Fine scale measurement and mapping of uranium in soil solution in soil and plant-soil microcosms, with special reference to depleted uranium

Abstract

Background and aims Residues from use of depleted uranium (DU) munitions pose a lasting environmental impact through persistent contamination of soils. Consequently, an understanding of the factors determining the fate of DU in soil is necessary. An understudied factor is the interaction of root exudates with DU. This study describes the use of 'Single-Cell-Sampling-and-Analysis' (SiCSA) for the first time in soil and investigates the effects of root exudates on DU dissolution. Methods Soil solutions from soil and plant-soil microcosms containing DU fragments were sampled and analysed using SiCSA and capillary electrophoresis/ ICP-MS for organic acids and uranium. Results Nanolitre volumes of soil solution were sampled and analysed. Soils with DU fragments but no citrate addition showed low uranium concentrations in

Biogeochemistry of uranium in the soil-plant and water-plant systems in an old uranium mine

“…The biogeochemical fate of uranium in polluted sites has been studied considering several aspects, such as the effect of microbial activity (e.g., Beazley et al, 2011;Hu et al, 2016), the plant-soil interaction (e.g., Tandy et al, 2013), the speciation, retention, mobility and bioavailability phenomena (e.g., Crawford and Liber, 2015;Du et al, 2016;Leermakers et al, 2016), the distribution in plants at the cellular level (e.g., Nie et al, 2015), the toxicity and biochemical responses in plants (e.g., Alves et al, 2009;Hogan et al, 2010;Horemans et al, 2016;Srivastava et al, 2010), the distribution in environmental compartments (e.g., Baumann et al, 2014;Kubrová et al, 2014;Pereira and Neves, 2012;Roivainen et al, 2011), the toxicity risk to biota, including humans (Caetano et al, 2014;Lottermoser, 2011;Pereira et al, 2014;Sheppard et al, 2005), and the prospects for U accumulation potential plant (e.g., Jha et al, 2016;Li et al, 2011;Pratas et al, 2014;Ramaswami et al, 2001).…”

Sampling root exudates – Mission impossible?

“…MSCs in combination with rhizoboxes of various designs allows spatially resolved (µl/mm) rhizosphere soil solution sampling at a known distance from a single root or root mat (Dessureault-Rompré et al, 2006;Oburger et al, 2013;Puschenreiter et al, 2005;Schulz and Vetterlein, 2007). An even higher spatial resolution was achieved by Tandy et al (2013) using glass micro-capillaries coupled with capillary electrophoresis/ ICP-MS to monitor the effect of organic acids on depleted uranium in the rhizosphere of white lupin on a nl/µm scale. Another technique that is gaining momentum is the use of microdialysis for sampling organic solutes within the rhizosphere.…”

New Methods To Unravel Rhizosphere Processes

“…However, they are not suited for the collection of unaltered root exudates or exudation rates because immediate interactions with the soil matrix (sorption) as well as microbial activity (the decomposition and release of microbial metabolites) will change compound composition. In a novel approach, microcapillaries coupled with capillary electrophoresis/inductively coupled plasma mass spectrometry (ICP-MS) were successfully used to monitor the effect of organic acids on depleted uranium in the rhizosphere of white lupin on a nl/mm scale (single-cell sampling and analysis, SiCSA) [22]. Recently, microdialysis has been introduced as a novel method to sample diffusive fluxes of metals [23,24] and nitrogen (N) species [25,26] from soil.…”