A Biogeochemical Framework for Understanding Biodegradation

About the Project

The environmental fate of synthetic polymers, including polyacrylates, polyquaterniums, and polyethylene glycols used in personal care and homecare products, remains poorly understood in natural aquatic systems. Recent European Chemicals Agency (ECHA) regulatory restrictions on polymer persistence highlight the urgent need for mechanistic understanding of biodegradation pathways. Current biodegradation assessments rely on standardised laboratory tests that may not reflect real-world environmental conditions, particularly the influence of nutrient availability on microbial degradation activity. This project addresses this knowledge gap by investigating polymer biodegradation within the context of nutrient biogeochemistry in freshwater systems.

Globally, significant volumes of untreated wastewater enter rivers and streams, creating natural gradients in nutrient availability and dissolved oxygen. These discharge zones provide ideal natural laboratories for investigating coupled nutrient-polymer dynamics. Using UK freshwater sites with documented wastewater inputs, we will characterise how nutrient conditions influence microbial communities and their capacity for polymer biodegradation. The project's primary objectives focus on testing whether nutrient availability – in particular the natural gradients created by untreated wastewater discharges - influence microbial activity associated with polymer biodegradation pathways. It will examine how elevated nutrient conditions, typical of these discharge zones, affect the breakdown of selected polymers such as those found in home and personal care products. The project will also quantify how seasonal and climate variations affect these coupled processes and develop predictive frameworks to determine how nutrient conditions found in untreated wastewater zones affect the likelihood and rate of polymer biodegradation.