Main Article Content

Dr Shivani S Dhage
Dr D V Prabhu
Dr Prakash S Kelkar


BOD, kinetics of biodegradation, thermodynamic aspects of BOD,


Marine pollution occurs due to the entry of organized or unorganized, point or non – point land based releases of industrial, agricultural and residential waste. Biodegradable organic waste rich in microorganisms lead to potentially harmful effects and alter oxygen cycle, where as excessive inputs of nutrients like nitrogen and phosphorus stimulate algal growth leading to eutrophication.

Thermodynamics play an important role in chemicals reactions occurring in ocean during degradation of organic waste. The rate of reactions is altered due to temperature and high salinities. This aspect is very crucial while predicting the self purification capacity of the water body. Adequate experimental work pertaining to the order of reaction and thermodynamic constants is essential to prove the basis of the predicted assimilative capacity of the system.

In Mumbai, huge quantity of domestic waste is generated. Due to land restrictions, complete treatment of tertiary level is not feasible. The Municipal administrators take the advantage of coastal location and discharge this waste into the ocean with just meagre preliminary treatment. The disposal practices are advanced and well planned but still expected purification or dilution is not achieved in the near shore region. This has resulted in spoiling the impact zone of coastal areas creating stress on the living biota and non compliance of the marine water quality standards.

Three major issues in coastal system, viz. Operation and control of waste discharges, degradation patterns of pollutants and  self purification capacity needs systematic  evaluation to  maintain favorable conditions for aquatic life. Hence it is essential to study the reaction kinetics and thermodynamic behaviour of the biodegradation of carbonaceous waste occurring under highly saline conditions. Experiments are conducted to confirm the kinetics and thermodynamics of biodegradation of domestic waste water into marine water at variable salinities. The paper presents the findings of kinetic behaviour particularly the values for rate of reaction, Activation energy and related constants.

Abstract 174 | PDF Downloads 72


1. OSPAR convention for the protection of marine environment of the North-East Atlantic. Meeting of working group on priority substances (SPS [2] 01/4), ARONA (SECRETARIAT/EC): 15-19 October 2001

2. N. Clair, Sawyer, Perry L. MacCarthy, and Gene F. Parkin, ‘Chemistry for Environmental Engineers’, MacGraw Hill, Inc., 1994.

3. G.L. Eichhorn and I. M. Trachtenberg, J. Am. Chem.Soc., 76, (1954), 5185.

4. B. Loganathan, V. Ramadhas and V. K. Venugopalan, New Dilution Technique for BOD Estimation in Brackish and Sea Waters, Indian Journal of Marine Sciences, 14, September 1985, 156-159.

5. Standard Methods for the examination of Water and Wastewater, APHA, WPCF, AWWA, 21st Ed. 2005.

6. CPCB document on 3 day 27 degree test Validity of BOD determination at Higher Temperature as against Standard Condition of 200 C for 5 Days, Laboratory Analytical Techniques Series LAT S/4/87-88, Central Pollution Control Board, New Delhi, India.