scholarly journals Effect of Electrostatic Field Strength on Bioelectrochemical Nitrogen Removal from Nitrogen-Rich Wastewater

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3218
Author(s):  
Anna Joicy ◽  
Young-Chae Song ◽  
Jun Li ◽  
Sang-Eun Oh ◽  
Seong-Ho Jang ◽  
...  
Keyword(s):  
Field Strength ◽  
Nitrogen Removal ◽  
Electrostatic Field ◽  
Removal Rate ◽  
Bulk Solution ◽  
Cyclic Voltammogram ◽  
Batch Reactors ◽  
Taxonomic Profiling ◽  
Interspecies Electron Transfer ◽  
Nitrite Removal

The effect of electrostatic fields on the bioelectrochemical removal of ammonium and nitrite from nitrogen-rich wastewater was investigated at strengths ranging from 0.2 to 0.67 V/cm in bioelectrochemical anaerobic batch reactors. The electrostatic field enriched the bulk solution with electroactive bacteria, including ammonium oxidizing exoelectrogens (AOE) and denitritating electrotrophs (DNE). The electroactive bacteria removed ammonium and nitrite simultaneously with alkalinity consumption through biological direct interspecies electron transfer (DIET) in the bulk solution. However, the total nitrogen (ammonium and nitrite) removal rate increased from 106.1 to 166.3 mg N/g volatile suspended solids (VSS).d as the electrostatic field strength increased from 0.2 to 0.67 V/cm. In the cyclic voltammogram, the redox peaks corresponding to the activities of AOE and DNE increased as the strength of the electrostatic field increased. Based on the microbial taxonomic profiling, the dominant genera involved in the bioelectrochemical nitrogen removal were identified as Pseudomonas, Petrimonas, DQ677001_g, Thiopseudomonas, Lentimicrobium, and Porphyromonadaceae_uc. This suggests that the electrostatic field of 0.67 V/cm significantly improves the bioelectrochemical nitrogen removal by enriching the bulk solution with AOE and DNE and promoting the biological DIET between them.

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.

The characteristics of nitrogen removal by the biofilter system

2000 ◽  
Vol 42 (12) ◽  
pp. 137-147 ◽  
Author(s):  
C.F. Ouyang ◽  
R.J. Chiou ◽  
C.T. Lin
Keyword(s):  
Biological Activity ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Bulk Solution ◽  
Hydraulic Loading ◽  
Recycle Ratio ◽  
Total Nitrogen Removal ◽  
Set Up

Previous research has shown that nitrogen from municipal wastewater could be eliminated by a biofilter system. In this study a system of combined pre-denitrification/nitrification biofilters was set up. It is to investigate the effect of the hydraulic loading and recycled ratio on nitrogen removal. The characteristics of bacterial activity at different heights is discussed. The experiment shows that longer hydraulic loading would result in better total nitrogen removal. Total nitrogen removal might be not dependent on denitrification but nitrification. Hydraulic loading that affects nitrification might be due to the diffusion of NH3–N from the bulk solution to the inner biofilm. The recycling NO3–N could be completely eliminated in the anoxic biofilter. The operation with longer retention time (HRT of 12 hours) would result in inner denitrification in the aerobic biofilter. Biological activity could be determined by the distribution of bacteria. The specific rates of pollutant decomposition depend on biological activity and effective biological VSS. The effect of the recycled ratio on the nitrogen removal is significant. Total nitrogen removal rate and nitrogen type of effluent would be determined by recycle ratio. The operation at low recycled ratio would result in worse total nitrogen removal, but the NH3–N of effluent would be lower. The operation in higher recycle ratio would be opposite to low recycle ratio.

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 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.

The comparison of trichloroethylene removal rates by methane- and aromatic-utilizing microorganisms

1998 ◽  
Vol 38 (7) ◽  
pp. 19-24 ◽  
Author(s):  
C.-J. Lu ◽  
C. M. Lee ◽  
M.-S. Chung
Keyword(s):  
Cell Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
Batch Reactors ◽  
Initial Cell Concentration ◽  
Removal Rates ◽  
Initial Cell ◽  
Toluene Concentration ◽  
Cell Source ◽  
Removal Efficiencies

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.

Study on De-Nitrification of Improved Step-Feed Progress

2014 ◽  
Vol 703 ◽  
pp. 171-174
Author(s):  
Bing Wang ◽  
Yi Xiao ◽  
Shou Hui Tong ◽  
Lan Fang ◽  
Da Hai You ◽  
...  
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Fluidized Bed ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
Operating Conditions ◽  
Removal Mechanism ◽  
Aerobic Zone

Improved step-feed de-nitrification progress combined with biological fluidized bed was introduced in this study. The progress had good performance and capacity of de-nitrification and organic matter. The experiment result showed that the de-nitrification efficiency of the improved biological fluidized bed with step-feed process was higher than the fluidized bed A/O process under the same water quality and the operating conditions. When the influent proportion of each segment was equal, the system showed good nitrogen removal efficiency with the change of influent C/N ratio, HRT and sludge return ratio. The removal rate of TN reached up to 88.2%. It showed that the simultaneous nitrification and de-nitrification phenomenon happened in the aerobic zone. The nitrogen removal mechanism was also studied.

Effects of the combination of aeration and biofilm technology on transformation of nitrogen in black-odor river

2016 ◽  
Vol 74 (3) ◽  
pp. 655-662 ◽  
Author(s):  
Mei Pan ◽  
Jun Zhao ◽  
Shucong Zhen ◽  
Sheng Heng ◽  
Jie Wu
Keyword(s):  
Enzyme Activity ◽  
Nitrogen Removal ◽  
Removal Rate ◽  
River Networks ◽  
Water Tank ◽  
Simulation Experiments ◽  
Overlying Water ◽  
Combined Process ◽  
Polluted Rivers ◽  
Laboratory Water

Excess nitrogen in urban river networks leading to eutrophication has become one of the most urgent environmental problems. Combinations of different aeration and biofilm techniques was designed to remove nitrogen from rivers. In laboratory water tank simulation experiments, we assessed the removal efficiency of nitrogen in both the overlying water and sediments by using the combination of the aeration and biofilm techniques, and then analyzed the transformation of nitrogen during the experiments. Aeration (especially sediment aeration) combined with the biofilms techniques was proved efficient in removing nitrogen from polluted rivers. Results indicated that the combination of sediment aeration and biofilms, with the highest nitrogen removal rate from the overlying water and sediments, was the most effective combined process, which especially inhibited the potential release of nitrogen from sediments by reducing the enzyme activity. It was found that the content of dissolved oxygen in water could be restored on the basis of the application of aeration techniques ahead, and the biofilm technique would be effective in purifying water in black-odor rivers.

scholarly journals In Situ Water Quality Improvement Mechanism (Nitrogen Removal) by Water-Lifting Aerators in a Drinking Water Reservoir

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 1051 ◽  
Author(s):  
Zizhen Zhou ◽  
Tinglin Huang ◽  
Weijin Gong ◽  
Yang Li ◽  
Yue Liu ◽  
...  
Keyword(s):  
Drinking Water ◽  
Nitrogen Removal ◽  
High Throughput Sequencing ◽  
Removal Rate ◽  
Water Reservoir ◽  
Control Area ◽  
Nitrite Accumulation ◽  
Field Scale ◽  
Drinking Water Reservoir ◽  
N Removal

A field scale experiment was performed to explore the nitrogen removal performance of the water and surface sediment in a deep canyon-shaped drinking water reservoir by operating WLAs (water-lifting aerators). Nitrogen removal performance was achieved by increasing the densities and N-removal genes (nirK and nirS) of indigenous aerobic denitrifiers. After the operation of WLAs, the total nitrogen removal rate reached 29.1 ± 0.8% in the enhanced area. Ammonia and nitrate concentrations were reduced by 72.5 ± 2.5% and 40.5 ± 2.1%, respectively. No nitrite accumulation was observed. Biolog results showed improvement of carbon metabolism and carbon source utilization of microbes in the enhanced area. Miseq high-throughput sequencing indicated that the denitrifying bacteria percentage was also higher in the enhanced area than that in the control area. Microbial communities had changed between the enhanced and control areas. Thus, nitrogen removal through enhanced indigenous aerobic denitrifiers by the operation of WLAs was feasible and successful at the field scale.

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.

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