scholarly journals Development of anammox reactor equipped with a degassing membrane to improve biomass retention

2012 ◽  
Vol 66 (2) ◽  
pp. 451-456 ◽  
Author(s):  
Kosuke Matsunaga ◽  
Tomonori Kindaichi ◽  
Noriatsu Ozaki ◽  
Akiyoshi Ohashi ◽  
Yoshihito Nakahara ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
N2o Emission ◽  
Anammox Bacteria ◽  
Component Ratio ◽  
Reactor Performance ◽  
Contributing Factors ◽  
Nitrogen Gas ◽  
Biomass Retention ◽  
Gas Selectivity

In up-flow anammox reactors, one of the contributing factors to biomass wash-out is the adherence of nitrogen gas produced by the anammox reaction to biomass. In this study, we operated an up-flow anammox reactor equipped with a degassing membrane to minimize the biomass wash-out from the reactor by separating the produced gas from the biomass. In addition, both the effect of degassing on the anammox reactor performance and the durability of the membrane submerged in the anammox reactor were investigated. The results show that the use of the degassing membrane in the anammox reactor could (1) improve the biomass retention ability (by separating the produced gas from the biomass), and (2) increase the component ratio of anammox bacteria in the reactor. In addition, degassing could reduce the N2O emission produced in the reactor (for the gas selectivity of the degassing membrane). No membrane fouling was observed even after 2 months of operation without washing, indicating an advantage to the use of the degassing membrane.

scholarly journals Development of downflow hanging sponge (DHS) reactor as post treatment of existing combined anaerobic tank treating natural rubber processing wastewater

2016 ◽  
Vol 75 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Takahiro Watari ◽  
Trung Cuong Mai ◽  
Daisuke Tanikawa ◽  
Yuga Hirakata ◽  
Masashi Hatamoto ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Nitrogen Loading ◽  
Post Treatment ◽  
Organic Loading Rate ◽  
Anammox Bacteria ◽  
Rrna Gene ◽  
Sequencing Analysis ◽  
Reactor Performance

Conventional aerated tank technology is widely applied for post treatment of natural rubber processing wastewater in Southeast Asia; however, a long hydraulic retention time (HRT) is required and the effluent standards are exceeded. In this study, a downflow hanging sponge (DHS) reactor was installed as post treatment of anaerobic tank effluent in a natural rubber factory in South Vietnam and the process performance was evaluated. The DHS reactor demonstrated removal efficiencies of 64.2 ± 7.5% and 55.3 ± 19.2% for total chemical oxygen demand (COD) and total nitrogen, respectively, with an organic loading rate of 0.97 ± 0.03 kg-COD m−3 day−1 and a nitrogen loading rate of 0.57 ± 0.21 kg-N m−3 day−1. 16S rRNA gene sequencing analysis of the sludge retained in the DHS also corresponded to the result of reactor performance, and both nitrifying and denitrifying bacteria were detected in the sponge carrier. In addition, anammox bacteria was found in the retained sludge. The DHS reactor reduced the HRT of 30 days to 4.8 h compared with the existing algal tank. This result indicates that the DHS reactor could be an appropriate post treatment for the existing anaerobic tank for natural rubber processing wastewater treatment.

Enrichment and characterization of marine anammox bacteria associated with global nitrogen gas production

2008 ◽  
Vol 10 (11) ◽  
pp. 3120-3129 ◽  
Author(s):  
Jack van de Vossenberg ◽  
Jayne E. Rattray ◽  
Wim Geerts ◽  
Boran Kartal ◽  
Laura van Niftrik ◽  
...  
Keyword(s):  
Gas Production ◽  
Anammox Bacteria ◽  
Nitrogen Gas

Effect of heterotrophic growth on nitritation/anammox in a single sequencing batch reactor

2008 ◽  
Vol 58 (2) ◽  
pp. 277-284 ◽  
Author(s):  
Kai M. Udert ◽  
Elija Kind ◽  
Mieke Teunissen ◽  
Sarina Jenni ◽  
Tove A. Larsen
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Removal ◽  
Sequencing Batch Reactor ◽  
Heterotrophic Bacteria ◽  
Batch Reactor ◽  
Organic Substrate ◽  
Anammox Bacteria ◽  
Heterotrophic Growth ◽  
Reactor Performance ◽  
Heterotrophic Denitrification

The combination of nitritation and autotrophic denitrification (anammox) in a single sequencing batch reactor (SBR) is an energy efficient process for nitrogen removal from high-strength ammonia wastewaters. So far, the process has been successfully applied to digester supernatant. However, the process could also be suitable to treat source-separated urine, which has very high ammonium and organic substrate concentrations (up to 8,200 gN/m3 and 10,000 gCOD/m3). In this study, reactor performance was tested for digester supernatant and diluted source-separated urine. Ammonium concentrations in both solutions were similar (between 611 and 642 gN/m3), thus reactor performance could be directly compared. Differences were mainly due to higher activity of heterotrophic bacteria in urine. Nitrogen removal was slightly higher for source-separated urine, because heterotrophic bacteria denitrified the nitrate that was produced by anammox bacteria. In spite of higher heterotrophic growth with source-separated urine, calculated sludge concentrations at steady state were higher with digester supernatant due to accumulation of inert particulate organic matter from the influent. Although the sludge concentrations are less problematic for source-separated urine, process instabilities are more likely, because lower pH values are reached and heterotrophic denitrification can cause sudden increases of nitrite concentrations and/or nitric oxide. Both compounds inhibit aerobic ammonium oxidizing bacteria, heterotrophic bacteria and, most importantly, anammox bacteria. Nitrite and nitric oxide production by heterotrophic denitrification must be better understood to optimize nitritation/anammox for source-separated urine.

scholarly journals Immobilization of Anammox biomass in sodium alginate

2018 ◽  
Vol 44 ◽  
pp. 00008 ◽  
Author(s):  
Anna Banach ◽  
Aneta Pudlo ◽  
Aleksandra Ziembińska-Buczyńska
Keyword(s):  
Sodium Alginate ◽  
Wastewater Treatment Plants ◽  
Chemical Properties ◽  
Anammox Bacteria ◽  
Ammonium Oxidation ◽  
Promising Technique ◽  
Nitrogen Gas ◽  
Slow Growth Rate ◽  
Anammox Activity ◽  
And Chemical Properties

Anaerobic ammonium oxidation (anammox) is a process of ammonium and nitrite conversion into nitrogen gas. Nowadays, anammox is applied into many wastewater treatment plants worldwide. However, anammox bacteria are characterized by a slow growth rate, which may cause problems in maintaining the biomass in the system. The promising technique which can help to maintain the biomass in the reactor and effectively prevent loss of anammox bacteria from a system is immobilization. Selection and optimization of the appropriate immobilization technique for investigated biomass is crucial for conducting an effective process. One of the ways for bacteria immobilization is gel entrapment. The main goal of the study was to test sodium alginate as an immobilization medium for anammox biomass. In the present study procedure of immobilization in sodium alginate was optimised, then the mechanical and chemical properties of the obtained pellets were investigated. Series of batch experiments revealed that immobilized anammox biomass was able to remove ammonia and nitrite nitrogen effectively. The calculated specific anammox activity (SAA) for immobilized anammox biomass was 0.18 g N·gVSS-1·d-1, while for non-immobilized biomass was 0.36 g N·gVSS-1·d-1.

Fouling propensity of forward osmosis: investigation of the slower flux decline phenomenon

2010 ◽  
Vol 61 (4) ◽  
pp. 927-936 ◽  
Author(s):  
Winson C. L. Lay ◽  
Tzyy Haur Chong ◽  
Chuyang Y. Tang ◽  
Anthony G. Fane ◽  
Jinsong Zhang ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Ambient Pressure ◽  
Pure Water ◽  
Forward Osmosis ◽  
Hydraulic Pressure ◽  
Contributing Factors ◽  
Draw Solution ◽  
Flux Decline ◽  
Internal Concentration ◽  
Quality Water

Forward Osmosis (FO) is a membrane process that uses the natural osmotic pressure of a concentrated draw solution to extract pure water from a feed stream. The attraction of the FO process is that it uses dense membranes, while operating at ambient pressure. This means that the FO process could potentially produce high quality water with lower energy consumption, as compared to the other desalination or reclamation processes. As FO does not entail the use of hydraulic pressure, FO has been hypothesized to have lower fouling propensity than pressure driven membrane processes. Membrane fouling has significant impact on the operational sustainability and economics of the process. This study examines the possible contributing factors to the slower flux decline observed in FO experiments based on a combined experimental and modelling approach. It was found that these factors could include low water fluxes, use of hydrophilic and smooth membranes, and the effect of internal concentration polarisation that is inherent of FO. It was also found that the transmission of draw solutes from the draw solution into the feed can have significant effect on FO performance.

scholarly journals Assessing Enzyme Immobilization on Reverse Asymmetric Membranes and Biocatalytic Reactor Performance

2021 ◽  
Author(s):  
Amirah Syakirah Zahirulain ◽  
Fauziah Marpani ◽  
Syazana Mohamad Pauzi ◽  
'Azzah Nazihah Che Abd Rahim ◽  
Hang Thi Thuy Cao ◽  
...  
Keyword(s):  
Enzyme Immobilization ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Separation ◽  
Permeate Flux ◽  
Reactor Performance ◽  
Membrane Performance ◽  
Reverse Mode ◽  
Substrate Conversion ◽  
Product Separation

Abstract Integration of membrane filtration and biocatalysis has appealing benefits in terms of simultaneous substrate conversion and product separation in one reactor. Nevertheless, the interaction between enzymes and membrane is complex and the mechanism of enzyme docking on membrane is similar to membrane fouling. In this study, focus is given on the assessment of enzyme immobilization mechanism on reverse asymmetric polymer membrane based on the permeate flux data during the procedure. Evaluation of membrane performance in terms of its permeability, fouling mechanisms, enzyme loading, enzyme reusability and biocatalytic productivity were also conducted. Alcohol Dehydrogenase (EC 1.1.1.1), able to catalyze formaldehyde to methanol with subsequent oxidation of NADH to NAD was selected as the model enzyme. Two commercial, asymmetric, flat sheet polymer membranes (PES and PVDF) were immobilized with the enzyme in the reverse mode. Combination of concentration polarization phenomenon and pressure driven filtration successfully immobilized almost 100% of the enzymes in the feed solutions. The biocatalytic membrane reactor recorded more than 90% conversion, stable permeate flux with no enzyme leaching even after 5 cycles. The technique showing promising results to be expanded to continuous membrane separation setup for repeated use of enzymes.

Anaerobic oxidation of cholesterol by a denitrifying enrichment

2001 ◽  
Vol 44 (4) ◽  
pp. 145-150 ◽  
Author(s):  
E. Barrandeguy ◽  
S. Tarlera
Keyword(s):  
Anaerobic Treatment ◽  
Organic Load ◽  
Cholesterol Oxidation ◽  
Nitrite Accumulation ◽  
Reactor Performance ◽  
Nitrogen Gas ◽  
Carbon And Nitrogen ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
The One

Sterols (e.g. cholesterol) present in wool scouring effluent represent the most recalcitrant fraction in anaerobic treatment. This study was conducted to examine the feasibility of removal of this organic load through a denitrifying post-treatment stage. A stable cholesterol-denitrifying enrichment (CHOL-1) was obtained from sludge of a bench-scale upflow sludge bed (USB) denitrifying reactor integrated to a carbon and nitrogen removal system for sanitary landfill leachate. According to the amounts of cholesterol degraded and of nitrite and nitrogen gas formed, the capacity for complete cholesterol oxidation under anaerobic conditions by CHOL-1 can be assumed. Nitrite accumulation observed at a low C/N ratio outlines the importance of determining the optimal C/N ratio for adequate denitrifying reactor performance. The enrichment was partly identified with molecular analysis of cloned 16S rDNA sequences revealing the presence of two groups of bacteria belonging to the β subclass of the Proteobacteria. According to analysis of sequences, it can be inferred that a yet uncultivated new bacterium is the one responsible for cholesterol oxidation. Results of this study suggest that sludge from a denitrifying reactor treating leachate is potentially useful in a combined anaerobic-anoxic system for degradation of cholesterol that remains after methanogenic treatment.

Newly designed high-coverage degenerate primers for nitrogen removal mechanism analysis in a partial nitrification-anammox (PN/A) process

2019 ◽  
Vol 96 (1) ◽  
Author(s):  
Qingkun Wang ◽  
Jianzhong He
Keyword(s):  
Nitrogen Removal ◽  
Partial Nitrification ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Anammox Bacteria ◽  
Mechanism Analysis ◽  
Reactor Performance ◽  
Degenerate Primers ◽  
High Coverage ◽  
Nitrite Oxidizing Bacteria

ABSTRACT Reliable tools for quantification of different functional populations are required to achieve stable, effective nutrients removal in partial nitrification and anammox (PN/A) processes. Here we report the design and validation of degenerate PCR primer pairs targeting anammox bacteria, aerobic ammonium-oxidizing bacteria (AeAOB) and nitrite-oxidizing bacteria (NOB) with high coverage but without sacrificing specificity. The new primer pairs are able to cover a broader range of the targeted populations (58.4 vs 21.7%, 49.5 vs 47.6%, 80.7 vs 57.2% and 70.5 vs 42.3% of anammox bacteria, AeAOB, Nitrobacter and Nitrospina, respectively) than previously published primers. Particularly, the Amx719F/875R primer can retrieve a larger number of 16S rRNA genes from different types of samples with amplicons covering all known anammox bacteria genera (100% coverage) including the recently found novel genus, Asahi BRW. These newly desinged primers will provide a more reliable molecular tool to investigate the mechanisms of nitrogen removal in PN/A processes, which can provide clearer links between reactor performance, the metabolic activities and abundances of functional populations, shedding light on conditions that are favorable to the establishment of stable PN/A.

scholarly journals In Situ Activity and Spatial Organization of Anaerobic Ammonium-Oxidizing (Anammox) Bacteria in Biofilms

2007 ◽  
Vol 73 (15) ◽  
pp. 4931-4939 ◽  
Author(s):  
Tomonori Kindaichi ◽  
Ikuo Tsushima ◽  
Yuji Ogasawara ◽  
Masaki Shimokawa ◽  
Noriatsu Ozaki ◽  
...  
Keyword(s):  
Organic Compounds ◽  
Spatial Organization ◽  
Flow Direction ◽  
Anammox Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Reactor Performance ◽  
Inlet Port ◽  
Anammox Activity ◽  
Total Bacteria

ABSTRACT We investigated autotrophic anaerobic ammonium-oxidizing (anammox) biofilms for their spatial organization, community composition, and in situ activities by using molecular biological techniques combined with microelectrodes. Results of phylogenetic analysis and fluorescence in situ hybridization (FISH) revealed that “Brocadia”-like anammox bacteria that hybridized with the Amx820 probe dominated, with 60 to 92% of total bacteria in the upper part (<1,000 μm) of the biofilm, where high anammox activity was mainly detected with microelectrodes. The relative abundance of anammox bacteria decreased along the flow direction of the reactor. FISH results also indicated that Nitrosomonas-, Nitrosospira-, and Nitrosococcus-like aerobic ammonia-oxidizing bacteria (AOB) and Nitrospira-like nitrite-oxidizing bacteria (NOB) coexisted with anammox bacteria and accounted for 13 to 21% of total bacteria in the biofilms. Microelectrode measurements at three points along the anammox reactor revealed that the NH4 + and NO2 − consumption rates decreased from 0.68 and 0.64 μmol cm−2 h−1 at P2 (the second port, 170 mm from the inlet port) to 0.30 and 0.35 μmol cm−2 h−1 at P3 (the third port, 205 mm from the inlet port), respectively. No anammox activity was detected at P4 (the fourth port, 240 mm from the inlet port), even though sufficient amounts of NH4 + and NO2 − and a high abundance of anammox bacteria were still present. This result could be explained by the inhibitory effect of organic compounds derived from biomass decay and/or produced by anammox and coexisting bacteria in the upper parts of the biofilm and in the upstream part of the reactor. The anammox activities in the biofilm determined by microelectrodes reflected the overall reactor performance. The several groups of aerobic AOB lineages, Nitrospira-like NOB, and Betaproteobacteria coexisting in the anammox biofilm might consume a trace amount of O2 or organic compounds, which consequently established suitable microenvironments for anammox bacteria.

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