Dear sara,

The hydrophobicity of PES typically causes its fouling.

Another material for the membranes, with better hydrophilicity should have better performance.

Hi Sara,

PES  has a relatively high water absorption.

Try other polymers like PEBA.

The typical technique used with such an application would be to use a prefilter followed by the 0.45 micron membrane filter. An appropriate depth filter will provide 10X greater throughput capacity, while protecting the final membrane filter from foulants. The PES membranes are all treated with some type of hydrophicilic agent so that they will wet with water, so binding may play a minor role compared to pore blockage. A 20" cartridge filter is huge compared to your volume. You might consider asking the membrane supplier for their best prefilter recommendation. Pleated glass fibers with a 0.2 to 0.65 micron rating are often used. Depth filters like ZetaPlus are also used. In the end, the less expensive prefilter may be a 10" module and the o.45 micron membrane may be reduced to a small surface area capsule 4-6".

Dear Paola, Abdorrazzagh and Craig. 

Many thanks for your kind and helpful answers. 

Regards,

Sara