Laboratory of Desalination and Water Treatement LR19ES01, Faculty of Sciences of Tunis, Tunis El Manar University, 2092, El Manar I, Tunisia; Department of Separation Science, Lappeenranta-Lahti University of Technology (LUT), Sammonkatu 12, FI-50130, Mikkeli, Finland.
Department of Separation Science, Lappeenranta-Lahti University of Technology (LUT), Sammonkatu 12, FI-50130, Mikkeli, Finland; Department of Environmental Engineering, University of Engineering and Technology, Taxila, Pakistan.
J Environ Sci (China). 2020 May;91:246-261. doi: 10.1016/j.jes.2020.01.028. Epub 2020 Feb 12.
This study focuses on the synthesis of nanocomposites named CCA and CZA that were prepared by the incorporation of cellulose (CL) in the Ca/Al and Zn/Al layered double hydroxide (LDH), respectively. These materials were then used for the uptake of As(III) and As(V) from aqueous medium. Characterization of both nanocomposites (CCA and CZA) was done using FTIR and Raman analysis to identify the functional groups, N adsorption-desorption isotherms to determine the specific surface area and pore geometry and XPS analysis to obtain the surface atomic composition. Some other characters were investigated using simultaneous TGA and DTA and elemental chemical analysis (CHNS/O). The crystallinity of the prepared nanocomposites was displayed by XRD patterns. Furthermore, the sheet-like structure of the LDHs and the irregularity of surface morphology with porous structure were observed by TEM and SEM microphotographs. Optimization of maximum adsorption capacity was adjusted using different parameters including pH, contact time and adsorbent dosage. The pseudo-second-order model was in good fitting with kinetics results. The adsorption isotherm results showed that CZA exhibits better adsorption capacity for As(III) than CCA and the Langmuir isotherm model described the data well for both nanocomposites. Thermodynamic studies illustrated the endothermic nature of CCA and exothermic nature on CZA, as well as the fact that the adsorption process is spontaneous. A real water sample collected from well located in Gabes (Tunisia), has also been treated. The obtained experimental results were confirmed that these sorbents are efficient for the treatment of hazardous toxic species such as.
本研究聚焦于通过将纤维素 (CL) 分别掺入到 Ca/Al 和 Zn/Al 层状双氢氧化物 (LDH) 中，制备出名为 CCA 和 CZA 的纳米复合材料。然后，这些材料被用于从水溶液中吸附 As(III) 和 As(V)。对两种纳米复合材料 (CCA 和 CZA) 进行了特征描述，使用 FTIR 和拉曼分析来识别官能团，使用 N 吸附-解吸等温线来确定比表面积和孔几何形状，使用 XPS 分析来获得表面原子组成。使用同步热重分析和差热分析以及元素化学分析 (CHNS/O) 研究了其他一些特性。通过 XRD 图谱显示了制备的纳米复合材料的结晶度。此外，通过 TEM 和 SEM 显微照片观察到 LDH 的片状结构和表面形态的不规则多孔结构。通过调整不同参数（包括 pH、接触时间和吸附剂剂量）来优化最大吸附容量。准二级动力学模型与动力学结果拟合良好。吸附等温线结果表明，CZA 对 As(III)的吸附容量优于 CCA，Langmuir 等温线模型很好地描述了两种纳米复合材料的数据。热力学研究表明 CCA 是吸热的，CZA 是放热的，吸附过程是自发的。还对取自突尼斯加贝斯 (Tunisia) 一口井的实际水样进行了处理。实验结果表明，这些吸附剂对处理危险有毒物质如 As(III) 和 As(V)等非常有效。
