How biotechnology is turning the tide on UK water systems battling climate change

The UK’s climate continues to change. In 2025, we experienced one of the driest spring seasons in more than 50 years, with just 128.2mm of rainfall, according to Met Office reports. While that may mean more time spent enjoying the outdoors, the extended dry spells are simultaneously placing significant pressure on our water system, highlighting an urgent need to reimagine how it is managed.

Historically, the UK’s water system has been largely linear, with water extracted, treated, used, and then disposed of, with less focus on recovering resources along the way. Typical wastewater treatment processes can be chemically intensive and energy hungry, and while they are essential for public health and environmental protection, there are a number of emerging approaches using natural, bio-based techniques that could see the entire industry transformed.

With greater emphasis on circularity within the water system – using biotechnology as part of the treatment process – wastewater can become an even more valuable resource, rather than being viewed as waste or a by-product. Not only can valuable materials and minerals be extracted from wastewater, but the resulting liquid can also be used as part of industrial processes, leaving fresh water supplies clear for human consumption, particularly during times of drought or scarcity.

Biotechnology, covering a broad range of tools, is central to this shift, and there are several examples of exciting innovations and collaborations demonstrating the potential of bio-based techniques to support the water treatment system. The question is not whether these changes are needed, but how quickly we can put them into practice.

Biochars – charcoal-like substances created when materials are burned at high temperatures and deprived of oxygen – are showing huge potential in different water-based applications. Carbogenics, for example, a spin-out company from the University of Edinburgh, produces biochar using organic waste such as difficult-to-recycle paper, which is then used for wastewater screening. It has also shown positive results in the reduction of harmful gases – such as ammonia, hydrogen sulphide, methane, and carbon dioxide – emitted from bodies of water used as part of the anaerobic digestion process.

We have also seen instances where bodies of water impacted by naturally occurring algal blooms are being treated using bio-based solutions. In a project funded by the Industrial Biotechnology Innovation Centre (IBioIC) and Scottish Water, a consortium of partners assessed the viability of a water filter created from biochar derived from sewage sludge.

Further developments led by Scottish Water’s research and innovation team include efforts to reduce the use of chemicals in water production. At present, producing drinking water and treating wastewater relies heavily on coagulants – chemicals such as aluminium or iron salts that force fine particles and impurities to clump together so they can be removed. However, these coagulants are only used once and then wasted, so finding ways to recover and reuse them – for example, using engineered bioreactors –can replace the need for newly manufactured chemicals and boost sustainability.

Scottish Water is also working with the Scottish Environmental Protection Agency (SEPA) to explore the potential for 25 different output materials to be turned into higher-value, more useful products, including phosphorus, cellulose, biogas, and biochar.

As is the case with any of these examples, progress depends on both collaboration and investment. Organisations including IBioIC, Scottish Water, SEPA and others all have a role to play in supporting the next generation of our water system and creating the right environment to nurture innovation. Ofwat, the industry’s regulator in England, recently announced a £400m commitment to support ambitious and collaborative water innovation projects over the next five years.

Policy is also critical, with the likes of the Scottish Government’s Hydro Nation strategy aiming to develop Scotland’s water resources for maximum economic benefit and build resilience against the threat of climate change.

Many water companies are still focused on the reduction of energy use, but it is time to look at the climate crisis from all angles. There are many untapped opportunities to explore as part of a more circular approach. But, due to the scale and diversity of the challenges, a transition will require a multidisciplinary approach to make innovation and research a reality.

As the climate crisis accelerates, biotechnology can become a key element in how we conserve water, demonstrating that liquid once deemed as ‘waste’ can, with the right science, become a resource to be reused.