Natural clay from Cuba for environmental remediation

Clay Minerals ◽  
2018 ◽  
Vol 53 (2) ◽  
pp. 193-201 ◽  
Author(s):  
S. A. Martín ◽  
L. Valdés ◽  
F. Mérida ◽  
L. C. de Ménorval ◽  
M. Velázquez ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Low Cost ◽  
Industrial Effluents ◽  
Xrd Analysis ◽  
Natural Clay ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
Ph Values ◽  
Natural Clays ◽  
Adsorptive Properties

ABSTRACTThe use of natural clays for the removal of dyes from wastewater, an important part of environmental remediation, is desirable due, not least, to their low cost. Palygorskite (PAL), a rigid-structure clay, is a good candidate for use in the elimination of industrial effluents, based on its exceptional adsorptive properties. Recently, a new palygorskite deposit has been discovered in Cuba and its use in the adsorption of dyes has not yet been explored in detail. In the present study, the use of unmodified natural Cuban palygorskite as a host for dyes was evaluated. Congo red (CR) and methylene blue (MB) were the anionic and cationic dyes tested, respectively, because of their wide use and toxicity to the environment. Several physical-chemical parameters were studied in order to establish the best experimental conditions under which to achieve the greatest dye load per gram of clay. Natural mixtures with different percentages of montmorillonite were also tested to evaluate their effect on the adsorption of the dyes. The results indicated that at pH values of ~7–9 and an initial dye concentration of 0.1 mg mL–1, the process was efficient. X-ray diffraction (XRD) analysis proved the surface adsorption of both dyes on the clays. The main interactions involved in the clay-dye system were electrostatic forces and H-bonds. Adsorption of CR seemed to be controlled fundamentally by the palygorskite phase. Such results support the use of this natural clay as an efficient host for the removal of MB and CR from wastewater.

scholarly journals Use of Lignite as a Low-Cost Material for Cadmium and Copper Removal from Aqueous Solutions: Assessment of Adsorption Characteristics and Exploration of Involved Mechanisms

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 164
Author(s):  
Salah Jellali ◽  
Ahmed Amine Azzaz ◽  
Mejdi Jeguirim ◽  
Helmi Hamdi ◽  
Ammar Mlayah
Keyword(s):  
Aqueous Solutions ◽  
Low Cost ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
Experimental Conditions ◽  
X Ray ◽  
Ph Values ◽  
Adsorption Capacities ◽  
Or Groups ◽  
Pseudo Second Order

Lignite, as an available and low-cost material, was tested for cadmium (Cd) and copper (Cu) removal from aqueous solutions under various static experimental conditions. Experimental results showed that the removal efficiency of both metals was improved by increasing their initial concentrations, adsorbent dosage and aqueous pH values. The adsorption kinetic was very rapid for Cd since about 78% of the totally adsorbed amounts were removed after a contact time of only 1 min. For Cd and Cu, the kinetic and isothermal data were well fitted with pseudo-second order and Freundlich models, respectively, which suggests that Cd/Cu removal by lignite occurs heterogeneously on multilayers surfaces. The maximum Langmuir’s adsorption capacities of Cd and Cu were assessed to 38.0 and 21.4 mg g−1 and are relatively important compared to some other lignites and raw natural materials. Results of proximate, scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR) and X-Ray diffraction (XRD) showed that the removal of these metals occurs most likely through a combination of cation exchange and complexation with specific functional groups. The relatively high adsorption capacity of the used lignite promotes its future use as a low cost material for Cd and Cu removal from effluents, and possibly for other heavy metals or groups of pollutants.

scholarly journals Corrosion properties of Zn-Ni-P alloys in neutral model medium

2014 ◽  
Vol 12 (11) ◽  
pp. 1183-1193 ◽  
Author(s):  
Vassil Bachvarov ◽  
Miglena Peshova ◽  
Stefana Vitkova ◽  
Nikolai Boshkov
Keyword(s):  
Corrosion Resistance ◽  
Xrd Analysis ◽  
Ternary Alloys ◽  
X Ray Diffraction ◽  
Model Medium ◽  
Experimental Conditions ◽  
Corrosion Properties ◽  
X Ray ◽  
Protective Ability ◽  
Corrosion Medium

AbstractThe presented work reports on the peculiarities of the anodic behavior, corrosion resistance and protective ability of electrodeposited Zn-Ni-P alloys with a different composition in a model corrosion medium of 5% NaCl. Three characteristic coating types have been investigated using experimental methods such as potentiodynamic polarization (PD) technique and polarization resistance (Rp) measurements. In addition, X-ray diffraction (XRD) analysis as well as scanning electron microscopy (SEM) coupled with an Energy-dispersive X-ray (EDAX) device were applied to determine the differences in the chemical composition and surface morphology which appeared as a result of the corrosion treatment. The data obtained are compared to those of electrodeposited pure Zn coatings with identical experimental conditions demonstrating the enhanced protective characteristics of the ternary alloys during the test period in the model medium. The influence of the chemical and phase composition of the alloys on its corrosion resistance and protective ability is also commented and discussed.

HT-XRD Analysis of W Thick Coatings for Nuclear Fusion Technology

2014 ◽  
Vol 605 ◽  
pp. 31-34
Author(s):  
Girolamo Costanza ◽  
R. Donnini ◽  
Saulius Kaciulis ◽  
Giorgio Maddaluno ◽  
Roberto Montanari
Keyword(s):  
Nuclear Fusion ◽  
Low Cost ◽  
Deposition Process ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Extended Surfaces ◽  
Thick Coatings ◽  
Thermal Shields ◽  
Soft Interface

W is a promising material to use as protection for thermal shields in future nuclear fusion reactors, however the joining to other metals is really challenging. For realizing such joints plasma spraying (PS) has been used for its simplicity, the possibility to cover complex and extended surfaces and the relatively low cost. An appropriate interlayer must be optimized to increase the adhesion of W on the substrates and to provide a soft interface for better thermo-mechanical compatibility.The present work demonstrates that high-temperature X-ray diffraction (HT-XRD) permits to quickly assess the reliability and quality of the coating-interlayer-substrate system by measuring the strain of coating. This is very useful to orientate the work for optimizing the structure and composition of the interlayer and the parameters of deposition process.

scholarly journals Potential Use of Green Synthesized Al2O3 (Alumina) Nanoparticles from Guava Leaves (Psidium guajava) for the Removal of Methylene Blue from Wastewater

2021 ◽  
Vol 33 (6) ◽  
pp. 1304-1308
Author(s):  
Debasish Mondal ◽  
Dipankar Mahata ◽  
Kamala Mandy Hansda ◽  
Sourav Mondal ◽  
Ajit Das
Keyword(s):  
Methylene Blue ◽  
Low Cost ◽  
Xrd Analysis ◽  
Psidium Guajava ◽  
Alumina Nanoparticles ◽  
X Ray Diffraction ◽  
Guava Leaves ◽  
Al2o3 Nps ◽  
Potential Use ◽  
Significant Attention

Recently non-harmful nanomaterials have acquired critical significant attention in wastewater treatment containing organic pollutants especially toxic and hazardous dyes. In this regard, a low cost and eco friendly method has been investigated for the green synthesis of alumina nanoparticles (Al2O3 NPs). The alumina nanoparticles were synthesized using an aqueous extract of Psidium guajava leaf as a potential stabilizing agent. The UV-visible spectroscopy, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) techniques were used to characterize the synthesized nanoparticles. The absorption at 281 nm confirmed the formation of alumina nanoparticles. The FTIR spectra and XRD analysis confirmed the presence of various functional groups and crystalline structures of Al2O3 NPs during the synthesis. The spectrum clearly indicates the organic moieties in Psidium guajava extract are responsible for the biosynthesis of Al2O3 NPs. The suface morphology of Al2O3 NPs was confirmed by SEM and EDS studies. Besides this, the removal of methylene blue through adsorption and kinetic study was also reported.

scholarly journals Adsorption of Crystal Violet onto an Agricultural Waste Residue: Kinetics, Isotherm, Thermodynamics, and Mechanism of Adsorption

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Ilyasse Loulidi ◽  
Fatima Boukhlifi ◽  
Mbarka Ouchabi ◽  
Abdelouahed Amar ◽  
Maria Jabri ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Low Cost ◽  
Agricultural Waste ◽  
X Ray Diffraction ◽  
Almond Shell ◽  
Experimental Conditions ◽  
Batch Mode ◽  
Crystal Violet Dye ◽  
Pseudo Second Order ◽  
Effectiveness And Efficiency

Agricultural waste can be exploited for the adsorption of dyes, due to their low cost, availability, cost-effectiveness, and efficiency. In this study, we were interested in the elimination of crystal violet dye, from aqueous solutions, by adsorption on almond shell-based material, as a low-cost and ecofriendly adsorbent. The almond shells were first analyzed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction; then, the influence of adsorbent dose, initial dye concentration time, and pH were studied to assess adsorption capacity under optimal experimental conditions. Experimental results indicate that almond shell adsorbent removes about 83% of the dye from the solutions at room temperature and in batch mode; the kinetic study showed that the equilibrium time is about 90 min, and the model of pseudo-second order could very well describe adsorption kinetics. The modulation of adsorption isotherms showed that retention follows the Langmuir model. The thermodynamic study has shown that the adsorption is endothermic (ΔH° > 0) and spontaneous (ΔG° < 0).

A facile synthesis method and fracture toughness evaluation of catfish bones-derived hydroxyapatite

MRS Advances ◽  
2020 ◽  
Vol 5 (26) ◽  
pp. 1357-1366
Author(s):  
E.S Akpan ◽  
M. Dauda ◽  
L.S Kuburi ◽  
D.O Obada
Keyword(s):  
Fracture Toughness ◽  
Low Cost ◽  
Synthesis Method ◽  
Xrd Analysis ◽  
Treatment Method ◽  
X Ray Diffraction ◽  
Toughness Evaluation ◽  
Crystallite Sizes ◽  
Heat Treatment Method ◽  
Fracture Toughness Evaluation

AbstractIn this study, biological hydroxyapatite (HAp) was synthesized from catfish (Pangasius hypophthalmus) bones. First, the as-received catfish bones were de-proteinized in open air, and then converted to HAp by a solid state heat treatment method at a temperature of 900 °C for a holding time of 2 h in a muffle furnace. X-ray diffraction (XRD) analysis confirmed that HAp with high crystallinity of 99.9% was formed matching the structural properties of flouro-apatite with crystallite sizes of approximately 37.1 nm. The morphology of the HAp prepared showed irregularly shaped particles and revealed the appearance of open pores with a less agglomerated structure and a Ca/P ratio of about 1.58. The specific mechanical properties: hardness, compressive strength and fracture toughness of the catfish derived scaffolds were recorded as 480 MPa, 1.92 MPa, and 5.72 Mpa.m1/2, respectively. The fracture toughness of the HAp derived scaffolds suggests that the produced biomaterial is promising for biomedical applications. These findings are useful for the production and application of the HAp powders prepared from catfish bones, and further suggests a possible low-cost route for producing inexpensive ceramics using natural catfish bones.

scholarly journals Characterization of magnetic biochar amended with silicon dioxide prepared at high temperature calcination

2016 ◽  
Vol 34 (3) ◽  
pp. 597-604 ◽  
Author(s):  
Shams Ali Baig ◽  
Zimo Lou ◽  
Malik T. Hayat ◽  
Ruiqi Fu ◽  
Yu Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Silicon Dioxide ◽  
Environmental Remediation ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Magnetic Biochar ◽  
Ft Ir ◽  
High Temperature Calcination

AbstractCalcination is considered to increase the hardness of composite material and prevent its breakage for the effective applications in environmental remediation. In this study, magnetic biochar amended with silicon dioxide was calcined at high temperature under nitrogen environment and characterized using various techniques. X-ray diffraction (XRD) analysis revealed elimination of Fe3O4 peaks under nitrogen calcination and formation of Fe3Si and iron as major constituents of magnetic biochar-SiO2 composite, which demonstrated its superparamagnetic behavior (>80 A2·kg−1) comparable to magnetic biochar. Thermogravimetric analysis (TGA) revealed that both calcined samples generated higher residual mass (>96 %) and demonstrated better thermal stability. The presence of various bands in Fourier transform infrared spectroscopy (FT-IR) was more obvious and the elimination of H–O–H bonding was observed at high temperature calcination. In addition, scanning electron microscopy (SEM) images revealed certain morphological variation among the samples and the presence of more prominent internal and external pores, which then judged the surface area and pore volume of samples. Findings from this study suggests that the selective calcination process could cause useful changes in the material composites and can be effectively employed in environmental remediation measures.

scholarly journals Experiments and Thermodynamic Modeling of Chukanovite (Fe2(OH)2CO3) to High Ionic Strengths

MRS Advances ◽  
2017 ◽  
Vol 2 (13) ◽  
pp. 747-752 ◽  
Author(s):  
Sungtae Kim ◽  
Justin Dean ◽  
Jandi Knox ◽  
Leslie Kirkes ◽  
Je-Hun Jang
Keyword(s):  
Free Energy ◽  
Ionic Strength ◽  
Room Temperature ◽  
Xrd Analysis ◽  
High Ionic Strength ◽  
Model Parameters ◽  
Second Phase ◽  
Experimental Conditions ◽  
Ph Values ◽  
Decreasing Ph

ABSTRACTWhile conducting siderite (FeCO3) solubility experiments in NaCl-Na2CO3 brines, evidence for a second phase was detected. Experiments, in which synthesized siderite was reacted with high ionic strength (0.18 – 7.5 m) solutions at room temperature and high pH (>10), were conducted in a glovebox. As the aging time of siderite-bearing experiments increased, the pH of the solution decreased, signaling formation of a hydroxyl-bearing phase. Decreasing pH values are interpreted to indicate that a hydroxyl-bearing phase, such as chukanovite, is the reaction controlling solid in the solid assemblage. Chukanovite was tentatively identified by XRD analysis. We set out, therefore, to determine the thermodynamic stability of chukanovite under the experimental conditions. Aqueous thermodynamic model parameters were determined with experimentally analyzed Fe(II) solubility data, and subsequently yielded a proposed formation free energy of chukanovite (-1149.8 kJ/mol).

Electrochemical Reduction of Tetrachloromethane. Electrolytic Conversion to Chloroform

2002 ◽  
Vol 67 (3) ◽  
pp. 279-292 ◽  
Author(s):  
Victor M. Molina ◽  
Domingo González-Arjona ◽  
Emilio Roldán ◽  
Manuel Dominguez
Keyword(s):  
Supporting Electrolyte ◽  
Industrial Effluents ◽  
Differential Pulse ◽  
Experimental Conditions ◽  
Ph Values ◽  
Peak Deconvolution ◽  
Through Flow ◽  
Voltammetric Peak ◽  
Electrolysis Products ◽  
Made In

The feasibility of electrolytic removal of tetrachloromethane from industrial effluents has been investigated. A new method based on the electrochemical reductive dechlorination of CCl4 yielding chloroform is described. The main goal was not only to remove CCl4 but also to utilize the process for obtaining chloroform, which can be industrially reused. GC-MS analysis of the electrolysed samples showed that chloroform is the only product. Voltammetric experiments were made in order to select experimental conditions of the electrolysis. Using energetic and economic criteria, ethanol-water (1 : 4) and LiCl were found to be the optimum solvent and supporting electrolyte tested. No great differences were found while working at different pH values. Chronoamperometric and voltammetric experiments with convolution analysis showed low kf0 and α values for the reaction. A new differential pulse voltammetric peak deconvolution method was developed for an easier and faster analysis of the electrolysis products. Electrolysis experiments were carried out using both a bulk reactor and a through-flow cell. Thus, three different kinds of galvanostatic electrolyses were carried out. Under all conditions, CCl4 conversions ranging from 60 to 75% and good current efficiencies were obtained.

scholarly journals Characterization and Modification of Clay for Removal of Drinking Water Hardness

2021 ◽  
Vol 18 (3) ◽  
pp. 318-331
Author(s):  
Asanthi Ireshika Rukshani Wickramasuriya ◽  
Ruwan Chandima Wickramasinghe Arachchige ◽  
Iresha Renuke Menike Kottegoda
Keyword(s):  
Drinking Water ◽  
Low Cost ◽  
Water Hardness ◽  
Freundlich Isotherm ◽  
Xrd Analysis ◽  
Adsorption Efficiency ◽  
X Ray Diffraction ◽  
Cationic Modification ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Different Temperatures

Hardness in drinking water is a major problem in domestic usage. It is important to use drinking water within the tolerance limits of hardness. Clay samples obtained from two different areas in Sri Lanka were analysed, modified, and optimized with a view to suppress the hardness in drinking water. Characterization of clay was carried out using XRD (X-ray diffraction spectroscopy), FTIR (Fourier transformed infrared spectroscopy), and SEM (Scanning electron microscope). Variation of the adsorption capacity of clay was analysed at different firing temperatures of the clay samples. XRD analysis revealed that both clay types are consisting of Kaolinite as the main constituent. The hardness adsorption efficiency and the retention of hardness adsorption in prolonged cycles has been observed when the clay is heated at different temperatures. In addition, the water hardness adsorption efficiency was enhanced by the cationic modification using sodium chloride. The results further reveals that the Freundlich isotherm is best fit for Ca2+ adsorption on both Biyagama and Deniyaya clay whereas that for the Mg2+ adsorption is Langmuir isotherm. The present study is useful to develop low-cost clay-based materials to minimize water hardness.

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