We have recently had a lot of demand for ion exchange column testing to both demonstrate resin performance and reduce risk in tricky water treatment applications.
Over the last few years, the EPA have been requesting extensive water treatment plants be developed to ensure environmental compliance of discharge water from industrial sites, garbage tips (also known as landfill leachate), tunnelling projects as well as mining. This involves the removal of a wide range of contaminants that can impact the natural environment and humans including PFAS, chromium, nitrate, phosphorus, polyaromatic hydrocarbons(BTEX), arsenic, heavy metals and other carcinogens.
Due to the health risks, environmental sensitivity and historical pollution, we are being asked to treat our waters to a higher and higher level.
Ion exchange as well as GAC adsorption processes are critical in treating these waters but often poorly understood, especially at the ultra-pure discharge levels required. Pilot testing can be crucial to demonstrate plant performance in reaching these targets with competing interferences and fluctuation in water quality.
Reasons for Column Testing
There are several reasons that you may want to undertake either laboratory or pilot ion exchange testing including:
- Leakage level testing: The leakage level is the amount of a contaminant that passes into the effluent water during normal operation. For ultrapure applications (whether they are for environmental discharge or for feed to a power station) these are really important. Many things will impact the leakage including feed concentrations, competition with different ions, the pH (and changes) and the condition of the resin. Understanding these inferences can be critical in avoiding headaches in the future.
- Breakthrough Curve Analysis: Involves plotting the concentration of ions in the effluent against the volume of effluent. The point at which the resin becomes saturated and the effluent ion concentration starts to increase is known as the breakthrough point. This helps in determining the capacity of the column and the need for regeneration.
- Product Comparison: Comparing the performance of different ion exchange resins or columns under similar conditions is valuable in finding the best performing and best priced product for your facility. It can also help derisk changing to a new supplier who may have a better price or shorter lead-time. Performance metrics such as ion removal efficiency, capacity, regeneration frequency, and operational costs are compared. This helps in selecting the most suitable product for specific water treatment needs.
- Water Treatability Studies: Assessing how well the ion exchange column can treat different types of water is critical in many applications but especially environmental processes with many competing ions. Samples of different water sources are processed through the ion exchange column and the treated water is analysed for residual contaminants, and removal effectiveness.
- De-risking Resin Change: This involves testing new resins before fully integrating them into the system to ensure that new resins perform well and don’t negatively impact the water treatment process. Small-scale tests are a useful way to gain confidence with a new resin under expected operating conditions. Based on these results, a decision is made on whether to implement the new resin system-wide. This approach minimizes risks associated with changing resins and ensures a smooth transition.
- Processes Demonstration: This involves piloting new treatment processes within the ion exchange column system to demonstrate their effectiveness. This can also involve other processes such as reverse osmosis. The performance of these processes is monitored through various metrics such as ion removal efficiency, treatment capacity, and operational feasibility.
Recent Case study: Hydrocarbon contaminant removal
A recent example was from a client with a critical BTEX removal process. They were facing a number of issues with their plant but in particular they needed to regenerate their resin every 30 minutes which consumed a signficant amount of steam. We identified three alternative resins and our modeling predicted that with careful operation we should be able to extend this to 24h or more. However, given the cost of the resin replacement and importance of the treatment, we needed to make sure that the plant was going to perform. We then conducted a column test to compare three resins and select the best performing (and most cost-effective resin). This involved two rounds of testing, the first stress-testing an alternative resin across a range of 6 different source waters and the second round was to qualify the two additional resins. This allowed site to meet environmental compliance requirements but also find a cheaper resin that could be sourced much quicker and with confidence. Our breakthrough curve analysis showed that the new resins should be able to reduce the regeneration frequency by 20-40x which will yield a massive energy saving.
Resin supply – backed by science!
Membrane Works are not only Australia’s premium resin testing laboratory but we are also able to supply you with the best performing resins at the best price for your application. We provide not only the resin but the support with an in-depth scientific understanding of both the ion exchange process and your treatment system.
Do you need support piloting a new treatment process. Contact us today to discuss how we can help make this a reality.