Water in the textile industry and major water consuming section in the textile industry. Source of water and desirable water parameters.

1. Water, Hardness, Treatment
WPE-I
Md. Abdul Hannan
Assoc. Prof.

2. Outline
• Water in Textile Industry.
• Major water consuming sectors in textile industry.
• Water Used For 100 Kg Cotton.
• Sources of Water.
• Important parameters for water to be used in
textile wet processing.
• Desirable Water Quality Parameters for Textile
Wet Processing.
• Disadvantages of Hard or Unsuitable water usage
in textile processing.

3. Water in Textile Industry
• The textile industry is the 3rd largest consumer of water
in the world.
• Wet processing engineering is one of the major
streams in textile chemical processing.
• Water is the most common and vital solvent for wet
processing.
• Water containing impurities that are not useful, so it
would affect our textile wet process and cause a defect
in the form of shade variation, unevenness and
damaging of textile material.
• Therefore, the quality of water should be necessarily
maintained for better performance.

4. Major water consuming sectors in
textile industry
Sizing/De-sizing
Scouring
Bleaching
Dyeing
Printing
Finishing
Washing
Mercerization

5. Total water consumed during wet
processing
Process Percent water consumed
Pretreatment 38%
Dyeing 16%
Printing 8%
Boiler 14%
Other Uses 24%

6. Water Used For 100 Kg
Cotton(approx.)
Process
• Sizing
• Desizing
• Kierring
• Mercersing
• Scouring
• Bleaching
• Direct
• Vat
• Reactive
Water in litre
• 700
• 1500
• 1100
• 4500
• 3000
• 1000
• 5000
• 15000
• 5000

7. Sources of Water
Water Source pH Total
Hardness
(ppm)
Salinity Total
Dissolved
Solid(mg/L)
Lake Water 7.2 900 0.1 272
Sea Water 7.7-8.0 1000 42.3 38.5
Spring Water 5.5 700 0.01 89
Irrigation
Water
6.0 125 0.001 125
Rain Water 5 50 0.3 122

8. Important parameters for water to be used in textile wet
processing
• Color
• Turbidity
• pH value
• Alkalinity
• Acidity
• Salinity Content
• Total Dissolved
Solids(TDS)
• Total Suspended
Solids(TSS)
• Specific Conductivity
• Total Hardness
• Temperature
• Iron Content

9. Color
• Color normally indicates the presence of soluble
and suspended matter , which affects the textile
wet processing .
• The color of water is measured in terms of Hazen
units, by comparing it with a color of a standard
solution.
Hazen Unit: The color produced by dissolving 1
ppm platinum in the form of chloroplatinic acid , in
the presence of 2 ppm cobalt chloride.

10. Turbidity
• Turbidity is caused by the scattering of light by suspended particles
which may be organic or inorganic in nature.
• The turbidity of water is measured against a standard solution
having a standard turbidity value 1000 units.
pH Value
• In all textile processes in which aqueous solutions are used,
balancing the pH of the solution is primary.
• The pH of a textile is logically defined in terms of the hydrogen ions
concentration of the water present in the cloth.

11. Acidity
• The alkalinity is due to the presence of bicarbonates ,
carbonates or hydroxides.
• Alkalinity is divided into caustic alkalinity ( above pH 8.2) and
total alkalinity above pH 4.5.( Bicarbonate and caustic alkalinity).
Alkalinity
• Most natural waters are buffered by a CO2 / HCO3 system.
• Carbonic acid is not fully neutralized until a pH of 8.2 and will not
depress pH below 4.5.
• CO2 acidity is in the pH range of 8.2 to 4.5 , mineral acidity due to
industrial waste is below pH 4.5.

12. Salinity Content
• Salinity is a measure of content of salts in soil or water.
• Saline water is used in the dyeing process, when saline water,
cloth and dye are placed in the dyeing machine. The salt
dissolved in water drives the dye out of the water and in to the
cloth.
• The cloth is then removed and water containing the dissolved
salt is left behind.
Total Dissolved Solids (TDS)
• TDS comprise of inorganic salts and small amounts of organic matter
that is dissolve in water. The TDS is measured in ppm (mg/ltr).
• TDS affects quality and efficiency in many processes from boiler
water to the dye house.
• A TDS reading of 65-150 ppm is considered appropriate for the dye
house.

13. Total Suspended Solids (TSS)
• The suspended solids are discrete particles
which are insoluble in water .
• These can be removed by filtration and are
also measured in ppm.
Specific Conductivity
• Specific conductivity is the ability of water to conduct electricity.
• Conductivity in water is affected by presence of inorganic
dissolved salts such as chloride nitrate etc.

14. Total Hardness
• Hardness is caused by compounds of calcium
and magnesium, and a variety of other metals.
Types of Hardness:
• Temporary Hardness: When only bicarbonate
salts of Ca and Mg are present.
• Permanent Hardness: When sulphate chloride
and nitrate salts of Ca and Mg are present.

15. Iron Content
• Iron can occur in water in a number of forms.
• Water turns red or brown due to presence of
ferrous iron called as clear-water iron.
• Water turns red or yellow due to presence of
ferric iron called as red-water iron.
• So we should take care that there should be
minimum iron content in the water used for
textile wet processing.

16. Desirable Water Quality Parameters
for Textile Wet Processing
• pH →6.5-7.5
• TDS → 300 ppm
• Color → 5 Hazen
No.
• Total Hardness
→ 30 ppm
• Turbidity → nil
• Suspended
Solids → nil
• Copper →0.01
ppm
• Manganese → 0.05
ppm
• Aluminium → 0.2 ppm
• Chloride →150 ppm
• Sulphate →150 ppm
• Nitrate → nil
• Iron →0.01 ppm
• Chromium →0.01
ppm

17. Disadvantages of Hard or Unsuitable
water usage in textile processing
• Formation of hard soaps with calcium and magnesium ions,
which results into shade change.
• Carbonates of calcium and magnesium precipitate iron and
aluminum mordant and substantive cotton dyestuffs.
• Some dyes got duller and even scum formation happens in
the hard water.
• The metal ion impurities such as iron and copper , is a
problem in the peroxide bleaching baths, iron is responsible
for reducing the brightness of many dyes and is also
objectionable in the washing off operations.
• Hard water is responsible for scale formation in the boilers.
• If temporary hardness is high, the soft scales are formed
which causes corrosion.