KHOA HOC & CONG NGHE
G^r^rg^ c\o.^
Uhg dung phan mem GPS-X
trong quan ly qua trinh len men yem khi
ThS. Nguyen Thi My Hanh
Tom tat
Nuo'c thai sinh hoat ciing vol rac thai hij-u co", thij-c an thu-a tir cac nha hang va dac biet la bun tir cac hi t y hoai la cac ngudn chSt thai Idn trong do thi. Hien nay, cac loai chat thai nay dang ngay ngay du-oc xa ra moi tru-crng vol khoi lu'ong Ion va chi du-crc xu- ly mot phan rat nho, do do gay 6 nhilm moi tru-ong nghiem trong.
Quan ly cac loai chSt thai nay dang la \kn de ciia hSu hgt cac do thi. Mot hiroTig tilp can moi trong thtri gian gSn day la quan ly tong hop, thu gom va xu- ly nu'O'c thai, chSt thai ran cua tirng khu vye vao tram xu* ly tap trung. Chat thai hCru CO" trong khu vye se du-yc xir ly nho" qua trinh len men yem khi, tao ra san pham khi sinh
hoc phue vu cho viec cSp phat dien, bun thai du'oc tan dung lam phan bon. Nghien ciru li'ng dung phan mem GPS-X nham muc dich xac dinh du-yc ti le phoi tron eae nguon thai chat huu CO trong do thi hyp ly sao cho hieu suSt thu khi sinh hoc la cao nhat, tir do c6 the lam nguon
cung cSp nhien lieu.
Abstract
Waste water with organic waste, food scraps from restaurants and especially sludge from septic tanks is the major source of waste in urban areas. Currently, this waste on the date is discharged into the environment in large quantities and can only handle a very small, thus causing serious environmental pollution. Management of this waste is a problem for most urban areas. A new approach in recent times is the integrated management,
wastewater collection and treatment, solid waste of each area to the centralized treatment plant. Regional organic waste will be treated by anaerobic fermentation, creating products of biogas for electricity supply, sewage sludge utilized as fertilizer. Research and using software GPS-X aim to determine the mixing ratio of organic waste in urban reasonable so that the biogas collection efficiency is the highest, which can be ftiel.
ThS. Nguyin Thi My Hanh Bo mon Cap nuac - Khoa Do thi DT: 01682172093
1. Thye trang va phu'O'ng hu'O'ng tiep can trong quan ly thu gom va xu' ly chat thai htPu co" a cac do thj cua Viet Nam
Cac nguIn ehu ylu phat sinh ra rae d6 thj bao gIm:
TLP cac khu dan CLP (rac sinh hoat) - TLP cae trung tam thLPang mai, TLP cae e6ng sa, trLPO'ng hpc, e6ng trinh e6ng epng, - Tir eae hoat dpng e6ng nghiep; - TLP cac hoat dpng xay dLPng d6 thj; TCP eae tram XLP ly nLPac thai va tO eae du'ang Ing thoat nu'O'e eua thanh ph6.
Rae dLpge eh6n lip chilm khoang 15% ting iLpgng rac du'ge thai ra. Phln ehu ylu rac thai ran dang virt bCpa bai hoac chit ding khap nai. Rac htpu ca khong XLP ly va cae bai rae khong hgp ve sinh se phat ra iLpgng khi CO2 rat lan.
Nu'O'e thai d6 thj eua Viet Nam cung tin tai nhilu bit cap. He thing thoat nu'ac va ve sinh d6 thj cua Viet Nam chu ylu dIu la he thing thoat nu'O'e ehung.
PhLPang phap lam sach sa bp nu'O'e thai pho biln niilt hien nay a eae do thj van la cac b l tLP hoai dat du'ai nIn nha, tCp do nu'O'e thai du'ge xa trye tilp ra moi trLPang. 0 thanh phi Ha npi, hang nam eo khoang 250 t i n phan biJn b l phit dLpge thu gom tCp cac b l tLP hoai.
DLP an thoat nLPae Ha npi giai doan 1 (1995-2005) va giai doan 2 (2006-2010) cung mo'i chi c6 dilu kien tap trung vao giai quylt ung ngap va bLPO-c dIu XLP ly nu'ac thai eho thanh phi Ha npi. Vin d l XLP ly bun thai thu gom dLPge tCp mang iLPai thoat nLPae, cung nhu"
phan bun b l phIt tCp cac be ty hoai vin eon bo ngo.
NhLP vay, eae d6 thj Viet Nam dang phai chiu mot ganh nang rlt lan v l chit thai hO'u ea vo'i m6i tru'O'ng.
Vin d l giai quylt chit thai huu ca tra nen eIn thiet han bao gio' hilt nham bao ve m6i tru'ang va phat trien bin viJng trong tLPang lai.
Hien nay, cac d6 thj Viet Nam dang ap dung mo hinh quan ly chit thai dpe lap, tCpc la nLPae thai va rac thai dLpge quan ly rieng. Viec quan ly nay do khong tan dung du'ge nguIn N, P eIn thilt cho cay trIng c6 san trong nuo'c thai va nguon nang lugng tu rac thai kh6ng nhij-ng gay lang phi ma con anh huo'ng to'i m5i truo'ng.
Nhung vo'i tinh hinh hien nay, viee thu gom va XLP ly tap trung chat thai eua eae d6 thj lan la kh6 kha thi, lai lang phi. Viee to chCpc thu gom va XLP ly phan tan chit thai tai cac hp gia dinh, c6ng sa cung khong t h i kha thi do khong c6 dilu kien ve dat dai, phuang tien... Do do, phuang thCpc XLP ly chit thai theo m6 hinh ban tap trung to ra eo nhilu uu diem: tho'i gian thu gom va XLP ly ngIn, chi phi van chuyen rae thai giam, dp tin eay tang cao.
36
TAP CHi KHOA HOC KIEN TRUC XAY DUNGmil sinh hoc
nuocdungxi^ly'^ ^ b u n
» »hi ga sinh hoc
ffif^den Quaxuly
L .
hoat dong nho nSnj luong tai smh% \
cac khu nha hiin tai xjycu
Hinh 1. Mo hinh xu' ly chat thai cua trung tam SDC
Trong phuang thCpc thu gom ban tap trung, rae thai sinh hoat, bun be tu hoai va bun eing he thing thoat nuac se duge XLP ly tong hgp dam bao chit lugng dIu ra theo yeu elu. Giai phap e6ng trinh XLP ly nuac va rae thai CO t h i duge thuc hien theo each hgp khIi, nhilu ting, nham giam yeu clu dien tich va chi phi hgp ly, trong khi van tap trung duge mpt lugng lan nuo'c va rac thai de XLP ly va tai SLP dung, cung nhu tan thu nang lugng lim nhien lieu va ding tho'i giam thieu chi phi van chuyin chit thai.
2. U'ng dung GPS-X de mo phong qua trinh len men yem khi
Ca SO' toan hpc d l thilt lap m6 hinh quan ly bun can duge SLP dung 6' day la ma tran Peterson. Mpt trong nh&ng c6ng eu toan hpc duge ap dung, vCpa dam bao tinh chinh xac cua m6 hinh, vCpa dam bao su dan gian, de hilu cho nguo'i SLP dung.Trong thi nghiem v l qua trinh len men yim khi, ma tran Petersen duge thilt lap dua tren sy tang truang va suy giam sinh khIi eua vi sinh vat trong m6i truo'ng yIm khi:
- Buae dIu tien thiet lap ma tran la xac djnh eae qua trinh sinh hpc xay ra trong m6 hinh. Qua trinh len men yIm khi thong thuo'ng diln ra qua 4 giai doan sau: (sa d l hinh 2)
Buo'c thu hai trien khai ma tran la xac djnh cae thanh phln tham gia vao qua trinh nhu cac nguIn ea chit; cac loai vi sinh vat. Day la nhung thanh phln quan trpng, sy thay doi ham lugng eua ehung quylt djnh diln biln cua ca thi nghiem. Cac thanh phln khae se duge xac djnh trong qua trinh tinh toan dya vao mli quan he chi phli lin nhau cua cae thong s l . Su thay doi sinh khIi vi sinh vat duge the hien qua eae sa d l khoi sau (xem hinh 3.3)'
Giai doan thiiy phar
Qai doan leu men axit
Hop chat hiiu cff plian tut lugmg Ion (gliixit, protein, lipit...)
Chat hiJu co phan td luong nho (duomg, axitamin, axit bee.)
Len men axit hum co va Cac chat tnmg tinh
Axit propionic, rugru, andehit, axeton
Cac chat Idii C02,H2,NH3,H2
Axetic hoa Axit axetic
Decacboxyl hoa
Len men tao metan
Khu CO, 8H-
CH4 + CO2
Hinh 2. Qua trinh len men yem khi thong thu'dng dien ra qua 4 giai doan
SO 13-2013
'^7
KHOA HOC & CONG NGHE
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Hinh 3 . 1 . Qua trinh thuy phan cua Hinh 3.2. Qua trinh len men axit Hinh 3.3. Qua t r i n h phan huy cua cac loaiv cac hdp chat hCi'u cd va len men me tan sinh vat
Hinh 3. Sd do khoi cac qua trinh dien ra trong dieu kien len men yem k h i
m^) m^)
Trong do:
xzg:chlt hO'u ca d l thuy phan tCp bun be t y hoai (gCGD/m^)
xzo: chit huu ca d l thuy phan tCp thuc an thCpa (gCOD/
xzj: chit hCpu ea d l thuy phan tCp rae huu ea (gCOD/
sf: ca c h i t eho vi khuin len men axit (gCOD/m^) xzd: vi khuIn len men axit (gCOD/m^)
sif: ea c h i t cho vi khuIn len men me tan (gCOD/m^) xze: vi khuIn len men me tan (gCOD/m^)
xzm: khi me tan duge tao thanh (gCOD/m^)
xzf: vi khuan hilu khi eo trong bun b l t u hoai (gCOD/
m^) m3)
xzh: vi khuan hilu khi c6 trong thue an thCpa (gCOD/
xzi: vi khuIn hilu khi eo trong rae thai huu ea (gCOD/
m^)
xu:hgp c h i t kh6ng phan huy sinh hpc trong bCin da len men (gCOD/m^)
Cae gia trj 1; 1/yae; 1/ym; fu la ti le eua ea c h i t ban d I u va san phIm tao thanh trong eae qua trinh neu tren.
Qua ba sa d l tren ta eo t h i thIy ro eae qua trinh sinh hoa t r o n g d i l u kien len men I m . Ban d I u cac hgp c h i t hOu ca d l phan huy trong bun b l t y hoai, trong thCpc an thCpa, trong rae thai huu ea se duge thuy phan trong mpt thai gian nhlt djnh d l tao ra nguIn ea c h i t (nguIn thue an) eho vi khuan len men axit trong qua trinh axit hoa.
Trong qua trinh axit hoa, vi khuan len men axit se SLP dung nguIn thCpc an tren de tao nen sinh khIi eho chinh minh va tao ra mpt nguon ea c h i t mo'i dung eho qua trinh me tan hoa. 6" qua trinh me tan hoa, vi khuan me tan lai SLP dung nguIn thuc an vi>a duge tao ra a qua trinh axit hoa d l tao nen sinh khIi eho minh va tao ra khi CH4. Song
song vai cac qua trinh tren la qua trinh t y phan huy cua cac vi sinh vat co trong m6i truo'ng len men y I m khi de tao ra nguIn ca c h i t gilng vai c h i t huu ea eua bun betii hoai va mpt loai hgp c h i t kh6ng phan huy sinh hpc. Cac qua trinh tren c u nhu vay d i l n ra lien tue.
BUO'C thLP ba hoan thien ma tran ia xac djnh cac b i l u thue dpng lye va phuang trinh t i e dp, bilu diln sif thay doi cua sinh khIi vi sinh vat theo ham lugng ea chit.
Tang truang sinh khoi duge bieu thj bang phuang trinh eua Monod:
>" = y"maxX
C
- X
V^.+C,,
K.
v^.+C.y
Qua trinh thuy phan cae hgp c h i t cham phan huy sinh hpc duge bilu dien bang e6ng thCpc Contois do thi nghiem duge t i l n hanh theo me, lugng ea c h i t bj giai han va co sy tham gia eua nhilu loai vi khuIn khae nhau nhLP vi khuan hilu khi tuy tien trong bCin be t u hoai, vi khuan hilu khi tuy tien trong thCpc an thCpa da len men, vi khuan hilu khi tuy tien trong rae thai huu ea da len men va vi khuan len men axit.
TLP do ta xay dung 6wgc ma tran Peterson ap dung eho m6 hinh len men y I m khi
3. Thi nghiem ve qua trinh len men yem khi 3.1. Muc dich va phuxyng phap thi nghiem
M6 phong duge qua trinh x u ly rae huu ea (rae cha, rac nha hang) va bun be t y hoai.
Xac dinh duge ti le p h l i tron t l i uu n h l t giOa ba nguIn ea c h i t (bun b l t y hoai, rae huu chg, rac nha hang). Tii do xac djnh thai gian toi uu n h l t eho qua trinh len men y I m khi cua hon hgp da p h l i tron.
NguIn nguyen lieu dwgc l l y tCp thi nghiem cua dy an SemiSan:
- BCin b l t y hoai: diygc lay ti> b l t y hoai eua khu ky tue xa Dai hpc Xay dyng.
ThLPc an thCpa: dyrgc l l y tCp cac quan cam binh dan
38
TAP CHi KHOA HOC K I E N T R U C - X A Y DUTJGTong t h i tich eua hon hgp la 1 m^
Bang 1. Ti le phoi tron cua cac binh thi nghiem Binh thi nghiem
Biin be tip hoai (1)
Rac nha hang (thu'c an thipa) (1) Rac chg* (rac hO'u co") (1)
1 400 300 300
2 500 200 300
3 750 100 150
4 1000
0 0
Bang 2. Ham lu'dng cac thanh pKan chinh co trong biin be W hoai va rac hO'u cd
Binh t h i nghiem BCin be tip hoai (1)
Rac nha hang (thu'c an thira) (1) Rac c h a (rac hO'u ca) (1)
COD (mg/l) 54755 672000
110400
BOD (mg/l)
0 45000 65000
T-P (mg/l) 863.60 623.82 233.59
T-N (mg/l) 1751.30
233.59 4974.00
N02 (mg/l)
0.00 218.90 208.30
N03 (mg/l) 72.70 226.78 220.30 3.2 Ket qua thi nghiem
Kit qua thi nghiem duge the hien tren eae bang a phu lue va d l thi eua bin thi nghiem nhu sau:
Hinh 4.1. Do thj bieu dien ket qua thi nghiem binh 1
g
5
Hinh 4.2. Do thi bieu dien ket qua thi nghiem binh 2
0)
\ .
4.0 SO KHaysl
Hinh 4.3. Do thj bieu diln ket qua thi nghiem binh 3
i \
2,0 3,0 t[ilaysl
Hinh 4.4. Do thj bleu dien ket qua thi nghiem binh 4
SO 13 2013 / s Q
KHOA HOC & CONG NGHE
12.0 1B.0 I [<i»y«l
Hinh 5.1. Ket qua thi nghiem cua binh 3 vdl thdl gian 30 ngay
1-
ra
1 I 8-
tldays)
Hinh 5.2. Ket qua thi nghiem cua binh 3 vdl thdl gian 45 ngay
i
1
o
t Idaysl
Hinh gian
5.3. Ket qua thi nghiem cua binh 3 vdi thdl 60 ngay
Kit qua duang MPR (Methan Production Rate- d l thj tie dp tao thanh khi Metan) eua 4 binh eo dang tuang ty nhau, Chung to ca ehl XLP ly sinh hpc a ea 4 binh gilng nhau va dae trung eho su phan huy sinh hpc do tron lin 3 nguIn ea chit c6 ehl dp dpng hpc khac nhau. Tuy nhien, tie dp sinh truang eua vi sinh vat trong mli binh cung khac nhau: Tie dp nay tang din theo thCp ty binh 1, binh 2, binh 4, binh 3. Dilu nay eo t h i ly giai do ning dp co chit 6' mli binh thay doi cung nhu s l lugng vi sinh vat len men metan va len men axit theo lugng bun duge cung clp cho mli binh la khae nhau.
TLP kit qua eua cac thi nghiem tren ta thIy duge:
Lugng khi tao thanh sau 5 ngay eua eae binh l§n lugt nhu sau:
+ Binh 1: 263.35 I; Binh 2: 262.41 + Binh 3: 251.575 I; Binh 4: 246.485 I
Tie dp tao khi cung nhu ehl dp tao khi duge the hien tren eae d l thj (hinh 4.1; hinh 4.2; hinh 4.3; hinh 4.4).
Ti le COD: ting N: tong P cua mli binh la:
+ Binh 1: 426:4:1 ; Binh 2: 311:4:1 + Binh 3: 167:4:1 ; Binh 4: 63:2:1
- So sanh lya ehpn giua eae kit qua thi nghiem thi ta thIy vai ti le phli tron a binh thu 3 cho kit qua tit nhlt (tic dp tao khi nhanh nhlt, ti le COD: ting N: tong P la 167:4:1 phu hgp nhlt vo'i ly thuylt la 150:5:1)
Nhu vay, ti le phli tron hgp ly nhlt 6vfgc de xult a day la: Bun b l tu hoai: Rae chg : thue an thCpa = 750 : 150:
100 = 7.5: 1.5: 1
TLP ti le phli tron t i t nhlt ta di xac djnh tho'i gian tli u'u nhlt eho ti le nay. Vai eae mCpc tho'i gian la 30 ngay, 45 ngay va 60 ngay. Kit qua thi nghiem duge the hien trong cac bang va bilu d l sau: (Hinh 5.1, Hinii 5.2, Hinh 5.3)
D6 thj kit qua thi nghiem eua binh 3 trong cac thai gian 30 ngay, 45 ngay, 60 ngay eho thIy tho'i gian thi nghiem 30 ngay se eho hieu qua tao thanh khi CH4 la t i t nhlt.
4. Ket luan, de xuat va kien nghj
TLP nhung nguIn ea chit th6ng qua qua trinh thi nghiem va phan tich ta tim ra duge s l lugng vi sinh v§t trong mpt dan vj the tich tuang Cpng vai tCpng loai ea chit.
Sau do ta tilp tue thi nghiem de lya chpn ti le phli trfin thanh phln ea chit nham dua ra kit qua t l i uu. Viee lya chpn 6iygc tiln hanh tren nhilu thi nghiem trpng cijng mpt dilu kien (pH, nhiet dp, dilu kien khuly tron) va khoang tho'i gian nhu nhau vai cac ti le phli trpn khac nliau. Trpng khpang tho-i gian nay ta phai lien tue thu thap s l lieu d l nham chinh xac hoa thi nghiem nhlt eo thi.
TLP nhung s l lieu do mai c6 the rut ra duge lugng khi tao thanh va tie dp tao thanh khi tren mli ti le piili trpn.
Tren ea so' do lya chpn duge ti le phli trpn t l i uu nliat (do la ti le phli trpn dat duge lugng khi lan nhlt va tic dp tap khi nhanh nhlt). Sau do vai ti le phli trpn t l i uu da ehpn duge lai tiln hanh thi nghiem vai cae khoang thai
(xem tiep trang 55)
