What if sewage treatment plants did more than just purify wastewater—what if they evolved into sustainable resource factories, actively enabling a future-proof circular economy and driving regional CO₂ reduction?
For over a century, sewage treatment works have primarily been sites where contaminated water is treated. Their core function has always been to prevent pollution of natural water bodies. However, considering overloaded infrastructure, resource scarcity, ambitious climate targets and evolving regulation, a new way of thinking is required: sewage treatment works can and should develop into centres for resource recovery and reuse.
A frequently overlooked component of municipal wastewater is cellulose, primarily derived from toilet paper, which holds significant untapped potential. This material can be recovered locally, recycled and reused. Recovering this secondary resource reduces treatment volumes, improves energy efficiency and contributes to decarbonisation.
A potential that grows alongside increasing sustainability awareness.
In the context of current developments, two approaches can be observed among decision-makers:
- Either waiting until regulatory pressure and operational constraints make change unavoidable,,
- Or using uncertainty as an opportunity to proactively develop processes and infrastructure in a structured and timely manner.
At Cirtec, we are convinced that cellulose recovery and utilisation is both economically viable and environmentally responsible:
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The technologies are already available and proven
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Positive operational experience exists
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Industrial end-markets are steadily growing
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The regulatory framework increasingly supports circular transformation
Why sewage treatment works need to be re-evaluated
Rethinking sewage treatment goes far beyond meeting technical compliance requirements. Treatment works must be embedded more strongly within a regional, circular and responsible framework, creating both environmental and economic value. The challenges are diverse and require urgent solutions.
Today’s challenges
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Overloaded systems: Many sewage treatment works are approaching or exceeding design capacity. Early-stage separation of cellulose can reduce loadings, easing pressure on assets while retaining sufficient organic matter for potential biogas production.
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Waste reduction: Extracting cellulose can reduce sludge volumes by approximately 10–20%.
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Energy efficiency: Aeration accounts for up to 60% of a treatment works’ energy consumption. Reducing organic solids content can therefore significantly lower energy demand.
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Limited space: Many facilities are situated in densely built environments, leaving little room for expansion. Compact solutions are therefore becoming increasingly important.
Future challenges
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Emissions and energy neutrality: Wastewater treatment works will not only need to remove pollutants but also actively contribute to national climate targets. In the UK context, this aligns with the Climate Change Act 2008 and legally binding carbon budgets, including the target of net zero greenhouse gas emissions by 2050. This requires optimised processes, resource recovery and intelligent energy management.
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Beneficial use of by-products: Phosphorus, nitrogen, heat and cellulose are increasingly seen as strategic resources rather than waste streams.
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New local applications: Recovered cellulose can be used in construction (e.g. asphalt), the chemical and materials industries, or agriculture (e.g. bio-based products and composites).
The role of UK regulatory and policy frameworks
The UK regulatory and policy landscape is increasingly aligned with resource efficiency, decarbonisation and circular economy principles:
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Urban Waste Water Treatment Regulations 1994 (as amended): These regulations implement the principles of the EU Urban Waste Water Treatment Directive in England and Wales, focusing on appropriate treatment and protection of receiving waters. While originally EU-derived, they remain part of retained UK law and continue to evolve through national amendments and enforcement by the Environment Agency.
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Environment Act 2021: Establishes long-term environmental governance in England, including targets on air quality, biodiversity, water quality and waste reduction, supporting more circular approaches to resource management.
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Climate Change Act 2008: Provides the legal framework for the UK’s carbon budgets and the commitment to achieve net zero emissions by 2050.
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Ofwat Price Review (PR24) and sector strategy direction: Encourages water companies in England and Wales to innovate, reduce operational carbon, improve resilience and consider nature-based and circular economy solutions.
More broadly, UK water policy is increasingly focused on reducing greenhouse gas emissions from wastewater treatment processes and improving resource efficiency across the sector.
Cirtec’s added value: Through cellulose recovery, wastewater operators can reduce operating costs, lower their carbon footprint and simultaneously prepare for tightening regulatory expectations.
Concrete benefits of cellulose recovery
Recovering cellulose from wastewater combines operational, environmental and societal advantages:
✅ Increased plant capacity: throughput can improve by 10–20%
✅ Reduced energy consumption: aeration demand decreases by 10-25%
✅ Lower sludge production: sludge volumes reduce by 10-20%
✅ Local value chains: integration into regional bio-based material supply chains
✅ Climate impact: approximately 2-2.5 tonnes of CO₂ savings per tonne of recovered cellulose
A circular vision for our regions
Cellulose recovery also contributes to more resilient, locally anchored economies.
For example:
In a region with 200,000 inhabitants, several hundred tonnes of toilet paper enter the wastewater stream annually. Through local recovery and recycling, this material flow can be transformed into a feedstock for public infrastructure projects within the same region.
In this way, valuable cellulose remains within the circular economy. Dependence on imported materials decreases, logistics costs are reduced, and municipalities benefit from increased local employment and industrial activity.
Conclusion
The sewage treatment works of the future will no longer function solely as purification facilities, but as sustainable resource recovery hubs.
This transition is already underway across parts of Europe and is increasingly reflected in UK policy direction. Regulation is pushing transformation, technologies are already available, and the resource base is present in existing wastewater streams.
For water utilities and operators, early adoption offers a dual advantage: reduced costs and lower carbon emissions, alongside the creation of local value. This is not a distant vision – it is already becoming reality.
Cirtec supports you as a trusted partner in this transition: from feasibility studies through to the implementation of proven solutions. Do not wait for sector change to overtake you – act now and explore the recovery potential of your treatment works. Contact our experts to learn more.
