Incorporating attapulgite nanorods into graphene oxide nanofiltration membranes for efficient dyes wastewater treatment
Incorporating attapulgite nanorods into graphene oxide nanofiltration membranes for efficient dyes wastewater treatment
复制标题
将凹凸棒石纳米棒融入氧化石墨烯纳滤膜中，用于高效处理染料废水
DOI：
10.1016/j.seppur.2018.04.079
复制
发表时间：
2019-05-01
影响因子：
8.6
通讯作者：
Zhang, Xiao-Liang
中科院分区：
文献类型：
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作者：
Wang, Cai-Yun;Zeng, Wen-Juan;Zhang, Xiao-Liang
采用真空辅助过滤技术成功制备了氧化石墨烯/凹凸棒石(GO/APT)复合膜，用于染料废水的高效处理。通过红外光谱、X射线光电子能谱、拉曼光谱、X-射线衍射仪和场发射扫描电子显微镜的表征，证实了APT纳米棒通过接枝改性形成了GO层间距(d-间距)、膜表面微观结构(层形态、结构和亲水性)甚至水分离性能。与原始GO膜相比，随着APT/GO比例的增加，GO/APT膜的d间距从0.90 nm逐渐增大到1.07 nm，而水接触角从71.0°减小到43.3°。此外，GO/APT膜具有粗糙的层次化结构和较高的表面亲水性，这与较大的层间距相结合，可以协同提高分离性能。在优化条件下，GO膜的水渗透通量从GO膜的3.4提高到GO/APT膜的13.3 L m(-2)h(-1)，对7.5mgL-1 Rh B废水的截留率接近100%。同样，膜厚度、染料浓度和料液中的分离物种也会影响膜的分离性能。通过GO/APT纳滤膜的协同分离机理：形成三维网状层状结构的畅通水通道的尺寸排斥效应，以及膜表面含氧官能团与带电分子之间的静电相互作用，有效地去除了染料分子。这些GO/APT膜表现出高效的分离性能，为其在水净化和染料废水处理中的潜在应用提供了新的视角。
Graphene oxide/attapulgite (GO/APT) composite membranes were successfully fabricated by the vacuum-assisted filtration for efficient dyes wastewater treatment. By characterization of FTIR, XPS, Raman, XRD and FESEM, APT nanorods were confirmed to be incorporated into GO laminar layers via grafting modification, which would influence GO interlayer distance (d-spacing), membrane surface microstructure (laminate morphology, structure, and hydrophilicity) and even water separation performance. Comparison of those of pristine GO membrane, the calculated d-spacing of GO/APT membranes gradually increased from 0.90 rim to 1.07 nm, while water contact angles decreased from 71.0 degrees to 43.3 degrees with the increasing APT/GO ratios. Moreover, GO/APT membranes exhibited rough hierarchical microstructure and higher surface hydrophilicity, which was in conjunction with larger interlayer spacing to synergistically improve separation performance. The water permeated flux increased from 3.4 of pristine GO membrane to 13.3 L m(-2) h(-1) of GO/APT membrane with preserving high rejection nearly to 100% for 7.5 mg L-1 Rh B wastewater under optimized conditions. Similarly, membrane thickness, dye concentrations and separating species in feed solutions were also found to affect membrane separation performance. Dye molecules were efficiently rejected through GO/APT nanofiltration membranes by the synergistic separation mechanism: size exclusion effect because of the unimpeded water channels formed into 3D network laminate structure, and electrostatic interactions between the oxygen-containing functional groups on membrane surface and charged molecules. Such these GO/APT membranes demonstrated efficiently separation properties and thus provided new insight into the potential applications in water purification and dyes wastewater treatment.