| 摘要: |
| 为改善钠基膨润土对Pb（Ⅱ）的吸附效果，以羟基镧和壳聚糖作为柱化剂，采用水热法对钠基膨润土进行柱撑改性，制得壳聚糖/羟基镧复合柱撑膨润土（GZ-P）。利用XRD、FTIR、SEM等手段对GZ-P进行表征分析，研究了GZ-P对Pb（Ⅱ）的吸附行为。研究结果表明：壳聚糖和羟基镧离子插入到膨润土层间，起到了"柱撑"的作用，颗粒变得更加饱满密实，表面空隙和粗糙程度有所增加；在25℃，吸附时间为120 min时，GZ-P对Pb（Ⅱ）的去除率和吸附量随pH值的增加呈现先增后减再增的态势，在pH=4时去除率最高，达到98.93%，最大吸附量为33.67 mg·g-1，在pH=6时的吸附量最少，但去除率也超过85%；GZ-P对Pb（Ⅱ）的吸附等温线与Langmuir方程拟合较好，为近单分子层吸附；吸附动力学过程可用准二级动力学模型描述，主要受化学吸附的控制。 |
| 关键词: 壳聚糖/羟基镧复合柱撑膨润土(GZ-P) 吸附 Pb(Ⅱ) 吸附等温线 动力学 |
| DOI：10.11835/j.issn.1000-582X.2018.05.010 |
| 分类号:X703.5 |
| 基金项目:重庆市教育委员会资助项目（KJKJ1730418，KJKJ1730413）。 |
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| Adsorption property on Pb(Ⅱ) of bentonite modified by chitosan/hydroxy-lanthanum |
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BIAN Lingtao1, ZHANG Lianke2, LI Haipeng2, GAO Yanhong3
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1.School of Architecture and Material, Chongqing College of Electronic Engineering, Chongqing 401331, P. R. China;2.School of Environment and Energy, Inner Mongolia University of Science and Technology, Baotou 014010, P. R. China;3.School of Metallurgy and Materials Engineering, Chongqing University of Science and Technology, Chongqing 401331, P. R. China
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| Abstract: |
| To improve adsorption effect of Na-bentonite on Pb(Ⅱ), chitosan/hydroxy-lanthanum complex pillared bentonite (GZ-P) is prepared by hydrothermal synthesis method using Na-Bentonite modified with the mixture of chitosan and hydroxy-lanthanum cation as pillared agent. The properties of GZ-P are characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), scanning electron microscopy (SEM) and other analytical methods. And the adsorption property of Pb(Ⅱ) by GZ-P is discussed. The results show that the mixture of chitosan and hyroxy-lanthanum cation intercalates into bentonite and plays the role of pillar. The particles become fuller and denser. Surface voids and roughness increases. Removal rate and adsorption capacity of Pb(Ⅱ) by GZ-P increase first and then decrease, and increase again with the increase of PH value when the temperature is 25℃ and reaction time is 120 min. The highest removal rate reached to 98.93% and the maximum Pb2+ adsorption capacity is 33.67 mg/g when initial pH is 4. The least adsorption capacity is found when pH is 6. However, the removal rate is more than 85% even under that condition. Langmuir equation could better imitate the adsorption isothermal process of GZ-P to Pb(Ⅱ), and the adsorption process could be fitted by the pseudo-second order model, which indicates that Pb(Ⅱ) ions are adsorbed onto GZ-P by chemical interactions via monolayer. |
| Key words: chitosan/hydroxy-lanthanum complex modified bentonite (GZ-P) adsorption pb(Ⅱ) adsorption isotherms kinetics |
