Electrochemical Degradation And Application Of Model Organic Pollutants Containing Oxygen And Sulfur Elements

With the rapid improvement of people's living quality and growing environmental awareness, people's quality requirements to environment has been increasing. As the industrial pollution situation are getting worse which causes the increasing impact on human life, the issue of the treatment of environmental pollution has given rise to more concern and attention.Complex wastewater containing the oxygen and sulfide elements such as odorous pollutants, phthalate esters and ethyl acetate are emitted from industrial process. As the emission standards are getting stricter and the need of classification before treatment, the research and development of efficient and clean technology are essential. Traditional technology such as chemical and biological oxidation in the application of processing organic waste water of these kinds are extremely restricted and it is difficult to meet the treatment requirements of such kinds of wastewater.In recent years, advanced oxidation technology of refractory organic pollutants is becoming a research hotpoint, in which electrochemical oxidation technology is considered as a green technology because of its mild reaction conditions, high catalytic activity through the electrode reaction at the scene, directly or indirectly generated hydroxyl radicals, without additional chemical oxidants, and therefore, electrochemical oxidation technology is widely used in the treatment of pollutants. Furthermore, electrochemical oxidation technology is suitable for treatment of many kinds of organics. Based on the current situation that this type of technology are less applied, this paper preliminary study the treatment of odorous wastewater, wastewater containing phthalate esters and effluent containing ethyl acetate.In this paper, F dopedβ-PbO2 anode was utilized to study the electrochemical degradation of the following categories of organic pollutants containing sulfur and oxygen elements in wastewater.1. With ethanethiol as a typical odor substances containing sulfur element, study various parameters on the degradation of ethanethiol simulated wastewater. Degradation of ethanethiol almost completed in early 10 minutes in reaction conditions of Na2SO4 1g/L, applied voltage of 7V, ethanethiol initial concentration 200mg/L, and the ultimate removal efficiency were more than 85%. Reaction temperature and applied voltage rarely affect the electrochemical degrdation of ethanethiol while the electrolyte concentration is beneficial for the electrochemical degradation. The increase of initial concentration lead to the increase of absolute and relative removal.2. Selecting ethyl acetate as a typical organic pollutants containing element of oxygen, we analyzed the parameters such as electrolyte type and concentration, applied voltage, reaction temperature and on the electrochemical degradation effects of ethyl acetate in simulated wastewater. Compared with utilizing Na2SO4 as electrolyte, NaCl showed better performance on the degradation of ethyl acetate. The increase of applied voltage shortened the degradation time of ethyl acetate by electrochemical technology. Removal of ethyl acetate and COD reduced in relatively high initial concentration of ethyl acetate, while the absolute removal increased. The circulation of electrolyte hardly effected the degradation of ethyl acetate and COD.3. Study on electrochemical degradation of environmental hormone substances dimethyl phthalate(DMP).Under conditions of DMP initial concentration 100mg/L, applied voltage 4V and NaSO4 1g/L as electrolyte, during first 2 minutes, DMP concentration decreased rapidly from 100mg/L to 15mg/L and thus the degradation efficiency reched 85%. DMP degradation efficiency was 99% in 5 minutes, almost completely degraded. The rise of voltage is favorable for the degradation of dimethyl phthalate and a relatively low voltage can attain economic superior.4. Based on the above research, we utilised the pilot amplification devices to treat organic sulfur ether odorous wastewater in the chemical plant. Electrochemical oxidation performed good adaptability of the ordorous wastewater with complex composition and unstable concentration. The treatment effect on the target pollutants were relatively stable and electrochemical degradation of diethyl sulfide and ethyl disulphide reached 70% and 50%. These results show that the electrochemical degradation has tremendous potential of treatmentment of odorous wastewater, phthalates substances and wastewater containing ethyl acetate. A novel treatment technology to address the complex organic ingredients wastewater and beneficial practical study were provided.