India’s rapidly increasing population has made it tougher for the country to manage precious resources like water. New Delhi, the capital, is one of the worst affected cities. Absolute Water, a water recovery management firm in New Delhi, is helping recycle sewage water and make it available and affordable for citizens. The company’s “TOILET to TAP” project is a first step towards achieving this goal.
This one of a kind project utilises the process of vermi-filtration to convert sewage water into water suitable for potable and non-potable applications.
The company has signed an agreement with the Delhi Jal Board to set up such decentralised sewage treatment plants (STPs) in order to recover usable water from the wastewater generated from different avenues. The plant, located in Keshopur, has a capacity of 100 kilolitres per day and utilises sewage water to make pure drinking water.,
Additionally, the plant has a recovery rate of 85% and can be operated by semi-skilled labour.
Conventional STPs run on the principle of aeration, utilise chemicals and have a significantly high requirement of electricity. However, Absolute Water’s STP and water recovery system is a game-changer in the context of sustainable solutions. It utilises a bio-filter comprised of gravel, especially bred worms and bacteria.
These components act on the suspended and organic solids in the raw sewage water and biologically degrade it in an environmentally safe manner.
The recovered water is of potable quality (as per WHO standards) and can be used for drinking and bathing purposes. The reject from the membrane can also be used as liquid urea due to its richness in nitrogen. Maintenance costs are also low, with only the organic media of worms, sand and gravel requiring replacement at intervals of six to eight months. Each removed batch of media can be used as biofertiliser in agriculture. Every element of the STP is reusable, thus making it an environmentally sustainable, economically viable and socially acceptable technology.
This is a flowchart representing how the treatment plant works:
– Pranay Kejriwal
Featured image (right) credit: Flickr