On the Performance of Free Radicals Combined Electrocoagulation Treatment Processes

The electrocoagulation (EC) combined treatment processes have shown promising performances in which the removal of pollutants from industrial wastewater was greatly enhanced. The integration of a free radical producing step with EC has been considered as one of these new combinations that show synergy and improvements in the overall cleaning process performance. This review is devoted to discuss and analyze references on free radicals-assisted EC processes. Different combinations of free radical mechanisms were cited in the literature during the last two decades. They included ozone, advanced oxidation and ultrasound energy-assisted EC. It was noted that most of those studies were lab-scale processes that used synthetic wastewaters rather than real wastewaters. In addition the performances of those combined processes were improved compared to the EC process alone. This review considers the main parameters of free radical EC processes such as mechanisms, kinetic models, scale-up and cost estimation. Many concluding remarks were stated to give insights for possible future investigations. It seems from the results that the ozone-assisted EC is the most efficient combination since its removal efficiency is high in most applications. On the other hand, the combination of ultrasonic energy with EC was reported to reduce electrode passivation.     

负载型钴锰复合氧化物臭氧辅助催化降解低浓度甲醛的性能研究

制备了负载型钴锰复合氧化物Co-MnOx/ZSM-5催化剂,采用浸渍法将催化剂负载到堇青石蜂窝陶瓷上,在密封舱内进行催化降解甲醛研究,考察了室温下臭氧辅助催化降解室内低浓度甲醛的特性。同时,也探讨了催化剂制备工艺对催化剂活性的影响。实验结果表明：在500oC煅烧温度条件下制备的10% Co-MnOx/ZSM-5催化剂具有最高的催化活性。通过XRD、BET、TEM、XPS和TG-DSC等手段的表征结果表明,其高活性可能是主要来自于形成的CoMnO3晶相和Mn4 与Mn3 价态共存。