Modified Winkler Method for Dissolved Oxygen
Modified Winkler Method for Dissolved Oxygen Determination
Tiffany T. Lee
Department of Biological Sciences, College of Science
University of Santo Tomas, Manila, Philippines 1008
Date of Submission: February 17, 2011
Abstract
In this experiment, the Winkler Method was used to measure the dissolved oxygen (d.o.) in a water sample from the pond in the Arch of the Centuries which had the owl statues. Then, the amount of oxygen is determined through a series of reaction. Usually, Winkler bottles or dissolved oxygen bottles are used in this method; but in this laboratory analysis, 50mL syringes were used instead. The significance of a Winkler Method is that it can be used to determine the health or cleanliness of a lake or stream, to know the amount and type of biomass a freshwater system can support, and to measure the amount of decomposition occurring in the lake or stream. Also, if there is sufficient dissolved oxygen, a body of water can sustain life; but if there is depletion in dissolved oxygen, this may cause major shifts in the kinds of aquatic organisms found in water bodies.
Introduction The amount of dissolved oxygen present in water or wastewater is crucial for most forms of life. Dissolved oxygen is a good indicator of water quality. Oxygen dissolves into water by means of the atmosphere and plants. The primary source of oxygen for a body of water is from microscopic algae or submerged plants. The concentration of oxygen is greatest during the daylight hours due to photosynthesis.
Also, Dissolved Oxygen is affected by temperature. As the temperature of the water goes up, the lower the concentration of dissolved oxygen gas. Simply stated, the water temperature helps determine the maximum amount of oxygen gas that water can dissolve. This dissolved oxygen concentration, in return, helps determine water 's ability to support oxygen consuming creatures. Cooling a system down by 10 degrees slows down the rates of such reactions by a
Tiffany T. Lee
Department of Biological Sciences, College of Science
University of Santo Tomas, Manila, Philippines 1008
Date of Submission: February 17, 2011
Abstract
In this experiment, the Winkler Method was used to measure the dissolved oxygen (d.o.) in a water sample from the pond in the Arch of the Centuries which had the owl statues. Then, the amount of oxygen is determined through a series of reaction. Usually, Winkler bottles or dissolved oxygen bottles are used in this method; but in this laboratory analysis, 50mL syringes were used instead. The significance of a Winkler Method is that it can be used to determine the health or cleanliness of a lake or stream, to know the amount and type of biomass a freshwater system can support, and to measure the amount of decomposition occurring in the lake or stream. Also, if there is sufficient dissolved oxygen, a body of water can sustain life; but if there is depletion in dissolved oxygen, this may cause major shifts in the kinds of aquatic organisms found in water bodies.
Introduction The amount of dissolved oxygen present in water or wastewater is crucial for most forms of life. Dissolved oxygen is a good indicator of water quality. Oxygen dissolves into water by means of the atmosphere and plants. The primary source of oxygen for a body of water is from microscopic algae or submerged plants. The concentration of oxygen is greatest during the daylight hours due to photosynthesis.
Also, Dissolved Oxygen is affected by temperature. As the temperature of the water goes up, the lower the concentration of dissolved oxygen gas. Simply stated, the water temperature helps determine the maximum amount of oxygen gas that water can dissolve. This dissolved oxygen concentration, in return, helps determine water 's ability to support oxygen consuming creatures. Cooling a system down by 10 degrees slows down the rates of such reactions by a
References: 1. Kroner, R. C., Longbottom, J. E., Gorman, R.A., "A Comparison of Various Reagents Proposed for Use in the Winkler Procedure for Dissolved Oxygen", PHS Water Pollution Surveillance System Applications and Development, Report #12, Water Quality Section, Basic Data Branch, (July 1964). 2. Annual Book of ASTM Standards, Part 31, "Water", Standard D1589-60, Method A, p 373 (1976). 3. Standard Methods for the Examination of Water and Wastewater, 14th Edition, p 443, method 422 B (1975).