Degradation of Phenol in Aqueous Solutions by Gas–Liquid Gliding Arc Discharges

Abstract

The efficiency of a gliding arc reactor designed with the aim to degrade aqueous phenol solutions is studied as a function of supply voltage, electrode gap distance, and gas-liquid flow properties. This efficiency, which steeply increases when increasing the supply voltage, can reach 96% when the minimum electrode distance is fixed at 3 mm. Experiments show that phenol degradation efficiency also depends on solution pH, Fe 2+ addition, gas nature and gas flow rate. Furthermore, degradation pathways of phenol in aqueous solutions are proposed.

Application of Dielectric Barrier Discharge for Waste Water Purification

“…From previous experimental and modeling studies [4,13,14], the hydroxyl radical, the most important oxidant is mainly generated from water dissociation. …”

Degradation of 4-Chlorophenol using a Gas–Liquid Gliding Arc Discharge Plasma Reactor

“…Due to the action of the anodic and cathodic arc spots, Fe atoms are extracted from electrodes during plasma process with stainless steel electrodes, and oxidized to Fe 2+ . With the production of Fe 2+ , the Fenton's reaction should be added [28]:…”

“…The • OH radicals are responsible for the decontamination and strong oxidizing properties, whereas the NO • radicals are known as parent molecules for acid derivatives HNO 2 and HNO 3 , which induce acid effect [22][23][24][25][26]. Based on the advantages of electrical discharges in gas-liquid medium and the characteristics of humid air gliding arc discharge, several gas-liquid gliding arc discharge plasma reactors have been devised [27][28][29][30]. Wastewater is sprayed directly into the plasma zone formed between two electrodes through an atomizing nozzle in the gas-liquid gliding arc plasma reactor.…”

“…Wastewater is sprayed directly into the plasma zone formed between two electrodes through an atomizing nozzle in the gas-liquid gliding arc plasma reactor. Previous studies showed that the gas-liquid gliding arc plasma technique is adapted to the degradation of organic dye and phenol from aqueous solutions [27][28][29]. The species present in gas-liquid gliding arc plasma depend on the nature of plasma-producing medium.…”

“…The species present in gas-liquid gliding arc plasma depend on the nature of plasma-producing medium. In the case of the water-air, there is formation of H 2 O 2 , O 3 , nitrate, and H 2 in particular [28,30].…”