Constructed wetlands for the treatment of combined sewer overflow upstream of centralised wastewater treatment plants

This study presents the results obtained from a three-year monitoring campaign (from 2018 to 2020), which involved the constructed wetland system of Carimate WWTP, located in Como province (Italy). Experimental water quality data show good treatment performance, with average removal in the range of 123-198 tCOD/y, 1.5-2.5 tTP/y and 6.0-9.7 tTN/y for COD, total phosphorus, and total nitrogen, respectively. In recent years, moreover, there has been a growing concern among the scientific community regarding the presence of various microcontaminants, such as microplastics (MPs) and persistent organic pollutants (POPs), in water due to their potential impact on water bodies and related ecosystems. In this context, the present research also proposes a monitoring of the concentration levels of MPs and different classes of POPs and an evaluation of their removal efficiency by the CW system of Carimate.