title: Anaerobic degradation of linear alkylbenzene sulfonate (LAS) in fluidized bed reactor by microbial consortia in different support materials.
abstract: Four anaerobic fluidized bed reactors filled with activated carbon (R1), expanded clay (R2), glass beads (R3) and sand (R4) were tested for anaerobic degradation of LAS. All reactors were inoculated with sludge from a UASB reactor treating swine wastewater and were fed with a synthetic substrate supplemented with approximately 20 mg l(-1) of LAS, on average. To 560 mg l(-1) COD influent, the maximum COD and LAS removal efficiencies were mean values of 97+/-2% and 99+/-2%, respectively, to all reactors demonstrating the potential applicability of this reactor configuration for treating LAS. The reactors were kept at 30 degrees C and operated with a hydraulic retention time (HRT) of 18h. The use of glass beads and sand appear attractive because they favor the development of biofilms capable of supporting LAS degradation. Subsequent 16S rRNA gene sequencing and phylogenetic analysis of samples from reactors R3 and R4 revealed that these reactors gave rise to broad microbial diversity, with microorganisms belonging to the phyla Bacteroidetes, Firmicutes, Actinobacteria and Proteobacteria, indicating the role of microbial consortia in degrading the surfactant LAS.
authors.affiliation: Department of Hydraulics and Sanitation, School of Engineering of São Carlos, University of São Paulo, Av Trabalhador Sãocarlense 400, 13566-590 São Carlos, SP, Brazil. lorenaloliveira@yahoo.com.br
authors.forename: Lorena Lima
authors.initials: LL
authors.lastname: de Oliveira
authors.forename: Rachel Biancalana
authors.initials: RB
authors.lastname: Costa
authors.forename: Dagoberto Yukio
authors.initials: DY
authors.lastname: Okada
authors.forename: Daniele Vital
authors.initials: DV
authors.lastname: Vich
authors.forename: Iolanda Cristina Silveira
authors.initials: IC
authors.lastname: Duarte
authors.forename: Edson Luiz
authors.initials: EL
authors.lastname: Silva
authors.forename: Maria Bernadete Amâncio
authors.initials: MB
authors.lastname: Varesche
mesh_terms: D039903:Actinobacteria / Q000502:physiology; D017738:Alkanesulfonic Acids / Q000737:chemistry*; D000693:Anaerobiosis; D001419:Bacteria / Q000378:metabolism; D001673:Biodegradation, Environmental; D044822:Biodiversity; D018533:Biomass; D019149:Bioreactors; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D020560:Proteobacteria / Q000502:physiology; D012336:RNA, Ribosomal, 16S / Q000378:metabolism; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature; D013997:Time Factors
chemical_list: D017738:Alkanesulfonic Acids; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents; C030641:alkylbenzyl sulfonic acid