Experimental study on ozone photolytic and photocatalytic degradation of H2S using continuous flow mode

A foam nickel support was coated with TiO2 sols containing anatase particles. The malodorous compound, hydrogen sulfide (H2S), was removed via photolytic and photocatalytic oxidation processes under ambient conditions using a self-made photoreactor with 185-nm ozone (O-3) lamp illumination. The reactor degraded H2S with high removal efficiency. The effects of several factors, such as initial H2S concentration, ultraviolet light wavelength, relative humidity (RH), oxygen content, and catalyst deactivation and regeneration, on H2S degradation were investigated. The highest activity for H2S destruction was achieved with 80% RH, 21% oxygen content, approximately 200 mg/m(3) initial concentration, and 185-nm O-3 lamp illumination, resulting in higher conversion. Sulfur (S-0) and sulfate ion (SO42-) were detected as byproducts via the XPS technique. The catalytic activity was improved by SO42- promotion, but reduced by S-0 accumulation on the photocatalyst surface. In addition, by increasing the amount of SO42- generated, the yield of S-0 and catalyst poisoning could be controlled in the reaction. (C) 2011 Elsevier B.V. All rights reserved.