Yavari Z, Noroozifar M
Department of Chemistry, University of Sistan and Baluchestan, P.O. Box 98155-147, Zahedan, Iran E-mail:
Water Sci Technol. 2017 Oct;76(7-8):2242-2253. doi: 10.2166/wst.2017.375.
In this study, black carbon from pine cone (BCPC) and acidic-modified BCPC (MBCPC) powder as a popular agricultural waste in the southeast of Iran were used for cadmium removal from aqueous solutions. The effect of various factors, such as surface chemistry and dosage of adsorbent, contact time, size of particles, initial concentration of cadmium, temperature, and pH of aqueous solutions, was investigated. The results show cadmium removal with usage of the mentioned adsorbents increased after acidic modification. It was noteworthy in this work that the removal percentage of pollutant was above 90% for suggested biosorbents. The obtained experimental data for optimum conditions were selected to model the adsorption behavior of the materials with usage of six isotherm equations via non-linear fitting method and the residual root mean square error estimation for each model. The adsorption of cadmium preferably fitted Khan and Langmuir-Freundlich isotherms for BCPC and MBCPC adsorbents, respectively. The kinetic studies via linear fitting method proved the second-order kinetic was the applicable model for the adsorption process. Thermodynamic studies show the adsorption process of cadmium onto BCPC and MBCPC was spontaneous and endothermic.
在本研究中，伊朗东南部一种常见的农业废弃物——松果黑碳（BCPC）和酸性改性的BCPC（MBCPC）粉末被用于从水溶液中去除镉。研究了各种因素的影响，如吸附剂的表面化学性质和用量、接触时间、颗粒大小、镉的初始浓度、温度以及水溶液的pH值。结果表明，酸性改性后，使用上述吸附剂去除镉的效果有所提高。在这项工作中值得注意的是，对于所建议的生物吸附剂，污染物的去除率高于90%。选择在最佳条件下获得的实验数据，通过非线性拟合方法使用六个等温方程对材料的吸附行为进行建模，并对每个模型进行残差均方根误差估计。镉的吸附分别对BCPC和MBCPC吸附剂最好地拟合了Khan等温线和Langmuir-Freundlich等温线。通过线性拟合方法进行的动力学研究证明，二级动力学是吸附过程适用的模型。热力学研究表明，镉在BCPC和MBCPC上的吸附过程是自发的且吸热的。
