Newcastle University is working with engineering consultancy Royal HaskoningDHV to deliver a collaborative research project to better understand and reduce nitrous oxide (N₂O) emissions from wastewater treatment plants that use trickling filter systems. 

This project will use the BE:WISe Wastewater research pilot facility that Newcastle University developed with Northumbrian Water to deliver demonstration scale experiments in order to understand the emissions and potential mitigations from these processes.

This innovative research aims to provide crucial data that will help the UK water industry meet its greenhouse gas (GHG) reduction targets in line with the route to Net Zero 2030.

According to the UK water services regulation authority, Ofwat, 25% of the UK’s wastewater is treated at plants that use a trickling filter (TF) system, and it’s almost impossible to quantify emissions accurately at full-scale sites. This means there’s very little data on N₂O emission factors, and even less is known about sources and reduction of this powerful GHG.

To address this issue, Newcastle University and Royal HaskoningDHV, along with Northumbrian Water, has brought together a team of leading experts from Cranfield University, Mott MacDonald, Jacobs, and Farmiloe Fisher, to launch the "BEWISe about Trickling Filter Process Emissions" project.  Funding has been provided by 7 of the UK water companies (Northumbrian Water, Scottish Water, United Utilities, Yorkshire Water, Southern Water, Dwr Cymru and Anglian Water) as well as the National Biofilms Research Centre (NBIC).

The trials will take place at the BEWISe (Biological Engineering: Wastewater Innovation at Scale) wastewater treatment research facility at Birtley – a collaboration between Northumbrian Water and Newcastle University and is the largest wastewater treatment facility of its type in Europe. The plant has two TF units which can run in parallel to mimic “control” and “test” reactors. These will be retrofitted with stone media to better reflect UK applications.

The project will modify an existing Trickling Filter demonstration plant at the BEWISe centre to be able to accurately measure N₂O and other key parameters over 12 months of operation. This groundbreaking study will quantify N₂O emission factors in relation to basic process variables (such as nitrogen loading, temperature, and wetting rate) against a control and so inform future strategy to reduce emissions.

By conducting these controlled trials within an existing facility, the project will increase accuracy, reduce costs, and accelerate knowledge and value from the data. This project aims to inform investment decisions to optimise existing treatment works within the next investment period (AMP8) in order to work towards Net Zero by 2030

Professor Russell Davenport, Principal Investigator for BEWISe and Professor of Engineering for the Environment and Human Health, Newcastle University, said: “This is an exciting project that helps to improve our understanding of greenhouse gas emissions from the water industry and how we can reduce them. It is only possible because of the unique facilities that BEWISe offers and the excellent collaborative effort between academia and industry. We hope that this will be one of many impactful research projects that can be undertaken at BEWISe in the future.”