Impact of temperature on the dynamics of organic matter and on the soil-to-plant transfer of Cd,Zn and Pb in a contaminated agricultural soil

Predicting the soil-to-plant transfer of metals in the context of global warming has become a major issue for food safety. It requires a better understanding of how the temperature alters the bioavailability of metals in cultivated soils. This study focuses on one agricultural soil contaminated by Cd, Zn and Pb. DGT measurements were performed at 10, 20 and 30 °C to assess how the bioavailability of metals was affected by a rise in soil temperature. A lettuce crop was cultivated in the same conditions to determine if the soil-to-plant transfer of metals increased with a rise in soil temperature. A gradual decline in Cd and Zn bioavailability was observed from 10 to 30 °C, which was attributed to more intense complexation of metals in the pore water at higher temperatures. Together with its aromaticity, the affinity of dissolved organic matter (DOM) for metals was indeed suspected to increase with soil temperature. One main output of the present work is a model which satisfactorily explains the thermal-induced changes in the characteristics of DOM reported in Cornu et al. (Geoderma 162:65–70, 2011) by assuming that the mineralization of initial aliphatic compounds followed a first-order reaction, increased with soil temperature according to the Arrhenius law, and due to a priming effect, led to the appearance of aromatic molecules. The soil-to-plant transfer of Cd and Zn was promoted at higher soil temperatures despite a parallel decrease in Cd and Zn bioavailability. This suggests that plant processes affect the soil-to-plant transfer of Cd and Zn the most when the soil temperature rises.     

Elaboration of a Bio-Colored Material Based on Natural Dye and Polybutylene Succinate: Comparative Study with Colored Polylactic Acid

Journal of Polymers and the Environment - In the context of sustainable development and natural products valorization, new ecological materials enter a logic aimed at removing the causes of...     

Metal recovery in surface treatment units by using the 3PE reactor

Pollution from heavy metals arises mainly from industrial activities and, in this respect, it may be controlled and consequently reduced. The recovery of metals from industrial wastes is important, not only from an ecological point of view (toxicity), but also for economical reasons (recycling). At the present time, a large number of techniques are available to satisfy the stringent low concentration standards for waste water (Crine 1993; Verma et al. 1993). But for most of these techniques, it is not possible to have an immediate and total recycling of the recovered metal. With the development of the volumic electrodes, also called the flow-through porous electrodes, the electrochemical technique could be applied for the recovery of usable metals from effluents or dilute solutions and depollution. These electrodes are made up of a good conductor which has a porous structure through which the solution flows to be treated. In order to avoid disadvantages, such as the potential drop in the liquid phase and the problem of sealing, a new type of reactor called the Pulsating Porous Percolated Electrode (3PE) has been developed. This reactor eliminates the problem of plugging the particle bed by moving the matrix conductor during a fraction of time of the functioning of the reactor. This is done by using pulsed columns, which are largely used in different processes in chemical engineering. In this manner, one could expect to obtain the advantages of both the fixed and fluidized bed.