Reverse osmosis (RO) is a water treatment process that removes contaminants from unfiltered water, or treated filtered water containing undesirable constituents or contaminants such as sediment, chlorine taste and odor, heavy metals, lead, etc. when pressure forces it through a semipermeable membrane. Water flows from the high concentration side (more contaminants) of the RO membrane to the low concentration side (fewer contaminants) to provide clean drinking water. The fresh water produced is called the permeate. The concentrated water left over is called the waste or brine. A semipermeable membrane has small pores that block contaminants but allows water molecules to flow through. Figure 1 demonstrates the working principle of reverse osmosis systems.
Figure 1 – Principle of Reverse Osmosis Systems (Source: ESP WATER PRODUCTS)
A RO system has a filter with a pore size of approximately 0.0001 micro which can remove contaminants as small as a molecule. It is considered an optimum treatment for removal of a wide range of common chemical contaminants in drinking water such as sodium, chloride, chromium, arsenic, copper, lead, fluoride, radium, radon, uranium, calcium, magnesium, potassium, nitrate, and phosphorus Reverse Osmosis Systems have a very high effectiveness in removing protozoa (for example, Cryptosporidium, Giardia), bacteria (for example, Campylobacter, Salmonella, Shigella, E. coli), and viruses (for example, Enteric, Hepatitis A, Norovirus, Rotavirus). RO systems are commonly used for reduction of total dissolved solids and suspended particles in drinking water. RO systems can vary depending upon the volume of water to be treated, contaminants to be removed, etc. However, most RO systems have a few common components as listed below:
MAINTENANCE AND REPLACEMENT OF RO MEMBRANES
A well-maintained RO system can last up to 10 to 15 years depending upon usage and type of contaminants treated. Some of the basic maintenance guidelines include:
Pay attention to the filter change schedule in the RO system’s owner’s manual. The RO system may have three, four or five stages, so know exactly what filters are in each stage of the system (per the owner’s manual) and pay careful attention to when each filter is due for replacement.
Failure to change out filters per their replacement schedule can not only cause damage to the system but will also cause a decrease in water production. Thus, if there is a noticeable decrease in water flow from the RO faucet, that may be an indication that the filters have reached the end of their life span.
Additionally, the following are the three main guidelines for replacing RO membranes
Reverse osmosis filtration system is one of the most extensive methods of filtration. It removes a broad range of contaminants such as total dissolved solids (TDS), chlorine taste and odor, organic compounds, sediment, and cysts, and a broad spectrum of drinking water contaminants. Sani Water is one of the exclusive consultants and experts on providing installation and maintenance services for whole house reverse osmosis systems.