Pollutants abatement in aqueous solutions with geopolymer catalysts: A photo fenton case.

Environmental pollution is a serious threat to human health and the natural environment, and it has aroused widespread concern. One of the most effective processes in the removal of pollutants from wastewater is the Fenton reaction. This process is based on the production of highly reactive •OH radicals due to the rapid reaction between Iron ions and hydrogen peroxide under acidic conditions. The hydroxyl radical has a high oxidation potential of E°(•OH/H2O) = 2.8 V/SHE at acidic pH, so they are extremely reactive and non-selective oxidizing agent towards organic contaminants in wastewater. In order to avoid the drawbacks of a standard Fenton reaction, a photo Fenton reaction has been tested working at neutral pH in water in the removal of refractory pollutants. For the first time, a heterogeneous system was experimented, impregnating porous metakaolin-based geopolymers, obtained by using hydrogen peroxide and vegetable oil in different ratios, as foaming agents, with iron working as photocatalyst. The dirty wastewater as scrubber water (SCRW) and liquid fraction of digestate (LFD) were tested obtaining 40-90% abatement of Total Carbon Content.