Cow’s digestive process inspires purification plant

Cow’s digestive process inspires purification plant

After six years of research, a Bengaluru startup has designed a zero-power, zero-chemicals sewage treatment technology that can help save our lakes

A Bengaluru startup has turned to the cow for lessons in wastewater purification, and hopes it can save our lakes from pollution.

ECOSTP Technologies has designed a zero-power, zero-chemical sewage treatment technology, which is modeled on the cow’s digestive system. The practice of mimicking biological processes is called biomimicry.

“Our technology has no moving parts as compared to a conventional sewage treatment plant (STP), which makes use of motors, exhaust fans, pumps, and blowers, and consumes energy. It is a replica of a cow’s stomach,” co-founder and CEO Tharun Kumar tells DH.

The team started installing this technology across the country in 2017 after six years of R&D. Tharun shares what inspired the innovation.

“There are over 12 million people living in Bengaluru. When they flush, 40 per cent of their waste reaches the city’s lakes and the lake burns. But why are people sending 40 per cent of what they flush into lakes? That’s because conventional motor-based STPs are a failure as they are complicated to run, they need lots of power and they require skilled operators,” he begins.

When an STP fails, the sewage falls into the drains and all drains lead to lakes. “In our country, sewer lines and storm water drains are interconnected, which add to the misery,” he points out.

The conventional STPs offer a three-step, aerobic bacteria-based treatment and that is highly power-intensive. ECOSTP, on the other hand, makes use of anaerobic bacteria, which is common in a septic tank and abundant in a cow’s stomach. “We decided to mimic that,” says Tharun on behalf of his team Lokesh Rajashekaraiah, Ramya Rajagopal, Amar Patel, and Pankaj Srivastava.

Anaerobic bacteria-based systems have existed in pockets but never achieved the success that his startup did. “Our strategy was to look at how a cow’s stomach implements anaerobic digestion in detail. The ruminant stomach in a cow turns grass into milk. We biologised the same method to convert ‘bad water’ into ‘good water’. We created a biomimetic wall structure mimicking bovine tripe,” he explains.

Simply put, their model breaks down the organic fecal content into treated water. “We add anaerobic bacteria catalyst seed (one time addition) from a cow dung substrate and sewage,” he gets into the details.

The treated water can be used to flush toilets and for gardening. “It can be used for drinking after additional treatment,” claims Tharun.

Users thrilled

Chaitra Saraf, founder of Zero Gravity Architects, turned to ECOSTP to design a 100 per cent eco-friendly resort in Chikkamagaluru. She says she is saving on power and bills and she hasn’t faced breakdowns. Similarly, Suhail Rahman, MD and CEO of CoEvolve, finds it low on maintenance and a good choice for sustainable waste management.

Wallet factor

ECOSTP’s installation kit ranges from Rs 5 to Rs 10 lakh, depending on the capacity. Civil work will need to be done by the client.

4-step purification

Phase 1: Hydrolysis — Bacterial action splits the long-chain organic compounds (proteins, fats, or carbohydrates) into simpler ones (such as amino acids, fatty acids, sugars).

Phase 2: Acidogenesis — The acidogenic bacteria breaks down these compounds into short-chain
fatty acids (such as acetic acid, propionic acid, butyric acid, valeric acid) and alcohol. These bacteria can function in a large pH range.

Phase 3: Acetogenesis — The acetogenic bacteria converts these organic acids and alcohol into acetic acid, hydrogen, and carbon dioxide.

Phase 4: Methanogenesis — Anaerobic bacteria belonging to the genus like Methanococcus, Methanobacterium, and Methanoscarcinagenera turn these products into methane and carbon dioxide.

Challenges and opportunities

Installing an ECOSTP plant in apartments was initially difficult because it takes double the space as compared to the conventional wastewater treatment facilities. So the team decided to construct the main sewage chambers underground, beneath the buildings and road, and put the final filter in a garden. “We have built 30 of these eco-friendly sewage plants in new housing developments in Bengaluru and over 100 across 17 states, and have plans for more. We also hope to export the idea to other countries,” says CEO Tharun Kumar. The team also plans to make a DIY kit so clients can build treatment plants using local material.

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