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 ◽  
...  

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.

2019 ◽  
Vol 79 (7) ◽  
pp. 1417-1425 ◽  
Author(s):  
Yue Zhao ◽  
Zhiyu Zhang ◽  
Ziqi Li ◽  
Shiyao Wang ◽  
Chaoquan Tan ◽  
...  

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.


2021 ◽  
Vol 83 (7) ◽  
pp. 1619-1632
Author(s):  
Jingna Chen ◽  
Zefang Jiang ◽  
Yue Chen ◽  
Yu Qiu ◽  
Tingting Tao ◽  
...  

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.


2018 ◽  
Vol 78 (2) ◽  
pp. 329-338 ◽  
Author(s):  
Fanping Zheng ◽  
Yue Zhao ◽  
Zhiqi Li ◽  
Chaoquan Tan ◽  
Jing Pan ◽  
...  

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.


2013 ◽  
Vol 838-841 ◽  
pp. 2739-2744
Author(s):  
Shuang Zhao ◽  
Cui Ping Wang

A novel process for improving the energy use and treatment efficiency of the biological nitrogen removal process, up-flow microaerobic-oxic (M/O) process which is composed of up-flow micro-aerobic and aeration was proposed based on a laboratory scale for domestic wastewater treatment, the dissolved oxygen (DO) in up-flow micro-aerobic was in the range of (0~0.5) mg/L. The M/O process performance under different hydraulic retention time (HRT) and Internal return ratio (r) was investigated. Under the optimal conditions, the average removal efficiencies of chemical oxygen demand (COD), total nitrogen (TN) and ammonium nitrogen (NH4+-N) were 89.1%, 64.1%, and 96.6 % with effluent concentrations of COD, TN and NH4+-N less than 50,15 and 8mg/L, respectively. The distribution of sludge particles diameter and microbial activity of activated sludge were also measured, the mean particle diameter was in the range of 180~250μm and the SOURT was 13.11 mgO2/(gMLVSSh). Up-flow micro-aerobic (M/O) reactor has the advantages of more stable performance and better resistance to the load shock than the conventional A/O process within continuous running period of 130 days.


RSC Advances ◽  
2015 ◽  
Vol 5 (75) ◽  
pp. 61345-61353 ◽  
Author(s):  
Xinwen Zhang ◽  
Jian Zhang ◽  
Zhen Hu ◽  
Huijun Xie ◽  
Dong Wei ◽  
...  

The effect of influent chemical oxygen demand/nitrogen (COD/N) ratio on nitrogen removal and nitrous oxide (N2O) emission during partial nitrification treating high-strength nitrogen wastewater was investigated.


2018 ◽  
Vol 63 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Gong Cheng ◽  
Amarendra Dhar Dwivedi ◽  
Jie Fu

A large amount of domestic wastewater is produced in our daily life. To sustainably use the urban domestic wastewater in the residential area and develop the equipment for distributed domestic wastewater treatment, the present work carried out a pilot study on the treatment of domestic wastewater by sequencing batch membrane bioreactor (SBMBR). Under the conditions of 20 L/h·m2 of average water flux, and 2 h/3 h of anaerobic/aerobic period, the SBMBR process showed a good treatment effect with a good quality of effluent (<50 mg/L of chemical oxygen demand (COD), <5 mg/L of ammonia nitrogen (NH3-N), <15 mg/L of total nitrogen (TN), <2.6 NTU of turbidity, 96.9% of color removal and 99.9% of bacteria removal). The aeration quantity had a certain degree of impact on the removal of COD and the optimum aeration rate was 13.9 m3/m3·h considering both the effectiveness and cost. When the SBMBR was continuously operated for 40 days, the transmembrane pressure reached 50 kPa and the membrane needed to clean. The hydrochloric acid (pH ≈ 2) was a suitable cleaning agent and the membrane was almost completely restored after cleaning.


2015 ◽  
Vol 72 (4) ◽  
pp. 572-578
Author(s):  
Kang Song ◽  
Shohei Riya ◽  
Masaaki Hosomi ◽  
Akihiko Terada

Effect of methanol and glycerol on nitrous oxide (N2O) emission in two laboratory-scale modified Ludzak Ettinger (MLE) processes was investigated during three distinct periods: dissolved oxygen (DO) control by intermittent aeration with a DO controller, and high and low aeration rates. N2O consumption rate in an anoxic tank and aeration mode influenced N2O emission rates from the MLE processes. In the DO control period, N2O emission rate from the glycerol-fed MLE process was higher than the methanol-fed counterpart, likely caused by a higher N2O consumption rate in an anoxic tank of the methanol-fed process. During the period of a higher aeration rate, N2O emission rates from both processes were comparable. In contrast, during the period of a lower aeration rate, N2O emission rate from the methanol-fed MLE process was higher than that from the glycerol-fed counterpart likely because of a higher degree of nitrite accumulation, corroborated by statistical analysis. N2O consumption activities of biomasses fed with the different carbon sources were distinct. However, the high activity did not necessarily result in a decrease in N2O emission rate from an aerobic tank and the effect of nitrite on the emission was stronger under the tested conditions.


2018 ◽  
Vol 13 (3) ◽  
pp. 457-464
Author(s):  
PRIYANAND AGALE ◽  
PARAG SADGIR

Rural wastewater treatment is mostly ignored in developing and undeveloped countries. The most important barrier for addressing to this problem is cost of treatment and simplified technology. Aerobic Brickbat Grit Sand (ABGS) purifier consists of four stages. Wastewater flows gravitationally through partition walls in zigzag pattern with brick bats filter; Pebble sand filter and charcoal and grit filter which facilitate removal of contaminants from domestic wastewater. In the present study, experimental model for domestic wastewater treatment was setup in the Environmental Engineering laboratory at Government College of Engineering Aurangabad, Maharashtra. Physiochemical analysis was done in August and September of 2016 the percentage removal of contaminants results shows Biological Oxygen Demand (BOD) 92% - 87%, Chemical Oxygen Demand (COD) 93 - 89%, Total Suspended Solids( TSS) 80 - 78% and Turbidity 95 - 85%. The process is considered eco-friendly and easy to install technology for domestic wastewater treatment with use of locally available material. ABGS purifier is decentralized approach of domestic wastewater treatment. Hence ABGS as an alternative solution to tackle over the problem of rural wastewater treatment.


Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Yu Huang ◽  
Yongzhen Peng ◽  
Donghui Huang ◽  
Jiarui Fan ◽  
Rui Du

A partial-denitrification coupling with anaerobic ammonium oxidation (anammox) process (PD/A) in a continuous-flow anoxic/oxic (A/O) biofilm reactor was developed to treat carbon-limited domestic wastewater (ammonia (NH4+-N) of 55 mg/L and chemical oxygen demand (COD) of 148 mg/L in average) for about 200 days operation. Satisfactory NH4+-N oxidation efficiency above 95% was achieved with rapid biofilm formation in the aerobic zone. Notably, nitrite (NO2−-N) accumulation was observed in the anoxic zone, mainly due to the insufficient electron donor for complete nitrate (NO3−-N) reduction. The nitrate-to-nitrite transformation ratio (NTR) achieved was as high as 64.4%. After the inoculation of anammox-enriched sludge to anoxic zones, total nitrogen (TN) removal was significantly improved from 37.3% to 78.0%. Anammox bacteria were effectively retained in anoxic biofilm utilizing NO2−-N produced via the PD approach and NH4+-N in domestic wastewater, with the relative abundance of 5.83% for stable operation. Anammox pathway contributed to TN removal by a high level of 38%. Overall, this study provided a promising method for mainstream nitrogen removal with low energy consumption and organic carbon demand.


Sign in / Sign up

Export Citation Format

Share Document