Wang Fuchun, Wang Wankun, Su Xiang
School of Materials and Energy Engineering, Guizhou Institute of Technology, Guiyang 550005, China.
Key Laboratory of Light Metal Materials Processing Technology of Guizhou Provinces, Guiyang 550003, China.
Langmuir. 2024 Apr 16;40(15):8035-8045. doi: 10.1021/acs.langmuir.3c03989. Epub 2024 Apr 3.
The recovery of precious metals, such as palladium (Pd), from wastewater, is an economically important field. The present study reports the application of polyglycidyl methacrylate (PGMA) macroporous spheres with diethylaminoethyl (DEAE) functional groups (PGMA-DEAE) for the adsorption of palladium ions [Pd(II)] from simulated wastewater solutions. The effects of pH, adsorption duration, and initial concentration of Pd(II) on the adsorption amount were evaluated systematically. The results revealed that within the experimental pH range, the adsorption efficiency of Pd(II) increased with increasing pH. In particular, between pH 4 and 6, the Pd(II) adsorption efficiencies were approximately 100%. At 298 K and pH ∼ 4, the adsorption capacity of PGMA-DEAE for Pd(II) was 1.22 mmol/g. The adsorption rates of PGMA-DEAE for Pd(II) were high, and the adsorption equilibrium was reached within 10 min. Ca(II), Mg(II), Co(II), Cu(II), Ni(II), and Fe(II) were selected as representative competitive adsorption metal ions. PGMA-DEAE had good separation selectivity for Pd(II) at pH 1-6 (all > 30), especially at pH ∼ 4 (all > 100). The SEM, TEM, EDS, TG, XRD, and XPS results indicated that in a high-acidity environment ( ≥ 1 mol/L), Pd(II) was adsorbed on PGMA-DEAE through electrostatic attraction, while in a low-acidity environment (pH 1-6), Pd(II) was adsorbed on PGMA-DEAE through coordinated bonding between the Pd(II) ions and the N. PGMA-DEAE exhibited excellent stability and regeneration performance for five regeneration cycles.
从废水中回收钯（Pd）等贵金属是一个具有重要经济意义的领域。本研究报道了具有二乙氨基乙基（DEAE）官能团的聚甲基丙烯酸缩水甘油酯（PGMA）大孔球（PGMA-DEAE）用于从模拟废水溶液中吸附钯离子[Pd(II)]。系统评估了pH值、吸附时间和Pd(II)初始浓度对吸附量的影响。结果表明，在实验pH范围内，Pd(II)的吸附效率随pH值升高而增加。特别是在pH 4至6之间，Pd(II)的吸附效率约为100%。在298 K和pH约为4时，PGMA-DEAE对Pd(II)的吸附容量为1.22 mmol/g。PGMA-DEAE对Pd(II)的吸附速率很高，在10分钟内达到吸附平衡。选择Ca(II)、Mg(II)、Co(II)、Cu(II)、Ni(II)和Fe(II)作为代表性的竞争性吸附金属离子。PGMA-DEAE在pH 1至6时对Pd(II)具有良好的分离选择性（均>30），尤其是在pH约为4时（均>100）。扫描电子显微镜（SEM）、透射电子显微镜（TEM）、能谱仪（EDS）、热重分析仪（TG）、X射线衍射仪（XRD）和X射线光电子能谱仪（XPS）结果表明，在高酸性环境（≥1 mol/L）中，Pd(II)通过静电引力吸附在PGMA-DEAE上，而在低酸性环境（pH 1至6）中，Pd(II)通过Pd(II)离子与N之间的配位键吸附在PGMA-DEAE上。PGMA-DEAE在五个再生循环中表现出优异 的稳定性和再生性能。
