Filtration is the process of passing liquid containing suspended matter through a suitable porous material (filtering medium) to effectively remove the suspended impurities in the liquid. It is the final step in the solid removal process which includes coagulation, Flocculation and sedimentation.
Types of Filters
- Inline filtration – In this process coagulant chemicals are added just prior to the water entering the filtration unit.
- Conventional filtration – It is a process commonly employed in municipal and large water treatments.Here all the pretreatment steps are included
- Direct filtration - It is similar to conventional filtration except that the step of sedimentation is omitted.
Materials used as filter media –
- Quartz sand
- Silica sand
- Anthracite
- Coal
- Garnet etc..
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