Photocatalytic Degradation of Chlorobenzenein Aqueous Solutionsa€“Comparison of Tio2 withPeriwinkle and Snail Shellsa€? Powder asPhoto Catalyst

摘要

Aim: The goal of the study is to determine the efficiency of periwinkle shell powder and snail shell powder – two locally prepared photocatalysts in comparison with TiO_(2) in the treatment of wastewater polluted with chlorobenzene.Place and Duration of Study: The present study was conducted between January and October 2011 at the Department of Chemical Engineering, University of Benin-Nigeria as part of a Master of Engineering Degree research project.Methodology: The obtained periwinkle (PSA) and snail (SSA) shells were crushed to powder, sieved and then analysed for the functional group (especially the transition metals) using Fourier Transform Infra-red (FTIR) analysis. The catalytic activity of the unmodified PSA, SSA as well as their modification with H_(2)O_(2) were then compared with commercial grade TiO_(2) (Degussa P25) for the degradation of chlorobenzene in wastewater both under laboratory condition (dark) and solar irradiation using sets of special boron-silica glass reactors. UV/VIS spectrophotometer model T70 installed with printer was used for the determination of chlorobenzene concentration while BET surface area of the catalysts was determined by means of nitrogen adsorption/desorption isotherm.Results: The result show that the photocatalytic activity of pure PSA and SSA were very poor when compared with TiO_(2). However, PSA and SSA modified with H_(2)O_(2) showed greater promise as their degradation efficiency increased by 87.98% and 41.72% respectively.Conclusion: PSA and SSA cannot be used as photocatalyst for the degradation of organic pollutants in aqueous solution without being modified or doped with appropriate metal or non metal dopants.