title: Kinetic studies of Cd (II) and Pb (II) ions biosorption from aqueous media using untreated and chemically treated biosorbents.
abstract: Untreated and chemically treated Albizia coriaria, Erythrina abyssinica and Musa spp. were studied in batch for uptake of Cd(2+) and Pb(2+) ions at pH 2.0-9.0 and agitation time of 30-390 min. Optimum biosorption conditions were pH 4 for Pb(2+) ions and pH 5 for Cd(2+) ions, contact time was 3.5 hours at 24 ± 1 °C for 10 mg/L biosorbent dosage and initial metal ions concentration of 20 mg/L. Chemical treatment had a 10-17% biosorption efficiency enhancement for Cd(2+) ions and a 1.6-2.3% reduction effect for Pb(2+) ions. The sorption capacities for Cd(2+) and Pb(2+) ions for treated biosorbents were 1.760-1.738 mg g(-1) compared to 1.415-1.539 mg g(-1) for untreated materials. The pseudo second-order model suitably fitted the Cd(2+) and Pb(2+) ions biosorption data with regression coefficients (R(2)) of 0.9784-0.9999. Fitting of the Ho model to the experimental data showed that the biosorption mechanism for both metal ions studied was mainly a chemisorption process. Therefore, treated A. coriaria, E. abyssinica and Musa spp. were potential biosorbents for remediation of Cd(2+) ions and the untreated materials suitable for removing Pb(2+) ions from contaminated aqueous media.
authors.affiliation: Department of Sustainable Development, Environmental Science and Engineering, Kungliga Tekniska Högskolan, Brinellvägen 28, SE-100 44 Stockholm, Sweden E-mail: gkba@kth.se; Department of Civil and Environmental Engineering, College of Engineering, Design, Art and Technology, Makerere University, Uganda.
authors.forename: G K
authors.initials: GK
authors.lastname: Bakyayita
authors.affiliation: Department of Sustainable Development, Environmental Science and Engineering, Kungliga Tekniska Högskolan, Brinellvägen 28, SE-100 44 Stockholm, Sweden E-mail: gkba@kth.se.
authors.forename: A C
authors.initials: AC
authors.lastname: Norrström
authors.affiliation: Water and Sanitation Department, African Development Bank, Tunis, Tunisia.
authors.forename: M
authors.initials: M
authors.lastname: Nalubega
authors.affiliation: Department of Civil and Environmental Engineering, College of Engineering, Design, Art and Technology, Makerere University, Uganda.
authors.forename: R N
authors.initials: RN
authors.lastname: Kulabako
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000737:chemistry*; D005638:Fruit / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007854:Lead / Q000737:chemistry*; D024301:Plant Bark / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; D002104:Cadmium; D014867:Water; D007854:Lead