Since, Thousands of years filtration has been used to reduce the level of dirt, rust,suspended matter and other impurities from water. This is achieved by passing thedirty input water (influent) through a filter media. As the water passes through themedia, the impurities are held in the filter media material. Depending on theimpurity and the media, several different physical and chemical mechanisms areactive in removing impurities from the water. Some of the equipment used toemploy these mechanisms has changed dramatically over time. Other systems, suchas depth filters, have undergone very little change.
The fundamental physical and chemical mechanisms that occur during filtration havebecome better understood over the years. These advances have allowed watertreatment specialists to optimize the removal of impurities from the water. Filtrationsystems remove particulate matter and, because of the large surface area of filtermedia, they also can be used to drive chemical reactions that result in the removal ofseveral contaminants. The following mechanisms for the removal of impurities by agiven media are discussed in the next section.
• Occlusion - removal due to the impurity’s particle size.
• Adsorption - removal due to the impurity’s adherence to the media.
• Reduction - removal of free residual chlorine through conversion tochloride ions in the presence of activated carbon media.
• Oxidation - removal of iron and manganese using oxidation, precipitationand filtration in the presence of greensand media.
After a review of filtration theory, the operation and design of the following process units is discussed.
• Gravity filter - removal of suspended solids and turbidity.
• Pressure Sand filter - removal of suspended solids and turbidity.
• Multi Grade filter - removal of suspended solids and turbidity.
• Multi-media filter - removal of suspended solids and turbidity.
• Activated Carbon filter - removal of free residual chlorine.
• Iron Removal filter - removal of iron and manganese.
• Micron Bag filter - removal of iron and manganese.
• Micron Cartridge filter - removal of suspended solids.
Fluid Sep Technologies, offers the best tailor made solutions for pre-treatment, pre-filtration, protective filtration for membrane systems in term of above filters.