point source - Edmond Public Schools

swedishstreakMécanique

22 févr. 2014 (il y a 3 années et 5 mois)

52 vue(s)

Chapter 21

Jesus Ramirez

Jake
McCleery


eutrophication



Physical, chemical, and
biological changes that take
place after a lake, estuary,
or slow
-
flowing stream
receives inputs of plant
nutrients mostly nitrates
and phosphates from
natural erosion and runoff
from the surrounding land
basin. See cultural
eutrophication
.

What pollutes water, where do these
pollutants come from, and what
effects they have?


Water is polluted by disease
-
causing agents,
oxygen demanding wastes, plant nutrients,
organic and inorganic chemicals, sediment,
and excess heat.


nonpoint source
Large or dispersed land areas such as
crop fields, streets, and lawns that discharge pollutants
into the environment over a large area. Compare point
source.


point source
Single identifiable source that discharges
pollutants into the environment. Examples are the
smokestack of a power plant or an industrial plant,
drainpipe of a meatpacking plant, chimney of a house,
or exhaust pipe of an automobile. Compare nonpoint
source.



oxygen
-
demanding wastes


Organic materials that are usually
biodegraded by aerobic (oxygen
-
consuming)
bacteria if there is enough dissolved oxygen in
the water. See also biological oxygen demand.



primary sewage treatment


Single identifiable source
that discharges pollutants
into the environment.
Examples are the
smokestack of a power
plant or an industrial
plant, drainpipe of a
meatpacking plant,
chimney of a house, or
exhaust pipe of an
automobile. Compare
nonpoint source

What are the major water pollution
problems in streams and lakes?





Factory waste, untreated sewage waste




primary sewage treatment
Mechanical sewage
treatment in which large solids are filtered out by
screens and suspended solids settle out as sludge in
a sedimentation tank. Compare advanced sewage
treatment, secondary sewage treatment.


septic tank
Underground tank for treating
wastewater from a home in rural and suburban
areas. Bacteria in the tank decompose organic
wastes, and the sludge settles to the bottom of the
tank. The effluent flows out of the tank into the
ground through a field of drainpipes.


What causes groundwater pollution,
and how can it be prevented?



Groundwater can become contaminated with
a variety of chemicals because it cannot
effectively cleanse itself and dilute and
disperse pollutants.


Better monitoring of underground gas tanks

Prevent oil spills.

Better testing for aquifers.


Sludge

Gooey mixture of toxic chemicals,
infectious agents, and settled solids removed
from wastewater at a sewage treatment plant.



tertiary (higher
-
level) consumers
Animals
that feed on animal
-
eating animals. They feed
at high
trophic

levels in food chains and webs.
Examples are hawks, lions, bass, and sharks.
Compare
detritivore
, primary consumer,
secondary consumer


What are the major water pollution
problems affecting oceans?


Pollution in the ocean directly affects ocean
organisms and indirectly affects human health
and resources. Oil spills, toxic wastes, and
dumping of other harmful materials are all
major sources of pollution in the ocean.
People should learn more about these
because if people know more about pollution
in the ocean, then they will know more about
how to stop pollution.

How safe is drinking water, and how
can it be made safer?


Water treatment plants and watershed
protection can provide countries. Simpler and
cheaper ways can be used to purify drinking
water for individuals and villages in
developing countries.


tertiary sewage treatment
A
process for
purification of wastewater in which nitrates and
phosphates, as well as fine particles, are
removed; the process follows removal of raw
sludge and biological treatment. Also known as
advanced sewage
treatment.


water pollution
Any physical or chemical change
in surface water or groundwater that can harm
living organisms or make water unfit for certain
uses.