Laboratory of Quantum and Statistical Physics, LR18ES18, Faculty of Sciences of Monastir, Monastir University, Monastir, Tunisia.
Instituto Tecnológico de Aguascalientes, 20256, Aguascalientes, Mexico.
Environ Sci Pollut Res Int. 2021 Jun;28(24):30943-30954. doi: 10.1007/s11356-021-12832-x. Epub 2021 Feb 16.
A theoretical physicochemical and thermodynamic investigation of the adsorption of heavy metals Zn, Cd, Ni, and Cuon carbon-based adsorbents was performed with statistical physics fundaments. Particularly, the experimental adsorption isotherms of heavy metal removal, at 30°C and pH 5, using adsorbents obtained from the pyrolysis of three biomasses (cauliflower cores, broccoli stalks, and coconut shell) were modelled and interpreted with a homogeneous statistical physics adsorption model. Calculations indicated that the heavy metal adsorption with these carbon-based materials was a multi-ionic process where several ions interact simultaneously with the same carboxylic functional group on the adsorbent surface. Adsorption capacities for these metal ions and adsorbents were correlated with electronegativity theory, which established that the adsorbate with the highest electronegativity was more readily adsorbed by the carboxylic functional groups available on the adsorbent surfaces. Also, the chemical compositions of biomass precursors explained achieved adsorption capacities for these metallic ions. The best adsorbent for heavy metal removal was obtained from CC biomass pyrolysis. Calculated adsorption energies for heavy metal removal could be associated with physisorption-type forces. Finally, the adsorption mechanism analysis was complemented with the determination of adsorption thermodynamic functions using the statistical physics.
采用统计物理基础，对基于碳的吸附剂吸附重金属 Zn、Cd、Ni 和 Cu 的理论物理化学和热力学进行了研究。特别是，使用三种生物质（菜花芯、西兰花茎和椰子壳）热解得到的吸附剂，在 30°C 和 pH 5 条件下，对重金属去除的实验吸附等温线进行了建模和解释，采用均匀统计物理吸附模型。计算表明，这些碳基材料对重金属的吸附是一个多离子过程，其中几个离子同时与吸附剂表面上的相同羧酸官能团相互作用。这些金属离子和吸附剂的吸附容量与电负性理论相关联，该理论表明，具有最高电负性的吸附物更容易被吸附剂表面上可用的羧酸官能团吸附。此外，生物质前体的化学成分解释了对这些金属离子的吸附能力。从 CC 生物质热解中获得了去除重金属的最佳吸附剂。计算出的重金属去除吸附能可与物理吸附型力相关联。最后，使用统计物理对吸附热力学函数进行了测定，从而补充了吸附机理分析。
