title: Heavy metal biosorption by gellan gum gel beads.
abstract: The Ni(2+) accumulation in batch mode from diluted solutions by gel beads of gellan gum (GG), alginate, kappa-carrageenan, agar, agarose, silica gel, polyacrylamide and two mixtures of GG+agar was investigated. All polymeric materials studied accumulated Ni(2+), but gel beads of GG were stable, easily obtainable and showed the highest Ni(2+) accumulation. The pH of the Ni(2+) solution was not critical for Ni(2+) accumulation. Accumulation of metals Cu(2+), Co(2+), Ni(2+), Pb(2+), Cd(2+) and Zn(2+) by GG gel beads reached the equilibrium after 24h. The removal of Pb(2+) and Cu(2+) from the aqueous solution was very efficient, with maximum metal uptake (q(max)) of 0.85 and 0.75 mmol/g dw GG, respectively. The general q(max) sequence was Pb>Cu>Ni approximately Zn=Co>Cd. In an equimolar metal mixture sorption experiment a clear reduction in accumulation was observed, except for Pb(2+) (30%). Heavy metals were desorbed with 100mM sodium citrate.
authors.affiliation: Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Spain.
authors.forename: Núria
authors.initials: N
authors.lastname: Lázaro
authors.forename: Asunción López
authors.initials: AL
authors.lastname: Sevilla
authors.forename: Susana
authors.initials: S
authors.lastname: Morales
authors.forename: Ana M
authors.initials: AM
authors.lastname: Marqués
mesh_terms: D000327:Adsorption; D003470:Culture Media; D019216:Metals, Heavy / Q000737:chemistry / Q000302:isolation & purification*; D011108:Polymers / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D003470:Culture Media; D019216:Metals, Heavy; D011108:Polymers; D011135:Polysaccharides, Bacterial; D014873:Water Pollutants; C048288:gellan gum