RESUMO
Biological activated carbon (BAC) is one of the important treatment processes in wastewater and advanced water treatment. However, the BAC process has been reported to have antimicrobial resistance (AMR) risks. In this study, a new BAC-related treatment process was developed to reduce AMR caused by BAC treatment: ozone/peroxymonosulfate-BAC (O3/PMS-BAC). The O3/PMS-BAC showed better treatment performance on the targeted five antibiotics and dissolved organic matter removal than O3-BAC and BAC treatments. The O3/PMS-BAC process had better control over the AMR than the O3-BAC and BAC processes. Specifically, the amount of targeted antibiotic-resistant bacteria in the effluent and biofilm of O3/PMS-BAC was only 0.01-0.03 and 0.11-0.26 times that of the BAC process, respectively. Additionally, the O3/PMS-BAC process removed 1.76 %-62.83 % and 38.14 %-99.27 % more of the targeted ARGs in the effluent and biofilm than the BAC process. The total relative abundance of the targeted 12 ARGs in the O3/PMS-BAC effluent was decreased by 86 % compared to the effluent after BAC treatment. In addition, Proteobacteria and Bacteroidetes were probably the main hosts for transmitting ARGs in this study, and their relative abundance decreased by 9.6 % and 6.0 % in the effluent of the O3/PMS-BAC treatment compared to that in BAC treatment. The relationship analysis revealed that controlling antibiotic discharge was crucial for managing AMR, as antibiotics were closely related to both ARGs and bacteria associated with their emergence. The results showed that the newly developed treatment process could reduce AMR caused by BAC treatment while ensuring effluent quality. Therefore, O3/PMS-BAC is a promising alternative to BAC treatment for future applications.
RESUMO
Bird strike accidents mainly occur in the airport area. Reducing bird activities through bird repeller equipment is one of the main measures to prevent bird strike. In this study, two bird species with high-risk, pigeon (Columba livia domestica) and kestrel (Falco tinnunculus), were selected as the subjects and the gas gun and directional acoustic bird repeller were selected as the evaluation objects in Shenyang Taoxian International Airport. This study aimed to examine the behavioral responses of birds at different distances during the normal operation of these equipment to explore their effective distance and effects. The results showed that the vigilant and escape behaviors of pigeons and kestrels at 10 m and 30 m away from the gas gun bird repeller which were significantly higher than those of the control, while the number of these behaviors at 50 m away was not significantly different from that of the control. Pigeons and kestrels at 50 m and 100 m away from the directional acoustic bird repeller could significantly increase their vigilant and escape behaviors, whereas the repeller could significantly cause kestrels to increase their vigilant behavior at 300 m away. We concluded that the effective bird expel distance of the gas gun was 30 m, and the directional acoustic bird repeller could effectively expel to 300 m, and that the effect of the directional acoustic bird repeller on birds was stronger than the gas gun. Our results could provide a reference for the introduction and rational use of bird expel equipment in the airports.
