Adsorption of sulfamethoxazole by wheat straw-derived biochars in seawater

Abstract

The excessive use of antibiotics in mariculture have resulted in high pollution burdens of antibiotics in marine environment. Biochars, as promising adsorbents, have been widely used in organic pollutant adsorption because of their good adsorption performance and stability. However, adsorption characteristic of antibiotics in seawater by biochar is not well known. Thus, the batch experiment for the adsorption of sulfamethoxazole (SMX) was conducted using wheat straw-derived biochars and graphite (GR) under different initial concentration of SMX and different addition of adsorbent in seawater. The results showed that the wheat straw-derived biochars produced at 700 °C was the optimal adsorbent with the maximum removal rate (R) of 70.3%, the maximum adsorption capacity (Qe) of 1.03 mg g-1 and the maximum adsorption coefficient (Kd) of 0.182 L g-1. The Qe values increased with increasing the initial concentration of SMX, while R and Kd values of SMX decreased. The R values of SMX increased with the increasing dosage of adsorbents, while Qe and Kd values of SMX decreased. These findings will shed new light on the environmentally-friendly and low-cost adsorbent for controlling the antibiotic pollution in marine environment.