零价锌去除水中四环素的研究

Study on removal of tetracycline in water by zero-valent zinc

为控制水中四环素(TC)的质量浓度,采用零价锌(ZVZ)去除TC,考察了不同投加量下ZVZ对TC的去除效果,采用液相色谱质谱联用仪(LC-MS)进行产物分析,使用傅里叶红外光谱(FT-IR)对ZVZ去除TC反应后的粉末进行表征。结果表明:ZVZ对TC有良好的去除效果,其反应机理为吸附。吸附动力学表明该反应更符合准二级动力学。热力学分析表明:在25,30℃时该吸附更符合Freundlich吸附等温模型;在40℃时更符合Langmuir吸附等温模型。热力学参数表明该吸附过程为自发放热过程。溶液pH越低,TC去除效果越好,大部分溶液中存在的离子能促进去除效果。在5次吸附-解吸循环后,ZVZ对TC的去除率保持在96%以上。研究成果为去除水中TC提供了一种新的方法,并为该方法的实际应用提供数据支持。

In order to control the concentration of tetracycline(TC)in the water,zero-valent zinc(ZVZ)powder was used to remove TC.The removal efficiencies of TC by ZVZ under different dosages were investigated.The products were analyzed by liquid chromatography-mass spectrometry(LC-MS).The powders after removing TC were characterized by Fourier transform infrared spectroscopy(FT-IR).The results showed that ZVZ had a good removal effect on TC mainly through adsorption.Adsorption kinetics showed that the reaction was more in line with quasi-second-order kinetics.Thermodynamic analysis showed that at 25℃or 30℃,the adsorption was more consistent with Freundlich adsorption isotherm model.While,at 40℃,the adsorption was in correspondence with Langmuir adsorption isotherm model.Thermodynamic parameters showed that the adsorption process was a self-exothermic process.The removal efficiency was better under lower pH condition and improved by most ions in solution.After five adsorption-desorption cycles,the removal rates of TC by ZVZ remained above 96%.It provides a new method for removing TC in water,and provides data support for the practical application of this method.