Mechanism of selective separation on the surface of ionic sieve of removal of lead

This note describes a kind of ionic sieve with high selectivity to remove trace lead in water, in which stannic molybdopyrophosphate is used to be the substrate. The mechanism of selective separation on the surface of ionic sieve of removal of lead was explored by analyzing fourier transformation infrared spectra (FTIR), X-ray photoelectron spectrometry (XPS) and the results of selective adsorptivity experiment. The investigation suggests that in the process of synthesizing ionic sieve the olation reactions occur in solid phase by thermodynamic recrystallization and the adsorption units with special selectivity to lead are formed by chemical modification. After the ion exchange for Pb2+, the oaltion reactions not only keep the microstructures of adsorption units from collapse, but also provide lead cavties with special selectivity to lead ion that are capable of having special binding 'memory effect' to Pb2+ by SnO32- and P2O74- groups on the surface of this ionic sieve. Meanwhile, the selective

Physicochemical Behaviour and Removal of Lead in Water

A new ionic sieve has been prepared in a process of saturating a substrate with Pb(Ac)_2 solution followed by thermodynamic recrystallization.The substrate is silica gel on which β-type titanium is introduced.The ionic sieve possesses a specific selectivity for Pb(Ⅱ)ions in the aqueous solution with mul- ticomponent composition.The aquatic chemistry of Pb(Ⅱ),the amphoteric surface of the ionic sieve and the behaviour of Pb(Ⅱ)at the solid-liquid interface are discussed.The ionic sieve can be used to remove lead from various aquatic systems.

改性天然沸石用于饮用水体除铅机理探讨

改性天然沸石是一种有效的水体脱铅离子筛。研究了天然沸石的改性，铅吸附性能，并对水体脱铅机理进行了探讨。

功能化介孔硅分子筛吸附剂除磷性能的研究

分别在甲基二甲氧基硅烷改性介孔分子筛MCM41上锚定Al和Fe离子,成功制备了功能化的介孔硅分子筛有机/无机杂化吸附剂Al-NN-MCM41和Fe-NN-MCM41。详细考察了磷溶液初始浓度、吸附时间,溶液pH值和共存离子等对吸附剂磷吸附性能的影响。实验结果表明:Langmiur等温方程比Freundlich等温方程能更好地描述磷酸根离子在两种吸附剂上的吸附,两种吸附剂的吸附动力学过程更适合动力学准二级方程(r2>0.99)。磷溶液的pH值对吸附剂的磷吸附容量有显著影响。此外,同时添加NO33-、Cl-、SO42-、CO32-四种共存离子对吸附剂磷吸附效率没有显著影响。

用13X分子筛去除废水中Pb^(2+)的研究

用13X分子筛作为去除铅离子吸附剂,研究各实验条件下对废水中Pb^(2+)的去除效果。考查了废水的pH、Pb^(2+)起始浓度对去除率的影响,Pb^(2+)起始浓度和吸附时间对吸附容量的影响。优化最佳条件为:控制废水的pH=8,Pb^(2+)浓度为200mg/L,搅拌时间为30min,分子筛投加量在5~6g/L时,13X分子筛对Pb^(2+)的去除率可达到92%左右。研究表明,13X分子筛对Pb^(2+)的吸附机理以离子交换吸附为主,符合Langmuir等温吸附模型。

离子印迹选择性吸附去除碱性蚀刻废液中的铅

采用水热辅助表面印迹技术,制备了铅离子印迹硅胶,利用红外光谱表征了其表面官能团,采用平衡吸附法研究了铅离子印迹硅胶对碱性蚀刻废液中铅的吸附性能和选择脱除能力。结果表明,在298K时,铅离子印迹硅胶对铅的最大吸附量为57.8 mg·g^(-1);脱除碱性蚀刻废液中铅时,铅离子印迹硅胶的优选剂量为8 g·L^(-1);在298K时,脱除时间为120 min;铅离子印迹硅胶在碱性蚀刻废液中脱除铅时显示出良好的选择性,铅的脱除率达到97.2%;铅离子印迹硅胶再生5次后,对铅的脱除率仍能达到88%以上;用净化后的碱性蚀刻废液所生产的碱式氯化铜中铅的含量为5.8±2.1 mg·kg^(-1),符合饲料级铜添加剂的标准。

氨基和巯基功能化合成的X分子筛高效去除Pb(Ⅱ)

为了提高X分子筛(XM)的耐酸性和对Pb^(2+)的吸附能力,采用有机改性剂对合成的XM进行了氨基功能化(NH_(2)-XM)和巯基功能化(SH-XM)改性。确定了最佳接枝条件,并对三种材料进行了表征和吸附研究。结果表明,三种材料的吸附过程属于单层化学吸附。与XM(34 mg/g)相比,NH_(2)-XM(154 mg/g)和SH-XM(111 mg/g)在低pH条件下具有更好的吸附效果和更强的耐酸能力。因此,NH_(2)-XM可作为高效吸附剂去除水溶液中的Pb^(2+)。