College of Chemistry and Chemical Engineering, Central South University, Changsha, 410083, Hunan, People's Republic of China.
Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety, Central South University, Changsha, 410083, Hunan, People's Republic of China.
Environ Sci Pollut Res Int. 2022 Nov;29(51):77851-77863. doi: 10.1007/s11356-022-20701-4. Epub 2022 Jun 10.
Fe(III)-chitosan and Fe(III)-chitosan-CTAB composites were prepared using an ionotropic gelation method. Various techniques were used to analyze the morphology, structure, and property of the adsorbents, including SEM, EDS, FT-IR, XPS, and zeta potential. Compared with Fe(III)-chitosan, Fe(III)-chitosan-CTAB was more effective for As(V) adsorption at a wide range of pH (3.0-8.0). The adsorption of As(V) onto Fe(III)-chitosan and Fe(III)-chitosan-CTAB could reach equilibrium in 20 min, and their maximum adsorption capacities were 33.85 and 31.69 mg g, respectively. The adsorption kinetics was best described by the pseudo-second-order model (R = 0.998 and 0.992), whereas the adsorption isotherm was fitted well by the Freundlich model (R = 0.963 and 0.987). The presence of HPO significantly inhibited the adsorption of As(V) onto Fe(III)-chitosan and Fe(III)-chitosan-CTAB, and humic acid also led to a slight decrease in As(V) adsorption by Fe(III)-chitosan-CTAB. Over 94% of As(V) at the initial concentration of no more than 5 mg L was removed from real water by the two adsorbents. 1% (w/v) NaOH solution was determined to be the most suitable desorption agent. Fe(III)-chitosan and Fe(III)-chitosan-CTAB still maintained their initial adsorption capacities after five adsorption-desorption cycles. Based on different characterization results, both electrostatic attraction and surface complexation mechanisms played important roles in As(V) adsorption on Fe(III)-chitosan and Fe(III)-chitosan-CTAB.
采用离子凝胶法制备了 Fe(III)-壳聚糖和 Fe(III)-壳聚糖-CTAB 复合材料。采用 SEM、EDS、FT-IR、XPS 和zeta 电位等多种技术对吸附剂的形貌、结构和性能进行了分析。与 Fe(III)-壳聚糖相比，Fe(III)-壳聚糖-CTAB 在较宽的 pH（3.0-8.0）范围内对 As(V)的吸附更有效。As(V)在 Fe(III)-壳聚糖和 Fe(III)-壳聚糖-CTAB 上的吸附在 20 分钟内达到平衡，最大吸附容量分别为 33.85 和 31.69mg/g。吸附动力学最好用伪二级模型（R=0.998 和 0.992）描述，而吸附等温线很好地符合 Freundlich 模型（R=0.963 和 0.987）。HPO 的存在显著抑制了 As(V)在 Fe(III)-壳聚糖和 Fe(III)-壳聚糖-CTAB 上的吸附，腐殖酸也导致 Fe(III)-壳聚糖-CTAB 对 As(V)的吸附略有下降。两种吸附剂可将初始浓度不超过 5mg/L 的水中超过 94%的 As(V)去除。确定 1%（w/v）NaOH 溶液为最适宜的解吸剂。Fe(III)-壳聚糖和 Fe(III)-壳聚糖-CTAB 在五次吸附-解吸循环后仍保持其初始吸附容量。基于不同的表征结果，静电吸引和表面络合机制都在 Fe(III)-壳聚糖和 Fe(III)-壳聚糖-CTAB 上对 As(V)的吸附中发挥了重要作用。
