Water in lakes, rivers, and swamps often contains impurities that make it look and smell bad. The water may also contain bacteria and other microbiological organisms that can cause disease. Have students describe the appearance and smell of the water.
Aeration is the addition of air to water.
It allows gases trapped in the water to escape and adds oxygen to the water. Place the cap on the bottle and shake the water vigorously for 30 seconds. Ask students to describe any changes they observe. Pour the aerated water into a bottle with its top cut off. With the tablespoon, add 20 g of alum crystals to the swamp water.