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In Our Water- and Climate-Stressed World, There’s No Excuse for Wastewater Going to Waste

Globally, 80% of wastewater is discharged into local environments with minimal or no treatment — water that could be recycled and reused. California-based startup Aquacycl's waste-to-energy solution protects water resources while helping companies reduce costs.

Water is arguably the most important factor in human development. However, only 0.5 percent of the water on Earth is available to use as freshwater. And that’s a problem, given that a quarter of the world’s population is already living in water-stressed countries — a situation that is steadily getting worse. In the race to solve the climate crisis and ensure sustainable development goals are reached, we ignore water management at our peril.

Of course, governments have a big responsibility to integrate sustainable water-management solutions. And there appears to be plenty of commitment to the cause: According to UNFCCC, water has been named as the top climate-adaptation priority in 79 percent of the Nationally Determined Contributions that countries have submitted in response to the Paris Agreement.

But, as ever, nations will need big water-using companies to play their role in finding innovative solutions to reduce, reuse and recycle water wherever possible. Industrial companies have been reducing their water use ratio for decades, and water-related disclosure is increasing. CDP reports that 3,370 companies reported on their water impacts in 2021, up from just 176 in 2010.

But as companies reduce their water use, the concentration of wastewater — the water that has already been used, having gone through a factory facility, a home, a sanitation system, or rain falling on a roof, for example — increases. So, smarter management and processing of wastewater presents a significant opportunity. Globally, an estimated 80 percent of all wastewater is discharged into the local environment with minimal or no treatment — water that could be recycled and reused.

California-based startup Aquacycl believes it has come up with a solution to protect water resources while helping industrial firms reduce their costs.

“Some companies we have talked to are spending more than $2 million a year per site on wastewater surcharges,” Orianna Bretschger tells Sustainable Brands™. She is the company’s CEO and one of three co-founders — alongside CTO Sofia Babanova and Ryoji Naito, SVP of Manufacturing and Engineering.

The firm’s Bio-electrochemical Treatment Technology — known simply as BETT — uses natural bacteria to clean wastewater, reduce sludge and produce direct electricity. The bacteria, which the company sources on or near a customer’s site, breaks down organic matter in the wastewater. This releases electrons during the natural process of respiration; these are captured as a direct current in the BETT system and can be used to offset the power consumption of the system. By using higher electrical currents, the treatment can be sped up due to the enhanced microbial respiration. This means wastewater treatment can be done in hours, instead of the days or weeks required by most anaerobic processes.

“Microbial fuel cells have long been explored as a waste-to-energy approach that provide energy-neutral wastewater treatment, but technical challenges have limited the commercialization of the technology until now,” Bretschger says.

Addressing climate challenges, too

The technology — borne out of Bretschger and Babanova’s joint research at a leading genomics institute back in 2015 — not only improves the quality of the water that can be reused, it is also helping companies address their Scopes 1, 2 and 3 greenhouse gas (GHG) emissions. This is especially important given the water sector contributes roughly 4-5 percent of global GHG emissions.

According to Bretschger, centralized wastewater treatment relies heavily on aerobic systems — meaning that air is blown into the wastewater, which requires large amounts of energy and generates high volumes of sludge. The sludge is commonly landfilled, which breaks down into methane — the GHG 84 times more potent than CO2.

“When we remove the bulk of the organics at the industrial customers’ site, it means that the city doesn’t need to use as much energy for treatment and minimal sludge is produced from the streams associated with the discharge.”

The Aquacycl team have crunched the numbers: By treating high-strength wastewater onsite, BETT systems can mitigate 90 percent of GHG emissions that would otherwise be generated during aerobic treatment. For one of its customers, this has meant mitigating more than 100 tons of GHG emissions every month, Bretschger says.

To reduce overall demand for freshwater, the BETT system removes the bulk of organic material from the process wastewater, enabling water recycling with complementary technologies. For example, in Colorado, the team has installed a system at a distillery where the treated wastewater will be reused on an adjacent farm as high-nutrient agricultural water.

“We’re also reducing water demand by eliminating dilution of these ultra-concentrated flows,” Bretschger adds. “The typical water adage is, ‘the solution to pollution is dilution.’ But we’re changing this to only treating what needs to be treated.”

For companies to shift their operational models, the associated cost savings must be worthwhile. Here, by separating and treating small volumes of highly concentrated wastewater, the lower-concentrate streams can be reused or discharged to sewers without surcharges. By only treating a small volume, treatment costs can be kept to a minimum — with smaller equipment, fewer chemicals and less energy being used to operate.

‘An exercise in patience and perseverance’

Bretschger admits that proving a new technology in the water sector can be “an exercise in patience and perseverance.” Aquacycl has gone from a laboratory experiment in 2016 to securing its first commercial, multi-year pay-for-performance contract five years later. In that time, it has continued to validate the technology — working with the US Navy, breweries, confectioners and beverage manufacturers. And the startup has lent on a range of accelerator programs for support, not least Google for Startups — which provided the Aquacycl team with expert mentors to help navigate everything from machine learning to marketing and sales.

So, what’s next for the ambitious entrepreneurs? The next 12 months will see the firm expand from the US to Europe as part of Bretschger’s aim for “world domination.”

“We have droughts across Europe that we haven’t seen in 500 years. Heat waves in China are shutting down power plants. There are unprecedented floods in Pakistan covering a third of the country. We aren’t prepared for these massive changes that are happening,” she laments. “Right now, companies largely see wastewater as a problem; they want to stay in compliance at the lowest cost. We see it as an opportunity — because there is value in wastewater. Decentralized wastewater treatment is one element that can help us as we are forced to adapt to this new reality.”