11.2 Water Use and Management

Page 296

How many people lack access to clean, reliable water?

1 Billion!

Global Water UseThe amounts vary depending on area, but

there are 3 major uses of water:

1.Agricultural2.Residential3.Industrial

#1 - Residential water useBiggest amount differences in this worldwide

Look at figure 5 on page 297WHICH OF THE THREE MAIN USES OF

WATER DO MOST OF THE COUNTRIES USE?

AGRICULTURELook at table 1. WHAT IS THE BIGGEST USE OF RESIDENTIAL WATER?

LAWN AND POOLS

Water TreatmentWater that is treated and made safe enough to drink

is called POTABLE.

Things it removes:1. Mercury, lead, arsenic – from pollution or naturally2. PATHOGENS – organisms that cause illness or

disease. - Could be from being contaminated by sewage or animal feces.

Ex. Bacteria, viruses, protozoa, parasitic worms

Pop Quiz! Not really…Try putting steps to

water treatment in the right order!

When you’re finished lets check them together.

Water TreatmentSteps:

1. First Filtration – remove large organisms and trash2. Coagulation – Alum is rapidly mixed to form sticky

globs called Flocs. Bacteria and other impurities cling to the it and settle to the bottom.

3. Second Filtration – Layers of sand, gravel and coal filter

4. Chlorination – chlorine added to prevent bacteria growth

5. Aeration – air is forced thru water which releases gas & reduces odor and improves taste.

6. Additional Treatment – fluoride may be added for teeth or lime/sodium to soften water.

Water Treatment Videohttp://video.search.yahoo.com/video/

play;_ylt=A2KLqIUwPztU8ywAzxL7w8QF;_ylu=X3oDMTBzc2M2MjdyBHNlYwNzcgRzbGsDdmlkBHZ0aWQDBGdwb3MDMTE-?p=water+treatment&vid=46b67530b0fd0440e97439caabf57260&l=3%3A21&turl=http%3A%2F%2Fts3.mm.bing.net%2Fth%3Fid%3DVN.608029647015055306%26pid%3D15.1&rurl=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D9z14l51ISwg&tit=The+water+treatment+process&c=0&sigr=11apvvi21&sigt=10rifh4r6&age=0&hsimp=yhs-fullyhosted_003&hspart=ironsource&type=ast_dsites03_14_31_ie&tt=b

#2 - Industrial Water Use19% of water used in

the world.

Used to:1. manufacture goods2. Dispose of waste3. generate power

ex – 1,000L = 1 kg aluminum

500,000L = car

Most water is used to cool power plants!

#3 – Agricultural Water Use67% of world wide

water use80% of water used

in AGR. Evaporates before it reaches the plant roots.

In the U.S. the most common method is

inefficient.

What % of water is used for industry?A. 100%B. 50%C. 86%D. 19%

Water that is safe enough to drink is called?a. Pathogensb. Potablec. Reservoird. watershed

What is the first step to treating water?a.Coagulatio

nb.Filtrationc.Chlorinatio

nd.aeration

Water ManagementWater Diversions – rivers can be diverted to carry water great distances that need it. (AQUADUCT)

Dams are built across a river to control the flow and Reservoirs build up behind it. Benefits: generate electricity, flood control, drinking, irrigation Cons: flooded ecosystems, blocks sediment to land below, breakage = death.

Water Conservation1. In Agriculture: Drip irrigation – delivers water to roots 2. In Industry: Plans devised to conserve. The biggest is recycling cooling water and wastewater.3. At home: low flow toilets/showers, water lawns at night, xeriscaping, turn off water when shaving/brushing teeth, wash only when full loads, etc.

Solutions for the future

Desalinification= process of removing salt

from salt water.It consumes lots of energy which

makes it expensive &

therefore not an option for many.

Transporting Fresh Water

Ships can tow water from where available to where its needed in large plastic bags.We are looking at doing this

in alaska to CA.Towing Icebergs to areas, but we don’t know how to

efficiently do this yet.