纳米复合水凝胶的制备及其对重金属离子的吸附 |
摘要点击 2782 全文点击 1567 投稿时间:2015-12-30 修订日期:2016-03-14 |
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中文关键词 水合氧化锰 纳米复合水凝胶 重金属离子 吸附机制 |
英文关键词 hydrous manganese dioxide nanocomposite hydrogel heavy metal ions adsorption mechanism |
作者 | 单位 | E-mail | 朱倩 | 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023 | zhuqian9018@163.com | 李正魁 | 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023 | zhkuili@nju.edu.cn | 张一品 | 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023 | | 韩华杨 | 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023 | | 王浩 | 南京大学环境学院, 污染控制与资源化研究国家重点实验室, 南京 210023 | |
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中文摘要 |
以N-羟甲基丙烯酰胺(HMAm)和2-丙烯酸羟乙酯(HEA)为共聚单体,采用60 Co-γ射线低温辐照法,制备了具酰胺基和羟基的新型聚合物水凝胶p(HMAm/HEA),运用原位沉淀法制备了纳米复合水凝胶HMO-p(HMAm/HEA),用于对重金属离子Pb2+和Cu2+的去除. 应用 SEM、TEM、FTIR等方法对水凝胶进行表征,表征结果证明p(HMAm/HEA)是HMAm和HEA的共聚产物,且纳米水合氧化锰(HMO)成功负载. 探讨了溶液初始pH值、反应温度、重金属初始浓度、反应时间、竞争性Ca2+和Na+浓度等因素对纳米复合水凝胶吸附过程的影响,研究表明HMO-p(HMAm/HEA)对Pb2+和Cu2+的吸附过程不受温度的影响;吸附量随着溶液初始pH 的升高而增加;吸附过程属于Langmuir单分子层吸附;吸附动力学过程符合准二级动力学吸附;高浓度的Ca2+和Na+对吸附过程影响不大. XPS图谱进一步证明吸附机制是重金属离子与羟基间的离子交换作用. 采用0.05 mol·L-1的HCl溶液为脱附剂,经过4次吸附-脱附循环再生后,纳米复合水凝胶重复利用性好. |
英文摘要 |
An acylamino and hydroxyl functionalized hydrogel [p(HMAm/HEA)] was newly prepared by the 60 Co-γ-induced polymerization of N-hydroxymethyl acrylamide (HMAm) and 2-hydroxyethyl acrylate (HEA). Then the copolymer p(HMAm/HEA) hydrogel was utilized for in situ nanosized hydrous manganese dioxide (HMO) loading to prepare nanocomposite hydrogel HMO-p(HMAm/HEA) for Pb2+ and Cu2+ removal. The nanocomposite hydrogel was characterized by SEM, TEM and FTIR, showing that p(HMAm/HEA) hydrogel was indeed a copolymer of HMAm and HEA monomers, and the loading of HMO nanoparticles onto p(HMAm/HEA) was successful. Various influencing parameters on heavy metal ions removal by HMO-p(HMAm/HEA), such as initial pH, temperature, initial heavy metal concentration, contact time and competing Ca2+ and Na+, were estimated. The results showed that the adsorption process was temperature-independent, pH-sensitive, Langmuir monolayer adsorption and followed a pseudo-second-order rate equation. The presence of high concentrations of competing Ca2+ and Na+ had no significant effect on the adsorption process. The XPS spectra analyses further indicated that Pb2+ and Cu2+ were adsorbed via the ion exchange of —OH groups. Moreover, HMO-p(HMAm/HEA) could be regenerated by 0.05 mol·L-1 of HCl, and obtained excellent repeated use. |
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