Biosorption of nickel and total chromium from aqueous solution by gum kondagogu ( Cochlospermum gossypium): A carbohydrate biopolymer

• Published in: Journal of hazardous materials 2010-06, Vol.178 (1), p.851-860
• Main Authors: Vinod, V.T.P., Sashidhar, R.B., Sreedhar, B.
• Format: Article
• Language: English
• Subjects: Adsorption; Algorithms; Applied sciences; Biological and medical sciences; Biopolymers - chemistry; Biosorption mechanisms; Biotechnology; Bixaceae - chemistry; Carbohydrates - chemistry; Chemical engineering; Chromium; Chromium - isolation & purification; Cochlospermum gossypium; Electron Probe Microanalysis; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Gum kondagogu; Hydrogen-Ion Concentration; Ion exchange; Isotherm models; Kinetics; Mathematical models; Metal ions; Metals - chemistry; Methods. Procedures. Technologies; Nickel; Nickel - isolation & purification; Others; Pollution; Solutions; Spectrometry, X-Ray Emission; Spectroscopy, Fourier Transform Infrared; Thermodynamics; Total chromium; Toxic; Toxicology; Various methods and equipments; Water
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2010.02.016

Gum kondagogu ( Cochlospermum gossypium), an exudates tree gum from India was explored for its potential to decontaminate toxic metal ions in aqueous solution. The toxic metal ions nickel and total chromium biosorption capacity of the gum kondagogu were studied in the batch experimental mode. The optimum conditions of biosorption were determined by investigating pH, contact time, and initial metal ion and biosorbent concentrations. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and the data were analyzed on the basis of pseudo-second-order kinetic model. The maximum biosorption capacity of gum kondagogu as calculated by Langmuir model were found to be 50.5 mg g −1 for nickel at pH 5.0 ± 0.1 and 129.8 mg g −1 for total chromium at pH 2.0 ± 0.1, respectively. FTIR, SEM-EDXA and XPS analysis were used to evaluate the binding characteristics of gum kondagogu with metals. The experimental results demonstrate that the metal–ion interaction occurs through ion-exchange, adsorption and precipitation mechanisms.