Location of trace elements in soil profiles: total and extractable contents of individual horizons

Abstract

Total contents of 29 trace and major elements and extractable contents of 20 elements were determined in the horizons of 4 profiles, 2 freely drained and 2 very poorly drained, of Scottish soils on drifts of basic igneous or granitic origin. The probable behaviour of other elements is suggested in the light of the results obtained. It is shown that in the course of pedological weathering, many elements are mobilised and become extractable by relatively weak reagents such as ammonium acetate (when readily exchangeable), dilute acetic acid (when less readily exchangeable or acid-soluble) or EDTA (when chelated or exchangeable). The forms in which different elements occur in the different horizons are assessed. In the surface horizons rich in organic matter many elements, such as Co, Ni, Fe, V, Cu, Cd, Sn and Pb, appear to occur mainly in chelated form; fewer, particularly Mn, are only in exchangeable form with plant uptake being largely responsible. Lower in the profiles the most common forms are acetic acid-soluble or, in gleyed horizons, exchangeable. In these horizons the degree of mobilisation is greater than in the corresponding freely drained horizons, the effect being most apparent for elements in readily weathered minerals.

A Review of the Different Methods Applied in Environmental Geochemistry For Single and Sequential Extraction of Trace Elements in Soils and Related Materials

“…Magnesium salts have been reported to have a somewhat stronger displacing action than those of calcium in the case of sorbed Co and Zn (Tessier et al 1979). Hydrogen ion in the form of 0.5 M acetic acid has been used in non-calcareous soils for copper (Berrow and Mitchell 1980) and for cobalt sorbed on iron oxyhydroxide sites (McLaren et al 1986). Acetic acid lacks specificity in that it partly attacks carbonate and silicate phases (Rapin and Forstner 1983).…”

“…Complexing extractants such as EDTA or DTPA can, by virtue of their strong complexing ability, displace metals from insoluble organic or organometallic complexes in addition to those sorbed on inorganic soil components (Berrow and Mitchell 1980;Ure and Davidson 2001).…”

Factors influencing metal bioavailability in soils: preliminary investigations for the development of a critical loads approach for metals

“…Berrow and Mitchell (1980) state that up to 99% of the metal content of soil solution may be present in complexed forms. Complexation may be in the form of chelation, where the complex forming ligands form two or more co-ordination bonds with the metal ion (Lindsay, 1979).…”

Heavy Metal Level in Soil, Water, Human Blood Samples and Potential Skin Allergy Risk Near Tanneries From Vellore District, India.

“…The physic-chemical parameters such as pH, TDS, turbidity, total alkalinity, iron, calcium, magnesium, zinc, aluminium, lead, chromium, Sulphates, chlorides, fluorides, nitrates and nitrates were determined, the chemical characteristics including heavy metals for examination of water [71,43]. The physic-chemical parameters were measured at the sample site using handheld analyzing kits.…”