The Control Effect Of Chlorine Dioxide Preoxidation On The Formation Potential Disinfection By-products Of Microorganism

In the face of the continuous fermentation of water pollution in recent years,microbial contamination of water sources still occurs from time to time,and problems such as micro-polluted water and nutrient-rich water cause a large number of microorganisms in water.Bacteria,algae,humus and other microorganisms may increase the precursors of disinfection by-products,and produce by-products with potential safety hazards through traditional chlorine disinfection process,which will affect human health.In this paper,E.coli and Staphylococcus aureus are used as test objects,chlorine dioxide is used as oxidant,and according to the amount of final organic by-products,pre-oxidizers under different influence conditions are studied.Removal of bacterial chlorination disinfection by-product precursor(DBPsFP)by oxidation.When the drinking water source is contaminated by bacteria,the index of coliform bacteria in surface water ? can be increased from less than 104 cfu/mL to 105 cfu/mL,and the reservoir water source can be increased to 1010 cfu/mL at most,which affects the safety of drinking water.Conventional pre-oxidation technology can reduce the precursors of disinfection by-products and improve the quality of effluent.In this paper,the simulated contaminated water source containing Escherichia coli and Staphylococcus aureus was treated.By changing water quality conditions:temperature,pH,chlorine dioxide dosage,chlorination time,coagulant dosage and pre-oxidation reaction time,haloacetic acid(HAAs),halogenated ketones(HKs),haloacetones(HANs),halogenated nitromethyl(HNMs)and halogenated compounds were synthesized under different conditions.Effects of several disinfection by-products of methane(THMs).The results show that the concentration of TCM and DCAA decreases with the increase of chlorine dioxide concentration,while the concentration of TCNM,1,1-DCP and TCAA first increases and then decreases.The concentration of DCAN,TCAN and 1,1,1-TCP first decreases and then increases.On the whole,the pre-oxidant dosage of chlorine dioxide at 2 mg/L has a better effect on the removal of disinfection by-products precursors.With the increase of temperature,the concentration of DCAN and TCAN decreases first and then increases,while the concentration of 1-DCP,TCNM and 1,1,1-TCP decreases gradually,and the concentration of TCM,DCAA and TCAA increases gradually.From the above analysis,it is concluded that temperature can effectively control the formation of disinfection by-products.Generally speaking,about 20? can not only control the formation of disinfection by-products,but also effectively reduce the cost of water treatment.With the increase of pH value,the concentration of 1,1,1-TCP,DCAA,TCAA and TCNM gradually decreased and the concentration of TCM gradually increased.On the whole,the change trend of DBPs production of the two bacteria is similar,but because of the difference of amino acid and phosphoric acid,the trend of DBPs production of the two bacteria may be slightly different.For coagulation process,increasing the dosage of pre-oxidizer and coagulant and prolonging the pre-oxidation reaction time can effectively reduce some of the disinfection by-product precursors,but too long reaction time will increase the hydraulic retention time,increase the operation burden of waterworks.Excessive dosage of coagulant will increase the concentration of other pollutants in water.Comprehensive analysis shows that the optimal dosage of aluminium sulfate should be 30mg/L.The optimum dosage of chlorine dioxide is 2 mg/L,and the optimum pre-oxidation reaction time is 30 minutes.