Influence of non-equilibrium and nonlinear sorption of Cs in soils. Study with stirred flow-through reactor experiments and quantification with a nonlinear equilibrium-kinetic model.

This paper addresses the modelling of cesium sorption in non-equilibrium and nonlinear conditions with a two-site model. Compared to the classical K approach, the proposed model better reproduced the breakthrough curves observed during continuous-flow stirred tank reactor experiments conducted on two contrasted soils. Fitted parameters suggested contrasted conditions of cesium sorption between 1) equilibrium sites, with low affinity and high sorption capacity comparable to CEC and 2) non-equilibrium sites, with a fast sorption rate (half-time of 0.

Efficiency of dihydroxamic and trihydroxamic siderochelates to extract uranium and plutonium from contaminated soils.

Actinide-based mineral phases occurring in contaminated soils can be solubilized by organic chelators excreted by plants, such as citrate. Herein, the efficiency of citrate towards U and Pu extraction is compared to that of siderophores, whose primary function is the acquisition of iron(III) as an essential nutrient and growth factor for many soil microorganisms. To that end, we selected desferrioxamine B (DFB) as an emblematic bacterial trishydroxamic siderophore and a synthetic analog, abbreviated (L)H, of the tetradentate rhodotorulic acid (RA) produced by yeasts.

Uranium transfer and accumulation in organs of Danio rerio after waterborne exposure alone or combined with diet-borne exposure.

Uranium (U) toxicity patterns for fish have been mainly determined under laboratory-controlled waterborne exposure conditions. Because fish can take up metals from water and diet under in situ exposure conditions, a waterborne U exposure experiment (20 μg L , 20 d) was conducted in the laboratory to investigate transfer efficiency and target organ distribution in zebrafish Danio rerio compared with combined waterborne exposure (20 μg L ) and diet-borne exposure (10.7 μg g ).

Influence of root exudation of white lupine (Lupinus albus L.) on uranium phytoavailability in a naturally uranium-rich soil.

Mechanisms of uranium (U) transfer from soil to plants remain poorly understood. The kinetics of supply of U to the soil solution from solid phases could be a key point to understand its phytoavailability and implications for environmental risk assessment. Root activity, particularly the continuous release of organic acids in the rhizosphere, could have an effect on this supply.

Do rhizospheric processes linked to P nutrition participate in U absorption by Lupinus albus grown in hydroponics?

Phosphate (P) is an essential element for plant development but is generally present in limiting amount in the soil solution. Plant species have developed different mechanisms promoting the solubilization of this element in soils to ensure a sufficient supply for their growth. One of these mechanisms is based on the ability of certain species such as L.