Study On Electrochemical Treatment Technology Of Salty Sewage In Refining And Chemical Industry

Water shortage and water pollution problems are getting worse with the rapid development of economy.The role of water resources in the national economy and people's lives is becoming more and more important,recent years,sewage treatment has received extensive attention.However,reverse osmosis concentrated water has become a difficult point in refinery chemical wastewater treatment because of its wide source,huge amount,complex composition and difficult biodegradation.Traditional physical,chemical,and biological methods have different degrees of limitations when dealing with reverse osmosis concentrated water.Electrochemical method has the characteristics of strong processing ability,strong impact resistance,no secondary pollution,complete degradation of pollutants and environmental friendliness.It has become a research hotspot.The advantages of dimensionally stable anode?DSA?electrodes include:outstanding catalytic activity,high mechanical strength,long life of the plates and low cost.The Ti/Ti-Ru O₂ electrode used in this study has received wide attention due to its higher catalytic activity and lower chlorine evolution potential.The main research contents of this paper include:?1?screening stainless steel electrode,graphite electrode and Ti/Ti-Ru O₂ electrode under the same condition to determine the best electrode suitable for reverse osmosis treatment of refinery chemical industry;?2?the factors affecting the electrochemical method were optimized,and five factors?p H value,chloride ion concentration,plate spacing,current density,processing time?were investigated.The influences of various factors on the treatment of reverse osmosis concentrated water were clarified.The optimal reaction conditions for the two-dimensional electrode treatment of refinery reverse osmosis concentrated water were determined;?3?three-dimensional electrodes were introduced into this paper,and the particle electrodes in the three-dimensional electrode were improved to improve the reaction efficiency;?4?the influencing factors of the three-dimensional electrode electrochemical method?particle electrode amount,p H value,plate spacing,electro-electrode between plates,processing time?were optimized.The optimum reaction conditions for the treatment of refining and reverse osmosis concentrated water by three-dimensional electrode electrochemical method were determined;?5?the high-resolution mass spectrometry was used to evaluate the degradation effect of wastewater.The Ti/Ti-Ru O₂ electrode and activated carbon electrode were characterized by XPS and BET methods;?6?the advantages and disadvantages of two-dimensional electrode electrochemical method and three-dimensional electrode electrochemical method were compared.The results are as follows:the chloride ion content in the sewage has the greatest influence on the electrochemical treatment effect When the refinery reverse osmosis concentrated water is treated with Ti/Ti-Ru O₂ electrode.The main mechanism of the Ti/Ti-Ru O₂ electrode method is to convert the chloride ions in the refinery reverse osmosis concentrated water into active chlorine such as Cl₂ and Cl O^-through its lower chlorine evolution potential.Such strong oxidizing active chlorine oxidizes and removes pollutants from refinery reverse osmosis concentrated water.When the two-dimensional electrode method is adopted,the chromaticity and ammonia nitrogen of the reverse osmosis concentrated water are completely removed,the 40min degradation rate of COD reaches 64.58%,and the 80min degradation rate reaches75.21%.When the three-dimensional electrode method is used,if the distance between the plates is 1.5 cm,the removal efficiency of the color,ammonia nitrogen and COD of the sewage is obviously improved,and the 45min degradation rate of COD reaches 85.83%.The processing efficiency of the three-dimensional electrode method is significantly higher than that of the two-dimensional electrode method,and the energy consumption is reduced.