Catalytic fixation of hydrogen sulfide over CuO-CaCO3 co-impregnated tea stalk-derived biochar

• Published in: Journal of environmental chemical engineering Vol. 12; no. 5; p. 113320
• Main Authors: Lin, Fangcong, Wang, Leiping, Dai, Xiaorong, Man, Zun, Meng, Yang, Chu, Dongtao, Yang, Yuting, Wang, Wei, Xiao, Hang, Wang, Kaiying
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2024
• Subjects: Adsorption; Biochar; Catalytic oxidation; CuO-CaCO3 co-impregnated; H2S; H2S; CuO-CaCO3 co-impregnated; Catalytic oxidation; Adsorption; Biochar
• ISSN: 2213-3437
• DOI: 10.1016/j.jece.2024.113320

Effective treatment of hydrogen sulfide (H2S) is crucial for minimizing nuisance odors from intensive livestock and poultry operations. The development of high-performance desulfurizers holds practical significance in this context. Herein, a novel CuO-CaCO3 co-impregnated biochar desulfurizer (CuxCay/BCT) was synthesized by impregnation-pyrolysis method, using waste tea stalks and metal salts as raw materials, and it is intended for the treatment of H2S at room temperature. The optimized Cu0.75Ca0.25/BC800 shows an excellent H2S removal capacity of 182.67 mg/g, which is 31 times and 5.6 times that of inactivated biochar (BC800) and copper-oxide-impregnated biochar (Cu0.75/BC800). The desulfurization mechanism of Cu0.75Ca0.25/BC800 involves synergistic effect of reactive adsorption and catalytic oxidation. CaCO3’s alkaline adsorption sites and copper-mediated activation of superoxide radicals (∙O2-) were critical in this reaction. Besides, Cu0.75Ca0.25/BC800 demonstrated excellent reusability, retaining approximately 85 % of its initial H2S removal capacity after seven cycles of desulfurization and regeneration. This study aims to develop a metal oxide- and carbonate-impregnated biochar-based desulfurizer, with the goal of advancing the technology for catalytic removal of H2S in a more environmentally friendly and effective manner. [Display omitted] •Desulfurizer (CuxCay/BCT) was prepared successfully from waste tea stalks and metal salts.•Cu0.75Ca0.25/BC800 exhibits good desulfurization and reusability properties.•Co-impregnation with CaCO3 increased the alkaline sites on the surface of the desulfurizer.•The co-impregnating of CuO activates the superoxide ion (∙O2-), which promotes the oxidation of H2S.•The desulphurization process includes reactive adsorption and catalytic oxidation.