Kaolinite and methoxy-modified kaolinite were used as novel adsorbents for oxytetracycline (OTC) removal and recovery from aqueous media. Batch adsorption experiments were performed to study the effect of pH, ionic strengths, initial concentration, and contact time on OTC adsorption. The adsorbents were characterized using powder X-ray diffraction (PXRD), Fourier-transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) before and after adsorption. Adsorption of OTC reached its maximum when solution pH increased up to 6 for 0.001 M ionic strength, above which adsorption decreased further when solution pH increased. Freundlich and Langmuir’s models best fit the equilibrium data with a strong dependency on OTC adsorption capacity giving its maximum at 36 mg g⁻¹. Binding is postulated for OTC adsorption on pristine kaolinite as a special case of Hill model with independent binding interaction of OTC adsorption onto the clay that affects the adjacent sites on the pristine kaolinite, in contrast with the adsorption of OTC on methoxy-modified kaolinite. Nitrogen peaks of the XPS spectra indicated changes in the oxidation states of C–N bonds in the N1s peaks by forming tertiary amide C–N and methoxy O–CH₃ bonds which corroborated with the results from FTIR spectra. Removal efficiencies and spectroscopic results indicate that performance on methoxy-modified kaolinite is a promising modification on the clay for recovering antibiotics from wastewater.

高岭石和甲氧基改性的高岭石被用作从土相介质中去除土霉素和回收土霉素的新型吸附剂。进行了批量吸附实验，以研究pH值，离子强度，初始浓度和接触时间对OTC吸附的影响。吸附前后使用粉末X射线衍射（PXRD），傅里叶变换红外（FTIR）光谱和X射线光电子能谱（XPS）对吸附剂进行表征。在0.001 M的离子强度下，当溶液的pH值增加到6时，OTC的吸附达到最大值，当溶液pH升高时，其吸附量进一步降低。Freundlich和Langmuir的模型最适合平衡数据，并且强烈依赖于OTC吸附能力，最大吸附量为36 mg g ^-1。假定结合原始OTC在原始高岭土上的吸附，这是Hill模型的特殊情况，OTC吸附在粘土上的独立结合相互作用会影响原始高岭石的相邻位点，而OTC在甲氧基改性的高岭石上的吸附则相反。XPS光谱的氮峰表明，通过形成叔酰胺C–N和甲氧基O–CH ₃键，N1s峰中C–N键的氧化态发生了变化，这与FTIR光谱的结果相符。去除效率和光谱结果表明，在甲氧基改性的高岭石上的性能是粘土上用于从废水中回收抗生素的有前途的改性。