Carbon dioxide is the most important anthropogenic greenhouse gas having increased around 40% from the preindustrial period. Technological proposals including carbon capture and storage procedures, ...especially the mineral carbonation of CO2, have been evaluated to prevent or reduce carbon dioxide emission.
This research explores the possibility for CO2 sequestration on ceramic brick materials. A pilot-scale reaction chamber has been designed to mimic the carbonation process in an abandoned quarry. The filling materials are ceramic bricks and other construction with materials. The rubble is covered with common clay to seal the reaction sites.
Bricks are composed of quartz, diopside, wollastonite and orthoclase, and minor anhydrite. The common clay (marl) contains calcite, quartz, illite, smectite, and kaolinite. Room temperature reaction were conducted at 0.5 bar constant pressure, 4:1 solid/water. The reaction time was 5, 7, 9 and 12 months.
With the CO2 treatment, wollastonite, diopside, and anhydrite were practically destroyed at 12 months and calcite precipitated as a new phase in the bricks carbonation. With increased reaction time macro- and meso-porosity decreased. The micro- and nano-porosity increased due to closuere of bigger pores because of carbonate precipitation. Calcite increased in the common clay with reaction time near the top of the reaction vessel. It can be linked to the observed migration of moisture from the bricks to clay layers with the transport of carbonic acid and Ca ions for subsequent precipitation of calcite. The pilot investigation supports the proportion that brick waste can be used to sequester carbon.
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•Using ceramic bricks for the mineral carbonation as alternative of CCS technologies•Accelerated mineral carbonation under surface conditions in different reaction time•Common clay as sealing material•Partial destruction of calcium silicate, anhydrite and smectite•Emulation of quarry reclamation filled up with bricks and marl as sealing
This research explores the possibilities of CO2 sequestration on ceramic bricks in a short time and at surface conditions. The experiment was carried out in a specially designed reaction chamber, ...filled with brick wastes and sealed with common clays. The brick used were composed of quartz, wollastonite, diopside, orthoclase and anhydrite, and the common clay was a marl composed of calcite, quartz, illite, smectite and kaolinite. Experimental condition in the reaction chamber were: reaction time 5 months, pressure of CO2 0.5 bar, 4:1 solid/water ratio. The experiment was followed by XRD, XRF, BET, physical sorption by N2 and CO2, Hg porosity, TG-DTA, SEM and ICP-EOS.
After the CO2 treatment, wollastonite and anhydrite were practically destroyed and some diopside and orthoclase. Calcite precipitated as new phase (up to 48 wt%), and small amount of illite was the result of orthoclase alteration.
Concerning the sealing clay, the CO2 produced an increment of calcite content (from 32 to 41 wt%) and a partial destruction of smectite, particularly close to the upper part of the brick layer.
These results are hopeful in relation with the possible mineral carbonation of building ceramic waste in a short time at surface conditions, and open the opportunity to use those wastes for CO2 trapping in an appropriate system, as a quarry reclamation.
•Using ceramic brick for the mineral carbonation as alternative of CCS technologies•Accelerated mineral carbonation under surface conditions in a short time•Behaviour of a common clay as sealing material for CO2 capture•Partial destruction of calcium silicate, anhydrite and smectite•Emulation of quarry reclamation filled up with bricks and marl as sealing.
The aim of this work is to further the knowledge of reactions that can occur between carbon dioxide, diffused or escaped from a geological storage, and the sealing rock (e.g. clay-rich sediments). ...This research provides experimental data on the reactive behaviour of saponite (Mg-smectite), kaolin and Common Clay (composed of illite with minor montmorillonite) samples with CO2 in the presence of water or under dry conditions. The mechanisms for physical and chemical retention of CO2 were determined, and the influence of pressure, temperature and relative humidity on the effective sealing of the rock was examined. Firstly, the saponite did not physically adsorb CO2, and an amorphous phase was formed due to carbonic acid attack. Nevertheless, the Mg-smectite exchange cations, lead to the precipitation of dolomite and increase the mineral CO2 trapping. Secondly, the smectite and illite of the Common Clay sample were partially destroyed and the smectite destruction leads to the precipitation of some carbonates. Thirdly, kaolin did not physically trap CO2 nor any chemical reaction. This paper has demonstrated that the cannibalization of saponite and Common Clays is not total and the precipitation of carbonates may occur, which could avoid the progressive destruction of the sealing rock.
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•Evaluation of the behaviour of clays as sealing rocks in a CO2 geological storage•Mg-bentonite and montmorillonite–illite clays are susceptible to attacked by CO2.•Carbonate precipitation can partially prevent the clay destruction.•Proposed conceptual model helps to understand the role of clay in cap-rocks.
Risk assessment of soils polluted by potentially toxic trace elements generally is a complex procedure that includes many variables and parameters, many of them difficult to assess. The proposed ...methodological approach is an easier procedure to obtain reasonable security for the potential risk of a soil contaminated by trace elements. This approach can be successfully applied in most of the case studies, avoiding a sometimes flawed risk analysis procedure, which many times leads to an unnecessary declaration of soil pollution, resulting in mandatory and expensive reclamation actions.
The protocol supposes that: a) high concentrations of potentially toxic trace elements exceeding generic reference levels are not always a risk to human health, and b) the mobile fractions of potentially toxic trace elements and their bioavailability are the key factors to consider in any sort of risk assessment, when such assessments are needed.
The proposal consists of successive steps that ranges from a simple documentation and investigation of available information of the history, present state of the potential polluted site (PPS), mapping and field works to a detailed study that involves determination of local reference values, geoaccumulation factors, soil parameters, mobility, bioavailability, operational speciation, etc. For As, Hg, Cd, and Pb, particular procedures are also proposed.
As can be deduced from the proposal, anomalously high concentrations of potentially toxic trace elements in a soil, although they may exceed the generic reference levels, do not always pose a health risk. Thus, risk assessment is only necessary in a very few cases.
•Trace elements exceeding soil screening levels not always pose a health risk•Local baseline and bioavailable fraction should be key factors to consider for risk assessment.•The proposed protocol avoids undesirable errors derived from risk analysis methods.•The method allows assessing the potential risk without overestimating the pollution.
Abstract Background Most studies on the association between the frailty syndrome and adverse health outcomes in patients with heart failure (HF) have used non-standard definitions of frailty. This ...study examined the association of frailty, diagnosed by well-accepted criteria, with mortality, readmission and functional decline in very old ambulatory patients with HF. Methods Prospective study with 497 patients in six Spanish hospitals and followed up during one year. Mean (SD) age was 85.2 (7.3) years, and 79.3% had LVEF > 45%. Frailty was diagnosed as having ≥ 3 of the 5 Fried criteria. Readmission was defined as a new episode of hospitalisation lasting > 24 h, and functional decline as an incident limitation in any activity of daily living at the 1-year visit. Statistical analyses were performed with Cox and logistic regression, as appropriate, and adjusted for the main prognostic factors at baseline. Results At baseline, 57.5% of patients were frail. The adjusted hazard ratio (95% confidence interval) for mortality among frail versus non-frail patients was 1.93 (1.20–3.27). Mortality was higher among patients with low physical activity 1.64 (1.10–2.45) or exhaustion 1.83 (1.21–2.77). Frailty was linked to increased risk of readmission 1.66 (1.17–2.36) and functional decline odds ratio 1.67 (1.01–2.79). Slow gait speed was related to functional decline odds ratio 3.59 (1.75–7.34). A higher number of frailty criteria was associated with a higher risk of the three study outcomes (P trend < 0.01 in each outcome). Conclusions Frailty was associated with increased risk of 1-year mortality, hospital readmission and functional decline among older ambulatory patients with HF.
The trace element geochemistry of sepiolite-rich beds from five lithological sections in the Neogene Madrid Basin was analysed. The samples were collected from representative deposits including ...alluvial fan (Vicálvaro, Cabañas de la Sagra), palustrine (Cerro de los Batallones) and mudflat (Esquivias, Magán) facies. The mineralogical composition of the samples point out the abundant content of sepiolite, commonly higher than 95%, with variable content of quartz, feldspars, calcite, palygorskite and/or Mg-smectite. The sepiolite occurs as laminated, massive and brecciated facies, often with intraclasts of similar sepiolite composition. The geochemical results indicate that all the trace elements analysed are mostly depleted with respect to the UCC standard (Upper Crust Composition), especially REE (<0.4). The higher depletion was observed in sepiolites from mudflat facies (V and U content are an exception). Cluster analysis of geochemical data corroborates the differences between mudflat sepiolites and those from palustrine and alluvial-related facies. The normalization of REE with chondrite allows clear differentiation between the sepiolites associated with alluvial fan facies from all the remaining samples. On the other hand, the La/Sc ratio against Th/Co ratio indicates provenance from felsic rocks. High content in F (>4000μg/g) and low content of Li (20–180μg/g) is remarkable, allowing to separate samples of sepiolite formed in alluvial fan environments from those of mudflat and palustrine deposits. The geochemical complexity observed in the sepiolites was closely related to the specific mechanisms of formation under different environmental conditions.
•We analyse sepiolite from different sedimentary environments.•The geochemistry of sepiolite was controlled by the sedimentary environment.•The mechanism of sepiolite formation has geochemical fingerprint.
•Using ceramic bricks for the mineral carbonation as alternative of CCS technologies.•Accelerated mineral carbonation under surface conditions in a short time.•Partial destruction of calcium silicate ...and anhydrite and calcite precipitation.
This research explores the possibility of CO2 sequestration in ceramic building materials, namely, bricks. The bricks used are rich in calcium and magnesium. The reaction with CO2 was carried out in a sealed reactor with a 0.3 L volume in a CO2 atmosphere at a pressure of 10 bars. The solid-water ratio was 4:1, and the reaction time ranged from 24 h to 30 days. The results show that the carbonation was proportional to the reaction time. These results open new future possibilities of using brick waste to capture CO2 at ambient temperatures and low pressures.
A collection of 694 soil samples was taken from 367 sites (at a density of 1 site per 120 km2) in the western of Andalusia (SW Spain) to establish regional geochemical background of emerging critical ...elements on the < 2 mm soil fraction, and provide threshold values for anomaly detection to support mineral exploration in the survey area. The spatial distribution pattern of the soil geochemical anomalies is primarily influenced by the occurrence of magmatic alignments and metallogenic belts in the southern zones of the Iberian Massif. Soils over granitic parent materials are marked by W, Be, Ta and REE anomalies, whereas those derived from mafic igneous rocks contain anomalous concentrations of Sc, Co and V. Most of the threshold exceedances for Hf and Sb appear to be linked to soils on pelitic metasediments. The distribution of Sb and Co outliers is also related to sulfide ore occurrences in the bedrock and could be affected by anthropogenic influences. The Santa Olalla igneous complex, the granodioritic pluton of the Los Pedroches batholith and the magmatic alignment of Villaviciosa de Córdoba-La Coronada may represent exploration opportunities for high-tech elements, mainly for REE, although the identification of promising areas requires further investigation.
•Geochemical baselines of selected critical elements in soil were established.•Threshold values for mild and extreme anomaly detection were provided.•Bedrock lithology was inferred as the major source of soil geochemical anomalies.•Regional geology, parent rock and soil type influence the spatial distribution.
The analysis of environmental risk in historical cities facilitates the development of conservation strategies that can minimize the deterioration of historical heritage sites. Risk maps built with ...GIS software provide information about the probability of the main hazards in a region, and is a very useful tool to identify, evaluate and prioritize the restoration budget of a city in order to manage preventive conservation. In this paper, new methodologies are applied based on the vulnerability matrix and its relationship with static and structural factors, climate conditions, air quality and social agents. This technique has some obvious advantages in the application of risk analysis for cultural heritage conservation, such as the capability of simultaneous risk assessment and geographical references. The vulnerability study implies an on-site diagnosis analysis and requires an adapted protocol for archaeological heritage. The validation of this methodology was carried out in the historical town of Merida (Spain) with a GIS application (ArcGIS software), where the main monuments of this UNESCO World Heritage site were studied.
The ceramic properties of clay materials heated at high temperature are largely dependent on the mineral reactions, which usually are followed by XRD analysis on pressed pieces that are heated at ...different temperatures. Nevertheless, the use of “in-situ” high temperature X-ray diffraction (HTXRD) to follow the evolution of the crystalline phases under controlled temperature provides more precision. In this paper, the mineralogical changes produced during firing (RT-1000 °C) of two clay materials of very different mineralogical composition, frequently used in the manufacture of bricks in the SE Spain, have been studied by XRD classical procedure and with HTXRD, and the results obtained were compared. Although the phases identified by both X-ray analyses were the same, temperatures for the mineralogical reactions seem to be different, probably due to the experimental conditions. The patterns obtained by ex-situ XRD were at a higher speed than those by in-situ HTXRD, and probably the equilibrium was not achieved for the most reactions.
Because of the expansion of the mineral structure parameters occurred during heating the mineral reflections do not match with those found in the database JPCDS, neither the position nor intensities of some stable phases at high temperature. For the optimization of the interpretation of the HTXRD patterns, and to facilitate the kinetics of the new phases, it is necessary to work at a high integration time per step and a slow heating rate.
The in-situ HTXRD investigations of ceramic materials can save time respect to the classical XRD study of test-pieces heated at different temperatures, and lead immediate information of the transformation occurring on heating, which can be useful to improve the most suitable firing temperature in the industry.
•Ex-situ XRD and “in-situ” HTXRD of fired ceramic clay materials were compared.•Reaction kinetics at high temperatures is different.•Structural variations of high temperature phases can be observed by in-situ HTXRD.•The transformation temperature can be more accurately determined by in-situ HTXRD.
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