C3 Water Treatment

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  • Created by: Théa
  • Created on: 18-05-13 18:22

What do we need removed from water?

-Bacteria, viruses, microbes and microorganisms (biological impurities)



-Poisonous Salts

-Insoluble Impurities (mud, remains of animals + plants, etc)

-Soluble impurities (minerals)

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Tap and Laboratory Water

Tap Water

-Must be free from impurities harmful to health, so must contain only low levels of dissolved substances and microorganisms.

Laboratory Water

-Must be free from ALL impurities

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Water Treatment: Stage 1

Screening Out Solids

-Screens of progressively finer mesh remove big chunks of solid

-Water that leaves after this contains: small particles, minerals, microorganisms, and pollutants

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Water Treatment: Stage 2


-The water is then passed through to a settlement tank where sand and soil settle out

-Alluminium sulphate and lime are added, making small dirt particles clump together and settle out

-The collected sludge goes to landfill

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Water Treatment: Stage 3


-On an industrial scale, gravel beds or fine sand are used for filtering

-The ions and molecules of dissolved solids are small enough to pass, so the water still contains dissolved solids and microorganisms afterwards

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Water Treatment: Stage 4


-The water LOOKS clean after filtering, but still contains soluble impurities and bacteria

-Adding a small amount of chlorine will kill the bacteria, without doing us harm

-After checking the pH of the water and altering it if need, the water is suitable to drink

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-It can prevent tooth decay

-It protects people with a poor dental hygiene

-There are places which have had fluoridated water for a long time and haven't suffered from any problems, or seen any harmful effects



-Can lead to bone cancer in excess

-Ethical issue of people not being consented to it

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