Site-related and seasonal variation of bioaerosol emission in an indoor wastewater treatment station: level, characteristics of particle size, and microbial structure

Abstract

The emission of the airborne bacteria and fungi from an indoor wastewater treatment station adopting an integrated oxidation ditch with a vertical circle was investigated. Microbial samples were collected by the six-stage viable Andersen cascade impactor, and the samples were collected in triplicate in each sampling site per season. Culture-based method was applied to determine the concentrations of the airborne bacteria and fungi, while the cloning/ sequencing method was used to characterize the genetic structure and community diversity of airborne bacteria. The highest concentrations of airborne bacteria (4155 ± 550 CFU/m 3 ) and fungi (883 ± 150 CFU/m 3 ) were obtained in June (summer). The lowest concentration of bacteria (1458 ± 434 CFU/m 3 ) was determined in January (winter), and the lowest concentration of fungi (169 ± 40 CFU/m 3 ) was found in March (spring), respectively. The particle size distribution analysis showed that most culturable bacteria obtained in all the sampling sites were in the particle size range of 1.1-4.7 lm. Most culturable fungi had particle sizes in the range 1.1-3.3 lm. Microbial population analysis showed that Bacillus sp., Acinetobacter sp., and Lysinibacillus were the main groups obtained in S1.Enterobacter was the dominant group in sampling site S2. Both the concentrations and particle size distribution of the bioaerosols in the enclosed space presented a seasonal and site-related variation. Concentration and richness of microorganisms in bioaerosols in June were higher than in September and January. The particle size distribution varied between the sampling sites, and proportion of large particles was higher in S2 than in S1 because of the settlement of large particles. Pathogenic species, such as Acinetobacter lwoffii, Staphylococcus saprophyticus, and Enterobacter sp., were isolated from the bioaerosols, which could pose serious latent danger to sewage workers' health.

Assessment of Microbial Air Quality within Facilities of Waste Transfer Stations and Disposal Sites of Lahore, Pakistan

“…In contrast to bacteria, the highest fungal concentration was recorded in the dry season than wet season and this corresponds to the results of other researchers [9,39]. In previous studies, the highest concentration of bioaerosol was found in the air samples of wastewater treatment facilities during summer and autumn seasons than that of spring and winter seasons because of small rainfall and suitable temperature [40,41].…”

Quantifying Airborne Dispersal Route of Corynespora cassiicola in Greenhouses

“…Most previous studies on particle size distribution have focused on microbes derived from buildings, oceans and open biomass burning ( Deacon et al, 2009 ; Lazaridis et al, 2015 ; Katsivela et al, 2017 ; Li et al, 2017 ; Wei et al, 2019 ); however, scarce information is available about the aerospore size distribution of plant fungal pathogens. In our research, the particle size of C. cassiicola released by cucumber plants ranged predominately from 2.1 to 4.7 μm (accounting for 71.97%), which was different from the particle size of most culturable mold fungi distributed in the 1.1–3.3 μm size range ( Deacon et al, 2009 ; Ding et al, 2016 ), possibly because the average dimension of C. cassiicola (82.34 μm × 7.11 μm) is much larger than the average dimension of most mold fungi (3.78 μm × 3.50 μm) (unpublished data). The current lack of information on the particle size distribution of pathogens emitted from crop plants limits further study to model dispersion ( Taha et al, 2007 ).…”

Identification of airborne fungi’s concentrations in indoor and outdoor air of municipal wastewater treatment plant

“…Several studies have suggested that the structure, size, concentration, and microbial population of bioaerosols is affected by the source of production, the mechanism of air diffusion, and in general, the weather conditions, such as temperature, humidity, wind speed, and UV index (12)(13)(14). (41). In this study, the results demonstrated that among the selected units, the highest concentrations of fungi were observed in the grit chamber unit.…”