Freshwater and Ocean

sadhospitalMechanics

Feb 22, 2014 (3 years and 8 months ago)

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Freshwater and Ocean
Pollution

Chapter 11

Water Pollution


Intro of chemical, physical, or
biological agents


Degrades quality


Affects organisms


Industrialization and human
population explosion cause it!

Point Pollution


Discharged from a single source


Examples


Septic tanks, storage lagoons,
oil tanker, wastewater treatment
plant, landfills

Nonpoint Pollution


Comes from many sources
instead of a specific site


Examples


Storm water runoff, pesticides
& fertilizer off farmland, road
salt, highway construction

Pre Consumption Water
Treatment


First Filtration
(big items)


Coagulation

(alum) and
Sedimentation

(sludge)


Second Filtration
(layers of sand, coal,
gravel)


Chlorination


Aeration
(reduce odor, improve taste)


Optional treatments
(fluoride, softener)



http://www.ogwa
-
hydrog.ca/en/taxonomy/term/94

Wastewater Treatment


Filtration


Coagulation

(alum) and
Sedimentation

(sludge)


Aeration

and bacterial action


Sedimentation

(sludge


again)


Disinfection

(traditionally chlorine, UV is
emerging technology)

http://www.sawater.com.au/SAWater/Education/OurWastewaterSystems/Wastewater+Treatment+Process.htm

Pathogens



Mainly come untreated
wastewater (human feces) or
animal feces


Escherichia coli
or
E. coli


Fecal coliform test checks for it

Eutrophication


Excess phosphorus from
detergents and fertilizers gets
into water


Causes algae to bloom, die, and
use oxygen which kills animals

Thermal Pollution


Excess heat added to surface
water by power plants & industry


Lowers oxygen level in water


Kills fish

Cleaning up Water Pollution


Clean Water Act 1972


Point pollution easier to clean


Agricultural and industrial
lagoons to trap runoff and
decompose pollutants


Groundwater Pollution
Problems


Groundwater recharges very
slowly, so water will be
polluted for a long time


Hard to decontaminate since
between sand and rocks and it
clings to sand grains

Bottled Water


Usually just filtered tap water


May have chemicals added for
taste


Not tested for pollutants as
often as public water supply

Ocean Pollution


At least 85% of pollution comes
from activities on land


Rivers carry polluted runoff
into ocean


Coastal population garbage

Ocean Pollution (cont’d)


Some materials dumped
directly into ocean


sludge,
ship garbage


Accidental oil spills (Exxon
Valdez in Prince Wm. Sound)


Plastic

Preventing Ocean Pollution


International laws exist but are hard
to enforce
-
Law of the Sea treaty


Territorial sea
extends 22 km (12
mi) from coast


Exclusive economic zone
extends
370 km (200 mi) from coast

Innovative Solution to Plastic
Pollution in the Ocean


http://www.youtube.com/watch?v=ROW9F
-
c0kIQ



Thanks,
Maddie

Beban
!

CASE STUDY

Deepwater Horizon

BP Oil Spill

April


August 2010

Deepwater Horizon

(BP) Oil Spill 2010


Largest spill to date


Caused by explosion 50 miles SE of
Mississippi River Delta on April 20, 2010


The rig sank on April 22, 2010 in 5,000
(almost 1 mile) feet of water


11 workers died in the explosion

http://www.eoearth.org/article/Deepwater_Horizon_oil_spill

Initial Video


http://www.youtube.com/watch?v=DyOBIr
slw5w&feature=player_embedded



http://www.youtube.com/watch?v=hMajtD
TyTnE



Deepwater Horizon

(BP) Oil Spill 2010


Crude oil continued leaking
from the underwater pipe until
“BP announced that oil
stopped flowing at 2:25 p.m.
on July 15 after the last of
several valves was closed on
the cap at the top of the well,
marking the first time in 86
days that oil was not flowing
into the Gulf.”

How Much Oil?


BP originally said the oil was leaking at about 5,000
barrels per day.


Dr. Timothy Crone, a marine geophysicist at Columbia
University estimated that 50,000 to 100,000
bbls
/day


Dr. Eugene Chiang, an astrophysicist at the University of
California at Berkeley, estimated the total flux from the
end of the riser to be between 20,000 and 100,000
bbls
/day.


Dr. Steven
Wereley
, a mechanical engineer at Purdue
University and expert in fluid mechanics, estimated that
the total was 72,179
bbls
/day (
±
20%).




Fate of oil released by the Deepwater Horizon Disaster. Source: National Incident Command Center