Gas phase vinyl chloride (VC) oxidation using TiO2-based photocatalysis

Photocatalytic destruction of vinyl chloride (VC) was examined in a laboratory experimental set-up and the results were compared with those obtained from trichloroethylene (TCE) photocatalysis. Granular photocatalyst used in the study consisted of silica support coated with 0.1% titanium dioxide as the main photocatalytically active ingredient. Experimental work involved passing polluted air containing VC or TCE through a UV annular reactor at varying concentrations and residence times. Ultraviolet illumination was provided by low-pressure monochromatic mercury lamps with peak intensities at either 254 nm (germicidal) or 365 nm (black light). The operating temperature was constant at about 30 °C. UV photocatalysis provided greater than 80% VC removal at inlet concentrations of up to 60 ppmv and reactor gas retention times as low as 0.6 s. The overall removal capacity of the photoreactor was about 1000 g VC per m3 photocatalyst per hour (g m−3 h−1). Although this removal rate for VC was up to about 40% of that for TCE, this study is the first to obtain such noticeable photocatalytic destruction for VC, which is a biologically recalcitrant contaminant and its emission is a source of environmental concern.