Electrodialysis

Modeling and applications of electrodialysis in the food and biotechnology industry

This activity initially focused on the modeling and application of electrodialysis (ED) to the recovery of fermentation products of food interest. Sodium acetate, sodium lactate and sodium propionate, salts of monoprotic organic acids widely used in the food industry, were studied. By using a modeling approach based on mass balances, phenomenological expressions of mass fluxes as a function of the driving forces, and description of polarization phenomena, it was possible to develop a unified model to describe the behavior of ED plants for the recovery of these salts. This approach was awarded the Lerici Prize in 2005 as the best doctoral thesis in Food Science and Technology. 

More recently, interest has focused on developing approaches to experimentation that allow the estimation of ED model parameters while minimizing the resources required (e.g., the number of desalination experiments to be performed, the duration, the amount of salt in the solution to be desalted). In particular, the model-based approach to optimal design of experiments was found useful.  

Further applications of electrodialysis included the removal of arsenic for the potabilization of water. 

Recently we investigated the deacidification of fruit juices by electrodialysis with monopolar membranes showing that the organic anion transport through the anionic membrane can be explained by using the theory of transport of anpholytes which involves proton generation at the membrane-solution interface.