Removal of sulfonamide antibiotics by constructed wetland substrate with NaOH-modified corn straw biochar under different operating conditions

Abstract

This study examined the elimination of sulfonamide antibiotics (SAs) by constructed wetland substrates with NaOH-modified corn straw biochar and assessed the impact of environmental conditions on the effectiveness of SAs removal. The study demonstrated that the constructed wetland substrate with NaOH-modified biochar significantly eliminated eight SAs, with a removal rate of over 94 %. During the removal process, the intermediates will undergo regeneration of the parent compounds under low DO concentrations. This was based on the linear stepwise regression analysis and Geodetector models. The results showed that SA types COD, NH₄⁺-N, TN, and DO had a stronger influence. The dominant bacteria in the constructed wetland system were mainly affected by antibiotic concentration, DO, NH₄⁺-N and NO₃^–-N, which affected the removal of antibiotics. Overall, the constructed wetland substrate with NaOH-modified corn straw biochar can be effectively employed as an ecological method for eliminating SAs from the environment.