The effect of central air filtration and air conditioning on pollen and microbial contamination

The article describes an experimental study dealing with the possibility of nanotextile materials usage for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP). As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

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Effects of air-conditioning systems in the public areas of hospitals: A scoping review

Epidemiology and Infection ◽

10.1017/s0950268821001990 ◽

2021 ◽

Vol 149 ◽

Author(s):

Han Ting Wu ◽

Qiu Shuang Li ◽

Rong Chen Dai ◽

Shan Liu ◽

Li Wu ◽

...

Keyword(s):

Scoping Review ◽

Air Conditioning ◽

Microbial Contamination ◽

High Efficiency ◽

Cross Sectional ◽

The Public ◽

Public Areas ◽

Almost All ◽

Air Conditioning Systems ◽

The Impact

Abstract Almost all hospitals are equipped with air-conditioning systems to provide a comfortable environment for patients and staff. However, the accumulation of dust and moisture within these systems increases the risk of transmission of microbes and have on occasion been associated with outbreaks of infection. Nevertheless, the impact of air-conditioning on the transmission of microorganisms leading to infection remains largely uncertain. We conducted a scoping review to screen systematically the evidence for such an association in the face of the coronavirus disease 2019 epidemic. PubMed, Embase and Web of Science databases were explored for relevant studies addressing microbial contamination of the air, their transmission and association with infectious diseases. The review process yielded 21 publications, 17 of which were cross-sectional studies, three were cohort studies and one case−control study. Our analysis showed that, compared with naturally ventilated areas, microbial loads were significantly lower in air-conditioned areas, but the incidence of infections increased if not properly managed. The use of high-efficiency particulate air (HEPA) filtration not only decreased transmission of airborne bioaerosols and various microorganisms, but also reduced the risk of infections. By contrast, contaminated air-conditioning systems in hospital rooms were associated with a higher risk of patient infection. Cleaning and maintenance of such systems to recommended standards should be performed regularly and where appropriate, the installation of HEPA filters can effectively mitigate microbial contamination in the public areas of hospitals.

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COVID-19 Spread Faster with Air-Conditioning-Systems

10.32545/encyclopedia202008.0005.v1 ◽

2020 ◽

Author(s):

Maher Al-Baghdadi

Keyword(s):

Virus Infection ◽

Air Conditioning ◽

The Body ◽

Cfd Model ◽

Air Filtration ◽

Public Places ◽

Virus Particles ◽

Viral Particles ◽

Air Conditioning Systems ◽

Air Circulation

Droplets and aerosolized viral particles expelling from the body through coughing or sneezing and it is spreading to nearby surroundings. CFD model has been developed to simulate the air flow and the transport and dispersion of the aerosolized viral particles and fine droplets suspended in the air particles through the office. The study presents two cases involving the spreading limits and pathways of the aerosolized viral particles and fine droplets suspended in the air in a place; without and with air conditioning unit. The results showed that the use of air conditioning systems can increase the chances of spreading COVID-19 virus infection. The air-conditioning unit recirculates the same air inside a room, and this has the potential to create a virus-laden environment. Air circulation indoors such as using air conditioning units should be avoided in closed places. Existing ventilation systems should be expanded to include extraction and air filtration systems and/or germicidal, ultraviolet light. Also, opening a window can help bring in fresh air from the outside and disperse stale air inside, and that could help reduce the possibility of the spread of the virus particles in the closed place. Lastly, crowds of people in closed public places should be avoided.

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Detection and Analysis of Microbial Contamination in Central Air Conditioning System of a University

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.610-613.661 ◽

2012 ◽

Vol 610-613 ◽

pp. 661-664

Author(s):

Hui Xing Li ◽

Bei Ni Li ◽

Geng Geng ◽

Wei Xiao ◽

Wei Wang

Keyword(s):

Air Conditioning ◽

Microbial Contamination ◽

Ventilation System ◽

Inner Product ◽

Public Places ◽

Air Conditioning System ◽

Surface Dust ◽

Photo Catalysis ◽

Air Ventilation ◽

Central Air Conditioning

Objective: Test the wind pipe dust and microorganism pollution status in the central air conditioning system of public buildings in the teaching area.Analysis of microbial pollution of the related factors.Methods:Sampling 6 functionally different area in the teaching building,using the microbiology analysis method on air conditioning system of blower tube surface dust pollution of microorganism detection,and the use of TiO2 photo catalyst purification mechanism on microbial contamination control.Results:on the basis of"centralized air ventilation system in public places sanitary specification",teaching areas of central air conditioning system of dust amount met the requirement basically.Bacterial concentrations generally beyond the standard,fungal concentration accords with the standard.The Method using TiO2 photo catalysis sterilization was proposed. Conclusion:Teaching of regional air conditioning pipe inner product dust weight is relatively large.Microbial pollution is serious.It is necessary that cleaning air conditioning system timely and using TiO2 Photocatalyst purification mechanism for killing air duct surface dust microorganism.

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Preparation of multifunctional AgNPs/PAN nanofiber membrane for air filtration by one-step process

Pigment & Resin Technology ◽

10.1108/prt-08-2019-0075 ◽

2020 ◽

Vol 49 (5) ◽

pp. 355-361

Author(s):

Wenxiu Yang ◽

Lin Li ◽

Shuo Wang ◽

Jinshu Liu

Keyword(s):

Composite Membrane ◽

Air Conditioning ◽

High Performance ◽

Antibacterial Property ◽

Air Filtration ◽

Nanofiber Membrane ◽

Content Type ◽

Composite Nanofiber ◽

One Step ◽

Pan Nanofiber

Purpose The purpose of this paper is to fabricate a high-performance filtration electrospun nanofiber membrane with antibacterial function. The Ag nanoparticles (AgNPs) gotten by reducing AgNO3 act as antimicrobial agent. Then the AgNPs/Polyacrylonitrile (AgNPs/PAN) composite nanofiber membrane was prepared by electrospinning. Design/methodology/approach The electrospun Ag/PAN composite membrane was prepared by one step, in which the Ag particles were acting as antibacterial agent and PAN nanofiber as the upholder of the composite mat. AgNPs were obtained by reducing AgNO3 in N,N-Dimethylformamide (DMF) solution at high temperature. Meanwhile, the PAN particles were added to DMF solution and dissolved. Then the Ag/PAN nanofiber was obtained by electrospinning. Findings The thinner nanofiber can be produced with PAN concentration of 12 per cent and AgNPs concentration of 10 per cent. Finally, the filtration resistance of the composite membrane with antibacterial property is as high as 99.1 per cent, and the filtration efficiency is only 83 Pa. Therefore, the AgNPs/PAN composite membrane is the ideal choice for air filtration with antibacterial property. Originality/value The AgNPs/PAN composite nanofiber membrane has high filtration performance for particulate matter (PM)25 and outstanding antibacterial property to Escherichia coli and Staphylococcus aureus, which can be used with masks, air-conditioning filters (including car air-conditioning filters), window screening and other similar objects.

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