Title: Effects of salinity and temperature on the rate of biodegradation of domestic waste released into the marine waters around Mumbai City, India

Biography:

D V Prabhu is an adjunct faculty and former Head of the Department of Chemistry, Wilson College (University of Mumbai) Mumbai. His research interests are reaction kinetics and environmental chemistry. He has published 50 papers in national and international journals and has 77 paper presentations in conferences in India and abroad. He has served as the Dean of Science Faculty of University of Mumbai and President of Indian Chemical Society (Mumbai Branch). He is the Editor in Chief of GP Globalize Research Journal of Chemistry (ISSN 2581 5911,www.gpglobalize.com) and Chief Editor of Green Chemistry and Technology Letters (e-ISSN 2455 3611). He has authored six ISBN books in physical and analytical chemistry. He has been honored with the best chemistry teacher award by Chemical Research Society of India in 2006 and the Association of Kineticists of India award by Indian Chemical Society in 2002. His paper was adjudged the best paper presented in the Environmental Chemistry section at the 6th International Congress of Chemistry and Environment (ICCE 2013) held at Antwerp, Belgium in July 2013. He is actively involved in the Indian National and International Chemistry and Junior Science Olympiads and has served as the delegation leader to the International Chemistry and Junior Science Olympiads. He is the founder general secretary of association of chemistry teachers, India’s national registered body of chemistry educators and Chairman, Bombay Association for Science Education (BASE).

Abstract

Marine pollution around cities is largely due to the discharge of untreated industrial and domestic wastes. Mumbai City generates a large amount of domestic waste water which is released largely untreated into the coastal waters. As a result, the marine environment is adversely affected and marine life gets depleted. The health of a water body is defined by physicochemical parameters like BOD, COD, DO, salinity and pH. Domestic waste water is rich in microorganisms which help in its biodegradation by a process of wet oxidation. In the presence of microorganisms, the carbonaceous organic matter in domestic waste gets oxidized:

Carbon in organic matter + O₂ --------à  CO₂ + H₂O + Biomass

The first order kinetics of biodegradation of domestic waste by wet oxidation has been studied with particular reference to the effects of 1) salinity in the range [Cl^-1] =0 to 20000 mg L^-1 and 2) temperature (20C, 27C) on the rate of biodegradation. An inverse relationship was observed between the rate of biodegradation and salinity .The relatively high temperatures in tropical regions significantly affect biodegradation rates. The chemical reactions occurring in the oceans during the degradation of organic wastes are governed by thermodynamic considerations hence the wet oxidation was studied at different temperatures and thermodynamic activation parameters of the reaction were evaluated and interpreted. The BOD values have been calculated at different salinities from the DO values determined at regular time intervals during the degradation process and correlated with the rate of biodegradation of domestic waste water. Dissolved Oxygen was determined by Alsteberg azide modification of the Winkler method. Similarly, the kinetics of degradation of a synthetic sample, Glucose- Glutamic acid was studied. The slow degradation of organic matter in environmental effluents like domestic waste should be critically considered while planning the disposal options for organic wastes in the marine ecosystem. Recommendations have been made to local municipal authorities to treat domestic waste before discharge into the coastal waters.