Turning Waste into a Solution: Drinking Water Treatment Residuals as a Low-Cost Adsorbent for Antibiotic Removal

The presence of emerging contaminants, especially antibiotics, has raised global concern. One of the main sources of antibiotics into the environment is wastewater, which is why efforts have been made to introduce new treatment methods for the antibiotic’s removal. The use of drinking water treatment residuals (DWTR) as a low-cost adsorbent may become a sustainable option for removing antibiotics. The objective of this study was to analyse and explore the potential of DWTR as an adsorbent of sulfamethoxazole (SMX) and trimethoprim (TMP) in continuous flow conditions using a fixed-bed column. The breakthrough curves reveal differences between the antibiotic’s adsorption onto DWTR, which may be related to the compounds' electrostatic interactions and hydrophobic properties. DWTR showed better performance for TMP, with a removal efficiency of 51%, compared to 35% for SMX. This preliminary study highlights the potential of DWTR as a low-cost adsorbent for antibiotics, with adsorption capacities comparable to other low-cost options, without requiring any kind of activation or additional treatment.