Bioelectrochemically-assisted nitrogen removal in osmotic membrane bioreactor

2020 ◽  
Author(s):  
You Wu ◽  
Yun Cai ◽  
Yu-Xiang Lu ◽  
Li-Min Zhang ◽  
Xiao-Li Yang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Operation Mode ◽  
Oxygen Demand ◽  
Denitrifying Bacteria ◽  
Future Research ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrite Oxidizing Bacteria

Abstract Nitrogen removal in osmosis membrane bioreactor (OMBR) is important to its applications but remains a challenge. In this study, a bioelectrochemically-assisted (BEA) operation was integrated into the feed side of OMBRs to enhance nitrogen removal, and sodium acetate was served as a draw solute and supplementary carbon source for the growth of denitrifying bacteria due to reversed-solute. The effects of operation mode and influent ammonium (NH4+) concentration were systematically examined. Compared to a conventional OMBR, the integrated BEA-OMBR achieved higher total nitrogen removal efficiency of 98.13%, and chemical oxygen demand removal efficiency of 95.83% with the influent NH4+-N concentration of 39 mg L−1. The sequencing analyses revealed that ammonia-oxidizing bacteria (0–0.04%), nitrite-oxidizing bacteria (0–0.16%), and denitrifying bacteria (1.98–8.65%) were in abundance of the microbial community in the feed/anode side of integrated BEA-OMBR, and thus BEA operation increased the diversity of the microbial community in OMBR. Future research will focus on improving nitrogen removal from a high ammonium strength wastewater by looping anolyte effluent to the cathode. These findings have demonstrated that BEA operation can be an effective approach to improve nitrogen removal in OMBRs toward sustainable wastewater treatment.

scholarly journals Performance and microbial community of the CANON process in a sequencing batch membrane bioreactor with elevated COD/N ratios

2020 ◽  
Vol 81 (1) ◽  
pp. 138-147
Author(s):  
Xiaoling Zhang ◽  
Xincong Liu ◽  
Meng Zhang
Keyword(s):  
Organic Matter ◽  
Microbial Community ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Ammonia Oxidation ◽  
Heterotrophic Bacteria ◽  
Removal Rate ◽  
Ammonia Oxidizing Bacteria ◽  
Anaerobic Ammonia Oxidation ◽  
Canon Process

Abstract In this study, the effects of elevated chemical oxygen demand/nitrogen (COD/N) ratios on nitrogen removal, production and composition of the extracellular polymer substances (EPS) and microbial community of a completely autotrophic nitrogen removal via nitrite (CANON) process were studied in a sequencing batch membrane bioreactor (SBMBR). The whole experiment was divided into two stages: the CANON stage (without organic matter in influent) and the simultaneous partial nitrification, anaerobic ammonia oxidation and denitrification (SNAD) stage (with organic matter in influent). When the inflow ammonia nitrogen was 420 mg/L and the COD/N ratio was no higher than 0.8, the addition of COD was helpful to the CANON process; the total nitrogen removal efficiency (TNE) was improved from approximately 65% to more than 75%, and the nitrogen removal rate (NRR) was improved from approximately 0.255 kgN/(m3·d) to approximately 0.278 kgN/(m3•d), while the TNE decreased to 60%, and the NRR decreased to 0.236 kgN/(m3•d) when the COD/N ratio was elevated to 1.0. For the EPS, the amounts of soluble EPS (SEPS) and loosely bound EPS (LB-EPS) were both higher in the CANON stage than in the SNAD stage, while the amount of tightly bound EPS (TB-EPS) in the SNAD stage was significantly higher due to the proliferation of heterotrophic bacteria. The metagenome sequencing technique was used to analyse the microbial community in the SBMBR. The results showed that the addition of COD altered the structure of the bacterial community in the SBMBR. The amounts of Candidatus ‘Anammoxoglobus’ of anaerobic ammonia oxidation bacteria (AAOB) and Nitrosomonas of ammonia oxidizing bacteria (AOB) both decreased significantly, and Nitrospira of nitrite oxidizing bacteria (NOB) was always in the reactor, although the amount changed slightly. A proliferation of denitrifiers related to the genera of Thauera, Dokdonella and Azospira was found in the SBMBR.

scholarly journals Effects of Temperature on the Characteristics of Nitrogen Removal and Microbial Community in Post Solid-Phase Denitrification Biofilter Process

2019 ◽  
Vol 16 (22) ◽  
pp. 4466 ◽  
Author(s):  
Zhang ◽  
Chen ◽  
Luo ◽  
Wu ◽  
Liu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Nitrogen Removal ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Solid Phase ◽  
High Energy ◽  
Denitrifying Bacteria ◽  
Effect Of Temperature ◽  
Carbon Substrate ◽  
Ammonia Oxidizing Bacteria ◽  
Low Carbon

In order to solve the problems of high energy consumption, complex process and low nitrogen removal efficiency in the currently available low carbon source wastewater treatment processes, a novel coagulation sedimentation/post-solid-phase denitrification biofilter process (CS-BAF-SPDB) was proposed. The effect of temperature on the nitrogen removal performance of BAF-SPDB was intensively studied, and the mechanism of the effect of temperature on nitrogen removal performance was analyzed from the perspective of microbial community structure by using the polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that, to realize favorable nitrifying and denitrifying performance simultaneously in the BAF-SPDB unit, the operation temperature should be set above 18 °C. In addition, the influence of the macro operation parameters on the performance of the BAF and SPDB has a direct relationship with the dynamic changes of the micro microbial community. The influence of temperature on nitrification performance in BAF was mainly embodied in the change of composition, amount and activity of ammonia oxidizing bacteria Candidatus Nitrospira defluvii and nitrite oxidizing bacteria Nitrosomonas sp. Nm47, while that on denitrification performance in SPDB is mainly embodied in the change of composition and amount of solid carbon substrate degrading denitrifying bacteria Pseudomonas sp., Myxobacterium AT3-03 and heterotrophic denitrifying bacteria Dechloromonas agitate, Thauera aminoaromatica, Comamonas granuli and Rubrivivax gelatinosus.

scholarly journals Nitrogen Removal by Sulfur-Based Carriers in a Membrane Bioreactor (MBR)

Membranes ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 115 ◽  
Author(s):  
Thi-Kim-Quyen Vo ◽  
Jeong-Jun Lee ◽  
Joon-Seok Kang ◽  
Seogyeong Park ◽  
Han-Seung Kim
Keyword(s):  
Removal Efficiency ◽  
Total Phosphorus ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Oxygen Demand ◽  
Autotrophic Denitrification ◽  
Nitrogen Gas ◽  
Sulfate Ions ◽  
Major Disadvantage ◽  
Bioreactor System

Sulfur-based carriers were examined to enhance the nitrogen removal efficiency in a mixed anoxic–anaerobic-membrane bioreactor system, in which sulfur from the carrier acts as an electron donor for the conversion of nitrate to nitrogen gas through the autotrophic denitrification process. A total nitrogen removal efficiency of 63% was observed in the system with carriers, which showed an increase in the removal efficiency of around 20%, compared to the system without carriers. The results also indicated that the carriers had no adverse effect on biological treatment for the organic matter and total phosphorus. The removal efficiencies for chemical oxygen demand (COD) and total phosphorus (TP) were 98% and 37% in both systems, respectively. The generation of sulfate ions was a major disadvantage of using sulfur-based carriers, and resulted in pH drop. The ratio of sulfate in the effluent to nitrate removed in the system ranged from 0.86 to 1.97 mgSO42−/mgNO3−-N, which was lower than the theoretical value and could be regarded as due to the occurrence of simultaneous heterotrophic and autotrophic denitrification.

Effects of recirculation and separation times on nitrogen removal in baffled membrane bioreactor (B-MBR)

2018 ◽  
Vol 77 (12) ◽  
pp. 2803-2811 ◽  
Author(s):  
T. Miyoshi ◽  
T. Tsumuraya ◽  
T. P. Nguyen ◽  
K. Kimura ◽  
Y. Watanabe
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Membrane Bioreactor ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Nitrogen And Phosphorus ◽  
Experimental Apparatus ◽  
Do Concentration

Abstract In this study, we investigated the effects of recirculation and separation times on removals of organic matter, nitrogen, and phosphorus in a baffled membrane bioreactor (B-MBR) treating real municipal wastewater. A pilot-scale B-MBR experimental apparatus was operated under two different sets of recirculation and separation times. The results revealed that, irrespective of operating conditions, the biochemical oxygen demand (BOD) and concentration of total nitrogen (T-N) in the treated water can be lowered to less than 3 and 5 mg/L, respectively. Although T-N was effectively removed in the two different operating conditions, increase in the fraction of recirculation time results in tiny deterioration of nitrogen removal efficiency in the B-MBR. Phosphorus removal efficiency was also slightly decreased as the fraction of recirculation time (ratio between recirculation and separation times) was increased. The results of the measurement of dissolved oxygen (DO) profiles at different points of the B-MBR apparatus indicate that the increase in DO concentration in the anoxic zone of the B-MBR becomes much more pronounced by increasing recirculation intensity. On the basis of the results obtained in this study, it can be concluded that efficient removal of BOD, T-N, and total phosphorus can be achieved by the B-MBR as long as appropriate recirculation intensity is selected.

scholarly journals Light as a Novel Inhibitor of Nitrite-Oxidizing Bacteria (NOB) for the Mainstream Partial Nitrification of Wastewater Treatment

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 346
Author(s):  
Keugtae Kim ◽  
Yong-Gyun Park
Keyword(s):  
Wastewater Treatment ◽  
Blue Light ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Partial Nitrification ◽  
Biological Nutrient Removal ◽  
Nitrite Accumulation ◽  
Light Illumination ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrite Oxidizing Bacteria

Conventional biological nutrient removal processes in municipal wastewater treatment plants are energy-consuming, with oxygen supply accounting for 45–75% of the energy expenditure. Many recent studies examined the implications of the anammox process in sidestream wastewater treatment to reduce energy consumption, however, the process did not successfully remove nitrogen in mainstream wastewater treatment with relatively low ammonia concentrations. In this study, blue light was applied as an inhibitor of nitrite-oxidizing bacteria (NOB) in a photo sequencing batch reactor (PSBR) containing raw wastewater. This simulated a biological nitrogen removal system for the investigation of its application potential in nitrite accumulation and nitrogen removal. It was found that blue light illumination effectively inhibited NOB rather than ammonia-oxidizing bacteria due to their different sensitivity to light, resulting in partial nitrification. It was also observed that the NOB inhibition rates were affected by other operational parameters like mixed liquor suspended solids (MLSS) concentration and sludge retention time (SRT). According to the obtained results, it was concluded that the process efficiency of partial nitrification and anammox (PN/A) could be significantly enhanced by blue light illumination with appropriate MLSS concentration and SRT conditions.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

scholarly journals Operational modifications for the development of nitrifying bacteria in a large-scale biological aerated filter and its impact on wastewater treatment

2018 ◽  
Vol 78 (8) ◽  
pp. 1704-1714 ◽  
Author(s):  
François-René Bourgeois ◽  
Frédéric Monette ◽  
Daniel G. Cyr
Keyword(s):  
Large Scale ◽  
Oxygen Demand ◽  
Bacterial Biofilm ◽  
Nitrifying Bacteria ◽  
Nitrification Rate ◽  
Total Biomass ◽  
Ammonia Oxidizing Bacteria ◽  
Operational Conditions ◽  
Nitrite Oxidizing Bacteria ◽  
Aerated Filter

Abstract To develop a better understanding for fixed biomass processes, the development of a nitrifying bacterial biofilm, as well as the performance of treatment during modifications to operational conditions of a full-scale submerged biological filter were examined. The development of the nitrifying biofilm was investigated at four depth levels (1, 2, 4 and 5 feet). The result of bacterial subpopulations analyzed by qPCR relative to the physico-chemical parameters of the wastewater during the various tests (sustained aeration, modified backwash parameters and inflow restriction) revealed an increase of the relative presence of nitrifying microorganisms throughout the biofilm (especially for nitrite oxidizing bacteria (NOB)), but this was not necessarily accompanied by a better nitrification rate. The highest observed nitrification rate was 49% of removal in the test cell during backwashing conditions, whereas the relative ammonia oxidizing bacteria (AOB) population was 0.032% and NOB was 0.008% of the total biomass collected. The highest percentage of nitrifying bacteria observed (0.034% AOB and 0.18% NOB) resulted in a nitrification rate of 21%. The treatment of organic matter determined by measuring the chemical and biochemical oxygen demand (COD, CBOD5) was improved.

scholarly journals Micro-pressure swirl reactor (MPSR) for efficient COD and nitrogen removal of high-concentration wastewater

2020 ◽  
Vol 82 (9) ◽  
pp. 1795-1807 ◽  
Author(s):  
Dejun Bian ◽  
Zebing Nie ◽  
Fan Wang ◽  
Shengshu Ai ◽  
Suiyi Zhu ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Lower Cost ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Swirl Flow ◽  
High Concentration ◽  
Internal Circulation ◽  
Carbon And Nitrogen ◽  
Pressure Swirl

Abstract A micro-pressure swirl reactor (MPSR) was developed for carbon and nitrogen removal of wastewater, in which dissolved oxygen (DO) gradient and internal circulation could be created by setting the aerators along one side of the reactor, and micro-pressure could be realized by sealing most of the top cap and increasing the outlet water level. In this study, velocity and DO distribution in the reactor was measured, removal performance treating high-concentration wastewater was investigated, and the main functional microorganisms were analyzed. The experiment results indicated that there was stable swirl flow and spatial DO gradient in MPSR. Operated in sequencing batch reactor mode, distinct biological environments spatially and temporally were created. Under the average influent condition of chemical oxygen demand (COD) concentration of 2,884 mg/L and total nitrogen (TN) of 184 mg/L, COD removal efficiency and removal loading was 98% and 1.8 kgCOD/(m3·d) respectively, and TN removal efficiency and removal loading reached up to 90% and 0.11 kgTN/(m3·d) respectively. With efficient utilization of DO and simpler configuration for simultaneous nitrification and denitrification, the MPSR has the potential of treating high-concentration wastewater at lower cost.

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