Does intermittent aeration and/or an influent distributary affect nitrogen removal and nitrous oxide emission of an ecological soil wastewater infiltration system?

2019 ◽  
Vol 79 (7) ◽  
pp. 1417-1425 ◽  
Author(s):  
Yue Zhao ◽  
Zhiyu Zhang ◽  
Ziqi Li ◽  
Shiyao Wang ◽  
Chaoquan Tan ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Emission Rate ◽  
N2o Emission ◽  
Functional Genes ◽  
Intermittent Aeration ◽  
Anaerobic Conditions ◽  
N Removal ◽  
The Matrix ◽  
Removal Efficiencies

Abstract The effect of intermittent aeration and an influent distributary on NH4+-N removal, total nitrogen (TN) removal, nitrous oxide (N2O) emission and the abundances of nitrogen removal and N2O emission functional genes in four types of ecological soil wastewater infiltration systems (ESWISs) (which were conventional ESWIS 1 (operated without aeration and influent distributary), ESWIS 2 (operated with intermittent aeration), ESWIS 3 (operated with influent distributary) and ESWIS 4 (operated with intermittent aeration and influent distributary)) were studied. Intermittent aeration in ESWIS 2 and 4 created aerobic conditions above 50 cm depth of the matrix and anoxic or anaerobic conditions in the lower matrix (below 80 cm depth). ESWIS 4 improved NH4+-N (to 90.1%) and TN (to 87.8%) removal efficiencies and increased the abundances of eight nitrogen removal and N2O emission functional genes (amoA, nxrA, narG, napA, nirS, nirK, qnorB and nosZ) in contrast with other ESWISs. The combination of intermittent aeration and influent distributary achieved the lowest N2O emission rate of 34.7 mg/(m2 d) in ESWIS 4. Intermittent aeration combined with influent distributary was recommended for ESWISs to enhance nitrogen removal and reduce N2O emission.

Does influent COD/N ratio affect nitrogen removal and N2O emission in a novel biochar-sludge amended soil wastewater infiltration system (SWIS)?

2018 ◽  
Vol 78 (2) ◽  
pp. 347-357 ◽  
Author(s):  
Fanping Zheng ◽  
Chaoquan Tan ◽  
Wanyuan Hou ◽  
Linli Huang ◽  
Jing Pan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Emission Rate ◽  
N2o Emission ◽  
Nitrifying Bacteria ◽  
N2o Emissions ◽  
Intermittent Aeration ◽  
Ratio Increase ◽  
Removal Rates ◽  
N Removal ◽  
Amended Soil

Abstract Nitrogen removal and N2O emission of a biochar-sludge amended soil wastewater infiltration system (SWIS) with/without intermittent aeration under different influent COD/N ratios was investigated. Nitrogen removal and N2O emission were affected by influent COD/N ratio. Under a COD/N ratio between 1:1 and 15:1, average chemical oxygen demand (COD), NH4+-N and total nitrogen (TN) removal rates decreased with COD/N ratio increase in non-aerated SWISs amended with/without biochar-sludge; an increasing COD/N ratio hardly affected COD and NH4+-N removal in a biochar-sludge amended SWIS with intermittent aeration; the N2O emission rate decreased with COD/N ratio increase in the studied SWISs. The biochar-sludge amended SWIS with intermittent aeration achieved high COD (92.2%), NH4+-N (96.8%), and TN (92.7%) removal rates and a low N2O emission rate (10.6 mg/(m2 d)) under a COD/N ratio of 15:1, which was higher than those in non-aerated SWISs amended with/without biochar-sludge. Combining the biochar-sludge amended SWIS with intermittent aeration enhanced the number of nitrifying bacteria, denitrifying bacteria, nitrate reductase activities, nitrite reductase activities, and improved the abundance of nitrogen removal functional genes under a high influent COD/N ratio. The results suggested that the joint use of intermittent aeration and biochar-sludge in a SWIS could be an effective and appropriate strategy for improving nitrogen removal and reducing N2O emissions in treating high COD/N ratio wastewater.

Nitrogen removal and N2O emission by shunt distributing wastewater in aerated or non-aerated subsurface wastewater infiltration systems under different shunt ratios

2018 ◽  
Vol 78 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Fanping Zheng ◽  
Yue Zhao ◽  
Zhiqi Li ◽  
Chaoquan Tan ◽  
Jing Pan ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Emission Rate ◽  
Oxygen Demand ◽  
N2o Emission ◽  
Functional Gene ◽  
Intermittent Aeration ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Functional Gene Abundance ◽  
Combined Strategy

Abstract This study investigated matrix oxidation–reduction potential (ORP), nitrogen removal, N2O emission and nitrogen removal functional gene abundance in three subsurface wastewater infiltration systems (SWISs), named SWIS A (without aeration or shunt distributing wastewater), SWIS B (with shunt distributing wastewater) and SWIS C (with intermittent aeration and shunt distributing wastewater) under different shunt ratios. Aerobic conditions were produced at a depth of 50 cm and anoxic or anaerobic conditions were not changed at depths of 80 and 110 cm by aeration in SWIS C. High average removal rates of chemical oxygen demand (COD) (83.1% for SWIS B, 90.9% for SWIS C), NH3-N (74.3% for SWIS B, 90.8% for SWIS C) and total nitrogen (TN) (61.1% for SWIS B, 87.9% for SWIS C) were obtained under shunt ratios of 1:3 and 1:2 for SWIS B and C, respectively. The lowest N2O emission rate (28.4 mg/(m2 d)) and highest nitrogen removal functional gene abundances were achieved in SWIS C under a 1:2 shunt ratio. The results suggested intermittent aeration and shunt distributing wastewater combined strategy would enhance nitrogen removal and reduce N2O emission for SWISs.

scholarly journals Confirmation the optimal aeration parameters for nitrogen removal and nitrous oxide emission in wastewater ecological soil infiltration systems with brown earth

2019 ◽  
Vol 80 (1) ◽  
pp. 144-152 ◽  
Author(s):  
Yafei Sun ◽  
Junling Pang ◽  
Shiyao Wang ◽  
Tingting Tao ◽  
Xun Fu ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Removal ◽  
Emission Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
N2o Emission ◽  
Aeration Rate ◽  
Soil Infiltration ◽  
Aeration Time ◽  
Domestic Wastewater Treatment

Abstract Nitrogen removal is an obstacle for the wide application of wastewater ecological soil infiltration (WESI) system in domestic wastewater treatment. In this study, matrix dissolved oxygen (DO), nitrogen removal and nitrous oxide (N2O) emission in aerated pilot WESI systems were investigated under different aeration times (1, 2, 3, 4 and 6 h/d) and aeration rates (1, 2, 3 and 4 L/min). The results showed that aerobic conditions in upper matrix and anoxic or anaerobic conditions in the subsequent matrix were developed in an aerated/non-aerated cycle at the optimal aeration condition of aeration time of 4 h/d and aeration rate of 3 L/min. Simultaneously, high removal efficiency of chemical oxygen demand (COD) (97.9%), NH4+-N (98.2%), total nitrogen (TN) (90.7%) and low N2O emission rate (13.2 mg/(m2 d)) were obtained. The results would provide optimal aeration parameters for application of intermittent aerated WESI systems.

scholarly journals Characteristics of N2O Emission and Nitrogen Removal at A DO Controlled Intermittent Aeration Activated Sludge Process.

1998 ◽  
Vol 34 (2) ◽  
pp. 1-14 ◽  
Author(s):  
YUZURU KIMOCHI ◽  
YUHEI INAMORI ◽  
NOBORU FURUYA ◽  
TOICHI EBISUNO ◽  
MASATOSHI MATSUMURA
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
N2o Emission ◽  
Activated Sludge Process ◽  
Intermittent Aeration

Effects of chemical oxygen demand (COD)/N ratios on pollutants removal in the subsurface wastewater infiltration systems with/without intermittent aeration

2016 ◽  
Vol 73 (11) ◽  
pp. 2662-2669 ◽  
Author(s):  
Siyu Song ◽  
Jing Pan ◽  
Shiwei Wu ◽  
Yijing Guo ◽  
Jingxiao Yu ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Oxygen Deficiency ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Intermittent Aeration ◽  
Oxidation Reduction ◽  
The Matrix ◽  
Pollutants Removal

The matrix oxidation reduction potential level, organic pollutants and nitrogen removal performances of eight subsurface wastewater infiltration systems (SWISs) (four with intermittent aeration, four without intermittent aeration) fed with influent chemical oxygen demand (COD)/N ratio of 3, 6, 12 and 18 were investigated. Nitrification of non-aerated SWISs was poor due to oxygen deficiency while higher COD/N ratios further led to lower COD and nitrogen removal rate. Intermittent aeration achieved almost complete nitrification, which successfully created aerobic conditions in the depth of 50 cm and did not change anoxic or anaerobic conditions in the depth of 80 and 110 cm. The sufficient carbon source in high COD/N ratio influent greatly promoted denitrification in SWISs with intermittent aeration. High average removal rates of COD (95.68%), ammonia nitrogen (NH4+-N) (99.32%) and total nitrogen (TN) (89.65%) were obtained with influent COD/N ratio of 12 in aerated SWISs. The results suggest that intermittent aeration was a reliable option to achieve high nitrogen removal in SWISs, especially with high COD/N ratio wastewater.

scholarly journals Pollutants removal, greenhouse gases emission and functional genes in wastewater ecological soil infiltration systems: influences of influent surface organic loading and aeration mode

2021 ◽  
Vol 83 (7) ◽  
pp. 1619-1632
Author(s):  
Jingna Chen ◽  
Zefang Jiang ◽  
Yue Chen ◽  
Yu Qiu ◽  
Tingting Tao ◽  
...  
Keyword(s):  
Greenhouse Gases ◽  
Removal Efficiency ◽  
Emission Rate ◽  
Oxygen Demand ◽  
N2o Emission ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Soil Infiltration ◽  
N Removal ◽  
Pollutants Removal

Abstract The influences of influent surface organic loading rate (SOLR) and aeration mode on matrix oxygen, organic matter, nitrogen, phosphorus removal, greenhouse gases emission and functional gene abundances in lab-scale wastewater ecological soil infiltration systems (WESISs) were investigated. In WESISs, intermittent or continuous aeration improved oxygen supply at 50 cm depth and hardly changed anaerobic condition below 80 cm depth, which enhanced chemical oxygen demand (COD), NH4+-N, total nitrogen (TN) removal, the abundances of bacterial 16S rRNA, amoA, nxrA, narG, napA, nirK, nirS, qnorB, nosZ genes and reduced CH4, N2O conversion efficiencies with SOLR of 16.9 and 27.6 g BOD/(m2 d) compared with non-aeration. Increased SOLR resulted in high TN removal, low N2O emission in aeration WESIS, which was different from non-aeration WESIS. High average COD removal efficiency of 90.7%, NH4+-N removal efficiency of 87.0%, TN removal efficiency of 84.6%, total phosphorus (TP) removal efficiency of 93.1% and low average N2O emission rate of 12.8 mg/(m2 d) were achieved with SOLR of 16.9 g BOD/(m2 d) in intermittent aeration WESIS. However, continuous aeration WESIS obtained high average removal efficiencies of 90.1% for COD, 87.5% for NH4+-N, 84.1% for TN, 92.9% for TP and low average emission rate of 13.1 mg/(m2 d) for N2O with SOLR of 27.6 g BOD/(m2 d). Aeration could be an optional strategy for WESISs to achieve high pollutants removal and low CH4, N2O emission when treating wastewater with high SOLR.

scholarly journals Pathways of N removal and N2O emission from a one-stage autotrophic N removal process under anaerobic conditions

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kai Li ◽  
Fang Fang ◽  
Han Wang ◽  
Chao Wang ◽  
Youpeng Chen ◽  
...  
Keyword(s):  
N2o Emission ◽  
Anaerobic Conditions ◽  
Removal Process ◽  
One Stage ◽  
N Removal
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