Photocatalytic degradation of trichloroethylene in aqueous phase using nano-ZNO/Laponite composites.
The feasibility of nano-ZnO/Laponite composites (NZLc) as a valid alternative to TiO2 to mineralize trichloroethylene (TCE) without difficulties for recovery of photocatalysts was evaluated. Based on the experimental observations, the removal of TCE using NZLc under UV irradiation was multiple reaction processes (i.e., sorption, photolysis, and photocatalysis). Sorption of TCE was thermodynamically favorable due to the hydrophobic partitioning into crosslinked poly vinyl alcohol, and the adsorption onto high-surface-area mineral surfaces of both ZnO and Laponite. The degradation efficiency of TCE can be significantly improved using NZLc under UV irradiation, indicating that ZnO-mediated heterogeneous photocatalytic degradation occurred. However, the degradation efficiency was found to vary with experimental conditions (e.g., initial concentration of TCE, loading amount of NZLc, the intensity of light and initial solution pH). Although the removal of TCE by NZLc was found to be a complex function of sorption, photolysis, and photocatalysis, the photocatalytic degradation of TCE on the surface of ZnO was critical. Consequently, developed NZLc can be applied as a valid alternative to suspended TiO2 powder, and overcome drawbacks (e.g., filtration and recovery of photocatalysts) in degradation of TCE for various water resources.
Korea Institute of Construction Technology, Water Resource & Environment Research Department, Republic of Korea.
Jin Chul
JC
Joo
Chang Hyuk
CH
Ahn
Dae Gyu
DG
Jang
Young Han
YH
Yoon
Jong Kyu
JK
Kim
Luiza
L
Campos
Hosang
H
Ahn
D000327:Adsorption; D002384:Catalysis; D003432:Cross-Linking Reagents / Q000737:chemistry; D005374:Filtration; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008027:Light; D053758:Nanoparticles / Q000737:chemistry; D010782:Photolysis; D011142:Polyvinyl Alcohol / Q000737:chemistry; D011208:Powders; D017640:Silicates / Q000737:chemistry*; D013816:Thermodynamics; D014241:Trichloroethylene / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D015034:Zinc Oxide / Q000737:chemistry*
D003432:Cross-Linking Reagents; D011208:Powders; D017640:Silicates; D014874:Water Pollutants, Chemical; D014241:Trichloroethylene; D011142:Polyvinyl Alcohol; C524813:laponite; D015034:Zinc Oxide
Crosslinked poly vinyl alcohol; Nano-ZnO/Laponite composites; Photocatalysis; Photolysis; Sorption; Trichloroethylene