沱江三氯甲烷浓度异常事件中污染物趋势分析

Pollution Trend Analysis of Trichloromethane Water Environmental Events in Tuojiang River

以“2.19”沱江下游段三氯甲烷浓度异常事件为例,“污染物”为主线,通过对特征污染因子、污染源的锁定及污染物扩散状况的研判建立应急监测工作方案,确定主要污染物为三氯甲烷,对三氯甲烷浓度变化趋势进行分析。结果表明:各监测断面三氯甲烷浓度随时间变化逐步降低,监测到饮用水源地污染物持续未检出。各断面随污染团下移三氯甲烷污染物通量呈下降趋势。单一断面通量浓度先升高后降低;相邻断面通量浓度平稳下降,衰减力度逐渐放缓。通过一维河流水质模型计算结果,表明监测数据合理。该实例可为相关突发水环境事件的应急监测工作提供技术参考。

Taking the trichloromethane pollution event in the downstream section of‘2·19’Tuojiang River as an example,a work programme for emergency monitoring was established throughthe determination of major pollution factors,the determination of pollution sources and the judgement of pollutant dispersion.Determination of main pollutants as trichloromethane,the change trend of trichloromethane concentration in emergency monitoring was analyzed.The results show thatthe trichloromethane concentration in monitoring section decreased gradually with time and contaminants in drinking water sources have not been detected.The trichloromethane flux of each section decreased with the downward movement of the pollutant.The flux concentration of single cross section increased first and then decreased,adjacent sections decreased steadily and the attenuation gradually slowed down.The results of one-dimensional river water quality model show that the monitoring data are reasonable.This case can provide technical reference for emergency monitoring of relevant water environmental emergencies.