Study On Removal Efficiency Of DBPsFP From Water Source By Coagulation/Preoxidation Coagulation

At present,drinking water source is affected by river and groundwater pollution,more and more reservoir water is used as drinking water source,so the DBPsFP in reservoir water is also widely valued.In this paper,the reservoir water is used as the test water sample to study the influence of two coagulants and two preoxidizers on the premise of disinfection by-products under the condition of coagulation alone,combined with preoxidation and coagulant.Under the condition of using coagulant alone,with the increase dosage of coagulation,the concentration of Trichloromethane(TCM),1,1-dichloroacetone(1,1-DCP)?and dichloroacetonitrile(DCAN)decreased at first and then increased,the concentration of 1,1,1-trichloroacetone(1,1,1-TCP)increased gradually,the concentrations of dichloroacetic acid and trichloroacetic acid are fluctuating.The effect of coagulation strength is to shorten the time of rapid stirring,which has a better effect on the precipitation removal of TCM,1,1,1-TCP,1,1-DCP,DCAN and DCAA,but a worse effect on TCAA.Shortening the medium speed stirring time,the precipitation removal effect of TCM,1,1,1-TCP,1,1-DCP and DCAN is poor,the precipitation removal effect of DCAA and TCAA is good,especially the precipitation removal effect of DCAA is obviously different.With the increase of pH,the concentration of TCM decreased first and then increased.The concentrations of 1,1,1-TCP,1,1-DCP,DCAN,DCAA and TCAA decreased gradually,and the concentrations decreased little after pH is 8.With the increase of reaction temperature,the concentrations of TCM,DCAA and TCAA gradually increased,the concentrations of 1,1,1-TCP gradually decreased,and the concentrations of 1,1-DCP and DCAN first increased and then decreased.With the increase of potassium permanganate concentration,the concentrations of TCM,1,1,1-TCP,DCAA and TCAA gradually decreased,while the concentrations of 1,1-DCP and DCAN first decreased and then increased.With the increase of the dosage of preoxidant chlorine dioxide,the concentration of TCM decreased significantly when the concentration of chlorine dioxide was 0-1.5mg/l,from 45.11?g/L to 29.55 p,g/L,and the concentration of TCM tended to be stable with the increase of preoxidant concentration.With the prolongation of preoxidation time of potassium permanganate,the concentration of TCM first decreased and then increased,and then decreased to the lowest value at 40 min of preoxidation.The concentrations of 1,1,1-TCP,DCAN,DCAA and TCAA all decreased in varying degrees,while the concentrations of 1,1-dcp gradually increased but the overall change was not significant.With the prolongation of preoxidation time of chlorine dioxide,the concentration of TCM first decreased and then increased,the concentration of 1,1,1-TCP gradually increased,and the concentration of DCAN,1,1-TCP,DCAA and TCAA gradually decreased.With the increase of pH,the concentration of TCM decreased first and then increased.The concentrations of 1,1,1-TCP,1,1-DCP,DCAN,DCAA and TCAA decreased gradually.The concentration of TCM decreased first and then increased with the increase of pH.The concentration decreased by 33.07%from 34.59 ? g/L at pH 5 to 23.15 ? g/L atpH 7.