Zeolite process for water softening (Permutit process) - Water technology

Description of zeolite process of water softening. It also compares with demineralisation process/ion-exchange process. permutit process. water treatment.
Subscribe for more videos !!!. This method discussed how the cations are removed from the water. It compares zeolite and demineralisation process. It lists the advantages and disadvantages of this method. It describes the types of zeolite.
Zeolite process/Permutit process
You will be able to define zeolite/molecular sieves.
You will be able to mention the types of zeolites.
You will be able to write the principle and describe the zeolite process with a neat diagram.
You will be able to mention the advantages and disadvantages of zeolite process.
Zeolites/Molecular sieves
Zeolites are microporous, hydrated aluminosilicates of sodium, potassium, calcium etc. Hence, they are used as cation-exchangers.
For water softening process hydrated aluminosilicates of sodium is used, which can reversibly exchange its sodium ions with the cations present in the water
Types of zeolites
Natural zeolites – non-porous
Synthetic zeolites – porous – has high ion-exchange capacity
Softening Process
Ion- exchange process (cation-exchange)
The Na+ ions present in the zeolite get exchanged with the cations present in the raw water such as Ca2+, Mg2+ etc.
The water coming out of this column is free from hardness causing ions, but contains sodium salts in it.
ReGeneration of zeolite
When all the exchangeable Na+ present in the zeolite gets exchanged with hardness causing ions such as Ca2+ and Mg2+ present in the water, it gets exhausted and has to be regenerated by treating concentrated NaCl (brine)
Advantages of zeolite water softening process
It removes hardness up to 10ppm.
It does not form any precipitate/sludge.
The maintenance and operation is easy and does not require special skills.
Requires less time for softening.
Equipments are compact and requires less space.
Limitations/Disadvantages of zeolite water softening process
It removes only hardness contributing cations but leaves sodium salts in it. Hence, it cannot be used in high pressure boilers (NaHCO3 and Na2CO3 leads to caustic embrittlement)
It is not suitable if the water is turbid. The colloidal particles present in the water will clog the pores of the zeolite.