Analysis of emerging contaminants in sewage effluent and river water: comparison between spot and passive sampling

Abstract

Passive sampling is highly complimentary to spot sampling in environmental analysis. A polar organic chemical integrative sampler (POCIS) was extensively tested to optimize its performance under both controlled and field conditions. The passive sampler was subsequently used for the sampling and analysis of estrone, 17beta-estradiol, 17alpha-ethynylestradiol, bisphenol A, propranolol, sulfamethoxazole, meberverine, thioridazine, carbamazepine, tamoxifen, indomethacine, diclofenac and meclofenamic acid in sewage effluent and river water. Under laboratory conditions, the kinetics of compound uptake by POCIS were linear during 10-day of exposure. POCIS sampling rates of the target compounds were significantly greater by using polyethersulfone instead of polysulfone membrane, and enhanced with increasing sorbent exposure area. Together with spot water sampling, the optimized POCIS was deployed in the River Ouse, West Sussex, UK to obtain field-derived sampling rates which, for endocrine disrupting chemicals (EDCs), were significantly higher than those from laboratory experiments. Both spot and passive sampling demonstrated that most of the target chemicals were frequently detected in sewage effluent and river waters, and that the daily changes in the pollutant concentrations were greater for pharmaceuticals than for EDCs. The aqueous concentrations of all compounds were elevated at a sewage outfall, which is confirmed to be an important source of the target compounds in the river. The validated POCIS was then successfully used to estimate the concentrations of the target compounds in effluent and river water, which were in good agreement with those from spot sampling for pharmaceuticals.