Escape and functional alterations of microbial aerosol particles containing Pseudomonas sp. during wastewater treatment

Wastewater treatment plants (WWTP) are considered sources of bioaerosols emission that negatively affects the surrounding atmosphere. This study focused on Pseudomonas sp. Emissions in bioaerosols from a WWTP that adopts the A2O treatment process, and their inactivation through ultraviolet (UV) radiation. High-throughput sequencing was used to assay the microbial population, and functional composition profiles were predicted using 16 S rRNA sequencing data with PICRUSt2. Recorded emission levels of airborne bacteria and Pseudomonas sp. In WWTP were 130 ± 83-6113 ± 3015 CFU/m3 and 0-6431 ± 1945 CFU/m3, respectively. Bioaerosol emissions presented site-related and temporal variation. Over 80% of Pseudomonas sp. Were attached to coarse particles with sizes over 2.1 μm. Bioaerosol concentration and particle-size distribution in the air were closely related to ambient temperature, relative humidity, light intensity, and wind speed. Exposure to 45.67 μW/cm3 UV radiation led to a significant decline in bioaerosol concentrations in the air, and reduction rate reached 89.16% and 95.77% for airborne bacteria and Pseudomonas sp., respectively. The results suggested that UV radiation can be an effective method in reducing bioaerosols. Compared with other bacteria, Pseudomonas stutzeri and Bacillus sp. Are more resistant to UV radiation. The abundance of antibiotic resistance genes noticeably receded when exposed to UV irradiation. The relative abundance of cationic antimicrobial peptide resistance, categorized under human diseases in KEGG (level 3), significantly decreased in Pseudomonas sp. After 120 min of UV irradiation. This study provides a novel insight into the control of bioaerosol emissions carrying pathogenic bacteria.