Define water? Classification of water?

Water:

Water is a complex compound. It is very important compound in textile wet processing. The total amount of water in the world is about 75%. Natural water is obtained in 3 steps. They are solid, liquid & vapor. Water has a un-comparable power to dissolve other compound. It is very difficult to obtain pure water in nature. Water is consists of two part Hydrogen & one part Oxygen. Its chemical formula is H2O. Water is converted to ice at 0°C & converted to vapor at 100°C the concentration of water is highest at 4°C.
 
Classification of water:


Classify water on the basis of hardness:
DESCRIPTION
TOTAL HARDNESS (degree)
Very soft
0 -
Soft
5 -
Mild
9 - 14°
Fairly mild
15 - 18°
Hard
19 - 30°
Very hard
>30°
 
Classify water on the basis of source:
 
On the basis of source water may be classified into followings-

1)        RAIN WATER:
  • Rain, collected immediately after recitation, is the purest of all natural water.
  • It may contain traces of gases dissolved out of the atmosphere & possibly an almost infinitely small amount of finely divided solid matter derived from the air.
  • It also contain dissolved or Sulfur DI-oxide or Sulfuric acid, CO2, NH3, NO2 & other by products of industrialization.
  • Suspended impurities present in it, can be filtered by using sand bed.
  • Suitable for boiling, washing & dyeing process.

2)       SURFACE WATER:
  • Surface water may consists of  rain water which has collected from streams, rivers or lakes.
  • This type of water contains organic & inorganic matters which are dissolved in it
  • & also contain suspended impurities.
  • Then the nutrifying bacteria will  in time convert the organic substances into nitrates which are not objectionable in dyeing & printing.
  • Surface waters may receive considerable additions of dissolved mineral salts from shallow springs which feed the streams.
  • It contains Chloride, Sulfate, Carbonate, Bicarbonate of Na, P, Ca & Fe.
  • Not suitable for dyeing & finishing.

3)       SUBSOIL WATER:
  • This type of water is collected from shallow springs & wells which are about 50 ft (15 m) or so deep.
  • It is usually free from suspended impurities because it has been filtered by its passage through the soil. It'll however contain dissolve organic water.
  • Subsoil water is often rich in dissolved Carbon di oxide, a gas abundantly present in the skin of the soil.
  • Subsoil waters are very variable with regard to the impurities which they contain.
  • Not suitable for dyeing & finishing.

4)       DEEP WELL WATER:

  • This type of water is obtained from 500 m below the surface. It is free from organic matters.
  • The soluble impurities in water may be composed of a variety of substances. Soluble organic compounds, ammonium salts, Nitrates & Nitrites of animal; or vegetable origin may be found. If they are present in considerable quantities, the sewage contamination is undesirable for many textile purposes.
  • The presence of salts of Ca or Mg in solution can be most undesirable in many finishing process.

শেয়ার করুন

লেখকঃ

পূর্ববর্তী পোষ্ট
পরবর্তী পোষ্ট