scholarly journals Biomass segregation between biofilm and flocs improves the control of nitrite-oxidizing bacteria in mainstream partial nitritation and anammox processes

2018 ◽  
Author(s):  
Michele Laureni ◽  
David G. Weissbrodt ◽  
Kris Villez ◽  
Orlane Robin ◽  
Nadieh de Jonge ◽  
...  
Keyword(s):  
Growth Rates ◽  
Municipal Wastewater ◽  
Biofilm Reactor ◽  
Operating Conditions ◽  
Anammox Bacteria ◽  
List Type ◽  
Operational Flexibility ◽  
Partial Nitritation ◽  
Nitrite Oxidizing Bacteria ◽  
Actual Growth

AbstractThe control of nitrite-oxidizing bacteria (NOB) challenges the implementation of partial nitritation and anammox (PN/A) processes under mainstream conditions. The aim of the present study was to understand how operating conditions impact microbial competition and the control of NOB in hybrid PN/A systems, where biofilm and flocs coexist. A hybrid PN/A moving-bed biofilm reactor (MBBR; also referred to as integrated fixed film activated sludge or IFAS) was operated at 15 °C on aerobically pre-treated municipal wastewater (23 mgNH4-N·L−1). Ammonium-oxidizing bacteria (AOB) and NOB were enriched primarily in the flocs, and anammox bacteria (AMX) in the biofilm. After decreasing the dissolved oxygen concentration (DO) from 1.2 to 0.17 mgO2·L−1 - with all other operating conditions unchanged - washout of NOB from the flocs was observed. The activity of the minor NOB fraction remaining in the biofilm was suppressed at low DO. As a result, low effluent NO3− concentrations (0.5 mgN·L−1) were consistently achieved at aerobic nitrogen removal rates (80 mgN·L−1·d−1) comparable to those of conventional treatment plants. A simple dynamic mathematical model, assuming perfect biomass segregation with AOB and NOB in the flocs and AMX in the biofilm, was able to qualitatively reproduce the selective washout of NOB from the flocs in response to the decrease in DO-setpoint. Similarly, numerical simulations indicated that flocs removal is an effective operational strategy to achieve the selective washout of NOB. The direct competition for NO2− between NOB and AMX - the latter retained in the biofilm and acting as a “NO2-sink” - was identified by the model as key mechanism leading to a difference in the actual growth rates of AOB and NOB (i.e., μNOB < μAOB in flocs) and allowing for the selective NOB washout. Experimental results and model predictions demonstrate the increased operational flexibility, in terms of variables that can be easily controlled by operators, offered by hybrid systems as compared to solely biofilm systems for the control of NOB in mainstream PN/A applications.HighlightsHybrid PN/A systems provide increased operational flexibility for NOB controlAOB and NOB enrich primarily in the flocs, and AMX in the biofilm (“NO2-sink”)AMX use NO2− allowing to differentiate AOB and NOB growth ratesA decrease in DO or an increase in floc removal leads to selective NOB washout from flocsThe activity of the minor NOB fraction in the biofilm is suppressed at limiting DO

Pilot scale studies on nitritation-anammox process for mainstream wastewater at low temperature

2015 ◽  
Vol 73 (4) ◽  
pp. 761-768 ◽  
Author(s):  
Karol Trojanowicz ◽  
Elzbieta Plaza ◽  
Jozef Trela
Keyword(s):  
Low Temperature ◽  
Pilot Scale ◽  
Nitrogen Loading ◽  
Biofilm Reactor ◽  
Process Efficiency ◽  
Anammox Bacteria ◽  
Ammonia Oxidizing Bacteria ◽  
Partial Nitritation ◽  
Nitrite Oxidizing Bacteria ◽  
Anammox Process

Process of partial nitritation-anammox for mainstream wastewater at low temperature was run in a pilot scale moving bed biofilm reactor (MBBR) system for about 300 days. The biofilm history in the reactor was about 3 years of growth at low temperature (down to 10 °C). The goal of the studies presented in this paper was to achieve effective partial nitritation-anammox process. Influence of nitrogen loading rate, hydraulic retention time, aeration strategy (continuous versus intermittent) and sludge recirculation (integrated fixed-film activated sludge (IFAS) mode) on deammonification process' efficiency and microbial activity in the examined system was tested. It was found that the sole intermittent aeration strategy is not a sufficient method for successful suppression of nitrite oxidizing bacteria in MBBR. The best performance of the process was achieved in IFAS mode. The highest recorded capacity of ammonia oxidizing bacteria and anammox bacteria in biofilm was 1.4 gN/m2d and 0.5 gN/m2d, respectively, reaching 51% in nitrogen removal efficiency.

scholarly journals Úsporné odstraňování dusíku procesem anammox z kalových a splaškových odpadních vod

Entecho ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
Vojtěch Kouba ◽  
Jan Bartáček
Keyword(s):  
Nitrogen Removal ◽  
Low Temperatures ◽  
Municipal Wastewater ◽  
Pilot Scale ◽  
Main Stream ◽  
Excess Sludge ◽  
Partial Nitritation ◽  
Loading Rates ◽  
Reject Water ◽  
Nitrite Oxidizing Bacteria

Proces částečná nitritace-anammox odstraňuje amoniakální dusík z odpadních vod s polovičními náklady na aeraci, až o 80 % nižší produkcí přebytečného kalu a bez spotřeby organického substrátu. Jde o zavedený proces pro odstraňování dusíku z kalových vod z anaerobní fermentace, a podobně koncentrovaných a teplých odpadních vod. Na tyto vody se částečná nitritace-anammox aplikuje již déle než deset let, a to např. pod názvy ANAMMOX®, ANITA™ Mox, DEMON®, nebo TERRAMOX®. Optimalizované provozy těchto technologií dusík běžně odstraňují při zatížení 0,5–2,3 kg∙m–3∙d–1 (30–35 °C). Současnou výzvou pro výzkum je implementace částečné nitritace-anammox do hlavního proudu studené splaškové odpadní vody, přičemž konkrétními problémy jsou (i) potlačení nežádoucích nitratačních mikroorganismů (NOB) a (ii) adaptace mikroorganismů anammox na nízké teploty. Náš výzkum jsme začali s jednostupňovým procesem, a poté nitritaci a anammox rozdělili do dvou reaktorů. Prezentujeme strategii, která v laboratorním měřítku NOB účinně potlačila i při 12 °C a dále i v pilotním měřítku při 13–30 °C. Dále ukazujeme, že anammox je možné na nízké teploty adaptovat studenými šoky. Tyto výsledky umožní rozšířit úsporné odstraňování dusíku i do hlavního proudu splaškové odpadní vody na ČOV. English: Partial nitritation-anammox (PN/A) process removes nitrogen from wastewater with 50% reduction of aeration costs, 80% less excess sludge and no consumption of organic carbon. PN/A is an established process for the removal of nitrogen from reject water from anaerobic digestion and other similarly warm and concentrated streams. On such wastewater, PN/A has been applied in full scale for over 10 years under names such as ANAMMOX®, ANITA™ Mox, DEMON® or TERRAMOX®, whose optimized installations consistently achieve nitrogen removal loading rates of 0,5–2,3 kg∙m–3∙d–1. The current challenge for research is to implement PN/A into the main stream of cold municipal wastewater, the specific challenges being (i) suppression of undesirable nitrite oxidizing bacteria (NOB) and (ii) adaptation of anammox microorganisms to low temperatures. Our initial experiences with one-stage PN/A in the main stream led us to the separation of PN/A in two subsequent reactors. Subsequently, we developed a strategy for NOB suppression in partial nitritation even under 12 °C, which we then successfully tested in the pilot scale. Furthermore, we found that anammox can be adapted to low temperatures using cold shocks. In sum, these results will enable extending the savings for nitrogen removal into the main stream of wastewater at WWTP.

The impact of influent total ammonium nitrogen concentration on nitrite-oxidizing bacteria inhibition in moving bed biofilm reactor

2013 ◽  
Vol 69 (6) ◽  
pp. 1227-1233 ◽  
Author(s):  
Vojtech Kouba ◽  
Michael Catrysse ◽  
Hana Stryjova ◽  
Ivana Jonatova ◽  
Eveline I. P. Volcke ◽  
...  
Keyword(s):  
Municipal Wastewater ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Biofilm Reactor ◽  
Nitrite Accumulation ◽  
Municipal Wastewater Treatment ◽  
Moving Bed ◽  
Nitrite Oxidizing Bacteria ◽  
Total Ammonium ◽  
The Impact

The application of nitrification–denitrification over nitrite (nitritation–denitritation) with municipal (i.e. diluted and cold (or low-temperature)) wastewater can substantially improve the energy balance of municipal wastewater treatment plants. For the accumulation of nitrite, it is crucial to inhibit nitrite-oxidizing bacteria (NOB) with simultaneous proliferation of ammonium-oxidizing bacteria (AOB). The present study describes the effect of the influent total ammonium nitrogen (TAN) concentration on AOB and NOB activity in two moving bed biofilm reactors operated as sequencing batch reactors (SBR) at 15 °C (SBR I) and 21 °C (SBR II). The reactors were fed with diluted reject water containing 600, 300, 150 and 75 mg TAN L−1. The only factor limiting NOB activity in these reactors was the high concentrations of free ammonia and/or free nitrous acid (FNA) during the SBR cycles. Nitrite accumulation was observed with influents containing 600, 300 and 150 mg TAN L−1 in SBR I and 600 and 300 in SBR II. Once nitrate production established in the reactors, the increase of influent TAN concentration up to the original 600 mg TAN L−1 did not limit NOB activity. This was due to the massive development of NOB clusters throughout the biofilm that were able to cope with faster formation of FNA. The results of the fluorescence in situ hybridization analysis preliminarily showed the stratification of bacteria in the biofilm.

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 &gt;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.

scholarly journals Effects of carbon sources, COD/NO2−-N ratios and temperature on the nitrogen removal performance of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm

2017 ◽  
Vol 75 (7) ◽  
pp. 1712-1721 ◽  
Author(s):  
Zhaoming Zheng ◽  
Yun Li ◽  
Jun Li ◽  
Yanzhuo Zhang ◽  
Wei Bian ◽  
...  
Keyword(s):  
Carbon Source ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Inorganic Nitrogen ◽  
Carbon Sources ◽  
Biofilm Reactor ◽  
Partial Nitrification ◽  
Anammox Bacteria ◽  
Coupling Process ◽  
Anammox Activity

The aim of the present work was to evaluate the effects of carbon sources and chemical oxygen demand (COD)/NO2−-N ratios on the anammox–denitrification coupling process of the simultaneous partial nitrification, anammox and denitrification (SNAD) biofilm. Also, the anammox activities of the SNAD biofilm were investigated under different temperature. Kaldnes rings taken from the SNAD biofilm reactor were operated in batch tests to determine the nitrogen removal rates. As a result, with the carbon source of sodium acetate, the appropriate COD/NO2−-N ratios for the anammox–denitrification coupling process were 1 and 2. With the COD/NO2−-N ratios of 1, 2, 3, 4 and 5, the corresponding NO2−-N consumption via anammox was 87.1%, 52.2%, 29.3%, 23.7% and 16.3%, respectively. However, with the carbon source of sodium propionate and glucose, the anammox bacteria was found to perform higher nitrite competitive ability than denitrifiers at the COD/NO2−-N ratio of 5. Also, the SNAD biofilm could perform anammox activity at 15 °C with the nitrogen removal rate of 0.071 kg total inorganic nitrogen per kg volatile suspended solids per day. These results indicated that the SNAD biofilm process might be feasible for the treatment of municipal wastewater at normal temperature.

Influence of seasonal temperature fluctuations on two different partial nitritation-anammox reactors treating mainstream municipal wastewater

2015 ◽  
Vol 72 (8) ◽  
pp. 1358-1363 ◽  
Author(s):  
Susanne Lackner ◽  
Samuel Welker ◽  
Eva M. Gilbert ◽  
Harald Horn
Keyword(s):  
Municipal Wastewater ◽  
Batch Reactor ◽  
High Energy ◽  
Biofilm Reactor ◽  
Ex Situ ◽  
Nitrite Accumulation ◽  
Seasonal Temperature ◽  
Partial Nitritation ◽  
Conversion Rates ◽  
Anammox Activity

Partial nitritation-anammox (PN-A) has gained increasing interest for municipal wastewater treatment in recent years due to its high energy-saving potential. Moving the PN-A technology from side- to mainstream exhibited a set of challenges. Conditions are quite different, with much lower ammonium concentrations and temperatures. Biomass retention becomes highly important due to the even lower growth rates. This study compared two laboratory-scale reactors, a sequencing batch reactor (SBR) and a moving bed biofilm reactor (MBBR), employing realistic seasonal temperature variations over a 1-year period. The results revealed that both systems had to face decreasing ammonium conversion rates and nitrite accumulation at temperatures lower than 12°C. The SBR did not recover from the loss in anammox activity even when the temperature increased again. The MBBR only showed a short nitrite peak and recovered its initial ammonium turnover when the temperature rose back to &gt;15°C. The SBR had higher biomass specific rates, indicating that suspended sludge is less diffusion-limited but also more susceptible to biomass wash-out. However, the MBBR showed the more stable performance also at low temperatures and managed to recover. Ex situ batch activity tests supported reactor operation data by providing additional insight with respect to specific biomass activities.

scholarly journals Diversity and gene expression patterns of functional groups in sidestream and mainstream wastewater partial-nitritation anammox biofilms

2020 ◽  
Author(s):  
Carolina Suarez ◽  
David Gustavsson ◽  
Malte Hermansson ◽  
Frank Persson
Keyword(s):  
Functional Groups ◽  
Nitrogen Removal ◽  
Municipal Wastewater ◽  
Expression Patterns ◽  
Microbial Community Composition ◽  
Amplicon Sequencing ◽  
Ammonium Concentration ◽  
Anaerobic Sludge ◽  
Anammox Bacteria ◽  
Partial Nitritation

AbstractPartial nitritation-anammox (PNA) is today used for nitrogen removal from highly concentrated wastewater after anaerobic sludge digestion (sidestream). However, implementation of PNA for treatment of municipal wastewater (mainstream), with its lower ammonium concentration and lower temperature is challenging, which might be due to differences in microbial community composition and/or activity. To investigate this, we compared side-by-side sidestream and mainstream PNA biofilms using amplicon sequencing of 16S rDNA and rRNA, hzsB DNA and mRNA, and the genes nxrB, and amoA. The two communities were different to each other with relatively more heterotrophic denitrifying bacteria and less anammox bacteria in the mainstream. With hzsB and nxrB we found microdiversity among Brocadia and Nitrospira, and turnover (taxa replacement) between sidestream and mainstream. However, in both environments Brocadia sapporoensis represented most of the hzsB DNA and mRNA reads, despite the different environmental conditions and nitrogen removal rates. All of those populations present in both sidestream and mainstream had no differences in their 16S rRNA:rDNA ratios, supporting recent findings that rRNA:rDNA ratios are poor indicators of bacterial activity. The observed diversity within functional groups and composition differences between sidestream and mainstream add complexity to our view of PNA communities with possible implication for reactor function.

Development of single-stage nitrogen removal using anammox and partial nitritation (SNAP) and its treatment performances

2006 ◽  
Vol 53 (6) ◽  
pp. 83-90 ◽  
Author(s):  
K. Furukawa ◽  
P.K. Lieu ◽  
H. Tokitoh ◽  
T. Fujii
Keyword(s):  
Nitrogen Removal ◽  
Laser Scanning ◽  
Dna Analysis ◽  
Experimental Studies ◽  
Biofilm Reactor ◽  
Single Stage ◽  
Confocal Laser ◽  
Anammox Bacteria ◽  
Partial Nitritation ◽  
Operational Conditions

Single-stage Nitrogen removal using Anammox and Partial nitritation (SNAP) process was newly developed as an economical nitrogen removal process for ammonium rich wastewaters. The experimental studies for the evaluation of SNAP process were carried out using a novel biofilm reactor, in which hydrophilic net-type acryl fiber biomass carrier was applied. This SNAP reactor was operated under operational conditions of pH 7.5–7.7, 35 °C and DO 2–3 mg/L, and 60 to 80% of influent NH4-N was removed under loading rate of 0.48 kg-N/m3/d. Through the DNA analysis of the attached sludge, it was made clear that ammonium oxidizing bacteria (AOB) and anammox bacteria coexisted in the attach-immobilized sludge on the acryl fiber biomass carrier. Favorable conditions for the growth of anammox bacteria were created inside attach-immobilized nitrifying sludge. Two kinds of anammox bacteria and two kinds of AOB were detected in the SNAP sludge. Existence ratios of anammox and AOB were estimated to be 15% and 8.7%, respectively, based on the obtained clone numbers. This coexisting condition was confirmed by the FISH image of SNAP sludge and its confocal laser scanning microscope.

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