Abstract In this study, an adsorptive ceramic membrane coated by new layer of cage-like mesoporous silica SBA_16 which was modified with 3-aminopropyltriethoxysilane (APTES) was employed to remove (Cr (VI)) ions from aqueous solution. The morphologies and physiochemical properties of SBA_16 and modified SBA_16 (NH2-SBA_16) adsorbents as well as adsorptive membranes were characterized through thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), N2 adsorption-desorption isotherms, X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The adsorption isotherm data perfectly was fitted to Langmuir isotherm model and the adsorption capacity value of NH2-SBA_16 for Cr (VI) at pH of 2.5 was 61.9 mg/g. The experimental kinetic data agreed with pseudo-second-order model. The dynamic filtration test in dead-end system was utilized to evaluate the efficiency of ceramic membranes in hexavalent chromium removal. The modification of ceramic membrane (CM2) resulted in an excellent Cr (VI) removal (100 %) for permeate stream. Aminopropyl grafting on the ceramic membrane significantly enhanced the permeate flux from 56 L/m2h to 85.6 L/m2h. Density functional theory (DFT) calculations have been performed and the adsorption energy of Cr (VI) on NH2-SBA_16 was obtained 131.25 kJ/mol.

中文翻译：

---

双层吸附陶瓷膜支持笼状介孔二氧化硅去除六价铬：实验和 DFT 研究

摘要 在本研究中，采用3-氨基丙基三乙氧基硅烷（APTES）改性的新型笼状介孔二氧化硅SBA_16包覆的吸附陶瓷膜去除水溶液中的（Cr（VI））离子。通过热重分析 (TGA)、傅里叶变换红外 (FTIR)、N2 吸附-解吸等温线、X 射线衍射 (XRD) 表征 SBA_16 和改性 SBA_16 (NH2-SBA_16) 吸附剂以及吸附膜的形貌和理化性质。 ) 和场发射扫描电子显微镜 (FESEM)。吸附等温线数据完全符合Langmuir等温线模型，NH2-SBA_16对Cr(VI)在pH 2.5时的吸附容量值为61.9 mg/g。实验动力学数据与伪二级模型一致。利用死端系统动态过滤试验评价陶瓷膜去除六价铬的效率。陶瓷膜 (CM2) 的改性使渗透流的 Cr (VI) 去除率达到 100%。陶瓷膜上的氨基丙基接枝显着提高了渗透通量，从 56 L/m2h 提高到 85.6 L/m2h。进行了密度泛函理论（DFT）计算，得到 NH2-SBA_16 上 Cr (VI) 的吸附能为 131.25 kJ/mol。