Davarnejad Reza, Afshar Saeedeh, Pirhadi Masoud, Mirhosseini Matineh
Department of Chemical Engineering, Faculty of Engineering, Arak University, Arak, 38156-8-8349, Iran.
Department of Chemical Engineering, Åbo Akademi University, Henrikinkatu 2, 20500, Turku, Finland.
Sci Rep. 2025 Jan 2;15(1):53. doi: 10.1038/s41598-024-83790-w.
In this research, fresh pistachio green shell as an agricultural waste was blended with activated carbon to study the adsorption process of mercury (II) from several aqueous solutions with various concentrations. Central Composite Design under Response Surface Methodology was statistically used to consider the independent variables involving pH, contact time, fresh pistachio green shell powder dosage, initial concentration of mercury (II) and activated carbon dosage effects on the mercury (II) removal. pH of 6.13, initial mercury (II) concentration of 36.68 g/l, fresh pistachio shell powder dosage of 9.21 g/l, activated carbon dosage of 7.25 g/l as an optimal operating conditions for 99.25% of mercury (II) removal was experimentally found. The adsorption kinetic models such as the pseudo-first order, pseudo-second order, Elovich, and intraparticle diffusion were examined. The pseudo-second-order model (with R ≈ 1) could properly investigate the adsorption process kinetics. The adsorption isothermal behavior was considered using the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. Langmuir isotherm model showed the best results demonstrating the blended adsorbent homogeneous surface. The activation energy for the adsorption process was obtained at 2.158 kJ/mol. Several morphological tests (such as SEM, XRD, FTIR and EDX) were done to investigate the porosity and surface area of adsorbent although interaction of surface functional groups and synergistic effects can also be considered by these tests. The fresh pistachio green shell powder blended with activated carbon could physically adsorb (physisorption process) mercury (II) from an aqueous wastewater.
在本研究中，将新鲜开心果绿壳作为农业废弃物与活性炭混合，以研究从几种不同浓度的水溶液中吸附汞（II）的过程。采用响应面法中的中心复合设计，从统计学角度考虑了自变量，包括pH值、接触时间、新鲜开心果绿壳粉末用量、汞（II）初始浓度以及活性炭用量对汞（II）去除效果的影响。通过实验发现，pH值为6.13、汞（II）初始浓度为36.68 g/l、新鲜开心果壳粉末用量为9.21 g/l、活性炭用量为7.25 g/l是去除99.25%汞（II）的最佳操作条件。考察了吸附动力学模型，如伪一级模型、伪二级模型、埃洛维奇模型和颗粒内扩散模型。伪二级模型（R≈1）能够较好地研究吸附过程动力学。使用朗缪尔等温线模型、弗伦德里希等温线模型、坦金等温线模型和杜比宁-拉杜舍维奇等温线模型来考虑吸附等温线行为。朗缪尔等温线模型显示出最佳结果，表明混合吸附剂表面均匀。吸附过程的活化能为2.158 kJ/mol。进行了几种形态学测试（如扫描电子显微镜、X射线衍射、傅里叶变换红外光谱和能谱分析），以研究吸附剂的孔隙率和表面积，尽管这些测试也可以考虑表面官能团的相互作用和协同效应。新鲜开心果绿壳粉末与活性炭混合后能够从含汞废水中物理吸附（物理吸附过程）汞（II）。
