Water decontamination by heterogeneous photo-Fenton processes over iron, iron minerals and iron-modified clays

DE LEON, M.A.; SERGIO, M.; BUSSI, J.; ORTIZ DEL PLATA, G.; CASSANO, A.E.; ALFANO, O.M.

SUSTAINABLE ENERGY DEVELOPMENTS, Series

CRC Press/Balkema

Año: 2012;

The development of new clean technologies that reduce effluent pollution or mitigate the inefficiency of conventional effluent treatment methods constitutes a significant contribution to the fulfillment of sustainable development goals. Large-scale effluent treatment plants rely on a number of physical and/or physicochemical methods, such as filtration, reverse osmosis and activated carbon adsorption, chemical methods, such as chlorination, ozonisation and thermal oxidation, and biological methods. However, the removal of barely biodegradable and/or highly toxic pollutants —i.e., harmful even in extremely small doses— by the currently used methods is often highly inefficient and/or costly. Current laboratory- and pilot-scale studies are aimed at developing non-conventional, more effective methods for the efficacious treatment of pesticides, heavy metals, chlorinated hydrocarbons, dyes disinfectants, and antibiotics, among other pharmaceutical and biomedical contaminants.Among the non-conventional methods, Advanced Oxidation Techniques (AOT) are based on the high oxidizing power of hydroxyl radicals (HO•) and their rapid, non-selective reaction capacity (Legrini et al. 1993, Ameta et al. 2012). In view of the short half-life of hydroxyl radicals, they are generated in situ by different oxidizing agents (H2O2, O3, O2) that may be either present in or expressly added to the reaction medium. AOTs enable the efficient conversion of organic matter into stable inorganic compounds like water, carbon dioxide and salts (mineralization). AOTs are particularly useful for destroying biologically toxic or non-degradable organic compounds, such as aromatics, pesticides, petroleum constituents, and volatile species in waste water.