海河流域滹沱河冲洪积扇地下水中农药污染及分布特征

地下水是海河流域滹沱河冲洪积扇重要的饮用水水源,农业种植过程中施用的农药会导致地下水污染,该地区地下水中农药的污染调查工作相对匮乏。为了研究滹沱河冲洪积扇地下水中农药的污染及分布特征,本文利用气相色谱-质谱联用技术分析了30组地下水样品中75种农药组分,用统计学方法对结果进行分析。结果显示:30个采样点中均有农药检出,检测的75种农药中检出40种,有机氯、有机磷、有机氮三类均有检出。检出率最高的为3-羟基呋喃丹(93.3%)、敌杀磷(90.0%)、地茂散(90.0%),30个样品检出浓度之和最大的为呋喃丹(4860.6ng/L)。研究区内三类农药平均检出浓度有机氯(70.8ng/L)有机磷(392.7ng/L)有机氮(580.9ng/L),这主要与三类农药的使用历程和性质相关:有机氯类农药由于其高毒、难降解等特性在1983年被禁用;21世纪初,相对高效、易降解的有机磷类和有机氮类农药应用广泛。三类农药的空间分布特征为从冲洪积扇顶部到中部,农药含量逐渐减少,这主要受冲洪积扇水文地质特征的影响。研究区内HCHs来源为近期林丹使用或HCHs工业降解,DDTs来源为新DDT源的释放或历史上的使用。研究结果可为我国地下水农药的污染监测和地下水相关标准制定提供数据支撑。

Pollution and Distribution Characteristics of Pesticides in Groundwater in the Alluvial-Pluvial Fan of the Hutuo River, Haihe River Basin

BACKGROUND: Groundwater is the primary drinking water source in the alluvial-pluvial fan of the Hutuo River. Pesticides application during agricultural planting leads to groundwater pollution. The pesticide pollution investigation work of this area in groundwater is relatively scarce.
OBJECTIVES: To study the pollution and distribution characteristics of pesticides in groundwater collected in the alluvial-pluvial fan of the Hutuo River.
METHODS: Gas Chromatography-Mass Spectrometry was used to analyze 75 pesticides in 30 groups of groundwater samples, and the results were investigated by statistical methods.
RESULTS: The results show that pesticides were detected in all 30 sampling sites. 40 of 75 pesticides were detected, which include organochlorine pesticides, organophosphorus pesticides, and organic nitrogen pesticides. The pesticides with the highest detection frequency were 3-hydroxycarburan (93.3%), dioxathion (90.0%) and chloroneb (90.0%). The pesticide with the maximum sum detection concentration of 30 samples was carbofuran (4860.6ng/L). The average detected concentrations of three pesticide types in the study area were 70.8ng/L for organochlorine pesticides, 392.7ng/L for organophosphorus pesticides, and 580.9ng/L for organic nitrogen pesti-cides, which is related to the application history and property of three pesticide types.
CONCLUSIONS: Organochlorine pesticides were banned in 1983 due to their high toxicity and hard degradation. At the beginning of the 21st century, relatively efficient and easily degradable organophosphorus pesticides and organic nitrogen pesticides developed rapidly. From the top to the middle of the alluvial fan, the concentration of the three pesticide types decreased gradually. The spatial distribution characteristics of pesticides were mainly influenced by the hydrogeological characteristics of the alluvial fan. HCHs in the area were from the recent using of lindan or industrial degradation of HCHs, DDTs were from the release of new DDT or historical ultilization. The research results provide basic data support for groundwater pesticides pollution monitoring and groundwater-related standard formulation in China.