Advanced Treatment Of Printing And Dyeing Wastewater Based On Electrogenic Hydrogen Peroxide Coupled Ozone Oxidation

The discharge of industrial wastewater directly affects the surrounding water ecological environment,and printing and dyeing wastewater occupies an important proportion in industrial wastewater.Therefore,it is of great significance to carry out the advanced treatment of industrial wastewater represented by printing and dyeing wastewater to protect the water ecological environment.This paper mainly carried out the advanced treatment of printing and dyeing wastewater,pilot plant development and application research based on the electrogenic hydrogen peroxide coupled ozone(EH2O2/O3)oxidation,mainly including:Study on the effect and influencing factors of E-H2O2/O3 advanced treatment of COD,aniline and nitrobenzene in wastewater,based on the design and development of E-H2O2/O3 oxidation pilot plant,on this basis,the practical application effect of E-H2O2/O3 technology in the advanced treatment of printing and dyeing wastewater is studied.This study will provide important technical guidance for the treatment of printing and dyeing wastewater.The main research results are as follows:It is found that the synergistic effect of E-H2O2/O3 technology is obvious through the pilot experiment of secondary biochemical effluent of E-H2O2/O3 oxidation printing and dyeing wastewater.When the initial aniline is 1 mg/L,nitrobenzene is 4 mg/L,COD is 50 mg/L and HRT=2 h,in the reaction process of continuous 10 h,The removal rates of COD,aniline and nitrobenzene are 79.9%,99.9%and 89.1%respectively.Compared with E-H2O2,the removal rates of the three indexes are increased by 70.3%,93.5%and 71.1%respectively.Compared with O3,the removal rates of the three indexes are increased by 11.0%,10.0%and 45.7%respectively.The effects of ozone dosage,H2O2 dosage,hydraulic retention time(HRT)and initial pH on secondary effluent of E-H2O2/O3 oxidation were investigated.It was found that under the optimal conditions of ozone dosage of 48 mg/h,H2O2 dosage of 0.63 mmol/L,HRT=2 h and initial pH of 9.0,The removal rates of COD,aniline and nitrobenzene reached 85.0%,99.9%and 99.5%,respectively.No aniline was detected in the oxidized water and the concentration of nitrobenzene was only 0.02 mg/L,which was far lower than the discharge standard.In the design of pilot plant with E-H2O2/O3 technology as the core process,the combined E-H2O2/O3-BAC process flow is designed to ensure the effluent stability.and a pilot plant with a treatment scale of 48 m3/d and a cycle running time of 3 h is developed and designed.The pilot application effect of printing and dyeing wastewater based on E-H2O2/O3 oxidation is studied.The results show that when the influent COD is less than 90 mg/L,the effluent COD of the pilot system is less than 40 mg/L under the conditions of 120 g/h ozone dosage,0.63 mmol/L H2O2 dosage and 2 h HRT.The average removal rates of COD,UV254 and chroma reached 56.4%,89.5%and 89.3%,respectively.Three dimensional fluorescence spectrum analysis found that printing and dyeing wastewater secondary biochemical water contained five organic components,among which soluble microbial metabolites accounted for more than 65%.The EH2O2/O3 process is very effective in reducing the response value of fluorescent substances in the biochemical effluent of printing and dyeing wastewater.After the oxidation of E-H2O2/O3,the removal rate of total fluorescence intensity can reach more than 91%.According to the economic analysis,the treatment cost of the pilot system is 3.35 yuan/t.When the simulated influent flow rate is 10000 t/d,the operation cost of E-H2O2/O3 is about 1.53 yuan/t.