CARATTERIZZAZIONE E ATTIVAZIONE ENZIMATICA DI UN REATTORE A MEMBRANA PER LA NANOFILTRAZIONE DEI COMPOSTI FENOLICI

Application of membrane technology to industrial separation processes has significantly increased over the last two decades. Membranes can be used in many different ways, e.g. in concentration or clarification of beverages, for producing drinkable water from sea water, for air purification, and for treating wastewaters. They also find many applications in the medical field, since they are used for blood filtration and for blood oxygenation. Since many of the solution to be filtered containing phenolic derivatives, the treatment of these substances is very important, especially for water purification and industrial purposes (for example in wine and beer industries). Moreover, it is essential for fouling prevention, the most important problem in membrane filtration since causes flux decline and increases the operating costs while decreasing membrane lifetime. On the basis of these issues, the aim of this thesis was to: 1. characterize a mesoporous gamma-Al2O3 membrane by filtering different phenolic compounds (such as phenol, tannins and humic acids), which differ to one another mainly for the molecules dimensions in order to test the membrane selectivity in nanofiltration; 2. exploring the opportunity to modify the membrane, coating it with mesoporous silica in order to obtain a suitable surface for the immobilization of laccase, an enzyme able to catalyze the oxidation of phenol derivatives. An important part of this thesis project, concerning filtrations with a mesoporous gamma-Al2O3 membrane and subsequent modifications, was realized at the Aalborg University, Denmark, as part of an Erasmus exchange program between the University of Torino and the Aalborg University.