WATER TECHNOLOGY – MODULE 1
DISTRIBUTION OF WATER ON EARTH
Oceans: 97.23 %
Ice caps and glaciers: 2.14 %
Groundwater: 0.61 %
Freshwater lakes: 0.01 %
Other: 0.01 %
CONTAMINANTS IN WATER
1) Industrial and commercial solvents
2) Metal and acid salts
3) Sediments
4) Pesticides, Herbicides
5) Plant nutrients
6) Radioactive materials
7) Vegetable matter
SOURCES OF WATER
1) Surface waters
• Rain water: Pure but contaminated with gases
• River water: Highly dissolved salts with moderate organics
• Lake water: Constant composition but high organics
• Sea water: Pathogens, high organics and high salinity
2) Underground waters
, • Spring/ well water: Crystal clear but highly dissolved salts, high purity from
organics
CLASSIFICATION OF IMPURITIES IN WATER
1) Physical
• Inorganics such as clay, sand, dissolved CO2, Sodium salts, silicates,
chlorides, nitrates and phosphates
• Organics such as oil globules, vegetable/ animal matter, detergents, fats,
water-borne organics
• Colloids such as Fe(OH)3, complex proteins and amines
2) Chemical
• Anions such as Cl-, SO42-, CO32-, HCO3-, NO3- of Ca and Mg
• Cations such as Ca2+, Mg2+, Na+, K+, Fe3+, Al3+
• Dissolved gases such as O2, N2, CO2, H2S, NH3
3) Biological
• Microorganisms such as Algae, Fungi, Bacteria
PROPERTIES OF WATER AFFECTED DUE TO CONTAMINANTS IN WATER
1) Color
• Color in water is due to metallic salts of Fe, Mn and due to organic
substances like humus, peat, algae, weed etc.
• Industrial activities such as textile, paper and pulp, and dyeing tanneries
affect the color of water
• Color intensities of water sample can be measured using tintometer with
Platinum cobalt standard color complex
2) Turbidity
• It is a measure of the relative clarity of water; the greater the turbidity, the
murkier is the water
, • Turbidity increases as a result of suspended solids in the water that reduce
the transmission of light
• With higher levels of turbidity, water loses its ability to support a diverse
aquatic organism
• It reflects the optical properties of water in terms of light scattering abilities
instead of transmitting in straight lines
3) Conductivity
• The ability of water to conduct electricity, indicates the number of
dissolved gases and minerals in water
• Conductivity is measured in micro mhos/ cm or micro-Siemens/ cm3
4) Taste
• Presence of dissolved salts and gases imparts bitter, soapy, brackish and
palatable taste which is normally co-related with odor but is not always
applicable.
• Bitter: Fe, Al, Mn, SO42-, Ca(OH)2
Soapy: (NaHCO3)
Brackish: NaCl
Palatable: CO2, NO3-
5) Odor
• Domestic and Industrial activities give undesirable odor to water
• Substances like algae, peat, bacteria affect odor
• Types of odor: Grassy, peaty, offensive, tarry and faint
HARDNESS OF WATER
• Hardness measures the concentration of multivalent cations, particularly
calcium and magnesium, present in water sample
• These ions precipitate easily and may form scales in hot water pipes, water
heaters and other appliances
• They also react with soap to form difficult to remove scum
DISTRIBUTION OF WATER ON EARTH
Oceans: 97.23 %
Ice caps and glaciers: 2.14 %
Groundwater: 0.61 %
Freshwater lakes: 0.01 %
Other: 0.01 %
CONTAMINANTS IN WATER
1) Industrial and commercial solvents
2) Metal and acid salts
3) Sediments
4) Pesticides, Herbicides
5) Plant nutrients
6) Radioactive materials
7) Vegetable matter
SOURCES OF WATER
1) Surface waters
• Rain water: Pure but contaminated with gases
• River water: Highly dissolved salts with moderate organics
• Lake water: Constant composition but high organics
• Sea water: Pathogens, high organics and high salinity
2) Underground waters
, • Spring/ well water: Crystal clear but highly dissolved salts, high purity from
organics
CLASSIFICATION OF IMPURITIES IN WATER
1) Physical
• Inorganics such as clay, sand, dissolved CO2, Sodium salts, silicates,
chlorides, nitrates and phosphates
• Organics such as oil globules, vegetable/ animal matter, detergents, fats,
water-borne organics
• Colloids such as Fe(OH)3, complex proteins and amines
2) Chemical
• Anions such as Cl-, SO42-, CO32-, HCO3-, NO3- of Ca and Mg
• Cations such as Ca2+, Mg2+, Na+, K+, Fe3+, Al3+
• Dissolved gases such as O2, N2, CO2, H2S, NH3
3) Biological
• Microorganisms such as Algae, Fungi, Bacteria
PROPERTIES OF WATER AFFECTED DUE TO CONTAMINANTS IN WATER
1) Color
• Color in water is due to metallic salts of Fe, Mn and due to organic
substances like humus, peat, algae, weed etc.
• Industrial activities such as textile, paper and pulp, and dyeing tanneries
affect the color of water
• Color intensities of water sample can be measured using tintometer with
Platinum cobalt standard color complex
2) Turbidity
• It is a measure of the relative clarity of water; the greater the turbidity, the
murkier is the water
, • Turbidity increases as a result of suspended solids in the water that reduce
the transmission of light
• With higher levels of turbidity, water loses its ability to support a diverse
aquatic organism
• It reflects the optical properties of water in terms of light scattering abilities
instead of transmitting in straight lines
3) Conductivity
• The ability of water to conduct electricity, indicates the number of
dissolved gases and minerals in water
• Conductivity is measured in micro mhos/ cm or micro-Siemens/ cm3
4) Taste
• Presence of dissolved salts and gases imparts bitter, soapy, brackish and
palatable taste which is normally co-related with odor but is not always
applicable.
• Bitter: Fe, Al, Mn, SO42-, Ca(OH)2
Soapy: (NaHCO3)
Brackish: NaCl
Palatable: CO2, NO3-
5) Odor
• Domestic and Industrial activities give undesirable odor to water
• Substances like algae, peat, bacteria affect odor
• Types of odor: Grassy, peaty, offensive, tarry and faint
HARDNESS OF WATER
• Hardness measures the concentration of multivalent cations, particularly
calcium and magnesium, present in water sample
• These ions precipitate easily and may form scales in hot water pipes, water
heaters and other appliances
• They also react with soap to form difficult to remove scum
