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 Limoges, PEIRENE, Equipe Développement d'indicateurs ou prévision de la qualité des eaux, URA IRSTEA, 123 Avenue Albert Thomas, 87060, Limoges Cedex, France.
J Environ Manage. 2019 May 15;238:159-165. doi: 10.1016/j.jenvman.2019.02.120. Epub 2019 Mar 6.
The use of digestate as amendment for agricultural soils has already been proposed as an alternative to mineral fertilizers or undigested organic matter. However, little information is available concerning the effect of digestate atmospheric exposure on trace elements speciation and, consequently, on their mobility and bio-accessibility when digestate is stored in open tanks or handled before land spreading. In this study, we investigated at laboratory-scale the effect of digestate aeration on the distribution of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se and W using the diffusive gradients in thin films technique (DGT)-based fractionation. For this purpose, experiments were performed to assess the variation in distribution between the labile, soluble and particulate fractions over time in digested sewage sludge during passive and forced aeration. Results showed that aeration promoted a dissolution of Al, As, Co, Cr, Cu, Fe, Mn, Mo and Pb, suggesting a possible increase in their mobility that may likely occur during storage in open tanks or handling before land spreading. Labile elements' fraction increased only during forced aeration (except for Fe and Mn), suggesting that their short-term bio-accessibility can increase only after significant aeration as the one assumed to occur when land spreading takes place.
将消化液作为农业土壤的改良剂已经被提议作为矿物肥料或未消化的有机物的替代品。然而，关于消化液在大气中的暴露对痕量元素形态的影响，以及在开放罐中储存或在土地施用前处理时它们的迁移性和生物可及性的信息很少。在这项研究中，我们使用薄膜扩散梯度技术（DGT）对痕量元素的形态进行了研究，研究了消化液曝气对 Al、As、Cd、Co、Cr、Cu、Fe、Mn、Mo、Ni、Pb、Sb、Se 和 W 分布的影响。为此，进行了实验以评估在被动和强制曝气期间，消化污水污泥中易变、可溶和颗粒分数之间的分布随时间的变化。结果表明，曝气促进了 Al、As、Co、Cr、Cu、Fe、Mn、Mo 和 Pb 的溶解，表明它们的迁移性可能增加，这可能在开放罐中储存或在土地施用前处理时发生。易变元素的分数仅在强制曝气期间增加（Fe 和 Mn 除外），这表明它们的短期生物可及性只有在发生显著曝气后才会增加，就像土地施用时假设的那样。
