Heterogeneous Fenton reaction for the treatment of ACE in residual waters of pharmacological origin using Fe-SBA-15 nanocomposites

Abstract

SBA-15 nanocomposites were synthesized using different sources of iron by direct hydrothermal synthesis. Various characterization techniques including X Ray Diffraction (XRD) at low and high angle, UV–vis diffuse reflectance spectra (UV–vis DRs) and Temperature Programmed Reduction (TPR) were conducted. The metal speciation in the solids was different depending on the used source of iron. The synthesized materials were evaluated in a heterogeneous Fenton process applied to the degradation of aqueous solutions of a commercial drug, acetaminophen (ACE). The catalyst synthesized with ferric sulphate showed the best activity which can be attributed to the presence of more isolated Fe3+ ions stabilized and accessible to reactant molecules. Using the best catalyst, the influence of pH, catalyst initial concentration and temperature on the pollutant degradation process was studied. A maximum degradation (90.8% in a reaction time of 120 min) was achieved with an initial catalyst concentration of 1000 mg L−1 at pH = 4.5 and 30 °C. In addition, under these conditions iron species leaching from the catalyst was very low, ensuring the heterogeneity of reaction, stability and possibility of catalyst reuse. Finally, this method may be very effective for pharmaceutical effluent treatment and be used in the acetaminophen industry.