Comparative Study of Different Oxygen Demands and Dissolved Oxygen

Water is the most prestigious gift provide by God on Earth. Now a day�s cleanliness of water resources is the most challenging goal for the protection of environment. Monitoring of water quality is required to provide information about load of pollutants on water body. Shortage of water already exists in many regions of the world and it may be due to polluted water. This is the main factor responsible for distribution and population density of both animal and plants. In the present study, water sampling was performed from Bhakra dam reservoir at 31�2439 N, 76�260 E i. e. Gobind sagar reservoir and Sutlej River from twelve different sites between July to December 2016 to study the various physico-chemical properties in three different seasons (Pre-monsoon, monsoon and post-monsoon) by keeping distance ten kilometer between two sampling sites as non-point source. It was clear from the investigation that quality of Sutlej River water changes seasonally. As season changes from pre-monsoon to monsoon, increasing trend was obtained for BOD (biochemical oxygen demand), COD (chemical oxygen demand) and DO (dissolved oxygen). Further change from monsoon to post-monsoon season, BOD and COD shows decreasing trend. While DO shows further increasing trend in post-monsoon season also except B9 sampling site.