Speciation of waste water sediments (dedikált példány) [antikvár]

Speciation of waste water sediments Gy. Heltai3'*, K. Percsichb, I. Fekete3, B. Barabásb, T. Józsab 1 Department of Chemistry and Biochemistry, Gödöllő University of Agricultural Sciences, H-2103 Gödöllő, Hungary hCentral Analytical Laboratory, Gödöllö University of Agricultural Sciences, H-2103 Gödöllő, Hungary Abstract A sequential extraction procedure for waste water sediments was elaborated based on CO-, and water extractants using supercritical fluid extraction instrumentation. The procedure gives information on water-soluble, carbonate-bound and mobile organic-bound trace metal fractions. The chemical interpretation of this procedure is comparable with the BCR recommended three-stage sequential extraction. The validation of the proposed procedure requires more detailed investigations. © 2000 Elsevier Science B.V. All rights reserved. Keywords: Speciation analysis; Sequential extraction; Supercritical extraction; Waste water sediment; Elemental species 1. Introduction Modelling of biogeochemical cycles of elements — which is often necessary for agrochemical or environmental purposes — requires the chemical speciation, i.e. the clear identification and quantification of the element species in real environmental samples (matrices) [1], In agrochemical practice functional speciation has a long tradition: soil fertility is characterized by determining the 'plant-available' forms of total nutrient element content. Plant uptake in this approach is modelled by single-step chemical extraction. A * Corresponding author. large variety of such extraction procedures has been introduced to support plant nutrition advisory systems. In Hungary the recently applied single-step extraction standards for trace metal speciation in soils are listed in Table 1 [2-5], In environmental analysis of soils and sediments, however, operationally defined speciation has become the dominant approach. In this case the species are defined by the procedure used to isolate them [6], A large number of sequential extraction procedures have been developed in which the element content is partitioned by sequential treatment with a series of reagents [7], It was only a few years ago that an attempt was made to harmonize methodologies for sequential extraction tests between EU member states [8]. 0026-265X/00/S - see front matter © 2000 Elsevier Science B.V. All rights reserved. PII: S0026-265X(00)00095-3