缺陷Zr基金属有机框架材料的制备、表征及其对四环素的吸附性能研究

PREPARATION AND CHARACTERIZATION OF DEFECTIVE Zr-BASED METAL-ORGANIC FRAMEWORKS AND THEIR ADSORPTION PROPERTIES FOR TETRACYCLINE

吸附具有成本低、能耗小、操作方便和环境友好等优点,在污水净化领域具有广泛应用潜力。通过简单的溶剂热法制备了缺陷Zr基金属有机框架(UiO-66-NH_(2))吸附剂,并将其用于去除废水中四环素。利用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、傅立叶变换红外光谱(FT-IR)、氮气吸附-脱附和X射线光电子能谱等手段对吸附剂进行表征。为获得吸附剂去除废水中四环素最佳条件,以四环素的吸附量为响应值,在单因素实验基础上,采用Box-Behnken设计(BBD)响应曲面法(RSM)考察吸附剂投加量、溶液pH值、四环素初始浓度以及吸附时间等因素相互作用和影响。结果表明,经实验修正后的最佳吸附条件:吸附剂投加量为10 mg,pH=3.80,四环素初始浓度为27 mg/L,吸附时间为3 h;此条件下,吸附剂对四环素的吸附量可达71.85 mg/g。此外,再生实验表明,经过5次循环吸附后,吸附剂仍具有较强的吸附能力(68.33 mg/g),是一种相对稳定的吸附材料。

Adsorption has the potential to be broadly applied in the field of sewage purification due to advantages such as low costs,less energy consumption,ease of operation and environmental friendliness.In this work,Zr-based metal-organic frameworks(UiO-66-NH_(2))with defects were successfully prepared by a facile solvothermal method,which was used to removal tetracycline from wastewater.Defective UiO-66-NH_(2)was characterized by X-ray diffraction(XRD),field emission electron microscope(FESEM),Fourier transform infrared(FT-IR),nitrogen adsorption-desorption and X-ray photoelectron spectroscopy.In order to achieve optimum conditions of tetracycline from aqueous solutions,based on single-factor tests,response surface methodology(RSM)and Box-Behnken design(BBD)were employed to examine the interaction of factors and optimize the adsorption operation parameters,including adsorbent dose,the initial concentration of tetracyclines,pH and contact time.The optimum conditions of maximum adsorption(71.85 mg/g)were found as follows:10 mg of adsorbent dosage,initial tetracycline concentration of 27 mg/L,pH=3.8 and adsorption time of 3 h.In addition,regeneration experiments showed that the adsorption efficiency of tetracycline after five adsorption-desorption cycles with good uptake efficiency(68.33 mg/g)and UiO-66-NH_(2)exhibited quite a good cyclic stability.