Speciation of heavy metals in water from the Uganda side of Lake Victoria

• Published in: International journal of environmental studies 2010-02, Vol.67 (1), p.9-15
• Main Authors: Mbabazi, Jolocam, Twinomuhwezi, H., Wasswa, J., Ntale, M., Mulongo, G., Kwetegyeka, J., SchrǾder, K.H.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Atomic absorption spectrophotometry; Biological and medical sciences; Cadmium; Cationic; Conservation, protection and management of environment and wildlife; Copper; Dialysis; Ecotoxicology, biological effects of pollution; Freshwater; Fundamental and applied biological sciences. Psychology; General aspects; Heavy metals; Ion-exchange; Lake Victoria; Lakes; Lead (metal); Speciation; Zinc
• ISSN: 0020-7233; 1029-0400
• DOI: 10.1080/00207230903371783

Different forms of copper Cu, zinc Zn, lead Pb and cadmium Cd in water from the Uganda side of Lake Victoria (25°C, pH 6.75-7.18), the second largest inland freshwater lake in the world, have been studied using ion-exchange, dialysis and atomic absorption spectrophotometry. The results indicate that heavy metals Cu, Zn, Pb and Cd are present mainly in the cationic form (80-83%). Small quantities of anionic (13-22%), non-ionic, dialyzable (4-8%), and non-ionic, non-dialyzable (< 1.3-4.4%) forms were also detected for all metals except Cd. The corresponding concentrations lay in the ranges: cationic, 0.06-0.99; anionic, < 0.001-0.25; non-ionic, dialyzable, < 0.001-0.08; non-ionic, non-dialyzable, < 0.001-0.06 µg ml −1 . The existence of the metals in non-ionic and non-dialyzable forms is attributable to metal associations with high relative molecular mass (RMM) organic matters.