Arsenic-contaminated water with low concentration is a worldwide problem because of its inevitable toxicity. Therefore, it is of practical significance to develop an economical and environment-friendly adsorbent for arsenic removal. In this work, an eco-friendly Fe–Al bimetallic oxide/biochar adsorbent composites was successfully synthesized from discarded rice husk. The factors of different pH, reaction time, initial concentration and interfering ions were studied to further explore adsorption effect by adsorbent in low concentration arsenic solution. The results indicated that the adsorbent had the excellent adsorption capacity at 60 °C and phosphate has the greatest interference to the adsorption process among the selected five interfering ions. The experimental data are fitted to the adsorption isotherm and kinetic model, and the results are more consistent with Ferundlich model and pseudo-first-order kinetic model. Furthermore, it only takes 10 s to recover the prepared materials with magnets, and the removal rate of arsenic can be as high as 75% in the first time while the removal rate reaches above 30% in the fifth time at very low concentrations of contaminants. This study revealed that the prepared Fe–Al bimetallic oxide/biochar can be used as a potential adsorbent for the removal of arsenic at low concentrations for its simple synthesis, environmental friendliness and magnetic recovery.

由于其不可避免的毒性，低浓度砷污染水是一个世界性问题。因此，开发一种经济、环保的除砷吸附剂具有重要的现实意义。在这项工作中，从废弃的稻壳中成功合成了一种环保的 Fe-Al 双金属氧化物/生物炭吸附剂复合材料。研究了不同pH值、反应时间、初始浓度和干扰离子等因素，进一步探讨了吸附剂在低浓度砷溶液中的吸附效果。结果表明，吸附剂在 60 °C 下具有优异的吸附能力，在选定的 5 个干扰离子中，磷酸盐对吸附过程的干扰最大。实验数据拟合吸附等温线和动力学模型，结果与Ferundlich模型和拟一级动力学模型更一致。此外，用磁铁回收制备的材料只需10秒，第一次对砷的去除率可高达75%，而在极低的污染物浓度下，第五次去除率可达30%以上。 . 该研究表明，制备的 Fe-Al 双金属氧化物/生物炭由于其合成简单、环境友好和磁回收，可用作去除低浓度砷的潜在吸附剂。在极低的污染物浓度下，第一次对砷的去除率可达75%，第五次去除率可达30%以上。该研究表明，制备的 Fe-Al 双金属氧化物/生物炭由于其合成简单、环境友好和磁回收，可用作去除低浓度砷的潜在吸附剂。在极低的污染物浓度下，第一次对砷的去除率可达75%，第五次去除率可达30%以上。该研究表明，制备的 Fe-Al 双金属氧化物/生物炭由于其合成简单、环境友好和磁回收，可用作去除低浓度砷的潜在吸附剂。