What industries use reverse osmosis?

An Overview of Reverse Osmosis (RO)

Reverse osmosis, also referred to as RO and desalination is a process whereby fresh water with unwanted contaminants, or sea water is forced through a filter/membrane at high pressure. As the water passes through a partially permeable membrane; any ions, salt, bacteria, unwanted molecules and large particles are removed. This process is commonly installed on marine vessels as a means of purification to produce potable water (drinking water) from sea water.

The core process of desalination is the Reverse Osmosis Process. It consists of a high-pressure pump followed by an Energy Recovery device and the Reverse Osmosis Membranes. Before entering the seawater reverse osmosis membranes, clarified seawater is pressurized by the High-Pressure Pump typically between 55 and 85 bars, depending on the temperature and the salinity of the water.

Industrial Applications of Reverse Osmosis (RO)

Manufacturing and industrial plants use high volumes of water as part of their everyday processes not only for production but for the cooling of products and equipment. It’s also used for cleaning and storing specialist products in order to maintain the expected levels of health and safety. Due to the high volumes needed, water scarcity is often a problem for those within the industrial sector. Installing water treatment facilities into an industrial plant can help drive down the environmental damage and cost caused by wastewater. It also prevents the issue of water scarcity, giving you more control over your water. Reverse osmosis units are highly beneficial to the industrial sector. The cleaning of water makes it reusable; this then limits the amount of water contamination.

Dependent on your raw water, many different industrial water filtration systems can be used to remove impurities, solids and chemicals. Reverse osmosis is becoming an increasingly popular choice due to the fact it can remove more than most other systems. There are several industrial applications for reverse osmosis as following:

Municipal Water Purification:

Municipal water is used for both domestic and commercial applications. The need for quality water goes way beyond cooking and washing purposes in industry. The food and beverage industry seeks quality control so the taste of a soda or recipe is consistent regardless of the location.  Both the pharmaceutical and chemical industries are highly affected by the bad quality of water due to the presence of microbial contamination, chemical residue, salinity, etc. Commercial reverse osmosis systems are heavily utilized in purifying municipal water to ensure good quality water.

Desalination of Seawater:

The only source of water for many populated areas come from oceans and seas with salts levels up to 35,000 mg/l. Marine industrial applications, off-shore drilling, maritime transport as well as cruise ships also rely on this high salinity water. The continuous use of water containing high levels of salts can damage marine equipment and are unfit for consumption. Thus, to remove the salt content from seawater, the marine industries install high pressure commercial reverse osmosis systems with specialized membranes. It helps in desalination along with the reduction of chemical and bacterial contamination.

Desalination of Brackish Water:

Combined fresh and salt water is considered brackish water which consists of 1,000 to 15,000 mg/L of dissolved salts. Whereas, for industrial and potable water applications, the WHO suggests water with salinity lesser than 500mg/L for potable drinking water. The reverse osmosis (RO) technique is employed for the desalination of brackish water as well.

Boiler Feed Water:

Industrial boilers are sensitive to hard water. The use of hard water under high temperature causes problems like scaling, thermal transfer deficiencies, increased down-time for cleaning, and life-cycle reduction of the boiler vessel. Therefore, only softened water should supply and be fed to the boiler system. To achieve such a goal, industries like mechanical, chemical, pharmaceutical, and lumber/pulp industries, utilize reverse osmosis systems for pre-boiling water treatment/conditioning.

Wastewater Treatment:

Water treatment industries have adopted reverse osmosis as one of the water purification techniques. Reverse osmosis is usually employed as the final process for the reduction of chemical, bacterial, and dissolved impurities. Reverse osmosis (RO) systems are a part of the tertiary water treatment in the wastewater industries. Similarly, industrial wastewater is pre-treated by reverse osmosis (RO) system before disposal. Industrial gray water treatment, blackwater treatment, etc. utilizes commercial reverse osmosis systems.

Spot-free Rinse:

In industrial manufacturing, equipment cleaning, and even in commercial applications like car washing, surface rinsing, etc. often salt-free water is required. Otherwise, the hard water causes scaling, hard surface spots, and even surface bleaching due to the presence of chemicals or magnesium and calcium salts found in it. Therefore, the rinsing water is purified using reverse osmosis systems to avoid equipment damage and increase the product-lifecycle.

Can RO Be Used Commercially?

Water filtration systems such as RO are being used more commercially due to the success they have in the industrial process.

The process of installing an RO system for commercial use mirrors that for industrial use as each system is bespoke to the water issue.

Conclusion

Reverse osmosis uses cutting edge modern membrane technology rather than chemicals to treat and manage wastewater. In areas of Japan and California, where there are extreme water limitations, RO plants are being used to treat water that comes from the biological treatment of domestic water, with the water treated by RO being used to refill groundwater resources.