Tailoring of highly efficient nitrifying biofilms in fluidized bed for ammonia-rich industrial wastewater treatment

2000 ◽  
Vol 42 (3-4) ◽  
pp. 357-362 ◽  
Author(s):  
S. Tsuneda ◽  
T. Miyoshi ◽  
Y. Aoi ◽  
A. Hirata

We proposed two tailoring methods for efficient nitrifying biofilms on particles which are expected to be used in fluidized bed in nitrogen removal processes for industrial wastewaters. The first method was examined with gradual reduction of the hydraulic retention time in continuous feeding reactor to form biofilm with high nitrification ability. As a result, nitrification rate was successfully improved mainly due to acclimation of nitrifying bacteria to higher loading. The second tailoring method for nitrifying biofilm started with the biofilm which had been previously constructed in synthetic domestic wastewater containing high concentration of NH4+-N as well as various biodegradable organic compounds. Stepwise reduction of C/N ratio in inlet wastewater was performed during one month simultaneously with observation of microbial population dynamics in the biofilm using fluorescent in situ hybridization (FISH) analysis. As a result, this acclimation process promoted occupation of the biofilm by ammonia-oxidizing bacteria and resulted in making suitable biofilm structure for nitrification of ammonia-rich industrial wastewater. Moreover, it is confirmed that this new tailoring method greatly shortened required time to obtain nitrifying biofilms.

2018 ◽  
Vol 78 (8) ◽  
pp. 1704-1714 ◽  
Author(s):  
François-René Bourgeois ◽  
Frédéric Monette ◽  
Daniel G. Cyr

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.


2009 ◽  
Vol 60 (12) ◽  
pp. 3243-3251 ◽  
Author(s):  
Jianhua Guo ◽  
Shuying Wang ◽  
Huijun Huang ◽  
Yongzhen Peng ◽  
Shijian Ge ◽  
...  

Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite.


2013 ◽  
Vol 68 (9) ◽  
pp. 2035-2041 ◽  
Author(s):  
H. W. Sun ◽  
Y. Bai ◽  
Y. Z. Peng ◽  
H. G. Xie ◽  
X. N. Shi

In this study, a biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic–oxic (A/O) reactor was established for the advanced treatment of high ammonium urban landfill leachate. The inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on the nitrifying bacterial activity was used to achieve stable nitritation in the A/O reactor. The results demonstrated that the biological system achieved chemical oxygen demand (COD), total nitrogen (TN) and NH4+-N removal efficiencies of 95.3, 84.6 and 99.2%, respectively at a low carbon-to-nitrogen ratio of 3:1. Simultaneous denitritation and methanogenesis in the UASB could improve the removal of COD and TN. Nitritation with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Fluorescence in situ hybridization (FISH) analysis showed that ammonia oxidizing bacteria (AOB) was dominant and was considered to be responsible for the satisfactory nitritation performance.


1995 ◽  
Vol 31 (1) ◽  
pp. 185-193 ◽  
Author(s):  
Van T. Nguyen ◽  
Wen K. Shieh

Significant amounts of nitrogenous organic compounds found in industrial wastewaters can have major deleterious effects on the environment and public health; therefore, the removal of these compounds has become an essential component in industrial wastewater treatment. In this work the biodegradability of diisopropylamine and monoethylamine - compounds commonly found in petroleum refinery wastewater - was investigated under oxic and anoxic conditions. Biological fluidized bed reactors were employed in the investigation of single-stage carbon oxidation and nitrification with the amines and phenol as the compounds targeted for removal. Complete carbonaceous oxidation was achieved with a 50% nitrification rate. The feasibility of utilizing the amines and phenol as the organic carbon source for denitrification in an anoxic biological fluidized bed process was also examined. Carbon removal under anoxic conditions was greater than 85% at carbon loading rates less than 0.05 mg TOC/mg biomass-day and decreased to 60% at higher loading rates. Over the range of loading rates tested, the average ratio of mg TOC removed to mg NO3−-N utilized was observed to be 1.26.


2004 ◽  
Vol 49 (5-6) ◽  
pp. 333-340 ◽  
Author(s):  
D.J. Kim ◽  
T.K. Kim ◽  
E.J. Choi ◽  
W.C. Park ◽  
T.H. Kim ◽  
...  

Fluorescence in situ hybridization (FISH) was performed to analyze the nitrifying microbial communities in an activated sludge reactor (ASR) and a fixed biofilm reactor (FBR) for piggery wastewater treatment. Heterotrophic oxidation and nitrification were occurring simultaneously in the ASR and the COD and nitrification efficiencies depend on the loads. In the FBR nitrification efficiency also depends on ammonium load to the reactor and nitrite was accumulated when free ammonia concentration was higher than 0.2 mg NH3-N/L. FISH analysis showed that ammonia-oxidizing bacteria (NSO1225) and denitrifying bacteria (RRP1088) were less abundant than other bacteria (EUB338) in ASR. Further analysis on nitrifying bacteria in the FBR showed that Nitrosomonas species (NSM156) and Nitrospira species (NSR1156) were the dominant ammonia-oxidizing and nitrite-oxidizing bacteria, respectively, in the piggery wastewater nitrification system.


2004 ◽  
Vol 49 (11-12) ◽  
pp. 99-105 ◽  
Author(s):  
S. Tarre ◽  
M. Beliavski ◽  
N. Denekamp ◽  
A. Gieseke ◽  
D. de Beer ◽  
...  

A typical steady state bulk pH of about 5 was established in a nitrifying fluidized bed with chalk as the only buffer agent. In spite of the low pH, high rate nitrification was observed with the nitrification kinetic parameters in the chalk reactor similar to those of biological reactors operating at pH>7. Various methods were used to determine the reasons for high rate nitrification at such low pH including (i) determination of bacterial species, (ii) microsensor measurements in the biofilm, and (iii) comparison of nitrification performance at low pH with a non-chalk fluidized bed reactor. Fluorescence in situ hybridization (FISH) using existing 16S rRNA-targeted oligonucleotide probes showed common nitrifying bacteria in the low pH chalk reactor. The prevalent nitrifying bacteria were identified in the Nitrosomonas oligotropha, Nitrosomonas europeae/eutropha, Nitrosospira and Nitrospira related groups, all well known nitrifiers. Microelectrode measurements showed that the pH in the biofilm was low and similar to that of the bulk pH. Finally, reactor performance using a non-chalk biofilm carrier (sintered glass) with the same bacterial inoculum also showed high rate nitrification below pH 5. The results suggest that inhibition of nitrification at low pH is highly overestimated.


2018 ◽  
Vol 156 (2) ◽  
pp. 215-224
Author(s):  
Santosh Ranjan Mohanty ◽  
Rakhi Yadav ◽  
Garima Dubey ◽  
Usha Ahirwar ◽  
Neha Ahirwar ◽  
...  

AbstractNitrification potential of a tropical vertisol saturated with water was estimated during sequential reduction of nitrate (NO3−), ferric iron (Fe3+), sulphate (SO42−) and carbon dioxide (CO2) in terminal electron-accepting processes (TEAPs). In general, the TEAPs enhanced potential nitrification rate (PNR) of the soil. Nitrification was highest at Fe3+reduction followed by SO42−reduction, NO3−reduction and lowest in unreduced control soil. Predicted PNR correlated significantly with the observed PNR. Electron donor Fe2+stimulated PNR, while S2−inhibited it significantly. Terminal-restriction fragment length polymorphism targeting theamoAgene of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) highlighted population dynamics during the sequential reduction of terminal electron acceptors. Only the relative abundance of AOA varied significantly during the course of soil reduction. Relative abundance of AOB correlated with NO3−and Fe2+. Linear regression models predicted PNR from the values of NO3−, Fe2+and relative abundance of AOA. Principal component analysis of PNR during different reducing conditions explained 72.90% variance by PC1 and 19.52% variance by PC2. Results revealed that AOA might have a significant role in nitrification during reducing conditions in the tropical flooded ecosystem of a vertisol.


2004 ◽  
Vol 49 (11-12) ◽  
pp. 27-34 ◽  
Author(s):  
S. Tsuneda ◽  
Y. Ejiri ◽  
T. Nagano ◽  
A. Hirata

The influences of trace metals in the wastewater and shear stress by aeration were particularly examined to clarify the formation mechanism of nitrifying granules in an aerobic upflow fluidized bed (AUFB) reactor. It was found that Fe added as a trace element to the inorganic wastewater accumulated at the central part of the nitrifying granules. Another result obtained was that suitable shear stress by moderate aeration (0.07-0.20 L/min/L-bed) promoted granulation. Furthermore, it was successfully demonstrated that pre-aggregation of seed sludge using hematite promoted core formation, leading to rapid production of nitrifying granules. From these results, a nitrifying granulation mechanism is proposed: 1) as a first step, nitrifying bacteria aggregate along with Fe precipitation, and then the cores of granules are formed; 2) as a second step, the aggregates grow to be spherical or elliptical in form due to multiplication of the nitrifying bacteria and moderate shear stress in the reactor, and then mature nitrifying granules are produced. Fluorescence in situ hybridization (FISH) analysis successfully visualized the change in the spatial distribution of nitrifying bacteria in the granules, which supports the proposed granulation mechanism.


2013 ◽  
Vol 67 (5) ◽  
pp. 1083-1091 ◽  
Author(s):  
X. M. Hu ◽  
Y. W. Chen ◽  
Y. G. Liao ◽  
W. F. Yan ◽  
S. M. Zhu ◽  
...  

In this experiment, a rapid mass-transfer inner loop fluidized bed biofilm reactor (ILFBBR) was employed to treat synthetic high ammonia nitrogen-containing (NH4+-N) wastewater by shortcut nitrification–denitrification. The reactor operation was stable after a short start-up period. Ammonia oxidizing bacteria (AOB) were predominant and 65% nitrite (NO2−-N/NOx−-N) levels were achieved. During the nitrification–denitrification period, the removal rates of NH4+-N and total nitrogen (TN) reached 94 and 82%, respectively. From the material balance, it was indicated that 87% of NH4+-N was removed by shortcut nitrification. The features of ILFBBR and the benefits of shortcut nitrification were combined in this experiment, and showed an excellent removal of NH4+-N from high-concentration NH4+-N wastewater.


2000 ◽  
Vol 42 (12) ◽  
pp. 21-32 ◽  
Author(s):  
S. Okabe ◽  
Y. Watanabe

Time dependent development of the spatial organization of NH4+- and NO2−-oxidizing bacterial populations in a domestic wastewater biofilm and in an autotrophic nitrifying biofilm were investigated by fluorescent in situ hybridization (FISH) with a set of 16S rRNA-targeted oligonucleotide probes. Population dynamics of nitrifying bacteria in the biofilms were correlated with the biofilm performance. In situ hybridization indicated that Nitrosomonas spp. (excluding probe NEU stained NH4+-oxidizing bacteria: i.e., N. marina-lineage, N. europaea-lineage, N. eutropha, and N. halophila) and Nitrospira-like bacteria were the numerically dominant nitrifying species in the domestic wastewater biofilm. However, probe NEU stained NH4+-inoxidizing bacteria became dominant populations in the autotrophic nitrifying biofilm (which were initially cultured with the primary settling tank effluent) after switching to the synthetic media. This population shift might be attributed to the effect of NO2−-–N accumulation and higher growth rates of N. europaea-lineage and N. eutropha, outcompeting other Nitrosomonas spp. in the synthetic medium. This evidence indirectly supports that N. europhaea has been most commonly isolated and studied in most of the previous researches. For the spatial organization of NH4+- and NO2−-oxidizing bacterial populations, bacteria of the genus Nitrobacter could not be detected, instead Nitrospira-like bacteria were found as the main nitrite-oxidizing bacteria in both biofilms. Whereas most of the ammonia-oxidizing bacteria were found throughout the biofilms, the location of nitrite-oxidizing bacteria was restricted to the active nitrite-oxidizing zone, which was detected in the inner part of the biofilms. Microelectrode measurements showed that the active ammonia-oxidizing zone was located in the outer part of a biofilm, whereas the active nitrite-oxidizing zone was located just below the ammonia-oxidizing zone and overlapped the location of NO2−-oxidizing bacteria, as determined with FISH. These observations have considerable significance to our understanding of microbial nitrification occurring in wastewater treatment processes and in the natural environment.


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