22-03-2014, 03:07 PM
ION-EXCHANGE PROCESS AND TREATMENT OF WATER FOR DOMESTIC USE
[attachment=60425]
SEDIMENTATION
1.Sedimentation is the process by which the force of gravity acts on particles heavier than water and causes them to move downwards and settle.
2.The time required for sedimentation depends upon the weight , size and shape of the particles and the viscosity and fractional resistance of water
3.Water is kept in sedimentation tanks from 4 to 12 hours. Generally , only 70% of the suspended matter settles down by plain sedimentation.
COAGULATION
1.Coagulation reactions are complicated but a simplified explanation can be that the salt hydrolyses and produces a floc of the hydroxide, e.g., Al(OH)3 and Fe(OH)3
2. Generally about 95% of the suspended matter is removed by coagulation.
3.Pottash alum and ferric alum are the most wide used coagulants
FILTERATION
1.Filtration may be defined as ‘the process of passing a liquid containing suspended matter through a suitable porous material in such a manner as to effectively remove the suspended matter from the liquid.
2.Generally ,water is filtered after sedimentation and coagulation.
3.Filtration removes the suspended matter and to some extent bacteria.
STERILIZATION AND DISINFECTION
After filtration it becomes necessary to destroy or make inactive the residual bacteria and to prevent their further growth. This is achieved by sterilization and disinfection.
1.Chlorination is mainly used for killing disease – producing organisms.
2.Bleching powder is convenient for use on smaller scales. Its disinfecting action is due to the chlorine made available by it.
[attachment=60425]
SEDIMENTATION
1.Sedimentation is the process by which the force of gravity acts on particles heavier than water and causes them to move downwards and settle.
2.The time required for sedimentation depends upon the weight , size and shape of the particles and the viscosity and fractional resistance of water
3.Water is kept in sedimentation tanks from 4 to 12 hours. Generally , only 70% of the suspended matter settles down by plain sedimentation.
COAGULATION
1.Coagulation reactions are complicated but a simplified explanation can be that the salt hydrolyses and produces a floc of the hydroxide, e.g., Al(OH)3 and Fe(OH)3
2. Generally about 95% of the suspended matter is removed by coagulation.
3.Pottash alum and ferric alum are the most wide used coagulants
FILTERATION
1.Filtration may be defined as ‘the process of passing a liquid containing suspended matter through a suitable porous material in such a manner as to effectively remove the suspended matter from the liquid.
2.Generally ,water is filtered after sedimentation and coagulation.
3.Filtration removes the suspended matter and to some extent bacteria.
STERILIZATION AND DISINFECTION
After filtration it becomes necessary to destroy or make inactive the residual bacteria and to prevent their further growth. This is achieved by sterilization and disinfection.
1.Chlorination is mainly used for killing disease – producing organisms.
2.Bleching powder is convenient for use on smaller scales. Its disinfecting action is due to the chlorine made available by it.