Behaviour and control of nutrients in the enhanced aerobic digestion process: Pilot‐scale studies

Anderson, Bruce; Mavinic, Donald S.

doi:10.1080/09593339309385295

Cited by 11 publications

(6 citation statements)

References 9 publications

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“…The loading of nitrogen in the liquid (dissolved) phase increased from 4 kg/day entering the digesters to 20 kg/ day exiting the digesters. This is generally consistent with previous observations of nitrogen release during aerobic digestion (e.g., Anderson & Mavinic, 1993;Bishop & Farmer, 1978;Kim et al, 2002;Matsuda et al, 1988).…”

Section: Research Articlesupporting

confidence: 93%

“…Are the concentrations and fluxes of inorganic nitrogen in the sidestream high enough to interfere with EBPR in the mainstream treatment process? Bishop and Farmer (1978), Matsuda, Ide, and Fujii (1988), Tonkovic (1999), Anderson and Mavinic (1993), Kim et al (2002), and Ju et al (2005) have partially addressed these questions in bench-or pilot-scale systems, but to the best of our knowledge, there has not yet been an investigation of nutrient mass fluxes at a full-scale facility employing aerobic digestion. Therefore, toward answering the questions posed above, the overall objective of this paper is to quantitatively assess the fate of nitrogen and phosphorus at treatment facilities that employ biological nutrient removal (BNR), aerobic digestion, and sidestream recycle.…”

Section: Research Articlementioning

confidence: 99%

“…Are the concentrations and fluxes of inorganic nitrogen in the sidestream high enough to interfere with EBPR in the mainstream treatment process? Bishop and Farmer (), Matsuda, Ide, and Fujii (), Tonkovic (), Anderson and Mavinic (), Kim et al (), and Ju et al () have partially addressed these questions in bench‐ or pilot‐scale systems, but to the best of our knowledge, there has not yet been an investigation of nutrient mass fluxes at a full‐scale facility employing aerobic digestion.…”

Section: Introductionmentioning

confidence: 99%

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Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle

Kassouf

Parra

Mulford

et al. 2019

Water Environment Research

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At water reclamation facilities, recycling of nutrients (nitrogen and phosphorus) from solids‐handling processes to the mainstream treatment process can have detrimental effects on biological nutrient removal systems. In this study, mass fluxes of nitrogen and phosphorus were quantified through the treatment trains at the Northwest Regional Water Reclamation Facility (NWRWRF) and the adjoining Biosolids Management Facility (BMF), which receives sludge from several water reclamation facilities in Hillsborough County, Florida. The driving objectives were to determine (a) whether the return stream from BMF to NWRWRF (i.e., the “sidestream”) represents a significant source of nitrogen and phosphorus to NWRWRF, and (b) whether the sidestream return from BMF is interfering with biological nutrient removal processes at NWRWRF. We determined that nearly half of the overall phosphorus flux into NWRWRF is recycled from the BMF sidestream. This leads to an increased cost of treatment, for example, for alum used in phosphorus removal at NWRWRF. In contrast to phosphorus, the flux of nitrogen from BMF to NWRWRF is small (~3%) compared with the flux of nitrogen entering NWRWRF in raw wastewater. However, nitrogen in the sidestream is mostly in the form of nitrate, which prevents anaerobic conditions from developing in the fermentation basin at NWRWRF, and thereby interferes with the enhanced biological phosphorus removal (EBPR) process. Some measurements suggest that fermentation and release of phosphorus may occur in the return activated sludge line (despite the relatively short residence time in that line), which supports EBPR and may partially compensate for anoxic (denitrifying) conditions in the fermentation basin. Therefore, overall, NWRWRF is able to meet its permit limits for phosphorus through a combination of EBPR and alum addition. Although the fluxes measured here are particular to the treatment systems under consideration, the general trends observed are likely to apply to many similar facilities that employ biological nutrient removal, aerobic digestion, and sidestream recycle, particularly those with regional biosolids management facilities. We recommend that such facilities consider (a) removal or recovery of phosphorus from their sidestreams and (b) returning sidestreams downstream of fermentation basins to avoid inhibition of EBPR processes. Practitioner points Sidestreams from aerobic digestion can represent significant sources of phosphorus to mainstream wastewater treatment. Recycle of nitrate in aerobic digestion sidestreams can interfere with enhanced biological phosphorus removal (EBPR) during mainstream treatment. Fermentation of return activated sludge (RAS) can support EBPR, even under short average hydraulic residence times (minutes).

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Section: Research Articlesupporting

confidence: 93%

Section: Research Articlementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle

Kassouf

Parra

Mulford

et al. 2019

Water Environment Research

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“…It is apparent that the degradation efficiencies of SS and VSS in the thermophilic simultaneous metal leaching and aerobic digestion process were higher than those in the traditional thermophilic aerobic digestion (control test). It has been reported that the activities of heterotrophic microorganisms were inhibited when the pH was below 5.6, and thereafter the rate of VSS degradation was slowed down in the aerobic sludge digestion [31]. However, it was observed that the sludge digestion still proceeded when the pH dropped below 5.6 in this study.…”

Section: Degradation Of Solids In Sludgementioning

confidence: 50%

Simultaneous metal leaching and sludge digestion by thermophilic microorganisms: Effect of solids content

Chen

Pan

2010

Journal of Hazardous Materials

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“…Instead, both pH and fluorescence profiles reflected the different stages of the digestion process. The presence of nitrifiers in aerobic sludge digestion processes is well‐known (e.g., refs 16, 17). Plausibly, the initial pH increase resulted from the ammonium release associated with the heterotrophic endogenous degradation of intracellular proteins.…”

Section: Resultsmentioning

confidence: 99%

On-line Fluorescence Profile of Aerobic Sludge Digestion

1999

Biotechnol. Prog.

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An online fluorometer designed for following intracellular NAD(P)H was used to monitor aerobic sludge digestion experiments. The fluorescence showed an initial rise to a high plateau, a sharp decline after staying at the plateau for 20-60 h, and a trailing very slow decrease. The characteristic fluorescence profile was shown to result mainly from the solids-associated fluorescence, after ruling out other factors such as pH, temperature, and supernatant fluorescence. The fluorescence profile was, however, not a mere result of the decreasing solids concentration. The varying sludge viability and population composition (e.g., the decay of heterotrophs and the increasing fraction of nitrifiers) played important roles. The fluorescence profile correlated well with the profile of the viable heterotrophic cell number concentration evaluated with TSB-agar plates. The initial increase of the number concentration was attributed to the growth of multiple small bacteria from the lysate of each large microorganism, which was demonstrated in the experiments with baker's yeast as the starting culture for digestion. The fluorescence profiles observed in the yeast experiments were similar to those in the sludge experiments. Responding to glucose additions and the switch from aerobic to anaerobic conditions, the yeast systems showed typical step increases of fluorescence as expected from the change of NAD(P)H level associated with heterotrophic metabolism. However, no such fluorescence responses were detectable in the sludge digestion systems. NAD(P)H were thus uncertain to be responsible for the online fluorescence observed. Nonetheless, the initial fluorescence plateau corresponded to the period of rapid digestion and, for the plant studied, the EPA regulation criteria of VSS reduction >38% and/or SOUR <1.5 mg of O(2) (g of TS)(-)(1) h(-)(1) were satisfied at the end of the plateau. The online fluorescence provides an effective means of monitoring the aerobic sludge digestion process.

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Behaviour and control of nutrients in the enhanced aerobic digestion process: Pilot‐scale studies

Cited by 11 publications

References 9 publications

Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle

Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle

Simultaneous metal leaching and sludge digestion by thermophilic microorganisms: Effect of solids content

On-line Fluorescence Profile of Aerobic Sludge Digestion

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