Study On New Electrodes Used In Electro-Fenton For Degradation Of Phenols Waster Water

Wastewater containing phenols is a kind of important wastewater from industry. As they constitute treat to human health and produce a public concern, they have been listed among the 129 priority pollutants by the US EPA. They also have been listed in the priority pollutants that should be treated in our country. Because of the toxicity of phenols to microorganism, they are hard to be degradated in traditional biochemical technology. As one method of AOPs (Advanced Oxidation Processes), the application of Fenton is a hotspot in treatment of some organic wastewater. Electro-Fenton, developed from traditional Fenton, is one of the most prospective methods in wastewater treatment. The treatment efficiency of wastewater by Electro-Fenton is depended much on the characteristics of the electrode. In this paper, several new electrodes including the IrO₂/Ta₂O₅ electrode and two composite electrodes made of carbon materials were used in Electro-Fenton system. The primary achievements are as following: (1) The IrO₂/Ta₂O₅ electrode was employed in Electro-Fenton to degrade the 4-nitrophenol and the parameters of the treatment process were optimized. Under the optimized conditions more than 99% of 4-nitrophenol could be removed. (2) The preparation process of composite electrodes of Graphite-PTFE and Actived Carbon-PTFE were studied. Following conditions of preparation were accepted: PTFE as adhesive, ethanol as solvent and OP as disperse agent. Also the manufacturing procedures were established at the same time. Finally we made successfully the composite electrodes. (3) Two composite electrodes were employed to treatment the wastewater containing 4-chlorophenol. The results showed that the adsorption capability of Actived Carbon-PTFE was better than Graphite-PTFE. But the latter showed better performance than the former in Electro-Fenton.