Costs of Biofilter Operation Compared to Alternatives

Technology Cost per million cubic feet air Technology Operating costs
Fuel/chemical consumption Power
Incineration $ 130 Incinerator $ 15 per cfm Negligible
Chlorine $ 60 Wet chemical scrubber up to $ 8 per cfm 1 W per cfm
Ozone $ 60 Biofilter 0 0.6 W per cfm
Activated carbon with regeneration $ 20
Biofiltration $ 8
Source: Bohn (1992)

Although the actual costs vary with each case, biofiltration is always the more cost effective technology.

Biofilter Operating Costs

  • Electricity: Generally, electricity to operate the Fan/Blower(s) is the largest portion of the operating cost for a biofilter system.
  • Media replacement: The second largest operating cost is generally media replacement. Depending on various factors, media replacement will typically occur after at least 4 years of operation. The cost for media replacement consists of removing the old media, obtaining new media and placing the new media.
  • Periodic inspection and testing: Labor and laboratory costs associated with monitoring and checking the biofilter system are typically minimal.
  • Equipment maintenance: There are few mechanical parts associated with a biofilter system. As a result, maintenance costs are typically minimal.
  • By-product treatment: The only by-product requiring further treatment is waste water from the biofilter drain system. This amount is normally small and results in minimal cost. Very high ammonia or very high reduced sulphur compounds (RSC) in the air stream can lead to higher disposal cost for the wastewater. There is low disposal cost for the media as it does not require further treatment prior to uses such as landscaping.

Indicative costs, energy consumption and materials balance of some air treatment techniques

Technique Raw materials Waste materials and emissions Energy requirements (kWh/m3) Costs (Dft/1000 m3)
Biofiltration Filter material, water Decompose filter materials, CO2, water and organic degradation products ≤ 1 0.50 5.0
Bio-scrubbing Water Biomass, CO2, water and organic degradation products 1.6 3.0 3.0 6.0
Scrubbing (Chemical) Water or solvent + chemicals Polluted water or solvent, concentrated contaminants, polluted regeneration solvent 0.1 1.0
5 10 (for regeneration)
1.0 20.0
Adsorption (by activated carbon) Activated carbon (regeneration solvent) Active carbon with contaminants, polluted regeneration solvent 100200 kWh/ton VOC 2 - 4 ton of steam/ton VOC for regeneration 1.0 10.0
Incineration Fuel Exhaust gases 1-3 +0-2×106 kJ/1000 m3 2.50 25.0
Catalytic incineration Catalyst fuel Exhaust gases and split/ poisoned catalyst 1-2 +0-106 kJ/1000 m3 2.50 20.0
Source: Biotechnology for a Clean Environment, Prevention, Detection, Remediation
Note: Indicative costs for Dutch situation