Integration of bimetallic organic frameworks and magnetic biochar for azole fungicides removal

Abstract

It is urgent to develop an excellent adsorbent with higher adsorption capacity and cost-effective to efficiently purify azole fungicides contained water, and reduce the potential negative impacts on environment. In this work, a novel magnetic composite (MBC@Fe/Mg-MIL-88B)11MBC: Magnetic biochar, BC: Biochar, MIL: Materials of Institute Lavoisier was synthesized by integrating magnetic wheat straw biochar (MBC) and bimetallic organic framework (Fe/Mg-MIL-88B) as well as employed as a high-efficiency adsorbent for azole fungicides removal. Subsequently, the morphology and structure of as-synthesized composites were discerned by a series of characterizations. The adsorption performance of MBC@Fe/Mg-MIL-88B composites was systematically investigated and the maximum adsorption capacity towards epoxiconazole and flusilazole were 86.11 mg g−1 and 89.87 mg g−1, respectively. The adsorption process was suitable for the pseudo-second-order kinetic model and Langmuir isotherm model. The MBC@Fe/Mg-MIL-88B could adapt to a relatively wide range of pH (2-11). The thermodynamics illustrated that adsorption process was spontaneous, endothermic and feasible. The adsorption of azole fungicides onto MBC@Fe/Mg-MIL-88B was a single-layer chemical adsorption process and based on the mechanisms of electrostatic interaction, hydrogen bonding, covalent bonding and π-π stacking. This study offers a promising method for the removal of azole fungicides from environmental water samples.