Tag: biology

Biological Oxygen Demand is a measurement of the amount of dissolved oxygen that is used by aerobic microorganisms when decomposing organic matter in water.  It is expressed in milligrams of oxygen consumed per liter of the sample during 5 days of incubation at 20°C and is used to determine the degree of organic pollution of water. Hence when a huge amount of carbon dioxide is added BOD will not be affected. Thus, the correct answer is option C.

BOD or biochemical oxygen demand is the amount of dissolved oxygen which is required by the aerobic organisms during the decomposition of organic matter. The BOD is measured at a specific temperature and specific period of time. BOD value is represented in the form of oxygen which is consumed per litre of the sample used for testing. The sample is tested before and after 5 days of incubation at 20 °C. The value describes the amount of organic material present in the contaminated or waste water. 

BOD or Biochemical oxygen demand is the amount of dissolved oxygen which is required by the aerobic organisms during the decomposition of organic matter. The BOD is measured at a specific temperature and specific period of time. BOD value is represented in the form of oxygen which is consumed per litre of the sample used for testing. The sample is tested before and after 5 days of incubation at 20 °C. The value describes the amount of organic material present in the contaminated or waste water. 

Water pollution can be identified by testing its PH level and Biological Oxygen Demand (BOD)  Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds. Acid rains, dumping of chemicals into the water by individuals, industries, and communities.; steam from coal mine drainage etc affect the pH of the water in its reservoir. Thus by testing the pH of water, on the scale from 1 to 14, the pollution in water can be identified.  Biochemical oxygen demand is a measure of the quantity of oxygen used by microorganisms (e.g., aerobic bacteria)  in the oxidation of organic matter. This value varies with the amount of pollution in water hence pollution can be determined by BOD.

Sewage is waste water having food residue, animal and human excreta, detergent, discharges from industrial and commercial establishments. Degree of impurity of water due to organic matter is measured in terms of BOD or biochemical oxygen demand. BOD is the oxygen in milligrams required for 5 days in one litre of water at 20 degree centigrade for the micro organisms to metabolise organic wastes. If the water, is polluted with sewage and other organic wastes, the BOD will increase.

Biochemical Oxygen Demand (BOD) is the oxygen in milligrams required  for 5 days in one litre of water at 20 degree centigrade for the micro organisms to metabolise organic wastes present in water.

Decomposition of organic matter by microbes requires oxygen. Degree of impurity of water due to organic matter is measured in terms of Biochemical oxygen demand or (BOD).