TY - JOUR A1 - Santos, S. A1 - Costa, C. A. E. A1 - Duarte, A. C. A1 - Scherer, H. W. A1 - Schneider, Rudolf A1 - Esteves, V. I. A1 - Santos, E. B. H. T1 - Influence of different organic amendments on the potential availability of metals from soil: A study on metal fractionation and extraction kinetics by EDTA JF - Chemosphere N2 - The effects of long-term application of different organic amendments, as compared to mineral fertilizer, on Zn, Cu and Pb content and leachability in a luvisol derived from loess were assessed. The organic fertilizers, applied since 1962, were compost (COM) – from green organic household waste, sewage sludge (SLU) – from municipal water treatment facilities, farmyard manure (FYM) and the doses applied since 1997 were 90 t ha-1, 10 t ha-1 and 9 t ha-1, once in 3 years, respectively. The kinetics of metals extraction with 0.05 mol dm-3 EDTA at pH 6.0 has been studied. The two first-order reactions model was fitted to the kinetic data and allowed to distinguish two pools for each metal: a 'labile' fraction (Q1), quickly extracted with a rate constant k1, and a 'moderately labile' fraction (Q2), more slowly extracted, with a rate constant k2. Simultaneously, the pseudo-total metal contents in the soil samples were determined after digestion with aqua regia (3:1 HCl + HNO3). The obtained parameters Q1, k1, Q2, k2, for the kinetics of extraction of each metal in the three replicates of each fertilization mode, as well as the pseudo-total metal contents, were statistically analysed. COM and SLU application resulted in an increase of the total contents of Pb, Zn and Cu in soil. Further, the percentage of labile Zn and Pb also increased in consequence of the application of those amendments, particularly COM. The increase was more noticeable for Zn. FYM, despite not increasing the total content of Pb, Zn or Cu, did also have an effect on the leachability of Zn and Pb, increasing their labile fraction in soil. These results point to a potential risk of increasing metals mobility in soil, mainly Zn, associated to the use of organic amendments, particularly COM or SLU. KW - Compost KW - Sewage sludge KW - Soils KW - Metal mobility KW - EDTA KW - Kinetics PY - 2010 DO - https://doi.org/10.1016/j.chemosphere.2009.11.008 SN - 0045-6535 SN - 0366-7111 VL - 78 IS - 4 SP - 389 EP - 396 PB - Elsevier Science CY - Kidlington, Oxford AN - OPUS4-22187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -