CWC is Africa's most experienced manufacturer of pre-engineered and custom built reverse osmosis systems for the treatment of residential, commercial and industrial water supplies.
All water contains Total Dissolved Solids (TDS). TDS is the measurement by weight of the dissolved materials in a given volume of water. If a material will completely dissolve and is not visible in the water, it is part of the TDS of the water.
Reverse Osmosis helps to lower the TDS content of water, by passing it through a semi-permeable membrane with a pore size of less than 0.0005 microns in diameter. The purified (permeate) water produced by a Reverse Osmosis system is amongst the purest form of treated water available.
Reverse Osmosis can be effectively used for the reduction of Total Dissolved Solids in groundwater, surface water and sea water applications.
Reverse Osmosis is a membrane process that acts as a molecular filter to remove over 99% of all dissolved minerals. Water passes through the membrane while the dissolved and particulate matter is left behind.
As pressure is applied to the concentrated solution, the flow is reversed and water is passed through the membrane from the concentrated side to the dilute side.
Water molecules penetrate the thin layer of the membrane and diffuse through it molecule by molecule. Dissolved salt ions would also diffuse through this layer, except that the solubility of the salt ions in the feed is much less than that of the water. This results in water passing through the membrane more rapidly than salts, causing separation.
The driving force of the reverse osmosis process is driven by both the feed water pressure and the concentration differentials across the membrane surface. For water, the pressure effect is the most important, and for the dissolved ions in the water, the concentration difference is the most important. Therefore, increases in pressure increase the amount of treated water without causing a corresponding increase in waste flow.
The RO process removes most of the dissolved mineral salts, almost all of the particulate matter and most of the dissolved organic compounds.
Reverse Osmosis systems remove substantial amounts of most dissolved minerals (such as salts, metals and other minerals).
Most bacteria and other microbiological contaminants are also removed due to their size in relation to the size of a membrane pore.
Any particulate matter remaining after pre-treatment will also be removed, although RO is not recommended as a filtration process.
The following commonly found minerals are actively reduced by Reverse Osmosis:
CWC manufactures a broad range of Reverse Osmosis systems for almost any application. Specifications below are for our pre-engineered equipment range. For information on larger Reverse Osmosis systems supplied by CWC, visit our custom Reverse Osmosis systems section. For information on our Seawater Desalinators, visit our Seawater Reverse Osmosis section.
|Model||Pure water flow*||Approximate recovery|
*Approximate initial capacity based on properly pretreated feed water of 500 ppm TDS as NaCI, 25°C, Silt Density Index below 3, and 10 bar applied pressure supplying water to atmosphere. Productivity will vary depending on the feed water conditions.
|Inlet Pressure||200-400 kPa|
|Operating Pressure||600-1200 kPa|
|Power||220VAC or 380 V 3-phase|
|Maximum Turbidity||1 NTU|
|Maximum feed chlorine||0 ppm|
|Maximum feed TDS||1000 ppm|
|Maximum iron in feed||0.1 ppm|
On all pre-engineered RO systems, CWC offers a pre-treatment plant as an option. The pre-treatment plant is mounted on a separate free-standing frame, and consists of the following components:
In addition to the pre-treatment system, CWC can add the following pre-treatment and post treatment items to all reverse osmosis systems in the pre-engineered equipment range:
In order to accurately size a reverse osmosis system for commercial or industrial applications, we will need to know the following:
Your local approved CWC distributor can help you calculate your purified water needs, and can arrange for a professional water analysis to be taken. For more information about CWC's reverse osmosis systems and how the RO process can help you in your home or business, contact CWC today.