Study On Adsorption-oxidation Synergistic Treatment Of Organic Wastewater By Activated Carbon Particle Electrode In Three-dimensional Fluidized Bed Electro-chemical Reactor

In order to meet increasingly stringent industrial wastewater discharge standards,it is crucial to develop green,efficient and low-cost industrial wastewater treatment technologies.In recent years,the industry has mostly adopted combined treatment technology to improve the treatment efficiency of the process,but the continuous combined water treatment technology is complicated,the investment is large and the efficiency is low.Therefore,the integrated technology that integrates multiple processing technologies has received great attention.Based on the integrating principle of adsorption and electrochemical advanced oxidation,a three-dimensional fluidized bed electrochemical reaction device was designed,and the mechanism and process rule of the three-dimensional electrochemical integrated process of fluidized bed to remove organic matter in wastewater were studied.The following research results were obtained:（1）A three-dimensional fluidized bed electrochemical reactor was designed by itself,and the rapid removal of methyl orange was realized.The best conditions are:When the concentration of activated carbon is 20.0 g/L,the working voltage is 15.0 V,the air flow rate is 1.0 L/min,and the ambient temperature is 25（±1）°C,the removal rate of methyl orange by the process reaches 99.9%in 30 minutes,and the synergistic effect coefficient can reach 57.28%.Activated carbon concentration,working voltage,air flow rate and temperature have a significant effect on the treatment effect.This process was found to have a high synergistic effect on the removal of high-concentration wastewater.（2）The synergistic mechanism of the efficient removal of methyl orange by the process was determined.Activated carbon is firstly polarized into particle electrodes in a fluidized bed electrochemical reactor.On the one hand,particle electrodes can enhance the effects of direct electrochemical oxidation and catalytic H₂O₂ decomposition to enhance·OH mediated indirect oxidation in the system,and on the other hand,its adsorption can enhance the degradation rate of methyl orange near the oxidation site.The process can achieve electrochemical regeneration while maintaining the efficient removal of methyl orange,so that the activated carbon maintains good recycling performance.（3）The effective treatment of industrial wastewater containing dimethylacetamide was realized by using the three-dimensional electrochemical coupling process of fluidized bed.The optimized process parameters obtained from the response surface analysis are:The activated carbon concentration is 50.0 g/L,the air flow rate is 2.0 L/min,the working voltage is 15.9 V,the Na₂SO₄ concentration is 0.222 mol/L,the temperature is 25（±1）°C,and the reaction time is 30 min,the COD value of the treated wastewater is 209 mg/L,the ammonia nitrogen concentration is 4.9 mg/L,the total nitrogen concentration is 75.5 mg/L,and the removal rates are 93.7%,85.2%and 84.0%,respectively.The established quadratic response model can effectively predict the actual COD removal rate of the process.The indicators of the treated wastewater meet the requirements of the second-class pollutant maximum allowable discharge standard of the"Integrated Wastewater Discharge Standard（GB 8978-1996）".