Abstract

A chemical-modified biochar material (MGBC) derived from Brassica straw was synthesized using magnetic-gelatin as a modification reagent and employed to remove Cr(VI) from aqueous solution. MGBC before and after reacted with Cr(VI) was characterized by FT-IR, XRD, SEM-EDS, XPS, and VSM (Vibrating Sample Magnetometer). Characterization results indicated that the underlying mechanisms of remove Cr(VI) by MGBC were primarily relied on the chelation of functional groups and reduction-coupled surface precipitation. Additionally, the effect of pH, initial Cr(VI) concentration, adsorption time, ionic strength, and coexisting ions on adsorption capacity of MGBC were evaluated and optimized by batch adsorption experiments. All findings illustrated that the maximum adsorption capacity of MGBC for Cr(VI) was 434.85 mg/g obtained at pH = 1 and the adsorption process was highly dependent on pH, and well consistent with Freundlich model and Pseudo-second-order (PSO) model. Furthermore, approximately 72% of equilibrium adsorption capacity for Cr(VI) was still possessed by MGBC under a considerable degree of ionic strength or a given concentration of coexisting ions, which demonstrated that MGBC equipped with strong selective adsorption ability and anti-jamming capability in practical wastewater. All results herein manifested that MGBC equipped with favorable practicability and reusability, which could serve as a low-cost and high-efficiency adsorbent to remove Cr(VI) from complex water environment.

摘要

使用磁性明胶作为改性试剂合成了一种源自芸苔属秸秆的化学改性生物炭材料 (MGBC)，并用于从水溶液中去除 Cr(VI)。通过FT-IR、XRD、SEM-EDS、XPS和VSM（振动样品磁强计）对MGBC与Cr（VI）反应前后进行表征。表征结果表明，MGBC 去除 Cr(VI) 的潜在机制主要依赖于官能团的螯合和还原耦合的表面沉淀。此外，通过批量吸附实验评估和优化了 pH、初始 Cr(VI) 浓度、吸附时间、离子强度和共存离子对 MGBC 吸附能力的影响。所有发现都表明 MGBC 对 Cr(VI) 的最大吸附容量为 434。在 pH = 1 时获得 85 mg/g，吸附过程高度依赖于 pH，与 Freundlich 模型和伪二阶 (PSO) 模型非常一致。此外，在相当程度的离子强度或给定的共存离子浓度下，MGBC 仍具有约 72% 的 Cr(VI) 平衡吸附能力，这表明 MGBC 具有很强的选择性吸附能力和抗干扰能力。实用废水。所有结果都表明MGBC具有良好的实用性和可重复使用性，可以作为一种低成本、高效的吸附剂来去除复杂水环境中的Cr(VI)。在相当程度的离子强度或给定的共存离子浓度下，MGBC对Cr(VI)仍有约72%的平衡吸附能力，这表明MGBC在实际废水中具有很强的选择性吸附能力和抗干扰能力. 所有结果都表明MGBC具有良好的实用性和可重复使用性，可以作为一种低成本、高效的吸附剂来去除复杂水环境中的Cr(VI)。在相当程度的离子强度或给定的共存离子浓度下，MGBC仍具有约72%的平衡吸附Cr(VI)能力，表明MGBC在实际废水中具有较强的选择性吸附能力和抗干扰能力. 所有结果都表明MGBC具有良好的实用性和可重复使用性，可以作为一种低成本、高效的吸附剂来去除复杂水环境中的Cr(VI)。