-
Laboratoire des Mate ´riaux, Surfaces et Proce ´de ´s pour la
- 上一篇：聚氯乙烯管件注射模设计英文文献和中文翻译
- 下一篇：热电偶英文文献和中文翻译
Catalyse (LMSPC), CNRS, Strasbourg University, 25 rue
Becquerel, 67087 Strasbourg, France, and Laboratoire
Ge ´ne ´tique Mole ´culaire, Ge ´nomique, Microbiologie
(GMGM), CNRS, Strasbourg University, 28 rue Goethe,
67028 Strasbourg, France 10182
Received October 9, 2009. Revised manuscript received
February 19, 2010. Accepted February 19, 2010.
Comparing the UV-A photocatalytic treatment of bioaerosols
contaminated with different airborne microorganisms such as
L. pneumophila bacteria, T2 bacteriophage viruses and B.
atrophaeus bacterial spores, pointed out a decontamination
sensitivity following the bacteria virus bacterial spore ranking
order, differing from that obtained for liquid-phase or surface
UV-Aphotocatalytic disinfection. First-principles CFDinvestigation
applied to a model annular photoreactor evidenced that
larger the microorganism size, higher the hit probability with
the photocatalytic surfaces.Applied to a commercial photocatalytic
purifier case-study, the CFD calculations showed that the
performances of the studied purifier could strongly benefit from
rational reactor design engineering. The results obtained
highlighted the required necessity to specifically investigate
the removal of airborne microorganisms in terms of reactor
design, and not to simply transpose the results obtained from
studies performed toward chemical pollutants, especially for
a successful commercial implementation of air decontamination
photoreactors. This illustrated the importance of the aerody-
namics in air decontamination, directly resulting from the
microorganism morphology.
Introduction
The regulation of volatile organic compounds (VOC) has
recently created a strong incentive for innovative sustainable
environmental research. As a result, the indoor air quality
control is receiving a growing interest due to the public
concern over human health. Targets are not only VOC or
more generally chemical pollutants, usually malodorous,
toxic, or contributing to global warming, but include also
airbornemicroorganisms such as bacteria, viruses, or spores.
TheU.S. Environmental Protection Agency considers the
indoor air pollution as one of the top five environmental
risks to public health, since we spend 70 90% of our time
indoors,where pollutant contents are higher (1, 2). Biological
pollutants are particularly threatening because of the con-
tinuously increasing resistance of microorganisms against
medical treatments and their dissemination due to the
intensificationof humantransports, as shownwithworldwide
damages (SARS, avian, or porcine flu). If many airborne
microorganisms (AMO) show no or a low virulence, an
impressive variety of AMO are a real hazard to safety, such
as bacteria, viruses, fungi, with a huge societal impact in
terms of mortality and cost (3).
The removal of airborne chemical or biological pollutants
is therefore a challenging task for which photocatalysis has
attracted attention since decades for acting as an efficient
air treatment technology because of the oxidizing power of
UVA-irradiated semiconductors (4). The analogy between
chemical and biological targets results from the organic
nature of themicroorganismconstituents that photocatalysis
can oxidize through oxidizing photoholes or •OH radicals,
similarly to liquid and gas phase organics. The cell walls
being a complex assembly of highmolecular weight organic
compounds (MW> 10 000), contactwithTiO2 causes oxidative
damage to cell membrane, considered as the first barrier
maintaining the vital cell functions and the first target for