A Fenton-like oxidation process using corrosion of iron metal sheet surfaces in the presence of hydrogen peroxide: a batch process study using model pollutants.

This study evaluates a new method for chemically destroying organic pollutants in wastewater using spontaneous corrosion of iron metal sheet surfaces in the presence of hydrogen peroxide. Model pollutants (phenol and benzoic acid) were degraded in batch experiments to investigate which parameters affected the process performance. Iron metal sheet surfaces spontaneously corrode under acidic conditions producing iron species (mainly ferrous ions) dissolved in aqueous solution, which react with hydrogen peroxide via the Fenton reaction. In order to optimise the oxidation system, several factors (pH, H2O2 dosage, initial concentration of organic substances) affecting corrosion of the iron metal sheet surface were investigated. Total iron concentration in solution was investigated with different dosages of H2O2 (100 mg l(-1), 1000 mg l(-1) and 1900 mg l(-1)) at different pH values (1.5, 2.5 and 3.0). Iron corrosion increased with the decrease of pH. The addition of H2O2 resulted in a significant increase of iron corrosion. Organic substances also had a marked effect with, for instance, the presence of phenol or benzoic acid resulting in a considerable increase of iron corrosion. In contrast, the absence of either hydrogen peroxide or iron metal brought no change in total organic carbon (TOC). In order to obtain the most effective combination of parameters for TOC removal of phenol solution, experiments were conducted under varied conditions. The experimental results showed that there is an optimum pH requirement (in this work, 2.5). The factors affecting the TOC removal are discussed and the oxidation mechanisms leading to mineralization of organic substances are proposed.