UK recycling facility found to be releasing up to 1184 tons of microplastics annually, find researchers

09 May 2023 --- Plastic recycling facilities (PRF) could be a significant source of microplastic pollution in public water streams, according to a new study by researchers from the UK, Canada and New Zealand. The study authors say there is a significant lack of understanding of recycling facilities’ pollution potential.

The findings point toward an urgent need for improved filtration systems at PRFs and further research to establish the scale of potential threats to human and environmental health. 

“The current recycling process is a potential source of plastic pollution to the environment that it is designed to help prevent,” state the researchers. 

The study investigated microplastic pollution from a mixed PRF in the UK. Raw recycling wash water was analyzed using a fluorescence microscope. Filtration systems installed at the facility were found to remove the majority of microplastics >5µm, with high removal efficiencies for microplastics >40µm. 

However, microplastics <5µm were generally not removed by the filtration and subsequently discharged, with 59-1184 tons potentially being released into the environment annually. 

The microplastic pollution process through a plastic recycling facility.Due to the severity of the findings, the study authors recommend that additional filtration to remove the smaller microplastics before wash discharge is incorporated in wash water management.

“The release of microplastic pollution in wash water discharge from plastic recycling facilities is significantly understudied, and there is a research and knowledge gap in understanding how plastic recycling facilities may contribute to the environmental plastic pollution problem,” states the study. 

Plastic recycling, filtration inefficiency 
Since the COVID-19 pandemic, increased use of plastic has been accepted as necessary to preserve hygiene and prevent food waste, according to Innova Market Insights. As consumers accept this, there is also an increased demand for circularity, and the plastic industry is working toward higher recycling rates. 

These efforts have also been spurred by legislation, with minimum recycling and recyclability requirements coming into force through revisions to the Packaging and Packaging Waste Directive. 

However, PRFs use processes whereby plastics are separated by type, broken down and granulated, and then pelletized for re-processing. The use of mechanical friction, abrasion, or equivalent methods to break down the plastics within these processes can increase the microplastic concentration in wash water at the facilities, according to the research. 

The study authors highlight that currently, no legislation or standard exists within the UK – the country of study – to control the release of microplastics into the environment from controlled activities such as recycling. 

Future research 
Future studies of PRFs are “highly recommended” to provide a comprehensive understanding of microplastic creation and release due to PRF actions (both atmospherically and via water discharge) across multiple facilities globally, say the researchers.

To advance this assessment, size fractionation of samples is recommended before analysis is undertaken to ensure smaller particles are accurately represented in analysis and to prevent potential “hiding” and sample overloading.

The results are published in the Journal of Hazardous Materials Advances. 

By Louis Gore-Langton