Department of Biological and Agricultural Engineering & Texas A&M AgriLife Research Center, Texas A&M University, TX, 77843, USA.
Department of Biological and Agricultural Engineering & Texas A&M AgriLife Research Center, Texas A&M University, TX, 77843, USA; Department of Wildlife, Sustainability, and Ecosystem Sciences, Tarleton State University, TX, 76401, USA.
Chemosphere. 2021 Jun;273:129649. doi: 10.1016/j.chemosphere.2021.129649. Epub 2021 Jan 13.
Novel iron activated biochars (FA-BCs) were prepared via simultaneous pyrolysis and activation of FeCl-pretreated bermudagrass (BG) for removing microcystin-LR (MC-LR) in aqueous solution. Compared to the raw BC (without activation), the surface area and adsorption capacity of FA-BC at iron impregnation ratio of 2 (2 g FeCl/g BG) were enhanced from 86 m/g and 0.76 mg/g to 835 m/g and 9.00 mg/g. Moreover, FA-BC possessed various iron oxides at its surface which provided the catalytic capacity for regeneration of MC-LR spent FA-BC and magnetic separation after the MC-LR adsorption. Possible mechanisms for the MC-LR adsorption onto FA-BC would include electrostatic attraction, π-π, hydrogen bond, and hydrophobic interactions. The detailed adsorption studies indicated mainly chemisorption and intra-particle diffusion limitation would participate in the adsorption process. The thermal regeneration at 300 °C kept high regeneration efficiency (99-100%) for the MC-LR spent FA-BC during four cycles of adsorption-regeneration. In addition, the high regeneration efficiency (close to 100%) was also achieved by persulfate oxidation-driven regeneration. FA-BC also exhibited high adsorption capacity for the MC-LR from the real lake water to meet the MC-LR concentration below 1 μg/L as a safe guideline suggested by WHO.
新型铁激活生物炭（FA-BC）通过 FeCl3 预处理的百喜草（BG）的同时热解和活化制备，用于去除水溶液中的微囊藻毒素-LR（MC-LR）。与原始 BC（未经活化）相比，在铁浸渍比为 2（2 g FeCl3/g BG）时，FA-BC 的表面积和吸附容量从 86 m2/g 和 0.76 mg/g 增强到 835 m2/g 和 9.00 mg/g。此外，FA-BC 表面具有各种氧化铁，为 MC-LR 耗尽的 FA-BC 的再生和 MC-LR 吸附后的磁性分离提供了催化能力。FA-BC 吸附 MC-LR 的可能机制包括静电吸引、π-π、氢键和疏水相互作用。详细的吸附研究表明，主要的化学吸附和颗粒内扩散限制会参与吸附过程。在 300°C 的热再生过程中，在四个吸附-再生循环中，MC-LR 耗尽的 FA-BC 保持了 99-100%的高再生效率。此外，过硫酸盐氧化驱动的再生也实现了高的再生效率（接近 100%）。FA-BC 还表现出从实际湖水对 MC-LR 的高吸附容量，以满足世界卫生组织建议的 1μg/L 以下的 MC-LR 浓度作为安全指导方针。
