Microplastics in sewage sludges.

Microplastics enter the sewage sludge via waste water. Recycling as fertiliser leads to the entry of microplastics in soils. This study provides an overview of the microplastic load of sewage sludge and their temporal variability. The starting point is an initial survey in 2020 at 35 wastewater treatment plants in Austria. For this purpose, 20 plants were repeatedly sampled and analysed in 2021/22 sewage sludge. The origin of polyurethane, the dominant plastic of the first survey, was also investigated. The composition of the plastics was consistent. Temporal deviations of the microplastic concentrations coincided with the type of canal system, an urban or rural character of the catchment area and the inhabitants:inside values of the installations. High polyurethane loads are presumably due to industrial inductors, but also entries from households are significant.微塑料通过废水进入污水污泥（sewage sludge）。将污水污泥用作肥料进行资源化利用时，会导致微塑料进入土壤环境。本研究系统综述了污水污泥中的微塑料负荷及其时间变异性。本研究以2020年对奥地利35座污水处理厂（wastewater treatment plants）开展的首次调查为起始基础。为此，研究团队于2021至2022年间对其中20座污水处理厂的污水污泥进行了重复采样与分析。本研究还对首次调查中占主导地位的塑料——聚氨酯（polyurethane）的来源展开了溯源探究。所检出塑料的组分占比保持一致。微塑料浓度的时间波动与管网系统类型、汇水区的城乡属性以及污水处理厂的服务人口规模均存在显著相关性。高聚氨酯负荷推测主要源于工业排放，但生活源输入的贡献同样不容忽视。