Steinfeld Felix, Kersten Antje, Schabel Samuel, Kerpen Jutta
Faculty of Engineering, Institute of Environmental and Process Engineering, RheinMain University of Applied Sciences, Wiesbaden, Germany.
Chair of Paper Technology and Mechanical Process Engineering, Technical University of Darmstadt, Darmstadt, Germany.
Water Res. 2025 Mar 1;271:123016. doi: 10.1016/j.watres.2024.123016. Epub 2024 Dec 20.
Although the paper industry processes polymeric materials and discharges large amounts of wastewater, no research on microplastics in the wastewater from paper mills has been published to date. This study is the first to investigate this issue. The wastewater treatment plants of twelve representatively selected German paper mills were investigated using an analysis protocol based on µ-Raman spectroscopy. The results show that treated process water from surface waters is negligible as a source of microplastics (MPs) ≥ 20 µm. The microplastics concentrations in untreated wastewater range from 10 to 10 (MPs ≥ 20 µm)/m. Sources of microplastics in wastewater include recovered paper, functional polymers, and coating colors, among others. The most frequently detected polymers are polyethylene and polystyrene. In four cases, moving bed biofilm reactors were identified as a source of microplastics. The microplastics concentration in treated wastewater ranges from 10 to 10 (MPs ≥ 20 µm)/m. Hence, the removal rate of the wastewater treatment plants exceeds 99 %. Mechanical treatment and the activated sludge process have the highest removal rates of all treatment stages. The loads emitted into surface waters range from 10 to 10 (MPs ≥ 20 µm)/h, comparable to municipal wastewater treatment plants with a population equivalent of over 10,000 inhabitants. Compared with other wastewater-related emissions (the total emissions of municipal wastewater treatment plants, or combined sewer overflow), the contribution of paper mills to microplastics in the aquatic environment is low. The results of the removal efficiency can be transferred to other branches of industry and municipal wastewater treatment plants.
尽管造纸工业加工聚合材料并排放大量废水，但迄今为止，尚未发表关于造纸厂废水中微塑料的研究。本研究首次对该问题进行调查。使用基于μ-拉曼光谱的分析方案，对德国12家具有代表性的造纸厂的废水处理厂进行了调查。结果表明，作为≥20μm微塑料（MPs）的来源，地表水的处理工艺用水可忽略不计。未处理废水中的微塑料浓度范围为10至10（MPs≥20μm）/立方米。废水中微塑料的来源包括回收纸、功能聚合物和涂料等。最常检测到的聚合物是聚乙烯和聚苯乙烯。在四个案例中，移动床生物膜反应器被确定为微塑料的一个来源。处理后废水中的微塑料浓度范围为10至10（MPs≥20μm）/立方米。因此，废水处理厂的去除率超过99%。机械处理和活性污泥工艺在所有处理阶段中去除率最高。排入地表水的负荷范围为10至10（MPs≥20μm）/小时，与人口当量超过10000居民的城市污水处理厂相当。与其他与废水相关的排放（城市污水处理厂的总排放或合流制下水道溢流）相比，造纸厂对水生环境中微塑料的贡献较低。去除效率的结果可推广到其他工业部门和城市污水处理厂。
