Search

Spent coffee grounds are a bio-residue studied as soil organic amendment and it has been proven that it has short-term effects on soil physical properties. However, its sequential effects on the cultivation of clayey soils are little studied. Therefore, an in vitro experiment was carried out to evaluate the effect of increasing doses (1%, 2%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15%) of spent coffee grounds on the physical properties of a clayey soil in the Spanish Mediterranean area which is rich in smectites. The addition of spent coffee grounds increased water retention at −33 and −1500 kPa proportionally to the added amounts, but the increase in the wilting point was much larger than the field water capacity, decreasing the plant available water content. A non-linear influence on the aggregate size is demonstrated. It increased total porosity and consequently reduced soil bulk density. This fact was reflected in the stereomicroscopy images where an increase in the pores analysed with image analysis was observed. Furthermore, SEM images corroborate that spent coffee grounds act intensely in the short-term due to the interaction between their particles and those of clay. The 5% dose acted as a threshold dose from which the greatest effects on soil physical properties occur. In general, the use of SCG as an organic amendment is a good sustainable solution because it supposes a reuse of this bio-residue (15 million tons per year), an increase in soil organic carbon (SCG contains ≈ 50% carbon) and an improvement of the soil physical and chemical properties., Andalusian Ministry of Economic Transformation, Knowledge Industry and Universities

Dust in the Earth´s atmosphere and deposition rates are both increasing in last decades. The south of Iberian Peninsula is deeply affected by air masses coming from Africa, one of the largest sources of atmospheric dust in the world (50%–70% of total emissions worldwide). Granada city (south of the Iberian Peninsula) has one of Spain’s highest atmospheric pollution levels (including particulate matter). African dust intrusion should be considered in the Iberian Peninsula because of the proximity of the Sahara Desert. Dust properties allows for a hypothesis on dust-provenance and dust-origin. Our study characterised atmospheric dust collected in Granada city during three monthly periods: 4PA (2012), 16PA (2013), and 28PA (2014). The main goal was to determine dust characteristics and genesis using a set of different techniques. The backward trajectories study separated the samples, according to their Saharan influence, into two groups: a) scarce influence (sample 16PA, 6% of days with Saharan influence); b) greater influence (samples 4PA and 28PA, ≈30% of days with Saharan influence). The two groups was confirmed by all the properties analysed, namely, PM10 concentration, deposition rates, grain size, mineralogy, and elemental composition (minor, including rare earth elements). Our samples showed similarities with soils from the Iberian Peninsula and other atmospheric dust collected in Granada. A remarkable discover was that particle morphology and surface microtextures on atmospheric quartz also verified the grouping. A principal component analysis of the quartz shape parameters insists on the differentiation of these groups, therefore we propose, as a fingerprint of provenance, the morphoscopy of atmospheric quartz grains (a main component of atmospheric dust).

This work was supported by a grant from Ministerio de Economia, Industria y Competitividad de Espana ("Mediterranean Soil Typologies versus Quartz. At the frontier of pedogenic knowledge"; Ref. CGL201680308-P). Funding for open access charge: Universidad de Granada/CBUA., Dust in the Earth́s atmosphere is increasing, particularly in southern Spain. The study of dust properties allows for a hypothesis on the origin and provenance of dust. This study characterised atmospheric dust deposited in the city of Granada (south of Spain) during three spring periods (samples 4PA, 16PA, and 28PA, collected in 2012, 2013, and 2014, respectively). The aim was to ascertain dust characteristics and genesis using a set of methodological techniques. The backward trajectories study separated the samples into two groups: scarce Saharan influence (sample 16PA, 6% of backward trajectories are from, or have passed through, Africa) and greater influence (samples 4PA and 28PA, 26% and 33%, respectively). This grouping was verified by the rest of the properties analysed, namely, PM10 concentration, deposition rates, grain size, mineralogy, and elemental composition (minor, including rare earth elements). In addition, mineral quartz showed differences in particle morphology and surface microtextures. The mineralogical and geochemical studies of our samples have proved similarities with other dust collected in Granada and soils from the Iberian Peninsula. The principal component analysis of the quartz shape parameters insists on the differentiation of these groups. We propose the morphoscopy of quartz grains (a significant component of atmospheric dust) as a fingerprint of provenance., Ministerio de Economia, Industria y Competitividad de Espana, Universidad de Granada/CBUA

Three peloids were studied, prepared with three mineral-medicinal water (MMW) from the spas at Alicun (sulphate, rich in magnesium and calcium, highly mineralized), Zujar (sulphate, rich in sodium chloride, highly mineralized) and Graena (sulphate, rich in magnesium and calcium, highly mineralized) (province of Granada, Spain) and matured for three months, in order to determine their properties and suitability for use in pelotherapy. Their solid phase was prepared by mixing kaolin and bentonite (9:1, w:w). In the peloids the following was studied: composition of interstitial liquid, granulometry, physicochemical properties (specific surface area -SSA-, cation exchange capacity -CEC- and exchangable bases), crystallinity index of the minerals, thermal behavior and ultramicroscopic fabric using scanning electron microscopy (SEM) and image analysis (IA). A modification of the ionic concentration of the interstitial liquid was observed with regard to the initial MMW, namely, an increase in the concentration of Na+ and K+, and a decrease in Ca2+ and Mg2+, due to exchange between the exchangable cations of the solid phase and the ions of the MMW. Increases in the proportion of fraction

Fourteen samples of deposited atmospheric dust collected during desert dust intrusions over Granada in the summer of 2010 are studied here. During these atmospheric dust events the PM10 ranged from 25 μg m−3 to 200 μg m−3, surpassing occasionally the standard limit (50 μg m−3) established by the European Union Directive as a risk for the human health. The mineralogical composition of the dust samples is very heterogeneous, showing that the origin of collected particles is from north-northwest of Africa and local/regional soils. The analyzed dust samples contain between 1 and 9% of iberulites, polymineral spherical particles with diameter between 34 and 111 μm. New compositional results obtained by mapping chemical elements and mineral compositions of iberulites with VPSEM-EDEX technology allowed as to go further than previous studies and provide new insight on the iberulites genesis. The SEM-microstructure analysis of the iberulites and the compositional results obtained by VPSEM-EDEX technique showed that clay and sulphur components are important in determining their spherical shapes. The analysis also shows that iberulites present a typical vortex at one of the poles and an external covering by nano-clays in laminar clusters, a form of rind and a core internal with sizes less than 10 μm. On the other hand, the micromorphological analysis evidences that the bacteria and its polymeric exudates participate in the iberulite genesis, acting as aggregation agents and contributing to its protection and compensating its fragility. The role of bacteria and its polymeric exudates in the iberulite genesis has not been described previously, and it would explain the flux, transport and survival of tropospheric microorganisms over long distances. These new observations and finding led us to take into account the role of bacteria in iberulite genesis and to reconsider the previous hypothesis regarding the iberulite genesis proposed in previous works.

Seven cosmetic-pharmaceutical talcum powders from different commercial brands, currently for sale in Spanish pharmacies, have been studied in order to determine their mineral and pharmacopoeia quality. Four samples met the required conditions to be classified both of “cosmetic quality” and “pharmacopoeia quality”. These conditions are: absence of potentially carcinogenic minerals, talc purity of more than 90%, low levels of toxic elements and suitable compositional levels of Al, Mg and Ca. The remaining three samples were classified as of “industrial quality”. Although these are free from fibrous minerals, the high carbonate content, specifically dolomite (close to 40%) and calcite (about 10%), impacts on the purity in talc by significantly reducing its quantity to the point that the material no longer satisfies many of the compositional tests of the European Pharmacopoeia. The detailed microanalysis with SEM-EDX and size measurements of elongated particles present in the samples showed them to be harmless as their mineral composition is talc and they appear in very low proportions. The SEM-EDX study highlighted the properties for which talcum powder has classically been employed for topical cutaneous use. The comparison of the current results with those of the Spanish market of talcum powder sold in pharmacies in the decade of the 1980s resulted in three principal findings. First, the fibrous minerals have disappeared. In the past, a significant number of samples showed evidence of amphiboles. Second, the purity in talc in samples of cosmetic quality has improved from 94% to 96%. Finally, in the 1980s there were no samples in the Spanish market with talc purity as low as today (60%). Dolomite is currently present in excessive quantities in some talcum powders.

Highlights Are lanthanides from fine sand and clay genetically related to the geological materials? Lanthanide concentrations of fine sand and clay fit chronofunctions Pearson's r of lanthanide couples decreases when separation increases in the periodic table Free forms of clay are scavengers of lanthanides and concentrate HREE and cerium, Sample preparation and chemical analysis were conducted by Emma Humphreys-Williams and Stanislav Strekopytov (Imaging and Analysis Centre, Natural History Museum, London, UK). This work was supported by a grant from Ministerio de Economía, Industria y Competitividad de España (‘Tipologías de Suelos Mediterráneos versus Cuarzo. En la frontera del conocimiento edafogenético’; Ref. CGL2016-80308-P). The authors thank Professor Margaret A. Oliver, an anonymous editor and two anonymous reviewers for helpful comments and suggestions that improved the final manuscript. We also thank Robert Abrahams (Bsc) for revising the English language., There is geochemical interest in the lanthanides because they behave like a group that is closely related to the parent materials during surface processes, although they also undergo fractionation as a result of supergene dynamics. We analysed lanthanide concentrations (ICPms) in the granulometric fractions fine sand, clay and free forms of clay (FFclay‐CDB and FFclay‐Ox: extracted with citrate‐dithionite‐sodium bicarbonate and with ammonium oxalate, respectively) from a soil chronosequence of Mediterranean soils. There was a relative enrichment of heavy rare earth elements (HREE) in the clay fraction and its free forms with respect to fine sand. The clay free forms behaved as scavengers of lanthanides, and oxidative scavenging of cerium (Ce) in FFclay‐CDB was also detected. Lanthanide concentrations (lanthanum to gadolinium in fine sand; terbium to lutetium in clay) varied with soil age, and chronofunctions were established. There was a strong positive collinearity between most of the lanthanide concentrations. Furthermore, the value of the correlation index (Pearson's r ) of the concentrations between couples of lanthanides (r CLC) decreased significantly with increasing separation between the elements in the periodic table; this has never been described in soils. Several geochemical properties and indices in the fine sand and clay soil fractions and in the geological materials of the Guadalquivir catchment showed, on the one hand, a genetic relation between them all, enabling the lanthanides to be used as fingerprints of provenance; on the other hand, fractionation between fine sand and clay showed these are actively involved in soil lanthanide dynamics., Secretaría de Estado de Investigación, Desarrollo e Innovación. Grant Number: CGL2016‐80308‐P