N. Ranjan, Kanchan Kumari & R. C. Sinha*
Centre for Environment & Nature Conservation
Deptt. of Zoology, Patna University, Patna – 800005
Received 11th December, 2010; Revised 15th February, 2011
ABSTRACT : This study aims at the evaluation of bacterial quality of the rivers in North Bihar namely Burhi Gandak, Daha and Shikharana which originates from the Himalayas and are snow fed rivers. The water in Daha and Shikharana rivers reduce considerably during the summer seasons. One of the most important factors of water pollution is the microbial contamination especially with pathogenic microorganisms. The use of indicator bacteria such as total coliforms and fecal coliforms for the assessment of fecal pollution and related water quality deterioration is widely used to determine the microbial pollution and these have been included in water quality standards in different parts of the world. Water samples were collected at 8 sampling points monthly for a two year period. The study revealed that the coliforms were relatively higher (more than 5000 MPN/100 ml and sometimes even more than 16000 MPN/100 ml as against the prescribed bathing norms of 500 MPN/100 ml. The study revealed that all the 3 rivers under study are organically polluted due to discharge of sugar and distillery units. The coliforms showed a strong chemotactic response towards the sugar and distillery effluents resulting in high count of TC and FC. Through evolution, microorganism have developed effective mechanisms that help to regulate their cellular functions particularly during high COD and BOD because the carbon source of the organic pollutant serves as a good substrate for oxidation.