Factors controlling micropollutant removal during riverbank filtration

This article summarizes the results of Water Research Foundation report 3136, Removal and Fate of EDCs and PPCPs in Bank Filtration Systems. The efficiency of bank filtration (BF) as a water treatment process for removing organic trace pollutants in general, and more specifically pharmaceuticals and personal care products and endocrine disrupting compounds, was evaluated. Chemical structure and physicochemical properties of a compound, retention time, and redox setting were identified as key factors controlling removal of trace pollutants. Temperature and discharge of the river were found to be important for the minority of compounds investigated. Results obtained from a literature survey and from water utilities in the United States and Germany, but with different site characteristics and trace pollutant concentrations, were transferable. Concentrations of more than 70 detectable pollutants mostly decreased during bank passage. Persistent substances were mainly ethylenediaminetetraacetic acid (EDTA), sulfamethoxazole, carbamazepine, amidotrizoic acid, naphthalene-1,5-disulfonate, and naphthalene-1,3,5-trisulfonate.