What is the process of reverse osmosis?
When a high-pressure pump is used to boost the pressure on the salt side of a reverse osmosis system and push water through a semipermeable RO membrane, almost all of the dissolved salts in the reject stream are left behind in the reject stream (about 95 percent to 99 percent). The amount of pressure required is dependent by the amount of salt contained in the water being used as an input. It is necessary to apply more pressure in order to overcome osmotic pressure when the concentration of the feed water is higher.
Permeate (or product) water is the term used to describe desalinated water that has been demineralized or deionized. The reject (or concentrate) stream is the water stream that contains the concentrated pollutants that did not pass through the reverse osmosis membrane and must be disposed of properly.
With enough pressure applied to water entering the RO membrane to overcome osmotic pressure, the semipermeable membrane allows water molecules to pass while impurities are blocked from passing. This reject stream (also known as the concentrate or brine stream) can be discharged to the drain or recycled through the RO system to save water in certain situations. Typically, the water that passes through the RO membrane has had 95 percent to 99 percent of the dissolved salts removed from it, which is referred to as permeate or product water.
It is important to understand that a RO system uses cross filtration rather than traditional filtration to remove contaminants from water. Conventional filtration involves pollutants being trapped inside the filter media, which is undesirable. After passing through or crossing the filter, the solution leaves through two outlets: one for filtered water, and another for contaminated water. When using cross flow filtration, which helps to prevent pollutants from accumulating on the membrane surface, water is allowed to wash away any particles that have collected on the membrane surface.
Reverse osmosis is a reliable and effective method for producing water that is suited for a wide range of industrial applications that require demineralized or deionized water, such as pharmaceutical manufacturing. An RO system may be utilized after installation to improve the quality of the RO permeate and make it acceptable for high-demanding applications such as pharmaceutical manufacturing by using post-treatment methods such as mixed bed deionization (MBD). Pre-treatment and monitoring of a RO system effectively helps to avoid expensive repairs and unexpected maintenance of the system in the long run. You may expect your RO system to deliver many years of high purity water if it is built properly, maintained properly, and serviced by qualified experts.
Using reverse osmosis correctly may remove up to 99 percent of the feed water’s dissolved salts (ions), particulates (particles and colloids), organics, bacteria and pyrogens (although a RO system should not be relied upon to remove 100 percent of bacteria and viruses).
Including the pharmaceutical industry, RO water is used for a variety of applications such as feed water for boilers, food and beverage production, metal polishing, and semiconductor manufacturing.