review ch19 - AaronFreeman

forestsaintregisOil and Offshore

Nov 8, 2013 (3 years and 11 months ago)

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Water Pollution

G. Tyler Miller’s

Living in the Environment

13
th

Edition


Chapter 19





What is water pollution?

Any chemical, biological, or physical
change in water quality that has a
harmful

effect on living organisms
or makes water
unsuitable

for
desired uses.





Major categories of water
pollutants

1.
Infectious Agents

2.
Oxygen
-
Demanding Wastes

3.
Inorganic Chemicals

4.
Organic Chemicals

5.
Plant Nutrients

6.
Sediment

7.
Radioactive Material

8.
Heat (Thermal Pollution)

Review
Table 19.1!!





Common Diseases Transmitted Through
Contaminated Drinking Water

Type of Organism

Disease

Bacteria

Typhoid fever

Cholera

Bacterial Dysentery

Enteritis

Viruses

Infectious hepatitis

Parasitic Protozoa

Amoebic Dysentery

Giardiasis

Parasitic Worms

Shistosomiasis





Effects


Premature death of 3.4 million
people worldwide each year


Diarrhea

alone kills 2.1 million
people





How do we measure water quality?

Fecal Coliform Test

Drinking
water

0 colonies
per 100 ml

Swimming
water


200
colonies
per 100 ml





How do we measure water
quality?


Measuring the
level of
D
issolved
Oxygen (DO)

Fig. 19
-
3 p. 485





Biological Oxygen Demand
(BOD):


the amount of
dissolved
oxygen

needed by aerobic
decomposers to break down
organic matter.





How do we measure water
quality?


Using
chemical analysis


Presence and concentration



Using
indicator species


Filter feeding mussels,
macroinvertebrates






Sources of Water Pollution


Point Sources


Discharge of pollutants
at specific
locations

through pipes, ditches, or
sewers into bodies of surface
water.


Easier to control


Non
-
Point Sources



pollutants cannot be traced to any
single source of discharge


Difficult to control





Point and Nonpoint Sources

NONPOINT SOURCES

Urban streets

Suburban
development

Wastewater
treatment
plant

Rural homes

Cropland

Factory

Animal feedlot

POINT
SOURCES

Fig. 19
-
4

p. 486





Pollution of Streams


Can recover rapidly from oxygen
-
demanding
waste

Fig. 19
-
5 p. 488





Oxygen Sag





Pollution of Lakes


Slow turnover


Flushing and changing of water



Thermal stratification


Little vertical mixing



Biological Magnification


Increase in the concentration of chemicals in
organisms at successively higher trophic
levels of a food chain



Eutrophication


Natural nutrient enrichment of lakes





Water

0.000002 ppm

Phytoplankton

0.0025 ppm

Zooplankton

0.123

ppm

Rainbow smelt

1.04 ppm

Lake trout

4.83 ppm

Herring gull

124 ppm

Herring gull eggs

124 ppm

Biomagnification





Pollution of Lakes


Cultural
Eutrophication




Fig. 19
-
7 p. 491





Solutions: Preventing and Reducing
Surface Water Pollution

Nonpoint Sources

Point Sources


Reduce runoff


Buffer zone
vegetation


Reduce soil erosion


Clean Water Act


Water Quality Act





Fig. 21
-
8, p. 502

Water well

Migrating

vapor phase

Contaminant plume moves

with the groundwater

Free gasoline

dissolves in

groundwater

(dissolved

phase)

Groundwater

flow

Water

table

Gasoline

leakage plume

(liquid phase)

Leaking

tank






Groundwater Pollution
Prevention


Monitoring aquifers


Leak detection systems


Strictly regulating hazardous
waste disposal


Storing hazardous waste
materials above ground





Case Study: Chesapeake Bay


Largest US
estuary


Relatively shallow


Slow “flushing”
action to Atlantic


Major problems with dissolved O
2

Fig. 19
-
14
p. 500





OCEAN OIL POLLUTION


Most ocean oil pollution comes from
human activities on land
.



Studies have shown it takes about
3 years
for many forms of marine life to recover
from large amounts of
crude oil

(oil
directly from ground).



Recovery from exposure to
refined oil

(fuel
oil, gasoline, etc…) can take
10
-
20 years
for
marine life to recover.





OCEAN OIL POLLUTION


Tanker accidents
and blowouts at
offshore drilling
rigs can be
extremely
devastating to
marine life
(especially diving
birds, left).







Water
Break





Reducing Water Pollution
through Sewage Treatment


Septic tanks and various levels of
sewage treatment can reduce point
-
source water pollution.





Reducing Water Pollution
through Sewage Treatment


Raw sewage reaching a
municipal sewage
treatment plant

typically undergoes:



Primary sewage treatment
: a
physical

process
that uses screens and a grit tank to remove large
floating objects and allows settling.



Secondary sewage treatment
: a
biological

process
in which aerobic bacteria remove as much as 90%
of dissolved and biodegradable, oxygen demanding
organic wastes.





Reducing Water Pollution Through
Sewage Treatment


Primary and Secondary sewage
treatment.





Fig. 21
-
16, p. 511

Raw sewage

from sewers

Activated sludge

Disposed of

in landfill or
ocean or
applied to
cropland,

pasture, or
rangeland

Primary

Secondary

Grit chamber

Bar screen

Settling tank

Aeration tank

Settling tank


Chlorine

disinfection tank

Sludge drying bed

Sludge
digester

Air pump

To river,
lake,

or ocean

(kills bacteria)

Sludge





Reducing Water Pollution Through
Sewage Treatment


Advanced or
tertiary sewage treatment
:


Uses series of chemical and physical
processes to remove specific pollutants left
(
especially nitrates and phosphates
).



Water is
chlorinated

to remove
coloration and to kill disease
-
carrying
bacteria and some viruses (disinfect).





Technological Approach: Advanced
Sewage Treatment


Removes specific pollutants

Fig. 19
-
18

p. 505





2 million plastic bottles,

dumped every 5 minutes.

Is Bottled Water the Answer?





Is Bottled Water the Answer?


Some bottled water is not as pure
as tap water and costs much more.



1.4 million metric tons of
plastic
bottles

are thrown away.



Fossil fuels

are used to make
plastic bottles.


The oil used to produce plastic bottles in
the U.S. each year would fuel 100,000 cars.