80 percent of the world’s sewage is dumped untreated into the natural environment. This is a huge health and environmental crisis, but traditional sewage treatment plants are costly and energy intensive, making them difficult to implement in many regions. The sewage contamination issue is particularly severe in Bangalore, India. Fortunately, local resident Tharun Kumar has come up with a solution.
Holy Cow, inspiration!
Traditional sewer plants use oxygen-fed bacteria to clean sewer water, but these require motors to provide the oxygen, driving up their cost and ecological footprint. Kumar’s design on the other hand is inspired by cow stomachs and cleans water without the need for a power source.
He and his team from ECOSTP Technologies designed a model that replicates the cow’s digestive system. Cow stomachs have four chambers that use bacteria that do not require oxygen to digest food. This food is separated out into nutrients, gas, water, and waste. The team created a sewer system with a four chamber system and uses bacteria collected from cow dung to clean wastewater in the very same way.
As gravity moves the sewage through the plant, the anaerobic system separates out solid waste. As it sinks, the rest of the waste is converted into gas and water and you end up with wastewater that is high enough in quality for greywater use in irrigation.
So far, ECOSTP Technologies has built 50 of these plants in India and is looking to expand to Africa. Although this technology will be most useful in regions with no formal water treatment infrastructure, it could also be valuable for established systems looking to reduce their energy consumption.