title: Copper removal using a heavy-metal resistant microbial consortium in a fixed-bed reactor.
abstract: A heavy-metal resistant bacterial consortium was obtained from a contaminated river in São Paulo, Brazil and utilized for the design of a fixed-bed column for the removal of copper. Prior to the design of the fixed-bed bioreactor, the copper removal capacity by the live consortium and the effects of copper in the consortium biofilm formation were investigated. The Langmuir model indicated that the sorption capacity of the consortium for copper was 450.0 mg/g dry cells. The biosorption of copper into the microbial biomass was attributed to carboxyl and hydroxyl groups present in the microbial biomass. The effect of copper in planktonic cells to form biofilm under copper rich conditions was investigated with confocal microscopy. The results revealed that biofilm formed after 72 h exposure to copper presented a reduced thickness by 57% when compared to the control; however 84% of the total cells were still alive. The fixed-bed bioreactor was set up by growing the consortium biofilm on granular activated carbon (GAC) and analyzed for copper removal. The biofilm-GAC (BGAC) column retained 45% of the copper mass present in the influent, as opposed to 17% in the control column that contained GAC only. These findings suggest that native microbial communities in sites contaminated with heavy metals can be immobilized in fixed-bed bioreactors and used to treat metal contaminated water.
authors: Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77004, USA.
authors: Isis E Mejias
authors: IE
authors: Carpio
authors: Instituto de Ciências Biomédicas, Universidade de São Paulo, CEP 05508-000 São Paulo, SP, Brazil.
authors: Glaucia
authors: G
authors: Machado-Santelli
authors: Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), CEP 05508-000 São Paulo, SP, Brazil.
authors: Solange Kazumi
authors: SK
authors: Sakata
authors: Departamento de Engenharia Hidráulica e Ambiental, Escola Politécnica, Universidade de São Paulo, CEP 05508-000 São Paulo, SP, Brazil.
authors: Sidney Seckler
authors: SS
authors: Ferreira Filho
authors: Department of Civil and Environmental Engineering, University of Houston, Houston, TX 77004, USA. Electronic address: dfrigirodrigues@uh.edu.
authors: Debora Frigi
authors: DF
authors: Rodrigues
mesh_terms: D000327:Adsorption; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D001673:Biodegradation, Environmental / Q000187:drug effects; D018441:Biofilms / Q000187:drug effects; D019149:Bioreactors / Q000382:microbiology*; D001938:Brazil; D002606:Charcoal / Q000494:pharmacology; D003300:Copper / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D059013:Microbial Consortia / Q000187:drug effects; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature
chemical_list: D002606:Charcoal; D003300:Copper
keywords: Bacterial; Biofilm; Biosorption; Copper; Metal; Microbial consortia