scholarly journals Characterization of Leca Clay Pebbles as a Growing Medium for Geranium (Pelargonium hortorum) Stock Plant Production

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 902F-902
Author(s):  
Mana Libran ◽  
David J. Williams

Leca clay pebbles were characterized and tested as a possible growing-medium for use in floriculture production systems that recycle irrigation water. Leca clay pebbles are light porous particles made by heating clay. X-ray diffraction tests indicate that high manufacturing temperatures (1100C) result in final particles composed primarily of quartz. Water-holding capacity was determined by pressure plate apparatus at eight pressures. Leca particles that were 4 to 8 mm retained more water than particles sized 12 to 18 mm. The bulk density of the particles were 0.43 and 0.37 g/cc for the 48-mm and the 12- to 18-mm particles, respectively. The pH of the leca particles was 7.77. The cation exchange capacity of the leca particles was relatively low compared to a standard soilless growing medium of 1 pine bark: 1 peat: 1 perlite (by volume). Leca particles have a CEC of o.82 me/100 g Ca and 6.36 me/100 g K, where the CEC of the previously mentioned soilless.medium was 24.21 me/100g Ca and 30.08 me/100 g K. Leca clay pebbles were tested as growing medium for the production of geraniums (Pelargonium hortorum) stock plants.

2012 ◽  
Vol 727-728 ◽  
pp. 1591-1595 ◽  
Author(s):  
Aline Cadigena Lima Patrício ◽  
Marcílio Máximo da Silva ◽  
Anna Karoline Freires de Sousa ◽  
Mariaugusta Ferreira Mota ◽  
Meiry Glaúcia Freire Rodrigues

Cationic surfactants, such as quaternary ammonium cations, have been used, in order to ameliorate the oil sorption capacity of inorganics materials, such as clays. Clays modified with quaternary ammonium cations (organoclays) have better performance in sorption, remove oil and grease from water at seven times the rate of activated carbon, as well as they can be used like perforation fluids of oil wells to the oil base, lubricants, among others industries. This work aims characterize the Cloisite 30B using various techniques: X-Ray Diffraction (XRD), Specific Surface Area (BET) and Cation Exchange Capacity. Different organic solvents, namely gasoline, diesel and kerosene were used in order to investigate the clays compatibility after orgophilization.


2015 ◽  
Vol 820 ◽  
pp. 51-55
Author(s):  
I.A. Silva ◽  
I.D.S. Pereira ◽  
W.S. Cavalcanti ◽  
F.K.A. Sousa ◽  
Gelmires Araújo Neves ◽  
...  

The State of Paraíba has gained prominence in the production of raw bentonite in Brazil, where a new deposit has been found in the town of Sossego-PB, besides the deposit in the town of Boa Vista-PB. With the raise in the demand, the traditional reserves are depleting after several years of exploration, and this fact may result in a higher dependence on imported clays, thus existing a great interest in the discovery and characterization of new deposits, also guaranteeing technological improvements for the region. So, the objective of this work is to characterize the new deposits of the State of Paraíba, aiming at analyzing the characteristics the prove their classification as smectitic clays. The characterization was made through the analysis of chemical composition by X-ray fluorescence (EDX), X-ray diffraction (XRD), thermogravimetric analysis and thermal differential analyses (TG and DTA), cation-exchange capacity (CEC) and specific area (SA). The results prove that the studied samples presented, in their mineralogical composition, smectite, kaolinite and quartz, besides thermal and chemical behavior typical smectitic clays.


2015 ◽  
Vol 820 ◽  
pp. 56-59
Author(s):  
F.K.A. Sousa ◽  
I.A. Silva ◽  
W.S. Cavalcanti ◽  
Gelmires Araújo Neves ◽  
Heber Carlos Ferreira

Used in various branches of the industry, bentonitic clays are considered a valuable mineral, used specially in the petroleum industry for manufacturing of fluids used the drilling of petroleum wells in long depth. Recently, a deposit of this valuable mineral was discovered in the town of Olivedos-PB. There are data that prove that this is a very poor and underdeveloped town. So, this work aims at the physico-mineralogical characterization of clays recently discovered and, this way, verify if they present similar characteristics which allow them to replace the clays from Boa Vista-PB, and if they can be used by the industry, thus bringing social development for that town. The characterization was made by means of the analysis of chemical composition by X-ray fluorescence (EDX), thermogravimetric and thermal differential analyses (TG and DTA), X-ray diffraction (XRD), cation-exchange capacity (CEC) and specific area (SA). The results show that the clays recently discovered in Olivedos-PB are polycationic clays, presenting MgO, CaO and K2O content, and that they are constituted by smectitic clay mineral, by quartz and kaolinite.


2007 ◽  
Vol 334-335 ◽  
pp. 825-828 ◽  
Author(s):  
Wei Tan ◽  
Yi He Zhang ◽  
Yau Shan Szeto ◽  
Li Bing Liao

It was shown that chitosan and hydroxy-aluminum pillared montmorillonites were excellent materials for the removal of dyes and metal ions from effluent of dying and finishing. Chitosan/ hydroxy-aluminum pillared montmorillonite nanocomposites are expected to play a multiplex role in the treating process. In this study, the nanocomposite was prepared by incorporating hydroxy-aluminum pillared montmorillonite into chitosan solution that diluted acetic acid was used as solvent for dissolving the chitosan. The ratio of chitosan to the cationic exchange capacity of the montmorillonite was about 1:1, 2:1, 3:1, 4:1 and 6:1, respectively. The nanocomposites were characterized by XRD (X-ray diffraction), SEM (Scanning Electron Microscopy). The experimental results indicated that the presence of hydroxy-aluminum cation was in favor of the chitosan intercalation and the interlayers of MMT was intercalated with the bilayers of chitosan sheets. and they can be used in absorption of organic and metal ions for dying and finishing effluent.


1965 ◽  
Vol 2 (4) ◽  
pp. 299-308 ◽  
Author(s):  
R. S. La Venture ◽  
B. P. Warkentin

Measurements of soluble components, and characterization of the charge on the mineral surfaces, are reported for five samples of the Champlain Sea sediments. Large amounts of magnesium, beyond the amount of dolomite present, were slowly released in solution from the broken surfaces of the minerals. Amorphous aluminosilicates made up less than 6% of the sample weight, and their removal did not improve the X-ray diffraction patterns or alter significantly the chemical properties of the sediments. Of the cation exchange capacity of 20 to 30 meq/100 g at pH 7, from 50 to 75% was found to be due to pH-dependent charge, which leads to preferential adsorption of monovalent ions. In equilibrium with artificial seawater, the samples had from 50 to 25% exchangeable sodium.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Iván Fernando Macías-Quiroga ◽  
Gloria Inés Giraldo-Gómez ◽  
Nancy Rocío Sanabria-González

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.


2014 ◽  
Vol 1043 ◽  
pp. 198-203 ◽  
Author(s):  
Jumaeri ◽  
Sri Juari Santosa ◽  
Sutarno ◽  
Eko Sri Kunarti

Zeolite A has been synthesized by a modified alkali fusion followed hydrothermal process. Hydrothermal was performed at a temperature of 90 °C for 4 h in a stainless steel reactor. Characterization of the synthesized zeolite was conducted using various techniques, i.e. X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) and measurement of cation exchange capacity (CEC). The characterization results showed that zeolite A was selectively obtained by this method. The diffract gram, SEM image, and IR spectra of the synthesized zeolite A showed a similarity with the commercially available zeolit A.


Cerâmica ◽  
2016 ◽  
Vol 62 (363) ◽  
pp. 272-277 ◽  
Author(s):  
C. I. R. de Oliveira ◽  
M. C. G. Rocha ◽  
A. L. N. da Silva ◽  
L. C. Bertolino

Abstract Clays of different composition have been used in the development of polymer nanocomposites. The utilization of bentonite clays of the State of Paraíba, Brazil, has been emphasized mainly due to their availability. However, these bentonite deposits are becoming exhausted after several years of exploitation. Thus, the aim of this work was to characterize bentonite clays recently discovered in the municipality of Cubati, Paraíba. The samples underwent a particle size classification step and were characterized by granulometric analysis by laser diffraction, X-ray fluorescence, X-ray diffraction, infrared spectroscopy, thermogravimetric analysis and cation exchange capacity. The results of particle size distribution showed that the clay samples have similar physical characteristics to bentonite clays of Boa Vista, Paraíba. Results of X-ray diffraction indicated that the mineralogical composition of the samples consisted of montmorillonite, kaolinite and quartz. The characterization of the samples by FTIR confirmed these results. Results of chemical analysis showed that the samples are polycationic bentonite clays and have predominantly different exchangeable cations similar to those seen in South American bentonites.


Author(s):  
R. E. Herfert

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


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