title: By-passing acidification limitations during the biofiltration of high formaldehyde loads via the application of ozone pulses.
abstract: A formaldehyde airstream was treated in a biofilter for an extended period of time. During the first 133 days, the reactor was operated without ozone, whereas over the following 82 days ozone was intermittently implemented. The maximum stable elimination capacity obtained without ozone was around 57 g m(-3) h(-1). A greater load could not be treated under these conditions, and no significant formaldehyde removal was maintained for inlet loads greater than 65 g m(-3) h(-1); the activity of microorganisms was then inhibited by the presence of acidic byproducts, and the media acidified (pH<4). The implementation of ozone pulses allowed a stable elimination capacity to be obtained, even at greater loads (74 g m(-3) h(-1)). The effect of ozone on the extra cellular polymeric substances detachment from the biofilm could not be confirmed due to the too low biofilter biomass content. Thus, the results suggest that ozone acted as an in situ pH regulator, preventing acidic byproducts accumulation, and allowing the treatment of high loads of formaldehyde.
authors.affiliation: División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica (IPICyT), Camino a la Presa San José 2055, Col. Lomas 4ª Sección, San Luis Potosí, SLP 78216, Mexico.
authors.forename: Teresa
authors.initials: T
authors.lastname: García-Pérez
authors.forename: Aitor
authors.initials: A
authors.lastname: Aizpuru
authors.forename: Sonia
authors.initials: S
authors.lastname: Arriaga
mesh_terms: D000393:Air Pollutants / Q000378:metabolism*; D018533:Biomass; D001704:Biopolymers / Q000378:metabolism; D019149:Bioreactors; D005374:Filtration; D005557:Formaldehyde / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D016877:Oxidants / Q000737:chemistry*; D010126:Ozone / Q000737:chemistry*
chemical_list: D000393:Air Pollutants; D001704:Biopolymers; D016877:Oxidants; D005557:Formaldehyde; D010126:Ozone
keywords: Biofiltration; Extracellular polymeric substances; Formaldehyde; Ozone pulses; W/O(3); pH; without ozone