title: Batch desorption studies and multiple sorption-regeneration cycles in a fixed-bed column for Cd(II) elimination by protonated Sargassum muticum.
abstract: The protonated alga Sargassum muticum was employed in batch desorption studies to find the most appropriate eluting agent for Cd(II)-laden biomass regeneration. Eleven types of eluting solutions at different concentrations were tested, finding elution efficiencies higher than 90% for most of the desorbents studied. Total organic carbon and biomass weight loss measurements were made. The reusability of the protonated alga was also studied using a fixed-bed column. Eleven consecutive sorption-regeneration cycles at a flow rate of 10 mL min(-1) were carried out for the removal of 50 mg L(-1) Cd(II) solution. A 0.1M HNO(3) solution was employed as desorbing agent. The column was operated during 605 h for sorption and 66 h for desorption, equivalent to a continuous use during 28 days, with no apparent loss of sorption performance. In these cycles, no diminution of the breakthrough time was found; although, a relative loss of sorption capacity, regarding the found in the first cycle, was observed. The slope of the breakthrough curves experiments a gradual increase reaching its maximum value for the last cycle tested (40% greater than for the first one). The maximum Cd(II) concentration elution peak was achieved in 5 min or less, and the metal effluent concentration was always lower than 0.9 mg L(-1) after 1 h of elution. The maximum concentration factor was determined to be between 55 and 109.
authors.affiliation: Departamento de Química Física e Enxeñería Química I, Universidade da Coruña, Alejandro de la Sota 1, 15008 A Coruña, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Lodeiro
authors.forename: R
authors.initials: R
authors.lastname: Herrero
authors.forename: M E
authors.initials: ME
authors.lastname: Sastre de Vicente
mesh_terms: D000327:Adsorption; D018533:Biomass; D002104:Cadmium / Q000302:isolation & purification* / Q000378:metabolism*; D011522:Protons; D044647:Sargassum / Q000378:metabolism*
chemical_list: D011522:Protons; D002104:Cadmium