Abstract

The present study is aimed at investigating the change in surface morphology, hydraulic behaviour and sorption capability of two locally available Indian bentonites in the presence of different lead (Pb²⁺) concentrations. FESEM, FTIR, and EDX studies were conducted to analyse the change in surface morphology, alteration in FTIR pattern and decrease in exchangeable cation in both the bentonites before and after sorption of Pb²⁺. The tests were conducted in a batch mode to optimise operation parameters; pH, initial concentration, adsorbent dosage, and contact time. Equilibrium isotherm and sorption kinetics of both the bentonites were studied using various isotherm as well as kinetic models. The equilibrium data for both the bentonites were found to be the best fit for the Freundlich model. Both the bentonites followed Pseudo-second order equation. Hydraulic conductivity analysis illustrates that with the rise in Pb²⁺ concentration, the hydraulic conductivity increased for both the bentonite. The experimental evidence revealed that bentonite having high cation exchange capacity (CEC), swelling behaviour and high specific surface area (SSA) exhibits higher adsorption and heavy metal removal at 2000 mg/L of initial concentration of Pb²⁺ solution.

摘要

本研究旨在调查两种当地可用的印度膨润土在不同铅 (Pb ²⁺ ) 浓度存在下的表面形态、水力行为和吸附能力的变化。^{进行了 FESEM、FTIR 和 EDX 研究，以分析吸附 Pb 2+}前后膨润土中表面形态的变化、FTIR 图案的改变和可交换阳离子的减少。. 测试以批处理模式进行，以优化操作参数；pH、初始浓度、吸附剂用量和接触时间。使用各种等温线和动力学模型研究了两种膨润土的平衡等温线和吸附动力学。发现两种膨润土的平衡数据最适合 Freundlich 模型。两种膨润土都遵循伪二级方程。水力传导率分析表明，随着 Pb ²⁺浓度的增加，两种膨润土的水力传导率都增加了。实验证据表明，具有高阳离子交换容量 (CEC)、溶胀行为和高比表面积 (SSA) 的膨润土在 Pb 初始浓度为 2000 mg/L 时表现出更高的吸附和重金属去除率。²⁺解决方案。