The Effect Of Chlorine Dioxide Preoxidation On The Formation Potential Of Disinfection By-Products Of Microcystis Aeruginosa

In recent years,with the water eutrophication situation intensified,a large number of microbial breeding in the water,the traditional disinfection methods have reached the drinking standards,reduce the water quality.Among them,the extracellular organic matter and intracellular organic matter of Microcystis aeruginosa contain a large amount of organic acids such as amino acids,proteins,amino acids and fats.These substances can be used as disinfectant byproducts.After disinfecting,the disinfectant product.Related scholars have found that pre-oxidation technology can significantly reduce the quality of pre-toxic disinfection,reduce the follow-up burden of water treatment operations,improve water quality.Therefore,in this paper,the extracellular organic matter and intracellular organic matter of Microcystis aeruginosa were studied,and the influencing factors of potential of chlorinated disinfection by-products were studied by preoxidation of chlorine dioxide.In this paper,the effects of pH,chlorine dioxide dosage,preoxidation reaction time,temperature and coagulant dosage were investigated by changing the water quality conditions of the Microcystis aeruginosa.Trihalomethanes(THMs),Haloacetic Acids(HA),haloketone(HKs),haloacetonitrile(HANs)and halogenated nitrocellulose(HNMs).The results show that,along with the increased dosage of chlorine dioxide,the concentration of trichloroacetic acid(TCAA),trichloro acetonitrile(TCAN)and Trichloronitrobenzene(TCNM)increases at first and then decreases,the concentration of dichloro acetonitrile(DCAN)decreases at first and then increases,the concentration of trichloromethane(TCM),dichloroacetic acid(DCAA),1,1-dichloro propanone(1,1-DCP)and 1,1,1-trichloro propanone(1,1,1-TCP)decreases.The removal efficiency of DBPs is the best when the dosage of chlorine dioxide is 3 mg/L.The solution pH also has a significant effect on DBPs formation,the concentration of TCM increases with the raising pH in a range 5 to 9,TCNM increases at first and then decreases.On the contrary,the concentration of DCAA,TCAA,DCAN,TCAN,1,1-DCP and 1,1,1-TCP decreases continuously.When pH is 9,they would exceed their lowest concentration.With the lengthened pre-oxidation time,the concentration of TCM and 1,1,1-TCP increases,while the concentration of DCAA,TCAA,DCAN and 1,1-DCP decreases.The concentration of TCAN and TCNM shows a trend of first increases and then decrease.Temperature directly controls the reaction rate,so it will also indirectly affect the concentration of disinfection by-products,with the temperature changes from 10 ? to 30 ?,the concentration of DCAA,TCAA,TCM,TCAN increase slightly with temperature rise,the concentration of TCNM,DCAN,1,1-DCP,1,1,1-TCP decrease continuously.The DBPsFP can be controlled effectively by pre-oxidation and enhanced coagulation process.The 8 kinds of DBPS value reach the lowest when the coagulant dosage is 50mg/L.For the intracellular organic matter of Microcystis aeruginosa,the increase of pre-oxidizing agent,coagulant dosage and prolonging the preoxidation reaction time can effectively reduce the pre-product of some disinfection by-products,but the reaction time is longer,and the hydraulic retention time,Increase the burden of running the water plant,too high coagulant dosage will increase the concentration of other pollutants in the water.Comprehensive analysis,permanganate compound the best dosage should be lmg/L,the best pre-oxidation reaction time should be set to 30min,coagulant aluminum sulfate the best dosage should be set to 30mg/L.