Regenerable hydrogels based on poly(acrylic acid-sodium acrylate-acrylamide) modified by sodium humate for high removal of Pb2+ and Fe2+ ions: metal adsorption kinetics and thermodynamic studies
Regenerable hydrogels based on poly(acrylic acid-sodium acrylate-acrylamide) modified by sodium humate for high removal of Pb2+ and Fe2+ ions: metal adsorption kinetics and thermodynamic studies
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DOI：
10.1080/19443994.2013.808588
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发表时间：
2014-08
影响因子：
1.1
通讯作者：
T. Singh;R. Singhal
中科院分区：
文献类型：
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作者：
T. Singh;R. Singhal
摘要以聚（丙烯酸-丙烯酸钠-丙烯酰胺）/腐植酸钠/聚（AAc-SA-AM）/SH为基的新型高吸水性水凝胶为吸附剂，对水溶液中的金属离子（Pb 2+、Fe 2+）进行吸附。研究了影响聚（AAc-SA-AM）/SH水凝胶吸附容量的因素，如接触时间、pH、温度、SH含量（wt.%），系统地研究了金属离子的初始浓度和离子强度。实验结果表明，适量的SH（2.44wt.%）不仅提高了聚（AAc-SA-AM）水凝胶对金属离子的吸附能力，而且提高了其再生能力。结果表明，吸附平衡数据较好地符合Langmuir吸附等温式，而Freundlich吸附等温式较好。对于每g聚（AAc-SA-AM）/SH（SH 4）水凝胶，Pb 2+离子的最大结合容量为198 mg/g/l，Fe 2+离子的最大结合容量为164 mg/g/l（与许多其它吸附剂相比高）。计算了热力学参数的变化，并对负温度系数进行了分析。
ABSTRACTA novel superabsorbent hydrogel based on poly(acrylic acid-sodium acrylate-acrylamide)/sodium humate poly(AAc-SA-AM)/SH was applied as adsorbent to adsorb metal ions (Pb2+, Fe2+) from the aqueous solutions. The factors affecting adsorption capacity of the poly(AAc-SA-AM)/SH hydrogel such as contact time, pH, temperature, SH content (wt.%), initial concentration of the metal ion, and ionic strength were systematically investigated. Results from the experimental data revealed that an appropriate addition of SH (2.44 wt.%) not only increases the metal ion adsorption of poly(AAc-SA-AM) hydrogel but also improves its regeneration ability. The results showed that the adsorption equilibrium data fitted the Langmuir isotherm better than the Freundlich isotherm. The maximum binding capacity for Pb2+ ion was 198 and 164 mg/g/l for Fe2+ ion for per g of poly(AAc-SA-AM)/SH (SH4) hydrogel (high as compared to many other adsorbents). The changes in thermodynamic parameters were also calculated, and the negative...