Anh hiidng cua thdi gian p h a n iing
Hinh 1 mo ta qua t r i n h giam thieu COD theo thdi gian p h a n iing cua thi nghiem. Ket qua thii nghiem cu the cua chung toi chi ra r a t ro r a n g r^ng gia tri COD dat den gia tri khong doi sau 30 phiit. Ket qua nay la hoan toan phii hdp v6i cac thong so diia ra cua cac tai lieu da cong bo' va gop ph^n k h a n g dinh ve toe do chung cua phan iing
4_8 D6ng Kim Loan, Jan Koller...
Fenton (Lipczynska-Kochany et al., 1995; Hofl et al., 1997). Dong thdi thdi gian phan
iing 30 phiit n^y ciing se diidc chon s^ dung nhii Ik thdi gian ket thiic p h a n iing cho cac
day thii nghiem tiep theo.
Hinh 1. Hidu su^t xit ly COD theo thdi gian phan ulhg
A n h hiicfng cua ty le moi Fe^* / H2O2 den k h a nang loai bo AOX v^ COD
Ket qua t r e n h m h 2 cho thay hieu qua cua qua trinh p h a n buy phu thuoc kha ro
vko ty le nong do cua cac t h a n h p h i n xiic tac sat(II) vk nguon san sinh ra cac goc
hydroxyl - H2O2.
Trong qua t r i n h t h i nghiem, ty le moi cua Fe2'"/H202 diidc thay doi tii 1: 120 den 1:1640. Ket q u a cho t h a y k h i nong do satGD giam thi hieu qua xii ly AOX ciing nhii COD deu t a n g v^ hieu qua cao nhlft k h i sii dung ty le 1:810, 1:980 va 1:1230. Khi nong do sat(II) tiep tuc giam t h i hieu qua xii ly ciing giam.
COD G A O X 100 100 90 80 H % 70 60 50 40 30 20 10 0 . * ° . * " .•>-" K * ° .^'^'^ K^* K * ' . ^ < ^ ° K ^ / / T y l e m o i : Fe'^/HjO^
•
Ph&nhuyc^ch&hJhicoddchai...
H i e n t i i d n g t r e n c6 t h e diidc giai t h i c h b a n g cac cd che s a u :
* K h i n o n g do s i t (II) q u a cao se d i n d e n sii giam so liidng cac goc h y d r o x y l do x ^ y r a cac p h a n i i n g p h u ( N e y e n s , 2003):
0 H + F e 2 * - > 0 H + F e ^ * (9) * Ngiidc lai, k h i n o n g do s a t ( I I ) q u a tha'p se d i n d e n viec g i a m toe do ciia p h a n
iing.
T r o n g t4't c a cac t h i i n g h i e m d a t i e n h a n h d e u cho thiiy h i e u q u a g i a m AOX l u o n l u o n cao h d n h i e u q u a g i a m C O D ; d i e u n ^ y c u n g p h u h d p v6i so h e u c u a cac cong t r i n h n g h i e n ciiu d a c o n g bo t i i d n g tii (Hofl e t al., 1997).
5. Ket luan
K e t q u a n g h i e n ciiu c6 t h e t o m t ^ t n h i i s a u :
- P h a n i i n g F e n t o n to r a 1^ c6 t h d i g i a n p h a n iing n g a n . T r o n g triidng h d p cu t h e n g h i e n ciiu p h i n hiiy 4 - C P d a cho t h ^ y gia t r i COD d a t gia t r i k h o n g doi ciing chi t r o n g k h o a n g 3 0 p h i i t .
- T r o n g m o i t r i i d n g h d p cu t h e k h i a p d u n g p h a n iing F e n t o n c a n t h i e t p h a i t i m r a n o n g do toi liu ciia cac t a c n h a n . Ty le moi Fe^* / H2O2 l u o n d o n g m o t vai t r o q u a n t r o n g ; k h i t y le n a y q u a cao h a y ngiidc lai q u a t h a p d e u d a n d e n sii g i a m h i e u q u a xii ly c u a q u a t r i n h .
- T r o n g t a t c a cac t h i i n g h i e m d a t i e n h a n h , h i e u q u a xii ly AOX l u o n 16n h d n h i e u q u a xii ly C O D .
TAI L I E U T H A M K H A O
[1] Arslan I., Balcioglu I.A., Bahnemann D.W., Heterogeneous photocatalytic treatment of
simulated dyehous effluents using novel TiOzphotocatalysts, Applied Catalysis B:
Environmental, 26(2000), pp.193-206
[2] SN EN 1485, J a k o s t vod. Stanoveni adsorbovatelnych organicky vdzanych halogen
(AOX), 1998. (adsbygoogle = window.adsbygoogle || []).push({});
[3] Goi A., Trapido M., Hydrogen peroxide photolysis. Fenton reagent and photo-Fenton for
the degradation of nitrophenols: comparative study, Chemosphere, 46(2002), pp.913-922
[4] Hofl C , Sigl S., Specht O., Wurdack L, Wabner D., Oxidative degradation of AOX and
COD by different advanced oxidation processes: a comperative study with two samples