Civil books


Download free books

Free Download

10 Mar 2014

Chemical Characterstics of water

Total solids and Suspended solids

  • The total amount of solids and suspended solids can be determine by evaporating of sample of water and weighing dry residue left.
  • The permissible limits of solids in water is 500 ppm and for the higher amoiutn is 1000 ppm
2. Ph Value

  • The Ph value indicates the hydrogen ions present in the water thus its indicates the acidity and alkanity of water.
  • If the ph value is high, it means that lower hydrogen concentration  present in water thus it indicates the alkanity of water.
  • If pH value is low , it means that higher hydrogen concentration present in the the water. Thus it indicates the acidity of water.
  • In the pure water +ve and -ve ions are equal.
  •  and product of concentration H+ and OH- are constant and equal to (1*10^-14) moles/litre.
  • log10(1/H+) = Log10(1/10^-7) =Log10^10^7 = 7
  • If Ph value of water < 7 called acidic water
  • If Ph value of water > 7, called alkanile water
3. Hardness of Water

  • The hardness of water is caused by the calcium and megnacium salt present in the water whics form scum by the reaction with soam.
  •  hardness of water may lead to consumption of soam, causing of corrosion and incrustation of pipes and also makin food taste less.
  • If bicarbonated and carbonatesof calcium, magniciun present in water the water is rendered temporary hard .The hardness can be removed by boiling of water, or by adding lime called temporary hardness or carbonate hardness
  • when the sulphate chloride and nitrate of calcium or magnicium are present in the water and they can't be removed by boiling and need to special treatment , called permanent hardness of water or non carbonate of water.
  • the water which contain 75 pp hardness , concidere safe water.
  • And  200 ppm and above concidered hard water
  • the under ground water are hardend due to the presene of minerals and contain  hardness 300 ppm.
  • for the boile feed water,washing etc water must be contain hardness lessthan 75 ppm. because below the 75 ppm water is tastless and generally used for drinking purpose
  • The prescribe limit of water for public supply is 75 ppm to 115 ppm.

No comments:

civil engineering techniquest

Jobs in civil engineering