Concentrations of Ag, In, Sn, Sb and Bi, and their chemical fractionation in typical soils in Japan

Abstract

We determined concentrations of Ag, In, Sn, Sb and Bi, and fractionated them by sequential extraction procedures, in five Japanese soils: Andosol-1 (grassland), Andosol-2 (forest), Cambisol (forest), Fluvisol (vegetable garden) and Regosol (forest). Average concentrations of Ag, In, Sn, Sb and Bi were 0.17 AE 0.08, 0.081 AE 0.019, 2.2 AE 0.5, 0.83 AE 0.32 and 0.32 AE 0.12 mg kg À1 , respectively. Average distributions of the chemical fractions (omitting those with an abundance < 5%) were: Ag, residualProportions of the mobilizable (exchangeable þ carbonate-bound þ MeOrg þ re-MeOx) metal fractions were in the order Sn ! Sb > Bi > Ag ffi In, and Cambisol > Andosol-2 > Regosol > Andosol-1 > Fluvisol. The proportions were predicted by multiple regression equations including pH, surface area, C contents, cation exchange capacity and clay content of the soils as independent variables (R 2 > 0.96, P < 0.02).

Acute Toxicity of Bismuth to the Earthworm &lt;i&gt;Eisenia andrei&lt;/i&gt;

“…In contrast, the results of this study showed that the fraction of Bi bioaccessible in soil, and consequently the fraction of Bi bioavailable to uptake by soils organisms increased despite the pH rise induced by earthworm activity. The rise in soil pH might increase the mobility of metals including Bi, due to an increase in the number of pH-dependent cation-exchange sites on the soil surface as suggested by Hou, et al [11]. Indeed, the present Bi study showed an increase in earthworm lethality with the increase of soil pH ( Fig.…”

“…This was not observed using the sandy soil, where nitric acid failed to dissolve the sand particles. The link between extractability of heavy metals from soil and the size of soil particles was reported earlier [11,41,42]. However, it is widely acknowledged that the total content of metals in soil is not a relevant parameter to determine potential risks from soil contamination.…”

“…Natural soil is a dynamic heterogeneous ecosystem characterized by having a complex environmental biogeochemical system that can play a critical role in determining the fate and ecological impact of pollutants on living organisms including earthworms. According to Hou, et al [11] the mobility and availability of Bi in soil is governed by its binding and interaction mechanisms with soil chemical constituents such as organic matter, carbonates, pH and other metal oxides. A previous soil column study, with Bi deposited on the soil surface and exposed to water precipitation for 18 months, showed that the metal is retained mostly within the top 0-2 cm of the column [12].…”

Molybdenum, Silver, Thallium and Vanadium

“…A sequential extraction scheme was used to investigate the Ag fractionation of five Japanese soils [68]. Mean concentrations of Ag in the chemical fractions were; 0.8 % exchangeable, 0.5 % carbonate bound, 20.9 % organically bound, 8.8 % oxide-bound, and 60.3 % residual.…”

Adsorption-Desorption of Lead and Tin in Soils

“…Moreover, they found that the major fraction of soil-sorbed Sn was associated with OM or Al/Fe-(hydro) oxide fractions. Hou et al (2006) showed that Sn occurred in relatively diverse fractions, and the concentrations of Sn in the residues were large in clay-rich soils. They found that the average proportions of the mobilizable (exchangeable, carbonate-bound, metal-organic complex, easily reducible metal oxide-bound) fractions of Sn was 36 ± 16%, whereas 40 ± 13% associated with the residues.…”