Study of Adsorption Efficiency of Lignite, Biochar, and Polymeric Nanofibers for Veterinary Drugs in WWTP Effluent Water

Abstract

The increased consumption, overuse, and subsequent difficult removal of pharmaceuticals using conventional processes lead to their rising prevalence in the environment. Adsorption belongs to the most efficient approaches to pharmaceuticals’ removal from wastewater. This study provides insight into the sorption properties of biochar, lignite, and polyamide nanofibers (PA-nanofibers) for sulfamethoxazole, trimethoprim, clarithromycin, azithromycin, and amoxicillin in ultrapure and wastewater treatment plant (WWTP) effluent water. The negative effect of WWTP effluent water was reflected in a reduction of the sorption capacity of biochar by 6.31–72.15%, 25.58–98.55% for lignite, and 4.21–67.71% for PA-nanofibers. Simultaneously, this study investigates the impact of the experimental setup. The sorption capacities were recorded in the range from 0.65 to 2.84 mg g−1 for biochar, 0.04 to 75.73 μg·g−1 for lignite, and 0.53 to 30.54 μg·g−1 for PA-nanofibers during the fixed-bed column tests with WWTP effluent water. Based on the results, biochar appears to be a suitable sorbent for selected pharmaceuticals in field conditions with running water. Lignite and PA represent complementary treatment technology or can act as a carrier for microbial degraders. Performed batch tests with ultrapure and WWTP effluent water and subsequent column tests highlighted the importance of conducting tests with the appropriate matrix and experimental setup to gain a realistic insight into the behavior of the sorbents under environmentally relevant conditions. Graphical Abstract