An evaluation of the feasibility of electrostatic separation for physical soil washing

[EN] We present the first application of electrostatic separation for soil washing. Soil samples were collected from the PTE-containing area of La Cruz in Linares, southern Spain. Using a single-phase high-tension roll separator with voltages ranging from 20 kV to 41.5 kV, we achieved yield values between 0.69% and 9%, with high recovery rates for certain elements such as Zn, Cu, and Mo. SEM-EDX analysis revealed three particle types, including a non-conductive fraction composed of feldspar, a middling fraction composed of mica, and a conductive fraction consisting of PTE-bearing slag grains. Attributive analysis showed that 41.5 kV was the optimal voltage for maximizing PTE concentration. Overall, electrostatic separation is a promising approach for treating soils contaminated with PTEs, particularly in dry climate areas impacted by mining activities.S

Molecular characterisation of virulence graded field isolates of myxoma virus

<p>Abstract</p> <p>Background</p> <p><it>Myxoma virus </it>(MV) has been endemic in Europe since shortly after its deliberate release in France in 1952. While the emergence of more resistant hosts and more transmissible and attenuated virus is well documented, there have been relatively few studies focused on the sequence changes incurred by the virus as it has adapted to its new host. In order to identify regions of variability within the MV genome to be used for phylogenetic studies and to try to investigate causes of MV strain attenuation we have molecularly characterised nine strains of MV isolated in Spain between the years 1992 and 1995 from wide ranging geographic locations and which had been previously graded for virulence by experimental infection of rabbits.</p> <p>Results</p> <p>The findings reported here show the analysis of 16 genomic regions accounting for approximately 10% of the viral genomes. Of the 20 genes analysed 5 (M034L, M069L, M071L, M130R and M135R) were identical in all strains and 1 (M122R) contained only a single point mutation in an individual strain. Four genes (M002L/R, M009L, M036L and M017L) showed insertions or deletions that led to disruption of the ORFs.</p> <p>Conclusions</p> <p>The findings presented here provide valuable tools for strain differentiation and phylogenetic studies of MV isolates and some clues as to the reasons for virus attenuation in the field.</p

Assessment of co-contaminated soil amended by graphene oxide: Effects on pollutants, microbial communities and soil health

Graphene oxide (GOx) is a nanomaterial with demonstrated capacity to remove metals from water. However, its effects on organic pollutants and metal(loid)s present in polluted soils when used for remediation purposes have not been extensively addressed. Likewise, few studies describe the effects of GOx on edaphic properties and soil biology. In this context, here we assessed the potential of GOx for remediating polluted soil focusing also on different unexplored effects of GOx in soil. To achieve this, we treated soil contaminated with concurrent inorganic (As and metals) and organic pollution (TPH and PAHs), using GOx alone and in combination with nutrients (N and P sources). In both cases increased availability of As and Zn was observed after 90 days, whereas Cu and Hg availability was reduced and the availability of Pb and the concentration of organic pollutants were not significantly affected. The application of GOx on the soil induced a significant and rapid change (within 1 week) in microbial populations, leading to a transient reduction in biodiversity, consistent with the alteration of several soil properties. Concurrently, the combination with nutrients exhibited a distinct behaviour, manifesting a more pronounced and persistent shift in microbial populations without a decrease in biodiversity. On the basis of these findings, GOx emerges as a versatile amendment for soil remediation approaches

A multivariate examination of the timing and accumulation of potentially toxic elements at Las Conchas bog (NW Spain)

The inorganic content of the well-preserved 3.2-m record of Las Conchas bog (NW Spain), covering 8000 cal yr BP., was analysed. To study natural vs. human contributions, we applied an innovative approach, namely the sequential study of multivariate statistics (factor analysis followed by clustering of the factor score matrix) and enrichment factors (EFs). The increasing weight of potentially toxic elements (PTEs) such as the geochemical association of Zn, Pb and Cd (EFs higher than 10, 20 and 40 in the last two centuries) was revealed, and corroborated by the contrast between the contents of anthropogenic Pb and total Rare Earth Elements (a suitable proxy for natural geogenic supplies). Furthermore, elements such as Hg, Tl and As also showed enrichment in the most recent samples of the study core. Some of them are commonly associated with global atmospheric transport; however, in this case, their increasing contents could also be explained by nearby industrial and mining activities. In summary, severe pollution was observed in the uppermost part of the record, thereby pointing to an important environmental concern. Given that local and regional sources of PTEs, such as mining and heavy industry, especially Zn smelting, were probably the main historical causes of this contamination and that some of these industries are still active, we consider that our findings deserve further attention.This paper was funded by the Spanish Commission of Science and Technology (CICYT), projects CGL2013-46458-C1-1-R and CGL2013-46458-C2-2-R

Antagonistic Cd and Zn isotope behavior in the extracted soil fractions from industrial areas

The remobilization of metals accumulated in contaminated soils poses a threat to humans and ecosystems in general. Tracing metal fractionation provides valuable information for understanding the remobilization processes in smelting areas. Based on the difference between the isotopic system of Cd and Zn, this work aimed to couple isotope data and their leachability to identify possible remobilization processes in several soil types and land uses. For soil samples, the delta Zn-66/64 values ranged from 0.12 +/- 0.05 parts per thousand to 0.28 +/- 0.05 parts per thousand in Avil & eacute;s (Spain) and from - 0.09 +/- 0.05 parts per thousand to - 0.21 +/- 0.05 parts per thousand in Pr & iacute;bram (Czech Republic), and the delta Cd-114/110 ranged from - 0.13 +/- 0.05 parts per thousand to 0.01 +/- 0.04 parts per thousand in Avil & eacute;s and from - 0.86 +/- 0.27 parts per thousand to - 0.24 +/- 0.05 parts per thousand in Pr & iacute;bram. The metal fractions extracted using chemical extractions were always enriched in heavier Cd isotopes whilst Zn isotope systematics exhibited light or heavy enrichment according to the soil type and land uses. Coupling Zn and Cd systematics provided a tool for deciphering the mechanisms behind the remobilization processes: leaching of the anthropogenic materials and/or metal redistribution within the soil components prior to remobilization

Remediación de suelos contaminados con arsénico, selenio y metales mediante espumas de carbono impregnadas con nanopartículas de goetita

Los autores agradecen la financiación recibida a través de los proyectos de investigación MCI-20-PID2019-106939GB-I00 (AEI/España, FEDER/UE), PID2020-113558RB-C43 (MCIN/ AEI/10.13039/501100011033) e IDI/2021/000031. Diego Baragaño agradece la ayuda Postdoctoral obtenida (Ref. MU-21-UP2021-030 32892642) de la Universidad de Oviedo