Turning the Tide with Wastewater: Nature Based Solutions for a Thirstier World

Water scarcity is forcing governments and industries to rethink how we manage one of our most overlooked resources: wastewater. Today, more than 80% of the world’s wastewater is still released untreated, a loss of both water and valuable nutrients that could be recovered instead.

Wastewater treatment has typically relied on energy‑intensive, centralised plants, with multiple mechanical and chemical stages. While highly effective, this infrastructure is expensive to build and power, and it often stops short of reclaiming water for reuse.

In recent years, a new generation of approaches based on nature and biotechnology has emerged.

From wetlands that filter water through living ecosystems to microbial reactors that turn organics into electricity, these approaches point toward a future where wastewater becomes a resource rather than a liability.

Letting nature do the work

Constructed wetlands are currently the most established nature based solution for wastewater. These engineered systems mimic natural wetland functions, using a combination of wetland plants, substrates (such as gravel or soil) and associated microbial communities to remove contaminants. As wastewater flows slowly through the wetland, sedimentation, filtration, plant uptake and microbial degradation progressively purify the water.

A growing body of evidence suggests that well designed constructed wetlands can reliably treat domestic and industrial effluents to standards suitable for water reuse, particularly for agriculture and industry. In addition, they also require less energy, and integrate better into the landscape than a traditional water treatment plant. 

New regulations on river pollution and biodiversity, coupled with climate and net zero targets, are driving utilities and industrial players to incorporate wetlands in their treatment trains. In some cases, existing treatment ponds have been converted into hybrid lagoon–wetland systems, where plants and microorganisms finish the “polishing” of effluent before release or reuse. 

Microalgae, macro-impact

We have previously written about the many benefits of utilising algae. Industrial Phycology applies similar biological potential to wastewater treatment. Their technology builds on decades of research showing just how efficiently microalgae can strip out nutrients such as nitrogen and phosphorus from municipal and industrial effluents.

Inside Industrial Phycology’s reactors, dense algal communities are continuously fed by wastewater streams. As the algae bloom, they pull nutrients from the water, locking them into biomass while simultaneously releasing oxygen that fuels microbial breakdown of organic matter. The result is a compact, self sustaining treatment step that reduces eutrophication risk downstream and captures carbon in the process.

Once harvested, the nutrient rich biomass becomes a resource: it can be processed into fertilisers or soil enhancers, thereby effectively returning urban waste nutrients back to agricultural systems. It’s a tight loop: pollution removed, carbon captured, and valuable materials recovered, all in one elegant biological cycle.

Seaweed solutions

While microalgae operate primarily in controlled reactors, seaweed can deliver a similar nutrient scavenging function at a far larger, landscape scale.  

Algapelago, a UK based regenerative mariculture company, is developing seaweed systems that act both as productive farms and as living coastal infrastructure. Their approach offers a double benefit. As the seaweed grows, it naturally draws in dissolved nitrogen, phosphorus and carbon from the surrounding water. This helps to curb nutrient pollution from land based sources such as agriculture and aquaculture. In effect, each farm becomes a biological filter woven into the coastline, improving water quality while steadily producing harvestable biomass.

Algapelago can also process the harvested seaweed into low-carbon animal feed supplements and plant fertilisers. That gives the harvested biomass a further use, with nutrients taken up at sea finding their way back into sustainable agriculture.

Wastewater into watts

Cambrian Innovation’s system goes a step beyond conventional microbial treatment. Inside their EcoVolt® reactors, specialised bacteria consume the remaining organic pollutants and release electrons, which the system captures and redirects to support biogas production. This process boosts natural anaerobic digestion, making the treatment more stable, which improves the quality of the biogas.

The resulting biogas is fed into a combined heat‑and‑power unit, where it is converted into electricity. This produces anywhere from 30 to 400 kilowatts, depending on the site. By the time the water leaves the reactor, 80 to 90% of pollutants have been removed, making it suitable for uses such as irrigation or equipment washing. For some industries, the carbon savings are significant: a winery, for example, can cut roughly a kilogram of CO₂ per case of wine by generating its own clean energy. 

Microbes at work

Aquacycl also brings a distinct twist to wastewater treatment with its bioelectrochemical BETT® systems. These are modular microbial fuel cells that can be dropped directly onsite as a plug and play solution for high strength industrial waste streams. Instead of relying on large, centralised plants, BETT units use naturally occurring, locally sourced bacteria immobilised within the fuel cells to break down organic pollutants at their source.

As these microbes work, the system delivers three key advantages – it cuts sludge volumes, reduces primary sludge by as much as 80%, and eases the burden on downstream treatment. Unlike anaerobic systems that produce methane, BETT units also directly generate electricity from the organics they consume, thus lowering the overall carbon footprint of treatment.

By shrinking the physical and energy footprint of industrial wastewater management, Aquacycl aims to make decentralised water reuse a practical option for sectors ranging from food and beverage to consumer goods manufacturing, giving companies a cleaner, more efficient way to manage their hardest to treat waste streams.

Designing with nature for a drier future

In summary, water scarcity is, at root, a design problem. It is the result of infrastructure and systems built on the assumption of abundant, cheap freshwater and limitless sinks for pollution. Nature based solutions for wastewater treatment and reuse provide a different design philosophy, one that works with biological and ecological processes instead of against them.

Constructed wetlands that mimic natural filtration, microalgae reactors that harvest nutrients, seaweed farms that clean coastal waters, and microbial fuel cells that turn organics into electricity all point in the same direction: a future where wastewater is recognised as a valuable material stream.

As companies like Industrial Phycology, Algapelago, Cambrian Innovation and Aquacycl demonstrate, many of the most promising ideas sit at the interface between engineering and ecology. Protecting those ideas, and the data and know how that support them, will be a crucial part of scaling solutions that can help society adapt to a hotter, drier, more resource constrained world.

Nathan Zhang, Associate and Patent Attorney at Mewburn Ellis, comments:

“The common theme running through these technologies is the move from waste management to resource recovery. It’s not simply removing pollutants, but also recovering nutrients, harnessing energy, and creating valuable downstream products. That shift may fundamentally change how wastewater infrastructure, from reactor configurations to treatment processes, is designed. Protecting these innovations will help innovators capture the value of this transition.”