Hydroxyl Radicals Formation in Dielectric Barrier Discharge During Decomposition of Toluene

A method based on high performance liquid chromatography (HPLC), has been developed to measure hydroxyl radical ((OH)-O-center dot) in plasma reactors. The determination was performed indirectly by detecting the products of the reaction of (OH)-O-center dot with salicylic acid (SAL). The applicability, and effect of time, specific input energy (SIE), relative humidity (RH), catalyst were investigated. It was found that 3 h was the optimal trapping time; concentration of (OH)-O-center dot was (5.9-23.6) x 10(13) radicals/cm(3) at SIE range. The highest (OH)-O-center dot yield and toluene removal efficiency (eta) were achieved with a RH of 20%. With MnO (x) , eta was two times that without catalyst, while (OH)-O-center dot yield in gas stream was one-sixth that without catalyst. However, if summed with (OH)-O-center dot adsorbed on catalyst surface, the total (OH)-O-center dot yield was the same as without catalyst. Experiments performed with/without toluene allowed to determine the role of (OH)-O-center dot on decomposition of toluene in air plasma.