Application of pillared raw clay-base catalysts and natural solar radiation for water decontamination by the photo-Fenton process

This study presents a novel application of the heterogeneous solar photo-Fenton process using an iron-pillared clay (Fe-PILC) as a photocatalyst under natural sunlight. The Fe-PILC is characterized by thermogravimetric analysis, EDXRF, SEM and nitrogen adsorption-desorption isotherms. The solar photo-reactor consists of a tubular borosilicate tube with a compound parabolic collector (CPC) and two different materials as reflective material for performance comparison. Phenol is used as model pollutant. The catalytic tests are monitored by the concentration of the pollutant, intermediates and the iron leaching, as well as the accumulated energy during the reaction time. Complementary catalytic tests allowed to establish the influence of parallel processes that could contribute to phenol removal. Experimental data proved that the Fe-PILC is active as heterogenous catalyst in photo-Fenton like processes promoted by natural solar radiation. The catalyst showed good stability in the process and allowed a 99%+ removal of the pollutant and its intermediates. Fenton, photolysis and adsorption do not contribute significantly to phenol removal. Finally, when comparing different reflective materials in the CPC, the aluminium sheet proved to be more efficient than the polyester film metallized with aluminium.