Optoelectronic Integration Processing Chlorophenol Wastewater

This work describes the methodological development of photocatalysis, anodic oxidation, paired electrocatalysis, and their coupling processes with photochemical technology and electrocatalysis, which helped to build up the technical platform of electrochemical methods for environmental application.Photooxidation of chlorophenol (CP) were conducted by the application of three different photochemical processes (UV, H2O2 H2O2/UV UV/ H2O2/air). The effects of reaction conditions such as the dosage of H2O2, initial chlorophenol, initial pH, were investigated in terms of CP degradation and chemical oxygen demand (COD) removal.A novel paired electrocatatlysis in the presence of ferrous ion that named anode-cathode electrocatalysis (ACE) was developed. It was found that CP degradation rate could be enhanced by 15% compared with that of individual anodic oxidation under similar conditions, and the promotion for COD was around 100%. The effects of pH, concentration and current on CP degradation were discussed, based on which the conditions for the synergetic effects were given.The combination of electrocatalysis and UV radiation greatly accelerated the removal efficiency. According to the pseudo-first-order reaction rate constant, the promoting factor for CP and COD abatement was 125.3% and 129.8%, respectively. Operating conditions were optimized to make the main reactions occurred in harmony. Higher removal rate was achieved when current is 0.7 A. Temperature has an effect on the CP degradation. However, considering the overall effect, it is advisable to carry out the process at ambient temperature. UV-assisted method can save the running cost to a certain degree and make the techniques possible for industrial application.The degradation behaviors of CP under process of anode electrocatalysis(AE), ACE and UV-ACE were compared, through which a possible degradation pathway was proposed. Strong oxidant, hydroxyl radical (OH), was generated through the reduction of oxygen on the surface of the cathode. A simplified mathematical model for CP and benzoquinone evolution was developed according to the proposed pathway, which could be well served to explore the influencing factors.