Abstract

In this study, graphene oxide and composites of graphene oxide-iron modified clinoptilolite were synthesized and used for arsenate removal from aqueous solution. All adsorbents were characterized using X-ray diffraction and specific surface area analysis. The specific surface areas of composites were found to be less than the iron modified clinoptilolite. The time required to reach equilibrium was determined as 3 hours for all adsorbents. The Box-Behnken statistical experiment design method was used to determine the effects of initial arsenate concentration, pH and the amount of adsorbent on the percent arsenate removal. Graphene oxide was not as effective as composites for arsenate adsorption from water. Arsenate adsorption on composites was showed good compatibility with the Freundlich isotherm. The maximum arsenate uptake was realized at pH 4 for graphene oxide and at pH 7 for composites. The maximum adsorption capacities obtained at the optimum points determined by using the Box-Behnken design method were calculated as 39.49, 117.98 and 124.64 µg.g⁻¹ for graphene oxide and composites, respectively.

摘要

在这项研究中，氧化石墨烯和氧化石墨烯-铁改性斜发沸石的复合材料被合成并用于从水溶液中去除砷。使用X射线衍射和比表面积分析对所有吸附剂进行表征。发现复合材料的比表面积小于铁改性斜发沸石。对于所有吸附剂，达到平衡所需的时间确定为3小时。使用Box-Behnken统计实验设计方法确定初始砷酸盐浓度，pH和吸附剂含量对砷去除百分率的影响。氧化石墨烯不能像复合物那样有效地从水中吸附砷。砷酸盐在复合材料上的吸附表现出与Freundlich等温线的良好相容性。在氧化石墨烯的pH 4和复合材料的pH 7时，砷的最大吸收量得以实现。通过Box-Behnken设计方法确定的最佳点处获得的最大吸附容量计算为39.49、117.98和124.64 µg.g^-1分别用于氧化石墨烯和复合材料。