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

Abstract

Reviewing the current state of knowledge about sequential extraction applied for soil vanadium (V) fractionation, we identified an urgent requirement of an sequential extraction (SE) specified for V. Namely, almost all previous SE extracted only 8.4%-48% of total V in soils (excluding residue). Thus, we proposed an eight-step SE for V fractionation in soils according to the knowledge gained from literature and our own dissolution experiments with model minerals. After extracting the mobilisable and adsorbed V with de-ionised water and 5mmol/L phosphate, 1mol/L pyrophosphate was applied to gather organic matter bound V which minimised the artefact dissolving Al and Fe (hydr)oxides occurred when using HNO-HO for extraction. Extraction with 0.4mol/L NHOH⋅HCl was highly selective toward manganese oxides. Fractionation of different crystalline Al and Fe (hydr)oxides associated V with 1mol/L HCl, 0.2mol/L oxalate buffer and 4mol/L HCl at 95°C especially improved the extractability of V incorporated with crystalline phase associated V. The suitability of our new SE scheme was confirmed by its higher selectivity against the target phases and higher extraction efficiencies (55%-77% of total V) with model minerals and 6 soils of different properties than previous SE.

Copper Analysis by Two Different Procedures of Sequential Extraction after Electrodialytic Remediation of Mine Tailings

“…This procedure allows distinguishing between: water-soluble fractions, exchangeable fractions, oxy-hydroxides and oxides of Fe(III) in different steps, organic and secondary Cu-sulfide fractions, primary sulfide and residual silicate fractions. The optimization of the method has been developed for the analysis of arsenic, copper and vanadium, among others [21,22,23].…”

Prediction of Metals Bioavailability in the Soils of O’kiep, South Africa

“…The presence of HM in an environment have a significant impact on plant functionality in an ecosystem as a result of their accumulation potential including toxicity with some having shown to cause cellular damage in plants and animal cells [4]. The environmental risks of metal(loid)s is primarily associated with their chemical forms or the type of their binding forms and reactivity [5], [6], with metal speciation being vital to the assessment of environmental risks, particular in various matrices such as water, dust, air, soil and sediments [3], [7]. The understanding of these risks is a prerequisite for the development of suitable remediation strategies [8].…”