A comparative study between the biofiltration for air contaminated with limonene or butyric acid using a combination of olfactometric, physico-chemical and genomic approaches

Abstract

A multidisciplinary analysis based on physico-chemical, olfactometric and microbiological perspectives was performed to compare the biofiltration of air contaminated with limonene or butyric acid. Two biofilters were subjected to butyric acid gaseous streams: one was filled with wood chips and sewage sludge compost (BF B-1) and the other with wood chips only (BF B-2). Similarly, two other biofilters were subjected to a gaseous stream containing limonene, with the same beds (BF L-1 and BF L-2, respectively). Although the biofilters fed with butyric acid received higher odor loads (280–3280 ouE/m2·s for BF B-1 and 135–1460 ouE/m2·s for BF B-2) than the biofilters treating limonene (30–170 ouE/m2·s for BF L-1 and 15–130 ouE/m2·s for BF L-2), the first systems achieved odor removal efficiencies greater than 90% during most of the biofiltration time, whereas in the limonene biofilters, these efficiencies never exceeded 70%. Regarding the packed beds, genomic analysis of the microbial communities showed a wider distribution of phyla (Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria) in compost-wood biofilters than in wood chips systems where Proteobacteria was clearly predominant. This study reveals the importance of considering both the nature of the biofiltered compounds and the packed bed composition in biofiltration operations.