The limited efficiency of nitrogen removal has traditionally hindered wide application of simultaneous nitrification and denitrification (SND) technology. Here, the nitrogen removal characteristics of a sequencing batch reactor were studied by adopting a strategy of a step-feeding mode, synergistic regional oxygen limitation, and a mixed carbon source. The changes of the microbial population succession and nitrogen metabolism functional genes were analyzed. This strategy provided a favorable level of dissolved oxygen and continuous carbon sources for driving the denitrification process. The total nitrogen removal efficiency and SND rate reached 92.60% and 96.49%, respectively, by regulating the ratio of sodium acetate to starch in the step feed to 5:1. This procedure increased the relative abundance of denitrifying functional genes and induced the growth of a variety of traditional denitrifying bacteria and aerobic denitrifying bacteria participating in the process of nitrogen removal. Overall, this work offers a new strategy for achieving efficient SND.
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http://dx.doi.org/10.1016/j.biortech.2022.127440 | DOI Listing |
Front Chem
January 2025
Department of Energy Chemistry and Materials Engineering, Shanxi Institute of Energy, Jinzhong, China.
A highly efficient and widely applicable adsorbent for the removal of methylene blue (MB) was created using nitrogen-doped and reduced graphene oxide (NRGO). The effects of NRGO mass, pH, contact time, and the initial MB concentration on the adsorption properties of MB onto NRGO were investigated. The results showed that the adsorption behavior remained stable within the pH range of 2.
View Article and Find Full Text PDFEnviron Res
January 2025
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Siping Road, Shanghai 200092, P. R. China. Electronic address:
The anammox dynamic membrane bioreactor (DMBR) exhibits potential for efficient nitrogen removal via anammox processes. The functional membrane biofilm in the anammox DMBR significantly enhances nitrogen removal, ensuring robust operation. Nevertheless, ecological mechanisms underpinning the nitrogen removal function of the membrane biofilm remain unclear.
View Article and Find Full Text PDFEnviron Res
January 2025
Department of Environmental Engineering, Chungbuk National University, Cheongju, Chungbuk 28644, Republic of Korea. Electronic address:
Volatile organic compounds (VOCs), such as toluene, are hazardous air pollutants that pose significant health and environmental risks. This study addresses remediation of toluene by developing a bifunctional nitrogen-doped biochar (NDB) activated with sodium hydroxide (NaOH), aimed at reducing toluene emissions through both adsorption and catalytic oxidation. A series of NDB samples were prepared via NaOH activation and pyrolysis at varying temperatures to optimize their adsorption capacity and catalytic performance.
View Article and Find Full Text PDFPNAS Nexus
January 2025
Thrust of Earth, Ocean and Atmospheric Sciences Function Hub, The Hong Kong University of Science and Technology (Guangzhou), Guangzhou 511453, China.
Modulating the electronic structure of noble metals via electronic metal-support interaction (EMSI) has been proven effectively for facilitating molecular oxygen activation and catalytic oxidation reactions. Nevertheless, the investigation of the fundamental mechanisms underlying activity enhancement has primarily focused on metal oxides as supports, especially in the catalytic degradation of volatile organic compounds. In this study, a novel Pt catalyst supported on nitrogen-doped carbon encapsulating FeNi alloy, featuring ultrafine Pt nanoparticles, was synthesized.
View Article and Find Full Text PDFPeerJ
January 2025
Further Tide Eco-Construction (Hubei) Co., Ltd, Wuhan, China.
Constructed wetland (CW) technology has attracted much attention due to its economical and environmentally friendly features. The low dissolved oxygen (DO) and low carbon/nitrogen (C/N) ratio in the wetland influent water affect the treatment performance of CW, resulting in a decrease in the removal efficiency of ammonia nitrogen (NH -N) and nitrate nitrogen (NO -N). In order to address this problem, this study optimized the pollutants removal performance of unsaturated vertical flow constructed wetland (UVFCW) by adding sustained-release carbon sources (corn cobs + polybutylene adipate terephthalate (PBAT)).
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