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Water AnalysisThe following goals may be formulated for the examination of water:Determination of physical, chemical & biological characteristics of water.Determination of pollution sources.Feasibility of water for different purposes e.g, drinking, industrial, irrigation etc.Type and size of treatment units required.Determination of amount of chemicals required for purification and conditioning of water for industrial usage.*

General Water Analysis Parameters*

ColorPure water is colorless. However color is contributed to natural water by many sources.Sources:End products of organic matter degradationDivalent ions of iron & manganese in both ground & surface water. *

ColorColor caused by suspended matter is called apparent color.Color caused by dissolved solids that remains after removal of suspended solids is called true color.Color Removal:Apparent color is removed by simple filtration or ultra filtration.True color causing organic compounds require chlorine demand.

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pHpH is the method of expressing the concentration of ionized hydrogen.It is the logarithms to base 10, of the reciprocal of hydrogen ion conc. in g/L.Pure water has equal conc. Of hydrogen & hydroxyl ions and has pH of 7 (neutral).11/10/11*

pHpH of natural water lies in the range of 6.0 to 8.5.Most of natural water is alkaline due to the presence of carbonates.pH of natural water changes due to biological activity, photosynthesis, and industrial disposal.pH is one of the important parameter in water treatment.

11/10/11*

Electrical ConductivityIt is the measure of the capacity of the substance or solution to carry an electric current.It is a parameter for dissolved solids.Its value depend on conc. Of ions, temperature and the migration velocity of the ions.

11/10/11*

Electrical ConductivityIt helps in estimating the total dissolved solids by following empirical relation:

TDS(mg/L) = C * Electrical Conductivity

Where C is empirical factor may vary from 0.55 to 0.9 depending on the soluble solids present in water.*

Turbidity

The suspended solids interfering with the passage of light is called turbidity.Sources:ClayResiduesOrganic matter & metalsMicroscopic organisms*

TurbidityTurbidity is measured by determining %age of light of a given intensity absorbed or scattered. Units are:

NTU (Nephlometric Turbidity Unit) based on light scatteringFNU (Formazin Nephelometric Unit) based on light scatteringFTU (Formazin Turbidity Unit) based on light absorptionJTU (Jackson Turbidity Unit) based on light absorption

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SolidsOrganic SolidsSolids are about 50 percent organic. This fraction is generally of animal or vegetable life and synthetic organic compounds. Inorganic SolidsInorganic solids are substances that are inert and not subject to decay. Inorganic solids include sand, gravel as well as the mineral salts etc.

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SolidsSolids can also be grouped depending on their physical state as suspended solids, colloidal solids and dissolved solids, each of which can include both organic and inorganic solids.Suspended SolidsSuspended solids are those which are visible and in suspension in the water. They are the solids which can be removed from the wastewater by physical or mechanical means, such as sedimentation or filtration e.g. sand, clay, paper, pieces of wood, particles of food and garbage, and similar materials.

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SolidsSettleable SolidsSettleable solids are that portion of the suspended solids which are of sufficient size and weight to settle in a given period of time, usually one hour. Colloidal SolidsColloidal suspended solids are solids that are not truly dissolved and yet do not settle readily. These are somewhat loosely defined as the differences between the suspended solids and the settleable solids

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SolidsDissolved solidsDissolved solids are invisible and smaller in size than suspended and colloidal solids. As used, the term means all of the solids which pass through the filter paper. Total SolidsTotal solids, as the term implies, includes all of the solid constituents of a wastewater. Total solids are the total of the organic and inorganic solids or the total of the suspended and dissolved solids.

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