title: Removal of the sesquiterpene β-caryophyllene from air via biofiltration: performance assessment and microbial community structure.
abstract: Experiments were conducted in a laboratory-scale biofilter to assess the ability of a fixed-film biological process to treat an air stream containing β-caryophyllene, a sesquiterpene emitted by a variety of conifer trees as well as industrial wood processing operations. Treatment performance was evaluated under a variety of pollutant loading conditions and nutrient supply rates over an operational period lasting more than 240 days. At empty bed contact times (EBCTs) as low as 10 s and daily average pollutant loading rate as high as 24.2 g C/(m(3) h) (grams pollutant measured as carbon per cubic meter packed bed volume per hour), removal efficiencies in excess of 95 % were observed when sufficient nutrients were supplied. Results demonstrate that, as with biofilters treating other compounds, biofilters treating β-caryophyllene can experience local nutrient limitations that result in diminished performance. The biofilter successfully recovered high removal efficiency within a few days after resumption of pollutant loading following a 14-day interval of no contaminant loading. Construction of a 16S rRNA gene library via pyrosequencing revealed the presence of a high proportion of bacteria clustering within the genera Gordonia (39.7 % of the library) and Rhodanobacter (37.6 %). Other phylotypes detected at lower relative abundances included Pandoraea (6.2 %), unclassified Acetobacteraceae (5.5 %), Dyella (3.3 %), unclassified Xanthomonadaceae (2.6 %), Mycobacterium (1.8 %), and Nocardia (0.6 %). Collectively, results demonstrate that β-caryophyllene can be effectively removed from contaminated gas streams using biofilters.
authors.affiliation: Department of Civil and Environmental Engineering, Louisiana State University, 3515B Patrick Taylor Hall, Baton Rouge, LA, 70803, USA. moemwil@lsu.edu
authors.forename: William M
authors.initials: WM
authors.lastname: Moe
authors.forename: Weili
authors.initials: W
authors.lastname: Hu
authors.forename: Trent A
authors.initials: TA
authors.lastname: Key
authors.forename: Kimberly S
authors.initials: KS
authors.lastname: Bowman
mesh_terms: D000393:Air Pollutants / Q000302:isolation & purification*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001673:Biodegradation, Environmental; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D059013:Microbial Consortia; D000081223:Polycyclic Sesquiterpenes; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012717:Sesquiterpenes / Q000302:isolation & purification*; D055549:Volatile Organic Compounds / Q000032:analysis
chemical_list: D000393:Air Pollutants; D000081223:Polycyclic Sesquiterpenes; D012336:RNA, Ribosomal, 16S; D012717:Sesquiterpenes; D055549:Volatile Organic Compounds; C024714:caryophyllene