Comparison of sulfamethoxazole adsorption by activated carbon and biochar in seawater

Abstract

Antibiotics, a type of emerging contaminants in marine environment, have posed serious threats to human health and ecological function. Biochar has been widely used in the remediation of multiple pollutants due to low cost and good adsorption characteristics. However, the adsorption characteristics of biochar for antibiotics in seawater are still unclear. Therefore, a coconut shell activated carbon (AC) and a sludge biochar produced at 700 °C (SB700) were selected to carry out batch adsorption experiments of sulfamethoxazole (SMX) under different adsorbent dosage and different initial concentration of SMX. These results showed that the maximum removal rate (R) of AC and SB700 was 99.9% and 97.9%, the maximum adsorption capacity (Qe) was 13.7 mg g-1 and 1.6 mg g-1, and the maximum adsorption coefficient (Kd) was 2142 L g-1 and 5.1 L g-1, respectively. Compared with SB700, AC showed the excellent performance in SMX adsorption. This study provided theoretical support and experimental basis for the development of highly efficient antibiotic adsorbents in marine ecosystem.