Water wastage in RO (reverse osmosis) is one of the most discussed problems among water purification system designers and users. With so much time, effort, and money invested in purifying the water for industrial purposes, losing over 30 percent is upsetting, to say the least.
No matter how hard you try, 25 to 30 percent RO water wastage is inevitable. Companies who promise 20 percent or less water wastage most likely design purification systems that don’t last too long. As the system is forced to work harder, you may need to replace membranes more often, negating the money-saving efforts of reducing the wastage.
At Wychwood Water Systems, we adhere to the golden standard of 70 percent pure water recovery, which is a good figure to aim for. If for some reason your RO purification system is providing a less efficient output, there are ways to reduce the water wastage.
Watching The Membrane
Clogged membranes are among the most common reasons for reduced purification output. RO membranes can last for years as long as they are cleaned on a regular basis. A clean membrane is an insurance against increased water wastage in RO.
The average membrane lifespan is about three to five years. Monitoring the membrane quality is essential to improving the output. As soon as you notice that the output drops more than 10 -15 percent below target parameters, it’s time to clean the membrane.
Investing In A High-Quality Water Purification System
The better an initial investment you make in a water purification system, the less water wastage you’ll experience. High-quality purification systems have an optimised filtration stage configuration, which reduces the water wastage.
Feed Water Pre-treatment
Pre-treating the wastewater is vital to reducing wastage. Removing free chlorine, calcium, magnesium, and other contaminants ensures a quality RO output. Failing to pre-treat the water for these contaminants results in membrane clogging and degrading. This eventually leads to reduced output and frequent membrane replacement.
Water purification systems are delicate. However, they can work for many years with the proper maintenance. Most systems require professional recalibration once every 6 months. Membrane cleaning may be needed more often depending on the exploitation rate.
The water pump needs to be checked as well. Inaccurate water pump performance and leaks can lead to water wastage in RO.
Maintaining Peak Performance
In order to keep the RO purification systems in a top-notch condition and increase the water output, you can do the following:
- Install GAC (Granular Activated Carbon) to remove the contaminants using absorption over the carbon method.
- Install a duplex meter to control the release of water softeners.
- Install 5-micron absolute rated depth filters to reduce the particle and fouling index (replace them every 3 months).
- Install adequately sized feed pumps for your throughput volume (places less pressure on membranes).
Another smart way to reduce RO water wastage is to use effluent for other purposes in your facility that don’t require pure water.
Water System Design Specialists
At Wychwood Water Systems, we specialise in designing, installing, and maintaining water purification systems. For more information about reducing water wastage in RO systems, take a look at our Industrial Water Purification Guide e-book, which can be accessed here.