UF is a barrier to suspended solids, bacteria, viruses, endotoxins, and other pathogens to produce water with very high purity and low SDI.
A pressure difference is the driving force for the membrane. The pressure difference allows the water to flow through the pores of the membrane. All matter larger than the pores is retained on the surface of the membrane. This process is called pore size exclusion. The membrane is called semi-permeability because it allows water to pass while it retains other substances. The pore size of the membrane determines the size of the particles that are being removed. If the pores are micrometer sized the membrane is called a microfiltration membrane, if the pores are smaller than a tenth of a micrometer the membrane us called an ultrafiltration membrane.
Micro- and Ultrafiltration membrane elements are capable of removing suspended solids, bacteria and larger micro organisms, such as cryptosporidium and giardia. Additionally the ultrafiltration pore size is small enough to reliably remove smaller matter such as viruses, macro molecules and colloidal matter. Dissolved matter, such as e.g. beneficial minerals are not being retained by the membrane elements.
WHAT IT REMOVES
Ground water from a variety of sources, such as ground water, surface water, lake or river water or seawater can be sources for potable water treatment.In some cases, bore holes for collection of ground water that were constructed many decades ago are constructed of bricks. When exposed to ground movement, cracks can develop which allows surface water to enter the bore holes.