Centre for Environmental and Marine Studies (CESAM) & Department of Chemistry, University of Aveiro, Aveiro, Portugal.
Department of Chemical Engineering, University of Granada, Granada, Spain.
Sci Total Environ. 2021 Jul 1;776:145999. doi: 10.1016/j.scitotenv.2021.145999. Epub 2021 Feb 20.
Sources contributing to specific concentration of microplastics and fibers are still not completely understood. This study aimed at assessing the concentrations of microplastics (2-5000 μm) and fibers (18-5667 μm) in three areas of distinct influences in the Douro river, Porto, Portugal: (i) a countryside area; (ii) a wastewater treatment effluent release zone; and (iii) an area in proximity to a boat dock and maintenance station. Nile Red staining coupled with microscopy allowed the identification of small microplastics (≥2 μm) with a median concentration of the three areas of 231 MP L. Most were fragments (69%). Sizes <40 μm were the most abundant (84%). Highest concentrations of microplastics were found near the boat dock/maintenance and lowest in the countryside area. Fibers were mostly natural (non-synthetic, 63%). Highest concentrations of fibers were found in the area influenced by the wastewater effluent, especially of synthetic fibers, and lowest in the countryside area. Concentration of all fibers and synthetic fibers was 46 F L and 6 F L, respectively. High concentrations of microplastics and fiber contamination suggest that the wastewater treatment plant effluent and boat dock/maintenance are the likely sources originating hotspot areas.
造成特定浓度微塑料和纤维的来源仍不完全清楚。本研究旨在评估葡萄牙波尔图杜罗河三个具有不同影响区域的微塑料（2-5000μm）和纤维（18-5667μm）的浓度：（i）农村地区；（ii）废水处理厂排放区；以及（iii）靠近船坞和维护站的区域。尼罗红染色结合显微镜可识别小粒径微塑料（≥2μm），三个区域的中值浓度为 231MPL。大多数为碎片（69%）。<40μm 的粒径最为丰富（84%）。船坞/维护区附近的微塑料浓度最高，农村地区最低。纤维主要为天然纤维（非合成纤维，63%）。受废水影响的区域纤维浓度最高，尤其是合成纤维，农村地区最低。所有纤维和合成纤维的浓度分别为 46FL 和 6FL。微塑料和纤维污染的高浓度表明，废水处理厂的污水和船坞/维护站可能是造成这些热点区域污染的来源。
