Enhanced removal of endocrine disrupting chemicals by chemically modified biochar: Efficiency and mechanisms

Abstract

Endocrine disrupting chemicals (EDCs) are pollutants found in low concentrations but with high toxicity. Therefore, selecting suitable methods to manage and mitigate the risks associated with EDCs is of utmost practical importance. This study delves into the removal mechanism of EDCs using chemically modified biochar, summarizing the sources, classifications, removal technologies of EDCs, and biochar modification methods. Furthermore, it examines the synergistic mechanism of chemically modified biochar in mediating EDCs removal. The results of 32 chemical modification experiments summarized indicate that chemical modification alters the specific surface area, pore size, and O/C ratio of biochar. Notably, 78.1 % of the studies found that chemically modified biochar enhanced the specific surface area. In the actual removal process of pollutants by biochar, multiple interactions are involved, including π-π bond interactions, hydrogen bond interactions, electrostatic interactions, hydrophobic interactions, and pore filling. These mechanisms typically function in combination rather than in isolation. The 20 studies reviewed demonstrated that the removal rate of EDCs by chemically modified biochar ranged from 63.3 % to 100 %. Furthermore, this article suggests future research for the removal of EDCs using chemically modified biochar, to offer environmentally friendly solutions for EDCs removal in water and serve as a reference for efficient removal.