Bacteria is one of the worst enemies of all water purification systems. The key to keeping it away is proper prevention. In case the prevention methods fail and bacteria makes its way into the system, it’s vital to get rid of it as soon as possible. Otherwise, it starts spreading and creating a biofilm, a protection layer which is extremely hard to remove.

Lack of proper system maintenance and disinfection leads to bacteria growth. When bacteria appears, the whole system needs to be shut down, which leads to expensive downtime.

Getting rid of bacteria fast is the key to getting the system back online as soon as possible. Let’s discuss the steps for effective water purification bacteria removal.

1) Understanding Reverse Osmosis

Reverse Osmosis is the most common method of removing bacteria in water purification systems. It uses a membrane which filters organic compounds out of the water. The best RO systems operate at 70 % efficiency.

RO catches the majority of bacteria and viruses which can’t physically pass through the membrane. Taking proper care of the membrane is highly important for the water purity. If the membrane gets dirty or damaged, it stops functioning properly.

2) Pre-Treatment

Before the reverse osmosis system starts working, it’s important to pre-treat the water. Free chlorine, calcium and magnesium can damage the membrane, making bacteria removal ineffective. Eventually, the degraded membrane will let the bacteria through, contaminating the system.

Reverse osmosis water purification systems are equipped with pre-filters. The most common are sediment and carbon filters. They deal with silt, dirt, and numerous membrane clogging and damaging sediments as well as chlorine.

3) Passing Through Membrane

The semipermeable reverse osmosis membrane is the heart of the system. Feed water is delivered to the membrane after going through the pre-filter. It is helpful to have a good flow of water across the membrane to allow it separate well and rinse contaminants away to drain effectively. Incorrectly sized and/or underworked RO membranes can harbour contaminants if off-line for long periods of time.

4) Post Membrane Purification

After going through the membrane, the water can be treated by other technologies such as UV irradiation and sub-micron filtration. If supplying a ringmain with multiple points-of-use, an appropriately sized ringmain pump to provide a sufficient level of recirculation and turbulence is essential. It may also be prudent to install a chiller system in the ringmain to prevent temperature build-up.

5) Regular Maintenance

Regular maintenance of the reverse osmosis system is the key to effective water purification and bacteria removal. Membrane cleaning and system disinfections have to be performed on a regular basis. Expert maintenance can keep the system working flawlessly for many years.

Other Methods Of Bacteria Removal

Besides reverse osmosis, there are other ways to remove bacteria from the industrial water.

• Chemical treatment – The addition of chemicals reduces the chances of bacteria formation and spreading.
• Nanofiltration – This method works similarly to reverse osmosis, removing most of viruses and bacteria from water. However, the membrane has a pore size of 0.001 microns as opposed to RO’s 0.0001 microns.
• UV purification – The ultraviolet light energy alters the DNA of bacteria cells stopping them from reproducing. The kill rate of such disinfection is 99.99%.

Effective bacteria removal can make a difference between excellent system function and breakdowns. At Wychwood, we design water purification systems to prevent bacterial growth. For more information, please download our free Industrial Water Purification Guide.