When should I do an autopsy?
Over time the performance of all membrane processes degrade. Performance loss may happen gradually or in the case of an unexpected event, a rapid decrease may occur. Membrane performance loss can happen for a range of reasons, which include:
- Change of the feed water characteristics (composition and/or quantity) at the beginning of a treatment train
- A change or failure in the upstream processes (for example a change in chemical addition or operating parameters)
- The gradual build up of fouling not removed through normal cleaning procedures.
- General ageing of the membrane
When you are operating a membrane facility there are a number of typical operating parameters which will indicate a loss in performance. They are:
- Reduced product flow
- Poor product water quality (e.g. increased salt passage or higher filtrate turbidity)
- Increased operating pressures
- Higher pressure drops along elements
- Decreased filtration time between cleaning or maintenance procedures
In all of the above cases a normal process audit or review may be able to identify the root cause of your issue. If an audit doesn’t provide you actionable recommendations to bring your membrane system back to a suitable operating state, a membrane autopsy may provide additional information to help resolve your problem.
Other reasons for an autopsy
Over 90% of autopsy’s are conducted due to a loss of system performance. However, there are a number of other situations in which you may consider conducting a membrane autopsy, including:
- After pilot testing, and prior to scale up, to increase awareness of potential operational issues (e.g. fouling tendency of the feed water) and to inform on appropriate technology selection
- At the conclusion of a commissioning period for a new installation. This may be part of the initial contract and is often performed by, or on behalf of the membrane manufacturer.
- To check on the performance of your chemical addition (i.e. anti-scalants, biocides or cleaning chemicals)
- Towards the nominal end of your membranes expected life. At this point an autopsy process can assess the current condition of the membrane and provide a cost benefit analysis as to whether to replace them now or continue to operate with them.
I think I need an autopsy, what now?
If your membrane performance has declined and you think an autopsy will help solve your issue, contact us. We will be able to walk you though the process. If your membranes are still under warranty, also contact your supplier as well, as an autopsy may be covered.
If an autopsy is recommended, our experienced staff will help you identify which modules your should remove for testing and identify system information and water quality data needed to get the most out of the process.