Simultaneous Nitrification and Denitrification in Micro-Aerobic Biofilms

Watanabe, Yoshimasa; Masuda, Sumio; Ishiguro, Masayoshi

doi:10.2166/wst.1992.0431

Cited by 56 publications

(11 citation statements)

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“…The effects of raw sewage C/N ratio variations in small community WWTPs are highlighted in [8][9][10], which also show the possible negative side effects of dissolved oxygen accumulation in the denitrification stage. In addition, in 2006, in a Life project, the EU emphasized the effects of sharp fluctuations in the quality of raw sewage on the efficiency of biological processes [11].…”

Section: Open Accessmentioning

confidence: 99%

Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)

2013

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Abstract:The great diurnal variation in the quality of wastewater of small communities is an obstacle to the efficient removal of high nitrogen with traditional activated sludge processes provided by pre-denitrification. To verify this problem, the authors developed a pilot plant, in which the domestic wastewater of community of 15,000 inhabitants was treated. The results demonstrate that average and peak nitrogen removal efficiencies of over 60% and 70%, respectively, are difficult to obtain because of the strong variations in the BOD 5 /NO 3 -N ratios and the unexpected abnormal accumulation of dissolved oxygen during denitrification when the BOD 5 load is low. These phenomena cause inhibitory effects and BOD 5 deficiency in the denitrification process. The results demonstrate the need for a more complex approach to designing and managing small wastewater treatment plants (WWTPs) provided with denitrification than those usually adopted for medium-and large-size plants.

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Section: Open Accessmentioning

confidence: 99%

Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)

2013

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“…In this way, their growth was attributed to soluble microbial products release by autotrophic. (Watanebe et al, 1992;Rittmann and Snoeyink, 1984). From these values, it can be observed that heterotrophic bacteria present a high growth rate in relation to nitrifying autotrophic.…”

Section: Heterotrophic Bacteriamentioning

confidence: 95%

Nitrifying, Denitrifying and Heterotrophic Biomass Present in Moving Bed-Reactor

Oliveira¹,

Correa²,

Prates³

et al. 2017

American Journal of Environmental Sciences

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This study was carried out to evaluate the main bacterial communities related to the removal of nitrogen in a moving bed-reactor treating landfill leachate, relating the physico-chemical parameters with the existence of these organisms in the mixed liquor (non-attached microorganisms) and Support Material (SM). The system was operated in two phases: Phase I (without effluent recirculation) and II (with recirculation, at a flow rate of 3 times the inlet flow). To monitor the system, physico-chemical analyzes were determined in the influent and effluent: pH, alkalinity, temperature, nitrogen species, Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD). To determine the concentration of nitrifying bacteria (Ammonia Oxidizing Bacteria-AOB and Nitrite Oxidizing Bacteria-NOB) and denitrifiers, the most probable number was estimated per 100 mL (MPN.100 mL −1 ). The concentration of heterotrophic bacteria was estimated by determination of colony forming unit per mL (CFU.mL −1 ). The reactor showed a high percentage of NH 4 + -N removal in both phases of operation, reaching 80% removal efficiency in Phase I and 83% in II. At pH close to 5.4 NOB activity was practically ceased, with nitrite accumulation in the system. Although the oxygen concentration in the mixed liquor was above 2.0 mg.L −1 the concentration of denitrifying bacteria was not affected. The concentration of heterotrophic bacteria was above 10 9 CFU.mL −1 , but COD removal in the system was low due to low BOD/COD ratio in the mixed liquor. Analyzing the physicochemical results and correlating them with the microbiological, it is verified that the MPN.100 mL −1 of the nitrifying organisms were strongly affected by the effluent conditions, being necessary for an effective nitrification process the control of these parameters, mainly pH.

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“…The application of Submerged Aerated Filters (SAFs) for wastewater treatment has been more successful for the removal of recalcitrant organics, suspended particles, phosphorus and nitrification/denitrification than conventional trickling filters (Chen et al 1991;Masuda et al 1991;Watanabe et al 1992). The filter medium in SAFs is as important as in trickling filters to support and retain the growth of the biofilm and maximise organic and nutrient removal.…”

Section: Introductionmentioning

confidence: 99%

Performance linked to residence time distribution by a novel wool-based bioreactor for tertiary sewage treatment

Wheatley

Ishtchenko

et al. 2011

Appl Microbiol Biotechnol

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Laboratory-scale experiments were carried out using up-flow 7 L Submerged Aerated Filter reactors packed with wool fibre or commercial plastic pall rings, Kaldnes, (70% by volume) support media for the tertiary treatment of sewage. The performance of the wool bioreactor was more consistent than that with Kaldnes medium, for both TOC removal (93%) and SS removal (90%). Both plastic and wool-packed bioreactors achieved complete nitrification at the load of about 0.4 kgCOD/m(3)/day. The sludge yield of the wool bioreactor was almost half that of the bioreactor with Kaldnes suggesting that wool could retain residual organics and particulates. The wool however was degraded and it was concluded that wool would have to be considered as additional sacrificial adsorption capacity rather than an alternative medium. The performance was linked to the residence time distribution studies and these changes in the wool structure. Biomass growth increased the retention of the tracer in the wool reactor by, it was suggested, exposing a greater surface area. Results from the plastic media on the other hand showed increased mixing possibly by increasing the mobility of the plastic. Aeration increased the mixing in both reactors, and patterns were in all cases predominantly well-mixed.

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Simultaneous Nitrification and Denitrification in Micro-Aerobic Biofilms

Cited by 56 publications

References 0 publications

Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)

Influence of Strong Diurnal Variations in Sewage Quality on the Performance of Biological Denitrification in Small Community Wastewater Treatment Plants (WWTPs)

Nitrifying, Denitrifying and Heterotrophic Biomass Present in Moving Bed-Reactor

Performance linked to residence time distribution by a novel wool-based bioreactor for tertiary sewage treatment

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