title: Biosorption of radioactive thorium by Sargassum filipendula.
abstract: In the present work, the biosorption of radioactive thorium was investigated using a dry biomass of Sargassum filipendula as the biosorbent material. Radioactive solutions containing between 2.0 and 500.0 microg thorium were tested by biosorption with S. filipendula, yielding uptake capacities from 20 to 100%, depending on the concentration of the solution. Kinetic studies indicated that equilibrium between the thorium solution and the solid fraction was achieved after three hours of contact and that a second-order model could express the equilibrium kinetics. In order to investigate the maximum biosorption capacity of the biomass an isotherm was done, based on the experimental data, which revealed the maximum uptake capacity to be 2.59 micromol thorium/g biomass. The experimental data fitted well to a Langmuir model, which provided a good correlation between the experimental and predicted thorium uptake values.
authors.affiliation: Universidade do Estado do Rio de Janeiro, Instituto de Quimica, Programa de Pos-Graduacao em Engenharia Quimica--PPG-EQ. Rua Sao Francisco Xavier 524, Pavilhao Haroldo Lisboa da Cunha, Sala 400, Rio de Janeiro, Brazil, 20550-013.
authors.forename: Marta Cristina
authors.initials: MC
authors.lastname: Picardo
authors.forename: Ana Cristina
authors.initials: AC
authors.lastname: de Melo Ferreira
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Augusto da Costa
mesh_terms: D000042:Absorption; D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D049109:Cell Proliferation; D003198:Computer Simulation; D007220:Industrial Waste / Q000517:prevention & control; D007700:Kinetics; D008657:Metabolic Clearance Rate; D008954:Models, Biological; D044647:Sargassum / Q000254:growth & development* / Q000378:metabolism*; D013910:Thorium / Q000302:isolation & purification* / Q000493:pharmacokinetics*; D014462:Ultrafiltration / Q000379:methods*; D014873:Water Pollutants / Q000302:isolation & purification / Q000493:pharmacokinetics; D018508:Water Purification / Q000379:methods*
chemical_list: D007220:Industrial Waste; D014873:Water Pollutants; D013910:Thorium