Evaluation of fouling potential of nanofiltration membranes based on the dynamic contact angle measurements

In this work the studies were performed on the intensity of fouling of the membrane NF90 and NF270 depending on the value of dynamic contact angle, previously determined for these membrane. The NF membranes were used for the separation of broth obtained during the fermentation of glycerol by Lactobacilluscasei bacteria. The measurements of dynamic contact angle were carried out using the Wilhelmy plate method. Taped membranes samples (support layer to support layer), wetted for 2 days in deionized water prior to testing, were used to study the contact angle of top layer and its organic fouling. Using deionized water; the contact angle values equal to 27-30o and 53-57o for NF270 and NF90, respectively, were obtained. As a consequence of adsorption of organic compound on the membrane surfaces, the contact angle obtained for both fouled membranes was about 55-56o, and this value was closer to the contact angle of non-fouled NF90 membrane. Therefore, the NF90 membrane was more resistant to organic fouling during the separation of broth.