Residual copper(II) complexes in purified soil and sewage sludge fulvic acids: electron spin resonance study

Conference · · Soil Sci. Soc. Am. J.; (United States)

OSTI ID:6293707

Senesi, N; Sposito, G

Electron spin resonance (ESR) spectra were obtained for both frozen (77 K) aqueous solutions and solid samples of purified fulvic acid (FA) extracted from sewage sludge and from soil organic matter. Large scan range (5000 G) ESR spectra indicated the presence of organic free radical species of semiquinone nature and of iron(III) in sites of highly rhombic character. Narrower scan range (2000 G) ESR spectra were characterized by absorptions of the axial type near g = 2, which indicated the presence of residual copper(II) in a d/sub x2 - y2/ groundstate complexed with ligands arranged in a tetragonal environment. The ESR parameters for the sludge FA samples indicated that the main resonances were consistent with a 3 O-1 N-binding site and the minor ones with 4 O - or 2 O - and 2 N-coordinating environments. ESR spectra of the sludge FA run over a very narrow scan range (1000 G) suggested that an intensely structured pattern at g/sub perpendicular to/ could be assigned to a superhyperfine coupling of the unpaired Cu electron to two equivalent N ligand nuclei.

• Research Organization: Universita di Bari, Italy
• OSTI ID: 6293707
• Conference Information: Journal Name: Soil Sci. Soc. Am. J.; (United States) Journal Volume: 48:6
• Country of Publication: United States
• Language: English

Related Subjects

510200* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
BIOCHEMISTRY
CHEMISTRY
COMPLEXES
COPPER
ELECTRON SPIN RESONANCE
ELEMENTS
FULVIC ACIDS
IRON
LIGANDS
MAGNETIC RESONANCE
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC MATTER
RESONANCE
SEWAGE
SEWAGE SLUDGE
SLUDGES
SOIL CHEMISTRY
SOILS
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENTS
WASTES