title: Evaluation of clay aggregate biotrickling filters for treatment of gaseous emissions from intensive pig production.
abstract: Treatment of ventilation air from livestock production by biological airfiltration has emerged as a cost-effective technology for reduction of emissions of odorants and ammonia. Volatile sulfur compounds from livestock production include H2S and methanethiol, which have been identified as potentially important odorants that are not removed sufficiently by biological air filters. Light-expanded clay aggregates (Leca(®)) is a biotrickling filter material that contains iron oxides, which can oxidize H2S and methanethiol, and thus potentially may help to remove these two compounds in biological air filters. This study used on-line PTR-MS measurements to investigate the performances of two Leca(®) biotrickling filters (abraded Leca(®) filter and untreated Leca(®) filter) for removal of odorants and ammonia emitted from an experimental pig house. The results indicated that the abraded Leca(®) filter had a similar or slightly better capability for removing odorants than the untreated Leca(®) filter. This may be due to the enlargement of the surface area by the friction process. The volatile sulfur compounds, however, were not removed efficiently by either of the two Leca(®) filters. Kinetic analysis of a ventilation controlled experiment during the first period indicated that Grau second-order kinetics could be applied to analyze the removal of sulfur compounds and other odorants, whereas the Stover-Kincannon model could only be applied to analyze the removal of odorants other than sulfur compounds, partly due to the limitation of mass transfer of these compounds in the biotrickling filters. In the last measurement period, a production of dimethyl disulfide and dimethyltrisulfide coinciding with strongly enhanced removal of methanethiol was observed for the untreated filter. This was assumed to be enhanced by an incidence of low local air velocity in the filter and indicated involvement of iron-catalyzed reactions in the removal of sulfur compounds.
authors.affiliation: Department of Engineering, Faculty of Science and Technology, Aarhus University, Hangøvej 2, Aarhus N 8200-DK, Denmark.
authors.forename: Dezhao
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Food Science, Faculty of Science and Technology, Aarhus University, Blichers Allé 20, Tjele 8830-DK, Denmark.
authors.forename: Mette Marie
authors.initials: MM
authors.lastname: Løkke
authors.affiliation: Danish Agriculture & Food Council, Pig Research Centre, Axeltorv 3, Copenhagen V 1609-DK, Denmark.
authors.forename: Anders Leegaard
authors.initials: AL
authors.lastname: Riis
authors.affiliation: Saint-Gobain Weber A/S, Randersvej 75, Hinge, Randers SV 8940-DK, Denmark.
authors.forename: Knud
authors.initials: K
authors.lastname: Mortensen
authors.affiliation: Department of Engineering, Faculty of Science and Technology, Aarhus University, Hangøvej 2, Aarhus N 8200-DK, Denmark. Electronic address: af@eng.au.dk.
authors.forename: Anders
authors.initials: A
authors.lastname: Feilberg
mesh_terms: D000538:Aluminum Silicates; D000641:Ammonia / Q000737:chemistry; D000818:Animals; D000077215:Clay; D004220:Disulfides / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005374:Filtration; D006862:Hydrogen Sulfide / Q000737:chemistry; D058751:Livestock; D009812:Odorants; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013552:Swine; D055549:Volatile Organic Compounds / Q000737:chemistry; D018505:Waste Management / Q000379:methods*
chemical_list: D000538:Aluminum Silicates; D004220:Disulfides; D005290:Ferric Compounds; D013438:Sulfhydryl Compounds; D055549:Volatile Organic Compounds; C000499:ferric oxide; C005231:methylmercaptan; C021181:dimethyl disulfide; D000641:Ammonia; D000077215:Clay; D006862:Hydrogen Sulfide
keywords: Biological air filter; Hydrogen sulfide; Methanethiol; Odor; PTR-MS