刘剑,陈莉妃,彭钢,易正戟.Cu(II)和Pb(II)在NaA分子筛膜@Fe0固定床上的去除动力学[J].环境科学学报,2020,40(9):3259-3268
Cu(II)和Pb(II)在NaA分子筛膜@Fe0固定床上的去除动力学
- Removal kinetics of Cu(II) and Pb(II) onto NaA molecular sieve membrane@Fe0 composite in a fixed bed column
- 基金项目：国家自然科学基金项目（No.41773133）；湖南省教育厅资助科研项目（No.17A028）；湖南省自然科学基金项目（No.2019JJ50013）；衡阳市科技计划项目（No.2019yj011171）
- 刘剑
- 衡阳师范学院, 化学与材料科学学院, 功能金属有机材料湖南省普通高等学校重点实验室, 功能金属有机化合物湖南省重点实验室, 衡阳 421008
- 陈莉妃
- 衡阳师范学院, 化学与材料科学学院, 功能金属有机材料湖南省普通高等学校重点实验室, 功能金属有机化合物湖南省重点实验室, 衡阳 421008
- 彭钢
- 衡阳师范学院, 化学与材料科学学院, 功能金属有机材料湖南省普通高等学校重点实验室, 功能金属有机化合物湖南省重点实验室, 衡阳 421008
- 易正戟
- 衡阳师范学院, 化学与材料科学学院, 功能金属有机材料湖南省普通高等学校重点实验室, 功能金属有机化合物湖南省重点实验室, 衡阳 421008
- 摘要：以不锈钢纤维烧结毡为载体，采用二次生长和液相还原法合成了一种新型的微纤复合NaA分子筛膜@Fe0复合材料，考察了其对Cu（Ⅱ）和Pb（Ⅱ）混合溶液的去除动力学.首先，采用二次生长法在不锈钢纤维烧结毡上合成NaA分子筛膜，然后以七水硫酸亚铁、硼氢化钠和微纤复合NaA分子筛膜为原料，利用液相还原法制备微纤复合NaA分子筛膜@Fe0复合材料，并采用扫描电镜和X射线光电子能谱进行分析表征.然后，考察了连续固定床反应器中pH值、入口浓度和床层高度对Cu（Ⅱ）和Pb（Ⅱ）去除效果的影响，并采用Bohart-Adams和Yoon-Nelson模型进行拟合分析.结果表明，纳米零价铁被均匀负载于分子筛膜表面，经过固定床动力学实验后，铜和铅附着在复合材料上；随着pH增加或入口浓度降低，Cu（Ⅱ）和Pb（Ⅱ）的透过时间均延长，随着床层高度从0.45 cm增加到0.65 cm，Cu（Ⅱ）和Pb（Ⅱ）透过时间略有增加，继续增加床层高度到0.90 cm，Cu（Ⅱ）和Pb（Ⅱ）透过时间显著延长，当床层高度为0.90 cm时，70 min时Cu（Ⅱ）透过浓度达到入口浓度的4.3%，200 min时Pb（Ⅱ）透过浓度仅为入口浓度的5.6%.Bohart-Adams模型适合描述透过曲线的初始部分（C/C0<0.5），Yoon-Nelson模型更适合拟合长床柱中Cu（Ⅱ）和Pb（Ⅱ）的连续去除.
- Abstract：A novel microfiber supported NaA molecular sieve membrane@Fe0 composite was prepared using stainless steel fiber sintered felt as carrier by the secondary growth and liquid-phase reduction technique. The kinetics of simultaneous Cu(Ⅱ) and Pb(Ⅱ) removal from aqueous solution by the composite were systematically investigated. Firstly, a NaA molecular sieve membrane was synthesized on the stainless steel fiber sintered felt by secondary growth method; then, microfiber supported NaA molecular sieve membrane@Fe0 composite was prepared by liquid-phase reduction method using ferrous sulfate heptahydrate, sodium borohydride and NaA molecular sieve membrane as raw materials. The composites were characterized by SEM and XPS. The effects of pH value, inlet concentration and bed height on the simultaneous removal of Cu(Ⅱ) and Pb(Ⅱ) were studied in a continuous fixed bed column filled with microfiber supported NaA molecular sieve membrane@Fe0 composite. The Bohart-Adams and Yoon-Nelson models were used to analyze the experimental data of fixed bed. The results show that nano zero valent iron is uniformly loaded on the surface of NaA molecular sieve membrane, and the successful attachment of copper and lead to the composite was confirmed after the fixed bed kinetics experiment. With the increase of pH or the decrease of inlet concentration, the breakthrough time of Cu(Ⅱ) and Pb(Ⅱ) increased. With the increase of bed height from 0.45 cm to 0.65 cm, the breakthrough time of Cu(Ⅱ) and Pb(Ⅱ) increased slightly but increased significantly with the further increase of bed height to 0.90 cm. When the bed height is 0.90 cm, the breakthrough concentration of Cu(Ⅱ) reaches 4.3% of the inlet concentration at 70 min, and that of Pb(Ⅱ) reaches only 5.6% of the inlet concentration at 200 min. The Bohart-Adams model is suitable for describing the initial part of the breakthrough curve (C/C0<0.5). The Yoon-Nelson model is preferable to fit the continuous removal of Cu(Ⅱ) and Pb(Ⅱ) in a longer bed column.
