Efficient H2O2 Production and Activation by Air Diffusion Cathode Combined with Ultraviolet for Lake Water Treatment: A Long-Term Evaluation

This study utilizes a natural air diffusion cathode (ADC) and an ultraviolet lamp to construct a UV/H2O2reactor for the in situ synthesis and activation of H2O2and evaluates its potential application in practical lake water treatment. The results indicate that the reactor exhibits stable treatment performance during a continuous flow experiment of 80 h. The air diffusion cathode maintains an H2O2concentration of above 350 mg·L−1in sodium sulfate electrolyte and shows no decreasing trend. Under the condition of approximately 59% H2O2utilization, the removal rates of COD and TOC are 37.6% and 40.0%, respectively; the rate of reduction of A254is 64.3%; while the total bacterial count removal rate reaches 100%. Large organic molecules in surface water are degraded to small organic molecules and mineralized to inorganic minor molecules. It effectively ameliorates the problem of organic pollution of surface water and effectively kills bacteria and improves the microbiological safety of the water body. Therefore, the UV/H2O2system developed in this study, based on electrochemically produced H2O2, is an effective method for treating micro-polluted surface water.