Water Hardness Name : MAZADUL HASAN SHESHIR ID: 2010000400008 Batch: 13th Batch (Session 2009-2013) Department: Wet Processing Technology Email: mazadulhasan@yahoo.com Blog: www. Textilelab.blogspot.com Southeast University Department of Textile Engineering PREPARED BY ©right Generally soaps create foam in water, but in present of some materials the foam creation is reduced and need more soap for producing foam, and this condition of water is called water hardness. The presence of Calcium, Magnesium salt i.e. bicarbonates, sulphates, chloride in water is called causes of hardness of water. The water which contains these salts is called hard water. Hard water does not easily form lather with soap as the salt of Calcium and Magnesium react with soap to form insoluble organic salts. CaSO4 + 2RCOONa → (RCOO)2Ca ↓ + Na2SO4 MgSO4 + 2RCOONa → (RCOO)2Mg ↓ + Na2SO4 WATER HARDNESS WATER The major concern for any kind of wet process industry is ‘Water’ because it is the quality of water which determines the quality of dyeing. Water quality generally vary in different areas, also depends on the level or height of water level beneath the ground. In Narayangonj water level is around 130-140 ft but Knit Concern dyeing water is lifted from about 600 ft deep by submergible pumps. Quality of Water found in the raw water here – total Hardness – 250-300 ppm pH – 8-9 TDS – 2000-3000 ppm SECTION HARDNESS IRON CONTENT TDS pH Knit dyeing - <70 0.02 ppm <500 6.5-7 Yarn dyeing - <50 0.02 ppm <500 6.5-7 Quality of water required for Dyeing: WATER Reasons of water hardness 1. Temporary hardness: Ca(HCO3)2, Mg(HCO3)2, Fe(HCO3)2 2. Permanent hardness: CaCl2, CaSO4, Ca(NO3)2, MgCl2, MgSO4, Mg(NO3)2 TYPES/ CLASSIFICATION OF HARDNESS 1. Temporary hardness. 2. Permanent hardness. [...]... above types of water, soft water with total hardness 5-8 0 is suitable for dyeing In another cases like scouring we may use hard water Water hardness can also be noted as below: Upto 50 PPM → Water is very soft 50 to 100 PPM → Water is moderately soft 100 to 150 PPM → Water is slightly hard 200 to 300 PPM → Water is hard Above 300 PPM → Water is very hard STANDARD/ QUALITY OF DYE HOUSE WATER STANDARD... 17.90 American Hardness = 1.450 eH = 1.790 fH 10dH = 10 mg/ litre CaO = 7.4 mg/ litre MgO = 22.5 mg/ litre Ca(HCO3)2 = 30 mg/ litre NaHCO3 Among the above the hardness which is expressed by the amount of NaHCO3 present in water is called alkaline hardness CLASSIFICATION OF WATER ACCORDING TO HARDNESS: DESCRIPTION TOTAL HARDNESS Very soft 0-4 0 Soft 5-8 0 Mild 9-1 40 Fairy hard 1 5-1 80 Hard 1 9-3 00 Very hard... ESTIMATION OF WATER HARDNESS ESTIMATION OF WATER HARDNESS Water hardness can be determined by the following 2 methods1 By titration with standard soap solution: In this method total hardness/ permanent hardness can be measured 2 By titration with HCl: In this method temporary hardness can be measured ESTIMATION OF TEMPORARY HARDNESS BY TITRATION BY TITRATION WITH HCL: For determining temporary hardness. .. the required amount of 0.1N HCl for titration in cc by – 2.5 gives French hardness 1.78 gives English hardness 1.4 gives German hardness Permanent hardness can be found by deducting the temporary hardness from total hardness i.e Permanent hardness = Total hardness – Temporary hardness Classification of water according to hardness Hardness rating ppm of CaCO3 (grains/US gallon) of CaCO3 Soft 0 to . present in water is called alkaline hardness. CLASSIFICATION OF WATER ACCORDING TO HARDNESS: DESCRIPTION TOTAL HARDNESS Very soft 0-4 0 Soft 5-8 0 Mild 9-1 40 Fairy hard 1 5-1 80 Hard 1 9-3 00 Very hard. of water, soft water with total hardness 5-8 0 is suitable for dyeing. In another cases like scouring we may use hard water. Water hardness can also be noted as below: Upto 50 PPM → Water is. found in the raw water here – total Hardness – 25 0-3 00 ppm pH – 8-9 TDS – 200 0-3 000 ppm SECTION HARDNESS IRON CONTENT TDS pH Knit dyeing - <70 0.02 ppm <500 6. 5-7 Yarn dyeing - <50 0.02