A lava rock-based biofilter for the treatment of alpha-pinene

Biofiltration is an emerging technology in the United States that utilizes microorganisms to biodegrade harmful contaminants in air to carbon dioxide and water. Biofiltration is not only more cost effective, but also more environmentally friendly than traditional technologies such as thermal oxidation and chemical scrubbing. The primary objectives of the study were to operate a lava rock-based laboratory biofiltration system for the removal of alpha-pinene. A consortium of microorganisms to be used as an inoculum was recovered that was able to use alpha-pinene as a sole source of carbon and energy. The removal of alpha-pinene from the laboratory system was monitored with a total hydrocarbon analyzer (THA). Based on THA analysis, elimination capacities as high as 100+ g/m(3)/h were obtained in the laboratory biofilters. Removal efficiencies averaged 99% over a two year period. The solid support maintained a neutral pH with no buffer addition throughout the two year study and microbial levels were maintained between 10(6) and 10(7) colony forming units (CFU)/g of solid support. Bacillus and Rhodococcus species were found to be the majority of the microorganisms in the biofilters over a two year period. This is the first time an organism from either of these genera has been reported to utilize alpha-pinene as a sole source of carbon and energy. Overall, a preselected consortium of microorganisms coupled with lava rock as a biofilter solid support achieved extended alphapinene treatment levels that far exceed previously published values. (c) 2005 Elsevier Ltd. All rights reserved.