Catalytic activity of magnetic compounds for degradation of organic pollutants under UV/H2O2 Processes

ARIADNA FLORES; KARINA NESPRIAS; PAULA VITALE; ADRIANA CAÑIZO; NORA EYLER

Foz do Iguacu

Conferencia; 12° Conferencia Latinoamericana de Físicoquimica orgánica; 2013

CLAFCO

In recent years, an urgent need has arisen to preserve the enviroment by removing chemical pollutants originated in different human activities. Water pollution is a serious problem as pollutants are accumulated and/or transported in streams, rivers, lakes, dams, affecting human?s health. Industrial discharge of effluents containing dyes influences the natural aspect of rivers and has a negative impact upon aquatic life causing serious environmental problems1-3. The present work aims to study the degradation /discoloration of aqueous solution of the organic dye Rhodamine B (RhB) and phenol by heterogeneous photocatalysis in the presence of H2O2 as a ?green oxidant?. Magnetic copper ferrospinels, steel wool and magnetic portion of Puyehue volcanic ash were used as photocatalysts. The effect of different operating parameters such as the amount of photocatalyst, H2O2 concentration, light intensity, radiation source, and reutilization of the photocatalyst on successive dye discoloration experiments was also investigated. An optimum concentration of H2O2 and catalyst dosage was found for the RhB and fenol degradation reactions. Both pollutants in different experimental condition follow a pseudo first order kinetic law. The discoloration of RhB was higher than 95% in 5 min, showing that the degradation of this dye is strongly promoted by the magnetic copper ferrospinels and steel wool, but not by volcanic ash. On the other hand, the phenol has been degraded by copper ferrospinels (91.5%), steel wool (97%) and magnetic portion of volcanic ash (95 %) in 160 minutes. Samples with phenol and some of its degradation products (p-hydroquinone, maleic acid) were analyzed by liquid chromatography (HPLC) with UV detector at 270 nm, on a reverse phase column. Copper ferrospinels, steel wool and magnetic portion of volcanic ashes showed catalytic activity on the degradation of RhB and phenol under UV/ H2O2 advanced oxidation processes. A synergistic effect on the reactions studied was demonstrated when combining photochemical technology, a magnetic catalyst and hydrogen peroxide. This method of purification of water does not generate secondary pollution and involves materials that can be recycled and easily used on an industrial scale. In addition, the application of magnetic separation can be considered as a quick and effective technique to solve environmental problems caused by wastewater discharge. References 1.-AlHamedi FH, Rauf MA, Ashref SS, (2009), Desalination, 239:159-66. 2.- Bergamini R, Azevedo BM, Raddi de Araújo EB (2009), Chem Eng J, 149:215-20. 3.- Nguyen TD, Phan NH, Do MH, Ngo KT. (2011), J Hazard Mater 185:653-61. Aknowledgements: This work was financially by Facultad de Ingeniería and SECAT UNCPBA, Argentina.