Experimental Study On Advanced Treatment Of Chemical Wastewater By Advanced Oxidation Process

To achieve the goal of characteristic organic contaminants' removal from comprehensive wastewater in chemical industrial park, and make the effluent in sewage treatment plant steadily up to standard to discharge,the paper serves a sewage treatment plant's waste water in the chemical industrial park in Danyang as the research object. The original AO technology by the sewage factory cannot make effluent's COD reach the standard. Therefore,we plan to adopt two advanced oxidation,namely Fenton oxidation and ozone catalytic oxidation, combined AAO method to deal with wastewater, and compare two kinds of combination process comprehensively to choose a better solution ultimately. Through a series of experimental conditions, Fenton oxidation process survey some operating parameters on the treatment effect, including residence time, pH, the dosing quantity of H2O2 and the dosing quantity of PAM. For ozone catalytic oxidation process, the synthesis of catalyst and effects of different active component ratio catalyst for processing were studied. Besides,the paper examines some operating parameters, such as the ozone dosing quantity and hydraulic retention time. The optimal operating parameters of two advanced oxidation process were preliminarily determined.The results prove that on one removal of COD and UV254,Fenton oxidation first AAO biochemical behind is obviously better than the reverse order while the removal effects of ozone oxidation first or ozone oxidation latter were similar. But in view of the chroma removal, ozone oxidation latter is better. By the condition of Fenton oxidation and ozone catalytic oxidation process experiment, the optimization of Fenton oxidation process operating conditions are: residence time=2h,pH=3, c(H2O2):COD=1:1,m(Fe2+):m(H2O2)=1.7:1,dosing quantity of PAM=2mg/L. And the optimizing operation conditions of ozone catalytic oxidation process are: using the Mn-Ce-La(10:1:2) three components ozone catalytic oxidizer, ozone dosing quantity=50mg/L, the residence time of ozone=45min, pH maintain the original wastewater pH(pH=7-8). The removal rate of COD and UV254 can respectively reach 66% and 58% under the combination of Fenton oxidation and AAO while the removal rate of COD and UV254 can respectively reach 59% and 58%under the combination of ozone catalytic oxidation and AAO. The effluent COD of the two combined processes met the national second discharge standard,and other indicators such as ammonia nitrogen, total phosphorus reached the first level. The cost accounting shows that the cost of the combination of Fenton oxidation and AAO is 0.7825 yuan,and the cost of the combined process of ozone catalytic oxidation is 0.6245 yuan.