Research On Controlling Technologies Of Odor Caused By Drinking Water Disinfection

As the source water of C city, the water quality pollution of D River is more serious, ammonia-nitrogen and chemical oxygen demand of the water plant effluent are high. Adopting chlorine disinfection causes that the amount of chlorinated disinfection by-products generated is high, tap water tastes bad and still exists unpleasant odor after boiling. Therefore from the side of disinfection, the research on control technology to the odor of the tap water is very meaningful.The paper has researched the odor of ozone-activated carbon effluent under different disinfection methods, at the same time in order to ensure chemical safety of drinking water, the experiment investigated on the situation of disinfection by-products generated. The different disinfection methods adopt by the experiment are common disinfection (sodium hypochlorite disinfection; chloramine disinfection; chlorine dioxide disinfection), sequential chlorination, associated chlorine dioxide and sodium hypochlorite disinfection, associated UV and chlorine dioxide disinfection, associated UV and chloramine disinfection. The results indicate that chloramine disinfection, sequential chlorination and associated chlorine dioxide and sodium hypochlorite disinfection (dosing concentration ratio for 1:3) can effectively control the taste and odor, as well as the generated amount of chlorinated disinfection by-products. The chlorine dioxide can reduce the amount of chlorinated disinfection by-products, but will increase the chroma of drinking water. In addition, the experiment has compared the impact of various water treatment processes on odor and the amount of chlorinated disinfection by-products in drinking water, the result shows that preozonation process + conventional process ( coagulation + sedimentation + filtration ) + ozone-activated carbon process + chloramine disinfection process (associated UV and chloramine disinfection process) can improve the odor of drinking water and reduce the generated amount of chlorinated disinfection by-products.The paper also studied the relationship between residual chlorine concentration and the odor of drinking water while the chlorine disinfection was used. The result shows that the value of drinking water odor is gradually reducing with the reduction of residual chlorine concentration. When the water supply pipeline is long, booster chlorination can reduce the amount of disinfectant dosing in the water plant, at the same time achieve the purpose of improving the water odor. This experiment also uses pipeline water quality stability analysis experimental device to simulate the actual pipeline, investigating the effect of pipeline biofilm and residual chlorine concentration to the taste and odor of drinking water when sodium hypochlorite disinfection, chloramine disinfection and chlorine dioxide disinfection were used. The results indicate that: pipeline biofilm compared with the residual chlorine concentration has little effect on improving the taster and odor of the disinfected water. In order to improving the taster and odor of the disinfected water, the residual concentration of sodium hypochlorite, chlorine dioxide and chloramine in the effluent of plant water should be controlled respectively under1.4mg/L, 0.7mg/L, 1.0mg/L.