Слайд 2: The King River
The King river in Tasmania is thought to be the most polluted river in Australia. For about 70 years, it was used to dump the mining waste from a nearby copper mine. It’s now so acidic that nothing can live in it. Photo courtesy of Riverhugger - granted under creative commons licence – attribution
Слайд 3: Murray-Darling Basin
The major water source for food production in Australia is the Murray-Darling basin. This river system has become unhealthy due to the overuse of the water and pollution flowing into it from different sources. The challenge for Australia is to make sure the water in the basin is managed sustainably.
Слайд 4: River Rubbish
River pollution can have serious effects. Fresh water can become so polluted that plants and animals can die. Rubbish can be dumped in rivers rather than placed into bins. Pesticides and fertilisers put on crops can be washed into rivers. Waste materials from factories can be piped into rivers.
Слайд 5: Interesting Fact!
The Rhine is one of the longest and dirtiest rivers in Europe. In 1986, after a fire at a factory in Switzerland, more than 30,000kg of chemicals spilled into the river. For about 200km downstream, all living things died. Photos courtesy of sfmission.com, Kecko, onnola (@flickr.com) - granted under creative commons licence – attribution
Слайд 6: Interesting Fact!
Our drinking water comes from the water in the water cycle. It is filtered and purified before it reaches our taps. Not all countries are fortunate enough to have this. Some have very basic water filters to make their water clean to drink.
Слайд 7: Making a Water Filter
You can make your own water filter using a plastic bottle, sand, water, soil, a paper coffee filter and a jug. What you will need:
Слайд 8: Making a Water Filter
Carefully cut the top from your plastic bottle about 10cm down from the lid. Place the top upside down inside the bottle and tap it firmly into place. Position the filter paper inside the bottle top. Spoon a layer of sand into the filter. Pour enough water on to the sand to make it wet. Mix soil and water into the jug. Slowly pour the muddy mixture on to the wet sand inside the filter. Watch the water pass through the sand and collect in the bottom of the bottle.
Слайд 9: Making a Water Filter
Now, study the water in the bottom of the bottle. It will look cleaner; however, it is definitely not fit to drink! Our drinking water is filtered many times before it’s ready to drink. Compare your filtered water with tap water and see if there is a difference.
Слайд 10: Filtration
Water filters can use two different techniques to remove dirt. Physical filtration means straining water to remove larger impurities. Another method of filtering, chemical filtration, involves passing water through a chemical that removes impurities.