Environmental pollution by toxic metals causes serious health complications, thus requiring advanced remediation methods for waters and effluents. In particular, chitosan-based magnetic materials have been recently developed to remove metals from aqueous solutions, industrial wastewater and water from lakes and rivers. Here, we review the adsorption of lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As) using magnetic chitosan. The manuscript presents recent experimental findings on the synthesis of magnetic adsorbents, focusing on magnetization methods, the main aspects of adsorption and adsorbent regeneration. The major findings are: (1) Kinetic patterns are mostly correlated by pseudo-second-order equations. (2) Langmuir isotherm model provides satisfactory estimations of monolayer capacity, the highest reported values being 341.7 mg/g for lead, 152 mg/g for mercury, 321.9 mg/g for cadmium and 65.5 mg/g for arsenic. (3) Most magnetic chitosan-based adsorbents keep their magnetic features and adsorption efficiency in consecutive adsorption–desorption runs. Overall, most chitosan-based magnetic adsorbents provide effective uptake of toxic metals ions from aqueous media and have a high degree of reusability.

有毒金属对环境的污染会导致严重的健康并发症，因此需要对水和废水进行高级修复的方法。特别地，近来已经开发了基于壳聚糖的磁性材料，以去除水溶液，工业废水和湖泊和河流中的水中的金属。在这里，我们回顾了使用磁性壳聚糖对铅（Pb），镉（Cd），汞（Hg）和砷（As）的吸附。该手稿介绍了磁性吸附剂合成的最新实验结果，重点是磁化方法，吸附和吸附剂再生的主要方面。主要发现是：（1）动力学模式主要与拟二阶方程相关。（2）Langmuir等温线模型提供了令人满意的单层容量估算，报告的最高值为341。铅为7 mg / g，汞为152 mg / g，镉为321.9 mg / g，砷为65.5 mg / g。（3）大多数基于壳聚糖的磁性吸附剂在连续的吸附-解吸过程中均保持其磁性和吸附效率。总体而言，大多数基于壳聚糖的磁性吸附剂可有效吸收水性介质中的有毒金属离子，并具有高度的可重复使用性。