Chemical Engineering, HCT-Ruwais Woman's College, Ruwais, Abu Dhabi, United Arab Emirates.
Department of Engineering, University of Technology and Applied Sciences, Suhar, Sultanate of Oman.
Water Environ Res. 2022 Nov;94(11):e10809. doi: 10.1002/wer.10809.
Heavy metals and microplastics are two types of general contaminants that can cause significant damage to water systems and organisms. However, the interaction of heavy metal ions with microplastic in aquatic systems received less attention compared with that of organic contaminants. This study aims to explore the interaction of copper (II) ions with microplastic (polyethylene) in aquatic systems. The adsorption experiments were performed by varying several operational parameters including equilibrium pH, initial Cu (II) concentrations, and contact times. The microplastic was characterized using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared. The results confirmed the porous nature of the microplastic surface and the existence of various binding sites. The maximum Cu (II) uptake by microplastic was recorded as 1.23 mg/g at pH 5, according to the Langmuir adsorption isotherm. The experimental isotherm data exhibited a good fit to the Toth model, followed by the Langmuir and Freundlich equations, according to the correlation coefficient and %error values. The pseudo-first kinetics equation showed a better fit to copper (II) kinetics data compared with the pseudo-second kinetics equation. Elution of copper (II) ions from copper (II)-loaded microplastic was attempted using several elutants, and the results indicated that 0.01 M HNO performed well with elution efficiency over 99.5%. Thus, the elution experiments furnished proof that Cu-loaded microplastic may leach Cu (II) ions under rich acidic conditions, thereby aiding the transport of Cu (II) ions into the digestive tracts of aquatic organisms. PRACTITIONER POINTS: Polyethylene microplastics showed potential to sorb copper ions. The mechanism was electrostatic interaction between microplastics and metal ions. Maximum copper adsorption by microplastic was recorded as 1.23 mg/g. Once desorbed, Cu(II) transferred into the digestive tracts of aquatic organisms.
重金属和微塑料是两种常见的污染物，它们会对水系统和生物造成严重的损害。然而，与有机污染物相比，重金属离子与水系统中微塑料的相互作用受到的关注较少。本研究旨在探索铜（II）离子与水系统中微塑料（聚乙烯）的相互作用。通过改变几个操作参数（包括平衡 pH 值、初始 Cu（II）浓度和接触时间）进行吸附实验。通过 X 射线衍射、扫描电子显微镜和傅里叶变换红外光谱对微塑料进行了表征。结果证实了微塑料表面的多孔性质和各种结合位点的存在。根据 Langmuir 吸附等温线，在 pH 值为 5 时，微塑料对 Cu（II）的最大吸附量为 1.23mg/g。实验等温线数据根据相关系数和%误差值，与 Toth 模型拟合较好，其次是 Langmuir 和 Freundlich 方程。与伪二级动力学方程相比，伪一级动力学方程更适合铜（II）动力学数据。尝试使用几种洗脱剂从负载 Cu（II）的微塑料中洗脱 Cu（II）离子，结果表明 0.01 M HNO 洗脱效率超过 99.5%，效果较好。因此，洗脱实验证明负载 Cu 的微塑料可能会在富酸性条件下浸出 Cu（II）离子，从而帮助 Cu（II）离子进入水生生物的消化道。
聚乙烯微塑料具有吸附铜离子的潜力。
机制是微塑料和金属离子之间的静电相互作用。
微塑料对铜的最大吸附量为 1.23mg/g。
一旦解吸，Cu（II）就会转移到水生生物的消化道中。
