Research And Application Of Urban Domestic Sewage Purification Treatment

With the economic development and the growth of urban population,the urban domestic sewage is also increasing,a large amount of sewage cannot be treated effectively,cause great pollution to ecology and environment.If the water quality after the secondary treatment of urban domestic sewage is used,on the basis of the original sewage treatment process,the post-treatment process of filtration and adsorption is added to make the water discharge meet the national standards,or even reuse standards,.It not only can alleviate the dilemma of water shortage,but also can prevent the harm to the environment.Therefore,the research of urban domestic sewage purification treatment has practical significance.By analyzing the filtration and adsorption principle of sewage,studied the influence of various factors on the filtration and adsorption effect of urban household sewage.Through designing orthogonal test,established the physical model of sewage treatment device by using CFD simulation software Fluent.Simulated the filtration and adsorption of sewage numerically,obtained the optimized process parameter matching by calculation.The purification effect of suspended solids,chemical oxygen demand(COD)and ammonia nitrogen in urban household sewage was verified by specific experiments under the optimized process parameters.Finally,designed the industrial equipment of urban domestic sewage purification.In this paper,the research and application of urban domestic sewage purification treatment are as follows:Firstly,the specific factors affecting the filtration and adsorption effect were studied by combining the filtration equation and adsorption diffusion equation according on the filtration and adsorption theory.Analyzed the influence of pore size and flow rate on wastewater filtration by Darcy formula and Ruth equation.Based on Langmuir adsorption theory Bohart and Adams equations,analyzed the effects of porosity and flow rate of activated carbon on sewage adsorption,and determined the independent variable factors.Secondly,designed L9(3~3)orthogonal test table with flow rate,pore size and porosity as three factors.Simulated the flow velocity and particle trajectory by Fluent software that in the process of sewage filtration and adsorption,Established the standard K-εturbulence model by counting the Reynolds number,chosen porous medium model and discrete phase model.Established simple two-dimensional model,obtained the optimized process parameters by changing the boundary conditions of the model,,the pore size is 20μm,the flow rate is 1 m/s,and the porosity is 0.6.In this case,92.5%of the particles were captured.The influence of pore size,velocity and porosity on the filtration and adsorption of sewage was analyzed,and the magnitude factors of influence degree is velocity<porosity<pore size.Thirdly,verified the numerical simulation results by using the experimental device with micro porous filtration and activated carbon adsorption functions.The process parameters optimized by numerical simulation to purify and treat urban household sewage,determined the pollutants in water samples.When the flow rate is1 m/s,the pore size is 20μm and the porosity is 0.6,the average removal rate of suspended solids in the experimental wastewater reaches 86.4%,which is close to the results of numerical simulation optimization.The ability of eliminate chemical oxygen demand and ammonia nitrogen is good,and the experimental pollutant removal rate is basically consistent with the numerical simulation particle capture rate.By comparison with national standards,water can be discharged.which conforms to the expected effect of urban household sewage purification treatment.Finally,based on the combination of optimal process parameters of filtration and adsorption wastewater treatment,designed the industrial treatment equipment for urban household sewage purification,which includes storage tank size,pump power,pipe diameter,water volume and other systems.Under the condition that the water quality of the plant is up to standard,the sewage treatment efficiency of the plant is improved to make it have the merits of high capacity,economic and environmental value.To sum up,this paper uses the composite process of micro porous filtration andIVactivated carbon filtration to treat sewage,organically combines theoretical research,numerical simulation and experiment,and obtains the optimal combination of process parameters for urban domestic sewage purification,which solves the problem of urban domestic sewage purification.