Bakhsh Esraa M, Bilal Muhammad, Ali Maqsood, Ali Javed, Wahab Abdul, Akhtar Kalsoom, Fagieh Taghreed M, Danish Ekram Y, Asiri Abdullah M, Khan Sher Bahadar
Department of Chemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
Department of Chemistry, Kohat University of Science & Technology, Kohat 26000, Khyber Pakhtunkhwa, Pakistan.
Materials (Basel). 2022 Mar 8;15(6):1986. doi: 10.3390/ma15061986.
The removal of dyes from industrial effluents is one of the most important industrial processes that is currently on academic demand. In this project, for the first time, seeds are used as biosources for the synthesis of activated carbon (AC) using physical as well as acid-base chemical methods. The synthesized AC was initially characterized by different instrumental techniques, such as FTIR, BET isotherm, SEM, EDX and XRD. Then, the prepared activated carbon was used as an economical adsorbent for the removal of xylenol orange and thymol blue from an aqueous solution. Furthermore, the effect of different parameters, i.e., concentration of dye, contact time, pH, adsorbent amount, temperature, adsorbent size and agitation speed, were investigated in batch experiments at room temperature. The analysis of different techniques concluded that the pyrolysis method created a significant change in the chemical composition of the prepared AC and the acid-treated AC offered a high carbon/oxygen composite, which is graphitic in nature. The removal of both dyes (xylenol orange and thymol blue) was increased with the increase in the dye's initial concentration. Isothermal data suggested that the adsorption of both dyes follows the Langmuir model compared to the Freundlich model. The equilibrium time for AC biomass to achieve the removal of xylenol orange and thymol blue dyes was determined to be 60 min, and the kinetic data suggested that the adsorption of both dyes obeyed the pseudo-second order model. The optimal pH for thymol blue adsorption was pH 6, while it was pH 2 for xylenol orange. The adsorption of both dyes increased with the increase in the temperature. The influence of the adsorbent amount indicated that the adsorption capacity (mg/g) of both dyes reduced with the rise in the adsorbent amount. Thus, the current study suggests that AC prepared by an acid treatment from seeds is a good, alternative, cost effective, and eco-friendly adsorbent for the effective removal of dyes from polluted water.
从工业废水中去除染料是当前学术研究中最重要的工业过程之一。在本项目中，首次将种子用作生物源，采用物理以及酸碱化学方法合成活性炭（AC）。合成的AC最初通过不同的仪器技术进行表征，如傅里叶变换红外光谱（FTIR）、BET等温线、扫描电子显微镜（SEM）、能量散射X射线谱（EDX）和X射线衍射（XRD）。然后，将制备的活性炭用作经济吸附剂，从水溶液中去除二甲苯酚橙和百里酚蓝。此外，在室温下进行的批量实验中，研究了不同参数的影响，即染料浓度、接触时间、pH值、吸附剂用量、温度、吸附剂尺寸和搅拌速度。不同技术的分析得出结论，热解方法使制备的AC的化学成分发生了显著变化，酸处理的AC提供了高碳/氧复合材料，其本质上是石墨状的。两种染料（二甲苯酚橙和百里酚蓝）的去除率随染料初始浓度的增加而提高。等温数据表明，与弗伦德利希模型相比，两种染料的吸附均遵循朗缪尔模型。确定AC生物质实现去除二甲苯酚橙和百里酚蓝染料的平衡时间为60分钟，动力学数据表明两种染料的吸附均符合准二级模型。百里酚蓝吸附的最佳pH值为6，而二甲苯酚橙的最佳pH值为2。两种染料的吸附率随温度的升高而增加。吸附剂用量的影响表明，两种染料的吸附容量（mg/g）随吸附剂用量的增加而降低。因此，当前研究表明，通过酸处理种子制备的AC是一种良好的、替代的、具有成本效益且环保的吸附剂，可有效去除污染水中的染料。
