title: Removal of triazine herbicides from aqueous systems by a biofilm reactor continuously or intermittently operated.
abstract: The impact of pesticide movement via overland flow or tile drainage water on the quality of receiving water bodies has been a serious concern in the last decades; thus, for remediation of water contaminated with herbicides, bioreaction systems designed to retain biomass have been proposed. In this context, the aim of this study was to evaluate the atrazine and terbutryn biodegradation capacity of a microbial consortium, immobilized in a biofilm reactor (PBR), packed with fragments of porous volcanic stone. The microbial consortium, constituted by four predominant bacterial strains, was used to degrade a commercial formulation of atrazine and terbutryn in the biofilm reactor, intermittently or continuously operated at volumetric loading rates ranging from 44 to 306 mg L(-1) d(-1). The complete removal of both herbicides was achieved in both systems; however, higher volumetric removal rates were obtained in the continuous system. It was demonstrated that the adjuvants of the commercial formulation of the herbicide significantly enhanced the removal of atrazine and terbutryn.
authors.affiliation: Departamento de Ingeniería Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. Carpio y Plan de Ayala, Col. Santo Tomás, México D.F. CP 11340, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Sánchez-Sánchez
authors.forename: D
authors.initials: D
authors.lastname: Ahuatzi-Chacón
authors.forename: J
authors.initials: J
authors.lastname: Galíndez-Mayer
authors.forename: N
authors.initials: N
authors.lastname: Ruiz-Ordaz
authors.forename: A
authors.initials: A
authors.lastname: Salmerón-Alcocer
mesh_terms: D001280:Atrazine / Q000378:metabolism*; D001419:Bacteria / Q000235:genetics / Q000378:metabolism; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D019149:Bioreactors / Q000382:microbiology*; D006540:Herbicides / Q000378:metabolism*; D059013:Microbial Consortia / Q000235:genetics; D014227:Triazines / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D006540:Herbicides; D014227:Triazines; D014874:Water Pollutants, Chemical; D001280:Atrazine; C010347:terbutryne
keywords: Arthrobacter; Atrazine degradation; Biofilm reactor; Herbicide adjuvants; Terbutryn degradation; Tezontle