Photooxidation of phenolic compounds in aqueous solution with a vacuum-UV lamp

The decomposition of phenolic compounds (phenol, p-chlorophenol, and p-nitrophenol) in wastewaters by VUV direct photolysis and VUV/H2O2 process with a 185 nm Vacuum-UV lamp in a batch photoreactor was studied under various solution pH values and purging gases (N2 and O2). The photolytic properties of these phenolic compounds were found to be highly dependent on the solution pH. Experimental results for the VUV alone system revealed that photolytic rates of organics by purging O2 were apparently larger than those by purging N2 and the removal of organics was found to be above 95%. For the 185 nm/VUV/H2O2 process, the reaction rates were significantly raised compared to those by direct photolysis.