Title: Optimizing Membrane Cleaning: The Impact of Temperature, pH, Time and Chemical Selection on Cleaning Efficacy
Discuss membrane cleaning optimization parameters, and how they are implicated in cleaning. A case study will be presented that demonstrates the process of said optimization and the impacts each factor has on the determination of an appropriate protocol to recover performance.
Membrane fouling and scaling are two of the primary issues membrane-based systems must contend with to ensure efficient water treatment. Membrane scaling can be solved with appropriate antiscalant selection, while fouling can be mitigated by good system design. As membrane systems are called on to treat more challenging water sources, and existing systems are asked to increase production, both of these challenges become even more difficult. Inevitably most systems will foul requiring cleaning to reverse the losses in membrane performance. Unfortunately, membrane cleaning is an expensive and time-consuming procedure. To mitigate these costs, membrane cleanings are often put off until operational costs become excessive, or equipment limits are reached. This can lead to exceedingly tenacious foulants that standard protocols cannot clean effectively. Insufficient cleaning will lead to more rapid fouling in the future, increasing the required cleaning frequency. It is therefore important that an optimal protocol for each membrane system be determined. Cleaning performance is significantly impacted by the specifics of the foulants in question, cleaning chemical selection, cleaning pH, temperature, and exposure time. All of these factors need to be weighed against the CIP system design and operational constraints. A case study will be presented to demonstrate this optimization process. The case study describes the evaluation of the membrane fouling, identifying the cause of the performance decline, demonstration of the impacts each factor has on the determination of an appropriate protocol to recover performance.
Joshua Utter, Technical Applications Manager at AWC, holds a bachelor’s of science in Chemistry with a minor in mathematics from Jacksonville University in Jacksonville, FL. He has been performing membrane autopsies on RO/NF and MF/UF membranes at American Water Chemicals since 2014. Joshua has 7 years of experience in evaluating membranes through element performance testing as well flat sheet performance testing, cleaning studies, mechanical integrity testing, dye testing, and visual inspections. He has also accumulated experience in Fourier Transform Infra-Red (FTIR) spectroscopy, Raman microscopy, Goniometry and various other instruments used for foulant analysis.
Joshua provides on-site support to customers during membrane cleaning, and assists customers with troubleshooting, data normalization and other necessary technical tasks for proper monitoring of plant performance.