Zhang Hai-Yan, Zhang Cai-Yun, Rao Wan-Li, Zhang Hong, Liang Guo-Hai, Deng Xin, Zhao Jian-Liang, Guan Yu-Feng, Ying Guang-Guo
SCNU Environmental Research Institute, Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment, South China Normal University, Guangzhou 510006, China; School of Environment, South China Normal University, Guangzhou 510006, China.
School of Environment, South China Normal University, Guangzhou 510006, China.
J Hazard Mater. 2022 Jul 15;434:128895. doi: 10.1016/j.jhazmat.2022.128895. Epub 2022 Apr 11.
Microplastics (MPs) are ubiquitous in aquatic environments, which are important carriers of emerging contaminants (ECs). Biofilms can be attached to the surface of MPs in a natural aquatic environment, which may influence chemical adsorption; however, knowledge of its impact is still limited. This study investigated the effect of biofilms on MPs on the adsorption of ECs through field-laboratory exposure experiments. Three types of MPs were naturally colonized with biofilms in lake. Then, biofilm-absent/biofilm-attached MPs were exposed to nine EC solutions at a concentration of 8 μg/L of each compound in laboratory. Most compounds exhibited 3.8 times lower concentrations on biofilm-attached MPs than on biofilm-absent MPs; only a few compounds showed enhanced adsorption. Pseudo-equilibrium was achieved within 72 h based on adsorption kinetics, implying fast adsorption of ECs on biofilm-attached MPs. The partition coefficients (K) for biofilm-attached MPs were 0.14 (diclofenac) to 535 (miconazole) L/kg and were positively correlated with octanol/water partition coefficients (K). This indicated that chemical properties (such as K) of the compounds determined their final adsorption amounts on MPs, although these were influenced by the presence of the biofilm. Hence, multiple influencing factors should be considered when evaluating the carrier potential of MPs for ECs in aquatic environments.
微塑料（MPs）在水生环境中无处不在，是新兴污染物（ECs）的重要载体。在天然水生环境中，生物膜可附着在微塑料表面，这可能会影响化学吸附；然而，其影响的相关知识仍然有限。本研究通过现场-实验室暴露实验，研究了生物膜对微塑料吸附新兴污染物的影响。三种类型的微塑料在湖泊中自然形成生物膜。然后，在实验室中将无生物膜/有生物膜附着的微塑料暴露于九种浓度均为8μg/L的新兴污染物溶液中。大多数化合物在有生物膜附着的微塑料上的浓度比在无生物膜的微塑料上低3.8倍；只有少数化合物显示出吸附增强。基于吸附动力学，在72小时内达到了准平衡，这意味着新兴污染物在有生物膜附着的微塑料上吸附迅速。有生物膜附着的微塑料的分配系数（K）为0.14（双氯芬酸）至535（咪康唑）L/kg，与正辛醇/水分配系数（K）呈正相关。这表明化合物的化学性质（如K）决定了它们在微塑料上的最终吸附量，尽管这些会受到生物膜存在的影响。因此，在评估微塑料在水生环境中作为新兴污染物载体的潜力时，应考虑多种影响因素。
