11.2 Water Use and Management Page 296
How many people lack access to clean, reliable water? 1 Billion!
Global Water Use Agricultural Residential Industrial The amounts vary depending on area, but there are 3 major uses of water: Agricultural Residential Industrial
#1 - Residential water use Biggest amount differences in this worldwide Look at figure 5 on page 297 Which of the three main uses of water do most of the countries use? Agriculture Look at table 1. What is the biggest use of residential water? Lawn and pools
Water Treatment Water that is treated and made safe enough to drink is called POTABLE. Things it removes: 1. Mercury, lead, arsenic – from pollution or naturally 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 Treatment Steps: First Filtration – remove large organisms and trash Coagulation – Alum is rapidly mixed to form sticky globs called Flocs. Bacteria and other impurities cling to the it and settle to the bottom. Second Filtration – Layers of sand, gravel and coal filter Chlorination – chlorine added to prevent bacteria growth Aeration – air is forced thru water which releases gas & reduces odor and improves taste. Additional Treatment – fluoride may be added for teeth or lime/sodium to soften water.
Water Treatment Video http://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 Use Most water is used to cool power plants! 19% of water used in the world. Used to: manufacture goods Dispose of waste generate power ex – 1,000L = 1 kg aluminum 500,000L = car
#3 – Agricultural Water Use 67% of world wide water use 80% 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? B. 50% C. 86% D. 19%
Water that is safe enough to drink is called? Pathogens Potable Reservoir watershed
What is the first step to treating water? Coagulation Filtration Chlorination aeration
Water Management Water 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 Conservation 1. 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 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. Desalinification = process of removing salt from salt water. It consumes lots of energy which makes it expensive & therefore not an option for many.