Since the advent of membrane technology applications in commercial and industrial water desalination and purification plants utilizing RO, NF, UF & MF processes, membrane manufacturers, system suppliers and end-users alike have been facing two major problems: how to adequately and reliably monitor membrane system performance and how to detect membrane fouling and scaling development in real time and before significant or irreversible loss of performance and equipment occurs. The current industry-standard membrane performance analysis and evaluation is based on normalization of operating data in accordance with ASTM D-4516 standard method.
What’s Wrong with ASTM Performance Trending?
This analytical technique was originally developed by the industry’s pioneer and early leader, DuPont, and represents only the membrane performance trend from a membrane manufacturer’s point of view based on in-house test data and not on reallife site-specific plant’s design, operating parameters and other dynamics. By definition, trending requires a statistically valid, and reasonably large amount of operating data records plotted over a long period of time to establish a definite trend. Field experience at a large variety of membrane plants around the world in the past 20 years shows that it is virtually impossible to detect the early development of membrane fouling in a system simply by monitoring a long-term trending analysis. By then, the fouling practically becomes too significant (i.e., uncleanable) and often causing irreversible loss in performance and element damage. This is largely due to the fact that fouling is cumulative in nature and builds up over a long period of time, unless it is already too severe from the start, before it starts noticeably exhibiting its physical effects at the plant.
The Fouling Monitor (FM)
To address the critical need of RO, NF and other membrane plant operators and owners to detect and measure membrane fouling or scaling development as early as it starts to occur and to monitor the real performance of their membrane systems in realtime, MASAR Technologies, Inc., has developed an innovative and practical new approach – the Silent Alarm. The new approach was discovered after many years of closely monitoring and trending the flux decline performance of a large RO plant 2 with a biofouling history that exhibited itself suddenly after the first 2 years of operation.
Silent Alarm software optimizes membrane plants