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Chemical Precipitation Method for the Synthesis of Nb2O5 Modified Bulk Nickel Catalysts with High Specific Surface Area
Published on: February 19, 2018
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Cr (VI) reduction by photocatalyic process: Nb2O5 an alternative catalyst
T G Josué1, L N B Almeida2, M F Lopes1
1Federal University of Technology - Paraná - Departament of Chemical Engineering, Monteiro Lobato Avenue, Km 04, Ponta Grossa, Paraná, 84016-210, Brazil.
Journal of Environmental Management
|June 9, 2020
Summary
Niobium pentoxide (Nb2O5) effectively reduces toxic Chromium (VI) in wastewater, outperforming titanium dioxide. Optimal conditions involve non-calcined Nb2O5 under acidic pH and specific radiation intensity for efficient chromium removal.
Area of Science:
- Environmental Chemistry
- Materials Science
- Catalysis
Background:
- Hexavalent chromium (Cr(VI)) is a highly toxic pollutant prevalent in industrial tannery effluents.
- Effective and sustainable methods are needed for Cr(VI) remediation from contaminated water sources.
- Photocatalysis offers a promising avenue for pollutant degradation and removal.
Purpose of the Study:
- To investigate the efficacy of niobium pentoxide (Nb2O5) as a photocatalyst for Cr(VI) reduction.
- To compare the performance of Nb2O5 with titanium dioxide (TiO2), a common photocatalyst.
- To determine the optimal conditions for Cr(VI) reduction using Nb2O5 and assess its reusability.
Main Methods:
- Niobium pentoxide (Nb2O5) characterization using X-ray diffraction, BET surface area analysis, photo-acoustic spectroscopy, SEM, and EDS.
- Photocatalytic reduction of Cr(VI) using Nb2O5 and TiO2 under varying conditions (pH, radiation intensity, initial concentration, catalyst loading).
- Evaluation of Nb2O5 photostability and reusability over multiple reaction cycles.
Main Results:
- Nb2O5 demonstrated a 20% higher Cr(VI) reduction efficiency compared to TiO2.
- Calcination at 500°C did not enhance Nb2O5 performance; non-calcined Nb2O5 showed better results.
- Optimal conditions identified: pH 2, 250W radiation, 10 mg/L initial Cr(VI) concentration, and 1.5 g/L non-calcined Nb2O5.
- Non-calcined Nb2O5 exhibited a 21% decrease in efficiency over four reuse cycles, potentially due to higher adsorption capacity, while calcined Nb2O5 maintained ~90% photostability.
Conclusions:
- Non-calcined Nb2O5 is a highly effective and potentially more economical photocatalyst for Cr(VI) reduction compared to TiO2.
- The study identified key parameters for optimizing the photocatalytic process, offering a viable solution for industrial wastewater treatment.
- Nb2O5's performance and reusability suggest its potential for larger-scale applications in environmental remediation.
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