Abstract

A novel composite adsorbent was prepared by polydopamine (PDA) coating, amination, and carboxylation modification using basalt fiber (BF) as the carrier material for the removal of Cu²⁺ from water. The resulting adsorbent, BF/PDA-iminodiacetic acid (IDA), was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis. The effects of pH, ionic strength, temperature, and duration on the adsorption properties of BF/PDA-IDA were investigated by batch experiments. The maximum uptake capacity for Cu²⁺ was 22.96 mg/g at 303 K. The adsorption process conformed to pseudo-second-order kinetics and the equilibrium can be reached within two hours. The Langmuir isotherm equation fitted well to the adsorption isotherm experimental data. Thermodynamic analysis showed that the adsorption process was spontaneous and exothermal. Furthermore, BF/PDA-IDA can be easily recovered by 0.1 mol/L Na₂EDTA and about 90% adsorption capacity remained after four successive regeneration cycles. The adsorption mechanism could be a combination of chelation and electrostatic interactions. This study demonstrated that the adsorbent prepared from BF skeleton has great potential to remove Cu²⁺ from water.

摘要

以玄武岩纤维(BF)为载体材料，通过聚多巴胺(PDA)包覆、胺化和羧化改性制备了一种新型复合吸附剂，用于去除水中的Cu 2+ ^。通过扫描电子显微镜、傅里叶变换红外光谱、X 射线光电子能谱和热重分析对所得吸附剂 BF/PDA-亚氨基二乙酸 (IDA) 进行了表征。通过批量实验研究了 pH、离子强度、温度和持续时间对 BF/PDA-IDA 吸附性能的影响。^{Cu 2+}的最大吸收容量在303 K时为22.96 mg/g。吸附过程符合准二级动力学，可在2小时内达到平衡。Langmuir 等温线方程与吸附等温线实验数据非常吻合。热力学分析表明吸附过程是自发的和放热的。此外，BF/PDA-IDA可以很容易地被0.1 mol/L Na ₂ EDTA回收，并且在四个连续的再生循环后仍保持约90%的吸附容量。吸附机制可能是螯合和静电相互作用的结合。该研究表明，由 BF 骨架制备的吸附剂具有从水中去除 Cu ²⁺的巨大潜力。