AP Environmental Science - Waste Water

1. AP Environmental Science
Exam Review
Wastewater

2. Wastewater
 Infectious Agents = cholera and typhoid fever
 Any water that has been used by humans.
 Human sewage
 Water drained from showers, tubs, sinks, dishwashers, washing
machines
 Water from industrial processes
 Storm water runoff
 In the U.S. = Moved through sewage pipes to a sewage treatment
facility.
 In developing countries = dumped into nearest river or ocean.

3. Municipal Sewage Treatment Plants
 Physical Treatment – removes debris
 Stones, sticks, rags, toys, objects flushed down toilets
 Debris is separated and sent to a landfill
 Primary Treatment – remaining water is passed into a settling
tank
 Suspended solids settle out as sludge
 Chemically treated polymers may be added to help
 Removes about 60% of the suspended solids and 30% of the
organic waste that requires oxygen in order to decompose

4. Municipal Sewage Treatment Plants, ctd
 Secondary Treatment – the biological treatment of wastewater in order to
continue to remove biodegradable waste; 97% suspended solids, 96% organic
waste; 70% toxic metals, organic chemicals, and phosphates; 50% of nitrogen;
and 5% dissolved salts have been removed.
 Trickling filters – aerobic bacteria digest waste as it seeps over bacteria-covered rock
beds
 Sludge processor – a tank filled with aerobic bacteria
 Solids are left out to settle
 Sludge – solids left after treatment
 Combined with solids from primary treatment, is burned, deposited in a landfill, or
dumped in the ocean
 Sludge burned = contains methane, which can be used to provide the electrical
power to run the waste facility
 Gray Water – (after secondary trtmnt) water is chlorinated to remove any living
cells, then discharged into a stream, the ocean or water that’s used to water
lawns.

5. Tertiary Treatment
 Involves passing the secondary treated water through a
series of sand and carbon filters, then more chlorination.
 San Jose Creek Plant (LA Cty, CA) – tertiary treated water from
the reclamation plants is discharged into percolation basins.
 Tertiary Treatment is expensive, but in arid or semi-arid regions
any gallon of water that can be reclaimed is needed.

6. Private Wasterwater Treatment
 Septic Tanks – act in a way that is similar to the primary and
secondary treatments at municipal plants.
 Water is discharged into leachate fields.
 To have a septic system – soil must be able to percolate the
water
 Some clay soils are not porous enough to allow percolation =
unsuitable for a sanitation field

7.  Which of the following choices gives the correct order of processing
sanitary waste in a sewage treatment plant?
A. Disinfection – breakdown of organics by bacteria – solid separation
B. Solid separation – breakdown of organics by bacteria – disinfection
C. Solid separation – disinfection – breakdown of organics by bacteria
D. Breakdown of organics by bacteria – solid separation - disinfection
E. Breakdown of organics by bacteria – disinfection – solid separation

8.  The presence of which of the following contaminants would be
the strongest reason for judging municipal sewage sludge unfit
for use as fertilizer?
A. Human feces
B. Ammonia
C. Phosphates
D. Nitrates
E. Heavy metals

9.  The dangers of disposing of toxic chemicals underground came to
public attention in which of the following locations?
A. Bhopal, India
B. Chernobyl, Ukraine
C. Love Canal, New York
D. Minamata, Japan
E. Three Mile Island, Pennsylvania

10. Backpack
Transported into factories
Provides job Mined sometimes
and away as zippers.
Greenhouse opportunities under hazardous
Larger Carbon
gas emission conditions.
Footprint.
Transportation
Nitrous
oxide
Aluminum
nylon
Nylon
coal
water
Nonrenewable
resource
Dangerous Polyester Used for school
supplies and or
working work
conditions in
coal mines
Less greenhouse
Made of
gas emission than synthesized fibers
Nylon.
Outer backpack material
Nylon