Changes in Bacterial Aerosols with Height above Aeration Tanks

Sawyer, Bernard; Rao, Krishna C.; O'Brien, Parnell; Elenbogen, G; Zenz, David R.; Lue‐Hing, Cecil

doi:10.1061/(asce)0733-9372(1996)122:5(368)

Cited by 18 publications

(15 citation statements)

References 10 publications

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“…The transfer of microorganisms from raw water to the atmosphere occurs mainly during aeration and mechanical agitation, with average bacterial concentrations as high as 2,100 CFU/m 3 and fungal concentrations of up to 45 CFU/m 3 found in aerosol emitted by aeration tanks in activated sludge plants (Sánchez-Monedero et al 2008).Variation of culturable bacteria concentrations in the surrounding air at different heights and distances from aeration tanks has been reported by Brenner et al (1988) and Sawyer et al (1996). These studies were based on culture-dependent methods, however, which do not necessarily reflect the bioaerosol diversity and their genetic structure.…”

Section: Introductionmentioning

confidence: 94%

Assessing genetic structure, diversity of bacterial aerosol from aeration system in an oxidation ditch wastewater treatment plant by culture methods and bio-molecular tools

Han

Liu

2012

Environ Monit Assess

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Airborne bacteria emissions from oxidation ditch with rotating aeration brushes were investigated in a municipal wastewater treatment plant in Beijing, China. Microbial samples were collected at different distances from the rotating brushes, different heights above the water surface, and different operation state over a 3-month period (April, May, and June) in order to estimate the seasonal variation and site-related distribution characteristics of the microorganisms present. The concentration of bacterial aerosol was analyzed by culture methods, while their dominant species, genetic structure and diversity were assayed using bio-molecular tools. Results showed that total microbial concentrations were highest in June and lowest in April. The mechanical rotation caused remarkable variation in concentration and diversity of culturable airborne bacteria before and after the rotating brushes. The highest concentration was observed near the rotating brushes (931±129-3,952±730 CFU/m 3 ), with concentration decreasing as distance and height increased. Bacterial community polymerase chain reaction and denaturing gradient gel electrophoresis indicated that diversity decreased gradually with increasing height above the water surface but remained relatively constant at the same height. All dominant bacteria identified by DNA sequence analysis belonged to Firmicutes. Pathogenic species such as Moraxella nonliquefaciens and Flavobacterium odoratum were isolated from the bioaerosols. Due to the serious health risks involved, exposure of sewage workers to airborne microorganisms caused by brush aerators should be monitored and controlled.

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Section: Introductionmentioning

confidence: 94%

Assessing genetic structure, diversity of bacterial aerosol from aeration system in an oxidation ditch wastewater treatment plant by culture methods and bio-molecular tools

Han

Liu

2012

Environ Monit Assess

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“…Some bacteria are of health concern since they may cause diseases such as asthma (due to allergens) or other respiratory illnesses (Macher, Ammann, Milton, Burge, & Morey, 1999). Previous studies have found that composting facilities and wastewater treatment facilities are large bioaerosol sources and may therefore represent an exposure hazard to workers and people living in the vicinity of these locations (Johnson, Camann, Harding, & Sober, 1979;Sawyer et al, 1996). Hryhorczuk et al (2001) showed a statistically significant pattern of decreasing bioaerosol concentration with distance from a composting pile, a known source of bioaerosols.…”

Section: Introductionmentioning

confidence: 99%

A static water surface sampler to measure bioaerosol deposition and characterize microbial community diversity

Sahu

Grimberg

Holsen

2005

Journal of Aerosol Science

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“…At the higher sparging rates, particles of 15 and 19 m could have been kept aloft, respectively. At the lowest sparging rate at all three of the sampling heights, the measured PM 10 and TSP concentrations were within 10% of each other. For the other two sparging rates, there was a significant difference between the PM 10 and TSP size fractions (Table 2).…”

Section: Rozen Formulationmentioning

confidence: 68%

“…A total suspended particulate (TSP), coarse particulate matter (PM 10 ) and fine particulate matter (PM 2.5 ) sample was collected at each sampling height using MiniVol aerosol samplers (Air Metrics). PM 10 and PM 2.5 refer to airborne particles with an aerodynamic diameter Ͻ10 and 2.5 m, respectively.…”

Section: Aerosol Samplingmentioning

confidence: 99%

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Aerosol Entrainment from a Sparged Non-Newtonian Slurry

Fritz

2006

Journal of the Air & Waste Management Association

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Previous bench-scale experiments have provided data necessary for the development of empirical models that describe aerosol entrainment from bubble bursting. However, previous work has not been extended to non-Newtonian liquid slurries. Design of a waste treatment plant on the Hanford Site in Washington required an evaluation of the applicability of these models outside of their intended range. For this evaluation, aerosol measurements were conducted above an air-sparged mixing tank filled with simulated waste slurry possessing Bingham plastic rheological properties. Three aerosol-size fractions were measured at three sampling heights and for three different sparging rates. The measured entrainment was compared with entrainment models. One model developed based on bench-scale air-water experiments agreed well with measured entrainment. Another model did not agree well with the measured entrainment. It appeared that the source of discrepancy between measured and modeled entrainment stemmed from application beyond the range of data used to develop the model. A possible separation in entrainment coefficients between air-water and steam-water systems was identified. A third entrainment model was adapted to match experimental conditions and fit a posteri to the experimental data, resulting in a modified version that resulted in estimated entrainment rates similar to the first model.

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Changes in Bacterial Aerosols with Height above Aeration Tanks

Cited by 18 publications

References 10 publications

Assessing genetic structure, diversity of bacterial aerosol from aeration system in an oxidation ditch wastewater treatment plant by culture methods and bio-molecular tools

Assessing genetic structure, diversity of bacterial aerosol from aeration system in an oxidation ditch wastewater treatment plant by culture methods and bio-molecular tools

A static water surface sampler to measure bioaerosol deposition and characterize microbial community diversity

Aerosol Entrainment from a Sparged Non-Newtonian Slurry

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