Water Chemistry
1
, Sources of water
Surface water:
– Rain water: Purest form of water.
– River water: Contains dissolved chlorides,
sulfates & bicarbonates of Na, Mg, Ca & Fe.
– Lake water: Less minerals, high organic matter.
– Sea water: Most impure form, containing
dissolved salts.
• Underground water
– Spring water
– Well water
2
, Impurities
Physical impurities
Chemical impurities Biological impurities
H2O
Organic impurities Total Dissolved Solids (TDS)
Need to improve the quality of the water
https://www.livpuresmart.com/blog/types-of-impurities-in-drinking-
water/#:~:text=Biological%20impurities%20in%20water%20include,posing%20a%20severe%20health%20risk.&text=Chemical%20impurities
%20in%20water%20enter%20water%20from%20industrial%20agricultural%20or%20natural%20processes.
3
, 1. Physical Impurities
Physical impurities: Visible
particles/materials present
which includes sediment,
sand, rust, and debris. -
Mainly affect water clarity
and taste.
Type Example Effect
Clay, slit, finely divided matter Turbidity
Unusual amounts of salts Brackish taste
Fe, Mn, Al, SO4-2, excess of lime Bitter taste
Colloidal Large amount of Na2CO3 Soapy taste
impurities Dissolved CO2 & nitrates Palatable taste
https://www.aakash.ac.in/important-concepts/chemistry/purification-of-colloids
4
1
, Sources of water
Surface water:
– Rain water: Purest form of water.
– River water: Contains dissolved chlorides,
sulfates & bicarbonates of Na, Mg, Ca & Fe.
– Lake water: Less minerals, high organic matter.
– Sea water: Most impure form, containing
dissolved salts.
• Underground water
– Spring water
– Well water
2
, Impurities
Physical impurities
Chemical impurities Biological impurities
H2O
Organic impurities Total Dissolved Solids (TDS)
Need to improve the quality of the water
https://www.livpuresmart.com/blog/types-of-impurities-in-drinking-
water/#:~:text=Biological%20impurities%20in%20water%20include,posing%20a%20severe%20health%20risk.&text=Chemical%20impurities
%20in%20water%20enter%20water%20from%20industrial%20agricultural%20or%20natural%20processes.
3
, 1. Physical Impurities
Physical impurities: Visible
particles/materials present
which includes sediment,
sand, rust, and debris. -
Mainly affect water clarity
and taste.
Type Example Effect
Clay, slit, finely divided matter Turbidity
Unusual amounts of salts Brackish taste
Fe, Mn, Al, SO4-2, excess of lime Bitter taste
Colloidal Large amount of Na2CO3 Soapy taste
impurities Dissolved CO2 & nitrates Palatable taste
https://www.aakash.ac.in/important-concepts/chemistry/purification-of-colloids
4
