A Review on Ion-exchange Membranes Fouling and Antifouling During Electrodialysis Used in Food Industry: Cleanings and Strategies of Prevention

Abstract

During the last decades, the interest of using ion-exchange membranes (IEMs) in electrodialysis (ED) technologies has emerged in wastewater treatment, drinking water and process water production as well as food industry and more recently in processes of energy conversion and storage. Like in all membrane technologies, the problem of fouling is one of the limitative phenomena of IEM efficiency and lifetime. It mainly leads to an increase in electrical resistance of ED stacks and consequently to increase operating and membrane replacement costs, which directly affects the cost of the final product. In food industry, the composition of the treated solutions and beverages is most often complex and rich in several organic and inorganic compounds which further increases the risks and effects of fouling. Hence, a better knowledge and understanding of IEM fouling phenomena is not only the key to solve the problems and find adequate solutions, but also is one of the main factors driving membrane technology forward. This review is mainly focused on the organic fouling phenomena of IEMs during ED processes in both food and water treatment industries. It principally presents the main cleaning techniques used in industry or experimented at laboratory scale and the recent strategies of fouling prevention.

Electrochemical Methods for Water Purification, Ion Separations, and Energy Conversion

“…The heterogeneous structure of such a membrane also promotes electroconvection and mass transfer by localizing the migration of ions through the conductive parts of the membrane. ,− Because a commercial ED stack may contain 300–500 cell pairs, the conductivity of the membrane will largely determine the overall conductivity of the stack, which in turn influences the energy consumption of the process. Another critical feature of IEMs is their resistance to the formation of deposits (e.g., organic fouling, inorganic scaling), which degrade the performance of the membranes and negatively affect the quality of the water produced. , Much research has therefore been devoted to developing IEMs that have improved antifouling properties, − as discussed in section .…”

A Review on Ion-Exchange Membranes Fouling during Electrodialysis Process in Food Industry, Part 2: Influence on Transport Properties and Electrochemical Characteristics, Cleaning and Its Consequences

“…As mentioned above, the vast majority of liquid media in the food industry are a breeding ground for microorganisms. This fact, together with the need to counteract the growth of colloidal structures inside IEM and on its surface, necessitate regular cleaning of membrane stacks of ED apparatuses [26]. Most often, HCl, NaOH, hypochlorides and other oxidants (peracetic acid, and P3 Active Oxonia ® (Ecolab, Saint Paul, MN, USA) solutions) are used for these purposes [27][28][29][30][31][32][33][34].…”

“…The use of a regenerating solution that contains equal volumes of acetonitril, methanol, isopropyl and distilled water allows an even more complete recovery of phenolic monomeric and polymeric substances (more than 30 items) from CEMs and AEMs that were in contact with wine [26] or cranberry juice [23]. Such recovery is due to the destruction of hydrogen bonds and π-π (stacking) interactions of polyphenols with the material of IEMs, as well as with proteins, amino acids, saccharides and other substances found in juices and wine.…”

“…or animal serum electrodialysis, the decrease in IEC is mainly determined by electrostatic interactions of membranes with highly hydrated colloidal structures that form proteins, carboxylic acids, amino acids, and mineral salts (sodium, potassium, calcium, phosphorus and magnesium). To a greater extent, the IEC of CEMs decreases in acidic solutions, while the IEC of AEMs increases in alkaline and neutral solutions [26,[56][57][58]. These colloidal (network) structures fill both the pores of the ion-exchange material (the walls of which contain polar fixed groups) and the pores with non-charged walls (the reasons for the appearance of these pores were discussed in Section 2), contributing to an increase in water uptake.…”

A Review on Ion-Exchange Membrane Fouling during the Electrodialysis Process in the Food Industry, Part 1: Types, Effects, Characterization Methods, Fouling Mechanisms and Interactions

“…In our present work, we focused on the issues of IEM fouling in the ED industry and it should be noted that this is a subject of common interest to all types of membranes used in all baromembrane [2,19,20] and electromembrane [21][22][23][24] methods. As was defined and explained in our previous review on IEM cleanings and strategies of fouling prevention during ED in the food industry [25], the terms "fouling" and "scaling" designate organic matters and mineral matters, respectively, and the same definition has been adopted in this review.…”