Researchers at the CSIR-Central Institute of Mining and Fuel Research (CIMFR) have developed India's first mobile Smart Algal Liquid Tree (SALT), a compact air-purification system that uses microalgae to absorb carbon dioxide and release oxygen. The device is designed for polluted urban areas where planting conventional trees is impractical.
How the Liquid Tree Works
Unlike a real tree, the SALT device houses microalgae in water inside an enclosed unit. Through photosynthesis, the algae continuously absorb CO2 from the surrounding air and release oxygen, improving air quality. The system also helps reduce dust and can operate round the clock using natural or artificial light. It is fitted with sensors that display air quality, carbon dioxide levels, temperature, humidity, and particulate matter.
Deployment and Feedback
The patented technology has been installed at the CSIR-CIMFR campus in Dhanbad and at Northern Coalfields Limited (NCL) in Singrauli, Madhya Pradesh, where it has received encouraging feedback, according to Vetrivel Anguselvi, senior principal scientist at CIMFR who led the project.
“The primary purpose of this innovation is to combat poor air quality in densely populated and space-constrained urban areas where there is little or no room to plant large trees,” Anguselvi said.
Additional Features
Designed to run on solar as well as electricity, the mobile unit also doubles as a public utility by providing shaded seating for four to eight people and charging points for mobile phones and laptops. Unlike conventional trees, the enclosed algae-based system does not require soil, is less affected by urban pollution and pests, and requires minimal maintenance.
Future Commercial Production
Anguselvi said the technology is intended for use in industrial areas as well as public places such as schools, airports, railway stations, bus terminals, shopping malls, parks, and theatres. CIMFR officials said discussions are underway for commercial production of the device, with efforts being made to price it affordably so that it can also be used in homes and localities facing severe air pollution.



