Beyond sewage: transforming waste into renewable energy

A pioneering project spearheaded by Glasgow Caledonian University aims to tackle the age-old problem of wastewater treatment head-on, potentially revolutionising the way we deal with residues.

The wastewater treatment industry is energy intensive, posing challenges in terms of both cost and sustainability. The Glasgow Caledonian research team, led by Dr Ania Escudero and supported by the Energy Technology Partnership (ETP) Studentship, is determined to change this narrative.

The team's 39-month study focuses on extracting value from the waste generated during wastewater treatment processes, specifically targeting activated sludge biomass. By employing cutting-edge low-temperature processing methods, the researchers aim to unlock the hidden potential within this waste stream.

In simple terms, one way to make good use of this waste material is by turning it into a dense form of carbon using a process that doesn't require very high temperatures. This carbon-rich substance, called hydrochar, can be used to produce energy more efficiently. By doing this, water companies can save on energy and create a sustainable way to generate power from waste.

Using low-temperature processes like this has several advantages:

• It reduces the amount of leftover waste, as well as the need for transporting and processing it, especially in remote areas.
• It allows for the extraction of renewable energy from sewage sludge, either by capturing heat or by making biofuels.
• It offers an alternative to spreading biosolids on land for disposal.
• It helps to recover valuable materials from the waste.
• It lowers carbon footprint, which is good for the environment.
• It decreases the likelihood of harmful substances being released into the environment.

The implications are far-reaching. If successful, the project could pave the way for a circular economy model, where resources are reused and recycled, minimising waste and environmental impact. This could lead to reduced energy consumption and increased energy security for water companies, benefitting communities across the UK.

Dr Escudero said: “The water industry is an energy intensive business driven by increasingly stringent quality, reliability, economic and sustainability requirements. It is the fourth most energy intensive sector in the UK, and it provides an essential service to the UK population. Therefore, achieving energy self-sufficiency and ensuring the energy security in the long run is becoming essential for the water companies.

“By harnessing the power of waste, the research promises tangible benefits for everyday people. From reducing carbon footprints to generating renewable energy, the project holds the potential to transform not only waste treatment but also our approach to sustainability.”

This studentship, funded by ETP, and co-funded by Scottish Water and Glasgow Caledonian, is based on a synergistic collaboration with additional support from the University of Strathclyde and the Hydro Nation Chair Research and Innovation programme (HNC).