University of Paris-Est, Laboratoire Géomatériaux et Environnement (EA 4508), UPEM, 77454 Marne-la-Vallée, France; University of Limoges, PEIRENE, Equipe Développement d'indicateurs ou prévision de la qualité des eaux, URA IRSTEA, 123 Avenue Albert Thomas, 87060 Limoges Cedex, France; University of Cassino and Southern Lazio, Department of Civil and Mechanical Engineering, via Gaetano di Biasio 43, 03043 Cassino (FR), Italy.
University of Limoges, PEIRENE, Equipe Développement d'indicateurs ou prévision de la qualité des eaux, URA IRSTEA, 123 Avenue Albert Thomas, 87060 Limoges Cedex, France.
Talanta. 2019 Jan 15;192:204-211. doi: 10.1016/j.talanta.2018.09.033. Epub 2018 Sep 12.
This study proposes an evaluation of the diffusive gradients in thin films technique (DGT) for studying trace elements in digested sewage sludge samples. Twelve elements were monitored by Chelex (Al, Cd, Co, Cr (III), Cu, Fe, Mn, Ni, Pb) and zirconia-DGT (As, Mo, Se) samplers exposed from 4 h to 9 days. Twenty-four hours' deployment time was suitable for most of the studied elements. However, short deployment led to insufficient element accumulation or non-establishment of steady state while long deployment (from 18 to 144 h depending on the element) led to saturation of the binding gels and/or competing effects with other major elements. In addition, this study showed that the matrix of the digested sewage sludge lowers the accumulation of some trace elements in the DGT samplers, leading to labile concentrations underestimation of roughly 10-30% (depending on the element). Moreover, compared to the conventional total dissolved elements measurement, DGT technique allowed to quantify 7 out of 12 labile elements whereas only 3 out of 12 dissolved elements were quantified. These results highlight the potential of DGT technique to assess labile trace elements in digestate samples, provided a careful adaptation of the deployment time as well as an evaluation of the matrix effect is performed.
本研究提出了一种评估薄膜扩散梯度技术（DGT）用于研究消化污泥样品中痕量元素的方法。使用 Chelex（Al、Cd、Co、Cr(III)、Cu、Fe、Mn、Ni、Pb）和氧化锆-DGT（As、Mo、Se）采样器监测了 12 种元素，暴露时间从 4 小时到 9 天不等。24 小时的部署时间适用于大多数研究元素。然而，较短的部署时间会导致元素积累不足或未达到稳定状态，而较长的部署时间（根据元素的不同，从 18 小时到 144 小时不等）则会导致结合凝胶饱和和/或与其他主要元素发生竞争效应。此外，本研究表明，消化污泥的基质会降低 DGT 采样器中一些痕量元素的积累，导致可利用浓度低估约 10-30%（取决于元素）。此外，与传统的总溶解元素测量相比，DGT 技术能够定量测定 12 种可利用元素中的 7 种，而仅能定量测定 12 种溶解元素中的 3 种。这些结果表明，DGT 技术有潜力评估消化物样品中的可利用痕量元素，但需要谨慎调整部署时间，并评估基质效应。
