MEASUREMENT & RELATIONSHIP OF PHYSICAL CHEMICAL PARAMETERS (Cont)
Dissolved Oxygen: Sources of DO in surface waters are primarily atmospheric reaeration and photosynthetic activity of aquatic plants. DO is an important factor in chemical reactions in water and in the survival of aquatic organisms. In surface water, DO concentration typically range from 2-10mg/l. Occasion of super saturation (greater than 100 percent DO saturation) often are related to excess photosynthetic production of oxygen by aquatic plants as a result of nutrient (nitrogen and Phosphorus) enrichment, sunlight and warm water temperature.
DO may be depleted in inorganic oxidation reaction or by biological and chemical processes that consume dissolved, suspended or precipitated organic matter.
. DO in water that have specific conductance values of greater than 2000 microsiemens/centimeter should be corrected for salinity.
The newest technology for measuring DO is the Luminescent sensor that is based on dynamic fluorescence quenching.