Environmental Significance of Humic Acid in the Sequestration of Metals
Titel:
Environmental Significance of Humic Acid in the Sequestration of Metals
Auteur:
Misra, Virendra Pandey, Shri Dhar Viswanathan, P. N.
Verschenen in:
Chemistry & ecology
Paginering:
Jaargang 13 (1996) nr. 2 pagina's 103-112
Jaar:
1996-12-01
Inhoud:
Change in the fluorescence of humic acid was studied using various metals, such as iron, cadmium, chromium, mercury, manganese, nickel and lead, to test the significance of humic acid in the sequestration of metals. On keeping the concentration of humic acid fixed (10 μg) and varying the concentration of metals (1-40 μg), the following order of magnitude of quenching was noticed: Cu > Fe > Cr > Mn > Ni > Hg > Pb > Cd. However, humic acid concentration (1-40 μg) and metal concentration (10μg) showed a reverse trend. to test the humic acid-metal interaction in an aquatic system and on aquatic organisms such as fish, the LC50 values at 96 h for metals such as iron, copper, mercury, nickel and chromium were determined against common guppy fish (Poecilia reticulata). A 20 μg dose of humic acid showed a reduction in toxicity of metals towards fish as compared to a control exposed to metals only. the significance of results in relation to ionic interactions in ecotoxicology are discussed.