Study On Electrochemical Oxidation Conditions Of Phenol And Aniline Wastewater

Phenol and aniline are important chemical raw materials.They are also the organic pollutants most widely distributed the water environment,having the greatest impact.They cause enormous threat for the ecological environment,and seriously endanger the health of biological and human.At present,there are a variety of methods for the treatment of phenol and aniline wastewater,which still exist a variety of problems and deficiencies.Electrochemical oxidation,which called "green technology",has advantages in efficiency and lighter pollution.In this paper,phenol and aniline wastewater were the representative objects for the study of electro-oxidation process treatment of organic wastewater.This study included the treatment technology progress of phenol and aniline wastewater,the determination of phenol and aniline content in wastewater,and the electrolysis process conditions of phenol and aniline wastewater.The study had important theoretical significance and engineering applications.The solution of electro-oxidation of phenol or aniline wastewater contained non-conversion of phenol or aniline,and also the incomplete oxidation products such as benzoquinone and carboxylic acid.In this paper,the concentration of phenol or aniline were determined by a special UV Spectrophotometric Determination,the recovery of the method was 98%～102%,and the relative standard deviation was less than 2%.The method was simple and fast,and could be used in the study of electro-oxidation process of phenol or aniline wastewater.Phenol(or aniline) wasterwater was oxidated in the plate and frame electrolyzer, using PbO₂/Ti as anode,alloy electrode of lead and stibium as cathode,NaCl as supporting electrolyte.Through mono-factor experiments,influences of electrolyte, current density,initial concentration of phenol(or aniline),pH value,reaction time and flow of wastewater on the removal rate of phenol(or aniline) and the removal rate of COD were studied.The result indicated:When the wastewater containing 0.20 g·L^-1 of phenol was electro-oxidated on conditions as followed:sodium chloride concentration was 0.1 mol·L^-1,current density was 350 A·m^-2,the initial pH value was 5.5,the waste water flow was 100 L·h^-1,electrolysis time was 25 min,the phenol removal rate could reach more than 96%,COD removal rate more than 83%,and the average electric current efficiency 54.95%;When the wastewater containing 0.23 g·L^-1 of aniline was electro-oxidated on conditions as followed:sodium chloride concentration was 0.1 mol·L^-1,current density was 350 A·m^-2,the initial pH value was 6,the waste water flow was 100 L·h^-1,electrolysis time was 30 min,the phenol removal rate can reach more than 94%,COD removal rate more than 67%,and the average electric current efficiency 44.89%.