Understanding and Managing Increased TDS from Deionisation Resin

Deionisation (DI) is a widely used water purification method that employs ion-exchange resin to remove impurities. However, one common challenge faced by users of deionisation systems is an unexpected increase in Total Dissolved Solids (TDS) levels. In this blog post, we will explore the reasons behind the increase in TDS from deionization resin and discuss effective strategies to manage and mitigate this issue.

Why Does TDS from Deionization Resin Increase?

1. Exhausted Resin:

Over time, the ion-exchange resin used in deionisation systems becomes exhausted due to the accumulation of impurities. As the resin reaches its capacity to exchange ions, it becomes less effective in removing contaminants, leading to an increase in TDS levels. This issue typically occurs when the resin bed is not replaced at the appropriate intervals.

2. Contaminated Source Water:

Another factor that can contribute to the rise in TDS is the quality of the source water. If the water being treated contains high levels of dissolved solids, such as minerals, salts, or organic compounds, the resin bed may become overwhelmed and fail to remove all of the impurities. This can result in an increase in TDS readings even after the water has passed through the deionization system. Osmotics Reverse Osmosis systems employ robust pre-filtration therefore contaminated water is more likely due to exhausted pre-filtration resulting from poor system maintenance. 

3. Poor System Maintenance:

Insufficient system maintenance can also contribute to an increase in TDS levels. Inadequate pre-filtration, improper resin rinsing, or irregular resin regeneration can lead to resin fouling or channeling, reducing the resin's efficiency in removing dissolved solids and causing TDS levels to rise.

Managing Increased TDS from Deionisation Resin:

1. Regular Resin Replacement:

To maintain optimal performance, it is crucial to replace the deionisation resin bed at recommended intervals. This process involves removing accumulated impurities and restoring the resin's ion-exchange capacity. Consult the manufacturer's guidelines for specific instructions on when and how to replace the resin in your deionization system.

2. Effective Pre-Filtration:

Implementing proper pre-filtration measures is essential for preventing contaminants from reaching the resin bed. Utilize appropriate pre-filters to remove particulate matter, sediments, and chlorine/chloramines, if present in the source water. This helps protect the resin and ensures efficient TDS removal.

3. Monitor Source Water Quality:

Regularly monitor the quality of the source water to identify any changes in TDS levels. If the source water's TDS is consistently high, consider alternative water treatment methods or explore additional filtration steps to reduce the load on the deionisation system.

4. Maintain System Integrity:

Regularly inspect and maintain the deionisation system to ensure it operates at its optimum capacity. This includes checking for leaks, verifying proper resin bed alignment, and performing routine resin bed rinsing to remove any trapped contaminants.

5. Quality Testing:

Perform periodic quality testing of the deionized water using a reliable TDS meter. By monitoring the TDS levels of the treated water, you can detect any deviations from the expected range and take corrective action promptly.

Conclusion:

Managing TDS levels from deionisation resin is essential to maintain the performance and effectiveness of your water purification system. By understanding the factors that contribute to increased TDS and implementing appropriate maintenance practices, you can ensure that your deionization system consistently delivers high-quality, low TDS water. Regular resin regeneration, effective pre-filtration, source water monitoring, and system maintenance are key steps in addressing and mitigating TDS issues, resulting in optimal performance and longer resin life for your deionisation system.