Abstract

The aim of this study is to understand the spatial and seasonal variations of persistent herbicides metabolites and to determine their origins in the Vilaine River watershed, Britany-France. Improving knowledge on herbicides metabolites sources and seasonality is important for drinking water resource management. Data were collected at 13 sampling stations during five sampling campaigns in 2016 and 2017. Relations between water quality parameters, herbicides and metabolites were analyzed using statistical methods. The influence of land use and wastewater treatment plants (WWTP) on streams water quality has been identified. Cluster Analysis revealed that two groups of sampling stations can be described as “urban” with stations downstream the urban area and as “agricultural” with stations located downstream of the watershed. Chloroacetamids metabolites have been associated together with nitrates and agricultural areas as could be expected. Thus, the drinking water treatment plant located in the estuary of the Vilaine River is exposed to high metolachlor ESA and nitrate loads all year long. Aminomethylphosphonic acid (AMPA) is associated to anthropogenic urban contamination and nutrient loads. AMPA has its major sources in both glyphosate and phosphonate detergents issued from WWTP. This can help to adapt surface water treatment process and water management policies concerning herbicides metabolites.

 抽象的

本研究的目的是了解持久性除草剂代谢物的空间和季节变化，并确定其在法国布列塔尼维莱讷河流域的起源。提高对除草剂代谢物来源和季节性的了解对于饮用水资源管理非常重要。在2016年和2017年的五次采样活动中，在13个采样站收集了数据。采用统计方法分析了水质参数、除草剂和代谢物之间的关系。土地利用和废水处理厂 (WWTP) 对溪流水质的影响已经确定。聚类分析显示，两组采样站可描述为“城市”（采样点位于市区下游）和“农业”（采样点位于流域下游）。正如预期的那样，氯乙酰胺代谢物与硝酸盐和农业领域有关。因此，位于维莱讷河口的饮用水处理厂全年都暴露在高异丙甲草胺 ESA 和硝酸盐负荷下。氨甲基膦酸 (AMPA) 与人为城市污染和养分负荷有关。 AMPA 的主要来源是污水处理厂提供的草甘膦和膦酸盐洗涤剂。这有助于调整地表水处理工艺和有关除草剂代谢物的水管理政策。