A sequencing batch reactor (SBR) with aerobic granular sludge was operated to determine the effect of different DO concentrations on biological nitrogen removal process and to investigate the spatial profiles of DO, ORP and pH as online control parameters in such systems. The results showed that DO concentration had a significant effect on nitrification efficiencies and the profiles of DO, ORP and pH. The specific nitrification rate was decreased from 0.0595 mgNH(4)(+)-N/(gMLSS min) to 0.0251 mgNH(4)(+)-N/(gMLSS min) after DO concentration was dropped off from 4.5mg/L to 1.0mg/L. High DO concentration improved the nitrification and increased the volumetric NH(4)(+)-N removal. Low DO concentration enhanced TIN removal, while prolonged the nitrification duration. Also there existed a good correlation between online control parameters (ORP, pH) and nutrient (COD, NH(4)(+)-N, NO(2)(-)-N, NO(3)(-)-N) variations in aerobic granular sludge reactor when DO was 2.5mg/L, 3.5mg/L and 4.5mg/L. However it was difficult to identify the end of nitrification and denitrification when DO was 1.0mg/L, due to no apparent bending points on ORP and pH curves. In conclusion, the optimal DO concentration was suggested at 2.5mg/L as it not only achieved high nitrogen removal efficiency and decreased the reaction duration, but also saved operation cost by aeration and mixing.
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http://dx.doi.org/10.1016/j.jhazmat.2010.02.045 | DOI Listing |
Environ Technol
February 2025
PGEAGRI/CCET - Center of Exact Sciences and Technology, State University of Western of Paraná - UNIOESTE, Cascavel, Brazil.
The deammonification process is an efficient alternative to remove nitrogen from wastewater with a low carbon/nitrogen ratio. However, the reactor configuration and operational factors pose challenges for applications in treatment systems to remove nitrogen from municipal and industrial wastewater on a large scale. To address this gap, this study evaluated a new deammonification strategy using a single-stage membrane aerated biofilm reactor (MABR), operated with continuous flow, under different hydraulic retention times (HRT) in the post-treatment of poultry slaughterhouse wastewater with a low nitrogen load, similar to domestic wastewater.
View Article and Find Full Text PDFBioprocess Biosyst Eng
January 2025
Qingdao Shunqingyuan Environment Co., Ltd., Qingdao, 266109, Shandong, China.
Membrane bioreactors (MBRs) have been widely used in the field of wastewater treatment because of their small footprint and high treatment efficiency. In this research, 10 rural wastewater treatment sites in China that employ the MBR process were systematically studied. Specifically, treatment of actual domestic wastewater using MBRs was examined by high-throughput 16S rRNA gene sequencing to explore the microbial community composition and perform function prediction.
View Article and Find Full Text PDFChem Asian J
January 2025
Fudan University, Department of Environmental Science and Engineering, Shanghai Handan Road 220, 200433, Shanghai, CHINA.
Novel Ce1-xMnxVO4 catalysts prepared via modified hydrothermal synthesis were used in selective catalytic reduction of NO using NH3 (NH3-SCR). The Ce1-xMnxVO4 catalysts displayed optimum NO removal efficiency at 250 oC. Physicochemical properties including crystal type, morphology, particle size, elemental composition, BET surface area, chemical bond, and valence state were studied by XRD, TEM, EDS, N2 adsorption-desorption, Raman spectroscopy, and XPS.
View Article and Find Full Text PDFSci Rep
January 2025
Chemistry Department, Faculty of Science, Tanta University, Tanta, 31527, Egypt.
Three composites based on Poly (meta-aminophenol) (PmAP), (3-aminopropyl) triethoxysilane (APTES) and graphene oxide (GO) were synthesized with initial GO dispersion of 3.3, 6.6, and 9.
View Article and Find Full Text PDFWater Res
January 2025
College of Environmental Science and Engineering, Yangzhou University, Yangzhou 225127, PR China; Key Laboratory of Arable Land Quality Monitoring and Evaluation, Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou 225127, PR China; Joint International Research Laboratory of Agriculture and Agri-Product Safety of Ministry of Education of China, Yangzhou University, Yangzhou 225127, Jiangsu, PR China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, PR China. Electronic address:
Endogenous nitrogen (N) release from lake sediments is one of main causes affecting water quality, which can be affected by the presence of iron (Fe) minerals and organic matter, especially low-molecular-weight organic acids (LMWOAs). Although these substances always coexist in sediments, their interaction effect on N fate is not yet clear. In this study, the role and mechanisms of the coexistence of iron mineral (ferrihydrite, Fh) and LMWOAs, i.
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