Reverse Osmosis
| Ultrafiltration (UF) Technology |
| Ultrafiltration
is used in water filtration systems to remove bacteria, algae, cysts,
parasites and microbial contaminants. The UltraPure range of water filters uses hollow fibre ultrafiltration (UF) membrane technology. The hollow fibre UF membranes are made from polymeric material and resemble straight lengths of noodles which are hollow on the inside.  On
the surface are very tiny holes or pores which run over the entire
length of the noodles. These pores, which are not visible to the naked
eye, can only be seen using high powered special microscopes. The
tightly controlled microscopic pores range from 0.01 to 0.1 micron in
size. For comparison, the full-stop at the end of this sentence is 500
microns.The pores have the ability to stop the passage of particles, turbidity and pathogens such as bacteria, algae, cysts and parasites but allow water and natural, healthy essential minerals such as calcium, magnesium and potassium to flow through. The result is a consistent supply of high quality treated water. The UltraPure range of water filters use UF membrane with outside-in or inside-out configurations depending on specific applications. They require no electricity.
The UF membranes used in the UltraPure range of water filters are the same membranes used extensively for disaster-relief aid. In 2004, they were deployed to tsunami relief efforts in Thailand and Aceh and more recently to cyclone relief efforts in Myanmar. |
| Reverse Osmosis (RO) Technology |
| Reverse
Osmosis (RO) is recognized by
experts
as the best technology available to remove the widest
spectrum of contaminants found in drinking water
(e.g. bacteria, virus,
flouride,
arsenic, dissolved heavy metals, nitrate, microbial
contaminants, salts). Reverse osmosis has also been identified by US EPA as the best available technology(BAT) and Small System Compliance Technology (SSCT) for radiation such as uranium, radium, gross alpha, and beta particles and photon emitters. It can remove up to 99 percent of these radionuclides; as well as many other contaminants (e.g., arsenic, nitrate, and microbial contaminants). ref US EPA, Radionuclides in Drinking Water. ref Forbes, How to remove radioactive iodine 131 from drinking water RO is the process by which water molecules are forced through a 0.0001 micron semi-permeable membrane by water pressure. Long sheets of the membrane are ingeniously sandwiched together and rolled up around a hollow central tube in a spiral fashion. This rolled-up configuration is commonly referred to as a spiral wound membrane or module. RO membranes are available in different sizes for processing different quantities of water. Typically, a RO membrane for home water treatment is as small as 2" diameter and 10" long (as illustrated below),  while one for commercial & industrial use may be 4" diameter and 40" long (as illustrated below).  RO membrane alone in general cannot handle the typical load of particulate contaminants and dissolved solids without prefiltration. Often, a well designed systems employ multiple stages of prefiltration, tailored to the application, including melt-blown, sediment and carbon pre-filter. This is to provide sufficient protection for the RO membranes and prolong its life. Some systems include post treatment like granular activated carbon (GAC). All RO systems will have a reject flow to purge the dissolved solids from the RO membrane, prolonging the membrane life. Some systems comes with a pump to improve the flow rate. In this case, electrical power is required. The quality of RO water is easily measured using a TDS meter or test pen. It is measured in PPM (parts per million) of total dissolved solids (TDS) in the water. A typical home RO system is illustrated below.  while a commercial & industrial is illustrated below.  |
