Micron filtration is to segregate or separate particulate matter based on the size of the particulate matter. Sewing, screening or surface filtration are also the types of surface filtration based on size of the particulate matter. When the requirement of filtration is less than 0.2 microns, then membrane filtration is also used. In water and waste water treatment, this type of filters are very critical. It acts as a guard filter to further membrane treatment. Micron / membrane filtration also restricts the presence of the organics, bacteria and virus.
Micron Catridge filters restricts, as per its rating, up to 0.2 microns of particulate matter in water. Catridges could be of inert polymer material or of steel. Catridge filters are of two types, absolute filters and nominal filters. Absolute rating filters 99.9% are of particulate matter above the rated microns. Nominal Filter between 80 - 90 % of particulate matter above the rated micron. The major use of Micron Catradige filters is that of pre / guard filter of ultra filteration and Reverse Osmosis. For removal of bacteria and pyrogens for high purity water utilised for pharmaceutical industry.
Ultrafiltration (UF) is a variety of membrane filtration in which hydrostatic pressure forces a liquid against a semi permeable membrane. Suspended solids and solutes of high molecular weight are retained, while water and low molecular weight solutes pass through the membrane.
Ultrafiltration technology produces superior quality water by removing virtually all harmful pathogens and suspended solids. Ultrafiltration membranes are designed for Cross Flow and Dead End filtration. In Cross Flow filtration a portion of the feed passes through the membrane and is called permeate. The rejected materials are flushed away in a stream called the concentrate. Cross Flow membrane filtration uses a high cross flow rate to enhance permeate passage and reduce membrane fouling.
Hollow fibre membranes also have the capability to be backwashed, where filtered water is pushed backwards through the membrane to remove accumulated solids on the membrane surface. Ultrafiltration systems provide flexibility to operate in a range of conditions that can be optimized for a specific water source to reduce operating costs.