Non-thermal plasma-induced photocatalytic degradation of 4-chlorophenol in water

TiO2 photocatalyst (P-25) (50 mg L−1) was tentatively introduced into pulsed high-voltage discharge process for non-thermal plasma-induced photocatalytic degradation of the representative mode organic pollutant parachlorophenol (4-CP), including other compounds phenol and methyl red in water. The experimental results showed that rate constant of 4-CP degradation, energy efficiency for 4-CP removal and TOC removal with TiO2 were obviously increased. Pulsed high-voltage discharge process with TiO2 had a promoted effect for the degradation of these pollutants under a broad range of liquid conductivity. Furthermore, the apparent formation rates of chemically active species (e.g., ozone and hydrogen peroxide) were increased, the hydrogen peroxide formation rate from 1.10 × 10−6 to 1.50 × 10−6 M s−1, the ozone formation rate from 1.99 × 10−8 to 2.35 × 10−8 M s−1, respectively. In addition, this process had no influence on the photocatalytic properties of TiO2. The introduction of TiO2 photocatalyst into pulsed discharge plasma process in the utilizing of ultraviolet radiation and electric field in pulsed discharge plasma process enhanced the yields of chemically active species, which were available for highly efficient removal and mineralization of organic pollutants.