College of Resources and Environment, Qingdao Agricultural University,Qingdao 266005, PR China.
College of Resources and Environment, Qingdao Agricultural University,Qingdao 266005, PR China.
Sci Total Environ. 2024 Jan 10;907:167857. doi: 10.1016/j.scitotenv.2023.167857. Epub 2023 Oct 20.
Although recent studies have been conducted on the pollution and toxicity of microplastics with heavy metals or antibiotics, it is necessary to further investigate the coexistence of antibiotics and heavy metals on the surface of microplastics. In this study, the mechanisms of As(III) adsorption by polystyrene (PS) and polyamide (PA) microplastics in the presence of antibiotics (ciprofloxacin, CIP) were investigated. Adsorption behavior was investigated using kinetic and isotherm models, and the effects of microplastic particle size, aging, ion concentration, pH, xanthic acid (FA), and tannic acid (TA) were considered. Adsorption kinetics and isotherm models showed that the kinetics of As(III) adsorption on PS were consistent with a pseudo-first-order model; the kinetics of adsorption on PA were more consistent with segmented linear regression. The Freundlich model is consistent with the adsorption isotherms of As(III) on PS and PA. The smaller the microplastic particle size and the longer the aging time, the better the adsorption of As(III). Increasing NOsignificantly inhibited the adsorption of As(III) by PS, while it first promoted and then inhibited the adsorption by PA. The effect of pH was similar to that ofNO. The adsorption of As(III) by PS was significantly promoted by FA and TA, regardless of the presence of CIP; the adsorption of As(III) by PA was inhibited. Scanning electron microscopy (SEM) was used to characterize microscopic morphology of pristine and aged PS and PA microplastics; Fourier transform infrared (FTIR) and X-ray absorption spectroscopy (XPS) revealed changes in surface functional groups of PS and PA, while demonstrating the importance of different functional groups in exogenous additives (CIP and dissolved organic matter, DOM) in the adsorption of As(III). This study provides new insight into adsorption behaviors and interaction mechanisms between ternary pollutants.
尽管最近已经对重金属或抗生素存在的微塑料的污染和毒性进行了研究，但有必要进一步研究抗生素和重金属在微塑料表面的共存。本研究考察了在抗生素（环丙沙星，CIP）存在下，聚苯乙烯（PS）和聚酰胺（PA）微塑料对砷（III）的吸附机制。通过动力学和等温线模型研究了吸附行为，并考虑了微塑料粒径、老化、离子浓度、pH 值、黄腐酸（FA）和单宁酸（TA）的影响。吸附动力学和等温线模型表明，PS 上砷（III）吸附的动力学符合准一级模型；吸附 PA 的动力学更符合分段线性回归。Freundlich 模型与 PS 和 PA 上砷（III）的吸附等温线一致。微塑料粒径越小、老化时间越长，砷（III）的吸附效果越好。NOsignificantly 显著抑制 PS 对 As(III)的吸附，而对 PA 的吸附则先促进后抑制。pH 值的影响与 NO 相似。FA 和 TA 均显著促进 PS 对 As(III)的吸附，而与 CIP 共存与否无关；PA 对 As(III)的吸附则受到抑制。扫描电子显微镜（SEM）用于表征原始和老化的 PS 和 PA 微塑料的微观形貌；傅里叶变换红外（FTIR）和 X 射线吸收光谱（XPS）揭示了 PS 和 PA 表面官能团的变化，同时证明了不同官能团在外源添加剂（CIP 和溶解有机物，DOM）在吸附砷（III）中的重要性。本研究为三元污染物的吸附行为和相互作用机制提供了新的见解。
