title: [Effects of absorption on photo-reduction of Cr (VI) by UV/TiO2 process and its elimination].
abstract: 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.
authors.affiliation: Hydrobar Research Center of Jinan University, Guangzhou 510632, China.
authors.forename: Xin-man
authors.initials: XM
authors.lastname: Chen
authors.forename: Ming-fang
authors.initials: MF
authors.lastname: Xu
mesh_terms: 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*
chemical_list: D014874:Water Pollutants, Chemical; D002857:Chromium; C009495:titanium dioxide; D014025:Titanium