Tang Jingchun, Zhao Beibei, Lyu Honghong, Li Ding
Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Tianjin Key Laboratory of Clean Energy and pollution control, School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin 300401, China.
J Hazard Mater. 2021 Jul 5;413:125415. doi: 10.1016/j.jhazmat.2021.125415. Epub 2021 Feb 13.
As a natural reduction mineral, pyrite (FeS), was combined with biochar by simply ball milling technology to synthesize FeS@biochar composite (BM-FeS@BC) and applied for the removal of hexavalent chromium (Cr(VI)) in aqueous solution. SEM, XRD, FTIR, and XPS characterization results showed that the FeS and biochar were successfully combined and biochar suppressed the agglomeration of FeS. Batch sorption experiments showed that the BM-FeS@BC700 composite (mass ratio of FeS-to-biochar = 3:1) had enhanced Cr(VI) removal capacity of 134 mg·g, which were 3-25 times higher than those of the corresponding pristine and ball-milled biochar and FeS. The removal of Cr(VI) by BM-FeS@BC700 was dosage and pH dependent. The addition of oxalic acid (OA) exhibited a promotion effect on the removal of Cr(VI) by increasing the removal rate of Cr(VI) from 56% to 100%. Reduction, adsorption, and surface complexation were the dominate mechanisms for Cr(VI) removal by BM-FeS@BC700. At the equilibrium Cr(VI) concentration of 15.7 mg·L, 92.25% of Cr(VI) was removed through reduction/precipitation and 8.75% was removed by adsorption/surface complexation. The fitting results of the Langmuir model proved that the removal of Cr(VI) by BM-FeS@BC700 composite was chemical surface monolayer adsorption. This work demonstrates the potential of ball milling for the preparation of FeS@BC composite to remove Cr(VI) from water and wastewater.
作为一种天然还原矿物，黄铁矿（FeS）通过简单的球磨技术与生物炭结合，合成了FeS@生物炭复合材料（BM-FeS@BC），并将其应用于去除水溶液中的六价铬（Cr(VI)）。扫描电子显微镜（SEM）、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）表征结果表明，FeS与生物炭成功结合，且生物炭抑制了FeS的团聚。批量吸附实验表明，BM-FeS@BC700复合材料（FeS与生物炭的质量比为3:1）对Cr(VI)的去除能力增强，达到134 mg·g，比相应的原始生物炭、球磨生物炭和FeS高3至25倍。BM-FeS@BC700对Cr(VI)的去除量和pH值有关。添加草酸（OA）对Cr(VI)的去除具有促进作用，使Cr(VI)的去除率从56%提高到100%。还原、吸附和表面络合是BM-FeS@BC700去除Cr(VI)的主要机制。在Cr(VI)平衡浓度为15.7 mg·L时，92.25%的Cr(VI)通过还原/沉淀去除，8.75%通过吸附/表面络合去除。Langmuir模型的拟合结果证明，BM-FeS@BC700复合材料对Cr(VI)的去除是化学表面单层吸附。这项工作证明了球磨法制备FeS@BC复合材料用于去除水和废水中Cr(VI)的潜力。
