College of Urban Construction, Nanjing Tech University, Puzhu Road 30, Nanjing, 211816, PR China.
College of Urban Construction, Nanjing Tech University, Puzhu Road 30, Nanjing, 211816, PR China.
J Environ Manage. 2022 Jan 1;301:113793. doi: 10.1016/j.jenvman.2021.113793. Epub 2021 Oct 1.
Municipal wastewater treatment plants (WWTPs) have been regarded as the main receptors of microplastics in industrial and domestic wastewater. The excess sludge they generate is an important carrier for the microplastics to enter the environment. In China, relevant regional studies are still in an initial phase. In this work, microplastics in the sewage sludges at different sampling points of five WWTPs in Nanjing City (an important city in the Yangtze River basin) were investigated, including their abundance, morphology and chemical composition. Furthermore, the influence factors such as population density, economic development level, wastewater source and treatment process were also discussed. The analysis results through optical microscope and FT-IR showed that the detected microplastics were divided into fragments, films, fibers and granules. Their chemical component reached up to 19 species, including small amounts of petroleum resins which was scarcely detected in other studies. Wastewater source was the primary factor influencing the microplastic abundance and size in sludge. And the microplastic shape and chemical components were closely related to the industrial type. Furthermore, because the removal effect on the microplastics with different morphologies were varied with the treatment process, the preliminary suggestions on the technology for particular wastewater were proposed. This study provides partial regional data and analysis for the microplastics contained in the sludge of WWTPs, expecting to provide a certain theoretical support for the operations management of WWTPs and standardized sludge treatment.
城市污水处理厂（WWTPs）被认为是工业和生活废水中微塑料的主要受体。它们产生的剩余污泥是微塑料进入环境的重要载体。在中国，相关的区域性研究仍处于起步阶段。本研究调查了南京市（长江流域的重要城市）五个 WWTP 不同采样点的污水污泥中的微塑料，包括其丰度、形态和化学组成。此外，还讨论了人口密度、经济发展水平、废水来源和处理工艺等影响因素。通过光学显微镜和傅里叶变换红外光谱（FT-IR）的分析结果表明，检测到的微塑料分为碎片、薄膜、纤维和颗粒。它们的化学成分达到 19 种，包括在其他研究中很少检测到的少量石油树脂。废水来源是影响污泥中微塑料丰度和粒径的主要因素。微塑料的形状和化学成分与工业类型密切相关。此外，由于不同形态的微塑料的去除效果随处理工艺的不同而有所不同，因此对特定废水的技术提出了初步建议。本研究为 WWTP 污泥中的微塑料提供了部分区域性数据和分析，期望为 WWTP 的运行管理和标准化污泥处理提供一定的理论支持。
