Research On Performance Evaluation Of O₃-BAC Process Treating Water From Qingyuan Lake Reservoir

Water pollution has been increasing significantly in china over the past decades,which is a big threat for our health and environment,while restricts the development of social economy.O₃-BAC?biological activated carbon?process would not generate DBPs precursors,it can remove refractory organic pollutants and effectively inactivate various types of pathogenic microorganisms in water,while the process is simple and low cost.This topic is mainly carried out for the quality and the characteristics Qingyuan reservoir expansion,and O₃-BAC process Qingyuan reservoir water depth treatment research to solve the current water quality does not meet the needs of urban development,aimed at the development of Qingyuan Waterworks Shanghe residents safety of drinking water,it can provide theoretical basis and great practical value.Studies include four parts:the effect of ozone oxidation,ozone dosing methods for bromate control,biological activated carbon filter operating results and O₃-BAC process for treatment of raw water reservoir Qingyuan effectiveness analysis.First,through the ozone oxidation of Qingyuan reservoir water,research effects of ozone dosage of ammonia nitrogen for BrO^3-,UV₂₅₄,DOC,COD_Mn.Studies show that when the ozone dosage over 5mg/L,Qingyuan reservoir raw water produce bromate BrO^3-risk concentration in excess of the presence of water through ozone oxidation treated.Removal of UV₂₅₄,COD_Mn is good,but for DOC,ammonia removal in general.Secondly,through the control of bromate dosage of ozone of Qingyuan change under the condition of reservoir water quality.Studies show that the first low ozone flow,prolonged dosing ozone,and then to high ozone flow,short-term dosing ozone dosing method,both to control the bromate BrO^3-generation of organic matter but also to ensure better removal.Then,the effects of biological membrane test and different hydraulic load,filter thickness,water temperature of biological activated carbon filter on the removal of DOC,UV₂₅₄,COD_Mn and ammonia nitrogen are studied..In the film experiment,the removal rate of DOC and UV₂₅₄ was not ideal and unstable,and unsuitable as a sign of the mature of the membrane of the biological activity..The NH₃-N and COD_Mn asthe markers of the mature of the biofilm are feasible and accurate..The optimum hydraulic load of the biological activated carbon filter is 0.3⁰.6m3/?m2·h?,the optimum filter thickness is 90¹20cm,the optimum water temperature is 25³0?.Finally,the removal effect of BrO^3-,UV₂₅₄,DOC,COD_Mn and ammonia nitrogen was evaluated,and the removal effect of the process before and after the process was compared..O₃-BAC process under the concentration of bromate BrO^3-maintain lower than national requirements of 0.01 mg/L in about 0.007mg/L,UV₂₅₄ removal rate remained at 65%,COD removal rate is maintained at 60%,DOC removal rate is maintained in 55% and NH₃-N removal rate remained at around 70%,the four water quality indicators removal rate has significantly improved compared with the original technology.