Liu Hang, Han Caiyun, Yang Liu, Liu Dekun, Luo Yongming
Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China E-mail:
Water Sci Technol. 2018 Feb;77(3-4):871-879. doi: 10.2166/wst.2017.601.
Contaminant arsenic(V) has been regarded as one of the top-priority pollutants to remove from water. In this contribution, different mesoporous Y-Al binary oxides were prepared by the wet impregnation method via varying the molar ratio of Y/Al in the range of 0.029 to 0.116. The manufactured materials were employed as adsorbent to separate arsenic(V) from water. The adsorbent was characterized by N adsorption-desorption isotherm, point of zero charge (PZC) and Fourier transform infrared (FT-IR). Furthermore, the effect of experimental parameters on adsorption performance was evaluated by batch experiments, including the molar ratio of Y/Al, adsorbent dosages and contact time, initial concentration, initial pH and temperature. The results indicated that the adsorbent presented an optimal adsorption performance for As(V) uptake when the molar ratio of Y/Al was 0.058. The obtained experimental data were best fitted by Langmuir isotherm and the maximum adsorption capacity was 60.93 mg/g at pH 6.6 ± 0.1. Additionally, according to the results of adsorption kinetics, it was pronounced that adsorption process was complied with pseudo-second-order model. The adsorption thermodynamic suggested that the adsorption of As(V) is endothermic and spontaneous natural. Moreover, based on the results of FT-IR, PZC and initial pH, it is demonstrated that ion-exchange and electrostatic interaction were the dominating adsorption mechanism.
污染物五价砷被视为水中需优先去除的污染物之一。在本研究中，通过湿浸渍法，在0.029至0.116的Y/Al摩尔比范围内制备了不同的介孔Y-Al二元氧化物。所制备的材料用作吸附剂以从水中分离五价砷。通过N吸附-脱附等温线、零电荷点（PZC）和傅里叶变换红外光谱（FT-IR）对吸附剂进行了表征。此外，通过批量实验评估了实验参数对吸附性能的影响，这些参数包括Y/Al摩尔比、吸附剂用量、接触时间、初始浓度、初始pH值和温度。结果表明，当Y/Al摩尔比为0.058时，吸附剂对五价砷的吸附表现出最佳性能。所获得的实验数据最符合朗缪尔等温线，在pH 6.6±0.1时最大吸附容量为60.93 mg/g。此外，根据吸附动力学结果，明显表明吸附过程符合准二级模型。吸附热力学表明，五价砷的吸附是吸热且自发的自然过程。而且，基于FT-IR、PZC和初始pH值的结果，证明离子交换和静电相互作用是主要的吸附机制。
