Passive Sampling Devices for Long-Term Monitoring of Dissolved Hydrophobic Contaminants in River Water

Abstract

Long-term monitoring of dissolved hydrophobic contaminants in river water is essential for assessing environmental pollution, ecological risk, and the effectiveness of water quality management strategies. Conventional grab sampling methods often fail to accurately represent fluctuating contaminant concentrations due to temporal variability and low detection sensitivity. The present study investigates the application of passive sampling devices for long-term monitoring of dissolved hydrophobic contaminants in river water under varying environmental conditions. The research focuses on evaluating sampling efficiency, contaminant uptake behavior, calibration performance, and analytical reliability associated with passive sampling technologies. Experimental analysis was conducted to examine the influence of water flow conditions, exposure duration, temperature, biofouling, and contaminant physicochemical properties on sampling rates and accumulation efficiency. Results demonstrate that passive sampling devices effectively accumulate hydrophobic organic contaminants over extended monitoring periods, enabling improved detection of trace-level pollutants and time-integrated concentration assessment. The study further reveals that optimized deployment duration and membrane characteristics significantly enhance sampling sensitivity and reproducibility while minimizing analytical uncertainty. Comparative assessment with conventional water sampling methods confirms the advantages of passive samplers, including reduced sampling frequency, lower operational costs, and improved representation of long-term contaminant exposure conditions. In addition, the technology demonstrated strong applicability for monitoring persistent organic pollutants and industrial contaminants in dynamic river environments.