Magnetic Fe₃O₄[email protected] (Fe₃O₄[email protected]) composites using natural materials were synthesized and used to remediate acid mine drainage (AMD) for heavy metal removal. It was found that the composites had a good magnetism, high stability and good performance in removal of Cr(VI) in the synthetic aqueous solutions. The thermodynamic parameters showed that Cr(VI) adsorption onto Fe₃O₄[email protected] was an exothermic and spontaneous process. The adsorption kinetics was well described by a pseudo-second-order model, and the adsorption isotherms fit the Langmuir model with a maximum adsorption capacity of 62.1 mg/g at 25 °C. Solution pH was a key factor for adsorption and the optimized pH was 2.0. Fe₃O₄[email protected] could be easily recycled through an external magnetic field and the adsorption capacity reduced by only 3% after five consecutive adsorption–desorption processes. In addition, Fe₃O₄[email protected] was found to be an excellent adsorbent for actual AMD remediation containing Cd, Cr, Cu, Fe Zn, Ni and Pb, suggesting that the Fe₃O₄[email protected] was an effective and economical adsorbent for the treatment of AMD.

合成了使用天然材料的磁性Fe ₃ O ₄ [受电子邮件保护]（Fe ₃ O ₄ [受电子邮件保护]）复合材料，并用于补救酸性矿山排水（AMD）以去除重金属。发现该复合材料具有良好的磁性，高稳定性以及在合成水溶液中去除Cr（VI）的良好性能。热力学参数表明Cr（VI）吸附在Fe ₃ O _4上[电子邮件保护]是一个放热的自发过程。吸附动力学由拟二阶模型很好地描述，吸附等温线符合Langmuir模型，在25°C下的最大吸附容量为62.1 mg / g。溶液的pH值是吸附的关键因素，最优化的pH值为2.0。Fe ₃ O ₄ [受电子邮件保护]可以很容易地通过外部磁场进行再循环，并且经过五个连续的吸附-解吸过程后，吸附量仅降低了3％。此外，发现Fe ₃ O ₄ [受电子邮件保护]是一种实际的AMD修复剂，其中包含Cd，Cr，Cu，Fe Zn，Ni和Pb，是极好的吸附剂，表明Fe ₃ O ₄[电子邮件保护]是一种有效且经济的AMD吸附剂。