suface of bamboo media bloc and got the
value of 27,8 g/m2 or 12,5 kg/m3. BOD removal effect is more than 90% within 3 hours of treatment in the batch
regime and treated water meets B category of Vietnam discharge standard QCVN 14:2008/BTNMT. To get A category of the Vietnam wastewater discharge standard the
time of treament needs to be extend to 6 hours. The fact that effect of nitrogent removal was at hight level without additional nutrients could be explained by all reaction of nitrification, denitrification and anammox procceses happened together inside attached, basic requirements of structural steel frames under seismic.
7'iS'. Trdn Thanh San
Khoa Ky thuat ha tdng vd Moi truang Do thi DT: 0904 716 975
Nguyen The Thdnh
Sinh vien Khoa Ky thuat ha tdng vd Moi truang Do thi
TS. Tran Thanh San Nguyen The Thanh
1. IVId'dau:
Ngay nay, cac cdng trinh XLP ly nude thai sinh hoc cd SLP dung vat lieu bam dinh dugc phat trien rong rai nhd hieu qua XLP ly, dp on dinh va it phat sinh bun du. Cdng nghe vat lieu phat trien nen gia t h i bam dinh cung da dang. Phin Idn chung dugc lam tCp vat lieu chit deo, composite cd gia thanh cao. Trong nghien cdu, viec tim kilm cac vat lieu mdi than thien mdi trudng, cd gia thanh ha de thay t h i cho vat lieu chit lam gia the bam dinh la mdt hudng ma cac nha khoa hoc dang quan tam. Cay tre, mot loai cay pho biln d Viet Nam thu'dng dugc dung lam vat lieu xay dyng truyen thing dugc nhdm nghien cuu quan tam. Thyc t l cho thiy cay tre tuai ngam trong nu'dc lau ngay vin dam bao dugc do bin ca ly. Tu cay tre cd the lam dugc gia t h i bam dinh do b l mat vat lieu phat trien va kha nang tao thanh cac bloc vat lieu b l tri trong nu'dc thai. Mot s l tong quan cho thay vat lieu tre cung da dugc nghien cuu lam gia t h i bam dinh cho XLP ly nude thai d Nam My (Bolovia, Venezuela). Tai Viet Nam, cac cdng trinh nghien CLPU SLP dung cay tre cho cdng trinh xu ly nude thai cdn ban chi [3].
Cac cdng trinh XLP ly sinh hoc bam dinh dugc hieu nhu cac loai be loc sinh hoc (biophin) cd bo tri gia t h i bam dinh khdng ngap nude hoac ngap nude. Trong mot $6 tai lieu cdn cd the goi la be phan Cpng sinh hoc va dugc duy tri cac chi do d p d-xi khac nhau tijy theo cdng nghe XLP ly. Tai Viet Nam, cac vat lieu bam dinh thu'dng dugc SLP dung cho be loc sinh hoc nhy sdi cudi, da dam, keramzit (trong lugng rieng: 500-1000 kg/
m^, dien tich rieng 50-100 m^/m^vll, do ring 40-50%), va cac vat lieu tong hgp tCp PVC, polystyrene, PE nhe ban, cd do ring Idn han (trong iLpgng rieng 12-140 kg/m^, dien tich rieng tCp din 450 m^/m^vll, do ring 90-97%).
Cac loai vat lieu nay cd b l mat phat triln tao dilu kien cho vi sinh vat bam dinh vao, tao sinh khoi trong b l xu ly. Nude thai sinh hoat mang chit huu ca (BOD) la ngudn thuc an cho vi sinh vat. Vi sinh vat "an" chit huu ca la lam sach nude. Vat lieu chit deo kha da dang cd t i l l d dang hat, dang lyai, dang sgi, t i m vai mIm, dang vdng, Ing hoac dang dan thanh qua clu nhd. Y tu'dng dygc hinh thanh la SLP dung vat lieu bam dinh ty cay tre; Chi
72
TAP CHI KHOA HOC K I E N TRUC X A Y DUUGs-=t=
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Hinh 1 . Kich tbu'dc mo hinh thu'c nghiem
i
Hinh 2. Khdi gia the bam dinh lam tu' tre tu'di tao thanh nhung khIi vat lieu bam dinh bang each k i t
hgp cac t i m dan cd do r i n g phu hgp d l b l tri ngap nude trong cdng trinh XLP ly hao khi d l thay the gia t h i bam dinh truyin thing khac.
2. Vat lieu va phu'ang phap.
2.1. Xay dung mo hinh thi/c nghiem.
Md hinh thyc nghiem dugc xay dyng tCp md hinh thyc nghiem aeroten - l i n g bang thuy tinh h&u ca (Arcrilic) cua trudng Dai hoc Tong hgp Texas, My [1]. Kich thudc mo hinh nhu trong hinh ve 2.1 do b i n g cm. T h i tich vung phan ung la 0,012285m3; Tong t h i tich la 0,018135m3 Vat lieu bam dinh tre se dugc b l tri vao trong t h i tich vung phan u'ng.
2.2. Vat lieu bam dinh sinh hoc tu' cay tre.
Cac nghien CLPU cho t h i y cay tre dac tinh ca ly t i t va dugc pho b i l n lam vat lieu xay dyng (xem bang 2.2).
Bang 1 . Dac tru'ng tinh chat cd ly cua vat lieu tre.
Thdng s l Do am
Cudng do chju keo Cudng do chju nen Modul pha hoai Modul dan hoi Modul cung Do din dien He so d i n nhiet Cudng do b l mat TJ trong mat do Cudng dp npi lien ket
Gia trj 8%
29,54 35,3 59,26
3174 6066 0,22 0,64 9,47 (khd)
9,1 (am) 0,79 1,97 (khd)
1,73 (am)
Dan vj
% n/s.q.m n/s.q.m n/s.q.m n/s.q.m n/s.q.m watt/mt KJ/m,h,0C
n/s.q.m n/s.q.m Gm/CC n/s.q.m n/s.q.m Mdt s l yeu c l u khi lya chpn vat lieu tre.
. Dac tinh ca hpc: Vat lieu tre phai cd du cydng.dp, ve ca hoc, d l cd kha nang chiu ung s u i t do trong l y g n g ban
than, vdi dac trung ty le cudng dp trpng lugng cao, cd t h i thich hgp s u dung trong xay dyng, nd cd t h i tang dp b i n n l u dugc ngam dudi nude.
He s l d i n nhiet: He s l d i n nhiet cua tre t h i p . Gia trj trung binh la 0.64 kj/m.h.°C thupc tinh nay lam cho vat lieu tre la mdt vat lieu ly tudng.
Kich thudc on djnh: Trong c b l tao san phim, n l u hoan thien cdng nghe may ep ndng dac biet, XLP ly t i t nhit tinh c h i t vat ly cua tre, tiii vat lieu tre ung dung r l t t i t trong cac mdi trudng.
C h i tao khdi vat lieu bam dinh lam tCp tre.
Tir s l lieu do dac v l t h i tich lam viec cua vung phan ung sinh hpc nhdm nghien cuu tinh toan thilt k l khIi gia the bang tre tuai sao cho dat vCpa trong b l d l lam viec tot nhit.
KhIi gia t h i dugc ghep t u nhOng t i m cd A x B = 12x12 tao thanh 1 block dang hinh hop chu nhat cd kich thudc A X B X H = 12 x l 2 X 13,5 nhu md hinh 2.
- Ghep cac t i m tre da dan thanh 1 khdi dang hinh hop chu nhat khich thudc 12 x I2x 13,5 (cm). Dua khIi gia the vao trong b l phan ung sinh hpc, dat chim hoan toan trong nydc.
T h i tich khIi gia t h i V = 12x12x13,5 = 1944 cm^ = 0,002 m3
Trpng lugng khIi gia t h i : 0,5 kg.
Tl trpng t h i tich cua k h I i : 250 kg/m^
TT trpng the tich dac: 915,125 kg/m^
Tong dien tich t i l p xuc cua khIi gia the: S = 9011,38 (cm2) = 0,901138 (m2)
- Dien tich rieng khoi gia t h i : 450 m^/m^ VLL - Dp rdng khoi gia the: 72,7%
Ty le chilm t h i tich trong ngan phan ung: 16%.
2.3. Sa d l thyc nghiem vdi ddng chay lien tuc.
Muc dich thyc nghiem: Nghien cuu sa bp qua trinh khdi ddng, gia tang sinh khIi va hieu qua XLP ly nude thai
SO 15 - 2014 / ^
KHOA HOC & CONG NGHE
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Hinh 2.3. Sd dd thi nghiem dong lien tuc.
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1- Thung djnh lu^ng nuvfc thai 50 lit;
2- Van dieu l<hien;
3- Ong phan phoi nu^c thai thi nghiem;
4- Ngan phan Cmg sinh hoc;
5- Khdi gia the bam dinh;
6- Ngan ling; 7- 6ng phan phoi khi;
8- May sue khi;
9- Thung dung nuKrc sau xu'ly.
4- Ngan phan u'ng;
5- Khdi gia the bam dinh;
6- Ngan ling;
7- Ong phan phoi khi; 8- May sue khi;
Hinh 4. Sd do thi nghiem theo me.
cua b l phan ung sinh hpc vdi gia t h i tre.
Phuang phap tiln hanh: Nude thai dugc lly tir he thing thoat nude thanh phi dua vao b l djnh lugng 1 cd dung tich 50 lit. Van dieu khiln 2 dilu chinh luu lugng nude thai chay qua Ing phan phli 3 vao b l phan ung 4 cd b l tri gia th i sinh hpc tre 5. Khdng khi dugc cung d p cho b l phan ung bing may sue khi 8 qua he thing phan phoi 7 vao b l 4 d l dam bao ndng dp d-xi trong b l it nhit la 2 mg/l. Kiem soat nong dp o-xi dugc thyc hien bing may do d-xi hda tan FWMT- 09 - Ml (do nhanh). Thai gian XLP ly dugc xac djnh la 6 tilng vdi luu lugng Q = 2 lit nude thai /Ih. Hieu qua XLP ly sa bd dugc danh gia theo chi s l BOD va SS. Tiidi gian tao sinh khIi dau tien de quan sat la 3 tuIn tuc la md hinh lam viec nhu aeroten lang, sau dd dua khIi gia t h i tre vao. Khi sinh khIi on dmh tren b l
mat gia thi, chit iLpgng nydc ra on djnh theo quan sat thi tiln hanh do chit lygng nydc theo BOD va SS va danh gia mCpc dp XLP ly.
2.4. Nghien cCw dong hoc xCr ly niKfc thai bang thi nghiem theo me (tiep theo ngay sau khi nghien cCeu vai ddng chay lien tuc ket thuc).
Mlu nude thai dLpgc do vao be phan u'ng 4 vdi khoi gia the bam dinh sinh hpc bing tre 5 va dugc tiln hanh sue khi. Oxi d p cho be bang may sue khi 8 qua he thong phan phli 7 (xem hinh 3). Nong dp d-xi hda tan trong be phan ung dugc kilm soat trong b l bang thilt bj do tay phdng thi nghiem.
Bon thi nghiem theo me dugc tiln hanh vdi mdt mlu nude thai de so sanh va xay dyng ddng hpc. Thi nghiem
Bang 3. Ket qua thi nghiem theo me
N 1 2 3 4 5 6
Chi tieu phan tich nu'dc thai COD
BODS
Nita amon N-NH4+
Nitarit (N-N02-) Nitarat (N-N03-) Ting ham lugng chit la lung (TSSJ
Den vj mg/l mg/l mg/l mg/l mg/l mg/l
NT dau vao 520 450 43 8,1 416 1124
Nu'dc thai qua XLP ly vai tbo'i gian (tinh bang gid")
3(h) 87 42 4,7 1,1 28 65
4(h) 82,4 40,3 4,8 1,15
30 69
5(h) 81,1 38,0 4,21 1,06 31 72
6(h) 75,2 36,9 4,18 1,19 25 60
QCVN14:
2008/BTN- MT(Cot B)*
50 10 50 100
*QCVN 14: 2008/BTNMT(B): Quy chuin ky thuat quoc gia vi chit luxyng nuvc thai sinh hoat
/ A TAP CHi KHOA HOC K I E N TRUC - XAY DUNG
1 sue khi trong vdng 3h; thi nghiem 2 sue khi trong vdng 4h; Thi nghiem 3 trong vdng 5h va thi nghiem 4 trong vdng 6h. M l u nude dugc l l y sau XLP ly va mang di phan tich. Cac cbl s l phan tich la BOD, COD, NH4+, NO2-, NO3- Lugng sinh khIi ( bun bam dinh) dugc xac dinh bing each rCra each rCpa sach khdi gia t h i , lpc l l y sinh khoi va s l y khd d nhiet dp 105°C cho d i n khi khdi lugng on djnh va mang vao can.
Muc dich cua thi nghiem: xac djnh cac thdng s l ddng hoc cua qua trinh loai bd cac c h i t n I n BOD, COD, NH4+, NO2-, NO3- lam ca s d cho viec thilt k l cac cdng trinh x u ly sinh hpc cd gia the tre.
3. Ket qua va ban luan
3.1. Thi nghiem vai ddng lien tuc.
Sau 3 tuIn thi nghiem, bun boat tinh da hinh thanh cd mau nau sang. Khi ngOng sue khi bun se lang va dong thanh 01 Idp dudi day b l (xem hinh 5). Bun cd kha nang lang tit, p h i n Idn khoi lugng sau 15 pfiut da lang hit. Tuy nhien nude l i n g v i n chua thyc sy trong, cd m l u due, nguyen nhan dugc giai thich la tuoi bun cao trong he la lO-ng nen cac mang t l bao c h i t khd lang (3 tuIn).
Qua trinh nuoi d y la t y nhien trong mdi trudng nude thai l l y tryc t i l p tir he thing thoat nydc do vao sdng Td Ljch nen bijn boat tinh dugc chpn lpc se la nhung chung vi sinh phCj hgp vdi d i l u kien mdi tru'dng nude thai sinh hoat.
Tiln hanh du'a khdi gia the tre vao b l phan Cpng va sue khi. Sau mpt ngay dem, bun boat tinh da c l djnh hoan toan tren be mat vat lieu tre (xem hinh 6). Nu'dc trd nen trong. Tilp tuc thyc hien qua trinh XLP ly lien tuc trong vdng 4 thang. K i t qua quan sat cho t h i y nu'dc sau XLP ly ludn cd dp trong dat yeu c l u theo cam quan chdng td dp on djnh cua qua trinh XLP ly. LLPgng c h i t la ICpng trong nude sau XLP ly r l t it, nude trong. Trong thdi gian lam thi nghiem khdng thyc hien viec l l y bun d u cung nhu xac djnh lugng biJn bam dinh.
Thyc hien viec l l y m l u va phan tich c h i t iLpgng nude d l danh gia sa t)p iiieu qua cua qua trinh XLP ly d y g c thyc hien 1 thang mdt l i n . C h i t lu'gng nuac thai d i u vao va nude sau x y ly du'gc danh gia theo nIng dp chlt,hCpu cd BOD va c h i t la ldng de sa bp danh gia hieu qua xu'ly.
Cac phan tich du'gc thyc hien tai phdng thi;nghiem V i l n Kiln true Nhiet ddi, trudng Dai hpc Kiln true H9 Npi, K i t qua thi nghiem va x u ly dugc trinh bay trong bang 3.
Cd t h i nhan t h i y vdi thdi gian x u ly 6 tilng, c h i t lugng nude sau XLP ly theo ham lugng cac c h i t hOu ca BOD va c h i t la iLPng SS yeu c l u dat tieu chuin loai A theo qui pham QCVN 14:2011 ( BOD = 30 mg/l; SS=50mg/l). Hieu s u i t XLP ly dat trung binh 92% theo BOD va 90% theo SS.
Bang 2. Ket qua t h i nghiem dong lien tuc TT
1 2 3 4
Chi so dau vao BOD (mg/l)
350 380 330 400
SS (mg/l)
550 400 480 600
Chi so dau ra sau xiP ly BOD (mg/l)
28 27 24 31
SS (mg/l)
45 41 49 50
Hieu qua xu' ly'(%) theo BOD
92 92 93 92
SS 92 89 85 92
Chu thich
Thyc nghiem dugc t i l n hanh trong thdi gian dai 4 thang sau mpt thang phan tich 1 lin) chung td dp on djnh cua qua trinh. K i t qua XLP ly s l lieu cho t h i y kha nang XLP ly nude thai sinh boat b i n g he vi sinh bam dinh dat yeu c l u . Cd t h i t h i y cdng trinh XLP ly he vi sinh bam dinh (bun boat tinh bam dinh) thyc hien ddng thdi hai chuc nang (i) XLP ly sinh hpc cac c h i t huu ca va (ii) lpc ca hpc cac c h i t vd ca nhu SS.
3.2. Xac dinh cac thong so dong hoc qua trinh xCr ly bang thi nghiem theo me.
Ngay sau khi k i t thuc chudi thi nghiem vdi ddng chay lien tuc, thi nghiem theo me dugc t i l n hanh. Nude thai dugc l l y tryc tilp tCp dudng I n g thoat nude khu dd thj chay ra sdng Td lich. Ha Npi cd ndng dp BOD giao ddng d i n 500mg/l dugc do vao be phan ung cd khoi vat lieu lpc tre c l djnh sinh khIi. 4 thi nghiem theo me dugc t i l n hanh cho cac thdi gian 3h, 4h, 5h, 6h. Khdng khi dugc sue vao be vdi cudng dp giu cho ndng dp d-xi hda tan DO khoang 2 mg/l. M l u nude sau XLP ly dugc l l y ra dLpgc phan tich cho cac chi s l . K i t qua thyc nghiem dugc trinh bay trong bang 3.
K i t qua phan tich dugc XLP ly b i n g p h i n mem chuyen dung excell. Cac do thi bieu d i l n qua trinh loai bd COD (hinh 8), loai bd BOD5 (hinh 9), loai bd Nita amdn N-NH4+
(hinh 10); Nitarit N-NO2-, Nitarat N-NO3 va tong ham iLpgng c h i t r i n .
Cd t h i t h i y ty le BOD5/COD cua nude thai la dac trung cho nydc thai sinh boat (0,8). Ndng dp BOD khoang
SO 1 5 - 2 0 1 4
75
KHOA HOC & CONG NGHE
mg/l
mg/l
MO ' 4O0 3O0 200 too 1
0 1
- * - B O D
Hinh 7. SU thay ddi COD theo thdi gian xu" ly trong be phan u'ng
-TSS
Hinh 9. Su' thay doi TSS theo thdi gian xuT ly trong be phan u'ng.
Hinh 8. SiT thay doi BOD theo thdi gian xiT ly trong be phan u'ng.
Hinh 10. Hieu suat xu' ly E% theo (1) N-NH4+;
(2) NO2' va (3) N-NO3' trong be phan u'ng sinh hoc vat lieu t r e theo t h d i gian.
450mg/l d cd vdi ndng dp Nita amdn (N-NH4+) va Nitarat cao (qua trinh Nita rat hda xay ra) ban binh thudng chung td nude thai dac trung cua b l t y hoai. Ham lugng TSS
1124 mg/l la hai cao d l i vdi nude thai sinh boat.
Do thi hinh 7 cho t h i y 3h sau khi XLP ly, nong dp COD giam tCp xuIng 520mg/l xuIng 87mg/l, tuc la XLP ly 83,2%.
T u gid thLP 4 trd di COD giam khdng nhilu dat chi s l 75,2mg/l t u la khoang 85,5%.
Tuang ty nhu vay, dd thj hinh 8 cho t h i y xu t h i loai bd B0D5 xay ra manh trong 3 tilng d i u tien sau khi XLP ly (BOD5 giam tCp 450mg/l xuIng 40,3mg/l) tCPC la vao khoang 90,6% v l hieu suit. T u gid thCp 4 trd di, hieu s u i t XLP ly tang len khdng dang k l va chi dat 91,8% sau 6 gid.
D l thi hinh 9 cho t h i y sy thay doi cua tong ndng dp chit la iLPng (TSS) theo thdi gian XLP ly. Sy thay doi cua nong dp c h i t la ICpng TSS theo thdi gian cung cd xu t h i thay doi nhu nhu COD va BOD nhu d tren. Trong 3 gid d i u TSS giam tCp 1124mg/l xuIng 65mg/l dat hieu s u i t XCP ly 94,2% va khdng cd sy giam dang ke nao chi giao ddng trong khoang 60-70mg/l trong cac gid t i l p theo.
Cd t h i nhan t h i y sau 3 tilng XCP ly, ndng dp cac c h i t hu'u ca hda tan (BOD) va tong ham lygng c h i t la ICpng (TSS) giam manh, c h i t lugng nydc sau XCP ly dat tieu chuan Joai B, QCVN 14:2008. Cac thdng s l chung td rang be phan Cpng vat lieu bam dinh tre cd kha nang thyc hien 2 chuc nang lpc va XCP ly sinh hpc va cd toe dp oxi hda cac c h i t hu-u ca Idn. Theo k i t qua nghien cuu ddng lien tuc thi BOD <400mg/l c h i t lugng nude thai sau XCP ly cd the dat loai A sau 6h.
Nghien CCPU cac k i t qua loai bd cac hgp c h i t nita amdn, (N-NH4*), nitrit (N-NOj), va nitrat (N-NO3-) cho t h i y hieu qua XCP ly cac bgp c h i t nita cao, dat dat dugc ngay trong 3 tilng d i u vdi hieu x u l t tuang Cpng la 89,1%, 87,5% va 93,3% vdi ndng dp d i u ra dat yeu cau theo qui chuin cot B cua QCVN14:2009/BTNMT. Thdi gian XCP ly tang them cung khdng lam cho hieu s u i t XCP ly N-NH4+, N- NO2-, N- NO3- (xem hinh 10). Cd the nhan t h i y ring cac hgp c h i t nay dugc loai bd dong thdi cung vdi qua trinh loai bd BOD khi tai trpng hCpu ca len sinh khIi bun cdn cao:
1,608g BOD/1 g bun.ngd khac ban vdi cac cdng trinh loai bd N truyin thing AO, A 2 0 , Bradenpho, UCT d i u la cdng trinh cd cd tai trpng hu'u ca t h i p tir 0,05-0,2 kg BOD/kg bun.ngd [ Melcalf &Edy]. Qua trinh loai bd ddng thdi BOD, NH4+, NO2-, NO3- cd t h i giai thich bang cac qua trinh oxi hda c h i t hu'u ca, nitrification, denitrification, anamox xay ra ddng thdi trong Idp mang sinh hpc bam dinh tren vat lieu tre. Day la hien tygng phCPC tap, c i n cd nhCpng nghien
CCPU bo sung.
Tren ca sd k i t qua phan tich s l lieu cd the xac dinh dugc cac thdng s l ddng hpc XLP ly c h i t nen lam ca sd cho tinh toan thilt k l nhu' (1) tai trpng len t h i tich tCpc la lugng c h i t hu'u ca (kg BOD) ma kha nang Im^ vat lieu bam dinh tre (VLL) dugc c h u i n hda (cd dp ring la 27%, trpng lugng rieng 250 kg/m^ VLL, dien tich rieng 450m2/1m3VLL) trong thdi gian la 1 ngay dem cung nhu (2) t i c dp trung binh d-xi hda rieng tuc la lygng c h i t hu'u ca (BOD) du'gc 1 g bun x u ly trong mdt dan vj thd gian la 1 h. Ngoai ra tai trpng t h i tich cdn dugc tinh toan cho qua trinh lai bd N-NH4+ , N-NO^- va N-NO3- de tinh toan cho cac cdng trinh xu" ly triet de. Phyang phap tinh toan
76
TAP CHi KHOA HOC K I E N T R U C - X A Y D U U GK i t qua xac djnh iLPgng sinh khIi (bun bam dinh) cho thiy trong khdi vat lieu lpc tre cho t h i y cd 25 g bun tinh theo c h i t khd bam dinh len khIi vat lieu lpc thi nghiem cd tong dien tich b l mgt la S= 0,901 m^ tren t h i tich khIi vat lieu lpc la V=0,002m3 Nhu vay, lugng bun tren Im^ vat lieu tre la: 27,8g/m2vll, tren mdt m^ t h i tich: 12,5kg/m3.
Bang 4. Thong so dong hoc loai bd chat hij'u cd cua khdi vat lieu bam dinh tre
N 1 2
Thong so dong hoc loai bo BOD Toe dp o-xi hda rieng trung binh, p
Tai trpng t h i tich cua vat lieu lpc, q
Dan vi mg BOD /g
bun.h Kg B0D/m3
VLL.ngd
Gia trj 0,067 20,07
Vi thdi d i l m 3h la d i l m ma hieu s u i t xir ly Idn nhit, sau dd hieu s u i t XCP ly tang len khdng dang ke nen cac thdng s l ddng hpc nhu" t i e dp o-xi hda rieng (mg BOD/g bun.h), tai trpng t h i tich (kg BOD/m^VLL.ngd) se dugc xac djnh d l lam ca s d thilt k l tinh toan la cac gia tri trung binh trong thdi gian 3h. Do d i l u kien nghien CLPU cho de tai sinh vien cd han nen khdng t h i thyc hien dugc nhilu thi nghiem va thyc hien a cac bu'dc thdi gian nhd han nen tam coi thdi gian 3h XCP ly la t l i uu. Se la t i t ban va cd dp tin cay cao n l u dLpgc thyc hien phan tich nhilu l i n . Kit qua XCP ly s l lieu dugc trinh bay trong bang 4;
Bang 5. Thong so dong hoc loai bd cac hdp chat Nitd cua khdi vat lieu bam dinh tre.
N Thong so dong hoc Dan vj Gia trj Loai bd N-NH4*
1 2
Toe dp o-xi hda rieng trung binh, p
Tai trpng the tich cua vat lieu lpc, q
mg N-NH4+ /g bun.h KgN-NH4+/
m^vll.ngd
6.28 1.88 Loai bd N-NO3-
1 2
Tdc dp o-xi hda rieng trung binh, p
Tai trpng t h i tich cua vat lieu lpc, q
mg N-NO3- /g bun.h KgN-N03-/m3
vll.ngd
63.63 19.09
XLP ly triet d l de loai bd cac hgp c h i t N, cac thdng s l v l t i c dp d-xi hda nita amon, NH4+, hay t i c dp khCp nitrat NO3-, cac thdng s l v l tai trpng cac c h i t tren len vat lieu lpc cd t h i dugc SLP dung d l tinh toan. Tuang t y each t i l p can xac djnh thdng s l BOD, cac thdng s l v l viec loai bd N dugc tinh toan K i t qua XCP ly s l lieu v l loai bd cac hgp c h i t cua N dugc trinh bay trong bang 5.
K i t luan va kien nghj
K i t qua nghien CCPU cho chung ta cac thdng so ca ban de thilt k l b l phan Cpng sinh hpc gia t h i tre phu hgp vdi cac day chuyin cdng nghe cdng s u i t vCpa va nhd tai nhCpng nai khdng cd he thing thoat nude tap trung hoac CO he thing thoat nude phan tan. Cac thdng s l chinh la t i e dp o-xi hda rieng trung binh theo BOD la 0,067mg BOD/g bun.h; tai trpng t h i tich theo BOD la q=0,815 kgBOD/m^vll.ngd:
ChCpng minh dugc bang thyc nghiem tinh kha thi khi SU" dung b l phan Cpng sinh hpc ngap nude vdi gia t h i bam dinh tre. Thdi gian xir ly la 3h dat tieu chuin loai B theo QCVN 14:2008; D l dat dugc loai A, thdi gian XCP ly d n tang len 6h. Ndng dp c h i t hu'u ca nude thai sinh boat d i u vao kiln nghj la 300mg BOD/I.
Bang thyc nghiem chCpng minh dugc cac qua trinh XLP ly c h i t hCpu ca (BOD), nita amdn (NH4+), nitarit (NO2- ), va nitarat (NO3-) xay ra d i n g thdi trong b l phan Cpng va dat hieu suit XLP ly cao khoang ban 90% ma khdng d n bo sung c h i t dinh du'dng nhu trong cac day chuyin truyin thing loai bd N nhu AO, AgO, Bradenpho, UTC.
Cac cdng trinh truyin thing d i u la cac cdng trinh cd tai trpng hCpu ca thip, trong khi do b l phan Cpng sinh hpc gia t h i tre lam viec d c b l dp tai trpng iiu'u ca cao.
Tren ca sd k i t qua nghien CCPU vdi so l i n phan tich thyc nghiem cd han, cd t h i sa bp thilt k l va dua vao Cpng dung cac tram cdng s u i t nhd dang pilot cd vat lieu tre thCr nghiem d l khao sat dp tin cay va I n djnh trong thdi gian dai. Ngoai ra, de tim dugc ban c h i t qua trinh loai bd cac hgp c h i t N d i n g thdi thdi trong b l phan Cpng sinh hpc ngap nude vdi gia t h i tre d n cd nhu'ng nghien CCPU ca ban bo sung.
Tai lieu t h a m khao
/. Tom D Renolds. Unit operation andproccesses in
environmental engineering. Brooks/Cole Engineering Division.
Wadsworth. Inc, 1982.
2. Melcalf &Edy. Water Engineering. Treatment Disposal Reuse.
McGraw- Hill International Editions, 2003.
3. Trdn VTnh Dieu. Application ofPP-bamboo composite for preparation of attached-growth media used in waste water treatment. Trung tdm nghien cuu vgt lieu Polymer, 5/2009.[
http://dspace.hui.edu.vn:8080/dspace/handle/123456789/3643.
14h00 ngay 9-5-2014]
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Phan bien: TS. Nguyen Van Nam Trinh Xudn Lai. Gido trinh tinh todn xu ly thiet ke cdc cong trinh xir ly nuac thdi. Nhd xudt bdn Xdy Dung, 2008.
Hodng Van Hue. Xu ly nuac thdi. Nhd xudt bdn Khoa hoc Ky thudt, 2002.
TCVN 7957:2008 - Tieu chudn Thiit ki Thodt nude - Mang luai ben ngoai vd cong trinh.
QCVN 14:2008/BTNMT- Quy chudn ky thudt quSc gia vi nuac thdi sinh hoat.
SO 1 5 - 2 0 1 4
