Study of the rejection of contaminants of emerging concern by a biomimetic aquaporin hollow fiber forward osmosis membrane

Abstract

Forward osmosis (FO) plays an increasingly important role in membrane processes because of its advantages compared to traditional pressure-driven membrane processes. There are different types of water-selective FO membranes. In this study, a biomimetic hollow fiber module comprising an active layer of polyamide thin film composite (TFC) with integrated aquaporin proteins and an effective area of 0.6 m2 is used to study the rejection of 24 Contaminants of Emerging Concern (CECs). The rejections obtained for all the contaminants studied were higher than 93 % and for 19 of them rejections of up to 99 % were reached. It was observed that although all the tested compounds showed rejections very close to 100 %, they were not completely recovered in the feed solution which makes the retention within the membrane an important factor to be considered. Hence, two membrane rinses were necessary after each membrane operation to completely recover each contaminant. The results were analyzed considering the physicochemical properties (molecular weight, charge and hydrophobicity) of the contaminants.