Advanced Wastewater Treatment Technology Based On Ozone Treating Urban Sewage Secondary Biochemical Effluent

To solve urban sewage treatment plant the second pond effluent,the problem of excess emissions of effluent COD and ammonia nitrogen,and put forward the economic and reasonable retrofit scheme,the existing sewage plant in the fourth quarter of 2015 in and out of the water COD,ammonia nitrogen,chromaticity and other conventional and unconventional index tracking monitoring and water quality analysis,and the existing problems are analyzed and summarized.Put forward the "ozone oxidation and biological aeration filter" the depth of the treatment process,through the orthogonal experiment and single-factor experiment to separate ozone oxidation and ozone/activated carbon oxidation conditions optimization study is made on two types of oxidation,from the perspective of economic and technical effect out of ozone/activated carbon oxidation method is more suitable for as a pretreatment method for the following biological treatment.Selected activated carbon as filling material in aeration biological filter,and the ozone/activated carbon and activated carbon oxide aeration biological filter series operation,respectively to investigate its under continuous flow conditions on the second pond effluent COD,total nitrogen and chroma removal efficiency,the main conclusions are as follows:1)The existing sewage treatment plant main problems is complex water quality,water composition containing the urban sewage and dye,chemical industry wastewater,water quality fluctuation by the year's monitoring and analysis of water quality.GC-MS showed that the second pond effluent residual COD is difficult to biodegrade.Water ammonia nitrogen concentration is about 11 mg/L,and low C/N.Effluent chromaticity should be eliminated.2)By the static optimization experiment conditions,the ozone/activated carbon oxidation than separate ozone oxidation on the second pond effluent COD removal efficiency 17%,2.78%,which can improve the biological sex,and 31.7%,reduce ozone flux has higher environmental and economic benefits,screening of ozone/activated carbon oxidation process as a pretreatment method for the following biological treatment.Ozone/activated carbon oxidation conditions optimization experiments show that the inlet COD is 105 mg/L,NH4+-N is 11.8 mg/L,ozone 30 min contact reaction time,pH of 9,ozone flux is 12.50 mg/L,activated carbon additive volume of 2/3,the second pond effluent COD removal rate as 45%,ammonia nitrogen removal rate was 44.9%.3)Select the best packing for activated carbon packing,under the condition of same water,activated carbon than ceramsite aeration biological filter 8.58% higher COD removal rate,and lower water chromaticity.Under the condition of continuous operation,ozone/activated carbon oxidation reactor in water COD was 89.7 ~ 109.8 mg/L,the effluent COD was 68.1 mg/L,the COD removal rate was 31%.Activated carbon aeration biological filter for 2 h in hydraulic retention time,the effluent COD are less than 50 mg/L,the COD removal rate was 21.4 ~ 54.7%.In water ammonia nitrogen concentration of 11.6 mg/L,the color for 450 times,after A series process,water is 3.9 mg/L,total nitrogen effluent colority for 5 times,water quality meet the urban sewage treatment plant pollutant discharge standard "(GB18918-2002)level of A standard(COD < 50 mg/L)."Ozone/activated carbon + aeration biological filter" can be used as the sewage COD and ammonia nitrogen emissions standard upgrade scheme.