Chemical partitioning of aluminium in rocks, soils, and sediments acidified by mining activity

Abstract

The work presented describes the application of different analytical approaches for study of aluminium mobility in rock, soil, and sediment samples affected by mining activity (secondary quartzites with sulfidic deposits). For this purpose we used a combination of the single extractions, the optimized BCR three-step sequential extraction procedure (SEP), and reactive aluminium determination after chelating ion-exchange on Ostsorb (Iontosorb) Salicyl by a batch technique with flame atomic absorption spectrometry quantification. The single extraction agents H(2)O, KCl, NH(4)Cl, and BaCl(2) were found to be the best for the quantitative estimation of the aluminium mobility in rocks, soils, and sediments caused by acidification of the environment. This fact was confirmed by reactive aluminium determination in the same samples. The vast majority of the aluminium content of samples after application of the optimized BCR three-step SEP is in the residues. The available fraction of aluminium extracted by dilute CH(3)COOH in the first step of this procedure correlates with the reactive aluminium content. The amounts of aluminium released in the second and the third steps and the sums from steps 1-3 of this procedure are closely associated with the aluminium content values obtained by the single dilute HCl leach. The accuracy of results obtained was verified with only informative values for individual fractions of the BCR three-step SEP because of the absence of suitable certified or standard reference materials. The amounts of the reactive aluminium determined in samples was in the range 12-82% of total soluble Al in the filtered H(2)O extracts. It was confirmed that the acidified polluted samples contain the most of reactive Al content, which is responsible for its toxicity.

Status of aluminium in environmental compartments contaminated by acidic mine water

“…For the sediment samples, the improved BCR sequential extraction procedure [30,31] was used to separate the following three Al fractions: (a) 0.11 M HCH 3 COO-extractable metal (termed as Fraction I), (b) 0.5 M NH 2 OH·HCl-extractable metal (termed as Fraction II) and (c) 1 M NH 2 CH 3 COO-extractable metal after 30% H 2 O 2 digestion (termed as Fraction III). The Al concentration in various extracts was determined by ICP-OES.…”

Evaluation of separation and determination of phytoavailable and phytotoxic aluminium species fractions in soil, sediment and water samples by five different methods

“…The sequential extraction procedure was applied to soil and sediment samples using the optimised BCR SEP [7][8][9]11,13] (first acid extractable step: 40 ml 0.11 M acetic acid solution (AA), second reducible step: 0.5 M NH 2 OH AE HCl in 0.05 M HNO 3 solution (2), third oxidizable step: H 2 O 2 followed by 1 M ammonium acetate solution adjusted to pH 2.0 by HNO 3 (3), the residue was decomposed by 15HF + 5HNO 3 + 2HClO 4 + 1H 2 O 2 hot mixture in open system [28,29]). The BCR SEP specific fraction precision, repeatability and accuracy were validated by the application of BCR SEP to soil, sediment and rock RMs (see Section 2.3) in previously published works [7-9,11,13].…”

“…The operational and/or functional nature of Al fractionation means that it is very hard to compare the results obtained by different laboratories using different protocols [1][2][3][4][5][6][7][8][9][10][11][12][13]. Therefore, the protocol harmonization and standardization are needed to enable the wider comparison studies for various Al species fractions.…”

“…Analogically, the functionally defined fractions contain the Al species defined by their environmental, physiological or clinical effects or some other function, e.g. their mobility, phytoavailability or phytotoxicity [1][2][3][4][5][6][7][8][9][10][11][12][13]. These main Al research subjects are extremely influenced by the environment pH value and presence of inorganic and organic complexing compounds.…”

Efficient preconcentration and determination of traces of aluminum ion using silica-bonded glycerol sorbent

“…Different solid-phase extraction methods have been recommended * Corresponding author. for the determination of aluminum [24][25][26][27][28]. However, many of these methods do not provide high preconcentration factors.…”