摘要
Abstract
With the advancement of rural urbanization and industrialization of agriculture,the water environment has been polluted.The conventional water treatment plant(WTP)targets for the turbidity removal and pathogen deactivation,which cannot effectively remove the dissolved impurity in water,inevitably causing the change of tap water quality.Taking Q WTP in Xintai City,Shandong Province as an example,since 2010,the reservoir serving as the water source has been imported by cage fish culture and tributary river sewage,resulting in the deterioration of water quality with the increase of pollutants such as algal reproduction,permanganate index(CODMn)and ammonia nitrogen.The microcystin released by algae and geosmin(GSM)and 2-methylisoborneol(2-MIB)produced by actinomycetes metabolism seriously affect the quality of drinking water.According to the main composition of micropollutants,their change,environmental affecting factors and biological factors,the methods of strengthening conventional treatment,physical adsorption,chemical oxidation and biodegradation of micro-polluted source water were compared and analyzed.Results show that ozone(O3)can effectively oxidize algal odor compounds and microcystin.Considering that the local source water contains bromide,the combination of ozone oxidation and biological activated carbon(BAC)filtration is more reasonable.The test results showed that when the water temperature is about 10 ℃,the dosage of O3 is less than 2.0 g/L,and the contact time of BAC filter empty bed is 12 min,the removal efficiency of CODMn and ammonia nitrogen was 50％and 40％respectively,and bromate is less than 0.01 mg/L.Q WTP was upgraded using O3-BAC process,and the quality of effluent was stable and up to standard.Through continuous monitoring of treatment efficiency of O3-BAC process and intensive treatment operation control under low temperature conditions,it was found that in low temperature season,the friction of activated carbon filter layer under gas-water washing was intense.The biofilm fell off,and the proliferation was slow.The biological oxidation degradation was reduced,and the pollution removal effectiveness became worse.The complete mixed continuous reactor(CSTR)with water in parallel and O3 in series was used to increase the contact area of gas with liquid and the gas concentration difference,accompanying with the accelerating on the liquid film turbulence renewal.Compared with the common bubble reactor with water in series and O3 gas in parallel,CSTR greatly improved the solubility of O3 gas.By theoretical calculation,the cost of water production is reduced by 44.63％.关键词
饮用水/土臭素(GSM)/2-甲基异莰醇(2-MIB)/溴酸盐/臭氧化/生物降解/生物活性炭Key words
drinking water/geosmin(GSM)/2-methylisoborneol(2-MIB)/bromate/ozonation/biodegradation/biological activated carbon(BAC)分类
土木建筑
