Nanofiltration of hormones and pesticides in different real drinking water sources

► Ultrafiltration did not affect the ionic composition and total organic carbon in the water. ► Nanofiltration efficiency was often not strongly affected by static and dynamic preadsorption. ► High percent rejections obtained for the pesticides and hormones. ► Percent rejections were often independent of the water composition. ► Size exclusion and hydrophobic interactions were found to highly influence the rejections. This study addresses the efficiency of nanofiltration to remove different pesticides and hormones from different real water sources (surface water and groundwater) and the effect of the ionic composition of different water sources on the rejection of the target micropollutants. Ultrafiltration was performed prior to the nanofiltration process to remove particulate and large colloidal organic matter, that interfere in the rejection of micropollutants during nanofiltration, without affecting the concentration of ionic species and natural organic matter present in the water. The other aim of this study was to understand the role of adsorption on the rejection of the solutes selected, which was tested by conducting membrane pre-adsorption experiments using these micropollutants under static and dynamic conditions. High percent rejections (67.4–99.9%) were obtained for the pesticides and hormones, often independently of the water composition. Size exclusion and hydrophobic interactions were found to highly influence the rejections obtained. The lower rejections (57.5–83.5%) obtained for pentachlorophenol could be explained by its increased solubility at the waters’ pH. The overall nanofiltration efficiency to remove the selected compounds was not found to be considerably affected by the pre-adsorption of the compounds on the membrane under static and dynamic conditions, except for 17α-ethinylestradiol, estrone, and estriol in surface water.