How to Maintain an Osmosis Drinking Water System for Optimal Performance？

How well you take care of a business or industrial reverse osmosis drinking water system directly affects how consistently pure the water is and how cheap it is to run. Many big factories in Asia, South America, and Africa trust their reverse osmosis systems to work every day. These factories make food and drinks, medicines, electronics, and water for cities. Maintenance saves your investment, keeps the water quality at the right level, and avoids costly downtime. In real life, a well-kept brackish water or tap water RO plant can reject 99% of the salt, recover 55-70% of the water, and have a membrane life of 4–7 years. If you don't take care of the same system, the flux will drop quickly, the membrane will need to be replaced often, and energy will be wasted, which can make running costs 30–40% higher. Following a strict maintenance plan that includes daily checks, planned part replacements, and regular professional service is what makes the difference.

Understanding the Core Components of Your Osmosis Drinking Water System

Pre-filtration: The First Line of Defense

One of the first steps in any reverse osmosis device is pre-filtration. This step is very important for keeping the RO membrane safe. In this step, a 5-micron sediment filter is used to get rid of rust, sand, and silt that are stuck in the water. The next step is an activated carbon filter, which gets rid of chlorine, chloramines, and organic garbage. Without this wall, these things would hurt the membrane in a way that can't be fixed. There would be a lot of early fouls, and the system would not work as well. Get rid of these bad things early on in the pre-filtration process to make the system last longer and keep the quality of the percolate fixed. It's important to keep an eye on how much the pressure drops through these screens. If you see it going up, you need to get new ones right away to keep the next steps safe.

High-Pressure Pump and RO Membranes: The Core Separation Process

For uses that need 15–25 bar of pressure for salty water, the high-pressure pump drives the osmosis drinking water system by raising the pressure of the feed water. The compressed stream is then sent to the RO membrane modules, which are usually 8-inch polyamide elements wound in a coil. Here is where the separation really happens: dissolved ions, organics, and bacteria are thrown out, and the removal rates are often over 99%. The barrier is only partly porous, so clean water called permeate can pass through it. Reject is the name for concentrated salt that is sent away as trash. There may be problems with the osmosis drinking water system that need to be fixed right away if the pump pressure drops or the product water conductivity slowly goes up. These problems could be membrane scaling, fouling, or pump wear.

Post-Treatment and Operational Metrics: Ensuring Water Purity and Efficiency

We treat the permeate after it goes through the membranes to make sure it stays safe and doesn't change quality. Changing the pH could be one way to keep the pipes from rusting, and UV cleaning could be another way to get rid of any germs that are still there. One more thing that is important to know is the rejection rate and the repair rate. Recovery rate (usually between 55% and 70% in Morui systems) shows how much of the feed water is turned into product. Higher recovery lowers trash but increases the chance of scale. On the other hand, the rejection rate shows how well the system can get rid of dissolved solids. This is important for meeting standards like GB 19298 or WHO guidelines, especially when making water for bottling that hasn't been treated in any other way.

Routine Maintenance Tasks That Deliver the Biggest Return

Operators who follow these proven routines see membrane life extend to 6+ years and energy consumption stay within 2.8-3.2 kWh/m³.

Daily and Weekly Checks (approximately 15 minutes per day)

For example, the feed pressure, the change in pressure between each membrane step, the permeate flow rate, and the final water conductivity are all things that are measured every day. One important part of this check is keeping an eye out for certain signs of poor performance. A drop of 10% in the measured permeate flow or a rise of 15% in the difference pressure are both clear signs that something needs to be fixed or looked into right away. Every day, you should also check the pre-filter pressure drop and write it down. When the pressure difference (ΔP) reaches the safe range of 1.0 to 1.2 bar, the cartridge filters should be changed right away to keep the next parts safe. Check to see if the high-pressure pump is making any odd sounds or moving around too much. This will help you make sure it works right and avoid problems that need fixing right away.

Monthly and Quarterly Scheduled Tasks

There are some things that need to be changed regularly, but not too often. At least once every one to three months, the 5-micron silt pre-filters should be changed in the osmosis drinking water system. Every three to six months, you should change the carbon block filters in the osmosis drinking water system. They get rid of chlorine and organic matter. It all depends on how good the feed water is, especially how much chlorine it has and how dense the silt is (SDI). It is also important to start a low-pressure clean-in-place (CIP) process with an alkaline cleaning solution if the adjusted permeate flow drops by 10-15% in the osmosis drinking water system. This will help get rid of the smell. Systems that are used to make medicines, electronics, or baby food need to be put through tougher tests in the osmosis drinking water system. Checking the Total Dissolved Solids (TDS) of the product water every hour is one way to make sure the osmosis drinking water system stays clean.

Annual Deep Maintenance

A full chemical cleaning process is used during the annual deep clean, which is the most thorough maintenance task. This is usually done when the standardized flow drops by more than 15% or when salt passing goes up by more than 10%. A citric acid cycle is often the first step in the process. This breaks down metal scales. Next, a high-pH chemical cleaning removes organic gunk and biofilms. Many facilities plan this kind of intense repair to happen during their yearly production shutdowns so that they don't have to deal with too many problems. In the end, reverse osmosis (RO) membranes need to be changed when their salt rejection rate regularly drops below 97%, even after being cleaned with chemicals several times, or as a preventative step after five to seven years of normal use. This is to make sure the system works well and the water quality is good.

Advanced Care and When to Call the Experts

Some problems require experience and specialized equipment that only an OEM or qualified service provider can deliver.

Membrane Autopsy and Fouling Analysis

When normal Cleaning-in-Place (CIP) methods don't work to fix membrane performance, it is strongly suggested that a full laboratory autopsy of a sample element be done. This in-depth study uses microscopic examination, chemical tests, and the definition of foulants to correctly find the root cause, such as chemical breakdown, chronic biological fouling, or permanent silica scaling. The results give important information about problems that affect the whole system, which lets the whole plant take specific steps to fix them. With accurate analysis, workers can change preparation, find the best cleaning methods, and stop damage from happening again. This extends the life of the membrane and makes it more reliable in use.

Signs You Need Professional Intervention Immediately

In the next 24 hours, the permeate conductivity of the osmosis drinking water system suddenly goes up by more than 50 µS/cm; the system recovery rate drops by more than 10% below what was planned; the high-pressure pump runs at an unusually high current; or you see reddish-brown spots on the membrane surfaces. You need to get help right away. These signs usually mean that there is severe scaling, fouling, or mechanical damage in the osmosis drinking water system that can't be fixed by cleaning. If you don't get help right away, the membrane in the osmosis drinking water system could get damaged in a way that can't be fixed. This could cause production delays that cost a lot of money and system problems that affect many parts.

Global Emergency Service and Support

Guangdong Morui Environmental Technology Co., Ltd. offers rapid and reliable support with 20 full-time RO engineers and 14 branch offices worldwide. Our team has worked on more than 800 industrial plants in Asia, South America, and Africa, so they know what they're doing. In an emergency, we can be ready to go within 48 hours with real new membranes made in our own plant. This makes sure that clients who depend on reverse osmosis systems in tough settings have minimal downtime, uniform system performance, and long-term operating stability.

FAQ

1. How often should RO membranes be replaced in a drinking water plant?

Reverse osmosis (RO) membranes in brackish water systems usually last between 5 and 7 years if they are properly maintained and used in normal situations. The feed water should have an SDI that is constantly less than 3. The main sign that it's time to replace something is a clear and permanent drop in performance, especially when the salt rejection rate drops below 97% even after proper chemical cleaning. Other things that might mean the membrane needs to be replaced sooner are a big drop in normalized permeate flow that can't be recovered or a steady rise in normalized pressure drop across the membrane elements. It is important to keep an eye on these performance indicators on a regular basis in order to find the best repair time, make sure the system works well, and get good water in the end.

2. Can I use generic filters instead of OEM cartridges?

Even though common replacement filters might seem like a good deal, they often make operations less efficient and could even damage RO membranes further down the line. These non-OEM refills often have a higher pressure drop, which can make the whole system use more energy. More importantly, they might not have uniform quality control, which could lead to membrane thickening, channeling, or media movement happening too soon. Morui, on the other hand, tests each and every batch of its pre-filter cartridges carefully in our own lab. This careful process makes sure that the water treatment system works perfectly, with accurate micron rates and the ability to hold dirt. This protects the RO membranes as much as possible and keeps the system reliable over time.

3. What is the best way to store spare RO membranes?

To keep spare RO membranes in good shape while they are being stored, it is important to keep them in their original, sealed packaging and keep the temperature stable between 5°C and 25°C. They should also be kept away from direct sunlight and freezing temperatures. For keeping times longer than 6 months, an extra step is needed to keep the elements safe: they need to be taken out of their packaging and fully submerged in a protected solution, which is usually a solution with a 1% concentration of sodium bisulfite. This answer stops cellular progress by acting as a biostat. The storage container should be closed up, and the solution for keeping things fresh should be checked and maybe even replaced every so often until the membranes are ready to use.

Industrial Osmosis Drinking Water System Manufacturer | Morui

Guangdong Morui Environmental Technology Co., Ltd. supplies complete 10-1000 m³/h reverse osmosis drinking water system plants for potable water production. We manufacture our own membranes, assemble skids in our factories, and provide one-stop installation, commissioning, spare parts, and lifetime service support across Asia, South America, and Africa.

Contact our senior sales engineer Benson Lai directly at benson@guangdongmorui.com for technical specifications, pricing, and site visit arrangements. Most inquiries receive a detailed proposal within 24 hours.

References

1. American Water Works Association. Reverse Osmosis and Nanofiltration, Manual of Water Supply Practices – M46 (2nd Edition).

2. World Health Organization. Guidelines for Drinking-water Quality, 4th Edition incorporating the 1st addendum.

3. U.S. EPA. Membrane Filtration Guidance Manual, 2005.

4. International Desalination Association. IDA Desalination Yearbook 2022-2023.

5. Astm International. ASTM D4194 – Standard Test Methods for Operating Characteristics of Reverse Osmosis and Nanofiltration Devices.

6. Journal of Membrane Science. Volume 625, May 2023, Article 119152 – Long-term performance of industrial RO plants.