Freshwater

1. Physco-Chemical characteristic of fresh water
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2. Water?
Chemical Compound (H2O)
Liquid Gas
Solid
Condensation
Evaporation
All life on earth depends on water.
Water is not only essential to life but it is predominant inorganic
constituent of living matter forming in general
The Sources of water such as atmospheric water (rain water),
surface water, store water, ground water
Water states
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3. Physical properties of water
1. Color
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4. 2. Odor and teste Sandip Rathod

5. 3. Temperature
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6. 4. Transparency
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7. 5. Turbidity
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8. Chemical properties of water
1. pH
2. Electrical conductivity (EC)
3. Total dissolve solid (TDS)
4. Dissolve oxygen (DO)
5. Free carbon dioxide (co2)
6. Alkanity
7. Hardness of water
8. Chlorides
9. Sulphates
10.Hydrogen sulphates(H2o)
11. calcium
12.Magnesium
13.Sodium
14.Potassium and Iron
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9. 1. pH
pH is scale of intensity of acid or alkanlity and measure the concentration of ion in water. If the
free H+ ion more than OH-, the water will be acidic.
pH of natural water varies around 7.
Generally over 7 i.e. alkaline due to the presence of sufficient quantities of carbonate
It increase during day time largely due to photosynthesis where as decrease at night due to the
respiratory activity.
Factors like temperature, disposal of waste from industries etc.
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10. 2. Electrical conductivity:
Pure water is poor conductor of electricity, acid, base and salt makes it relatively good
conductor of electricity. Such substance are called as electrolytes
Those with poor solubility in water are called weak electrolyte and those with high solubility
known as strong electrolyte.
In other words electrolyte in a solution dissociated into +ve (cation)and –ve (anion)
Ions and impart conductivity. Thus higher the concentration of electrolytes in water the more is
its electrical conductance.
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11. 3. Total Dissolve solutes (TDS)
A large number of salt are found dissolved in water such as carbonates, bicarbonates,
chloride, sulphate, phosphates, nitrates, calcium, magnesium, sodium potassium.
A high content dissolve solute elevates the density of water, influence osmoregulation of fresh
water organism as well as the marine water organism.
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12. 4. Dissolve oxygen: (o2)
Dissolve oxygen is one of the most important chemical property which has a great influence on the
survival and growth of organism.
There are two main sources of dissolve oxygen in water means diffuse air and photosynthetic
activity within water.
During day time reaches a maximum at 3 pm then gradually decrease up to early morning
During night time it decrease due to lack of photosynthesis.
The photosynthesis is a biological activity carried by autotrophs and depends upon the autotrophic
population, light condition and availability of gases etc.
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13. 5. Free co2
Carbon dioxide is production during respiration and consumed during photosynthesis co2 is less
during day time and more at night.
The respiratory activity of aquatic organism and the process of decomposition is the important
sources of carbon dioxide in bodies of surface water.
Free carbon dioxide combines with water partly to form carbonic acid (H2CO3) as such in normal
practice free co2 is distinguished as co2 and carbonic acid
CO2 + H2O H2CO3 (carbonic acid)
Water containing free co2 react to limestone calcium carbonate free Carbon dioxide dissolve in water
is thus, the only source of carbon that be used in photosynthesis activity of aquatic autotrophs.
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14. 6. Alkalinity:
Alkalinity is caused by carbonates, bicarbonates or hydroxides of calcium, mg, na, K and iron.
Alkalinity of Water in its capacity to neutralize a strong acid and is characterized the presence of
hydroxyl ions.
Thus, alkalinity may be expressed as total alkalinity due to individual bases.
The optimum level of total alkalinity is 40-150 ppm.
It has direct effect on the production of plankton.
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15. 7. Hardness of water
The total hardness of water is the sum of concentration of alkaline earth metal cations present in
it.
Calcium and magnesium are principal substances imparting (causing) hardness water with less
than 40 ppm is hard
Hardness when caused because of bicarbonates and carbonates of the cations is called
temporary hardness and can be removed by boiling the water.
Therefor hardness of water prevents bathing and washing in to water
Hard water is not suitable for cooking too because high boiling point.
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16. 8. Chlorides
In land natural water (fresh Water) have low chlorides concentration while saline water of
coastal estuaries and sea having very high chloride content.
In natural fresh h2o, high concentration of chloride is considered to be and indication of
pollution due to organic waste of animal origin.
Salinity is an important parameter for survival, growth and high production is cultural system.
Chloride contents about 250 mg/lit. makes a water salty in taste but a level up to 1000 mg/lit is
safe for human consumption.
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17. 9. Sulphates:
Sulphates are found in appreciable quantity in all natural waters. Domestic sewage and
industrial effluents many add to sulphates continent of water.
10. Hydrogen sulphide (H2S)
H2s is produce in anaerobic condition by the action of micro-organism on sulphur compounds.
H2S is toxic to organism. It should be less than 0.05 ppm For Aquatic Biota.
In pond water H2S is responsible for respiratory problem. When it is increase always lime should
be added.
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18. 12. Calcium:
Calcium is found in great abundance in all natural water and its source lies in the rocks.
Calcium is an important micro nutrients in an aquatic environment.
It is needed in large quantities by the Mollusca and vertebrate.
13. Magnesium:
Magnesium is the necessary constituent for chlorophyll production and its useful for aquatic plant
14. Sodium:
In saline and brackish water the concentration of sodium is remarkly high and limits the biological
diversity due to osmotic trace.
salt are highly soluble in water and causing softness to Water
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19. 15. Potassium:
Presence of potassium plays the vital role in the metabolism of freshwater environment and
considered to be an important macronutrients.
16. Iron:
iron is found in all natural water oxidized (ferric) and reduced (ferrous) forms.
It is an important plant nutrients consider to be quantitively the most important trace metal for
autotrophs.
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20. Biological properties of water
1. Macrophyte:
2. Phytoplankton:
3. Zooplankton:
4. Saprophytes (Disease causing Agent):
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21. 1.Macrophytes:
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22. 2. Phytoplankton:
3. Zooplankton:
4. Saprophytes:
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