Marisa Canterino

Kinetic investigation of Cu(II) ions photoreduction in presence of titanium dioxide and formic acid.

The photoreduction of Cu(II) in presence of an organic species as sacrificial agent has been investigated by many research groups but some controversial results are reported in literature. In this work, the photoreduction process of Cu(II) in presence of formic acid is investigated aiming at clarifying the reaction mechanism and assess the reaction kinetics. The effect of operating conditions such as TiO(2) load, initial concentration of sacrificial agent, pH and ionic strength was studied. The results of the work are: (1) the system reactivity does not depend neither on pH (in the range 2.0-3.5) nor on ionic strength of the solution; (2) formic acid is adsorbed on TiO(2) surface; (3) the nature of anionic species can influence the Cu(II) photoreduction (e.g. the addition of sulphate or phosphates reduces the reaction rates); and (4) FA can be completely mineralized during this photoxidation process; for example, this is observed for a TiO(2) load of 0.1g/L after a reaction time of about 240 min. A simplified kinetic model is developed to describe the behavior of the system and validated by analysing the data collected during the experimental work.

Energy recovery in wastewater decontamination: simultaneous photocatalytic oxidation of an organic substrate and electricity generation.

The contemporary removal of organic pollutants from aqueous solution and electricity generation is studied in the present work by means of an experimental device resulting from the combination of a photocatalytic reactor and an electrochemical cell. The proposed system relies on the capability of Cu2+ ions to reduce in the presence of TiO2, (solar) UV radiations and a sacrificial organic agent. In the anodic solution of the combined photoreactor-cell, Cu0 is oxidized to Cu2+ and the latter is reduced again to the lowest oxidation state. The use of different sacrificial agents ranging from formic acid (FA) to glycerol (GLY) to glucose (GLU) is investigated along with the adoption of two different cathodes for the cell, the first based again on the couple Cu2+/Cu0 and the second on the couple O2/H2O.

A Kinetic Investigation on the Ozonation of Glycerol and its Oxygenated Derivatives

The ozonation of glycerol and its main oxygenated derivatives is studied aiming at evaluating the possibility to convert them into valuable products. The direct ozonation of glycerol results into a mixture of its oxygenated derivatives. In some cases the use of ozone to convert them into valuable products proceeds with good selectivity. A kinetic study to estimate the kinetic constants of ozone attack to the main glycerol oxygenated intermediates is carried out. The data found are in keeping with the few values found in the literature for alcoholic groups by ozone.

Removal of Organic Pollutants from Soil: The Ozonation of Clofibric Acid in Aqueous Slurries

Ozonation is particularly suited for the treatment of recalcitrant soil contaminants. Clofibric acid, an active metabolite of some blood lipid regulators, was used as a model organic contaminant, and quartzite as a model soil. The measurements performed at different pHs, both in slurries of contaminated soil and in clofibric acid aqueous solutions, indicate that a markedly higher TOC removal can be obtained in the slurry mode. Ozonation kinetics in aqueous slurries was also studied in a well-mixed reactor. Suitable mathematical models were used to describe the experiments and to estimate the best values of the unknown parameters.