Ultrasound-assisted synthesis of biodiesel in the presence of a novel catalyst recovered from waste effluent/water: A mini-review

Abstract

The government of India has mainly focused on waste management, environment protection acts, and control of energy demand, which will lead to the development of a clean and green India. Nowadays most of the drinking water is getting polluted due to the harmful gases released by well-renowned industries mining operations, alloy industries, and dye industries. The presence of more amounts of heavy metals in drinking water leads to a rise in chemical levels than the constrained level in the environment, inside a human body, and any living being. Protection of the environment through the recovery of heavy metals from waste effluents through a chemical activation process using bio-derived activated carbons as adsorbents is one of the known strategies in the current decade that can be adopted. The application of these heavy metals as catalysts in the synthesis of biodiesel from nonedible oils through an ultrasound (US)-assisted process is one of the emerging strategies that will help in the reduction of energy demand. In the current review, the recovery of heavy metals from the waste effluents through a conventional chemical activation process and their applications as catalysts in the US-assisted synthesis of biodiesel from nonedible oils is discussed.