Published: 10 November 2022

Sustainability at Surrey: COP27 Solutions Day

With conventional sewage treatment methods causing high greenhouse gas emissions, environmental microbiologist Dr Bing Guo is focused on developing innovative alternatives using biotechnology. To mark COP27 Solutions Day, we caught up with her to learn more.

What are you researching?

We’re trying to find more sustainable ways of processing wastewater (sewage). Our aim is to develop new technologies which reduce harmful emissions and recover energy and nutrients – transforming organic pollutants into clean sources of energy such as biomethane.

The process of removing ammonia from wastewater creates nitrous oxide emissions which have around a 300 times higher greenhouse gas effect than CO2 emissions – so a key aim is to reduce nitrous oxide emissions. This is the focus of a new project with the Environmental Biotechnology Network. It’s a highly complex area because there are thousands of bacterial species involved in the wastewater treatment process and our task, using microbiology methods, is to pinpoint which bacteria produce nitrous oxide. With global water use, storage and distribution accounting for 10 per cent of global greenhouse gas emissions, this could have a big impact towards net zero.

What got you interested in this area of research?

Having studied for my undergraduate degree in environmental engineering I explored different research directions I could pursue. Environmental microbiology and biotechnology are complex systems but powerful ways to achieve low-cost low-energy and low-carbon biodegradation. This is what led to my interest in the way wastewater is processed by microorganisms.

Why is this work so important, and what impact could it have?

When the sewage treatment processes we use today were developed – 100 years ago – the goal was removing pollutants, not sustainability. Today, with the pace of climate change accelerating fast, we urgently need to reassess wastewater engineering methods.

At the same time, around the world, 70 per cent of wastewater is not treated properly which means it flows into and degrades the natural environment. This is even more harmful, not only in terms of CO2 emissions but also public health, because pathogens and antimicrobial resistance from sewage find their way into the drinking water cycle if wastewater is not treated correctly.

The hope is that as wastewater processing is introduced in developing countries we can ‘skip’ conventional methods which generate heavy emissions and install new, sustainable processes.

With news that the world is close to irreversible climate breakdown, what are your reasons for staying hopeful?

We all need to act to meet this challenge, and I feel that this is the part that the research community can play. No one sector can achieve the goal of net zero but through our work, and demonstrating more sustainable processes, we can make an impact on other sectors and the decisions that are made.


Find out more about our research in the Centre for Environmental Health and Engineering.

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