Enhanced degradation of organic pollutant 4-chlorophenol in water by non-thermal plasma process with TiO2

摘要

The combined application of TiO2 photocatalyst and pulsed high-voltage electrical discharge process for the degradation of organic pollutant parachlorophenol (4-CP) in aqueous solution was tentatively investigated. The optimum conditions for 4-CP removal were applied voltage at 14 kV, electrode distance at 2 cm, pH at 6.5 (close to neutral solution), TiO2 concentration at 50 mg/L, gas source O2 at 100 L/h, and hybrid corona-streamer discharge mode. Introduced TiO2 into pulsed discharge plasma process under such optimum condition, the rate constant of 4-CP degradation (k cp) was greatly promoted, from 1.56×10−3 to 2.81×10−3 s−1, and energy efficiency for 4-CP removal was greatly enhanced by approximately one time, and it was attributed to more amounts of chemically active species (e.g., ozone and hydrogen peroxide, especially hydroxyl radicals) produced in pulsed discharge plasma process in combination with TiO2 photocatalyst.