Pathways regulating nitrogen removal in constructed ditch wetlands: effects of different inflow ratios and artificial aeration

2020 ◽  
Vol 27 (34) ◽  
pp. 42571-42581
Author(s):  
Yuhui Ma ◽  
Peiru Zheng ◽  
Wanqing Dai ◽  
Xiangyong Zheng ◽  
Shengbing He ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Artificial Aeration

Combining artificial aeration and biological zeolite mulch for nitrogen removal from eutrophic water bodies

2020 ◽  
Vol 15 (1) ◽  
pp. 151-159
Author(s):  
Cheng Lu ◽  
Wen Cheng ◽  
Min Wang ◽  
Zhiwei Zhou
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Combined Treatment ◽  
Ammoniacal Nitrogen ◽  
Nitrogen Species ◽  
Artificial Aeration ◽  
Total Nitrogen Concentration ◽  
Eutrophic Water

Abstract Endogenous nitrogen pollution can be a major cause of eutrophication. Nitrogen species release from sediments can be reduced by biologically-enforced zeolite mulch or water column aeration. This study was about their combined effects. Water and surface sediment samples from the Yangzhou ancient canal were aerated and biozeolite mulching was applied separately and in combination for 81 days, while the nitrogen species removal rate was recorded. The combination of aeration and biozeolite mulching removed >95% of the ammoniacal-nitrogen in 15 days. This was better than either the blank control or biozeolite mulch without aeration. The ammoniacal-nitrogen concentration was lowered faster by combined treatment than by aeration alone. Nitrate nitrogen was only detected during aeration between days 10 and18, and reached lower concentration in the presence of biozeolite. Nitrate was formed during aeration but its concentrations were higher and more variable in the absence of biozeolite; that is, mulching stabilized nitrate formation. The total nitrogen concentration reached its lowest levels after 81 days with biozeolite treatment alone, with 78% total nitrogen removal, whereas combined aeration with biozeolite achieved 41%. This shows that biozeolite mulching can remove nitrogen in eutrophic waters, even without aeration.

scholarly journals Effects of hydraulic loading rate and aeration mode on nitrogen removal and nitrogen functional gene abundances in subsurface wastewater infiltration systems

2017 ◽  
Vol 76 (1) ◽  
pp. 210-218 ◽  
Author(s):  
Yafei Sun ◽  
Jing Pan ◽  
Shiyue Qi ◽  
Hexin Fei
Keyword(s):  
Nitrogen Removal ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Functional Gene ◽  
Intermittent Aeration ◽  
Anaerobic Conditions ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Artificial Aeration ◽  
Operation Cost

Matrix dissolved oxygen, nitrogen removal and nitrogen functional gene abundances in two artificial aeration modes, continuous aeration (CA) and intermittent aeration (IA), in subsurface wastewater infiltration systems (SWISs) under different hydraulic loading rates (HLRs) were investigated. Aeration not only successfully created aerobic conditions at 50 cm depth, but also did not change anoxic or anaerobic conditions at 80 and 110 cm depths. Meanwhile, aeration significantly enhanced chemical oxygen demand, NH4+-N, and total nitrogen (TN) removal and the enrichment of nitrogen removal functional genes (amoA, nxrA, napA, narG, nirK and qnorB) compared to the non-aerated SWIS, especially for high HLRs. IA SWIS (79.7%–85.8%) had a better performance on TN removal compared with CA SWIS (73.8%–82.2%) when the HLRs ranged from 0.06 to 0.3 m3/(m2 d). Intermittent aeration is a sensible strategy to achieve high HLR, good nitrogen removal performance and comparatively low operation cost for SWISs.

Enhanced nitrogen removal by the integrated constructed wetlands with artificial aeration

2019 ◽  
Vol 14 ◽  
pp. 100362 ◽  
Author(s):  
Pan Jizheng ◽  
Zhang Houhu ◽  
Lu Xuejun ◽  
Li Yong ◽  
Zhao Min ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Artificial Aeration

scholarly journals Effect of Aeration Modes and COD/N Ratios on Organic Matter and Nitrogen Removal in Horizontal Subsurface Flow Constructed Wetland Mesocosms

Water ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1530 ◽  
Author(s):  
Xin Chen ◽  
Hui Zhu ◽  
Yingying Xu ◽  
Brian Shutes ◽  
Baixing Yan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Pollutant Removal ◽  
Artificial Aeration ◽  
Influent Water ◽  
Horizontal Subsurface Flow ◽  
Aerobic And Anaerobic ◽  
Wetland Mesocosms

A series of mesocosm-scale horizontal subsurface flow constructed wetlands (HSSF-CWs) were established. In Experiment 1, four artificial aeration (AA) modes, including pre-aeration at 24 h before the input of influent water (PA), aeration at 6 h (6AA) and 12 h (12AA) after the input of influent water and non-aeration (NA), were tested to obtain an optimal aeration mode for chemical oxygen demand (CODCr) and nitrogen removal. The results showed that aeration after the input of influent water could improve the removal efficiencies of CODCr and ammonia-nitrogen (NH4⁺-N), but lead to an accumulation of nitrate-nitrogen (NO3−-N). The above observation demonstrated that a single aeration cannot create an ideal alternation of aerobic and anaerobic conditions for simultaneous nitrification and denitrification. Therefore, HSSF-CWs with intermittent aeration (IA), after the input of influent water and NA were established to evaluate the combined effects of IA and influent COD/N ratios on pollutant removal in Experiment 2. The HSSF-CW with IA exhibited a better performance in CODCr and nitrogen removal compared to HSSF-CW with NA. The highest removal percentages of CODCr (90.1%), NH4+-N (99.8%) and total nitrogen (TN, 99.5%) were achieved at a COD/N ratio of 9.3 in HSSF-CW with IA.

Nitrogen Removal in a Real-Time Controlled Sequencing Batch Membrane Bioreactor

2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu
Keyword(s):  
Real Time ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Real Time Control ◽  
Time Control ◽  
Cake Layer ◽  
On Line ◽  
Solid Liquid ◽  
Solid Liquid Separation

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.

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