chemical and physical properties of water quality
DESCRIPTION
Envirothon 2009. Chemical and physical properties of water quality. pH. pH ranges from 0-14 0 is the most acidic 14 is the most basic/alkaline 7 is neutral Most healthy bodies of water in the U.S. are between 6.5 and 8.5. Certain macros exist in certain pH ranges. alkalinity. - PowerPoint PPT PresentationTRANSCRIPT
Chemical and physical properties of water quality
pH
• pH ranges from 0-14– 0 is the most acidic– 14 is the most basic/alkaline
• 7 is neutral– Most healthy bodies of water in the U.S. are
between 6.5 and 8.5.– Certain macros exist in certain pH ranges
alkalinity
• Alkalinity is a measure of how well water can neutralize acids that might get added– Should be between 20-200 mg/L– Less than 20 mg/L means the water cannot easily
buffer changes in pH– Acids can be added from acid rain and other
environmental pollutants– Determined by the geology (rocks) that the water
flows through.– Link to Wilkes alkalinity info
Dissolved oxygen
• D.O. is the amount of oxygen dissolved in a body of water– The more O2 that is dissolved, the more that is
available to living organisms– Changes with temperature– Cold water holds more O2 than warm water.
Stream velocity
• Determined by depth and width of stream– Narrow streams are often faster and colder– Wide streams are slower and warmer – Will have greater velocity if the stream is the
same depth all along its route– Certain macros are adapted to live in faster
streams while others must live in slow water.
Water temperature
• Affects the amount of dissolved oxygen– Cooler water holds more oxygen
• Affects rate of photosynthesis– Warmer water = faster photosynthesis
• Affects organisms’ sensitivity to pollutants– Warmer water = higher sensitivity
• Link to temp website
Turbidity
• Measure of how much suspended matter is in the water– Cloudy water has lots of silt, sand, clay and organic
material floating– Certain macros must live in clear water (clogs up
gills, for example)– Some macros are adapted to live in more turbid
water.– Comes from erosion, runoff, algae blooms and
sediment disturbances