LI Meng-yu,LIU Zhi,ZHANG Tian-yang,et al.Impact Factors of Monochloramine Formation Efficiency during Chloramination Disinfection[J].China Water & Wastewater,2021,37(3 3):38-44.
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Impact Factors of Monochloramine Formation Efficiency during Chloramination Disinfection

China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU] volume: 第37卷 Number: 3 3 Page: 38-44 Column: Date of publication: 2021-02-01
Author(s):
LI Meng-yu; LIU Zhi; ZHANG Tian-yang; XU Bin
(State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China)
Keywords:
chloramine disinfection; monochloramine; disinfection by-products; impact factor
Abstract:
Effects of nitrogen sources, mass ratio of chlorine to nitrogen, pH, reaction time, temperature, G value and chlorine dosing rate on monochloramine (NH2Cl) concentration and disinfection by-products (DBPs) production in filtered water were systematically investigated in a drinking water treatment plant in Shanghai. It was found that nitrogen sources, mass ratio of chlorine to nitrogen and pH were the main impact factors, while others were the secondary impact factors. Compared to other four kinds of nitrogen sources ［NH4Cl, (NH4)2CO3, NH4Ac, and NH3·H2O］, a higher concentration of monochloramine was produced when (NH4)2SO4 was the nitrogen source. When pH increased from 6.0 to 9.0, the concentration of NH2Cl (calculated by the amount of Cl2) increased from 2.611 mg/L to 4.256 mg/L. As the mass ratio of chlorine to nitrogen increased from 2 ∶1 to 8 ∶1, the concentration of NH2Cl increased first and then decreased, and it reached the maximum of 3.831 mg/L at 5 ∶1. The total concentration of DBPs increased with the increase of chlorine to nitrogen mass ratio, reaction time, temperature and chlorine dosing rate, and decreased with the increasing G value. However, DBPs concentration decreased first and then increased slightly as the pH value increased from 6.0 to 9.0. The optimum conditions for the formation of monochloramine in the chloramine disinfection process of the drinking water treatment plant were as follows: (NH4)2SO4 as the nitrogen source, Cl2/N mass ratio of 4 ∶1 to 5 ∶1, neutral or alkaline pH, reaction time of 2 h, temperature of 25 ℃, G value of 300 s-1 and low chlorine dosing rate.
Last Update: 2021-02-01