基于紫外可见吸收光谱微型污染溯源站的村镇水环境监测技术研究

为实现村镇分散度高、随机性强的水环境污染的高效管控，采用以紫外可见吸收光谱技术为核心的微型污染溯源站，于2022年4月1—14日对某县域村镇的河流水环境开展了在线监测溯源研究。结果表明，监测期间共发生2组污染事件，微型污染溯源站快速响应，氨氮、电导率等常规指标之间具有较强的相关性，各指标中，氨氮受冲击波动最为显著，最适合用于污染事件报警。通过紫外可见吸收光谱可识别污染事件之间的差异，第1组污染事件光谱特征为205 nm波长吸光度下降，疑似为硝态氮浓度下降；第2组污染事件光谱特征为230 nm波长出现显著吸收峰，疑似为水中烯-酮共轭双键类有机污染物含量大幅增加。多元线性回归拟合结果表明，2组污染事件可能分别由污水处理厂工艺波动导致的超标排放和上游化工类企业的偷排造成。研究结果为微型污染溯源站实现对不同污染情景的报警和溯源提供了依据。

Study on Monitoring Technique in Rural Water Environment Based on Pollution Tracing Micro Station

Water pollution in villages and towns has strong dispersion and high randomness. In order to realize the efficient management and control, this paper adopted the pollution tracing micro station (PTMS) technology with UV Vis absorption spectrum as the core, and continuous monitoring was conducted on the pollution collecting river of a county from 1st to 14th, April, 2022. The research on the two groups of pollution incidents that occurred during the epidemic control period found that PTMS responded quickly after incidents occurred. There was a strong correlation between conventional indicators such as ammonia nitrogen and electrical conductivity, which played an effective and timely alarming role. But conventional indicators could not distinguish the two groups of pollution events, while the difference between pollution events can be identified by UV Vis absorption spectrum. The first group of pollution events was characterized by the decrease of absorbance at 205 nm wavelength, and the second group of pollution events was characterized by the significant absorbance peak of 230 nm wavelength. Through spectrum database comparison, it was found that the two groups of pollution events indicated by the absorption spectra were the reduction of nitrate nitrogen and the increase of ene ketone conjugated organic matter. The development process of each pollution event was studied, analyzed and compared by regression fitting. The results showed that the two groups of pollution incidents might be caused by the process fluctuation of sewage treatment plants and the illegal discharge of chemical industrial enterprises, respectively. The PTMS with UV Vis absorption spectrum as the core can realize the alarm and traceability of different pollution scenarios.