The Pearl River Estuary (PRE) has long received tremendous amounts of anthropogenic nitrogen, and is facing severe environmental problems. Denitrification and anaerobic ammonium oxidation (anammox) are known to be two major nitrogen removal pathways in estuarine sediments. Through the use of slurry and intact sediment core incubations, we examined the nitrogen removal pathways and quantified the in situ denitrification and anammox with associated gaseous nitrogen production rates. Sedimentary nitrogen removal was predominated by denitrification (93-100%) relative to a minimal contribution (<7%) from anammox. Among the detected environmental factors, salinity, bottom water NO (nitrate and nitrite) concentration, sedimentary organic matter and dissolved oxygen consumption rates showed good correlations with denitrification and anammox rates. Sedimentary nitrogen loss was mainly supported by endogenic coupled nitrification-denitrification (6.0 ± 1.5 × 10 mol N d), with water-column-delivered NO (2.1 ± 0.6 × 10 mol N d) as the secondary source. Such results suggested that sedimentary nitrogen removal involved mainly particulate organic form (allochthonous or autochthonous) deposited onto sediments, rather than inorganic forms in overlying water. Meanwhile, total NO production from sediments was estimated to be 7.3 ± 2.1 × 10 mol N d, equivalent to ~35% of the daily NO emissions in the PRE.
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http://dx.doi.org/10.1016/j.scitotenv.2018.08.109 | DOI Listing |
Environ Sci Pollut Res Int
January 2025
Department of Environmental Management, College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda.
Aquaculture generates substantial amount of residual feeds and faecal matter that accumulate in the culture environment and pollute effluent-receiving water, diminishing its ecological functioning. To devise means of treating nutrient-rich aquaculture wastewater, the efficiency of integrated papyrus-bivalve mesocosms in removing nutrients was evaluated. The mesocosms were fed on water (6600 L) from one brood-stock pond and allowed to settle for 2 weeks.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Physical Chemistry, Gdańsk University of Technology, Narutowicza 11/12, Gdańsk, 80-233, Poland.
The study investigated the degradation of 3-methoxy-1-propanol (3M1P) by OH using the M06-2X/6-311++G(d, p) level, with CCSD(T) single-point corrections. We focused on hydrogen atom abstraction from various alkyl groups within the molecule. The rate coefficient for 3M1P degradation was calculated from the sum of the rate coefficients corresponding to the removal of H-atoms from primary (-CH), secondary (-CH-), tertiary (-CH< ), and alcohol (-ΟH) groups.
View Article and Find Full Text PDFEnviron Res
January 2025
Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210095, China. Electronic address:
Understanding the performance and microbial succession in nitrogen removal using fermentation liquid as carbon source can provide a practical basis for treating low C/N ratio wastewater. In this study, three typical fermentation liquids of food waste (FW) enriched with lactic acid (LA), propionic acid (PA), and butyric acid (BA) were added to high ammonia and high salt (HAHS) wastewater treatment process. Results showed that effluent TN decreased from 50 mg/L to around 15 mg/L with the influent concentration around 1000 mg/L after adding fermentation liquid enriched with LA and PA.
View Article and Find Full Text PDFJ Environ Manage
January 2025
College of Eco-environmental Technology, Guangdong Industry Polytechnic University, Guangzhou, 510300, China.
Nitrogen-removal promotion is a significant problem when biological nitrogen removal is used to treat ammonium nitrogen (NH-N) wastewater with a low chemical oxygen demand (COD)/NH-N (C/N) ratio. In this work, the biological nitrogen removal capacity of the biological contact oxidation reactor (BCOR) system was enhanced through the enrichment of Acidobacteria. The system was successfully started from Day 1 to Day 50 and stably operated through temperature, pH, and dissolved oxygen (DO) regulation from Day 51 to Day 254.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Research Center for Carbon-Neutral Environmental & Energy Technology, Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu 611731, China.
As primary air pollutants from fossil fuel combustion, the excess emission of nitric oxides (NO) results in a series of atmospheric environmental issues. Although the selective catalytic reduction technology has been confirmed to be effective for NO removal, green purification and value-added conversion of NO under ambient conditions are still facing great challenges, especially for nitrogen resource recovery. To address that, photo-/electrocatalysis technology offers sustainable routes for efficient NO purification and upcycling under ambient temperature and pressure, which has received considerable attention from scientific communities.
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