Abstract

In this work, a melamine-based covalent organic framework (COF) was synthesized. Then its performance as a potential adsorbent for the removal of tetracycline (TC) was scrutinized by density functional theory computations. The theoretical results showed that TC interaction with COF is experimentally possible, exothermic, spontaneous, and thermodynamically favorable. The adsorption mechanism was checked out by natural bond orbital computations, the results of which demonstrated that TC interaction with COF is a physisorption process. The influence of temperature and the presence of the solvent was also investigated computationally, and the results showed that these parameters do not affect the interactions. Afterward, all effective operational parameters, including the amount of COF, agitation time, and pH, were optimized by the one-factor-at-a-time method to achieve the highest efficiency. Under optimum conditions, the experimental data were fitted to Langmuir, Freundlich, and Sips models. The TC adsorption behavior was well-described by the Sips isotherm with a maximum adsorption capacity of 168.98 mg/g. The desorption process was also discussed, and a mixture of methanol and acetic acid was selected as the most suitable desorption solvent.

中文翻译：

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三聚氰胺基共价有机框架快速高效去除四环素：综合密度泛函理论和实验研究

摘要

在这项工作中，合成了基于三聚氰胺的共价有机骨架（COF ）。然后通过密度泛函理论计算对其作为去除四环素 ( TC ) 的潜在吸附剂的性能进行了仔细检查。理论结果表明，TC 与 COF 的相互作用在实验上是可行的，是放热的、自发的，并且在热力学上是有利的。通过自然键轨道计算验证了吸附机理，结果表明TC与COF的相互作用是一个物理吸附过程。还通过计算研究了温度和溶剂存在的影响，结果表明这些参数不会影响相互作用。随后，所有有效的操作参数，包括 COF 量、搅拌时间和 pH 值，均通过一次一因素的方法进行优化，以实现最高效率。在最佳条件下，将实验数据拟合到Langmuir、Freundlich和Sips模型中。 Sips等温线很好地描述了TC的吸附行为，最大吸附容量为168.98 mg/g。对解吸过程进行了讨论，选择甲醇和乙酸的混合物作为最合适的解吸溶剂。