Fenton-Like oxidation of Orange II solution using heterogeneous catalysis with bionanocatalyst from fique fiber and iron nanoparticles

The availability of natural water resources has declined over time, becoming one of the biggest problems today. Advanced oxidation processes with iron nanoparticles applied to azo dyes in aqueous phase is one of the most... [ view full abstract ]

The availability of natural water resources has declined over time, becoming one of the biggest problems today. Advanced oxidation processes with iron nanoparticles applied to azo dyes in aqueous phase is one of the most modern innovative technologies. This work, shows how the combination of cellulosic fibers with iron oxide nanoparticles could provide exceptional biodegradable composite materials for the treatment of organic dyes in wastewater. Likewise, allows an easy separation catalyst-treated water, turning the biocatalyst in a highly recyclable and reusable material.
A catalytic wet hydrogen peroxide process was applied for the degradation of an azo dye Orange II (OII). Using as catalyst a bionanocomposite from fique fiber impregnated with iron nanoparticles; nanoparticles were prepared by borohydride reduction of an aqueous iron salt in presence of a support material. To track the impregnation process on the fiber, samples from the precursor solution were taken at different times and its iron concentration was determined by atomic absorption spectrophotometry (AAS). Complementary characterization of the catalyst was performed by SEM, XRD, FTIR, thermal analysis, XPS, XRF and BET surface area.
Tests were carried out in a slurry batch reactor, following a long time the OII degradation by UV-VIS spectroscopy. The variables studied for the catalytic activity were pH, percentage of iron, initial concentration of H2O2 and OII in the system.
Subsequent to the synthesis process, the catalyst reported 10.9 wt.%,14.9 wt.% and 13.21.5 wt.% of iron as active phase. Catalytic results under pH = 2.5, 10.9 wt. % of iron, 5.5x10-3M and 1.1x10-4M as initial concentrations of H2O2 and OII, respectively, show that this bionanocomposite presents good properties for the degradation of Orange II solutions, allowing to reach after 4h of oxidation 93.23% of dye degradation, using only 800 mg of catalyst per 250 mL of solution. Iron released into the final solution is neglectable.
These results suggest that the reduction reaction by iron nanoparticles is potentially a viable in situ treatment of wastewater contaminated with hazardous organic compounds including azo dyes.