Biofiltration for the Treatment of
Recalcitrant VOCs in Polluted Air
Streams
Sarah Mahon, PE
Mane6960H01
Air & Water Pollution Control Engineering
Fall 2013
The Problem
http://www.bioremediation-specialists.com/Reductive-Processes.php
Solution: Soil Vapor Extraction
http://commons.wikimedia.org/wiki/File:Conceptual_Diagram_of_Basic_Soil_Vapor_Extraction_(SVE)_System_for_Vadose_Zone_Remediation.png
Air Treatment Options for Destruction
of VOCs
• Thermal oxidation (expensive, creates dioxins,
constant fuel to maintain 1300-1500F)
• Catalytic oxidation (expensive, rare earth
metals, constant fuel to maintain 600-800F)
• Activated carbon (expensive, frequent
replacement of spent carbon)
• Biofilters (inexpensive, but can not treat all
VOCs)
Biofiltration
• Dehalogenation (directly consume target
contaminants)
• Dehalorespiration (use of halogenated
compounds as electron acceptors in anaerobic
respiration)
• Cometabolism (microbes breakdown
compound while using another as a primary
substrate)
http://www.washoecounty.us/water/PCE_background.htm
Biofiltration
• Bioaugmentation (insert multiple strains of
bacteria that breakdown specific compounds)
• UV Photodegredation (pretreatment –
breakdown compounds into components
easier for biofilter to digest)
Conclusions
• Need bacterial strains capable of breaking down
toxic compounds
• Some degradation products more toxic than
parent compounds, which can kill bacterial
strains
• Some benchscale studies have shown success
with cometabolism and UV pretreatment (few
full-scale studies due to concerns)
• More research needed for certain types of
recalcitrant VOCs