Multi-site nanocomposite sorbent for simultaneous removal of diverse micropollutants from treated wastewater

Despite the advantages of maximizing treated wastewater (TWW) reuse, this practice brought upon the presence of micropollutants in edible plants, animals, and even humans, since many micropollutants are not completely removed by conventional treatment plants. Clay polymer nanocomposites (CPNs) have been proposed and widely studied in recent years as a promising sorbent for micropollutant removal. However, most of these studies report the development of a single CPN for the removal of specific micropollutants in batch experiments, usually from synthetic water, and do not compare to the removal by commercial sorbents. Here, we thoroughly investigated the adsorption mechanism of three chemically-diverse micropollutants; cationic, anionic, and non-ionic (metoprolol, diclofenac, and lamotrigine, respectively) from TWW by a CPN with a ‘loopy’ polymer configuration. The results suggest that both cation and anion exchange sites coexist on the CPN, and therefore anionic and cationic micropollutants adsorb simultaneously, and they do not compromise the adsorption of each other. The adsorption of the non-ionic micropollutant enhanced in the presence of the charged micropollutants due to a synergistic effect. These adsorption trends were also obtained for micropollutant filtration by CPN columns. Finally, we demonstrated the simultaneous filtration of effluent organic matter and an array of micropollutants from TWW by the CPN columns and compared it to the filtration by granular activated carbon (GAC). A cost-effective comparison indicates that the filtration by the CPN column is more efficient (ng pollutants/ sorbent cost) than by the GAC column.