Water hardness | Hardness scales

Water hardness:

Water hardness is a term applied to water devoting a measurement of its p^H and metal salts, content water hardness usually classified in the two groups.

-         Temporary hardness (pressure of Ca and mg bicarbon)

-         Permanent hardness (presence of Ca & Mg sulphate and chloride)

r Hardness Scales:

Description                                       Definition

1⁰ d H (German) Hardness Þ 10⁰ mg Ca0 in 1 liter of water

1⁰ f H (France) Hardness Þ 10⁰ mg CaCo₃ in 1 liter of water

1⁰ e^H (English) Hardness Þ 10⁰ mg CaCo₃ in 0.7 liter of water

1 AH (American) Hardness Þ 1 mg Caco₃ in 1 liter of water

Use of water in textile processing

Water is used extensively throughout textile processing operations. Water is considered as the life time of wet processing in industry because it is the single most used chemical. The amount of H2O used varies (1-2 Lac gallon/ day) depending on pacific processes operated at the mill, equipment used prevailing management philosophy concerning water use. Water is used in the following plants.

(1)  Boiler: Supplying steam for heating and drying

(2)  W.P.T: For desizing, scouring, bleaching, mercerizing dyeing, printing and finishing and washing.