EMI Twente provides a membrane autopsy service to help customers determine cause of failure or fouling of membranes. Additionally, cleaning recommendations can be provided. We perform autopsies on reverse osmosis membranes, nanofiltration membranes, ultrafiltration modules and more. Our team of membrane experts will analyse the membranes to determine proper chemical treatments and to provide preventative measures for the future.


Scaling and fouling are the biggest challenges in membrane operations, having a serious negative effect on membrane performance. Typically, fouling will result in lower permeance and/or higher operational pressure leading to lower process efficiencies or loss of production capacity. In addition, membranes might get mechanically damaged by inproper operation with lower retention as a result. Identifying these causes will lead to higher uptime, lower cleaning frequency and more consistent operation.


Pre-autopsy testing
Upon arrival, the module will be inspected visually and pictures are taken of the exterior, and reported.

After exposing the insides of the membrane element, the membrane envelope and spacers are inspected visually and pictures are taken of both parts. Several DIN A4 sized samples are taken from the membrane for further testing, and stored at 3°C.

Initial performance parameters
A piece of membrane is be tested for initial performance parameters. Normalized data (flux, salt rejection) is collected and compared to the manufacterer’s specification to judge how well the element performs.

Foulant screening
The membrane is screened for fouling, based on customer application and feed type. This can include (but is not limited to) SEM(-EDS) analysis to determine coverage and morphology of inorganic scaling.

Low retention root cause analysis
Low retention can be a result of mechanical damaging or result of oxidation of the polyamide composite by oxidants such as halogens, peroxides and ozone. The cause of reduced retention can be elucidated through dye testing and oxidation tests, combined with an analysis of the customers process.

Based on the type of foulant(s) that are identified during autopsy, we can provide input on which type of cleaning agent to use to keep membrane performance optimal.

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Senior Research assistant