ISSN:
1573-2932
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract Copper, Fe, and Mn were used as probes to investigate residual metal reactivity for humic acid (HA) samples extracted from a loam soil, either non-amended or amended with anaerobically digested sewage sludge for 4, 5, 6, or 7 yr at 90 t ha−1. yr−1. Irrespective of their origin, the HA complexes significant amounts of metal, in forms stable against intense water-leaching, in the order Fe 〉 Cl 〉 Mn. Sludge-amended soil HA adsorbed and retained Fe in amounts greater than HA extracted fron non-amended soil. Metal adsorption occurred mainly by cation-exchange replacement of metals previousl: bound to HA. Water-stable Fe3+-HA complexes prepared in the laboratory were partially stable agains H+ and metal ion exchange reactions, whereas Cu2+ and Mn2+ in laboratory-prepared, water-stabl HA complexes were desorbed almost completely by these two reactions. Electron spin resonance spectra indicated that the laboratory-prepared metal-HA complexes had a chemical composition and molecula structure similar to that of indigenous metal-HA complexes, which were stable against all leachin, and cation-exchange treatments. Although the HA samples showed a maximal metal binding (i.e. saturation) as metal loading of the sludge-amended soil increased, they still exhibited a high residua binding capacity for the three metals used as probes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00211203
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