Elimination of pesticides by natural and modified clays

2018 ◽  
Vol 96 (11) ◽  
pp. 975-983
Author(s):  
Faiza Bouazza ◽  
Belkacem Benguella ◽  
Sarah Soussi
Keyword(s):  
Waste Treatment ◽  
Physicochemical Characterization ◽  
Exchange Capacity ◽  
Natural State ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Clays ◽  
Scanning Electron Microscopy Measurement ◽  
Microscopy Measurement ◽  
Natural Clays

The objective of this study is the variation of natural and modified clays and their use in industrial waste treatment. For this purpose, we carried out several elimination tests of the effluents by adsorption by using two natural clays from different deposits, namely bentonite located in Maghnia and Djabel Debbagh of Ain Berbar and bentonite coupled with cellulose. The adsorption test was performed on a Decis pesticide. The clays that we tested, in the natural state and in the modified state, are the object of a mineralogical and physicochemical characterization by various techniques of analysis: X-ray diffraction, chemical composition, spectroscopy infrared, cation exchange capacity, scanning electron microscopy, measurement of specific surface area, and various adsorption tests concerning kinetics and capacity, as well as kinetic and thermodynamic modeling and adsorption isotherms. The results showed the practical use of clays for the decontamination of waters contaminated by organic pollutants.

scholarly journals Physicochemical Characterization of Moroccan Natural Clays and the Study of their Adsorption Capacity for the Methyl Orange and Methylene

2020 ◽  
Vol 8 (4) ◽  
pp. 1258-1267
Keyword(s):  
Methyl Orange ◽  
Physicochemical Characterization ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
Calcined Clay ◽  
X Ray ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Natural Clays

The objective of this work was the physicochemical characterization of a Moroccan natural clay from the Jorf Arfoud region (Lampert Coodinates: x = 595610, y = 101578) and its valorization in the elimination of organic pollutants (methyl orange MO and methylene blue MB) from aqueous solutions, with the adsorption technique on raw and calcined clay at 500°C. The clay was characterized by chemical analysis such as X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning electron microscopy (SEM). Crude and purified clays, consisting essentially of silica and alumina, are a characteristic property of phyllosilicates and also contain amounts of quartz, kaolinite and calcite as associated minerals. The experiments were performed after optimization of the parameters influencing the system, such as pH, adsorbent mass, initial dye concentration and temperature. The clays used absorb better the MB than MO, for an initial concentration of 10 mg/L and 20 mg/L respectively. Langmuir and Freundlich models of adsorption isotherms were applied to fit experimental equilibrium data. Results have showed that the adsorption of MB and MO followed very well the second order kinetic model on raw clay. The adsorption process was found to be exothermic in the case of MB. However, the adsorption of MO was endothermic.

scholarly journals Solid desiccants from natural and modified bentonites

Cerâmica ◽  
2018 ◽  
Vol 64 (372) ◽  
pp. 526-537
Author(s):  
N. Castrillo ◽  
A. Mercado ◽  
C. Volzone
Keyword(s):  
Water Adsorption ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Hydration Degree ◽  
X Ray ◽  
Textural Characterization ◽  
Close Relationship ◽  
Natural Clays ◽  
Bentonite Clays ◽  
Adsorption Desorption

Abstract The aim of the present work was to study Argentinean natural clays with different modifications and their use as desiccants. To this end, bentonite clays collected from different regions were characterized and modified by heat treatment and calcium addition, and the desiccant capacity, in the form of powder and pellets, was studied. In addition, the hydration degree reversibility of these materials was estimated. The mineralogical and structural characterization was performed by X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, and thermogravimetric analysis. The textural characterization was performed by adsorption-desorption of N2, chemical composition by X-ray fluorescence and cation exchange capacity. The water adsorption was determined at 25 °C between 11-98% relative humidity. The results indicated that the desiccant power has a close relationship with the degree of clay purity, drying of the sample and the method of calcium incorporation.

scholarly journals Characterization of Colombian Clay and Its Potential Use as Adsorbent

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Iván Fernando Macías-Quiroga ◽  
Gloria Inés Giraldo-Gómez ◽  
Nancy Rocío Sanabria-González
Keyword(s):  
Aqueous Solution ◽  
Physicochemical Characterization ◽  
Nitrogen Adsorption ◽  
Xrd Analysis ◽  
Exchange Capacity ◽  
Hexadecyltrimethylammonium Bromide ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals

This paper presents a mineralogical and physicochemical characterization of a Colombian clay found in an area with the greatest exploitation potential of smectites and possible use as an adsorbent for the removal of chromium. The clay was characterized by using X-ray diffraction (XRD), cation exchange capacity (CEC), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FT-IR), thermal analysis (TGA/DSC), and nitrogen adsorption at 77 K. The homoionized clay was used as an adsorbent for the removal of Cr(III) in an aqueous solution. The homoionized clay was modified with hexadecyltrimethylammonium bromide (HDTMA-Br), and the organoclay obtained was evaluated for the adsorption of Cr(VI) in aqueous solution. The XRD analysis showed that the clay from Armero-Guayabal is primarily constituted by smectite (48 wt%) followed by quartz mineral (21 wt%). The chemical analysis of bulk clay showed that the predominant oxides are SiO2 (55.81 wt%), Al2O3 (16.25 wt%), and Fe2O3 (7.51 wt%), and the nitrogen adsorption indicated that the bulk clay has a specific surface area of 45.1 m2/g. Homoionized clay and organoclay achieved Cr(III) and Cr(VI) removals greater than 85.05 ± 2.04% (pH between 3 and 4) and 82.93 ± 1.03% (pH between 3 and 5), respectively, proving the potential of these materials for the removal of heavy metals in an aqueous solution.

Cadmium Sulphide Nanocrystallites for Optoelectronic Devices

2019 ◽  
Vol 969 ◽  
pp. 237-241
Author(s):  
R. Sivanand ◽  
S. Chellammal ◽  
S. Manivannan
Keyword(s):  
Diffraction Method ◽  
Cadmium Sulphide ◽  
Precipitation Method ◽  
Energy Dispersive Analysis ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Morphological Studies ◽  
Scanning Electron Microscopy Measurement ◽  
Microscopy Measurement

Cadmium sulphide nanocrystallites have been synthesized using precipitation method. The average sizes of the prepared samples is determined by XRD (x-ray diffraction) method. Morphological studies are carried out by SEM (scanning electron microscopy) measurement. Necesssary elements present in prepared samples, are confirmed by EDAX (energy dispersive analysis of x-ray spectroscopy) method. By Ultraviolet visible spectroscopy measurement, the value of absorption wavelength, band gap values are calculated in optical method. The electrical properties are analysed using impedance analyser measurement for the Nanocrystallites.

A mineralogical identification of a Tunisian clayey soil and fabric changes during wetting

Clay Minerals ◽  
2010 ◽  
Vol 45 (3) ◽  
pp. 315-326 ◽  
Author(s):  
H. Souli ◽  
J.-M. Fleureau ◽  
M. Trabelsi Ayadi ◽  
N. Kbir-Ariguib
Keyword(s):  
Clayey Soil ◽  
Thermal Analyses ◽  
Physicochemical Characterization ◽  
Swelling Pressure ◽  
Interlayer Spacing ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Physicochemical Methods ◽  
Points Of View

AbstractA clayey soil from southern Tunisia has been studied in order to assess its possible use as an anti-pollution barrier. The soil has been characterized from both geotechnical and physicochemical points of view. The physicochemical characterization was carried out using X-ray diffraction, thermogravimetric and differential thermal analyses, specific surface area and cation exchange capacity measurements. Hydration tests were carried out using oedometers to determine the swelling behaviour of compacted specimens under different stress conditions. The large swelling pressure (420 kPa) is in agreement with the mainly smectitic character of the soil highlighted by the physicochemical tests. The changes in the fabric of the soil and in its porosity after the hydration tests were investigated using the same physicochemical methods, and related to the macroscopic hydro-mechanical properties. X-ray diffraction and mercury intrusion measurements show that there are changes in the interlayer spacing, particle size and inter-aggregate pore distribution. Comparing the properties of the soil with the Belgian guidelines for the construction of anti-pollution barriers showed that the material was suitable for that use.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

scholarly journals Assay and physicochemical characterization of the antiparasitic albendazole

2012 ◽  
Vol 48 (2) ◽  
pp. 281-290 ◽  
Author(s):  
Noely Camila Tavares Cavalcanti ◽  
Giovana Damasceno Sousa ◽  
Maria Alice Maciel Tabosa ◽  
José Lamartine Soares Sobrinho ◽  
Leila Bastos Leal ◽  
...  
Keyword(s):  
Physicochemical Characterization ◽  
Analytical Techniques ◽  
Assay Method ◽  
Active Pharmaceutical Ingredients ◽  
X Ray Diffraction ◽  
Melting Points ◽  
X Ray ◽  
Pharmaceutical Ingredients ◽  
Complementary Techniques

The aim of this study was to characterize three batches of albendazole by pharmacopeial and complementary analytical techniques in order to establish more detailed specifications for the development of pharmaceutical forms. The ABZ01, ABZ02, and ABZ03 batches had melting points of 208 ºC, 208 ºC, and 209 ºC, respectively. X-ray diffraction revealed that all three batches showed crystalline behavior and the absence of polymorphism. Scanning electron microscopy showed that all the samples were crystals of different sizes with a strong tendency to aggregate. The samples were insoluble in water (5.07, 4.27, and 4.52 mg mL-1, respectively) and very slightly soluble in 0.1 M HCl (55.10, 56.90, and 61.70 mg mL-1, respectively) and additionally showed purities within the range specified by the Brazilian Pharmacopoeia 5th edition (F. Bras. V; 98% to 102%). The pharmacopeial assay method was not reproducible and some changes were necessary. The method was validated and showed to be selective, specific, linear, robust, precise, and accurate. From this characterization, we concluded that pharmacopeial techniques alone are not able to detect subtle differences in active pharmaceutical ingredients; therefore, the use of other complementary techniques is required to ensure strict quality control in the pharmaceutical industry.

scholarly journals Preparation, Physicochemical Characterization, and Microrobotics Applications of Polyvinyl Chloride- (PVC-) Based PANI/PEDOT: PSS/ZrP Composite Cation-Exchange Membrane

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Mohd Imran Ahamed ◽  
Inamuddin ◽  
Abdullah M. Asiri ◽  
Mohammad Luqman ◽  
Lutfullah
Keyword(s):  
Physicochemical Characterization ◽  
Solution Casting ◽  
Polystyrene Sulfonate ◽  
X Ray Diffraction ◽  
Casting Method ◽  
X Ray ◽  
Solution Casting Method ◽  
Exchange Membrane ◽  
Differential Thermogravimetry ◽  
Aniline Polymerization

Poly(3,4-ethylene dioxythiophene): polystyrene sulfonate (PEDOT: PSS) zirconium(IV) phosphate (ZrP) based ionomeric membrane was prepared by a solution-casting method. Subsequently, aniline polymerization was carried out on the surface of the membrane by oxidative chemical polymerization. It was characterized by thermogravimetric analysis/differential thermal analysis/differential thermogravimetry (TGA/DTA/DTG), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) analysis, and Fourier-transform infrared (FTIR) spectroscopy. The membrane was also characterized by ion-exchange properties. The tip displacement investigation of the ionomeric membrane was also carried out. The outcomes demonstrated that the manufactured ionomeric membrane could produce generative strengths (tip powers), and consequently create good displacement. In this manner, the proposed ionomeric membrane was found proper for bending movement actuator that will give a successful and promising stage for smaller-scale mechanical applications.

Nanostructured Co3O4 Oxide for Low Temperature Ethanol Oxidation

2014 ◽  
Vol 798-799 ◽  
pp. 205-210
Author(s):  
Jairo Alberto Gomez-Cuaspud ◽  
Martin Schmal
Keyword(s):  
Ethanol Oxidation ◽  
Physicochemical Characterization ◽  
Fluorescence Analysis ◽  
Product Distribution ◽  
X Ray Diffraction ◽  
Ethanol Oxidation Reaction ◽  
Reaction Conditions ◽  
X Ray ◽  
Temperature Programmed ◽  
Combustion Technique

We investigated the synthesis of nanosized Co3O4 oxide by the polymerization-combustion technique, with different concentrations (3, 12 and 25% w/w) in the ethanol oxidation reaction. Characterization was done by X-ray fluorescence analysis, X-ray diffraction, temperature programmed reduction, scanning and transmission electronic microscopy and CO and H2 chemisorption. Principal results from physicochemical characterization show that the concentration of the metal oxide influence the product distribution and selectivity under isothermal conditions at 420 °C showed the formation of intermediate etoxi-species and preferential dehydrogenation reaction on stream of material. Specific concentrations result in high conversions and H2 selectivity under present reaction conditions.

scholarly journals Purification, Characterization, and Time-Dependent Adsorption Studies of Ghanaian Muscovite Clay

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Samuel Tetteh ◽  
Andrews Quashie ◽  
Michael Akrofi Anang
Keyword(s):  
Exchange Capacity ◽  
Time Dependent ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Adsorption Studies ◽  
Morphological Studies ◽  
Ft Ir ◽  
Crystalline Nature ◽  
Different Parts

Three clay samples (E1, E2, and C1) extracted from different parts of Ghana have been purified by sedimentation. The samples were further characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), cation exchange capacity (CEC), and point of zero charge (pHpzc). PXRD and FT-IR data revealed the samples to be predominantly muscovite clay with percentages ranging from 82.71 to 91.33%. The surfaces were mostly cationic with pHpzc ranging from 5.58 to 6.40. Morphological studies by SEM confirmed the crystalline nature of the surfaces which is suitable for adsorption studies. Time-dependent adsorption studies show that C1 is a good candidate for the adsorption of chlorophenols, methyl orange, and Eriochrome Black T.

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