The removal of nitrogen from coal tar pitch (CTP) through the hydrodenitrogenation (HDN) of CTP and its molecular behavior were evaluated in the presence of NiMo/γ-alumina and CoMo/γ-alumina catalysts. Fourier transform ion cyclotron resonance mass spectrometry with atmospheric pressure photoionization was used to analyze the complicated chemical classes and species of CTP and the treated products at the molecular level. Nitrogen species were qualitatively analyzed before and after hydrotreatment. A single-stage hydrotreatment with an HDN catalyst resulted in a high sulfur removal performance (85.6-94.7%) but a low nitrogen removal performance (26.8-29.2%). Based on relative abundance analyses of nitrogen and binary nitrogen species, CH-NS was the most challenging species to remove during HDN treatment. Furthermore, prior hydrodesulfurization was combined with HDN treatment, and the dual hydrotreatments yielded a significantly improved nitrogen removal performance (46.4-48.7%).
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http://dx.doi.org/10.3390/ijms241411793 | DOI Listing |
Environ Res
December 2024
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, No. 73 Huanghe Road, Nangang District, Harbin 150090, China. Electronic address:
Iron-dependent denitrification has been substantially investigated worldwide due to the advantages of low cost, high efficiency, and synchronized phosphorous removal. However, differences in nitrogen metabolism processes with different iron-based materials as electron donors have not been systematically studied. This study investigated the efficacy of nitrogen and phosphate removal using various iron-based materials as electron donors.
View Article and Find Full Text PDFBioresour Technol
December 2024
Shanghai Municipal Engineering Design Institute (Group) Co., Ltd., Shanghai 200092, China.
Mainstream anammox faces challenges in adapting to non-optimal temperatures and managing greenhouse gas emissions. This study investigates nitrogen removal and NO emissions in attached-growth anammox reactors subjected to rapid temperature shifts (15 - 55 °C). Temperature reductions to 15 - 25 °C had minimal impact on the anammox bacterial populations, with nitrogen removal rates of 0.
View Article and Find Full Text PDFBioresour Technol
December 2024
Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China; Engineering Research Centre of Chemical Pollution Control, Ministry of Education, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu, 210094, China. Electronic address:
Anammox coupled partial S-driven autotrophic denitrification (PSAD) technology represents an innovative approach for removing nitrogen from wastewater. The research highlighted the crucial role of biofilm on sulfur particles in the nitrogen removal process. Further analysis revealed that sulfur-oxidizing bacteria (SOB) are primarily distributed in the inner layer of the biofilm, while anammox bacteria (AnAOB) are relatively evenly distributed in inner and outer layers, with Thiobacillus and Candidatus Brocadia being the dominant species, respectively.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Department of Water and Wastewater Engineering, School of Urban Construction, Wuhan University of Science and Technology, Wuhan, 430065, China. Electronic address:
The microalgal-bacterial granular sludge (MBGS) process shows potential for carbon-neutral wastewater treatment, yet its application in wastewater treatment plants remains underexplored. This study attempted to use a continuous-flow raceway reactor to treat real municipal wastewater using the MBGS process. The results showed that the removal efficiencies of organics peaked on the fifth day, while declining trends were observed for nitrogen and phosphorus removal.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
School of Environment and Ecology, Jiangnan University, Wuxi, 214122, China.
Invasive alien plants pose a great threat to local plants and ecosystems. How to effectively alleviate this hazard is an unresolved issue. This study explored the carbon release characteristics of an invasive plant Spartina alterniflora and evaluated the ability of nitrogen removal from shrimp culture wastewater through constructing seawater wetland.
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