Water Treatment Screening - Clean water passes through the screen and large objects do not pass Sedimentation - Aluminium Sulphate is added. It is mixed slowly and then allowed to settle. Filtration – passes through sand Add chlorine to kill bacteria. Add flourine to prevent tooth decay.
Water separated into gases using electricity Some acid must be added to increase conduction
Algal Bloom Too much fertiliser or food waste can feed algae causing a harmful algal bloom This uses up all the oxygen and kills fish
Hard and soft water Add soap and mix Add Soap solution Hard Water Few Bubbles Oily scum Soft Water Lots of Bubbles
Hard Water Contains dissolved calcium and magnesium ions Forms scum when soap is used Scale on inside of pipes and kettles
Where hard water comes from Acid Rain Limestone Water dissolves the limestone (Calcium Carbonate) and the calcium ions make the water hard Water that runs off straight to rivers and lakes is soft water
Removing Hardness from water Distillation Ion exchange with Zeolite resins Soft water better for industry and plumbing Hard water better for your heart
Advantages and Disadvantages of Hard and Soft Water AdvantageDisadvantage Hard Good for Heart and Beer Scale in pipes Soft Good for washing clothes Girl children