Papers by Francesco Cavalcante
Journal of Cleaner Production, Aug 1, 2023
Powder Technology, Oct 1, 2017
Sodalite, faujasite and A-type zeolite from 2:1dioctahedral and 2:1:1 trioctahedral clay minerals... more Sodalite, faujasite and A-type zeolite from 2:1dioctahedral and 2:1:1 trioctahedral clay minerals. A singular review of synthesis methods through laboratory trials at a low incubation temperature
Waste Management, May 1, 2010
In this study Italian coal fly ash was converted into several types of zeolite in laboratory expe... more In this study Italian coal fly ash was converted into several types of zeolite in laboratory experiments with temperatures of crystallization ranging from 35 up to 90 degrees C. Distilled and seawater were used during the hydrothermal synthesis process in separate experiments, after a pre-treatment fusion with NaOH. The results indicate that zeolites could be formed from different kind of Italian coal fly ash at low temperature of crystallization using both distilled and seawater. SEM data and the powder patterns of X-ray diffraction analysis show that faujasite, zeolite ZK-5 and sodalite were synthesized when using both distilled and seawater; zeolite A crystallized only using distilled water. In particular the experiments indicate that the synthesis of zeolite X and zeolite ZK-5 takes place at lower temperatures when using seawater (35 and 45 degrees C, respectively). The formation of sodalite is always competitive with zeolite X which shows a metastable behaviour at higher temperatures (70-90 degrees C). The chemical composition of the fly ash source could be responsible of the differences on the starting time of synthesized zeolite with distilled water, in any case our data show that the formation of specific zeolites takes place always at lower temperatures when using seawater.
Molecules, Aug 23, 2018
Time-stability of LTA zeolite formed by hydrothermal method with or without the action of ultraso... more Time-stability of LTA zeolite formed by hydrothermal method with or without the action of ultrasonic irradiation was investigated by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The results show that 6 months after the synthesis by hydrothermal process with continuous sonication, LTA evolves into a more stable sodalite, whereas no differences are detected 12 months after LTA synthesis by conventional pre-fused hydrothermal process. These data confirm that using the two approaches, different mechanisms control both zeolite crystallization and time-stability of the newly-formed mineral at solid state. The results are particularly important in the light of the synthetic zeolite application.
The paper compares the potential of WorldView-3 (WV-3) and Sentinel-2 (S-2) satellite data for ma... more The paper compares the potential of WorldView-3 (WV-3) and Sentinel-2 (S-2) satellite data for mapping naturally occurring asbestos (NOA) outcrops to be used by geologists in the planning phase of environmental monitoring. The wide distribution as well as the variety and extent of asbestos-bearing rocks make the selected area a significant case study for the evaluation of the feasibility of multispectral VNIR-SWIR (0.425-2.330 µm) remote sensing observations for NOA outcrops mapping, in those areas where the density of vegetation allows their spectral identification. Different classification procedures were used to produce NOA outcrops maps for the study area. In our study, we found in general a good agreement (k > 0.8) between the produced NOA outcrops maps and the extensive available in situ data for the accessible locations.
Journal of Cluster Science
Geomatics, Natural Hazards and Risk
The accurate characterization of microearthquake sequences allows seismologists to shed light on ... more The accurate characterization of microearthquake sequences allows seismologists to shed light on the physical processes involved in earthquake nucleation, the deformation processes underlying rupture activation and propagation, and to image faults geometry at depth. The current methodologies used for this purpose first need the event detection and the phase-picking - usually manual-based - and earthquake locations, which require plenty of work even by expert analysts particularly in the case of microearthquake signals, commonly noise contaminated. Thus, improving standard procedures through semi-automatic or fully-automatic workflows would be an essential step forward towards the more efficient analysis of seismic sequences.Here we show the results of a semi-automated template matching and machine-learning based workflow applied for the characterization of the foreshock-mainshock-aftershock microearthquake sequence occurred close to Castelsaraceno village (High Agri Valley, Southern...
Geological Magazine, May 19, 2022
Highlights-Open-to-tidal lagoonal depositional settings assessed for the study carbonates, which ... more Highlights-Open-to-tidal lagoonal depositional settings assessed for the study carbonates, which were then subjected to a 4-5 km tectonic load.-Depositional and diagenetic primary architecture affected both failure modes and fracture distribution in the carbonate multilayer.-Fracture compartmentalization within coarse grained carbonate beds due to both physical and chemical compaction and cementation processes.-Main failure modes associated to specific structural assemblages related burial diagenesis, early thrusting, thrusting, and transtentional faulting.
Journal of Environmental Chemical Engineering, 2022
Landslides, 2020
Landslides represent a major geomorphological feature influencing the evolution of the southern A... more Landslides represent a major geomorphological feature influencing the evolution of the southern Apennine slopes with earth flows being one of the most representative types of landslide. The development of earth flows in the southern Apennines is facilitated by the widespread occurrence of clayey lithologies. Earth flows can either produce marked scars along the slopes, when their activity is high, or give rise to bumpy areas that are frequently covered by vegetation, when their activity is low. In this latter case, although the risk is significantly reduced, the earth flow can still represent a problem for buildings and infrastructure. The Picerno earth flow in the Basilicata region is an example of a lowactivity earth flow. This NW-SE-oriented landslide extends for a length of~5.5 km, has an average width of~680 m, and affects the village of Picerno. Our investigations mainly focused on the terminal portion of the landslide and revealed that some significant linear infrastructures (e.g., the Potenza-Naples railway) and important provincial and municipal roads are affected by the earth flow. In order to better define the amount of displacement characterizing the Picerno earth flow and gain insights into the lateral extension and the depth of the main detachment surface, we undertook a detailed geological and geomorphological survey. Interferometry synthetic aperture radar data provided by the processing of SAR images, with the aim of highlighting the regions of the landslide that are currently active, together with electrical resistivity tomography data which have been utilized to define the geometry of the landslide body. Our results provide useful suggestions for planning appropriate actions aimed at stabilizing the landslide body.
Landslide inventory map of the drainage basin of the Fiumarella di Corleto (Southern Apennines, I... more Landslide inventory map of the drainage basin of the Fiumarella di Corleto (Southern Apennines, Italy). The map shows the processes and landforms recognised in the study area and in particular the numerous landslides generated by the complex interaction between structural, gravitational and fluvial processes. The acquired data relate to a geologically complex area of the southern Apennines subject to recent uplift and represent a fundamental contribution useful for the correct management of the territory.
Microporous and Mesoporous Materials, 2021
Abstract Mt. Etna, the largest volcano in Europe, is periodically interested by intensive eruptio... more Abstract Mt. Etna, the largest volcano in Europe, is periodically interested by intensive eruption activity sometimes causing environmental problems for the neighbouring urban areas such as Catania. The volcanic ash deposited on the roads is classified as waste (code 20 03 03 – municipal waste from European Waste Catalogue - EWC). In this work, with the aim to transform waste materials into useful product, two samples of ashes resulting from different explosive activities were treated by hydrothermal aging with distilled water and seawater. The results showed that the hydrothermal process determined mineralogical and magnetic changes in volcanic ashes. The data in fact indicated that X-type zeolite and sodalite were formed at 45, 60 and 70 °C of aging temperature. Moreover, magnetic characterization suggests an evolution of ferromagnetic materials to antiferromagnetic ones during zeolite formation. The presence of these new magnetic phases was responsible for the variety of magnetic behaviour. The applicability of obtained zeolite as novel adsorbent material in the field of water treatment was also evaluated. Batch adsorption experiments were carried to assert the adsorption capacity of novel synthetized zeolite in removing cesium ions from aqueous solutions thus confirming a possible End-of-Waste alternative.
Microporous and Mesoporous Materials, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Geoheritage, 2019
Since prehistoric times stones have been widely employed in the construction of historic building... more Since prehistoric times stones have been widely employed in the construction of historic buildings, floors, and claddings in rural and urban areas. Among the Italian natural stones, the sandstone belonging to the Gorgoglione Formation, known as the Gorgoglione Stone, quarried and worked near the homonymous village in Basilicata (Southern Italy), is usually used as a building material. The Gorgoglione Stone consists of well-cemented turbidite sandstones deposited in a Middle-Upper Miocene thrust-top basin unconformably resting on the external nappes of the Southern Apennine thrust belt. In the Gorgoglione area, it can be observed in either numerous natural outcrops or quarries. This study aims to highlight the geological peculiarities of the Gorgoglione Stone and, in particular, it is focused on its mechanical characterization for assessing the most effective use when employed in construction, such as public and civil buildings, road construction, paving, and small works of art. Based on the experimental results, obtained by samples collected from different quarries, axial stress-strain curves have been plotted, whose analysis has delivered the deformation behavior and the strength characteristics of the stone. The elastic modulus, uniaxial compressive strength, and axial strain at stress peak have been estimated for several specimens. The measured values are typically of a medium-high-strength sandstone. The tested specimens of sandstone exhibit a typical behavior of an elastic-brittle rock, characterized by a linear path and a failure typically of axial splitting. With regard to the results of the physical tests, they showed that the analyzed sandstone is characterized by quite low density and by medium-high porosity and water absorption.
Industrial & Engineering Chemistry Research, 2019
In this paper, the behaviour of newly formed phases synthesised from fly ash in a medium-high tem... more In this paper, the behaviour of newly formed phases synthesised from fly ash in a medium-high temperature range (60-105 °C) was studied by X-ray powder diffraction. X-ray diffraction data indicate that up to 90 °C, the main zeolites formed are X-type zeolite and sodalite; at higher incubation temperature (95-105 °C) gmelinite also formed together with sodalite. Rietveld quantitative analysis shows that the amount of amorphous material (geopolymer) does not change up to 90 °C and instead it strongly increases after 95 °C. An opposite trend characterizes the behaviour of X-type zeolite and sodalite. Beyond the confirmation of a complex competitive system, this study highlights the metastable behaviour of newly formed zeolites in a very short range of temperature at fixed NaOH concentration and it shows the role played by the amorphous phase.
Microporous and Mesoporous Materials, 2018
Zeolite synthesis typically requires batch systems (precursor mixture) in which aluminate and sil... more Zeolite synthesis typically requires batch systems (precursor mixture) in which aluminate and silicate solutions are first mixed and then subjected to hydrothermal treatment. In this study, FAU and GIS types zeolite with wool ball-like morphology were synthesized using colloidal silica and red mud as an alternative aluminium source. The addition of aluminium powder to the precursor mixture composed by colloidal silica and red mud resulted in the crystallization of pure GIS-type zeolite with a cactus-like morphology. The crystalline products (GIS and FAU zeolites) were thoroughly characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and nitrogen adsorption. In addition, the magnetic properties of the zeolites were studied since the red mud used as aluminium source is mainly containing a mixture of magnetic iron-based oxides. The magnetic zeolites will be further considered for wastewater treatment, as they can be easily separated using an external magnetic field.
Uploads
Papers by Francesco Cavalcante