title: Biodegradation of methyl tert-butyl ether by cometabolism with hexane in biofilters inoculated with Pseudomonas aeruginosa.
abstract: Biodegradation of methyl tert-butyl ether (MTBE) vapors by cometabolism with gaseous hexane (n-hexane > 95%) was investigated using Pseudomonas aeruginosa utilizing short chain aliphatic hydrocarbon (C(5)-C(8)). Kinetic batch experiments showed that MTBE was degraded even when hexane was completely exhausted with a cometabolic coefficient of 1.06 ± 0.16 mg MTBE mg hexane(-1). Intermediate tert-butyl alcohol (TBA) accumulation was observed followed by its gradual consumption. A maximum MTBE elimination capacity (EC(MAX)) of 35 g m(-3) h(-1) and removal efficiency (RE) of 70% were attained in mineral medium amended biofilters having an empty bed residence time (EBRT) of 1 min. For these experimental conditions, a maximum hexane EC of approximately 60 g m(-3) h(-1) was obtained at a load of 75 g m(-3) h(-1). Experiments under transient conditions revealed a competitive substrate interaction between MTBE and hexane. Biomass densities between 5.8 and 12.6 g L(biofilter) (-1) were obtained. Nevertheless, production of biopolymers caused non-uniform distribution flow rates that reduced the performance. Residence time distribution profiles showed an intermediate dispersion flow rate with a dispersion coefficient of 0.8 cm(2) s(-1).
authors.affiliation: Universidad Autónoma Metropolitana-Cuajimalpa, Departamento de Procesos y Tecnología, México, Distrito Federal, México.
authors.forename: Margarita
authors.initials: M
authors.lastname: Salazar
authors.forename: Marcia
authors.initials: M
authors.lastname: Morales
authors.forename: Sergio
authors.initials: S
authors.lastname: Revah
mesh_terms: D000393:Air Pollutants / Q000378:metabolism*; D000473:Alkanes / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019149:Bioreactors; D002849:Chromatography, Gas; D005374:Filtration; D005742:Gasoline / Q000032:analysis; D006586:Hexanes / Q000378:metabolism; D007700:Kinetics; D008738:Methyl Ethers / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000378:metabolism*
chemical_list: D000393:Air Pollutants; D000473:Alkanes; D005742:Gasoline; D006586:Hexanes; D008738:Methyl Ethers; C043243:methyl tert-butyl ether