Mature aerobic granular sludge (AGS) was inoculated in a continuous-flow reactor to treat low ammonia sewage, and the feasibility of achieving partial nitritation in a continuous-flow aerobic sludge system and the demand for value (the ratio of dissolved oxygen and ammonia nitrogen) when partial nitritation is achieved at different temperatures (30, 20, and 10℃) were investigated. The control strategy was designed to maintain a constant ratio between dissolved oxygen (DO) and ammonia nitrogen (NH-N). The results revealed that stable nitritation in a continuous-flow aerobic sludge reactor could be achieved via ratio control, and the value of were 0.50 (±0.05), 0.35 (±0.03), and 0.20 (±0.02) at the temperatures 30, 20, and 10℃, respectively, from which it can be concluded that stronger oxygen-limiting conditions were required when the temperature was lower. The experiment of fluorescence hybridization (FISH) revealed that ammonia oxidizing bacteria (AOB) have a certain concentration, and the relative number of nitrite oxidizing bacteria (NOB) gradually reduced through the ratio control strategy. Based on the ratio control strategy and the characteristics of wastewater quality, full nitritation of high ammonia wastewater may be allowed; however, for low ammonia wastewater, only partial nitritation is recommended.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.13227/j.hjkx.201708067 | DOI Listing |
J Environ Manage
January 2025
School of Artificial Intelligence, Xidian University, No. 2 South Taibai Road, Xi'an, Shaanxi, 710071, China.
In the process of partial nitrification and anaerobic ammonia oxidation (anammox) for nitrogen removal, the process offers simple metabolic pathways, low operating costs, and high nitrogenous loading rates. However, since the partial nitrification-anammox (PN-anammox) process combines partial nitrification and anammox reactions within the same reactor, strict control of dissolved oxygen (DO) is essential. Additionally, assessing treatment performance through chemical measurement involves time lag, making it challenging to recover the biological process when issue arise, especially in the PN-anammox process, where strict DO control and the sensitivity of anammox bacteria to conditions and substrates demand timely intervention.
View Article and Find Full Text PDFWater Res
January 2025
National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China. Electronic address:
Hydroxylamine (HA) dosing is an effective strategy for promoting partial nitrification (PN); however, its impact on endogenous denitrification remains underexplored. In this study, long-term continuous HA dosing (1.4 mg/L) was introduced for over 110 days in a pilot-scale anaerobic/aerobic/anoxic (AOA) system treating municipal wastewater (66.
View Article and Find Full Text PDFEnviron Res
January 2025
Key Laboratory of Water Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing, 100123, China; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China.
Stable inhibition of nitrite-oxidizing bacteria (NOB) is a significant challenge in achieving partial nitrification (PN) and partial nitrification-anaerobic ammonia oxidation (PNA). Growing evidence suggested that NOB can develop resistance to suppression over time, leading to the re-enrichment of NOB within reactors. To address these issues, this study aimed to achieve stable PN by regulating SRT to selectively washout NOB during the lag phase of activity recovery following FA/FNA exposure.
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 Hazard Mater
December 2024
College of Environmental Science and Engineering, Institute of Carbon Neutrality, State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China.
Anaerobic digestion (AD) reject water serves as a significant reservoir for antibiotic resistance genes (ARGs), underscoring the importance of understanding ARGs dynamics during treatment processes. Partial nitritation /anammox (PN/A) has become an increasingly adopted process, while comprehensive investigation on ARG behavior within this system, especially in full-scale, remains limited. This study explores the distribution of ARGs in a full-scale two-stage PN/A system, with an anaerobic/anoxic/oxic (AAO) system for comparison.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!