scholarly journals Construction of autotrophic nitrogen removal system based on zero-valent iron (ZVI): performance and mechanism

2020 ◽  
Vol 82 (12) ◽  
pp. 2990-3002
Author(s):  
Han Yang ◽  
Liangwei Deng ◽  
Youqian Xiao ◽  
Hongnan Yang ◽  
Hong Wang ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Inorganic Nitrogen ◽  
Zero Valent Iron ◽  
Batch Reactors ◽  
Ammonium Oxidation ◽  
N Accumulation ◽  
Ferric Ammonium ◽  
Tin Removal ◽  
Performance And Mechanism

Abstract In this study, the performance and mechanism of nitrogen removal in sequencing batch reactors (SBRs) with and without zero-valent iron (ZVI) was investigated. The results showed that ZVI had a capacity to promote -N conversion, -N accumulation and total inorganic nitrogen (TIN) removal, with the TIN removal rate being increased by 29.45%. The ZVI also had a significant impact on microbial community structure by means of high-throughput pyrosequencing, increasing the enrichment of Anammox (anaerobic ammonium oxidation) bacteria Candidatus Brocadia and Feammox (anaerobic ferric ammonium oxidation) bacteria Ignavibacterium. With ZVI addition, the main pathway of nitrogen removal was changed from nitrification-heterotrophic denitrification to Anammox and Feammox.

scholarly journals Promotion of partial nitritation-anammox process by improving granule proportion

2017 ◽  
Vol 75 (11) ◽  
pp. 2580-2585 ◽  
Author(s):  
Jun Cheng ◽  
Liang Zhang ◽  
Yandong Yang ◽  
Shujun Zhang ◽  
Xiaoyu Han ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
System Performance ◽  
Mass Fraction ◽  
Removal Rate ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Ammonium Oxidation ◽  
Partial Nitritation ◽  
Granule Fraction ◽  
Anammox Process

For enhancing the partial nitritation-anammox (PN/A) process, the effects of granule fraction on system performance were investigated in this study. Two sequencing batch reactors (SBRs) were inoculated with PN/A biomass with a floc mass fraction of 53%. In SBR1, when the nitrogen removal rate (NRR) was stable, flocculent sludge was gradually discharged from the reactor using a screen, and the granule fraction was therefore increased. However, nitrogen removal was not improved and finally deteriorated due to the loss of nitritation activity. In SBR2, most flocculent sludge was eliminated and granular proportion was maintained at over 90% by controlling a short settling and decanting time. NRR was low initially but gradually improved to 1.23 kg N/(m3·d), which was 54% higher than SBR1. Ammonium oxidation activities of flocs and granules were respectively measured. Results suggested that the increase of nitritation activity in the granules was the main reason for the improvement of nitrogen removal in SBR2.

scholarly journals Anammox biofilm process using sugarcane bagasse as an organic carrier

2021 ◽  
Vol 26 (1) ◽  
pp. 25
Author(s):  
Zulkarnaini Zulkarnaini ◽  
Puti Sri Komala ◽  
Arief Almi
Keyword(s):  
Sugarcane Bagasse ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Nitrogen Loading ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Ammonium Oxidation ◽  
Biofilm Process ◽  
Anaerobic Sludge Blanket ◽  
Anammox Process

The anaerobic ammonium oxidation (anammox) biofilm process commonly uses various inorganic carriers to enhance nitrogen removal under anaerobic conditions. This study aims to analyze the performance of nitrogen removal in anammox process using sugarcane bagasse as an organic carrier. The experiment was carried out by using an up‐flow anaerobic sludge blanket (UASB) reactor for treating artificial wastewater at room temperature. The reactor was fed with ammonium and nitrite with the concentrations of 70‐150 mg–N/L and variations in the hydraulic retention time of 24 and 12 h. The granular anammox belongs to the genus Candidatus Brocadia sinica that was added as an inoculum of the reactor operation. The experimental stoichiometric of anammox for ΔNO2‐–N: ΔNH4+–N and ΔNO3‐: ΔNH4+ were 1.24 and 0.18, respectively, which is similar to anammox stoichiometry. The maximum Nitrogen Removal Rate (NRR) has achieved 0.29 kg–N/m3.d at Nitrogen Loading Rate (NLR) 0.6 kg–N/m3.d. The highest ammonium conversion efficiency (ACE) and nitrogen removal efficiency (NRE) were 88% and 85%, respectively. Based on this results, it indicated that sugarcane bagasse as organic carriers could increase the amount of total nitrogen removal by provided of denitrification process but inhibited the anammox process at a certain COD concentration.

scholarly journals Enhanced Nitrogen Removal from Domestic Wastewater by Partial-Denitrification/Anammox in an Anoxic/Oxic Biofilm Reactor

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 109
Author(s):  
Yu Huang ◽  
Yongzhen Peng ◽  
Donghui Huang ◽  
Jiarui Fan ◽  
Rui Du
Keyword(s):  
Nitrogen Removal ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Biofilm Reactor ◽  
Anammox Bacteria ◽  
Stable Operation ◽  
Ammonium Oxidation ◽  
N Accumulation ◽  
Carbon Demand ◽  
Oxidation Efficiency

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.

scholarly journals Impact of mixing intensity on dissolved oxygen half-velocity constants in a sidestream deammonification environment

2019 ◽  
Vol 55 (2) ◽  
pp. 145-154
Author(s):  
Biao Xie ◽  
Chao Jin ◽  
Wayne J. Parker
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Bulk Phase ◽  
Batch Reactors ◽  
Ammonia Oxidizing Bacteria ◽  
Mixing Conditions ◽  
Steady State Operation ◽  
Mixing Intensity ◽  
Best Fit

Abstract A partial nitritation/anammox (PN/A) process was operated at two different mixing intensities to quantify the extent to which diffusional limitations impact process rates. At a steady-state operation, the total inorganic nitrogen removal efficiency in the bench-scale sequencing batch reactors was found to increase as mixing intensity decreased (62 and 84% for average velocity gradient (G) values of 15 and 5.3 s−1, respectively). The half-velocity constants with respect to bulk-phase dissolved oxygen (DO) concentration for ammonia-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing (anammox) organisms were estimated on the basis of nitrogen removal rates that were observed in activity tests. The activity tests were conducted over a range of bulk-phase DO concentrations. The best-fit values were estimated to be 0.68 ± 0.34 and 0.54 ± 0.56 mg O2/L for G values of 15 and 5.3 s−1, respectively. The AOB values were not statistically different (p = 0.19) between mixing conditions which were consistent with AOB dominating the surface of granules. The best-fit values were estimated to be 0.13 ± 0.09 and 0.55 ± 0.40 mg O2/L for G values of 15 and 5.3 s−1, respectively, and were statistically different . The results demonstrated that mixing conditions should be considered when designing PN/A processes and provide quantitative results that can be employed to improve models of these processes. This article has been made Open Access thanks to the kind support of CAWQ/ACQE (https://www.cawq.ca).

High nitrogen removal rate using ANAMMOX process at short hydraulic retention time

2013 ◽  
Vol 67 (5) ◽  
pp. 968-975 ◽  
Author(s):  
C. G. Casagrande ◽  
A. Kunz ◽  
M. C. De Prá ◽  
C. R. Bressan ◽  
H. M. Soares
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Ammonium Oxidation ◽  
High Nitrogen ◽  
Total N ◽  
Column Reactor ◽  
Anaerobic Sludge Blanket ◽  
Anammox Process

The anaerobic ammonium oxidation (ANAMMOX) is a chemolithoautotrophic process, which converts NH4+ to N2 using nitrite (NO2−) as the electron acceptor. This process has very high nitrogen removal rates (NRRs) and is an alternative to classical nitrification/denitrification wastewater treatment. In the present work, a strategy for nitrogen removal using ANAMMOX process was tested evaluating their performance when submitted to high loading rates and very short hydraulic retention times (HRTs). An up-flow ANAMMOX column reactor was inoculated with 30% biomass (v v−1) fed from 100 to 200 mg L−1 of total N (NO2−-N + NH4+-N) at 35 °C. After start-up and process stability the maximum NRR in the up-flow anaerobic sludge blanket (UASB) reactor was 18.3 g-N L−1 d−1 operated at 0.2 h of HRT. FISH (fluorescence in situ hybridization) analysis and process stoichiometry confirmed that ANAMMOX was the prevalent process for nitrogen removal during the experiments. The results point out that high NRRs can be obtained at very short HRTs using up-flow ANAMMOX column reactor configuration.

High-Concentration Nitrogen Removal by Anaerobic Ammonium Oxidation Process

2012 ◽  
Vol 518-523 ◽  
pp. 214-217
Author(s):  
Tao Hong Liao ◽  
Kang Huai Liu ◽  
Jia Chun Yang ◽  
Kenji Furukawa
Keyword(s):  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Ammonium Oxidation ◽  
High Concentration ◽  
Total Nitrogen Concentration ◽  
Load Rate ◽  
Nitrogen Load Rate

This experiment aimed to explore the effect of high- concentration nitrogen removal by Anaerobic ammonium oxidation process. The mixed liquor suspended solid(MLSS)was 510 mg/L. In the beginning of the experiment, the inflow concentration rate of ammonia nitrogen and nitrite nitrogen was about 1:1.3 and the total nitrogen concentration was low. When the reactor reached the ideal treatment effect then gradually increased the total nitrogen concentration, until reaching the maximum nitrogen load rate(NLR) of the reactor. In the temperature of 34.4 °C, PH was 7.23, the inflow concentration of ammonia nitrogen was 223.3 mg. N/L, the inflow concentration nitrite nitrogen was 289.7 mg. N/L, the dissolved oxygen (DO) was 2.3 mg. N/L, the nitrogen load rate (NLR) was 6.08 kg. N / (m3. d), the nitrogen removal rate (NRR) was 5.60 kg. N / (m3. d), the total nitrogen (TN) removal rate was 92.2%, under this conditions, the reactor achieved the best effect.

Treatment of septage using single and two stage activated sludge batch reactors systems

1995 ◽  
Vol 32 (9-10) ◽  
pp. 95-104 ◽  
Author(s):  
A. D. Andreadakis ◽  
G. Kondili ◽  
D. Mamais ◽  
A. Noussi
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Substantial Reduction ◽  
Subsequent Treatment ◽  
Batch Reactors ◽  
Two Stage ◽  
Second Stage ◽  
Nitrogen Concentrations ◽  
Stage System

The cyclic or sequencing batch activated sludge process was applied for the treatment of septage originating from cesspools serving non-sewered areas. Single and two stage systems were investigated in bench scale units. The single stage aerated system was capable in removing practically all the biodegradable COD and producing a well stabilised excess sludge with excellent settling and thickening characteristics. With respect to nitrogen the average removal rate was to the order of 70%, but the performance was unstable due to periodic strong inhibition of the nitrification process. Subsequent treatment in a second stage aerated unit improved nitrification but did not result in higher nitrogen removal rates due to the increased concentrations of oxidised nitrogen. An anoxic second stage post denitrification unit resulted in an overall nitrogen removal of 88%, through a substantial reduction of nitrates. Further improvement of the system, with nitrogen removal of about 95% and average effluent nitrogen concentrations lower than 10 mg.1−1, can be achieved by adoption of a two stage system consisting of a first aerated stage unit, followed by a second stage unit with alternating aerated and anoxic cycles and addition of external carbon during the anoxic cycle.

scholarly journals Newly established process combining partial hydrogenotrophic denitrification and anammox for nitrogen removal

2020 ◽  
Vol 82 (7) ◽  
pp. 1272-1284
Author(s):  
Kenta Shinoda ◽  
Rawintra Eamrat ◽  
Yuya Tsutsumi ◽  
Suphatchai Rujakom ◽  
Tippawan Singhopon ◽  
...  
Keyword(s):  
Nitrogen Removal ◽  
Production Efficiency ◽  
Inorganic Nitrogen ◽  
Amplicon Sequencing ◽  
Ammonium Nitrogen ◽  
Great Promise ◽  
Rrna Gene ◽  
Ammonium Oxidation ◽  
Initial Ph ◽  
Anammox Process

Abstract The anaerobic ammonium oxidation (anammox) process holds great promise for treating nitrogen-contaminated water; stable nitrite-nitrogen (-N) production is significant to anammox performance. In this study, partial hydrogenotrophic denitrification (PHD) was used to stably and efficiently produce -N from nitrate-nitrogen (-N). An investigation of the effects of initial pH on the PHD process revealed that a high -N production efficiency (77.9%) could be ensured by setting an initial pH of 10.5. A combined PHD-anammox process was run for more than three months with maximal ammonium-nitrogen (-N), -N, and total dissolved inorganic nitrogen removal efficiencies of 93.4, 98.0, and 86.9%, respectively. The -N to -N and -N to -N ratios indicated that various bioprocesses were involved in nitrogen removal during the anammox stage, and a 16S rRNA gene amplicon sequencing was performed to further clarify the composition of microbial communities and mechanisms involved in the nitrogen removal process.

scholarly journals Coupled anaerobic ammonium oxidation and hydrogenotrophic denitrification for simultaneous NH4-N and NO3-N removal

2018 ◽  
Vol 79 (5) ◽  
pp. 975-984 ◽  
Author(s):  
Tatsuru Kamei ◽  
Rawintra Eamrat ◽  
Kenta Shinoda ◽  
Yasuhiro Tanaka ◽  
Futaba Kazama
Keyword(s):  
Nitrogen Removal ◽  
Inorganic Nitrogen ◽  
Nitrate Removal ◽  
Fixed Bed ◽  
Anaerobic Ammonium Oxidation ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
N Removal ◽  
Anammox Process

Abstract Nitrate removal during anaerobic ammonium oxidation (anammox) treatment is a concern for optimization of the anammox process. This study demonstrated the applicability and long-term stability of the coupled anammox and hydrogenotrophic denitrification (CAHD) process as an alternative method for nitrate removal. Laboratory-scale fixed bed anammox reactors (FBR) supplied with H2 to support denitrification were operated under two types of synthetic water. The FBRs showed simultaneous NH4-N and NO3-N removal, indicating that the CAHD process can support NO3-N removal during the anammox process. Intermittent H2 supply (e.g. 5 mL/min for a 1-L reactor, 14/6-min on/off cycle) helped maintain the CAHD process without deteriorating its performance under long-term operation and resulted in a nitrogen removal rate of 0.21 kg-N/m3/d and ammonium, nitrate, and dissolved inorganic nitrogen removal efficiencies of 73.4%, 80.4%, and 77%, respectively. The microbial community structure related to the CAHD process was not influenced by changes in influent water quality, and included the anammox bacteria ‘Candidatus Jettenia’ and a Sulfuritalea hydrogenivorans-like species as the dominant bacteria even after long-term reactor operation, suggesting that these bacteria are key to the CAHD process. These results indicate that the CAHD process is a promising method for enhancing the efficiency of anammox process.

scholarly journals Start-up of a full-scale partial nitritation-anammox MBBR without inoculum at Klagshamn WWTP

2020 ◽  
Vol 81 (9) ◽  
pp. 2033-2042 ◽  
Author(s):  
Ivelina Dimitrova ◽  
Agnieszka Dabrowska ◽  
Sara Ekström
Keyword(s):  
Nitrogen Removal ◽  
Removal Rate ◽  
Treatment Plant ◽  
Full Scale ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Ex Situ ◽  
Ammonium Oxidation ◽  
Partial Nitritation ◽  
Start Up

Abstract Partial nitritation and anaerobic ammonium oxidation (PNA) is a useful process for the treatment of nitrogen-rich centrate from the dewatering of anaerobically digested sludge. A one-stage PNA moving bed biofilm reactor (MBBR) was started up without inoculum at Klagshamn wastewater treatment plant, southern Sweden. The reactor was designed to treat up to 200 kgN d−1, and heated dilution water was used during start-up. The nitrogen removal was >80% after 111 days of operation, and the nitrogen removal rate reached 1.8 gN m−2 d1 at 35 °C. The start-up period of the reactor was comparable to that of inoculated full-scale systems. The operating conditions of the system were found to be important, and online control of the free ammonia concentration played a crucial role. Ex situ batch activity tests were performed to evaluate process performance.

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