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WATER QUALITY PARAMETERS
Water quality parameters are broadly divided in three categories physical parameters,
chemical parameters, and biological parameters [10-11].
Physical Parameters
Turbidity
It is the ability of ligt to pass through water and can be stated as cloudiness of water caused
due to various suspended materials such as clay, silt and other particulate maters [12-13].
Temperature
It is an important parameter that regulates the viscocity, odors, solubility, chemical reactions,
palatability, sedimentation, chlorination and thereby biological oxygen demand (BOD) [13-
14].
Color
Decayed organic material such as wastes and dead remains from flora and fauna, vegetation
and inorganic materials such as rocks, stones and soil impart color to water. Color is graded
on 0 to 70 units where pure water is equivalent to 0 color unit [13, 15].
Taste and odor
Pure water is colorless and tasteless. Change in taste and odor of water is due to addition of
external materials such as inorganic, organic or dissolved substances [16-17].
Solids
Solids in water occur in two either in solution or in suspension forms. Dissolved solids pass
through the filter easily while suspended solids cannot pass through the filters [13, 18].
Water on the basis of TDS can be categorised as:
Freshwater <1500 mg/L TDS;
Brackish water 1500–5000 mg/L TDS;
Saline water >5000 mg/L TDS.
Chemical Parameters
pH
It is one of the most principal parameters of water quality index. pH of solution is taken as
+
negative logarithmic value of hydrogen ion [H ] concentration [11, 19]. It is the
dimensionless unit that gives the degree of acidic or basic nature of any solution or water. Its
value range from 0-14 where pH range 7 to 14 represents alkalinity and 0 to 7 represents
acidity while 7 represents neutrality. pH of drinking water lies between 6.5 to 8.5 [12, 20-21].
Pollution can alter the pH of water making it unfit to be used by animals and plants.
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