白马河流域除草剂及其代谢产物的时空分布特征与生态风险评价  

Spatio-Temporal Distribution and Ecological Risk Assessment for Herbicide and Its Metabolites in Baima River

作　　者：叶敦雨 孙小银[1,2] 赵忠强 孙佳瑶 Ye Dunyu;Sun Xiaoyin;Zhao Zhongqiang;Sun Jiayao(Geography and Tourism College,Qufu Normal University,Rizhao,Shandong 276826,China;Key Laboratory of Nansihu Lake Wetland Ecological and Environmental Protection,Rizhao,Shandong 276826,China)

机构地区：[1]曲阜师范大学地理与旅游学院,山东日照276826 [2]南四湖湿地生态与环境保护山东省高校重点实验室,山东日照276826

出　　处：《水土保持通报》2022年第3期74-81,共8页Bulletin of Soil and Water Conservation

基　　金：山东自然科学基金项目“南四湖流域地表水农药污染对土地利用及其景观格局的响应机制研究”(ZR2021MD088)。

摘　　要：[目的]探讨典型除草剂阿特拉津(ATR)及其代谢产物脱乙基阿特拉津(DEA)、脱异丙基阿特拉津(DIA)在作物生长季(6—9月)的污染特征以及时空变化,为农业小流域除草剂的管理、使用与保护决策提供科学依据。[方法]在白马河流域沿程设立18个采样点,基于实地监测和室内分析,探讨污染物的时空变化特征,并运用熵值法进行生态风险评价。[结果](1)所有采集水样中均有ATR及代谢产物检出,其中ATR在6—7月的地表水样中100%检出,8—9月检出率稍有下降,代谢产物DEA,DIA在前两月检出率较低,后两月检出率增加。(2)白马河污染物空间分布表明,各污染物浓度最高值大多出现于河流上游和中游,下游浓度均相对较低。这可能与河流下游河道宽阔、水流量大、稀释作用较强有关。(3)生态风险评价结果显示ATR,DEA和DIA风险等级均为中等,其原因是该河流的水负荷低,稀释能力不足。[结论]相对于大流域,白马河作为典型农业流域的小支流,水量小、稀释能力不足,造成污染的生态风险高于许多大流域。[Objective] The spatio-temporal variations of a typical herbicide(atrazine,ATR) and its degradation products [deethylatrazine(DEA) and deisopropylatrazine(DIA)] during the crop growing season(June to September) was investigated in order to provide scientific supports for management,usage,and protection of herbicides in a small agricultural watershed.[Methods] Eighteen sampling sites were designated along the Baima River,and the spatio-temporal dynamics of pollutants were obtained through the combined methods of field monitoring and lab analysis.Ecological risk was evaluated by the risk of herbicides quotient method.[Results](1) ATR and its metabolites were detected in all of the collected water samples.ATR detection rates in surface water samples in June and July were higher than those in August and September.However,the detection rates of metabolites including DEA and DIA were low in the first two months and increased in the later two months.(2) The spatial distribution of herbicide pollution in the Baima River showed that the maximum values of pollutants mainly occurred in the upper and middle reaches of the river.The concentration levels in the lower reaches were relatively low,which may be attributed to the wide river channel,large water flow,and strong dilution effect in the lower reaches of the river.(3) The risk levels of ATR,DEA,and DIA for the entire river were all at the moderate level due to low water load and insufficient dilution capacity of the river.[Conclusion] Compared with larger watersheds,the Baima River,as a small tributary of typical agricultural watersheds,has small water volume and insufficient dilution capacity that results in higher ecological pollution risks than many larger basins.

关 键 词：阿特拉津 代谢产物 农业小流域 生态风险评价 

分 类 号：X171.5[环境科学与工程—环境科学]