Photo-Fenton treatment of water containing natural phenolic pollutants.

Phenolic compounds are known to be present in high concentrations in various types of agro-industrial wastes. As they are highly biorecalcitrant, the possibility of treatment by advanced oxidation processes should be investigated. In this work, six model phenolic compounds (vanillin, protocatechuic acid, syringic acid, p-coumaric acid, gallic acid and L-tyrosine) were chosen for a demonstration of degradation by photo-Fenton reaction, under artificial light in laboratory experiments in Vienna and under sunlight in pilot-plant experiments at the Plataforma Solar de Almería in Spain. All compounds were completely mineralised. No non-degradable intermediates were produced, either in experiments with single substances or in a more complex matrix of a mixture of phenolic compounds. The expected selectivity of the photo-Fenton reaction for aromatic compounds was proven by comparison of the decrease in total organic carbon with the removal of total phenolic content.

[1]  J. Bruneton,et al.  Elementos de Fitoquímica y de farmacognosia , 1991 .

[2]  J. Beltrán-Heredia,et al.  Simultaneous photodegradation and ozonation plus UV radiation of phenolic acids—major pollutants in agro-industrial wastewaters , 1997 .

[3]  V. L. Singleton,et al.  Colorimetry of Total Phenolics with Phosphomolybdic-Phosphotungstic Acid Reagents , 1965, American Journal of Enology and Viticulture.

[4]  J. Box.  Investigation of the Folin-Ciocalteau phenol reagent for the determination of polyphenolic substances in natural waters , 1983 .

[5]  Alberto E. Cassano,et al.  Photocatalysis in water environments using artificial and solar light , 2000 .

[6]  D. Goswami,et al.  Techno-Economic Analysis of Solar Detoxification Systems , 1997 .

[7]  J. Giménez,et al.  Photocatalytic degradation of phenol: Comparison between pilot-plant-scale and laboratory results , 1996 .

[8]  J. L. Garraway,et al.  Plant growth inhibitory activity of extracts of raw and treated pig slurry , 1982 .

[9]  Christian Sattler,et al.  Compound parabolic concentrator technology development to commercial solar detoxification applications , 1999 .

[10]  Cesar Pulgarin,et al.  Accelerated photo-oxidation of concentrated p-coumaric acid in homogeneous solution. Mechanistic studies, intermediates and precursors formed in the dark , 1998 .

[11]  André M. Braun,et al.  Photochemical processes for water treatment , 1993 .

[12]  C. Banks,et al.  The effects of the most important phenolic constituents of olive mill wastewater on batch anaerobic methanogenesis , 1996 .

[13]  Ana M. Amat,et al.  Pyrylium salt-photosensitized degradation of phenolic contaminants derived from cinnamic acid with solar light , 2000 .

[14]  F. González-Vila,et al.  Characterization of wastes from olive and sugarbeet processing industries and effects of their application upon the organic fraction of agricultural soils , 1992 .

[15]  Sixto Malato,et al.  The photo-fenton reaction and the TiO2/UV process for waste water treatment − novel developments , 1999 .

[16]  M. I. Maldonado,et al.  Solar photocatalytic mineralization of commercial pesticides: Oxamyl , 2000 .

[17]  Joseph J. Pignatello,et al.  Degradation of selected pesticide active ingredients and commercial formulations in water by the photo-assisted Fenton reaction , 1999 .

[18]  Ana M. Amat,et al.  Pyrylium salt-photosensitised degradation of phenolic contaminants present in olive oil wastewaters with solar light , 2001 .