Agri-Environment Branch, Agri-Food and Bioscience Institute, Belfast, UK.
Food Research Branch, Agri-Food and Bioscience Institute, Belfast, UK.
J Environ Manage. 2022 Dec 15;324:116292. doi: 10.1016/j.jenvman.2022.116292. Epub 2022 Sep 30.
Passive samplers (PS) have been proposed as an enhanced water quality monitoring solution in rivers, but their performance against high-frequency data over the longer term has not been widely explored. This study compared the performance of Chemcatcher® passive sampling (PS) devices with high-frequency sampling (HFS: 7-hourly to daily) in two dynamic rivers over 16 months. The evaluation was based on the acid herbicides MCPA (2-methyl-4-chlorophenoxyacetic acid), mecoprop-P, fluroxypyr and triclopyr. The impact of river discharge parameters on Chemcatcher® device performance was also explored. Mixed effects modelling showed that time-weighted mean concentration (TWMC) and flow-weighted mean concentration (FWMC) values obtained by the HFS approach were both significantly higher (p < 0.001) than TWMC values determined from PS regardless of river or pesticide. Modelling also showed that TWMC values were more similar to TWMC than FWMC values. However, further testing revealed that MCPA TWMC values from HFS and PS were not significantly different (p > 0.05). There was little indication that river flow parameters altered PS performance-some minor effects were not significant or consistent. Despite this, the PS recovery of very low concentrations indicated that Chemcatcher® devices may be used to evaluate the presence/absence and magnitude of acid herbicides in hydrologically dynamic rivers in synoptic type surveys where space and time coverage is required. However, a period of calibration of the devices in each river would be necessary if they were intended to provide a quantitative review of pesticide concentration as compared with HFS approaches.
被动采样器 (PS) 已被提议作为一种增强型水质监测解决方案用于河流中，但它们在更长时间内针对高频数据的性能尚未得到广泛探索。本研究在 16 个月的时间里，比较了 Chemcatcher® 被动采样 (PS) 设备与高频采样 (HFS：每 7 小时至每天) 在两条动态河流中的性能。评估基于酸除草剂 MCPA（2-甲基-4-氯苯氧基乙酸）、Mecoprop-P、氟草烟和三氯吡。还探讨了河流流量参数对 Chemcatcher® 设备性能的影响。混合效应模型表明，HFS 方法获得的时间加权平均浓度 (TWMC) 和流量加权平均浓度 (FWMC) 值均显著高于 PS 确定的 TWMC 值（p < 0.001），无论河流还是农药。模型还表明，TWMC 值与 PS 值比 FWMC 值更相似。然而，进一步的测试表明，HFS 和 PS 获得的 MCPA TWMC 值没有显著差异（p > 0.05）。几乎没有迹象表明河流流量参数改变了 PS 的性能——一些较小的影响不显著或不一致。尽管如此，PS 对极低浓度的回收率表明，Chemcatcher® 设备可用于在需要空间和时间覆盖的同步类型调查中评估水文动态河流中酸除草剂的存在/不存在及其大小。然而，如果它们旨在与 HFS 方法相比提供对农药浓度的定量评估，那么在每个河流中对设备进行校准的时间段是必要的。
