The aim of this study was to improve the nutrient removal efficiency by optimizing aeration time, hydraulic loading rate (HLR) and combination type in hybrid constructed wetlands (HCWs) with anoxic/oxic (A/O) reactor. The results showed that, the highest removal percentages of TN, NH-N, TP, PO-P and COD were 87.9%, 98.1%, 86.1%, 85.3% and 95.2%, respectively, in horizontal subsurface flow (HF) - surface flow - vertical subsurface flow CW with A/O reactor at 0.1 m/d HLR and 2 h aeration. HLR, aeration time and combination type had a significant impact on the removal of nutrients, though plant diversity did not have any significant influence. Presence of the A/O reactor improved the removal of TN in the HCWs by reducing influent loading and changing influent characteristics, thereby affecting the role of nitrification, anammox, and denitrification processes. The anammox process was the dominant pathway in the 1 HF CWs during the aeration period, where the highest removal of phosphorus was observed.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jenvman.2019.110026 | DOI Listing |
Environ Technol
November 2024
College of Civil Engineering, Zhejiang University of Technology, Hangzhou, People's Republic of China.
The effectiveness of three different treatment units (anaerobic, anoxic, and aerobic) in A/A/O reactors when treating landfill leachate that contained varying concentrations of tetracycline (TC) was evaluated. The effluent quality, sludge performance, and removal rates of COD, TN, TP, and NH-N of the reactors were investigated. The results showed that in the three treatment units (anaerobic, anoxic, and aerobic), when the TC dosage was 10 mg/L, the removal rates of NH-N continued to decrease to 6.
View Article and Find Full Text PDFEnviron Technol
November 2024
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, People's Republic of China.
Nitrogen removal from the combined anaerobic digestion dehydration liquor (CADDL) of municipal sludge and urban organic wastes is challenging due to high ammonium concentrations, low C/N ratio, and poor biodegradability. This study proposes a multi-stage anoxic/oxic (A/O) sequencing batch reactor with step feeding to realize partial nitrification and denitrification for shortcut nitrogen removal from the CADDL. We investigated the effects of external carbon source (acetate), dissolved oxygen (DO), A/O duration ratio, and A/O stage number on biological nitrogen removal.
View Article and Find Full Text PDFSci Total Environ
December 2024
Key Laboratory of Biotechnology and Bioresources Utilization, Ministry of Education, Dalian Minzu University, 18 Liaohe Road West, Dalian Economic and Technological Development Reactor, Dalian 116600, China; College of Environment and Resources, Dalian Minzu University, 18 Liaohe West Road, Dalian 116600, China.
J Environ Manage
November 2024
School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao, 266525, China. Electronic address:
As industrial and agricultural production depends on water supply, it is crucial for economic development. The available freshwater reserves on Earth are insufficient to meet humanity's growing demands. This study establishes a three-stage anoxic/oxic (A/O)-moving bed biofilm reactor (MBBR) system.
View Article and Find Full Text PDFWater Res
November 2024
Nanyang Environment and Water Research Institute, Nanyang Technological University, 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 639798, Singapore. Electronic address:
The iron redox cycle can enhance anammox in treating low-strength ammonia wastewater. However, maintaining an effective iron redox cycle and suppressing nitrite-oxidizing bacteria in a one-stage partial nitritation and anammox (PN/A) process poses challenges during long-term aeration. We proposed a novel and simple strategy to achieve an efficient iron redox cycle in an iron-mediated anoxic-microaerobic (A/O) process by controlling organic matter (OM) at medium-strength levels (30-110 mg COD/L) in microaerobic granular sludge (MGS)-dominated reactor.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!