Adsorption and removal of seven antibiotic compounds present in water with the use of biochar derived from the pyrolysis of organic waste feedstocks

Abstract Biochars produced from various organic waste feedstocks have lately been utilized as adsorbents for the decontamination of antibiotics-contaminated environmental matrices. The aims of the present study were a) the assessment of the adsorption capacity of three distinct derived biochars [biosolids (BDΒ), cattle manure (MDB) and spent coffee grounds (SCGDB)], applied either at a low (1 g L−1) or high (10 g L−1) dose on seven antibiotics (tetracycline, TET; erythromycin, ERY; clarithromycin, CLA; ampicillin, AMP; ofloxacin, OFL; sulfamethoxazole, SMX; trimethoprim, TMP) spiked as mixture in environmentally relevant concentration (100 μg L−1) of an aqueous solution (8.27  85%) of AMP and TMP. However, the studied biochars failed to remove OFL and SMX. The adsorption results were best fitted to the Freundlich model with the sole exception of SMX. The main responsible mechanisms for the adsorption of antibiotics included surface complexation, H-bonding, π-π electron-donor-acceptor (EDA) interactions, pore-filling effects or the simultaneous occurrence of several of these mechanisms. Overall, the results highlighted the potential utilization of BDB, MDB and SCGDB for the decontamination of antibiotics-contaminated water bodies, while promoting the circular economy strategy.