Study On Purification Of Micro-polluted River Water By Different Biofilm Carrier

In recent years,The urban economy has developed rapidlly,The population has increased rapidly,Industrial wastewater,domestic sewage and agricultural sewage production continues to increase,China's urban rivers generally have a sewage function,The river is subject to organic pollution,Part of the water quality indicators exceed the surface environmental quality standards.Micro-polluted river water refers to the organic pollution,nitrogen,phosphorus and toxic substances lower pollution of the river.Most of the flow through the city have micro-pollution phenomenon,As the current water treatment technology for the majority of high concentrations of industrial wastewater and domestic sewage,And river pollution has become a prominent water environment,So it is necessary to study the micro-polluted river water.In this paper,the present situation of river water treatment in China was analyzed,and the methods,principles and application prospects of river pollution control were analyzed and discussed.Taking Fuyang River in Handan City as the research objectusing biological contact oxidation process,conduct a pilot study by a self-designed bio-contact oxidation reactor,intended to be technical support for water quality improvement of urban river water bodies.The main contents of the experiment and the main conclusions are as follows:Select biological rope packing,combined bio-carrier and elastic filler as a representative filler.The reactor was activated by aexposure method and the effects of HRT ?DO and aeration / exposure time ratio on the reactor operating efficiency under the experimental conditions were investigated.After the analysis of the experimental data found that:Under the conditions of chemical oxygen demand?CODcr?and ammonia nitrogen?NH₄⁺-N?concentrations of 49.37 mg/L and 3.56 mg/L,respectively,the reactor can be started successfully in 30 days.The CODcr and NH₄⁺-N removal rates of the three fillers were stable at about 68% and 75%.HRT has some effect on the removal of contaminants from the three fillers,but not significant.When HRT is 24 h,the effect of filler on the comprehensive removal of pollutants is better.The average removal rates of CODcr,NH₄⁺-N,TN and TP were higher at the time of aeration / exposure time of 6 h: 6 h and HRT of 24 h,which were75.87%,76.05 %,37.1% and 25.41%.Using biological rope packing for testing,The effects of DO and packing density on the removal efficiency of pollutants were investigated.The trial found that: DO concentration and packing density had some influence on the removal efficiency of pollutants,but not significant,When the DO concentration was more than 6mg / L,the removal rate of COD and NH₄⁺-N The rise has been reduced.The removal rate of total nitrogen?TN?decreased with the increase of DO concentration,and the removal rate of total phosphorus?TP?was not high.With the increase of laying density,the removal rate of COD,NH₄⁺-N and TN is increasing,and the removal rate of TP fluctuates greatly.When the density is 60%,the effect is better.Three factors and three levels of orthogonal experiment were carried out on the three factors influencing the pollutant removal rate.Through the test results we can see: the order of the three factors influencing the removal rate of pollutants is:hydraulic retention time> dissolved oxygen> packing density.Comprehensive analysis CODcr,NH₄⁺-N,TN and TP removal effects,The optimum operating conditions under the experimental conditions are as follows:HRT = 24 h,DO = 6 mg / L,packing density of 60%.