Nb2O5 monolith as an efficient and reusable catalyst for textile wastewater treatment

Abstract

Abstract In this work, the degradation of methylene blue (MB) in aqueous solution by a heterogeneous Fenton-like process was studied. Nb2O5 supported on an anodized aluminum monolith was used as catalyst. The Nb2O5 coating generated during the catalyst synthesis was uniform and porous, with a thickness of 7 μm. Response surface methodology was used to study the relationship between process variables and MB degradation and chemical oxygen demand (COD) reduction. The optimal operating conditions were: initial MB concentration of 45 mg L− 1, initial H2O2 concentration in the reaction medium of 40 mM, catalyst loading of 7.85 kg Nb 2 O 5 $$ {\mathrm{kg}}_{{\mathrm{Nb}}_2{\mathrm{O}}_5} $$ m− 3, and pH 4, reaching a MB degradation of 98% and a COD reduction of 79% at 150 min. The high activity of the Nb2O5 monolith catalyst remained constant after 10 catalytic tests.

Keywords

• Monolithic catalyst
• Niobia
• Anodic alumina
• Dye
• Methylene blue