Hgi nghi Khoa hoc ky' niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Noi 10/2010<br />
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NGHIEN CLTU iTNG DUNG CONG NGHE HOA HOC<br />
• • •<br />
TRONG XLT LY 6 NHIEM VA BAO VE MOI TRUTOTVG<br />
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Pham Hong Hai<br />
Vien Hoa hgc cac hgp chat thien nhien; 18 - Hoang Quoc Viet, Ha Noi<br />
E- mail: hai.inpcfSjyahoo.com<br />
Tom tat:<br />
Cdng nghe mdi truorng lien quan chat che vdi cdc nganh khoa hoc cdng nghe<br />
khdc, trudc het Id hod hoc vd cdng nghe hod hoe. Cdc qud trinh vd thiet bi cdng<br />
nghe hod hoc Id ca sa khoa hoc quan trong trong viedinh todn cdc cdng trinh xic<br />
ly d nhiem vd bdo ve mdi truang.<br />
Md hinh hod todn hoc- phuang phdp nghien cicu hien dgi ciia cdng nghe hod<br />
hoc cd the duac sic dung cd hieu qud trong cdng nghe mdi tricdng.<br />
Han 15 ndm qua, Lien hiep KHSX Cdng nghe hod hoc (UCE) dd nghien cicu<br />
trien khai nhieu cdng trinh xic ly d nhiem bdo ve mdi truang cd ket qua nha nghien<br />
cicu, tinh todn cdc qud trinh thiet bi cdng nghe mdi truang theo cdc bdi ban cita<br />
cdng nghe hod hoc.<br />
Abstract:<br />
Environmental technology is closely associated with other branches, firstly with<br />
chemistry and chemical technology. And processes and apparatuses of chemical<br />
technology are considered as important background in pollution control and<br />
environmental protection.<br />
Mathematical modelling - the modern research method of chemical technology<br />
can be used effectively in environmental technology.<br />
Over last 15 years the Union of scientific research and production on Chemical<br />
Engineering (UCE) has carried out successfully many waste treatment systems to<br />
environmental protection due to good application of chemical engineering<br />
knowledges in reseaching and calculating of proecesses and apparatuses of<br />
environmental technology.<br />
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L MO DAU<br />
Viet Nam dang a thai ky day manh CNH, HDH dat nuoc. De phat trien ben viing phai<br />
tien hanh cac boat dong bao ve moi truang. Nha nuoc ta tir nam 1994 da ban hanh Luat Bao<br />
ve moi truang ddu tien, nam 2005 Quoc hgi khoa XI lai thong qua Luat Bao ve moi truong<br />
moi thay thi luat do va hien dang c6 hieu luc. Dang ta cung da ra Nghi quyet so 41-NQ/TW<br />
khoa IX vl bao ve moi tru6ng khang dinh "Bdo ve mdi truang Id mdt trong nhirng vdn de<br />
sdng cdn ciia nhdn logi, vica la muc tieu viea Id mdt trong nhirng ndi dung ca bdn cua phdt<br />
Iriin bin virng, Id quyen lai vd nghia vu cua moi to chirc, moi gia dinh vd ciia mdi ngudi".<br />
Van minh nhan loai thai dai cong nghiep phat trien gan lien vai cugc each mang khoa hgc<br />
- ky thuat. Ngay nay cugc each mang nay da chuyen thanh each mang khoa hgc - cong nghe<br />
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Tieu ban: Moi truang va Nang lucmg ISBN: 978-604-913-013-7<br />
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\'6i thanh to cong nghe \ a >"eu cau giai quyet hang loat van de. trong do co yeu cau tiet kiem<br />
nang lugng. tai nguyen \"a bao \ e moi truong. can bang sinh thai.<br />
Truoc >eu cau bao \ e moi truong mot ngaah cong nghe mod da hinh thanh: cong nghe<br />
moi truong. Theo dinh nghTa ciia H.Pea^"\" (1985) "Cdng nghe mdi truang Id nganh cdng nghe<br />
lien quan den bao ve mdi trucnig khoi nhirng huy hogi tiem tdng do hogt ddng cua con ngudi.<br />
bao ve lodi ngircri khoi tdc ddng cua nhirng yeu to mdi truorng bdt lai vd cai thien chdt luang<br />
mdi truang vi sire khoe vd sir tdn tgi tdt ciia con ngudri" [1].<br />
Cong nghe m6i truong quan he chat che den cac nganh khoa hgc \"a cong nghe khac: hoa<br />
hgc. vat ly. sinh hgc. xay dung... Dac biet co the noi cong nghe moi truong truoc het la sir van<br />
dung cac qua trinh va thiet bi cong nghe hoa hgc de xu ly chat thai (ran. long, khi) \ a kiem<br />
soat 6 nhiem phuc xu cho muc dich bao \ e moi truong<br />
Bai \ iet na}' de cap den \an de nghien ciiu ling dung cong nghe hoa hgc trong xu ly 6<br />
nhiem \k bao \ e moi truang. neu len co so khoa hgc cua bg mon qua trinh thiet bi cong nghe<br />
hoa hoc. phuang phap nghien cim hien dai cua no \ a sir \'an dung trong cong nghe moi truang.<br />
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2. KHOA HOC \1 CAC QU.\ TRINH VA THIET BI CONG NGHE HOA HOC<br />
Cong nghe hoa hgc la mot nganh cong nghe gan vod san xuat cac loai hoa chat, rat da<br />
dang \a phiirc tap. "Cdc qua trinh vd thiet bi' Id khoa hoc dua tren ca sa nhimg dinh luat<br />
chung cua vdt ly vd Iiod hoc. ve ban chdt la ca sa ly luan cua nganh cdng nghe hod hoc. cho<br />
phep phdn tich vd tinh todn qud trinh. tim ra cdc thdng sd cd lai nhdt vd tinh todn thiit bi de<br />
thuc hien qud trinh.<br />
2.1 So liroc ve Ijch su phat trien<br />
Tir CO xua nguod ta da biet den cac qua trinh khac nhau nhu: Igc. co. chung cdt. sdv tu\<br />
nhien thiet bi su dung rat so dang. \'6d sir phat trien cua cong nghiep hoa chdt culi thi kv XVTII<br />
- dau the k\- XIX da xa>- ra \dec hoan thien thiet bi cho cac qua uinh da bilt \a xudt hien nhiing<br />
qua trinh rnod \ a i thiet bi moi. Dieu na>- lien quan den hai nganh san xudt duang \a rugu \ana.<br />
Xhimg thiet bi mod la thiet bi co dac chan khong. cot chung luyen. may ep Igc khuna ban. Cu6i<br />
the k}- XIX la cac thiet bi lam lanh gan \ 6d san xuat axit sulftiaric xa. cac chdt khi.<br />
Tu>- nhien do thieu ly luan \ e cac qua trinh xa phuong phap tinh thiit bi ma mot thai gian<br />
dai luon kh6 khan de dua nhung thiet bi tien bg. hieu qua hon vao san xudt. Do ^•ay sana the kv<br />
XX (1909 - Krupxky A.K; 1912 - Chisento I.A) nha kit qua cua viec ting kit kinh ngh"iem san<br />
xuat da hinh thanh nen ly thuyet cac qua trinh xa thiit bi. Bg mon khoa hgc moi niy lap nic<br />
dugc phat trien rat nhanh \-a dat dugc nhimg thanh urn dang ke gop phdn quan trgna \ao sir phat<br />
trien ciia nganh cong nghiep boa chat trong nen kinh t l thi gioi thi ky XX \ a hien nay.<br />
2.2 Phan loai cac qua trinh co ban cua cong nghe hoa hoc<br />
Cac qua trinh xa thiet bi chung cho nhiing nganh khac nhau ciia cong nghe hoa hgc dugc<br />
ggi la cdc qud trinh vd thiet bi ca ban [2.3].<br />
Cac qua trinh co ban cua cong nghe hoa hgc co thi dugc phan loai theo nhima ddu hieu<br />
khac nhau.<br />
a) Theo cdc dinh luat ca bdn qiiyit dinh toe do ciia qud trinh chia ra thanh:<br />
- Cac qua trinh co hgc dugc mo ta bdng cac dinh luat co hgc cua vat rdn. NTiima qua<br />
trinh dugc su dung de chuan bi nguyen lieu ran xa xu ly san pham cQng nhu la dl \an chuyin<br />
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Hoi nghi Khoa hoc ky' niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Not 10 2010<br />
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nguyen lieu co dang khoi, tang. Cu the cac qua trinh co hgc co the la: nghien, phan loai (sang)<br />
va trgn cac chat ran.<br />
+ Cac qua trinh thuy co co toe do qua trinh dugc xac dinh bang cac dinli luat cua thuy<br />
dong hgc - bg mon khoa hgc ve chuyen dong ciia cac chat long va khi. Thuoc ve cac qua trinh<br />
nay la van chuyen chat long, van chuyen khi va nen khi, phan rieng cac he chat long va khi<br />
khong dong nhat bang trgng lire (qua trinh lang) va bang ly tam, ciing nhu duoi tac dong ciia<br />
ap suat qua lop xop (qua trinh Igc) va trgn chat long.<br />
+ Cac qua trinh nhiet xay ra vol toe do dugc xac dinh boi cac dinh luat truyen nhiet - bg<br />
mon khoa hgc ve cac phuong phap lan truyen nhiet. Do la cac qua trinh dun nong. lam lanh,<br />
boc hoi va ngung tu ciia hoi. Thuoc ve cac qua trinh nhiet c6n la cac qua trinh lam lanh den<br />
nhiet do thap ban nhiet do moi tru6ng (cac qua trinh lam lanh vira va sau).<br />
Toe do ciia cac qua trinh nhiet a mire do dang ke phu thuoc vao cac dieu kien thuy dong (toe<br />
do, che do chay) de thuc hien chuyen nhiet giiia cac moi truang trao doi voi nhau bang nhiet.<br />
+ Cac qua trinh trao doi khoi (Ithuyech tan) dac trung bod sir chuyen mot hoac mot vai<br />
cau tir ciia hon hgp ban dau tir pha nay sang pha khac qua be mat phan each pha. Khuyech tan<br />
phan tu chat phan bo la giai doan cbam nhat vi the thuong la giai doan quyet dinh cua cac qua<br />
trinh trao doi khoi. Thuoc ve nhom cac qua trinh mo ta boi nhirng dinh luat truyen khoi la:<br />
hap thu, chung cat (chung luyen), trich ly tir dung dich, boa tan va trich ly tir vat ran xop, ket<br />
tinh, hap phu va say.<br />
Qua trinh trao doi khoi xay ra lien quan chat che voi cac dieu kien thuy dong trong cac pha<br />
va tren ranh gioi pha. Thu6ng thi ciing voi trao doi khoi c6 ca trao doi nhiet.<br />
+ Cac qua trinh hoa hoc (phan ung) xay ra voi toe do quyet dinh boi cac dinh luat ciia<br />
dong hgc boa hgc. Nhung cimg voi cac phan ling hoa hgc thu6ng la c6 sir chuyen khoi va<br />
nang lugng, tiep niia la toe do cac qua trinh hoa hgc (dac biet o quy mo cong nghiep) phu<br />
thuoc vao cac dieu kien thuy dong. Chinh vi the toe do cac phan irng tuan thii cac quy luat<br />
dong hgc vT mo va dugc quyet dinh boi giai doan cham nhat trong so cac tac dong hoa hgc<br />
lien tiep xay ra va khuyech tan.<br />
Tuong img vol cac qua trinh co ban tren co cac thiet bi co ban de thuc hien qua trinh ciia<br />
nganh cong nghe hoa hgc.<br />
b) Theo phuang phdp td chuc cac qua trinh cong nghe hoa hgc co ban chia ra gian doan<br />
va lien tuc.<br />
+ Cac qua trinh gian doan dugc tiln hanh trong cac thiet bi ma sau nhiing khoang thai<br />
gian nhat djnh nap nguyen lieu ban dau vao thiet bi de xir ly chung roi lai thao san pham ra<br />
khoi thiit bi. Nhu vay qua trinh gian doan co dac trung la tat ca cac giai doan deu xay ra 6<br />
mot cho (trong mot thiet bi) nhung a thai gian khac nhau.<br />
+ Cac qua trinh lien tuc thuc hien trong thiit bi ma viec nap lieu va thao san pham dugc<br />
thuc hien ding thai va lien tuc. Nhu vay qua trinh lien tuc c6 dac trung la tat ca cac giai doan<br />
cua no dIu xay ra dong thai nhung 6 nhung ch6 khac nhau trong khong gian tiic la thuc hien<br />
o nhung phdn khac nhau ciia thiit bi hay o nhung thiet bi khac nhau.<br />
So voi qua trinh gian doan, qua trinh lien tuc co uu diem:<br />
- Co kha nang tu dong hoa va co gioi hoa qua trinh, qua do giam lao dong thii cong den<br />
mire toi thieu.<br />
- Co tinh In dinh cao, qua do tang nang suat va chat lugng san pham.<br />
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Tieu ban: Moi truang va Nang luang ISBN: 978-604-913-013-7<br />
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- Co the trang bj dong bg, qua d6 giam gia dau tu va gia thanh.<br />
c) Theo su thay doi ciia cdc thong so trong thai gian<br />
Cac thong so ciia qua trinh (toe do, nhiet do, nong do...) thay doi theo th6fi gian va cac qua<br />
trinh dugc chia ra thanh.<br />
+ Cac qua trinh on dinh<br />
+ Cac qua trinh khong on dinh<br />
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2.3 Quy luat dong hoc cua cac qua trinh co ban<br />
Khong hieu dong hgc ciia cac qua trinh thi khong thi tinh dugc cac thong s i co ban ciia<br />
thiit bi.<br />
Quy luat dong hgc ciia cac qua trinh thuy co, nhiet, trao dli khoi va boa hgc co thi phat<br />
trien 6 dang dinh luat tong quat sau: Tdc dd qud trinh ty le thuan vai ddng lire vd ty le nghich<br />
vai trd luc. Ggi dai lugng ty le nghich voi tra luc la he sd tdc do ta co thi vilt cac phuang<br />
trinh dong hgc co ban sau:<br />
a) Ddi vdi chuyen ddng ciia ddng vdt lieu (Idng hay khi) qua thiit bi<br />
dV Ap ,<br />
rdT i?|<br />
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Trong do V- the tich chat 16ng chuyin qua, F- tilt dien thiit bi; T- thai gian; K|-he s i tic<br />
do qua trinh (dai lugng nghich dao ciia tro lire thuy lire Ri)<br />
b) Ddi vdi trao ddi nhiet:<br />
do ^t /-.^<br />
Fa T /?,<br />
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c) Ddi vdi trao ddi chdt tic pha ndy sang pha khdc<br />
dM Ac<br />
- K,hc (3)<br />
Fd T i?3<br />
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Trong do M-lugng chdt chuyin tir pha nay sang pha khac; F-bl mat tilp xiic pha- K3 - he<br />
so truyen khoi (dai lugng nghich dao tra lire khuylch tan R3); Ac- hieu s i giira ning do can<br />
bang va nong do boat dong ciia chat trong cac pha.<br />
d) Ddi vdi bien ddi hod hoc:<br />
dM<br />
--K/ic) (4)<br />
Vdz<br />
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Trong do M- lugng chdt da phan ung trong qua trinh hoa hoe; V-thI tich thiit bi" K4 - he<br />
so van toe qua trinh boa hgc; f (c) - dong lire cua qua trinh la ham s i nIng do cac chdt tham<br />
gia phan ung. '<br />
2.4 Nguyen tdc chung tinh thiet bj hoa chdt<br />
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^ Muc dich cua tinh toan cac qua trinh va thiit bi hoa hgc la xac dinh cac dong khii luona<br />
vat heu dugc che bien, xac dinh tieu bao nang lugng dl thirc hien qua trinh va tinh nhirng kich<br />
thuoc CO ban cua thiet bi va may moc. ^<br />
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Hoi nghi Khoa hoc ky niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Noi 10/2010<br />
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Nhung viec can lam:<br />
- Tir dieu kien thuy dong xac dinh dieu kien can bang va huong di ciia qua trinh. cac gia trj<br />
dau va cuoi ciia cac thong so.<br />
- Lap can bang vat chat:<br />
<br />
X G. = Z G, (5)<br />
Trong do: Yfii' lu^png vat lieu ban dau; XGc - lugng san pham cuoi ciing<br />
- Lap can bang nhiet:<br />
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Trong do Qj - lugng nhiet vao thiet bi cimg vat lieu ban dau; Qqi - hieu img nhiet ciia qua<br />
trinh; Qc - lugng nhiet rai thiet bi ciing san pham cuoi; Qmt - lugng nhiet mat mat vao moi<br />
truang.<br />
- Theo cac dai lugng dac trung cho thong so lam viec va can bang xac dinh ddng luc cua<br />
qud trinh tren co so cac dinh luat ciia dong hgc (thuy dong, nhiet, khuyech tan, hoa hgc) tim<br />
he sd tdc dd ciia qud trinh.<br />
- Xac dinh kich thudc ca ban cua thiet bj: dung tich, tiet dien, be mat dot nong, be mat tiep<br />
xuc pha... bang each sir dung he thirc<br />
<br />
A =^ (7) '<br />
DK<br />
Trong do A- kich thuoc co ban ciia thiet bi; M - lugng vat lieu che bien trong 1 don vi thai<br />
gian; D - dong luc ciia qua trinh; K- he so toe do ciia qua trinh.<br />
Qua phan trinh bay o tren ta thay viec hieu ro cac qua trinh cong nghe hoa hgc co ban va<br />
thiet bi de thuc hien chung cho phep ta:<br />
1) Trong nghien cim khoa hgc co phuong phap nghien cim hgp ly, co kha nang thirc hien<br />
va danh gia ket qua chinh xac de chinh ly va khai quat hoa cac ket qua khi irng dung<br />
vao thuc te san xuat.<br />
2) Trong thiet ke biet danh gia va lira chgn so do cong nghe va loai thiet bi thich hgp cho<br />
timg qua trinh; biet tinh toan, thiet ke thiet bi.<br />
3) Trong dieu hanh san xuat. de dang tiep can dugc che do lam viec thich hgp de nang<br />
cao nang suat thiet bi va chat lugng san pham; biet tim ra khau yeu trong day chuyen<br />
san xuat de cai tien.<br />
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3. MO HINH HOA CAC QUA TRINH CONG NGHE HOA HOC VA MOI TRUONG<br />
Mo hinh hoa toan hgc la phuong phap nghien cim hien dai ciia cong nghe hoa hgc va cong<br />
nghe moi truang. Phirong phap nay dugc ap dung rong rai trong viec nghien cim tinh toan,<br />
thiit kl va xay dung cac qua trinh cong nghe hoa hgc va moi truang [4-7].<br />
Mo hinh hoa toan hgc dugc thuc hien trong ba giai doan lien quan chat che voi nhau: 1)<br />
Xay dung mo hinh toan; 2) Lap chuong trinh bang mot ngon ngir thuat toan de giai tim gia tri<br />
ciia cac thong si; 3) Kilm dinh tinh tuong hgp ciia mo hinh voi qua trinh thuc.<br />
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Tieu ban: Moi truang va Ndng luong ISBN: 978-604-913-013-7<br />
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Trong cac giai doan tren thi xay dung mo hinh toan la kho khan va quan trgng nhat. O day<br />
doi h6i sir hilu bilt sau sdc ban chdt ciia qua trinh cdn mo ta bat dau tir nghien cim thuy dong<br />
hgc sau do rli moi din dong hgc nhiet, dong hgc chuyen khoi, dong hoa hgc, dong hgc phat<br />
trien ciia vi sinh vat...<br />
Mo hinh toan ting thi se cdu tao tir cac mo hinh cdp thap theo cau tnic phan cap. Vi du mo<br />
hinh ciia thiit bi phan ling hoa sinh co thi dugc ap dung cho mot thiet bi nhu aeroten hay biophin<br />
CO cau tnic nhu tren hinh 1.<br />
Ta thay rang co 5 mire phan cap (1 - V) tir thap den cao.<br />
Co so mo ta muc I la cac he thirc xet tod cac hien tugng hoa sinh xay ra trong te bao. Nliiem<br />
vu nghien ciiu ciia mire nay la giai ma co che cac qua trinh cue ky phirc tap trong te tao va chung<br />
a dang khai quat co the mo ta bieu dien sir phat trien ciia mot te bao rieng biet. Thuc te hien nay<br />
viec nay c6n chua lam dugc va ngu6d ta phai bat dau tir miic II.<br />
0 mire II la mo hinh dong hgc phat trien cua quan the vi sinh vat dugc hinh thanh tir nhiing<br />
mo hinh cap thap miic I. Hien nay nguai ta da chap nhan va dang sir dung rgng rai mo hinh dong<br />
hgc Monod, Andrews, Monod-Ierusalimsky.<br />
O miic III la nhirng he tbiic xac dinh dieu kien khuay trgn trong thiet bi. Trgn vi mo la dilu<br />
kien ly tuong, thuc te la trgn vT mo khi van ton tai nhimg hgp thi nao do. Danh gia mire do khudy<br />
trgn dugc thuc hien theo cong thiic Dankwerts.<br />
<br />
V Mo hinh thiet bi phan img hoa sinh<br />
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Mo hinh trao doi khoi Mo hinh thuy dong Mo hinh trao doi nhiet<br />
IV<br />
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III Mo hirih tron vi sinh Mo hinh tron vT mo<br />
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Mo hinh dong hgc tang truong<br />
II ciia quan the vi sinh vat<br />
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Mo hinh tang truong cua Mo hinh van tai va biin Mo hinh sinh hoa sinh<br />
mot te bao rieng biet doi CO chat trong te bao ly tuoi ciia te bao<br />
<br />
LTinh 1: Sa dd cdu true md hinh todn ciia thiit bi phdn icng hod sinh<br />
Cac mo hinh o miic IV mo ta cac qua trinh thuy dong, trao dli nhiet, trao dli chdt trong<br />
thiet bi. Mo hinh thuy dong hgc can nghien ciiu xac lap tren co so van dung cac mo hinh cdu<br />
triic dong tieu bieu trong thiet bi. Do la: Mo hinh ddy ly tu6ng; Mo hinh trgn ly tuong; Mo<br />
hinh khuyech tan (mot tham so va hai tham so); Mo hinh phii hgp.<br />
C6n mo hinh trao doi nhiet, trao doi chat dugc xac lap tren co so can bdng nhiet, can bdng<br />
chat CO tinh toi cac hieu ling nhu da noi a phan 1.<br />
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Hoi nghi Khoa hoc ky niem 35 nam Vien Khoa hoc va Cong nghe Viet Nam - Ha Noi 10/2010<br />
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Nhu vay tong hgp lai ta se co mo hinh toan ciia thiet bi phan img hoa sinh a mire V hinh<br />
thanh tir cac mo hinh cac mire thap. Mo hinh bao gom he phuong trinh (dai so, vi phan...) kha<br />
phirc tap tuy thuoc vao qua trinh cu the.<br />
Hien nay ky thuat va phuang tien tinh toan da phat trien den trinh do cao cho nen viec giai<br />
mo hinh toan c6 the noi co thuan Igi rat nhieu. Va nhu vay phuong phap mo hinli hoa toan rat<br />
nen va rat can dugc cac nha nghien ciiu cong nghe moi truang sir dung de dua ra dugc nhung<br />
giai phap cong nghe chinh xac va hieu qua.<br />
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4. iTNG DUNG QUA TRINH THIET BI CONG NGHE HOA HOC TRONG Xlf LY 6<br />
NHIEM VA BAO VE MOI TRLTCJNG<br />
Moi quan tam chii yeu trong khi thiet ke cac cong trinh xir ly 6 nhiem va cac thiet bi ciia<br />
chung la phai van dung dugc nhiing thanh tuu moi nhat ciia cac nganh khoa hgc cong nghe,<br />
dua ra dugc nhiing giai phap tien bg va kinh te nhat de cong trinh hoat dong hieu qua va lau dai.<br />
Nhu da noi a tren trong nghien cim tinh toan thiet ke che tao cac cong trinh xir ly 6 nhiem<br />
ngoai nhung kien thiic co ban ve hoa, ly, sinh c6n phai hieu sau sac cac qua trinh thiet bi co'<br />
ban ciia cong nghe hoa hgc tien hanh cong viec theo bai ban neu tren ket hgp ca phuong phap<br />
mo hinh hoa toan hgc de tiet kiem thai gian, cong sue va ca vat chat trong trien khai img dung.<br />
4.1 Lira chon phuong phap xu' ly 6 nhiem<br />
Ton tai nhirng phuong phap khac nhau, nhieu qua trinh khac nhau de xir ly 6 nhiem (nuoc<br />
thai, khi thai, chat thai ran). Vi du khi xem xet van de xir ly nuoc thai ta thay cac phuang phap<br />
xir ly dugc chia thanh ba nhom Ion:<br />
A. Cac phuang phap tren co so tach tap chat.<br />
B. Cac phuong phap tren co so bien doi tap chat.<br />
C. Cac phuong phap boa sinh<br />
Sir dung cac phuong phap nhom 1 dan den viec tach tap chat ra kh6i nude ma khong lam<br />
thay doi nhirng tinh chat boa hgc ciia no. Dieu nay c6 dugc trong tru6ng hgp khi ma nuac va<br />
tap chat nam a nhirng trang thai pha khac nhau cung nhu ca trong truong hgp chung tao thanh<br />
1 pha. Neu nuac va tap chat nam a 1 pha (vi du tao nen 1 dung dich thuc sir) va theo suy luan<br />
thay khong the true tiep sir dung cac phuang phap ciia nhom mot thi nuoc can xu ly can phai<br />
CO xir ly so bg dua tap chat ve mot pha khac. Do vay cac phuang phap nh6m mot lai dugc<br />
chia thanh hai nhom nh6.<br />
Al. Tach true tiep tap chat ra khoi nuoc<br />
A2. Thay doi trang thai pha cua nuoc<br />
Doi vol nhom nho Al la cac phuong phap:<br />
A L L Tach co hgc cac tap chat Ion (sang, luoi)<br />
A1.2. Lang<br />
A1.3. Ly tam<br />
A1.4. Lgc<br />
A 1.5. Tuyen noi<br />
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A1.6. Dien ly<br />
Al .7. Cac phuong phap mang (sieu lgc, tham thau ngugc)<br />
Thuoc ve nhom nho A2 la cac phuang phap:<br />
+ Neu tgp chdt - pha khi; nude - pha Idng:<br />
A2.1. Khir khi<br />
A2.2. Chung cat<br />
A2.3. Bay hoi<br />
+ Neu tgp chdt - pha Idng hay rdn; nude -pha khi: A2.4. Co dac<br />
+ Neu tgp chdt vd mcdc - hai pha Idng khdng trdn vdo nhau: A2.5. Trich ly<br />
+ Neu tgp chdt -pha rdn; nude -pha Idng<br />
A2.6. Kit tinh<br />
A2.7. Hdp thu<br />
A2.8. Keo tu<br />
Cac phuang phap biin doi tap chdt nhom B vai su thay dli thanh phdn hoa hgc cua chiing<br />
theo tinh chat cac qua trinh xay ra dugc chia ra thanh cac nhom sau:<br />
Bl. Hinh thanh cac chdt dien ly kho tan<br />
B2. Hinh thanh cac hgp chat o phan ly<br />
B3. Hinh thanh cac hgp chdt phirc<br />
B4. Tong hgp va phan giai<br />
B5. Cac qua trinh oxy hoa - khir trong d6 co ca cac qua trinh dien boa<br />
B6. Nhiet phan<br />
Cac phuong phap boa sinh nliom C la mot nhom dac biet bao g i m cac phuang phap boa ly<br />
va vi sinh de lam sach.<br />
Nhu vay can phai xem xet lira chgn dugc phuang phap xir ly thich hgp can cii vao yeu cdu<br />
xir ly, kha nang cho phep.<br />
4.2 Xay dyng so do xu- ly va nghien ciru cong nghe xu ly trong phong thi nghiem<br />
Thu6ng thi de lam sach nuoc thai din giai han cho phep cdn phai ap dung nhilu phuang<br />
phap va tuong ung ta se co nhilu qua trinih co so ciing cac thiit bi tuong ling. Tir do ma hinh<br />
thanh nen mot so do cong nghe xir ly.<br />
Trong so do cong nghe nhu vay se c6 nhilu don vi qua trinh va chung lien kit vai nhau<br />
bai cac d6ng vat chat va nang lugng. Cdn phai phan tich ky dong hgc cua qua trinh, tinh toan<br />
kha nang thiet bi. Ngoai ra can nho rang viec t l chirc d6ng trong he thing co vai tro quan<br />
trgng trong viec hinh thanh he thong hoeit dong hieu qua. N I U ap dung phuang phap mo hinh<br />
hoa toan hgc da noi a myc 2 thi co the tien hanh phan tich va ting hgp sa d l cong nghe tli uu<br />
ciia qua trinh xir ly 6 nhiem.<br />
<br />
Nghien ciru cong nghe xu ly thu6ng bdt ddu tir ph6ng thi nghiem. Thuc nghiem la dilu<br />
kien thiet yeu, la giai doan dau ciia nghien ciai trien khai mot qua trinh cong nghe. Kit qua<br />
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thuc nghiem luon la tieu chuan chii yeu de giai quyet mot nhiem vu thuc tien bat ky nao. Tuy<br />
nhien viec nghien cim cac qua trinh cong nghe moi truong thu6ng gan vai thuc nghiem cong<br />
kenh ton kem. De tang bieu qua nghien ciiu va giam thai gian can thiet de dua ket qua nghien<br />
cioi va giam th6'i gian can thiet de dua ket qua nghien cim vao thuc tien can phai toi un hoa<br />
qua trinh thuc nghiem tren tat ca cac buac tir tham d6 cho den khao sat anh huong ciia cac<br />
yeu to. Quy hoach thuc nghiem la phuong phap toi uu hoa qua trinh thuc nghiem.<br />
Quy hoach thuc nghiem hay thuc nghiem chii dong la tien hanh thirc nghiem theo ke<br />
hoach lap ra tii' truoc voi su thay doi dong thai ciia tat ca cac yeu to de nhan dugc nhieu thong<br />
tin chinh xac hon va lam tang dang ke hieu qua ciia qua trinh thuc nghiem.<br />
Co the dua ra dinh nghTa ve quy hoach thuc nghiem "Quy hogeh thuc nghiem Id thii tuc<br />
chon sd luang thi nghiem, cdc dieu kien tien hdnh thi nghiem cdn vd dit de giai quyet nhiem<br />
vu dat ra vdi dd chinh xdc cdn thiet. Id chon cdc phuang phdp todn hoc de xu ly kit qua thuc<br />
nghiem vd thica nhdn ket qud dd " [8,9]<br />
Vi du thong so toi uu hoa (dau ra) la hieu suat xir ly phu thuoc vao mot loai yeu to (thong so<br />
dau vao) nhu: cac nong do, nhiet do, pH... Sau khi xac dinh khoang bien thien (viing khao sat<br />
ciia cac thong so dau vao) nguai ta lap ke hoach bac mot N = 2'^, trong do k -la so yeu to, N -la<br />
so thi nghiem can thiet. Tren co so ket qua mo hinh bac 1 theo gradient va chuyen dan ve viing<br />
toi uu. O viing toi uu tien hanh ke hoach true giao bac hai Box -Wilson vol so thi nghiem.<br />
N = 2'' + 2k + no (8)<br />
Tong do 2 - nhan ke hoach; 2k- cac diem sao va UQ - so thi nghiem o tam ke hoach.<br />
Ma tran ke hoach thuc nghiem true giao bac hai ciia 2 yeu to co dang sau (bang 1):<br />
<br />
<br />
Bdng 1: Ma trgn trong true giao bdc hai Box - Wilson<br />
2 1<br />
STT Xo XI X2 X/ X2 XI X2' y<br />
<br />
1 -t- - - + + + yi<br />
<br />
2 -1- + - - + + y2<br />
<br />
3 -l- - + - + + y3<br />
<br />
4 + + + + + + y4<br />
<br />
5 + -a 0 0 a^ 0 ys<br />
<br />
6 + +a 0 0 a' 0 y6<br />
<br />
7 + 0 -a 0 0 a^ y?<br />
<br />
8 + 0 +a 0 0 a' ys<br />
<br />
9 + 0 0 0 0 0 yy<br />
<br />
Gia tri a dugc tra tir bang theo so yeu to k va so thi nghiem a tam Uo.<br />
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Trong truang hgp ting quat cua k yeu to ta co phuang trinh hoi quy. :;;; ,<br />
<br />
y = b,+ 1 b^Xj+ Z ^,x„ Xj+ y bjjx] (9)<br />
j - \ u.j = \ 7-1<br />
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Tong do: bo-thanh phdn tu do; bj- cac hieu ling tuyIn tinh; buj - cac hieu ling tuong tac doi;<br />
bjj - cac bieu irng binh phuong.<br />
Cac he si ciia phuang trinh hii quy dugc xac dinh nhu sau (a dang ma tran):<br />
B = (X*X)-'X*Y (10)<br />
Trong d6 X* - ma tran chuyen vi ciia X.<br />
Kilm dinh y nghTa ciia cac he si theo tieu chuan t (Student) va tinh tuong hgp cua mo<br />
hinh theo tieu chuan F (Fisher).<br />
Sau khi nhan dugc phuang trinh hoi quy tuong hgp co the tien hanh tim dieu kien toi uu<br />
theo thuat toan FLEXIBLE cua quy hoach phi tuyen [10].<br />
Nhu vay, viec sir dung quy hoach thuc nghiem cho phep ta tim dugc dieu kien toi uu tien<br />
hanh qua trinh nhanh chong va chinh xac.<br />
4.3 Chuyen quy mo thiet bi cong nghe moi tru-ong<br />
Trong khi nghien cim cac qua trinh cong nghe xir ly 6 nhiem van de chuyen quy mo c6<br />
mot vi tri quan trgng. Do la lam sao tir nhiing ket qua trong ph6ng thi nghiem hoac pilot can<br />
dua ra quy mo Ion hon (cong nghiep) trong trien khai thuc tien.<br />
Nhu ta da biet, viec chuyen quy mo cac qua trinh vat ly trong thiet bi co the thuc hien nho<br />
ly thuyet dong dang [11,12] la dong dang binh hgc, dong hgc va dong lire hgc: Tuong img voi<br />
chiing la nhirng chuan s6 dong dang c6 the nhan dugc tren ca so phan tich thir nguyen ciia cac<br />
dai lugng quyet dinh qua trinh. Can luu y rang viec xem xet dong th6fi mot so chuan so dong<br />
dang CO the dan den nhiing ket qua mau thuan nhau.<br />
Vi du voi thiet bi khuay trgn khi chuyen quy mo trong dong dang hinh hgc ta sir dung dai<br />
lugng cong suat rieng tinh tren mot don vi the tich:<br />
<br />
-=Idem (11)<br />
V<br />
Trong do: Idem - dinh so dong dang.<br />
Voi sir ket hgp voi mot so chuan so co the tim ra moi lien he giira cong sudt duong kinh<br />
(kich thuac co ban) ciia thiet bi.<br />
<br />
Df' (12)<br />
<br />
NghTa la de tang kich thuoc thiet bi len 2 ldn thi cong sudt phai tang 2" ldn.<br />
Trong truong hgp tong quat nguai ta tim quan he giiia cac chudn si vi du:<br />
Nu =y(Re, Pr,...) (13)<br />
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Hoi nghi Khoa hoc ky niem 35 ndm I'ien Khoa hoc vd Cong nghe Viet Nam - Hd Noi 10/2010<br />
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Md hinh hod todn hoc trong chuyen quy mo thiet bi cong nghe moi tru&ng<br />
Nhu da noi a muc 2 phuang phap mo hinh boa toan hgc dugc su dung rgng rai trong<br />
nghien cim cac qua trinh cong nghe hoa hgc va hoan toan co the dugc ap dung cho nghien ciru<br />
ciia qua trinh cong nghe moi truang cu the cho chuyen quy mo.<br />
De xay dung mo hinh toan cho qua trinh can:<br />
1. Tim mo hinh, dong hgc ciia qua trinh<br />
2. Nghien cim thuy dong hgc trong thiet bi bang each sir dung chat chi thi. ghi \ a xu ly<br />
cac du6ng cong F va C ket qua len tac dong bac va xung. Qua do, co the tim dugc mo<br />
hinh cau tnic d6ng phii hgp, thu6ng la dang mo hinh phoi hgp.<br />
3. Tren co so cac mo hinh dong hgc, mo hinh cau tnic d6ng tien hanh xay dung can bang<br />
chat va can bang nhiet.<br />
Mo hinh tong the cua qua trinh thuong la mot he phuang trinh (dai so phi tuyen hoac vi<br />
phan) va co the phan tich tim each giai roi kiem tra tinh tuong hgp cua no.<br />
Nho mo hinh toan viec tinh toan chuyen quy mo de dang hon va c6 co so chae chan hon.<br />
Trong nhirng nam qua Lien hiep KHSX Cong nghe hoa hgc da thuc hien nhieu de tai. du<br />
an trong ITnh vuc cong nghe moi tru6ng va nho ap dung phuong phap nay ma da trien kliai<br />
nhanh chong vao thuc te [13-16].<br />
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5. KET LUAN<br />
1) Qua trinh va thiet bi cong nghe hoa hgc la mon khoa hgc gan voi trien khai img diing ket<br />
qua nghien cim vao thuc te san xuat ciia nganh cong nghiep hoa chat voi phuong phap<br />
nghien ciiu hien dai la mo hinh hoa toan hgc.<br />
2) De trien khai img dung qua trinh thiet bi cong nghe hoa hgc trong xu ly 6 nhiem va bao ve<br />
moi tru6ng can phai can nhac lira chgn phuong phap xir ly, phan tich va tong hgp so do<br />
cong nghe, tien hanh toi uu hoa qua trinh thuc nghiem va ap dung mo hinh vat ly, mo hinh<br />
toan hgc trong tinh toan chuyen quy mo thiet bi.<br />
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TAI LIEU THAM KHAO<br />
Gerard Kiely, "Environmental engineering", The McGaw - Hill companies, 1997, 979 pp.<br />
KacaiKHH A.r., "Ocuoeubie npoijeccbi u annapamu xuMunecKoii mexuo.wpuu", M."<br />
XHMHJ)". 1971,784 c.<br />
<br />
J. HjiaHOBCKHii A.H., HuKonaeB H.H., "Hpoifeccbi u annapamu xuxtimecKoii u<br />
He(pmexuMuuecKoii mexuo.iopuu", M . , " X H M H H " , 1 9 8 7 , 496c.<br />
4. Ka(|)apoB B.B., "Memodbi KudepHemuKu e XUMUU U xuMimecKoii mexHO.noeuu", M.,"<br />
XHMHa", 1985,448 c.<br />
5. Ka(J)apoB B.B., '"'"Hpimijunbi cosdatiuR desoinxodubixXUMUHCCKUX npouseodcme", M.,"<br />
XHMHH", 1982, 288 C.<br />
<br />
6. Ka(|)apoB B.B., BunapoB A.K)., Fop^iecB JI.C, "Modciupoeauue duoxu.vimecKiix<br />
peaKmopoe", M.," JIecHa5i npoM-cxb", 1979, 342 c.<br />
7. Ka(J)apoB B.B., OepoB B.JT., MemajiKUH B.H., "HpuHijunbi MameMamimecKoeo<br />
ModenupoeaHUHxuMUKO-mexHo.iopimecKux ciicme.M", M.," XHMHJI", 1974, 352 c.<br />
8. AxnaaapoBa C.Jl., Ka(j)apoB B.B., "OnmuMU3ai{UM 3KcnepiiMeHma e XU.MUU U<br />
xuMimecKoii mexno.ioeuu ", M.," Bbicmaa mKOJia", 1985, 327 e.<br />
9. Pham Hong Hai, Ngo Kim Chi, "Xic ly sd lieu vd quy hogeh thuc nghiem trong nghien<br />
cicu hod hoc ", NXB Khoa hoc tu nhien va Cong nghe. Ha Noi, 2007, 188 tr.<br />
10. David M. Himmelblau, "Applied nonlinear programming", McGraw - Hill Book<br />
Company, 1972.<br />
11. Nguyen Minh Tuyen. Cdc phuang phdp trien khai cdng nghe hod hoc ", NXB Khoa<br />
hgc va Ky thuat. Ha Noi, 1987, 167 tr.<br />
12. Nguyen Bin, "Cdc qud trinh. thiet bi trong cdng nghe hod chdt vd thuc phdm ", Tap 1,<br />
NXB Khoa hgc va Ky thuat, Ha Noi, 2002, 262 tr.<br />
13. KoMHCcapoB lO.A., FopaecB JI.C, Hryeu Cyan Hryen, "AHaRU3 u cunmes cucme.vi<br />
eodoodecneHeuim XUMUHCCKUX npouseodcme ", M., " XHMHH", 2002, 496 c.<br />
14. Nguyen Xuan Nguyen, Pham Hong Hai, "Ly thuyet vd md hinh hod qud trinh xu ly<br />
nude thdi bdng phuang phdp sinh hoc", NXB Khoa hoc va Ky thuat. Ha Noi, 2003,<br />
288 tr.<br />
15. Luong Dire Pham, Nguyen Xuan Nguyen, Pham Hing Hai, "Ca sa khoa hoc trong<br />
cdng nghe bao ve mdi truong", Tap 4: Mo hinh boa cac qua trinh thiit bi cong nghe<br />
moi truang, NXB Giao due. Ha Noi, 2009, 408 tr.<br />
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NXB Khoa hgc va Ky thuat. Ha Noi, 2004, 200 tr.<br />
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