Validation and application of diffusive gradient in thin-film (DGT) equipped novel cyclodextrin polymer gels for monitoring endocrine disrupting chemicals (EDCs) and environmental risk assessment in the Taihu lake basin

Abstract

Taihu Lake is the most important drinking water source of the major cities in the Yangtze River Delta. The pollution of endocrine disruptors (EDCs)in Taihu Lake has been increasing recently, the accurate determination is an important guide for predicting its health risks and developing appropriate controls. Monitoring organic pollutants in water using the diffusive gradient in thin film technique (DGT) has attracted much attention due to more accuracy and convenience than the grab sampling methods. In this study, a novel cyclodextrin polymer (CDP) synthesized by the simple and green method in water was taken as an adsorbent for the binding gel. Four endocrine-disrupting chemicals (EDCs), bisphenol A (BPA), 17α-ethinylestradiol (EE2), 17β-estradiol (E2), and estriol (E3), were taken as models to determine the diffusion coefficients (4.68 × 10−6, 3.38 × 10−6, 3.34 × 10−6 and 4.31 × 10−6 cm2/s) and to test the performance of DGT, such as adsorption capacity and deployment time (1–5 day). The assembled CDP-DGT was adopted to determine four EDCs in a simulated water environment (3–9 of pH, 0.001–0.5 M of ionic strength (IS), and dissolved organic matter (DOM) of 0–20 mg/L). The ability of CDP-DGT sampling was verified in the Jiuxiang River and was carried out for a large-scale field application of in situ sampling EDCs in Taihu Lake basin. The results show that the total EDCs concentration range and the estradiol equivalent concentrations (EEQ) in Taihu Lake and its main rivers are 2.78 ng/L to 11.08 ng/L and 2.62 ng/L to 10.91 ng/L, respectively. The risk quotients (RQs) of all sampling sites in the region were greater than 1, indicating that EDCs pose a serious threat to aquatic organisms in the area. Therefore, the monitoring of EDCs in the Taihu Lake basin should be further strengthened.