| 酸碱复合改性海泡石亚结构特征及其对Cd(Ⅱ)吸附性能 |
| 摘要点击 1607 全文点击 707 投稿时间：2019-06-30 修订日期：2019-08-20 |
| 查看HTML全文
查看全文 查看/发表评论 下载PDF阅读器 |
| 中文关键词 海泡石 酸碱改性 镉 亚结构特征 吸附 |
| 英文关键词 sepiolite acidic and basic modification cadmium substructure adsorption |
| 作者 | 单位 | E-mail | | 谢厦 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津 300191
农业农村部环境保护科研监测所, 天津市农业环境与农产品安全重点实验室, 天津 300191 | 2695163629@qq.com | | 徐应明 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津 300191
农业农村部环境保护科研监测所, 天津市农业环境与农产品安全重点实验室, 天津 300191 | | | 闫翠侠 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津 300191
新疆农业大学草业与环境科学学院, 乌鲁木齐 830052 | | | 罗文文 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津 300191
农业农村部环境保护科研监测所, 天津市农业环境与农产品安全重点实验室, 天津 300191 | | | 孙约兵 | 农业农村部环境保护科研监测所, 农业农村部产地环境污染防控重点实验室, 天津 300191
农业农村部环境保护科研监测所, 天津市农业环境与农产品安全重点实验室, 天津 300191 | sunyuebing@aepi.org.cn |
|
| 中文摘要 |
| 为强化海泡石（Sep）对溶液中Cd2+的吸附性能，采用酸碱复合改性处理获得改性海泡石（ABsep），借助氮气吸脱附等温线、SEM-EDS、TEM、FTIR和XRD等技术分析了改性前后海泡石的结构特征，采用静态吸附实验研究了时间、ABsep/Cd2+质量比、温度、吸附剂用量、pH及共存离子等因素对ABsep吸附Cd2+的影响.结果表明，ABsep孔隙结构发达，比表面积、平均孔径和孔容分别较改性前增加66.1%、15.7%和34.8%，可交换性离子含量有所增加，主要成分为SiO2和Mg（OH）2.改性前后海泡石对Cd2+吸附过程能较好地以准二级动力学方程和Langmuir模型进行拟合，且均为自发吸热反应，以化学吸附为主并伴有物理性吸附；最佳ABsep/Cd2+质量比为3：1；298 K时Sips拟合ABsep对Cd2+最大饱和吸附量为142.43 mg·g-1，为改性前海泡石的3.55倍；随着吸附剂投加量的增加，Cd2+吸附量表现为先增大后减小，最佳用量为0.3 g·L-1；ABsep对Cd2+的吸附量随溶液初始pH的升高而增加，最佳pH为7；不同浓度K+、Na+、Mg2+和Ca2+的存在均会对Cd2+的吸附产生一定的抑制作用，其中Mg2+的抑制作用最强. |
| 英文摘要 |
| To enhance the adsorption capacity of sepiolite (Sep) on Cd2+ in solution, an acid-base Sep (ABsep) was obtained using the method of combined acid-base modification. The structural properties of Sep and ABsep were analyzed by adsorption-desorption isotherms of N2, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD). Static adsorption experiments were carried out to evaluate the effects of time, mass ratio of ABsep/Cd2+, temperature, adsorbent dose, pH, and co-existing ions on the adsorption of Cd2+ by ABsep. The results showed that the pore structure of the ABsep was more developed than that of Sep. In comparison to Sep, the specific surface area, average pore diameter, and pore volume of ABsep increased by 66.1%, 15.7%, and 34.8%, respectively, and the exchangeable ion contents also increased. The main components of the ABsep were SiO2 and Mg(OH)2. The adsorption process of Cd2+ by Sep and ABsep could be well fitted with a pseudo-second-order kinetic equation and Langmuir isotherm, and both were spontaneous endothermic reactions, which were mainly chemical adsorption along with physical adsorption. The best mass ratio of ABsep:Cd2+ was 3:1, and the maximum saturated adsorption capacity fitted by the Sips model of the ABsep on Cd2+ at 298 K was 142.43 mg·g-1, which was 3.55 times that of Sep. As the adsorbent dose increased, the adsorption amounts of Cd2+ first increased and then decreased, with the optimum dose being 0.3 g·L-1. The amount of Cd2+ adsorption by the ABsep increased with the initial pH of the solution, whereby the best pH was 7. We also found that the presence of K+, Na+, Mg2+, and Ca2+ at different concentrations could inhibit the adsorption of Cd2+, whereby the inhibition of Mg2+ was the highest. |
|
|
|
