Unraveling a hydrous alkaline metasomatic agent beneath the Styrian Basin: an inclusion study from mantle xenolith

Aradi L. et al. (2019) ECROFI2019 konferencián bemutatott absztraktj

Amphibole-hosted fluid inclusion in mantle xenolith from the Eastern Transylvanian Basin

Szabó Ábel et al. 2019 ECROFI2019 absztrakt kötetben megjelent absztraktj

Effectiveness and Characterization of Novel Mineral Clay in Cd2+ Adsorption Process: Linear and Non-Linear Isotherm Regression Analysis

The excellent adsorption properties of clay minerals make the optimization of heavy metal removal the subject of numerous research projects. In the present study, ASLAVITAL cosmetic clay (ACC) powder was applied for the removal of Cd2+ from water. The main deposit of ACC clay is the Pădurea Craiului Mountains in Romania. A wide range of morpho-structural approaches (SEM, EDX, FTIR, Raman, XRD) were used to characterize the morphology and elemental composition of the adsorbent. As expected for clay minerals, Al (Wt(%) = 11.4 ± 0.9) and Si (Wt(%) = 13.7 ± 1.4) are the main constituents of ACC. After adsorption, Wt(%) = 0.2 ± 0.01 Cd2+ was detected in the sample. As proved before, the initial metal concentration is the primary influencing factor; therefore, batch adsorption of 10–160 mg/L Cd2+ was investigated. After 190 min, an efficiency of 99% was reached, and the quantity in equilibrium increased from 1–8 mg/g. The best fit in linear form was obtained for the Langmuir II. model, where R2 = 0.954 (RL = 0.037–0.027). Based on linear isotherm models, physical bonds formed between ACC and Cd2+ during the favorable adsorption. For the non-linear fits, the Liu model proved to be the best R2 = 0.965, χ2 = 1.101. Pseudo-II-order kinetic model described the experimental data R2 = 0.988–0.999; qexp and qcalc were almost identical (the differences ranged 0.03–0.34)

Signs of in-situ geochemical interactions at the granite–concrete interface of a radioactive waste disposal

Abstract Eleven unique core samples from the National Radioactive Waste Repository of Hungary, Bátaapáti were studied in this work. The samples all cross the granite–concrete interface and have been drilled from around 275 m depth from the surface, 1–15 months after concrete injection. Phase analytical techniques, optical microscopy, SEM-EDS and Raman-spectroscopy were used for the analysis of interactions between granitic rock and cementitious building material. Newly formed phases, Ca-carbonates and titanite, were observed at the interface. Carbonation may reduce the porosity and permeability in the contact zone. The presence of titanite indicates the changing geochemical and thermodynamical constrains along the reaction front of granite–concrete, furthermore, it may help in the validation of future geochemical models. The cementitious material is seen to penetrate among the sheets of biotite mineral in granite which process is probable to cause the attachment of granite and concrete

Iron isotope and trace metal variations during mantle metasomatism: In situ study on sulfide minerals from peridotite xenoliths from Nógrád-Gömör Volcanic Field (Northern Pannonian Basin)

Sulfides from lherzolite and wehrlite xenoliths from the Nógrád-Gömör Volcanic Field (NGVF), located in the Northern Pannonian Basin, were studied to understand the behavior of chalcophile and siderophile elements during mafic melt – peridotite interaction. We applied in situ methods to analyze the major and trace elements, as well as Fe isotope compositions of sulfide minerals. Sulfides are more abundant in wehrlites (~0.03 vol%) and are often enclosed in silicates, whereas in lherzolites, they are scarcer (~0.01 vol%) and predominantly interstitial. Monosulfide solid solution and pentlandite are the most common sulfide phases in the lherzolite xenoliths, whereas in wehrlite xenoliths it is pyrrhotite and chalcopyrite. Consequently, wehrlitic sulfides show higher bulk Fe and Cu but lower bulk Ni and Co contents compared to the lherzolitic sulfides. Trace elements with both chalcophile and siderophile character (Ge, Se, Te, and Re) show lower, whereas highly chalcophile elements (Zn, Cd, Sb, and Tl) show higher concentrations in wehrlitic sulfides compared to lherzolitic ones. Highly siderophile elements show no systematic difference between the sulfides of the two xenolith series, which suggests moderate enrichment in these elements in wehrlite bulk rocks due to their higher sulfide content. Sulfide δ56Fe signature indicates variable isotopic composition both in lherzolites (δ56Fe: −0.13 to +0.56‰) and wehrlites (δ56Fe: −0.20 to +0.84‰) relative to the terrestrial mantle (δ56Fe: +0.025 ± 0.025‰; Craddock et al., 2013). However, irrespectively of the xenolith lithology, there is a significant difference between the δ56Fe of sulfides from the two sampling localities: NTB /North/: vary from −0.20 to +0.04‰ and NME /South/: vary from +0.56 to +0.84‰. This suggests that the Fe isotopic ratios of sulfides are not modified by the wehrlitization process. Difference in sulfide δ56Fe between the two xenolith localities is probably because of the higher, isotopically heavier (δ56Fe: from +1.28 to +1.60‰; Ciążela et al., 2019) chalcopyrite content in sulfides from the NME xenoliths compared to those from the NTB xenoliths irrespectively to their lithology. Our results also indicate sulfide and chalcophile element enrichment resulting from metasomatism in the subcontinental lithospheric mantle. We suggest that this process affected the regional metal distribution and has implications for global metal mass balance within the subcontinental lithosphere