2- WATER Summary of the chapter 2: WATER Enter
DEFINITION: Chemically, water is a molecule composed of two hydrogen atoms and one oxygen atom. Is a liquid compound that is colourless, odourless and tasteless
evaporation condensation precipitation Surface runoff NATURAL CYCLE OF WATER
On the way , the water carries along, dissolves and incorporates substances in its path. The composition part of the salts and minerals it encounters in its path COMPOSITION:
WATER QUALITY FOR LAUNDERING The water it is in this environment that the detergent processes are carried out. On the quality and quantity the water will depend a part of the result of the wash. OPTIMAL WATER QUALITY for the laundry: APPERANCE Clean, no debris in suspension, colourless ORGANIC MATTER Potable water with no organic matter remains HARDNESS Ideally 4-5ºHF (40-50 ppm)< 20ºHF (100 ppm CO3Ca) ALKALINITY PA = 0ºHFTAC = < 25º HF Ph 7.0 – 8.0 SALINITY < 1000 ppm IRON < 0,1 ppm MANGANESE < 0,05 mg/l
APPEARANCE: ORGANIC MATTER: The water should be clean and transparent without suspended solids, colourless. The clothes act as filter and retains everything in the water contains. These come from the descomposing of living matter contained in the water.The water must be of hygienic quality, but it can contaminate the textiles.
HARDNESS: Water hardness is caused by the presence in the water of soluble calcium and magnesium salts. To certain temperature calcium and magnesium precipitate to form whitish deposits on the machine and on the linen. The water dilutes the calcareous rocks in its path, so calcium concentracions vary in each area.
PrecipitationIt forms calcareous depositsIncrustation in linen and machineryThe lime-scale reduces the termal conductivity by precipitating of heater Decrease washing efficiencyIt combine with the soaps to form insolubles saltsIt combine with alkalinity to form calcium soaps PROBLEMS caused by the HARDENESS in the laundry: