scholarly journals Evaluation of a Full-Scale Suspended Sludge Deammonification Technology Coupled with an Hydrocyclone to Treat Thermal Hydrolysis Dewatering Liquors

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 278
Author(s):  
Pascal Ochs ◽  
Benjamin D. Martin ◽  
Eve Germain ◽  
Zhuoying Wu ◽  
Po-Heng Lee ◽  
...  

Suspended sludge deammonification technologies are frequently applied for sidestream ammonia removal from dewatering liquors resulting from a thermal hydrolysis anaerobic digestion (THP/AD) process. This study aimed at optimizing the operation, evaluate the performance and stability of a full-scale suspended sludge continuous stirred tank reactor (S-CSTR) with a hydrocyclone for anaerobic ammonia oxidizing bacteria (AMX) biomass separation. The S-CSTR operated at a range of nitrogen loading rates of 0.08–0.39 kg N m−3 d−1 displaying nitrogen removal efficiencies of 75–89%. The hydrocyclone was responsible for retaining 56–83% of the AMX biomass and the washout of ammonia oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) was two times greater than AMX. The solid retention time (SRT) impacted on NOB washout, that ranged from 0.02–0.07 d−1. Additionally, it was demonstrated that an SRT of 11–13 d was adequate to wash-out NOB. Microbiome analysis revealed a higher AMX abundance (Candidatus scalindua) in the reactor through the action of the hydrocyclone. Overall, this study established the optimal operational envelope for deammonification from THP/AD dewatering liquors and the role of the hydrocyclone towards maintaining AMX in the S-CSTR and hence obtain process stability.

2012 ◽  
Vol 65 (3) ◽  
pp. 581-588 ◽  
Author(s):  
Naohiro Kishida ◽  
Goro Saeki ◽  
Satoshi Tsuneda ◽  
Ryuichi Sudo

In this study, the effectiveness of aerobic granular sludge as seed sludge for rapid start-up of nitrifying processes was investigated using a laboratory-scale continuous stirred-tank reactor (CSTR) fed with completely inorganic wastewater which contained a high concentration of ammonia. Even when a large amount of granular biomass was inoculated in the reactor, and the characteristics of influent wastewater were abruptly changed, excess biomass washout was not observed, and biomass concentration was kept high at the start-up period due to high settling ability of the aerobic granular sludge. As a result, an ammonia removal rate immediately increased and reached more than 1.0 kg N/m3/d within 20 days and up to 1.8 kg N/m3/d on day 39. Subsequently, high rate nitritation was stably attained during 100 days. However, nitrite accumulation had been observed for 140 days before attaining complete nitrification to nitrate. Fluorescence in situ hybridization analysis revealed the increase in amount of ammonia-oxidizing bacteria which existed in the outer edge of the granular sludge during the start-up period. This microbial ecological change would make it possible to attain high rate ammonia removal.


2018 ◽  
Author(s):  
Yingyu Law ◽  
Artur Matysik ◽  
Xueming Chen ◽  
Sara Swa Thi ◽  
Thi Quynh Ngoc Nguyen ◽  
...  

AbstractWe report that a singleNitrospirasublineage I OTU performs nitrite oxidation in several full-scale domestic wastewater treatment plants (WWTPs) in the tropics (29-31 °C). Contrary to the prevailing theory for the relationship between nitrite oxidizing bacteria (NOB) and ammonia oxidizing bacteria (AOB), members of theNitrospirasublineage I OTU had an apparent half saturation coefficient,Ks(app)lower than that of the full-scale domestic activated sludge cohabitant AOB (0.09 ± 0.02 g O2 m−3versus 0.3 ± 0.03 g O2 m−3). Paradoxically, NOB may thus thrive under conditions of low oxygen supply. Low dissolved oxygen (DO) conditions could enrich for and high aeration inhibit the NOB in a long-term lab-scale reactor. The relative abundance ofNitrospiragradually decreased with increasing DO until it was washed out. Nitritation was sustained even after the DO was lowered subsequently. Based on 3D-fluorescencein situhybridization (FISH) image analysis, the morphologies of AOB and NOB microcolonies responded to DO levels in accordance with their apparent oxygen half saturation constantKs(app). When exposed to the same oxygenation level, NOB formed densely packed spherical clusters with a low surface area-to-volume ratio compared to theNitrosomonas-like AOB clusters, which maintained a porous and non-spherical morphology. Microcolony morphology is thus a way for AOB and NOB to regulate oxygen exposure and sustain the mutualistic interaction. However, short-term high DO exposure can select for AOB and against NOB in full-scale domestic WWTPs and such population dynamics depend on which specific AOB and NOB species predominate under given environmental conditions.


2021 ◽  
Author(s):  
Katherine J Vilardi ◽  
Irmarie Cotto ◽  
Maria Sevillano Rivera ◽  
Zihan Dai ◽  
Christopher L Anderson ◽  
...  

Complete ammonia oxidizing bacteria coexist with canonical ammonia and nitrite oxidizing bacteria in a wide range of environments. Whether this coexistence is due to competitive or cooperative interactions between the three guilds, or a result of niche separation is not yet clear. Understanding the factors driving coexistence of nitrifying guilds is critical to effectively manage nitrification processes occurring in engineered and natural ecosystems. In this study, microcosms-based experiments were used to investigate the impact of electron donor mode (i.e., ammonia and urea) and loading on the population dynamics of nitrifying guilds in drinking water biofilter media. Shotgun sequencing of DNA from select time points followed by co-assembly and re-construction of metagenome assembled genomes (MAGs) revealed multiple clade A2 and one clade A1 comammox bacterial populations coexisted in the microcosms alongside Nitrosomonas-like ammonia oxidizers and Nitrospira-like nitrite oxidizer populations. Clade A2 comammox bacteria were likely the primary nitrifiers within the microcosms and increased in abundance over canonical ammonia and nitrite oxidizing bacteria irrespective of electron donor mode or nitrogen loading rates. This suggests that comammox bacteria will outnumber nitrifying communities sourced from oligotrophic environments irrespective of variable nitrogen regimes. Changes in comammox bacterial abundance were not correlated with either ammonia or nitrite oxidizing bacterial abundance in urea amended systems where metabolic reconstruction indicated potential cross feeding between ammonia and nitrite oxidizing bacteria. In contrast, comammox bacterial abundance demonstrated a negative correlation with that of nitrite oxidizers in ammonia amended systems. This suggests that potentially weaker synergistic relationships between ammonia and nitrite oxidizers might enable comammox bacteria to displace nitrite oxidizers from complex nitrifying communities.


2015 ◽  
Vol 73 (4) ◽  
pp. 761-768 ◽  
Author(s):  
Karol Trojanowicz ◽  
Elzbieta Plaza ◽  
Jozef Trela

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.


2003 ◽  
Vol 48 (8) ◽  
pp. 119-126 ◽  
Author(s):  
K.G. Robinson ◽  
H.M. Dionisi ◽  
G. Harms ◽  
A.C. Layton ◽  
I.R. Gregory ◽  
...  

Nitrification was assessed in two full-scale wastewater treatment plants (WWTPs) over time using molecular methods. Both WWTPs employed a complete-mix suspended growth, aerobic activated sludge process (with biomass recycle) for combined carbon and nitrogen treatment. However, one facility treated primarily municipal wastewater while the other only industrial wastewater. Real time PCR assays were developed to determine copy numbers for total 16S rDNA (a measure of biomass content), the amoA gene (a measure of ammonia-oxidizers), and the Nitrospira 16S rDNA gene (a measure of nitrite-oxidizers) in mixed liquor samples. In both the municipal and industrial WWTP samples, total 16S rDNA values were approximately 2-9 × 1013 copies/L and Nitrospira 16S rDNA values were 2-4 × 1010 copies/L. amoA gene concentrations averaged 1.73 × 109 copies/L (municipal) and 1.06 × 1010 copies/L (industrial), however, assays for two distinct ammonia oxidizing bacteria were required.


2018 ◽  
Vol 2018 (4) ◽  
pp. 321-328
Author(s):  
Todd O Williams ◽  
Peter Burrowes ◽  
Marialena Hatzigeorgiou

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Laibin Huang ◽  
Seemanti Chakrabarti ◽  
Jennifer Cooper ◽  
Ana Perez ◽  
Sophia M. John ◽  
...  

AbstractNitrification is a central process in the global nitrogen cycle, carried out by a complex network of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), complete ammonia-oxidizing (comammox) bacteria, and nitrite-oxidizing bacteria (NOB). Nitrification is responsible for significant nitrogen leaching and N2O emissions and thought to impede plant nitrogen use efficiency in agricultural systems. However, the actual contribution of each nitrifier group to net rates and N2O emissions remain poorly understood. We hypothesized that highly fertile agricultural soils with high organic matter mineralization rates could allow a detailed characterization of N cycling in these soils. Using a combination of molecular and activity measurements, we show that in a mixed AOA, AOB, and comammox community, AOA outnumbered low diversity assemblages of AOB and comammox 50- to 430-fold, and strongly dominated net nitrification activities with low N2O yields between 0.18 and 0.41 ng N2O–N per µg NOx–N in cropped, fallow, as well as native soil. Nitrification rates were not significantly different in plant-covered and fallow plots. Mass balance calculations indicated that plants relied heavily on nitrate, and not ammonium as primary nitrogen source in these soils. Together, these results imply AOA as integral part of the nitrogen cycle in a highly fertile agricultural soil.


Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 346
Author(s):  
Keugtae Kim ◽  
Yong-Gyun Park

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.


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