Kinetics and thermodynamics of lead (II) adsorption on lateritic nickel ores of Indian origin.
Kinetics and thermodynamics of lead (II) adsorption on lateritic nickel ores of Indian origin.
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DOI：
10.1016/j.cej.2009.07.035
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发表时间：
2009-12
影响因子：
15.1
通讯作者：
M. Mohapatra;S. Khatun;S. Anand
中科院分区：
文献类型：
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作者：
M. Mohapatra;S. Khatun;S. Anand
采用两种典型的印度红土镍矿（分别以NH和NL表示，含铁量分别为46.29%和28.56%），进行了水溶液中铅的吸附实验。吸附被认为是强烈依赖于介质的pH值显示增加的Pb（II）的摄取量从11.0%至53%和8.2%至44%的NH和NL样品分别与pH值的增加在2.0-5.23的范围内。两种样品在不同温度下的时间数据均符合二级动力学模型和Elovich方程。后者是化学吸附过程的指示。+ve ΔH°值（NH和NL样品为8.90和10.29kJmol− 1）支持吸附的吸热性质。+ve ΔS°值（NH和NL分别为28.56和29.40kJmol− 1 K − 1）表明吸附发生内部结构变化。NH和NL的活化能分别为7.6和3.12kJmol− 1。用Eyring方程计算了热力学活化参数。在吸附剂浓度为2gl-1、吸附时间为30 min、温度为308 K、pH值为5.23的实验条件下，NH和NL的负载量分别为44.4和28.45mgg-1。数据拟合以及Langmuir和Freundlich等温模型NH，而在NL的情况下，只有Langmuir等温线表现出良好的拟合。由于高负载能力和有利的动力学，这些材料可用于从水溶液中去除Pb（II）。
The lead adsorption from aqueous solution was studied in batch experiments using two typical Indian origin nickel lateritic ores having high (46.29%) and low iron content (28.56%) coded as NH and NL respectively. The adsorption was found to be strongly dependent on pH of the medium showing increase in uptake of Pb(II) from 11.0 to 53% and 8.2 to 44% for NH and NL samples respectively with the increase in pH in the range of 2.0–5.23. The time data generated at different temperatures for both the samples fitted well to second-order kinetic model and Elovich equation. The later is indicative of a chemisorption process. The +ve ΔH° values (8.90 and 10.29kJmol−1for NH and NL samples) support the endothermic nature of adsorption. The +ve ΔS° values (28.56 and 29.40kJmol−1K−1for NH and NL respectively) suggest that the adsorption occurs with internal structural changes. The activation energy was estimated to be 7.6 and 3.12kJmol−1for NH and NL respectively. The thermodynamic activation parameters were also evaluated using Eyring equation. The loading capacities of NH and NL were estimated to be 44.4 and 28.45mgg−1respectively under the experimental conditions: adsorbent concentration 2gl−1, time 30min, temperature 308K and pH 5.23. Data fitted well to Langmuir and Freundlich isotherm models for NH while in case of NL only Langmuir isotherm showed good fit. Due to high loading capacities and favorable kinetics, these materials can be utilized for Pb(II) removal from aqueous solutions.