Spatial distribution of heterotrophs and nitrifiers in a submerged biofilter for nitrification

Fdz‐Polanco, F.; Méndez, Eduardo; Urueña, M. A.; Villaverde, S.; Garcı́a, Pilar Garcı́a

doi:10.1016/s0043-1354(00)00159-7

Cited by 119 publications

(59 citation statements)

References 18 publications

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“…Several previous investigations of mixed biofilm communities of heterotrophic and nitrifying bacteria from wastewater treatment have demonstrated competition for space and O 2 between these two groups of microorganisms (12,35,51). Due to significantly lower specific growth rate and dependency on O 2 , the nitrifiers can establish persistent populations only in biofilm strata where the heterotrophs are limited by substrate and not by O 2 .…”

Section: Resultsmentioning

confidence: 98%

Distribution and Rate of Microbial Processes in an Ammonia-Loaded Air Filter Biofilm

Juhler

Revsbech

Schramm

et al. 2009

Appl Environ Microbiol

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The in situ activity and distribution of heterotrophic and nitrifying bacteria and their potential interactions were investigated in a full-scale, two-section, trickling filter designed for biological degradation of volatile organics and NH 3 in ventilation air from pig farms. The filter biofilm was investigated by microsensor analysis, fluorescence in situ hybridization, quantitative PCR, and batch incubation activity measurements. In situ aerobic activity showed a significant decrease through the filter, while the distribution of ammonia-oxidizing bacteria (AOB) was highly skewed toward the filter outlet. Nitrite oxidation was not detected during most of the experimental period, and the AOB activity therefore resulted in NO 2 ؊ , accumulation, with concentrations often exceeding 100 mM at the filter inlet. The restriction of AOB to the outlet section of the filter was explained by both competition with heterotrophic bacteria for O 2 and inhibition by the protonated form of NO 2 ؊ , HNO 2 . Product inhibition of AOB growth could explain why this type of filter tends to emit air with a rather constant NH 3 concentration irrespective of variations in inlet concentration and airflow.Emissions of NH 3 , odorous organic gasses, and dust from pig facilities cause significant problems for neighbors and the surrounding natural environment. In Denmark, swine production accounts for 34% of the total atmospheric NH 3 emission, of which 50% originates from pig house emissions (19). Furthermore, multiple volatile and very odorous organic compounds are emitted with animal house exhaust air and constitute a severe nuisance in residential areas (16,31). While biofilters based on wood chips, compost, and peat have proven efficient in removing complex mixtures of volatile organic compounds (VOC) from piggery exhaust air, biotrickling filters have been shown to be efficient in both odor and NH 3 removal (30). In these filters, airborne VOC and NH 3 are taken up by an irrigated biofilm and oxidized by organoheterotrophic and nitrifying bacteria, respectively, resulting in the production of CO 2 , NO 2 Ϫ or NO 3 Ϫ , and microbial biomass (43). The nitrification process, which comprises the two-step oxidation of NH 3 via NO 2 Ϫ to NO 3 Ϫ , is catalyzed by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea and by nitriteoxidizing bacteria (NOB), respectively (22, 23). However, in many biotrickling filters, NOB activity seems to be absent, resulting in NO 2 Ϫ being the end product of nitrification (29). Waste products often accumulate in biotrickling filters, as the water is recycled many times to minimize wastewater discharge. In particular, NO 2 Ϫ may accumulate to concentrations above 100 mM (29), resulting in high levels of free nitrous acid (FNA, or HNO 2 ), which is inhibitory to many microorganisms (2, 40, 50). As a result of an overall countercurrent air-water flow, FNA, VOC, and NH 3 concentrations are expected to decrease from the filter air inlet toward the outlet, potentially promoting a gradient of microbial p...

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Section: Resultsmentioning

confidence: 98%

Distribution and Rate of Microbial Processes in an Ammonia-Loaded Air Filter Biofilm

Juhler

Revsbech

Schramm

et al. 2009

Appl Environ Microbiol

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“…The carbon loading used in this part of study, 5.71 ±0.16 kg COD/m 3 .d, was much higher than the loadings used by Wijeyekoon (Table 9.4), and therefore nitrifiers were not only displaced further away from the feed source, but also buried deeper into the biofilm (Ohashi et al 1995). Fdz-Polanco et al (2000) also observed that as the amount of organic carbon entering the filter increases, the nitrification activity is displaced to the upper part of the filter in an upflow process. Quyang et al (2000) also argued that the differences in biological activity at different filter heights were due to their varying loadings.…”

Section: Glass Beads Concentrations (G/l)mentioning

confidence: 66%

“…The denitrification process may also be disrupted because the biofilm provides potential anaerobic conditions in which denitrification flourishes. Fdz-Polanco et al (2000) pointed out the importance of understanding the spatial distribution of the microbial population, and its activity, for the optimisation of nitrogen removal performance in reactors treating wastewater. The performance of the full and partial-bed reactors for nitrogen removal has been examined (Fatihah 2004).…”

Section: Introductionmentioning

confidence: 99%

Detection of Ammonia-oxidizing Bacteria (AOB) in the Biofilm and Suspended Growth Biomass of Fully- and Partially-packed Biological Aerated Filters

Sujá¹

2011

Biomass - Detection, Production and Usage

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“…In the biofilm processes, it could maintain a high cellular retention time, even at low HRT [27], and then nitrobacteria would be able to multiply. When the ratios of COD : NH þ 4 -N were fairly low (i.e., lower than 4 [28]), nitrobacteria would become the prevalent microbes in the biofilm. Consequently, nitrification would occur.…”

Section: Organic Loadingmentioning

confidence: 99%

Comparison and modeling of two biofilm processes applied to decentralized wastewater treatment

Qiu

Liu

Song

et al. 2009

Front. Environ. Sci. Eng. China

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In order to control water pollution in the rapidly urbanizing South China area, biological contact oxidation (BCO) process and biological aerated filter (BAF) process were applied in a pilot-scale experiment for decentralized wastewater treatment. An investigation to find the optimal parameters of the two biofilm systems was conducted on hydraulic loading, organic loading, and aeration rate. The results indicated that the water reuse criteria required a maximum hydraulic and organic loading of 30.0 m 3 /(m 2 $d) and 4.0 kg COD/(m 3 $d), respectively, as well as a minimum effluent DO of 4.0 mg/L. The utilization of a new media allowed BAF to perform better than BCO. The kinetic description of the COD removal process for BAF and BCO are S e ¼ S 0 e -0:639t =ð1 þ 1:035tÞ, and S e ¼ S 0 =½ð1 þ 0:947tÞð1 þ 1:242tÞ, respectively. The correlativity analysis showed that the two models could predict the effluent water quality based on the hydraulic retention time. Thus, the appropriate hydraulic loading for certain effluent water quality demands could be determined. The two models could be applied to wastewater treatment practice.

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Spatial distribution of heterotrophs and nitrifiers in a submerged biofilter for nitrification

Cited by 119 publications

References 18 publications

Distribution and Rate of Microbial Processes in an Ammonia-Loaded Air Filter Biofilm

Distribution and Rate of Microbial Processes in an Ammonia-Loaded Air Filter Biofilm

Detection of Ammonia-oxidizing Bacteria (AOB) in the Biofilm and Suspended Growth Biomass of Fully- and Partially-packed Biological Aerated Filters

Comparison and modeling of two biofilm processes applied to decentralized wastewater treatment

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