Nitrate (NO) and sulfate (SO) often coexist in organic wastewater. The effects of different substrates on NO and SO biotransformation pathways at various C/N ratios were investigated in this study. This study used an activated sludge process for simultaneous desulfurization and denitrification in an integrated sequencing batch bioreactor. The results revealed that the most complete removals of NO and SO were achieved at a C/N ratio of 5 in integrated simultaneous desulfurization and denitrification (ISDD). Reactor Rb (sodium succinate) displayed a higher SO removal efficiency (93.79%) with lower chemical oxygen demand (COD) consumption (85.72%) than reactor Ra (sodium acetate) on account of almost 100% removal of NO in both Ra and Rb. Ra produced more S (5.96 mg L) and HS (25 mg L) than Rb, which regulated the biotransformation of NO from denitrification to dissimilatory nitrate reduction to ammonium (DNRA), whereas almost no HS accumulated in Rb which can avoid secondary pollution. Sodium acetate-supported systems were found to favor the growth of DNRA bacteria (); although denitrifying bacteria (DNB) and sulfate-reducing bacteria (SRB) were found to co-exist in both systems, Rb has a greater keystone taxa diversity. Furthermore, the potential carbon metabolic pathways of the two carbon sources have been predicted. Both succinate and acetate could be generated in reactor Rb through the citrate cycle and the acetyl-CoA pathway. The high prevalence of four-carbon metabolism in Ra suggests that the carbon metabolism of sodium acetate is significantly improved at a C/N ratio of 5. This study has clarified the biotransformation mechanisms of NO and SO in the presence of different substrates and the potential carbon metabolism pathway, which is expected to provide new ideas for the simultaneous removal of NO and SO from different media.
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http://dx.doi.org/10.1039/d3ra02749j | DOI Listing |
Environ Pollut
December 2024
State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, 100029, China; College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.
A multiple-site filter-sampling observation study was conducted in a coastal industrial city (Rizhao, 35°10'59″N, 119°23'57″E) to understand the main components, formation mechanisms, and potential sources of particulate matter. The average (±σ) mass concentration of PM across all the sites was 42 (±27) μg/m, with high variability (6∼202 μg/m). Water-soluble inorganic ions (WSIIs) were the major contributors (54%∼60%) to PM with mean values for sulfate (13 μg/m), nitrate (6 μg/m), and ammonium (7 μg/m) (SNA).
View Article and Find Full Text PDFBMC Public Health
December 2024
Department of Hospital Infection Control, Tongji Hospital, School of Medicine, Tongji University, Shanghai, 200065, China.
Nat Commun
December 2024
School of Public Health, Key Lab of Public Health Safety of the Ministry of Education, Fudan University, Shanghai, China.
Fine particulate matter has been linked with acute coronary syndrome. Nevertheless, the key constituents remain unclear. Here, we conduct a nationwide case-crossover study in China during 2015-2021 to quantify the associations between fine particulate matter constituents (organic matter, black carbon, nitrate, sulfate, and ammonium) and acute coronary syndrome, and to identify the critical contributors.
View Article and Find Full Text PDFWater Res
December 2024
Department of Sanitation and Environmental Engineering, School of Engineering, Federal University of Minas Gerais, Avenue Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG, Brazil. Electronic address:
Arsenic (As) enrichment in groundwater stems from natural and hydrogeochemical factors, leading to geological contamination. Groundwater and surface water are interconnected, allowing As migration and surface water contamination. The As contamination poses health risks through contaminated water consumption.
View Article and Find Full Text PDFACS Earth Space Chem
December 2024
University of Iowa, Iowa City, Iowa state 52242, United States.
Environmental films form when airborne particles and molecular species adsorb on solid surfaces. Recent studies have characterized these films but overlook how collection methods and host-surface character (orientation, chemical functionality, or height) change the deposition process. In this work, environmental films are collected at a rural location on gold and silicon surfaces (water contact angles of ca.
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