M Haghighi - MSc,Social Determinants of Health (SDH) Research Center and Environmental Health Department, Health Faculty , Kashan University of Medical Sciences, Kashan, Iran
F Rahmani - PhD, Chemical Engineering Faculty, Sahand University of Technology, Sahand New Town, Iran
R Dehghani - PhD, Social Determinants of Health (SDH) Research Center and Environmental Health Department, Health Faculty , Kashan University of Medical Sciences, Kashan, Iran
A Mazaheri Tehrani - MSc, Social Determinants of Health (SDH) Research Center and Environmental Health Department, Health Faculty , Kashan University of Medical Sciences, Kashan, Iran

Aims The application of photocatalytic processes to remove heavy metals in aqueoussolutions and industrial wastewater are regarded as extremely effective, clean and withoutproducing waste methods. The goal of the present study was to investigate the photocatalyticactivity of ZnO based on H-ZSM-5 zeolite support.Materials & Methods ZnO/H-ZSM-5 composite synthesized by impregnation methodsuccessfully, and photo-reduction of Cr(VI) was investigated via this composite in present ofUV light irradiation. The prepared composite was characterized by X-ray Diffraction (XRD)and Field Emission Scanning Electron Microscopy (FESEM). Data was analyzed by repeatedmeasurement statistical test.Findings ZnO/H-ZSM-5 (79.5%) had better removal photo-reduction activity than pureH-ZSM-5 (8.7%; p=0.003) zeolite and ZnO (58.8%; p=0.003). The initial concentration ofCr(VI) was a highly influential factor in photo-reduction of Cr(VI); In the way that when theinitial concentration increased from 10 to 40mg/l, the photo-reduction percentage decreasedfrom 92.5 to 57.7% in constant operational conditions (p=0.001).Conclusion ZnO/H-ZSM-5 composite has higher removal photo-catalytic activity than pureZnO and HZSM-5 zeolite. Photo-reduction of Cr(VI) by ZnO/H-ZSM-5 composite is an efficienttechnology for the treatment of water and wastewater containing high concentration of Cr(VI).

Oxidation-Reduction; Hexavalent Chromium; Metals, Heavy