College of Chemical Engineering and Machinery, Eastern Liaoning University, Dandong, 118001, People's Republic of China.
Center for Molecular Science and Engineering, College of Science, Northeastern University, Shenyang, 110819, People's Republic of China.
Environ Sci Pollut Res Int. 2023 Sep;30(42):96554-96561. doi: 10.1007/s11356-023-29253-7. Epub 2023 Aug 14.
In this study, we have utilized corn bract, a green agricultural by-product, as a carrier. It is subsequently modified with zinc sulfide to synthesize an efficient composite material termed as corn bract/polydopamine@zinc sulfide (CB/PDA@ZnS). This novel composite demonstrates significant potential for biomass removal of mercury ions (Hg(II)). The composition, structure, and morphology of CB/PDA@ZnS composites are characterized by Fourier transform infrared (FT-IR) spectrum, thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and scanning electron microscope (SEM). The effect of pH value, adsorbent dosage, initial Hg(II) concentration, adsorption time and temperature, and coexistence ions on the adsorption behavior is investigated. The results show that CB/PDA@ZnS can efficiently remove Hg(II) from water with uptake capacities of 333.03 mg/g and removal efficiency of 99.91% under an optimal conditions (pH of 3, the adsorbent dosage of 0.015 g, contact time of 90 min, and initial concentration of 100 mg/L) at room temperature. The fitting analysis of the experimental data reveals that the adsorption process of Hg(II) follows the quasi-secondary adsorption kinetic model as well as the Langmuir isothermal adsorption model, which is a spontaneous heat absorption process. In addition, the composite adsorbent obtained exhibit excellent selectivity for Hg(II) ions and anti-coexisting ion interference performance. After five cycles of adsorption-desorption experiments, the corresponding adsorption capacity is 331.11 mg/g, accounting for 93.33% of the first adsorption capacity, indicating that the adsorbent has excellent regeneration performance. The stability of the adsorbent and the adsorption mechanism of Hg(II) ion are systematically discussed using FT-IR, XRD, and X-ray photoelectron spectroscopy (XPS). Finally, this adsorbent is tested for the removal of industrial wastewater containing Hg(II), and the adsorption and removal efficiency are 331.67 mg/g and 99.50%, respectively. This study provides a very valuable information for future Hg(II) removal from aqueous solutions.
在本研究中，我们利用玉米苞叶这一绿色农业副产物作为载体，通过与硫化锌进行修饰，合成了一种高效的复合材料，称为玉米苞叶/聚多巴胺@硫化锌（CB/PDA@ZnS）。该新型复合材料在去除汞离子（Hg(II)）方面具有显著的潜力。通过傅里叶变换红外光谱（FT-IR）谱、热重分析（TGA）、X 射线粉末衍射（XRD）和扫描电子显微镜（SEM）对 CB/PDA@ZnS 复合材料的组成、结构和形态进行了表征。研究了 pH 值、吸附剂用量、初始 Hg(II)浓度、吸附时间和温度以及共存离子对吸附行为的影响。结果表明，在最优条件（pH 值为 3，吸附剂用量为 0.015 g，接触时间为 90 min，初始浓度为 100 mg/L）下，CB/PDA@ZnS 可以从水中高效去除 Hg(II)，在室温下的最大吸附容量为 333.03 mg/g，去除效率为 99.91%。实验数据的拟合分析表明，Hg(II)的吸附过程符合准二级吸附动力学模型和 Langmuir 等温吸附模型，是一个自发的吸热过程。此外，该复合吸附剂对 Hg(II)离子表现出优异的选择性和抗共存离子干扰性能。经过五次吸附-解吸实验循环，相应的吸附容量为 331.11 mg/g，占第一次吸附容量的 93.33%，表明该吸附剂具有优异的再生性能。通过傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）和 X 射线光电子能谱（XPS）系统地讨论了吸附剂的稳定性和 Hg(II)离子的吸附机理。最后，该吸附剂用于去除含 Hg(II)的工业废水，吸附去除效率分别为 331.67 mg/g 和 99.50%。本研究为未来从水溶液中去除 Hg(II)提供了非常有价值的信息。
