Experimental investigation of multiple industrial wastes for carbon dioxide removal strategies

Industrial solid waste by-products are being increasingly employed for geochemical carbon dioxide removal (CDR) strategies due to their fine grain size, accessibility, and large annual production tonnages. Here, a range of such by-products has been tested experimentally for their reactivities with CO2 and water. Sample solutions were monitored for 100 h for changes in chemistry, and solid samples were characterised pre- and post-experiment. Samples rich in Ca- and Mg-bearing minerals, such as dunite, kimberlite, and ilmenite mine tailings, as well as marble quarry cuttings, were key cation sources. Ni sulphide, fluorite and borax tailings, coal-fired power plant fly ashes, and red mud samples showed high dissolution rates. The highest reaction rates were often observed during the initial few hours, and compared well to rates determined for rocks typically targeted for CDR purposes, such as basalt and gabbro. Several samples also showed secondary carbonate precipitation, suggesting opportunities for the development of single-step CDR technologies. Overall, the results of this study indicate that several industrial by-products can provide sufficient cations at favourable dissolution rates for geochemical CDR purposes. Any on-site or near-site conditions for reaction acceleration such as heat, concentrated CO2 or microbes, could further increase favourability for geochemical CDR opportunities.LB and JLFT are funded under H2020-EU.1.3.2. (DETAILS Project, grant agreement ID: 101018312)

Mineralogía del Prospecto Bajo Agua Tapada, Catamarca, Argentina

El objeto de este trabajo es la definición por vez primera de las asociaciones minerales (menas productivas y paragénesis de alteración hidrotermal)del llamado Prospecto Bajo Agua Tapada, de cara a la realización de una primera valoración de su interés; este trabajo se ha realizado tanto mediante mapeo y muestreo superficial como tras el estudio (mineralógico y geoquímica)de unos 2800 m de sondeos realizados a testigo contínuo

Volcanic ash leaching as a means of tracing the environmental impact of the 2011 Grímsvötn eruption, Iceland

The Grímsvötn volcanic eruption, from 21 to 28 May, 2011, was the largest eruption of the Grímsvötn Volcanic System since 1873, with a Volcanic Explosivity Index (VEI) of magnitude 4. The main geochemical features of the potential environmental impact of the volcanic ash-water interaction were determined using two different leaching methods as proxies (batch and vertical flow-through column experiments). Ash consists of glass with minor amounts of plagioclase, clinopyroxene, diopside, olivine and iron sulphide; this latter mineral phase is very rare in juvenile ash. Ash grain morphology and size reflect the intense interaction of magma and water during eruption. Batch and column leaching tests in deionised water indicate that Na, K, Ca, Mg, Si, Cl, S and F had the highest potential geochemical fluxes to the environment. Release of various elements from volcanic ash took place immediately through dissolution of soluble salts from the ash surface. Element solubilities of Grímsvötn ash regarding bulk ash composition were <1 %. Combining the element solubilities and the total estimated mass of tephra (7.29 × 1014 g), the total inputs of environmentally important elements were estimated to be 8.91 × 109 g Ca, 7.02 × 109 g S, 1.10 × 109 g Cl, 9.91 × 108 g Mg, 9.91 × 108 g Fe and 1.45 × 108 g P The potential environmental problems were mainly associated with the release of F (5.19 × 109 g)

Mecanismos eruptivos del volcán Puig de la Garrinada (Olot, provincia volcánica de La Garrotxa, NE España): estudio metodológico desarrollado en depósitos piroclásticos proximales

Se ha estudiado un afloramiento efímero en la base de un cono basáltico monogénico en la región volcánica de La Garrotxa para estudiar variaciones en los mecanismos eruptivos en el curso de una erupción. Una vez establecida la vulcanoestratigrafía se realizó un muestreo muy detallado (incluyendo coladas de lava basales, bombas y gran número de capas de ceniza y lapilli). Se desarrolló una ficha de descripción para el estudio con lupa binocular de los materiales piroclásticos finos y su distribución en la serie. Seguidamente se hicieron estudios morfoscópicos con SEM+EDS y caracterización geoquímica básica (mayores y trazas) de las muestras con FRX. Con todo esto se ha reconstruido la historia eruptiva, mostrando una transición desde una actividad inicial estromboliana a una freatomagmática; esto permitió inferir variación en la tasa de flujo magmático, oscilaciones de la columna de magma, e interacciones con el acuífero. Dado el buen acuerdo entre las conclusiones generales y la diferenciación de las fases eruptivas a partir de los datos de la ficha descriptiva, vulcanoestratigrafía macroscópica, y geoquímica, se propone que un protocolo de estudio como este (y el muestreo asociado) puede ser útil en la reconstrucción de la actividad eruptiva de conos piroclásticos similares

The Holocene volcanism of Gran Canaria (Canary Islands, Spain)

This work presents the first detailed map of the Holocene eruptions of Gran Canaria (Canary Islands, Spain). It provides complete and detailed information for all 24 Holocene eruptions of Gran Canaria, improving the knowledge of this recent volcanism and the assessment of volcanic hazards on the island. This map is a synthesis of collated and interpreted field data and topographic maps. We have integrated information obtained from: (1) detailed geological field surveys, (2) morphometric analysis of eruptive deposits, (3) high-resolution digital elevation models, and (4) aerial photographs

Using Chemical Modeling to Asses Water Quality in the Raigón Aquifer System in Southern Uruguay

The Raigón aquifer is an important groundwater system in southern Uruguay. The increasing use of groundwater resources in the last decades has provoked changes in the concentration of many elements which are strongly related to anthropogenic pollution sources. Concentration levels are useful to detect changes in reservoir status but it is also necessary to analyze their chemical significance in order to make an accurate assessment of the sources of contamination and the causes of changes. In this work we use the available thermodynamic data to calculate chemical speciation on these groundwater samples. Trace elements present as anions, in particular Se and Mo, are especially focused to show the chemical modeling possibilities. Both elements form anionic species, predominantly MoO42- and SeO42-. Results show that these anions interact in solution and are greatly influenced by the concentration of the abundant calcium ion. Localized changes in pH can strongly affect the situation. The same is observed with the pE parameter, but only in the case of Se. Chemical speciation of trace elements is in general highly dependent on pH, pE and concentration of major elements. In consequence, for a fixed analytical total concentration, these parameters can markedly change the situation, affecting the mobility, the bioavailability and environmental fate of these elements. The strategy employed in this work can also be extended to the study of many other environmental water scenarios

The Holocene volcanism at El Hierro: insights from petrology and geochemistry

The Holocene volcanism at El Hierro consists of basaltic monogenetic volcanic fields associated with o the three rift systems present in this island. In this work we report preliminary petrological and geochemical data of Holocene lava flows belonging to the WNW-striking rift. Sampling was focused in three zones: Orchilla, Verodal-Sabinosa, and Tanganasoga. Petrography of the studied lavas shows that they are homogeneous. All samples are porphyritic with macrocrysts of clinopyroxene and olivine immersed in a groundmass formed by microcrysts of plagioclase, Fe-Ti oxides and clinopyroxene. Clinopyroxenes are diopsides, olivines have forsterite contents ranging from 74 to 84 % and anorthite in plagioclase varies from 66 to 76% (labradorite). Whole-rock geochemical results evidence that all magmas are basic in composition, ranging from picrobasalts to phonotephrites. Major, trace elements and isotope suppor fractional crystallization as the main process of magma evolution. However, petrography and chemistry of clinopyroxene cores agree with a xenocrystic nature of some of them. We suggest that these clinopyroxene cores crystallized from a genetically related magma and subsequently were entrapped o cannibalized by the basic rising magmas

Origin of green clinopyroxene cores of lavas from the garrotxa volcanic field (spain)

Volcanism of the Garrotxa area is part of the Neogene volcanism of NE Spain (NE Spain volcanic province, NESVP). This volcanism is a manifestation of the magmatic activity consequence of the rift-type extensional tectonics that affect the eastern margin of Iberia since late Oligocene and that involved the opening of the Valencia trough. Volcanic activity in the NESVP started weakly in the Cadaqués zone 15 Ma ago, (C. Lewis, personal communication), followed by the Empordà (9 to 12 Ma in Alt Empordà, 6 Ma in Baix Empordà), La Selva field (5 to 7 Ma) and the Tordera fault system (2 Ma). Finally, activity took place at the Garrotxa volcanic field (GVF) from 300,000 to 10,000 years ago, with an eruptive episode every 15,000 to 20,000 years approximately (C. Lewis personal communication)