Title: Green alternatives of the future

Abstract

Solvents are essential part of various industries such as chemical, pharmaceutical, textile, paint and pigment etc. Water is one of the key elements in variety of industries where it is used as solvent, in cleaning, washing and cooling etc. processes. Major industrial hubs include chemical, pharmaceutical, fertilizers, textile, dye, sugar mills, tannery, pulp and paper, paint and many more industries. The solvent usage by industries is about 80-90% of total mass and they also account 80-85% waste it produces. Over 500 million of wastewater is dumped into rivers from these industrial plants. The two largest rivers emanating from the Himalayas, viz., Ganga and Yamuna in India which have been instrumental in establishing the civilizations and subsequent industrialization along its banks of river has also been badly affected by this . Both the rivers are heavily contaminated with human waste and industrial contaminants. These industrial effluents contain hazardous toxins, heavy metal particles like arsenic, mercury, dyes and it reduces the BOD (Biological Oxygen Demand) of water body indicating degradation of entire aquatic biota along with the humans which are dependable on these water resource. These industries are also responsible for air pollution as most of these industrial solvents are Volatile Organic Solvents (VOCs) with high volatility, toxicity and environmentally hazardous. In the recent decades, active research has been undertaken to find better, greener and sustainable resources, and methodologies. Use of several benign solvents viz., water, polyethylene glycol and supercritical fluids have been proposed, along with deep eutectic solvents (DESs) and ionic liquids (ILs), to minimize the effects of pollution in air quality caused from effects of volatile organic solvents. Various projects like Namami Gange and Ganga Action Parivar (GAP), Yamuna Action Plan (YAP) are established which are directly working on river surface cleaning, sewerage treatment, wastewater management, conservation of biodiversity and public outreach and awareness. In this context, an attempt will be made to understand how these benign solvents may prove to be viable alternatives to the carcinogenic solvents in various industrial applications for sustainable development.