Pathogen Reduction
Pathogen Reduction in Fixed Film Filters
Dr Barbara Grimes
NCDENR OSWW
1642 Mail Service Center
Raleigh NC 27699-1642
Fixed film filters for wastewater treatment are also called biofilm filters. These filters
provide a support structure for free-living organisms to attach and biofilm to grow.
Wastewater treatment depends upon the microbiological and macrobiological growth.
Some of the support materials for biological growth include gravel, plastic, sand,
activated carbon, and natural and synthetic fibers. Two types of systems will be
discussed, those that remain fixed where wastewater flows over the media (trickles)
and those that have a moving medium (rotating biological contactors). Also,
wastewater treatment may include dual processes, including fixed and suspended
media components. These biofilms - which are active ecosystems - are formed from
bacteria, algae, fungi, protozoa, rotifers, annelid worms, nematodes, and insect
larvae. The reduction and potential reduction of wastewater human pathogens as
wastewater passes through the filters will be presented. Pathogen groups that will be
covered, are viruses, bacteria, protozoan, and worms. Also, a discussion of pathogen
indicators, such as fecal coliforms and bacteriophages will be presented. These
indicators will be presented as to how these may or may not adequately represent the
fate and transport of potential wastewater pathogens through the fixed film filters.
Please address any questions to Dr. David Lindbo.
This page created by
Roland O.
Coburn,
Research Technician I
on 2/17/03.