ESEL Paper Review_20111012
By Hong Guo
1,Title and Author
Title: Effect of pre-ozonation on coagulation with IPF-PACLs: Role of coagulant speciation
Liu Hailonga,b, Wang Dongshenga,*, Wang Mina, Tang Hongxiaoa ,Yang Mina
a State Key Lab of Envir. Aquatic Chem., Res. Center of Eco-Envir. Sci., Chinese Academy of Sciences, Beijing 100085, China
b Environment and Resource Institute of Shanxi University, Taiyuan 03002, China
2. Summary of Paper
In this paper, a different of coagulants (AlCL3, PACL1.5, PACL 2.2 and PACL2.5) were synthesized as the coagulants. Those coagulants and different ozone dosage will be put into the water to test the coagulation performance under the influence of ozonation.
Effects of ozonation on coagulation with PACLs
With the same conditions for coagulation, a series of experiments were did by the different B value of the PACLs and ALCl3
Then we can find ozone exhibits coagulation aid effect with only PACL at certain B value. With AL(3), the ozone does not show any coagulation aid effect whereas PACL 1.5,2.2 significantly coagulant aid effect appearance at low ozone dosage(1.6ppm )
Here, we also find that the PACL2.5 does not have coagulant effect by increasing ozone dose. There is no marked effect on coagulation especially at the highest ozone dosage.
The result shows that the effect of ozone on coagulation depends on not only the ozone dose but also the speciation distribution of PACLs. The coagulation effect in PACL25 exhibits in more efficient coagulation in case of kaolin suspension.
And also the different property of the coagulants affects the coagulation performance. Experiments show that the more ALa fraction the coagulants has, the greater effect of pre-ozonation coagulation would be observed and the AlCL3 has the most ALa .but as we sye before, ALCL3 does not show any effect on the coagulation aid, then we can know actually the PACL1.5 has the most coagulants effect here.
This paper did a lot of experiment which do the test for the pre-ozonation on the coagulation efficiency. This is a very interesting experiment, because we have
already known that the ozone have enhance the organic matter to get together to make bigger flocs. And we can apply these phenomena to the water treatment area. But nobody did this on the alum and PACL, PAC before. So I think this paper can help us to investigate the possibility of using ozone to remove the phosphors in the advanced water treatment.