title: Influence of support material on the immobilization of biomass for the degradation of linear alkylbenzene sulfonate in anaerobic reactors.
abstract: Two horizontal-flow anaerobic immobilized biomass reactors (HAIB) were used to study the degradation of the LAS surfactant: one filled with charcoal (HAIB1) and the other with a mixed bed of expanded clay and polyurethane foam (HAIB2). The reactors were fed with synthetic substrate supplemented with 14 mg l(-1)of LAS, kept at 30+/-2 degrees C and operated with a hydraulic retention time (HRT) of 12h. The surfactant was quantified by HPLC. Spatial variation analyses were done to quantify organic matter and LAS consumption along the reactor length. The presence of the surfactant in the load did not affect the removal of organic matter (COD), which was close to 90% in both reactors for an influent COD of 550 mg l(-1). The results of a mass balance indicated that 28% of all LAS added to HAIB1 was removed by degradation. HAIB2 presented 27% degradation. Molecular biology techniques revealed microorganisms belonging the uncultured Holophaga sp., uncultured delta Proteobacterium, uncultured Verrucomicrobium sp., Bacteroides sp. and uncultured gamma Proteobacterium sp. The reactor with biomass immobilized on charcoal presented lower adsorption and a higher kinetic degradation coefficient. So, it was the most suitable support for LAS anaerobic treatment.
authors.affiliation: Department of Hydraulics & Sanitation, School of Engineering of São Carlos, University of São Paulo, São Carlos, SP, Brazil. lorenaloliveira@yahoo.com.br
authors.forename: Lorena
authors.initials: L
authors.lastname: Lima de Oliveira
authors.forename: Iolanda Cristina
authors.initials: IC
authors.lastname: Silveira Duarte
authors.forename: Isabel Kimiko
authors.initials: IK
authors.lastname: Sakamoto
authors.forename: Maria Bernadete
authors.initials: MB
authors.lastname: Amâncio Varesche
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000145:classification / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D018533:Biomass; D019149:Bioreactors; D002849:Chromatography, Gas; D017931:DNA Primers; D016133:Polymerase Chain Reaction; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D017931:DNA Primers; D013501:Surface-Active Agents