Bioavailability of Vanadium Extracted by EDTA, HCl, HOAC, and NaNO3 in Topsoil in the Panzhihua Urban Park, Located in Southwest China

Abstract

Bioavailable vanadium was evaluated on the basis of soil vanadium single-extraction with ethylenediaminetetraacetic acid (EDTA), hydrochloric acid (HCl), acetic acid (HOAc), and sodium nitrate (NaNO(3)) in Panzhihua urban park. The soil vanadium concentration extracted by HOAc was 0.01-2.07 mg kg(-1), by EDTA 0.28-7.03 mg kg(-1), by NaNO(3) 0.07-0.53 mg kg(-1), and by HCl 0.19-1.36 mg kg(-1). The bioavailable vanadium (bioavailable fraction) obtained with HOAc was 0.01-1.33%, with EDTA 0.27-4.09%, with NaNO(3) 0.13-0.72%, and with HCl 0.06-0.28%. In addition, the impact of soil properties, soil nutrients, and soil enzyme activities on bioavailability of vanadium is discussed in this study. Based on the characteristics of bioavailable vanadium in the soil, ecological and health risks should have been given more attention in the studied area.

Vanadium fractionation by the BCR procedure from arable soils of the Siedlce upland region / Wanad we frakcjach wydzielonych metodą BCR w glebach uprawnych wysoczyzny siedleckiej

“…The content of this element in the fractions F1 and F3 was significantly correlated with carbon in the organic complexes C org (0.466-0.567 and 0.440-0.550) and with the reaction (pH) of soil ( 0.835 and 0.858; 0.719 and 0.807). Similar relations have been also reported by Ovari et al [2001], Połedniok and Buhl [2003], Teng et al [2011] and Jeske and Gworek [2012].…”

“…The smallest quantity of vanadium was detected in the bioavailability, exchangeable fraction F1 0.4-1.3% (Eutric Cambisols); 0.5-2.1% (Haplic Luvisols) and 0.5-3.3% (Stagnic Luvisols) (Table 2). The high concentration of vanadium in this fraction in the soil environment may be toxic to plants and animals, especially at a low reaction pH [Kabata-Pendias, Pendias 1999, Crans et al 2004, Teng et al 2011. The significant value (p < 0.01) of the correlation coefficient r (from 0.835 to 0.858) indicates a close correlation between the content of vanadium in the fraction F1 and the value of pH in the examined soil types (Table 3) have highlighted a significant role of very durable organic-mineral and mineral complexes in the speciation of vanadium; these authors detected 57.4-85.5% of this element in the durable complexes of the residual fraction in uncontaminated soil.…”

Mechanism for Photopromoted Release of Vanadium from Vanadium Titano-Magnetite

“…As the most important base of V production in the world, the giant Panzhihua vanadium titanium magnetite deposit provides 64% of V for China. Extensive mining and smelting activities have had major environmental impacts in mines or nearby regions, resulting in abnormally elevated concentrations of V in the water and soil near mines or smelting sites. − When these minerals are exposed to water environment under solar light irradiation, the release rate of V can be accelerated, and the release amount of V increased by the photocatalysis process of magnetite. Low toxic and immobile V­(III) and V­(IV) are oxidized to highly toxic and mobile V­(V) during the process, which enhanced the environmental risk of V. As the starting point of biogeochemistry cycle of V, this study on the dissolution of the most important V containing minerals helps us to understand the pollution problem of V. This study, as a part of a broader study on the release behavior of V, is a premise that helps us to understand the migration and transformation behavior of V in the presence of other important factors, such as natural organic ligands, in the natural environment.…”

An optimised sequential extraction scheme for the evaluation of vanadium mobility in soils

“…The use of lower phosphate concentration and shortage of the extraction duration may minimise to extract organic matter associated V. Namely, phosphate is capable of complexation with polyvalent cations, e.g., Ca 2+ , Al 3+ and Fe 3+ , which are responsible for maintaining organic matter in a flocculated and insoluble state in soils, however weaker than pyrophosphate (Lente et al, 2000). Both acetic acid (HOAc) and EDTA were also common reagents for quantifying mobilisable and bioavailable metal(loid)s (Teng et al, 2011b;Tian et al, 2014). However, HOAc was insufficient to release the adsorbed vanadate since it only slightly lowered the pH and almost did not change the adsorption affinity of vanadate to soil particles (Tian et al, 2014).…”