A novel dual-collimation batch reactor for determination of ultraviolet inactivation rate constants for microorganisms in aqueous suspensions

Details

• Personal Author:
  Bahnfleth WP ; Blum DH ; Freihaut JD ; Kremer PA ; Martin SB Jr. ; Shogren ES
• Description:
  We developed, characterized, and tested a new dual-collimation aqueous UV reactor to improve the accuracy and consistency of aqueous k-value determinations. This new system is unique because it collimates UV energy from a single lamp in two opposite directions. The design provides two distinct advantages over traditional single-collimation systems: 1) realtime UV dose (fluence) determination; and 2) simple actinometric determination of the Reactor Factor (RF = 1.06) that relates measured irradiance levels to actual irradiance levels experienced by the microbial suspension. This RF replaces three of the four typical correction factors required for single-collimation reactors. Using this dual-collimation reactor, Bacillus subtilis spores demonstrated inactivation following the classic multi-hit model with k=0.1395 cm 2/mJ. Aspergillus niger spores exhibited two-stage decay with a shoulder, with the resistant fraction of the population (f) of 0.251, k 1=0.1968 cm2/mJ, k2=0.0426 cm2/mJ. [Description provided by NIOSH]
• Subjects:
  Fungi Microbiology Occupational Health Safety Ultraviolet Rays
• Keywords:
  Aqueous-solutions Author Keywords: Collimated-beam Reactor Bacteria Chemical Actinometry Microbial-test-systems Microorganisms Reaction-rates Ultraviolet-light Ultraviolet Germicidal Irradiation
• ISBN:
  9781627480758
• Publisher:
  International Society of Indoor Air Quality and Climate
• Document Type:
  Text
• Genre:
  Proceedings
• Place as Subject:
  OSHA Region 3 ; Pennsylvania ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  DRDS - Division of Respiratory Disease Studies
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  322-327
• Volume:
  1
• NIOSHTIC Number:
  nn:20043177
• Citation:
  Proceedings of the 10th International Conference on Healthy Buildings, July 8-12, 2012, Brisbane, Australia. Santa Cruz, CA: International Society of Indoor Air Quality and Climate, 2012 Jul; 1:322-327
• Email:
  SMartin1@cdc.gov
• Federal Fiscal Year:
  2012
• Peer Reviewed:
  False
• Source Full Name:
  Proceedings of the 10th International Conference on Healthy Buildings, July 8-12, 2012, Brisbane, Australia
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:fe5cd4ad3e1c214b2992a61b19210660240ee1ec3f682558412ca2a0aa90ef39fb40b5eee2ca794c1532dde4c5d0dd4ca193f4990f8f06d8b6e8bf00ea9105d3
• Download URL:
  https://stacks.cdc.gov/view/cdc/195165/cdc_195165_DS1.pdf
• File Type:
  [PDF - 282.65 KB ]