Study On Chlorine Disinfection Methods Of Raw Water In Huangpu River With Advanced Treatment Process

The traditional disinfection just aim at pathogeny microorganism in raw water. Its objective is kill the pathogeny microorganism as sufficiency as possible to make sure the safety of drinking water. For the reasons in the front, to ensure the drinking water safety must recognition the minim DBPs harmful to our body in a long period of time in drinking water, not simply think over the problem of microorganism safety. It means that the research of disinfection should both control microorganism and DBPs rather than microorganism simply. And contemporary, we should think over the microorganism stability and chemistry stability in the pipe net caused by disinfection.The raw water of the Third Water Works of Minhang Water Supply Company is pumped from the water of Huangpu River in the head part. It is treated by O₃-BAC advanced process. According to the date of pilot-scale test before, the COD_Mn value of effluent is 2.65mg/L, the average value of ammonia nitrogen is 0.21mg/L. this research mainly study on the effluent water quality of chloramine disinfection and break-point chlorine (free chlorine) disinfection, compare the effect of this two disinfection process, the quest for the parameters of running and infection factors. The finally objective is to find out a rational disinfection process for the running advanced process to consult.On the basic of analysis the application of chorine disinfection of both domestic and abroad, integrated the water quality of water in the head of Huangpu River and fact of production, we carry out some useful search by pilot-scale test and lab experiment with the process of chloramine and free chlorine disinfection. The conclusions are as flow:Chloramine disinfection is all right and economy while the ammonia nitrogen concentration upwards 1mg/L. Chloramine and break-point disinfection are both all right while the ammonia nitrogen concentration among 0.5-1 mg/L. But break-point chlorine disinfection maybe makes the water smelly. Chloramine disinfection is a better choice. There will not be enough chemical combination chlorine for disinfection while adapt chloramine disinfection under the ammonia nitrogen concentration lower than 1mg/L.The ratio of residual chlorine attenuation by chloramine is lower than the free chlorine, and the continuance disinfection of chloramine is better than the break-point chlorine (free chlorine) disinfection.The ability of sterilization of chloramine is feebleness than free chlorine. For the ozone dosed in the advanced water treatment process can kill lot of microorganism, the total number of bacterial colony of effluent from BAC is lowness, so the effluent from disinfection by the two process is more or less the same.In the condition of pledge the safety of microorganism, the kinds of DBPs produced by chloramine is less than break-point chlorine. The total trihalomethane produced by chloramine is 1.67μg/L, the total haloacetic is 9.84μg/L. The taste of water disinfected by chloramine is worse than chlorine disinfection said by some expert. The total trihalomethane produced by break-point chlorine disinfection is 9.23μg/L, the total haloacetic is 22.79μg/L. The value of both trihalomethane and haloacetic are in the scope of Health Standard for Domestic Drinking Water, for the reason that the premonitory material of DBPs was preferably treated by advanced treatment.Chlorine disinfection influences the microorganism stability of drinking water clearly. The higher the concentration of free chlorine is, the worse the microorganism stability. Chloramine disinfection does better than free chlorine disinfection in reducing the AOC value and heightens the microorganism stability.In the finality, the problems requiring further studies are discussed.