Study on the photo-Fenton degradation of polyvinyl alcohol in aqueous solution

The degradation of polyvinyl alcohol (PVA) by the photo-Fenton process was studied in laboratory scale, with aim of investigating the effect of process conditions on the polymer degradation rate. The experiments were based on a complete factorial design for the amounts of Fe(II) and H2O2 added to water solutions of PVA of different concentrations. The degradation rate of the organic compounds was monitored along the time in discontinuous experiments by analyzing the dissolved organic carbon concentration (DOC) in the solutions. Under adequate conditions more than 90% of the DOC could be degraded in the process. Depending on the initial DOC concentration and the amounts of Fe(II) and H2O2 added an insoluble phase is formed, which can be separated by mechanical methods, thus favoring the removal of organic contaminants in the treatment of industrial wastewaters containing PVA. The interpretation of the experimental results was based on the fitting of neural network models for predicting solid phase formation, and DOC concentration along the reaction time.