ZHANGMin,XUYing,MIAOYi,et al.Utilization of CT Value in Urban Sewage Chlorine Disinfection and the Impact of Phosphorus Removal Agents[J].China Water & Wastewater,2024,40(17):79-83.
Utilization of CT Value in Urban Sewage Chlorine Disinfection and the Impact of Phosphorus Removal Agents
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第17期
Page:
79-83
Column:
Date of publication:
2024-09-01
- Keywords:
- sewage treatment plant; disinfection; sodium hypochlorite; CT value; phosphorus removal agent
- Abstract:
- The concentration time product (CT value) serves as a practical criterion for guiding the disinfection process. Different CT values are typically associated with varying levels of microorganism removal following different disinfection methods, and the corresponding chlorine disinfection parameters for each sewage treatment plant can be determined based on CT values. The fitted CT value and the logarithmic removal rate of fecal coliforms were determined based on the total residual chlorine in the effluent, yielding a correlation coefficient of 0.8 for the CT value curve. Based on the fitted CT value curve, it was recommended to control the total residual chlorine in the effluent at 0.5 mg/L, and the effective chlorine concentration should be maintained within a range of 3-5 mg/L, so as to comply with the effluent fecal coliforms requirement of less than 1 000 count/L as stipulated in Discharge Standard of Main Water Pollutants for Municipal Wastewater Treatment Plant ＆ Key Industries of Taihu Area (DB 32/1072-2018). However, if the iron content of phosphorus removal agents exceeded 3%, it would hinder the disinfection performance of sodium hypochlorite. Therefore, sewage treatment plants using such phosphorus removal agents should appropriately increase the effective concentration of disinfectants.
Last Update:
2024-09-01