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Pasco: Day 2 Water Quality. Background Information: Temperature. Temperature arises from the random microscopic motions of the atomic and subatomic constituents of matter because of their kinetic energy.
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Pasco: Day 2 Water Quality
Background Information: Temperature • Temperature arises from the random microscopic motions of the atomic and subatomic constituents of matter because of their kinetic energy. • Since nearly all aquatic organisms are “cold-blooded”, the temperature of the water regulates their metabolism and ability to survive and reproduce effectively. • Temperature affects the ability of water to hold dissolved oxygen. • The temperature of the water regulates the specie composition and activity of aquatic life in any location. • Although aquatic ecosystems can become acclimated to slow, natural changes in water temperature, rapid unnatural changes, such as those caused by industrial thermal pollution or large cool water releases from dams, can be lethal for them, even in the temperature range that organisms can tolerate under natural conditions. • Natural influence on water temp: ambient air temperature, evaporation, solar radiation, water depth, flow rate and the amount of mixing in the water column. • Man-made influences: clear-cutting to the water’s edge, release of heat from industrial applications, and release of cold-impounded water into streams. • Temperature affects the amount of chlorination required to sanitize water for drinking purposes.
Background Information: pH • The pH test measures the concentration of hydrogen ions in water, assessing how acidic or basic the solution is. • Each decrement in pH unit represents a 10-fold increase in acidity. • pH is an important component of water quality, affecting the solubility of metals and other substances including nutrients. • Photosynthesis increases the pH of water. • Acidifying influences, those that lower the pH, include respiration by plants, animals, and bacteria, acid rain resulting from the burning of fossil fuels and runoff from mines, chemical plants, and other non-natural sources. • The ability to resist change in pH is called buffering capacity.
Background Info: Dissolved Oxygen • Dissolved oxygen is simply oxygen gas that is dissolved in water. • Temperature is an important factor regarding the amount of DO that water can hold-the lower the temperature of liquid water, the more DO it can hold. • The higher the air pressure (barometric pressure) the more DO can be held by liquid water. • Very high levels of DO can cause pipe corrosion, adding unwanted iron or other metals to the water, causing a deterioration in taste and clarity. • Low levels of DO can cause leaching of iron and manganese from sediments, which can affects the taste and color of water, in addition to staining plumbing fixtures or other materials the water comes in contact with. • Wind causes an increase in the dissolved oxygen levels of water.
Background Information: Conductivity • Conductivity is the measure of water’s ability to conduct electricity, depending on the concentration of dissolved ions in the water. • Measuring conductivity is a quick and easy way to estimate the amount of total dissolved solids in natural waters, since most of these solids dissolve to form ions. • Conductivity measurements can also be a useful tool for monitoring the inflow of saline water in estuaries and identifying sources of pollution, such as mining or industrial waste or agricultural runoff. • A high conductivity determination may indicate the need to conduct more specific analysis of specific ions to determine whether water contains high levels of an ion that would make it unsuitable for a designated use. • Temperature affects conductivity; each increase of 1 degree C causes an increase of about 2% in the conductivity. (therefore temperature should be controlled or accounted for)
