Abstract

This study investigates microplastic (MPs) dynamics of a recently established surface flow 2100 population equivalent polishing constructed wetland (CW) receiving 1.4 ML per day of secondary treated wastewater. MPs type, size ranges and concentrations were measured along the CW at a 2-months sampling campaign. The CW received an average of 5·10 6 MPs per day (6 MPs per liter), mostly 100–1000 μm-sized synthetic fibers followed by fragments in the same size range. 95 % of MPs were retained, resulting in 0.30 ± 0.09 MPs per liter in CW effluent. Most MPs (97 %) were trapped within the first 20 % of the CW which consisted of a settling pond and shallow vegetated treatment cells and provided an areal removal rate > 4000 MP m −2 d −1. Data and microscopic analysis indicate MPs erosion and fragmentation in the CW. Turbidity and suspended solids were no indicator for MP removal due to water fowl activity, algal growth, and preferential flow conditions. This is the first study on MP dynamics in an independently operating full scale free water surface CW incorporated into a municipal wastewater treatment scheme. Surface flow CWs can retain MPs effectively but accumulation in CW sediments and substrate needs to be considered when further utilized or recycled.

Original languageEnglish
Article number160113
JournalScience of the Total Environment
Volume858
Issue number3
Early online date14 Nov 2022
DOIs
Publication statusE-pub ahead of print - 14 Nov 2022

Keywords

  • Constructed wetland
  • Free water surface constructed wetland
  • Microplastics
  • Microplastics aggregation
  • Microplastics removal
  • Microplastics retention
  • Wastewater

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution

Cite this