Experimental Study On United Disinfection Mechanism Of Residual Chlorine And Chlorine Dioxide In Water Supply Network

Disinfect drinking water treatment has become an indispensable key step, it can be controlled by sterilization and killing of pathogenic microorganisms in drinking water, such as bacteria, viruses, protozoa, etc. Finished water chlorination, it can meet the national drinking water health standards generally. But after passing the treated water through the city pipe that a large and complex reactor, the pipe occurs in a series of physical, chemical and biological reactions, leading to decreased quality of drinking water, therefore, passing the treated water through the distribution network to reach the users, result in secondary pollution of drinking water and water quality does not meet the national drinking water standards. In China, the provisions of the latest drinking water health standards for drinking water health standards are the leading users, rather than water plant effluent water. Therefore, there is a big problem of drinking water quality in China's water security.Increase the amount of chlorine, to some extent, these problems can be solved, by maintaining a certain amount of chlorine to control pathogenic microorganisms in water re-growth and reproduction, however, chlorine disinfection generate carcinogenic, teratogenic, mutagenic disinfection by-products of chlorine (DPBs).Accordingly, this paper proposes combination disinfection of chlorine dioxide and chlorine in the pipe network, not only can reduce the production of toxic chlorine disinfection by-products, but also avoid the chlorine disinfectant in the pipe network decay too fast, can not guarantee the end of water pipe network security. In this paper, the experimental study on united disinfection mechanism of chlorine dioxide and chlorine, the influences of pipe materials and organic substances to decay of chlorine series disinfectants were studied. And the research on the kinetics of decay of chlorine series disinfectants was also systematically performed in this chapter. And study on the proportion of mixed disinfectant dosage optimization problem. In the dynamic test pipe, syudy on different flow rate on the decay of disinfectant, and verify the static test conclusions.The results show that chlorine dioxide and chlorine in the coupling mechanism, can enhance the effects of chlorine disinfection. And because of the different of pipe materials and pipe corrosion degree, the regularity of decay of chlorine series disinfectants is also different. Experiment found that the kinetics of chlorine series disinfectant degradation by pipe wall and organic substances followed complies with first order reaction equation respectively. By comparing lasting time of disinfectant, sterilization effect and yield of organic and inorganic disinfection by-products under different proportion, Obtained when the ratio of chlorine dioxide and chlorine for the optimal ratio of 3:1, the disinfectant will be best.In this study, we also verified the result by use of dynamic simulation distribution network, and obtain the same conclusion.