The present paper evaluates the technical and economical feasibility of converting wet chemical scrubbers to biotrickling filters for H2S control at the Orange County Sanitation District (OCSD), California. Results of 8 months of continuous operation of a biotrickling filter treating 16,000 m3h-1of foul air are analyzed. The reactor was operated at a gas contact time of 1.6 to 2.2 seconds reaching H2S elimination capacities up to 105-110 g H2S m-3h-1, consistently maintaining outlet concentrations well below the regulatory limits (24 h average of 1 ppmv) and demonstrating to be very robust against temporary changes. Also, a cost-benefit analysis of the conversion was performed. Savings from chemicals, energy and water usage compared to a chemical scrubber operated in parallel to the biotrickling filter throughout the project indicated that the payback time of the conversion was about 1.3 years. Cost savings ranged between US$ 40,000 per year, per scrubber. While the above number may be specific to OCSD conditions, the cost analysis suggests that there is a significant benefit of converting chemical scrubbers to biotrickling filters over a wide range of operating conditions. © IWA Publishing 2004.
|Journal||Water Science and Technology|
|Publication status||Published - 4 Oct 2004|
- Biotrickling filter
- Chemical scrubber conversion
- Cost-benefit analysis
- Hydrogen sulfide
- Operating costs