Transcript Dihydrogen Monoxide - University of Cincinnati

Water Cycle Review
Global Distribution of Water
• Quantity and Quality
• Demonstration activity
Water Uses
• Domestic
• Agricultural
• Industrial
• Power generation (dams are not counted
as withdrawal)
No
stress
Low
Mid
High
stress stress stress
Very high
stress
No data available
Water stress indicator: Withdrawal to Availability ratio (2003)*
Water withdrawal = water used for irrigation, livestock, domestic and industrial purposes (2000)
Water availability = average annual water availability based on 1961-1990
USGS Trends in Water Use 1950-2000
Withdrawals
Total withdrawals increased steadily from 1950 to 1980, declined more than 9 percent from
1980 to 1985, and have varied less than 3 percent between the 5-year intervals since 1985.
Total withdrawals peaked during 1980, although total U.S. population has increased steadily
since 1950. Total withdrawals for 2000 were similar to the 1990 total withdrawals, although
population had increased 13 percent since 1990.
USGS Trends in Water Use 1950-2000
Uses
(U.S. Geological Survey, 1984; updated using 1995 estimates of water use)
http://water.usgs.gov/watuse/misc/consuse-renewable.html
Potential Effects of Global Warming*
• Results of increases in temperature
(More than one-sixth of the world’s population live in
glacier- or snowmelt-fed river basins)
• Sea level rise (saltwater intrusion?)
• Changes in precipitation
• Semi-arid and arid areas are particularly exposed to
the impacts of climate change on freshwater
• Higher water temperatures, increased precipitation
intensity, and longer periods of low flows exacerbate
many forms of water pollution, with impacts on
ecosystems, human health, water system reliability
and operating costs
* Freshwater resources and their management; Climate Change 2007: Impacts,
Adaptation and Vulnerability. Contribution of Working Group II to the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change (IPCC 2007 )
Figure TS.5. Illustrative map of future climate change impacts on freshwater which are a threat to the
sustainable development of the affected regions. Background shows ensemble mean change of annual
runoff, in percent, between the present (1981-2000) and 2081-2100 for the SRES A1B emissions
scenario; blue denotes increased runoff, red denotes decreased runoff. Underlying map from Nohara et
al. (2006) [F3.8].
Waterborne Illnesses
• What are some common waterborne
illnesses?
• How do we detect their likelihood?
• How can we prevent them?
Water Pollution
• Types of Pollutants
• Organic (living and nonliving)
• Inorganic
• Thermal
• Sources of Pollutants
• Point
• Nonpoint
• USEPA Water Pollution Control Regulations
Drinking Water Quality
• USEPA Drinking Water Regulations
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Coliform bacteria
Turbidity
Organic and inorganic chemicals
Radionuclides
Pesticides in Drinking Water
• How do they get there?
• What happens when we drink them?
• What happens if they react with the
most common disinfectant used for
drinking water in the US?
Sourcewater Protection
• Groundwater (Aquifer) recharge zones
• Surface water pollution
Cincinnati Drinking Water
Sources
• Two supplies:
• surface water from the Ohio River (88%)
• groundwater from ten wells in the Great
Miami Aquifer (12%)
• Slightly different treatment at each
plant
• Why?
Great Miami Buried Valley Aquifer
Magnified View of Sand and Gravel
Aquifer
Groundwater fills the open pockets
lying between individual sand and
gravel particles. The larger the
interconnected air spaces (i.e., the
greater the porosity) the more
rapidly groundwater will move
through the aquifer
Teays River
Destroyed by glaciers of Pleistocene Ice Age 2 million years ago
Cincinnati Water Balance
• Stormwater management
• Combined sewer overflows
PUR Demonstration
Common Treatment Steps
• Coagulation
• Filtration
• Disinfection
Other methods
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Activated carbon
Ion exchange/chemical precipitation
Membranes
Air stripping
(then comes distribution)
Greater Cincinnati Water Works
Major Treatment Processes:
•Settling (coagulation, flocculation)
•Filtration
•Disinfection