[Effects of absorption on photo-reduction of Cr (VI) by UV/TiO2 process and its elimination].
Reduction of Cr(VI) in aqueous solution were studied by the UV/TiO2 photo-reduction process. The results show that the photo-reduction of Cr(VI) ion by UV/TiQ2 agrees with Langmuir-Hinshelwood equation well. In absence of organic matters, absorption of TiO2 is the key step for this process, and optimal condition is pH = 1.5-2.5. The initial reduction rate correlate with pH value within pH = 1.5-10. The ability to competitively absorb to the surface of TiO2 can be ordered by PO4(3-) > SO4(2-) > Cl- > NO3-. Photoreduction rate and efficiency can be enhanced greatly with synergia of formaldehyde or formic acid, meanwhile synergia eliminate the effect of absorption. But synergic effects were reduced with phosphate.
Chen
Xin-man
XM
Hydrobar Research Center of Jinan University, Guangzhou 510632, China.
Xu
Ming-fang
MF
D000042:Absorption; D002384:Catalysis; D002857:Chromium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods; D014025:Titanium / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*
D014874:Water Pollutants, Chemical; D002857:Chromium; C009495:titanium dioxide; D014025:Titanium