Q. Define filtration. What are the objects of filtration?
Filtration is a process of removing particulate and bacterial impurities which could not be removed in earlier processes, from water by passing it through a porous medium. It is an important stage in the purification of water.
Objects of Filtration:
To remove suspended, colloidal and other impurities which impart turbidity to water and untrapped by previous processes.
To reduce bacterial load by about 90$\%$ .
To produce sparkling and aesthetically attractive water.
To reduce odour and colour imparted by fine colouring matter, by arresting them in filter media.
To alter the chemical characteristics of water.