Showing papers by "F. Javier Benitez published in 1997"

Simultaneous photodegradation and ozonation plus UV radiation of phenolic acids—major pollutants in agro-industrial wastewaters

Abstract: The degradation of four phenolic acids by single UV radiation and by the advanced oxidation process constituted by the combination of ozone and UV radiation has been conducted. The phenolic acids, caffeic, p-coumaric, syringic and vanillic, were selected because they are major pollutants which are present in wastewaters from the production of olive oil and from wine distillery plants. In the single photochemical oxidation, the influence of the operating variables is established and the quantum yields for each individual reaction are evaluated by means of a competitive kinetic method. In the combined ozone/UV radiation process, the generation of the hydroxyl radicals improves the degradation rate in comparison to the single oxidations performed: ozonation and UV photodegradation. ©1997 SCI

Treatments of wastewaters from olive oil mills by uv radiation and by combined ozone‐UV radiation

Abstract: The chemical oxidation of the organic matter in olive mill wastewaters by the advanced oxidation process ozone plus UV radiation is studied to evaluate the increase in degradation in relation to ozonation alone. Also, the effect of the UV radiation alone on the oxidation is established. The destruction of the organic material was followed by the disappearance of the chemical oxygen demand (COD), the total aromatic compounds and the total phenolics. An approximate kinetic study is developed, the apparent kinetic constants with respect to the phenolic compounds being determined in both processes, the single photochemical and the combined ozone‐UV radiation.

Chemical pretreatment by ozone of wastewaters from olive oil mills

Abstract: Chemical oxidation by ozone of the wastewaters from the olive oil process is carried out to remove organic matter present in those wastes. The degradation process was followed by measuring the chemical oxygen demand (COD), and the total contents of phenolic and aromatic compounds. Reductions in COD were an average 6% and 20% in wastewaters diluted to 50% and 10% respectively. Average removal of aromatic compounds were 40% and 70% for both dilutions, while total phenolic content degradations was around 90% in all cases. An approximate kinetic study for design purposes was developed: the apparent kinetic constants for phenolic compounds are evaluated and correlated as a function of temperature and pH.

UV photodegradation of phenolic aldehydes present in industrial wastewaters

Abstract: The photodegradation of aqueous solutions of Vanillin aldehyde (4‐hydroxy‐3‐methoxy benzaldehyde), an important pollutant present in wastewaters generated in different agro‐industrial plants, has been carried out by direct polychromatic UV radiation. The oxidation experiments were performed at different temperatures and pH. In order to evaluate the radiation flow rate absorbed by the solutions, the line source spherical emission model is used. The application of this model provides the determination of the reaction quantum yields which are well correlated by an expression which takes into account the influence of the temperature on them.