What is SALT, India's first mobile 'liquid tree' to fight pollution?

India's first mobile Smart Algal Liquid Tree (SALT) is an air-purification system developed by CSIR-CIMFR for crowded urban areas where planting trees is difficult. It uses microalgae in a water-filled tank to absorb carbon dioxide and release oxygen through photosynthesis. The mobile system can run on solar power or electricity, even after sunset with artificial light. It is designed to improve air quality in space-constrained locations.