三氯异氰尿酸在窖水中的余氯衰减规律及消毒效果

Decrease behavior of residual chlorine and disinfection efficacy of trichloroisocyanuric acid in cellar water

为保持集雨窖水水质,提高饮用水安全性,采用向窖水中投加三氯异氰尿酸(trichloroisocyanuric acid,TCCA)的消毒方法,检测主体水的余氯衰减规律和微生物的变化情况,重点研究了消毒剂投加量、温度及pH等因素的影响。实验结果表明:余氯衰减过程符合一级动力学模型;随初始氯投加量的增大,水中余氯衰减量增大,余氯衰减系数减小且与初始投加量的倒数成线性正相关;随水中有机物等反应物浓度的降低,余氯衰减量减少,余氯衰减系数减小;随温度的升高,余氯衰减量增大,衰减系数增大;随pH的增大,余氯衰减量减少,衰减系数减小;水中菌落总数的灭活率随消毒剂投加量的增加而增大。当消毒剂浓度为1.5~2.5 mg·L-1时,在60 min内可完成对菌落总数99.0%的灭活;当消毒剂浓度大于2.5 mg·L-1时,在30 min内可完成对菌落总数99.9%的灭活。在pH为6~9时,pH越小,消毒效果越好;在10~30℃时,温度越高,消毒效果越好;水中氨氮存在时,氯胺的生成会减弱短期消毒效果。与传统氯制消毒剂相比,TCCA在窖水消毒方面有较好的应用前景。

In order to maintain the quality and improve the safety of drinking water,a disinfection method of adding trichloroisocyanuric acid(TCCA) to the cellar water was employed.In this study,the residual chlorine decay law and microbial changes in the bulk water was detected,and the effects of disinfectant dosage,temperature and pH on the process were mainly focused on.The results showed that the residual chlorine decay process accorded with the first-order kinetic model.With the increase of the initial chlorine dosage,the amount of residual chlorine attenuation in the water increased,the residual chlorine attenuation coefficient decreased and was positively and linearly correlated with the reciprocal of the initial dosage.With the decrease of reactants such as organic matter in the water,the residual chlorine attenuation and coefficient decreased.Increase of temperature also led to the increase of the residual chlorine attenuation and coefficient.However,both the residual chlorine attenuation and coefficient decreased when pH increased.The inactivation rate of the total number of colonies increased with the increase of disinfectant dosage.The inactivation rate reached 99.0% within 60 min when the concentration of disinfectant was 1.5~2.5 mg·L-1,and 99.9% within 30 min when the disinfectant concentration was over 2.5 mg·L-1.In the range of pH 6~9,the smaller the pH,the better the disinfection efficacy;in the range of 10~30 ℃,the higher the temperature,the better the disinfection efficacy.In the presence of ammonia nitrogen,the formation of chloramine weakened the short-term disinfection efficacy.Compared with traditional chlorine disinfectants,TCCA has a preferable application prospect in cellar water disinfection.