The Sulfide Oxidation in an Electrolytic Sulfide Oxidizing Bioreactor using Graphite Anode

Abstract

The goal of the present research was the direct conversion of sulfide (an important contaminant in various industrial wastewaters) to sulfate, whose discharge limits are much less stringent than those for sulfide. The electrolysis of sodium sulfide was investigated under different conditions such as: pH, current density and working area etc. along with cyclic voltammetry. By the use of a graphite anode, we achieved near-quantitative electrochemical conversion of sulfide ions to sulfate with current efficiency of 88%. Kinetically, the reaction is first order in current density. The experimental results revealed that the sulfide removal rate of more than 88% could be achieved under the conditions T=30 ℃, pH = 7, current density of 1mA/cm2 at anode area of 225 cm2 .The process can be practically coupled with bioreactor for an effective sulfide removal.