4-Chlorophenol Degradation and Hydrogen Peroxide Formation Induced by DC Diaphragm Glow Discharge in an Aqueous Solution

Abstract

In the present study, formation of hydrogen peroxide (H 2 O 2 ) and degradation of 4-chlorophenol (4-CP) induced by DC diaphragm glow discharge (DGD) in a sodium sulfate solution were investigated. The discharge was generated in a small hole on a quarts plate interposed between two submersed graphite electrodes. Experimental results showed that 750 V was the optimum voltage for H 2 O 2 formation and 4-CP degradation. Both the H 2 O 2 formation and the 4-CP degradation proceeded faster in cathodic compartment than in anodic compartment. Lowering the solution pH was favorable for 4-CP degradation but showed no appreciable effect on H 2 O 2 formation. Addition of hydroxyl radical scavenger (methanol) to the solution decreased the H 2 O 2 formation and the 4-CP degradation. Iron species especially ferric ions enhanced the 4-CP degradation markedly. Based on the analyzes of Current-Voltage characteristics and chemical effects, it was deduced that the mechanism of DGD was similar to that of contact glow discharge electrolysis.

Degradation of 2,4,6-Trichlorophenol Using Hydrogen Peroxide Catalyzed by Nanoscale Zero-Valent Iron Supported on Ion Exchange Resin

“…As an environmentally friendly oxidant, hydrogen peroxide has been used widely in the degradation of various organic pollutants, including chlorinated phenols. [14][15][16] Catalyzed by Fe 2+/3+ , UV or polyoxometallates, [17][18][19] chlorinated phenols can be degraded finally into carbon dioxide and water by hydrogen peroxide. Among the catalyst of hydrogen peroxide, Fe 2+ is the most effective, known as the Fenton reaction to produce hydroxyl radical.…”

Application of Dielectric Barrier Discharge for Waste Water Purification

“…The most part of known studies is devoted to investigations of the decomposition processes of water solutions of pure chemical compounds such as various organic dyes [1,9], phenol [2,4,6,8] and its derivatives (resorcin, pyrocatechol, hydroquinone) [ [7,10] and some others. At the same time, it would be interesting to check the capabilities of such methods for purification of real wastewaters.…”

Features of phenol degradation in aqueous solution in dielectric-barrier discharge in oxygen

“…Since the diffusion coefficients of the species in the liquid are low, it may be assumed that the result should depend on the reactor geometry, in par ticular, on the ratio of the solution surface area sub jected to treatment to the total area of the solution and on the thickness of the solution layer. Indeed, a decline in the efficiency of phenol decomposition with an increase in the volume of the solution was observed in [10] for a positive streamer corona discharge above the solution in an oxygen atmosphere. In that case, the entire surface of the solution was subjected to treat ment and the volume changed by varying the thickness of the liquid layer.…”

“…These methods show high efficiency and do not require the use of additional reagents. To date, the processes of destruction of a wide variety of substances (benzene derivatives, phenol and its derivatives, syn thetic surfactants, organic dyes, and other com pounds) using different types of discharge, such as dielectric barrier discharge (DBR), glow discharge, streamer discharge, diaphragm discharge, and gliding arc discharge, has been studied [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”