Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran.
Department of Soil Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran.
Environ Sci Pollut Res Int. 2023 Nov;30(51):110515-110527. doi: 10.1007/s11356-023-29963-y. Epub 2023 Oct 4.
In the study, an adsorptive removal strategy as a straightforward and fast procedure was developed to remove four aflatoxins, including aflatoxin B1 (AF-B1), aflatoxin B2 (AF-B2), aflatoxin G1 (AF-G1), and aflatoxin G2 (AF-G2). A simple and green sorbent consisting of two components (activated nanobentonite and FeO nanoparticles) was synthesized based on three steps using acidic treatment, ultrasonic procedure, and chemical precipitation method. The sorbent was characterized by several techniques such as FTIR, FESEM, TEM, XRD, and VSM to determine the sorbent structure and morphology. An experimental design based on a central composite design was utilized to optimize factors in the removal of AFs. The optimum values of the factors (pH, sorbent amount, shaking rate) were 6.8, 0.076 g, and 160 rpm, respectively. Three models, including pseudo-first-order, pseudo-second-order, and intra-particle diffusion models, were used to investigate the kinetics of the removal process. The removal of AFs using magnetic nanobentonite was fitted with the pseudo-second-order model better than other models with an equilibrium time lower than 30 min. The thermodynamic data show that the adsorption of AFs on the sorbent is a spontaneous and feasible process due to negative values of the Gibbs-free energy change (ΔG) at different temperatures. Two models (Langmuir and Freundlich models) were chosen to study the isotherm of the removal procedure, indicating that the Freundlich model describes the results better than the Langmuir model. The maximum adsorption capacity of the sorbent for removing AF-B1, AF-B2, AF-G1, and AF-G2 is 357.14, 400.0, 370.37, and 400.0 mg g, respectively. The sorbent reusability was also evaluated to study the sorbent's ability for the removal of AFs, indicating that the sorbent was used for 5 cycles without a significant reduction in the ability to remove AFs.
在这项研究中，开发了一种吸附去除策略，作为一种简单快速的方法来去除四种黄曲霉毒素，包括黄曲霉毒素 B1（AF-B1）、黄曲霉毒素 B2（AF-B2）、黄曲霉毒素 G1（AF-G1）和黄曲霉毒素 G2（AF-G2）。基于酸处理、超声处理和化学沉淀法这三个步骤，合成了一种由两种成分（纳米活性膨润土和 FeO 纳米粒子）组成的简单绿色吸附剂。通过傅里叶变换红外光谱（FTIR）、场发射扫描电子显微镜（FESEM）、透射电子显微镜（TEM）、X 射线衍射（XRD）和振动样品磁强计（VSM）等技术对吸附剂的结构和形貌进行了表征。利用中心组合设计实验设计来优化去除 AFs 的因素。去除 AFs 的最佳因素值（pH、吸附剂用量、搅拌速率）分别为 6.8、0.076g 和 160rpm。采用准一级、准二级和内扩散模型三种模型研究了去除过程的动力学。使用磁性纳米膨润土去除 AFs 的过程更符合准二级模型，平衡时间低于 30min。热力学数据表明，由于不同温度下吉布斯自由能变化（ΔG）的负值，吸附剂对 AFs 的吸附是一个自发可行的过程。选择了两种模型（朗缪尔和弗伦德利希模型）来研究去除过程的等温线，表明弗伦德利希模型比朗缪尔模型更好地描述了结果。吸附剂对去除 AF-B1、AF-B2、AF-G1 和 AF-G2 的最大吸附容量分别为 357.14、400.0、370.37 和 400.0mg/g。还评估了吸附剂的可重复使用性，以研究其去除 AFs 的能力，表明吸附剂在 5 个循环中使用，去除 AFs 的能力没有显著降低。
