Evaluation of the Bioaerosol Inactivation Ability of Chitosan-Coated Antimicrobial Filters

Abstract

This work considers the enhancement of indoor bioaerosol removal efficiency by liquid coating of the antimicrobial agent chitosan onto polypropylene fibrous filters (CCFs). Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) were chosen as the tested bioaerosols. The results revealed that 2.5% (w/w) of CCFs have significantly higher bioaerosol survival capability (23% and 34% of E. coli and B. subtilis, respectively), compared to an untreated filter (65% and 64% for E. coli and B. subtilis, respectively). Increasing face velocity and relative humidity during operating CCFs could reduce the bioaerosol removal capability. The regression analysis of the experimental findings demonstrated that the higher coating concentration of chitosan had the most positive influence on bioaerosol removal, while the face velocity and relative humidity had a negative influence, but a milder effect was observed (R2 = 0.83 and 0.81 for E. coli and B. subtilis bioaerosols, respectively). A CCF-loaded air-cleaning device was tested in a real indoor environment and resulted in 80.1% bioaerosol removal within 3 h of operating, which suggests that the chitosan-coated filter has the potential for further application in improving indoor air quality in the future.

Fabrication of air filters with advanced filtration performance for removal of viral aerosols and control the spread of COVID-19

“… Ref Results Microorganism or pollutant Materials [ 63 ] (Particulate matter 2.5 > 98.0%, particulate matter10 > 98.4%), high flow rate (1.9 m s −-1 after 1 h) a low (21 Pa) pressure drop. Particulate matter Chitosan/ poly(methylmethacrylate)/polydimethylsiloxane [ 64 ] 99.3% filtration efficacy for NaCl, and 99.4% for DEHS aerosol (Diisooctyl sebacate) Diisooctyl sebacate aerosol N-halamine/ poly(vinyl alcohol)/ chitosan [ 65 ] In 3 h of operating, 80.1% bioaerosol was removed B. subtilis and E. coli Chitosan/ polypropylene [ 66 ] After 120 min, the survival rate of microorganisms on pristine nylon, nylon/chitosan, as well as chitosan dipped nylon-6 nano-fibrous filters decreased to 8.4%, 7.1%, and 2.8%. E. coli and B. subtilis Nylon/chitosan [ 68 ] 99.69% efficiency for particulate matter 2.5 and 99.89% removal efficiency for particulate matter 10 Particulate matters Cholinium alginate [ 69 ] 94.92 and 96.94% inactivation Bacteriophage phi 6 and SARS-CoV-2 Delta variant Calcium alginate films [ 70 ] 99.99% effectiveness toward coronavirus, with low cytotoxicity Coronavirus Alginate/copper sulfate [ 71 ] 95% efficiency to capture aerosols Aerosols Gelatin/β–cyclodextrin [ 72 ] Capture effectiveness of modified HEPA filter was up to 2730 pfu/mm 2 within 10 min.…”

“…Hsu et al evaluated the inactivation ability of bioaerosols by chitosan-coated antimicrobial filters [ 65 ]. In this study, chitosan as an antimicrobial agent has coated on polypropylene fibrous filters through the liquid coating process, and the development of removal efficacy of indoor bioaerosols (tested bioaerosols: B. subtilis and E. coli ) was considered.…”

Simultaneous Capture and Inactivation of Airborne Bacteria by a Dual-Zone Electrostatically Actuated Filter

“…The simultaneous removal and inactivation technologies for bioaerosols in ventilation systems need further study. Some researchers tried to solve the problem by coating or growing antimicrobial components onto filter fibers. , Xiao et al incorporated silver nanoparticles into poly­(vinylidene difluoride) nanofiber membranes. The study demonstrated that the modified membranes could resist Staphylococcus aureus and Escherichia coli with a bacterial reduction rate of 99.6% and capture efficiency of 99.95% with a pressure drop of 137.5 Pa at 85 L/min .…”

Evaluation of the Inactivating Ability of Carbon-Nanotube Coated Plasma Treatment on Bioaerosols for Indoor Air Cleaning

“…However, this liquiddisinfectant intervening technique is not suitable for peroneal-occupied space because of a potential visual-annoying problem. Hsu et al [16] used the chitosan-coated antimicrobial filter to inactivate E. coli and Bacillus subtilis bioaerosols in the environmental-controlled chamber. The results revealed that 2.5% (w/w) of chitosan-coated antimicrobial filters have significantly more additional bioaerosol inactivating ability than conventional non-chemical coated air filters.…”