Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China.
Environ Sci Pollut Res Int. 2019 Apr;26(10):10106-10116. doi: 10.1007/s11356-019-04466-x. Epub 2019 Feb 12.
Solid waste fly ash with low aluminum of Yunnan Province in China was used as pristine material to prepared chitosan-coated Na-X zeolite, and the obtained composite material was employed as As(V) adsorbent. Then, the prepared materials were characterized by XRD, FT-IR, and XPS. And the results suggested that the low aluminum fly ash was successfully convert into Na-X zeolite, and the mineralization between Si-OH of the obtained Na-X zeolite and C-OH of chitosan was the dominated mechanism for coated chitosan over the surface of Na-X zeolite. From the batch experiments of As(V) removal, it has been found that the coated chitosan could significantly improve As(V) performance of Na-X zeolite. The optimal working pH for removal As(V) by chitosan-coated Na-X zeolite was attained at pH 2.1 ± 0.1, and the maximum adsorption capacity was 63.23 mg/g. And the adsorption data at different interval time was excellent fitted by pseudo-second-order kinetic model. From the analyze of XPS, the results suggested that As(V) uptake over adsorbent by the bond of As-N and As-O and the surface hydroxyl group of Al-OH and -NH were involved in uptake As(V) from acid wastewater.
以中国云南省低铝的固体废物飞灰为原始材料，制备壳聚糖包覆的 Na-X 沸石，并将所得复合材料用作 As(V)吸附剂。然后，通过 XRD、FT-IR 和 XPS 对制备的材料进行了表征。结果表明，低铝飞灰成功转化为 Na-X 沸石，并且获得的 Na-X 沸石的 Si-OH 与壳聚糖的 C-OH 之间的矿化作用是壳聚糖包覆在 Na-X 沸石表面的主要机制。从去除 As(V)的批量实验中可以发现，壳聚糖包覆可以显著提高 Na-X 沸石对 As(V)的性能。去除 As(V)的最佳工作 pH 值在 pH 2.1 ± 0.1 时达到，最大吸附容量为 63.23 mg/g。不同间隔时间的吸附数据通过拟二级动力学模型得到了很好的拟合。从 XPS 的分析来看，结果表明，吸附剂上的 As(V)摄取是通过 As-N 和 As-O 的键合以及 Al-OH 和 -NH 的表面羟基参与的，从酸性废水中摄取 As(V)。
