The basic ro filtration process works by pushing water through a semi-permeable membrane under pressure greater than the natural osmotic pressure. During this process, almost all dissolved salts and other contaminants are left behind in the concentrate stream. This process can reduce turbidity, organics, bacteria, pyrogens, and other contaminants from feed water.

The “good” water that emerges from the RO system is known as permeate or product water and can be used in a wide variety of applications. The waste stream is known as the concentrate, reject, or brine and it contains all of the contaminants that cannot pass through the membrane. The concentrate can be discarded or used for other processes such as wastewater treatment, evaporation, or industrial cooling.

How Reverse Osmosis Filtration Works: Everything You Need to Know

A pretreatment filter should be installed before the RO membrane to protect it from contamination and reduce microbial growth. This is especially important when using the system with chlorinated water or other oxidizers, as they will corrode the membrane and shorten its life. Flow rates and recovery are also very important for the efficiency of an RO system. A high recovery rate will result in less water sent to drain as concentrate and more permeate water being saved for use.

A properly designed and maintained ro system will produce clean, quality water for many years. However, improper design and operation can lead to premature membrane failure and costly unscheduled maintenance. To minimize these problems, it is important to understand the causes of membrane fouling and scale formation. Providing the correct pretreatment and regular monitoring can greatly reduce these problems.