Liu Shao-Gang, Zhu Zhi-Liang, Han Chang, Qiu Yan-Ling, Zhao Jian-Fu
State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China.
Huan Jing Ke Xue. 2009 Sep 15;30(9):2543-9.
The model of second-order reaction kinetics has been used to fit the monochloramine decay in water samples by nonlinear imitation. Several factors were investigated, including pH, temperature, carbonate, bromide, iodide concentrations and natural organic matters in this system. The results showed that pH value was an important factor on the monochloramine decay rate, especially when pH was below 7.0. Temperature and carbonate levels also had obvious effect on the monochloramine decay. Co-existence of bromide anions had different impact under different pH values. At pH 6.60, monochloramine decay rate tended to decrease dramatically with the increment of bromide levels. However, when pH was above 7.60, 0.1 mg/L of bromide hardly affected the decay rate of mononchloramine. Co-existence of iodide showed stronger effect on the decline rate of monochloramine than that of bromide. It was demonstrated that the second-order kinetic model could fit well the experimental results of monochloramine decay reaction under the conditions of bromide or iodide co-existence. The results of this study will be of benefit to the theory and technology of drinking water disinfection, especially for the reduction of DBPs and the control of disinfectant dosages in the area of coastland and estuary.
采用二阶反应动力学模型，通过非线性模拟对水样中一氯胺的衰减进行拟合。研究了该体系中的几个因素，包括pH值、温度、碳酸盐、溴化物、碘化物浓度以及天然有机物。结果表明，pH值是影响一氯胺衰减速率的重要因素，尤其是在pH值低于7.0时。温度和碳酸盐水平对一氯胺的衰减也有明显影响。溴离子的共存在不同pH值下有不同影响。在pH 6.60时，一氯胺的衰减速率随着溴化物浓度的增加而显著降低。然而，当pH值高于7.60时，0.1 mg/L的溴化物对一氯胺的衰减速率几乎没有影响。碘离子的共存对一氯胺衰减速率的影响比溴离子更强。结果表明，在溴化物或碘化物共存的条件下，二阶动力学模型能够很好地拟合一氯胺衰减反应的实验结果。本研究结果将有助于饮用水消毒的理论和技术发展，特别是在沿海和河口地区减少消毒副产物以及控制消毒剂用量方面。
