Chemometric Study on the TiO2-Photocatalytic Degradation of Nitrilotriacetic Acid.

C.A. EMILIO; J.F. MAGALLANES; M. I. LITTER

ANALYTICA CHIMICA ACTA

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2007 vol. 595 p. 89 - 97

0003-2670

A chemometric study on the TiO2-photocatalytic degradation of nitrilotriacetic acid (NTA) in aqueous media under UV radiation has beencarried out taking into account the multiple variables that take part in the system. To save redundant number of experiments, the system has beenmanaged under chemometric techniques for several variables as NTA and TiO2 concentrations, pH and irradiation time. Multiple-way analysisof the variance (MANOVA) has been applied to find the statistically significant variables. An artificial neural network (ANN) has been used tobuild an empirical model of the system. All measurements have been driven under experimental designs: a full-factorial design (FFD) was usedto analyze significant factors through MANOVA, and a Doehlert design, which was modified by spatial rotation, was applied in order to have asatisfactory number of levels for the factor time to be able to train the ANN. The study allows the knowledge and prediction of the behavior ofthe system as well as to work out kinetic parameters and to optimize their variables. The results of kinetic parameters obtained with the neuralnetwork agreed with independent experimental results, confirming a Langmuir–Hinshelwood kinetic regime. The difference between NTA andethylenediaminetetraacetic acid (EDTA), which has been previously studied, is also established..