title: Treatment of linear alkylbenzene sulfonate in a horizontal anaerobic immobilized biomass reactor.
abstract: Linear alkylbenzene sulfonate (LAS) is an anionic surfactant widely used to manufacture detergents and found in domestic and industrial wastewater. LAS removal was evaluated in a horizontal anaerobic immobilized biomass reactor. The system was filled with polyurethane foam and inoculated with sludge that was withdrawn from an up flow anaerobic sludge blanket reactor that is used to treat swine wastewater. The reactor was fed with easily degradable substrates and a solution of commercial LAS for 313 days. The hydraulic retention time applied was 12h. The system was initially operated without detergent and resulted to 94% reduction of demand. The mass balance in the system indicated that the LAS removal efficiency was 45% after 18 0days. From the 109 th day to the 254 th day, a removal efficiency of 32% was observed. The removal of LAS was approximately 40% when 1500 mg of LAS were applied in the absence of co-substrates suggesting that the LAS molecules were used selectively. Microscopic analyses of the biofilm revealed diverse microbial morphologies and denaturing gradient gel electrophoresis profiling showed variations in the total bacteria and sulfate-reducing bacteria populations. 16S rRNA sequencing and phylogenetic analyses demonstrated that members of the order Clostridiales were the major components of the bacterial community in the last step of the reactor operation.
authors.affiliation: Federal University of São Carlos, Rodovia João Leme dos Santos, Km 110, 18052-780 Sorocaba, SP, Brazil. iolanda.duarte@gmail.com
authors.forename: I C S
authors.initials: IC
authors.lastname: Duarte
authors.forename: L L
authors.initials: LL
authors.lastname: Oliveira
authors.forename: N K
authors.initials: NK
authors.lastname: Saavedra
authors.forename: F
authors.initials: F
authors.lastname: Fantinatti-Garboggini
authors.forename: C B A
authors.initials: CB
authors.lastname: Menezes
authors.forename: V M
authors.initials: VM
authors.lastname: Oliveira
authors.forename: M B A
authors.initials: MB
authors.lastname: Varesche
mesh_terms: D017738:Alkanesulfonic Acids / Q000378:metabolism*; D000693:Anaerobiosis; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism; D018441:Biofilms; D018533:Biomass; D019149:Bioreactors; D003001:Cloning, Molecular; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012722:Sewage
chemical_list: D017738:Alkanesulfonic Acids; D012336:RNA, Ribosomal, 16S; D012722:Sewage; C030641:alkylbenzyl sulfonic acid