In this study, a novel magnetic composite of polyacrylamide-modified Fe₃O₄/MnO₂ (PFM) was successfully synthesized and introduced to remove cadmium and copper ions from water. The characterization methods of vibrating sample magnetometry, X-ray diffraction, scanning electron microscopy with energy dispersive spectrometer, Fourier transform infrared spectroscopy, and Brunauer-Emmett-Teller were applied to examine the ferromagnetism, to compare the crystal structure, to examine the crystal shape change and elemental composition change, to examine the composition change, and to compare the specific surface area, respectively. The effects of various factors, including adsorbent dosage, initial ion concentration, and adsorption time, were evaluated. Under the condition of 50 mg/L Cu²⁺ or Cd²⁺ concentration, 1.6 g/L nano-PFM, and pH 6, the adsorption equilibrium was considered to have been reached when the solution has been adsorbed for an adsorption time of 400 min. Using the condition of 50 mg/L Cu²⁺ or Cd²⁺ solution as an example, the removal efficiency of Cu²⁺ and Cd²⁺ reached 96.91% and 78.10% and the adsorption capacity of them reached 30.285 mg/g and 39.052 mg/g, respectively. Additionally, a competing ions adsorption experiment was carried out to determine which ion’s adsorption capacity is larger in aqueous solution of both Cd²⁺ and Cu²⁺ ions. The result indicated that Cu²⁺ binds more easily with the active sites on the surface of the nano-PFM. An experiment of five consecutive adsorption–regeneration cycles confirmed that the adsorbent can be reused successfully for Cd²⁺ and Cu²⁺ adsorption and that it has promising potential for practical application.

在这项研究中，一种新型的聚丙烯酰胺改性的Fe ₃ O ₄ / MnO ₂磁性复合材料（PFM）已成功合成，并被引入以去除水中的镉和铜离子。利用振动样品的磁力分析，X射线衍射，能量色散谱仪的扫描电子显微镜，傅里叶变换红外光谱和Brunauer-Emmett-Teller的表征方法来检查铁磁性，比较晶体结构，检查晶体形状变化和元素组成变化，分别检查组成变化和比较比表面积。评估了各种因素的影响，包括吸附剂量，初始离子浓度和吸附时间。在50 mg / L Cu ²⁺或Cd ^{2+的条件下}浓度，1.6 g / L纳米PFM和pH值为6时，认为当溶液吸附时间为400分钟时，已达到吸附平衡。以50 mg / L的Cu ²⁺或Cd ²⁺溶液为例，Cu ²⁺和Cd ²⁺的去除率分别达到96.91％和78.10％，吸附容量分别为30.285 mg / g和39.052。分别为mg / g。另外，进行竞争性离子吸附实验以确定在Cd ²⁺和Cu ²⁺离子的水溶液中哪个离子的吸附能力更大。结果表明Cu ²⁺与纳米PFM表面上的活性位点更容易结合。连续五个吸附-再生循环的实验证实，该吸附剂可以成功地重新用于Cd ²⁺和Cu ²⁺吸附，并且具有实际应用前景。