Title: Development and use of a novel method for in line characterisation of fouling layers electrokinetics properties and for fouling monitoring


Journal: Journal of membrane science

Authors: Benoit Teychene, Patrick Loulergue, Christelle Guigui*, Corinne Cabassud


Universit? de Toulouse ; INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France

INRA, UMR792 Ing?nierie des Syst?mes biologiques et des Proc?d?s, F-31400 Toulouse France

The original and creativity of paper: The paper validates the new protocol to investigate the growth of cake layer on membrane surface during filtration process using electrical potential measurements.    

Summary:

This study aimed to examine the electrokinetic properties of a cake layer during its formation as a new fouling indicator. This study presented both theoretical analysis and application. For the application, the new measurement method at constant pressure and used during the filtration has to be developed, validated, and applied in link with filtration operating parameters (e.g., operation time and transmembrane pressure). 

The new protocol to monitor fouling was divided into three phases:

-    The first phase:  electrostatic charges inside the membrane sample were stabilized electrostatic charges inside the membrane sample.
-    The second phase: the membrane fouling is performed and also both permeate flux and electrical potential were measured in continuous during the filtration.
-    The third phase: electrostatic properties of the virgin and fouled membrane were obtained during this phase. 

The method to validate this new protocol can be done by the comparison of values obtained by classical streaming potential measurements and values obtained by this new protocol. Note that the electrostatic charges of new approach was measured by using monodispersed and negatively charged submicron latex particles. 

The results showed that an electrical potential variation during fouling is straight related to the transmembrane pressure and varies as the fouling rate for a constant deposited mass of particles on the membrane. However, an increasing of the mass of particle deposited mass influences electrical potential amplitude at constant pressure. Additionally, this new method can be provided the dynamic information on electrokinetic behavior during membrane fouling. Since the electrostatic charges are stabilized during cake layer formation, thus all electrical potential variation against permeate flux can be plotted in a triangle limited by classical streaming potential values. This obtained information could be really useful in the preparation of dynamic membrane that is usually prepared by modification of the membrane surface. 

Application & further study: The new method for fouling monitoring is very meaningful for the others who interested about fouling mechanism. This can be an inspiration to develop the better approach for fouling monitoring.


By Monruedee Moonkhum
Email: moon@gist.ac.kr