How an L&T project site in north-east India is generating drinking water from the atmosphere
What do the ancient Incas community, the Stenocara gr acilipes beetle and the L&T team constructing India’s longest river bridge project in north-east India have in common? All three perfected the art and science of generating water from the air!
The 19-km Dhubri-Phulbari Bridge project in Assam that L&T started constructing in 2021, will be the world’s longest extradosed cable- stayed bridge and India’s longest river bridge.
A problem that the project team initially faced was the scarcity of drinking water. In addition to water scarcity and contaminated ground water, it is often difficult to transport water as the project locations are inaccessible.
To address the pressing issue, the L&T team resorted to something innovative: they decided to try out an atmospheric water generator.
Accordingly, a demo atmospheric water generator, customised to L&T’s requirements, was procured and a pilot test was conducted at one of L&T offices in Mumbai. The water generated by the machine met every Indian Standard (IS) specification and was found suitable for drinking.
As the name suggests, the atmospheric water generator draws water vapour from the atmosphere. The air is filtered, and a condensation unit receives the humid airflow from the evaporator. The condensation unit then removes the heat from the humid airflow, which cools it down and converts it into water. This process is called atmospheric condensation.
The water is then purified through a four-step filtration process. Its power consumption depends upon the geographic location and the machine’s configuration.
Ticking the boxes of scalability, replicability and sustainability, the atmospheric water generator was deemed the best solution for the Dhubri-Phulbari Bridge project. Thus, a machine was procured for over Rs 9.13 lakh and installed at the project site.
L&T CEO & MD Mr S N Subrahmanyan inaugurated the water generator on 29 April this year and dedicated it to the workforce at the project. Generating 1,000 litres of water per day, the machine is now quenching the thirst of 100-odd people simply from thin air.
The machine has several salient features. It produces drinking water (with minerals) and can also be customised to meet specific needs. It lasts for 15 years and carries a 10- year warranty on components. If integrated with renewable power sources, a user can take carbon credits as well. Best of all, the water wastage is nil as compared to reverse osmosis, wherein around thrice the water produced is wasted.
Not only at project sites, but the atmospheric water generator can also be installed at residential and commercial premises facing water scarcity.
