Modified natural zeolites and clays as support of Ni–Mn catalyst for toluene oxidation in a one-stage plasma-catalysis system

• Published in: International journal of environmental science and technology (Tehran) 2022-10, Vol.19 (10), p.10307-10316
• Main Authors: Mohammad Gholipour Aghdam, A., Rahemi, N., Allahyari, S., Hoseini, S., Yousefpour, M.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Science and Engineering; Original Paper; Soil Science & Conservation; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 1735-1472; 1735-2630
• DOI: 10.1007/s13762-022-04231-7

In this paper, the degradation of toluene as a volatile organic compound was investigated by using a one-stage plasma-catalysis system. NiO (6% wt.) and MnO 2 (12% wt.) as active phase were deposited on acid- and base-treated clinoptilolite and montmorillonite as supports to evaluate the effect of physicochemical properties of the modified supports on the performance of the catalyst in toluene oxidation. Characterizations revealed that smaller NiO and MnO 2 crystallites but lower surface area were observed on base-treated supports compared to acid-treated ones. Operational conditions in the plasma-catalysis system were evaluated to find the proper conditions for the abatement of toluene. At 11.7 kHz and 20 kV, which were chosen as optimum frequency and plasma voltage, NiO-MnO 2 deposited on base-treated montmorillonite indicated the highest toluene removal of 95.56% from the polluted air stream with 3000 ppm toluene concentration. With decreasing the toluene concentration to 1000 ppm and enhancing the residence time to 7 min, toluene conversion reached to the highest value of 98.12%. A time-on stream test showed stable toluene conversion and high CO 2 selectivity over time on NiO-MnO 2 deposited on base-treated montmorillonite as well.