School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin 150030, China; Joint Laboratory of Northeast Agricultural University and Max Planck Institute of Colloids and Interfaces (NEAU-MPICI), Harbin 150030, China.
Joint Laboratory of Northeast Agricultural University and Max Planck Institute of Colloids and Interfaces (NEAU-MPICI), Harbin 150030, China.
J Hazard Mater. 2020 May 5;389:122115. doi: 10.1016/j.jhazmat.2020.122115. Epub 2020 Jan 16.
In this paper, we have successfully prepared porous magnetic biochar with excellent surface area and recovery rate using corn stalks (CS) and waste iron (WI) as precursors. Notably, in order to prevent the incorporated iron oxides from blocking the carbon pores, then resulting in a decrease in specific surface area and reducing the removal efficiency of the material, the optimum range of iron ions can be determined to be 0.04-0.06 mol/L according to the effect of the amount of iron on the magnetic biochar recovery rate and Pb removal capacity. Furthermore, as-synthesized artificial humic acid (A-HA) obtained from waste biomass by hydrothermal humification (HTH) technology has abundant functional groups, which can complex with heavy metals and metal oxides. Therefore, A-HA is introduced as an activator to produce novel porous magnetic biochar materials (AHA/FeO-γFeO@PBC) with abundant functional groups (i.e., phenolic-OH, -COOH, etc.), providing high dispersibility and stability, further leading to excellent removal performance (Langmuir removal capacity up to 99.82 mg/g) and recyclable performance (removal capacity after 5 removal cycles is 79.04 mg/g). Multiple removal mechanisms have been revealed, including reduction, complexation, and precipitation.
在本文中，我们成功地使用玉米秸秆 (CS) 和废铁 (WI) 作为前体制备了具有优异比表面积和回收率的多孔磁性生物炭。值得注意的是，为了防止掺入的氧化铁堵塞碳孔，从而导致比表面积降低和材料去除效率降低，可以根据铁的量对磁性生物炭回收率和 Pb 去除能力的影响，确定铁离子的最佳范围为 0.04-0.06 mol/L。此外，通过水热腐殖化 (HTH) 技术从废生物质中合成的人工腐殖酸 (A-HA) 具有丰富的官能团，可以与重金属和金属氧化物络合。因此，引入 A-HA 作为活性剂来制备具有丰富官能团（如酚-OH、-COOH 等）的新型多孔磁性生物炭材料 (AHA/FeO-γFeO@PBC)，提供高分散性和稳定性，进一步导致优异的去除性能（朗缪尔去除容量高达 99.82 mg/g）和可回收性能（5 次去除循环后的去除容量为 79.04 mg/g）。揭示了多种去除机制，包括还原、络合和沉淀。
