Development of a commercial sorbent adsorption process for the removal of pharmaceuticals from municipal wastewater with subsequent chemical regeneration

Our research is part of the MAR2PROTECT project which aims to enable an innovative controlled aquifer recharge (MAR) by reusing effluents from municipal wastewater treatment plants, but high-purity water is needed. Pharmaceuticals in wastewater, even at low concentrations (ng/L-μg/L), pose risks due to persistence and bioaccumulation, contributing to health problems. Current treatments are insufficient, and only Directive (EU) 2024/3019 mandates an 80% reduction of certain drugs by 2035. To address this, we aim to develop a cost-effective, sustainable quaternary treatment for removing pharmaceuticals, aligning with MAR2PROTECT guidelines. Adsorption was chosen for its simplicity, flexibility, and efficiency at low concentrations. We tested carbamazepine, clarithromycin, ibuprofen, and diclofenac, selected based on their prevalence in wastewater, using Directive (EU) 2024/3019 as a reference. Two commercial adsorbents, AmberLite™ XAD™16N and GAC Norit 1240 W, were evaluated. To reduce costs and enhance sustainability, we incorporated chemical regeneration and evaluated solvent recovery via evaporation for future adsorption-desorption cycles. Rapid tests identified the most cost-effective solvent for each adsorbent, followed by breakthrough tests (BTs) to assess adsorption performance, with subsequent regeneration using the best solvent. XAD16N showed excellent adsorption yields and high-water treatment capacity, with ethanol emerging as the best and most economical regeneration solvent, even with evaporation recovery. Norit was tested in rapid tests and partially in BT test, showing good drug removal and water treatment capacity, with slightly better carbamazepine and lower diclofenac retention. However, its chemical regeneration in rapid tests was poor, with 2-propanol performing marginally better. Both materials remove pharmaceuticals effectively, but Norit’s final test results are needed for definitive conclusions.