Posted: 22 October 2020
A sewage treatment facility
Understanding the release and accumulation of microplastics in the environment is critical for understanding the potential effects these may have on ecosystems.
Dr Alice Horton, NOC researcher

Research published by the National Oceanography Centre (NOC) this week in Environmental Pollution shows that wastewater treatment processes remove 99.8% microplastics from the treated wastewater released to rivers, meaning that the majority do not enter rivers, and therefore do not reach the sea.

State-of-the-art methods were used to characterise and quantify microplastics in samples, with strict protocols to account for any contamination that may occur from the field or lab environment.

Scientists discovered that some treatment technologies seem better than others at removing microplastics, with activated sludge and tertiary treatment technologies appearing more effective at filtering out microplastics. The scientists discovered that sludge acts as a reservoir for these captured microplastics, where they can accumulate. This research helps us better understand the role of wastewater treatment works in handling microplastics throughout the treatment process.

NOC researcher, Dr Alice Horton, said “Understanding the release and accumulation of microplastics in the environment is critical for understanding the potential effects these may have on ecosystems. The methods used in this study allow detection and quantification of microplastics to a degree of accuracy not usually achieved in microplastics research. This is important step forward in our ability to confidently handle and analyse microplastics in complex environmental samples”.

The work was funded by UK Water Industry Research, led by UK CEH, with researchers from the NOC, Lancaster University and Aalborg University. The next stage of this research focuses on developing a mass-balance approach to better understand the fate of microplastics throughout the treatment process, relating to different treatment technologies.

This work builds on the NOC’s cutting-edge research into marine plastic contamination, which aims to better understand environmental exposure to plastics and the potential harms it can cause.