Removal of SARS-CoV-2 Antivirals from Aqueous Media Using Bioaugmented Activated Sludge

This study investigated the removal of SARS-CoV-2 antivirals substances (SASs) in wastewater treatment systems through kinetic analysis and response surface modeling based on a full factorial experimental design (3³). Quadratic models best described the removal of most SASs, revealing nonlinear interactions among experimental factors and identifying the SASs mixture ratio as the key determinant of removal efficiency. Based on their removal behavior, the investigated SASs were classified into three groups: reversible adsorption (FAV, REM), enhanced bioavailability (DCV, DRV) and irreversible adsorption (LOP, RIT). LOP and RIT exhibited the highest adsorption affinities and formed the initial layer on activated sludge, whereas the limited removal of DRV and FAV reduced the overall treatment efficiency. The increased bacterial Colony-Forming Unit (CFU) suggests enhanced microbial activity, which may have promoted extracellular polymeric substance (EPS) production, contributing to reduced toxicity toward Aliivibrio fischeri. Finally, integrating RSM-derived polynomial models with artificial intelligence offers a promising approach for predicting and optimizing the removal of SARS-CoV-2 antivirals in conventional wastewater treatment plants.