With microplastics (MPs) being continuously found in various environments, the pollution of water supply systems by MPs is receiving increasing attention. As the sediment in drinking water distribution systems (DWDSs), pipe scales act as the interface for complex reactions between bulk water and pipe surfaces. Consequently, the fate of MPs in pipe scales requires exploration, especially colloidal MPs. In this study, MPs were detected in different pipe scale layers, with concentrations of 0.32–3.10 items g^-1. Subsequently, the adsorption interaction mechanisms between pipe scales and colloidal polystyrene microplastics (PSMPs) were investigated through batch adsorption experiments. The findings indicated that pipe scales showed a potential adsorption capacity for PSMPs. The adsorption kinetics and isotherms results demonstrated that the PSMP adsorption process was physically dominant and complicated. van der Waals and electrostatic interactions, hydrogen bonding, and pore filling were the main adsorption mechanisms. These results verify that colloidal MPs can be adsorbed by pipe scales, demonstrating that pipe scales play an essential role in the fate of colloidal MPs in DWDSs and the quality and security of drinking water. The secondary release of MPs from pipe scales is also worthy of attention due to the environmental and health risks.

随着微塑料（MPs）在各种环境中的不断发现，MPs对供水系统的污染越来越受到关注。作为饮用水分配系统 (DWDS) 中的沉积物，管道水垢充当散装水和管道表面之间复杂反应的界面。因此，管垢中 MPs 的命运需要探索，尤其是胶体 MPs。本研究在不同管垢层中检测到 MPs，浓度为 0.32~3.10 项 g ^-1. 随后，通过批量吸附实验研究了管垢与胶体聚苯乙烯微塑料（PSMPs）之间的吸附相互作用机制。研究结果表明，管垢显示出对 PSMP 的潜在吸附能力。吸附动力学和等温线结果表明，PSMP吸附过程在物理上占主导地位且复杂。范德华力和静电相互作用、氢键和孔填充是主要的吸附机制。这些结果验证了胶体 MPs 可以被管垢吸附，表明管垢在 DWDS 中胶体 MPs 的命运以及饮用水的质量和安全中起着至关重要的作用。由于环境和健康风险，管垢二次释放 MPs 也值得关注。