8/10/2019 Questions TDS

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QUESTIONS:

1.

Explain on TDS

Total Dissolved Solids (often abbreviated TDS) is a measure of the combined content of

allinorganic andorganic substances contained in a liquid (molecular, ionized or micro-granular

suspended form). Generally the operational definition is that the solids must be small enough to survive

filtration through a sieve the size of two micrometer. Total dissolved solids are normally discussed only

for freshwater systems, as salinity comprises some of the ions constituting the definition of TDS. The

principal application of TDS is in the study ofwater quality forstreams,rivers andlakes,although TDS is

not generally considered a primary pollutant (it is not deemed to be associated with health effects). So,

it is used as an indication of aesthetic characteristics ofdrinking water and as an aggregate indicator of

the presence of a broad array of chemical contaminants.

Primary sources for TDS in receiving waters are agricultural and residential runoff, leaching of

soil contamination and point source water pollution discharge from industrial or sewage treatment

plants. The most common chemical constituents are calcium, phosphates, nitrates, sodium, potassium

chloride, which are found in nutrient runoff, general storm water runoff and runoff from snowy climates

where road de-icing salts are applied. The chemicals may becations,anions,molecules or

agglomerations on the order of one thousand or fewer molecules, so long as a soluble micro-granule is

formed. More exotic and harmful elements of TDS arepesticides arising fromsurface runoff. Certain

naturally occurring total dissolved solids arise from the weathering and dissolution of rocks and soils.

TheUnited States has established a secondary water quality standard of 500 mg/l to provide for

palatability of drinking water.

Total dissolved solids are differentiated from total suspended solids (TSS), in that the latter

cannot pass through a sieve of two micrometers and yet are indefinitely suspended in solution. The term

"settleable solids" refers to material of any size that will not remain suspended or dissolved in a holding

tank not subject to motion, and excludes both TDS and TSS. Settleable solids may include larger

particulate matter or insoluble molecules.

http://en.wikipedia.org/wiki/Inorganichttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Water_qualityhttp://en.wikipedia.org/wiki/Streamhttp://en.wikipedia.org/wiki/Riverhttp://en.wikipedia.org/wiki/Lakehttp://en.wikipedia.org/wiki/Drinking_waterhttp://en.wikipedia.org/wiki/Cationhttp://en.wikipedia.org/wiki/Anionhttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Granulehttp://en.wikipedia.org/wiki/Pesticidehttp://en.wikipedia.org/wiki/Surface_runoffhttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/Total_suspended_solidshttp://en.wikipedia.org/wiki/Total_suspended_solidshttp://en.wikipedia.org/wiki/United_Stateshttp://en.wikipedia.org/wiki/Surface_runoffhttp://en.wikipedia.org/wiki/Pesticidehttp://en.wikipedia.org/wiki/Granulehttp://en.wikipedia.org/wiki/Moleculehttp://en.wikipedia.org/wiki/Anionhttp://en.wikipedia.org/wiki/Cationhttp://en.wikipedia.org/wiki/Drinking_waterhttp://en.wikipedia.org/wiki/Lakehttp://en.wikipedia.org/wiki/Riverhttp://en.wikipedia.org/wiki/Streamhttp://en.wikipedia.org/wiki/Water_qualityhttp://en.wikipedia.org/wiki/Organic_compoundhttp://en.wikipedia.org/wiki/Inorganic

8/10/2019 Questions TDS

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2.

How does TDS affect the human health?

TDS does not directly pose a health risk. However, certain specific ions such as nitrate

that are present in water can pose a direct health risk. High levels of major ions, such as sodium,

magnesium, and sulphate, may cause transient diarrhea. Generally, it is aesthetic problems such

as taste, odor, and appearance that arise from high concentrations of TDS. These aesthetic

problems are often an indicator of corrosiveness, scaling, and ineffectiveness of detergents.