Real time tracking & monitoring of microplastics in aquatic environments

Microplastics (MPs) are an emerging contaminant of increasing concern that are ubiquitous within freshwater and marine ecosystems.

Rivers are recognised as a fundamental transport pathway for MPs; connecting terrestrial plastic sources to marine ecosystems, as well as an area where high levels of biological activity and modification can occur. However, there is little consideration as to the sources and fate of plastics within these freshwater ecosystems.

Rivers are subject to plastic pollution from both point (i.e. sewage systems) and diffuse (i.e. agricultural and urban runoff) sources. It is expected that riverbed sediments act as a sink for microplastic debris (1).

However, the extent to which riverbeds interact with MPs and their entrapment rates will be governed by many physical, biological and chemical factors. Colonisation studies of plastic debris by microbial biofilms have shown to cause buoyant polymers to sink (2,3). Equally, microbial biofilms over riverbed sediment will influence MP infiltration and settling rates.

Nevertheless, the relative importance of these processes remains largely unclear with empirical data urgently needed to parametrise models. In this project you will investigate the interactions and feedbacks between riverbed dynamics and MPs.

The main aim will be to determine the key variables which contribute to the entrapment and resuspension of MPs within this freshwater ecotone.

Different types of plastic particles with different densities will be considered and analysed using novel state-of the-art technology and innovative methods.

The release rate and sources of MPs is vital for a more complete understanding and assessment of the hazards posed by these contaminants.

As such, the new insights offered by the project have the potential to contribute directly towards new policies relating to water management and environmental conservation.