31 Aug 2022

Emerging trends in water: The need for action on N2O

In this Insight, Binnies Tony Koodie, Process Director, explores the challenges facing water companies as they strive to reduce emissions.

Studies have shown that the direct nitrous oxide (N2O) emissions created by biological activity in wastewater treatment plants (WwTP) can contribute as much as 86% of a plant’s operational carbon footprint. Despite this high number, N2O has received relatively little professional or academic focus until recently. To achieve net zero and meet regulator ambition to reduce operational greenhouse gas emissions, the water sector needs to work to close this gap.

N2O has a very high global warming potential: up to 273 times more than CO2 over a 100-year timescale. It can, on average, stay in the atmosphere for over 100 years. N2O also contributes to ozone depletion, which is another serious global warming challenge that can cause increased risk of cancer, among other things.

An example of the research gap that exists is that, at present, the carbon accounting workbook used as the industry standard has an emissions factor for N2O of 0.5% total nitrogen load to treatment. However, studies have revealed that nitrous oxide production varies significantly over time and across different WwTP sites. As an example, research shows that N2O emission factors for processes treating low-strength wastewater streams range between 0.003 and 5.6% of the N-load. The use of a single emissions factor means that there is a significant risk present of over- or underestimation of N2O impacts in carbon accounting by WwTPs.

Overall, the main solution at present is better monitoring and modelling of N2O in WwTPs so that more data can be accumulated and more targeted mitigation strategies crafted. Recent advances in instrumentation have enabled water companies to measure N2O emissions relatively easily and cheaply. One of the most widely adopted instruments utilises measurement of N2O in the liquid phase, enabling an accurate estimation of off-gas emissions. Some case studies show that as much as a 40% reduction in N2O emissions from activated sludge process (ASP) plants can be achieved by optimising measurable parameters. There is a variety of models and artificial intelligence applications that, combined with advances in measurement, could be powerful tools to detect and deliver reductions in N2O emissions.

At Binnies, we are helping our clients create a line of sight between strategic decision-making and the data necessary to make those decisions, leveraging the value of data-driven decisions at every point of the asset life cycle.

Advanced biokinetic models can be utilised to provide 3D screening of nitrogen and carbon conversions (effluent quality), process efficiency (mixing and aeration) and N2O emissions to enable specific solutions to be developed for water companies.

Contact us to find out more about how we can support you in cutting nitrous oxide emissions.

About Binnies

At Binnies, we create new possibilities for humanity through our innovative approach to delivery. Backed by a culture that has stayed true since the company’s founding over 100 years ago, Binnies develops intelligent water and environmental solutions using a whole-life-cycle approach to deliver functional infrastructure and lasting environmental and social legacies. We strive to elevate the quality of life for our local communities today and for generations to come.

Binnies is an RSK group company and was formerly part of Black & Veatch.

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About the RSK group (RSK)

RSK is a leading integrated environmental, engineering and technical services group made up of over 100 businesses. The group is headquartered in the United Kingdom and has an established presence in more than 40 countries around the world.

For over 30 years, RSK has been helping organisations realise their business goals efficiently, cost-effectively and with the minimum environmental and social impact. We deliver practical solutions to some of the greatest challenges of our time. As a client-focused business, our services are constantly evolving to directly respond to or pre-empt global conditions and legislative drivers.

Visit www.rskgroup.com and connect with us on LinkedInTwitter and Facebook as we continue to forge a stronger future together.

Media contacts 

Binnies UK  

Angela Collins Tel: +44 (0)1737 856399 | Mobile: +44 (0)7391 639733 | Email:collinsa@binnies.com