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espanolLa tierra de Fuller es un material adsorbente utilizado en la industria electrica para la regeneracion de aceite dielectrico. La gran cantidad de hidrocarburos poliaromaticos eliminados del petroleo y adsorbidos en la tierra de Fuller hace que este material sea un desecho peligroso. Es necesario implementar una prueba de toxicidad y aplicar un tratamiento adecuado para desechar de manera segura estos desechos en un vertedero o reciclar para su reutilizacion. En este documento, la toxicidad de la tierra de Fuller contaminada con aceite dielectrico se evalua antes y despues del tratamiento. El potencial toxico de la tierra de Fuller y el aceite dielectrico extraido mediante procesos de descontaminacion se evaluo en dos tipos de suelo con diferentes contenidos de carbono, analizando los efectos en los organismos de prueba, las lombrices de tierra Eisenia Foetida. Estas pruebas mostraron que la tierra de Fuller descontaminada no es toxica, y que la toxicidad de la tierra de Fuller contaminada, o sus extractos despues del tratamiento, representada por la concentracion letal media (CL50) depende significativamente del tipo de suelo utilizado EnglishFuller’s earth is an adsorbent material used in the electric industry for dielectric oil regeneration. The high amount of polyaromatic hydrocarbons removed from oil and adsorbed in the Fuller’s earth makes this material a hazardous waste. It is necessary to implement a toxicity test and apply a suitable treatment to safely dispose of this waste in a landfill or repurpose it for reuse. In this paper, the toxicity of Fuller’s earth contaminated with dielectric oil is assessed before and after treatment. The toxic potential of the Fuller’s earth and the dielectric oil extracted through decontamination processes was evaluated in two types of soil with different carbon contents, analyzing the effects on the test organisms, Eisenia Foetida earthworms. These tests showed that decontaminated Fuller’s earth is non-toxic, and that the toxicity of the contaminated Fuller’s earth, or its extracts after treatment, represented by the median lethal concentration (LC50) depends significantly on the type of soil used.

The present work focuses on the remediation of Methylene Blue dye (MB) by adsorption on Fuller's earth clay (FE). The optimum batch limits for MB adsorption are; pH 8; equilibration time 3 ​h; initial concentration 100 ​mg ​L−1; agitation speed 300 ​rpm; a dose of adsorbent 2 ​g ​L−1, and temperature 25 ​°C. FE clay was characterized using XRD and FESEM. XRD analysis indicated montmorillonite to be the major component of FE. FESEM images indicated clay surface to be layered with high surface area and porosity thereby making it an excellent material for dye adsorption. Classical Langmuir, Modified Langmuir, Freundlich, and BET adsorption isotherms were studied to investigate the adsorption mechanism of MB on FE. Modified Langmuir isotherm fits well for adsorption of MB on FE with an adsorption capacity of 11587 ​mg ​g−1. Kinetic studies revealed the adsorption process to follow Pseudo Second-order kinetics with the energy of activation 28 ​kJ/mol, indicating the adsorption process to be physisorption. Thermodynamic studies indicated the adsorption process to be spontaneous and endothermic. The Artificial Neural Network (ANN) model was employed in the FE system, and the model confirmed its applicability. According to error analysis, ANN was found to be more appropriate model than pseudo second-order model. Sensitivity calculations from ANN data indicated the pH of adsorption to be the most influential factor in MB adsorption with 29% relative importance. The sorption process may be practically valuable on an industrial scale to remediate MB from water assets at an economical price.

Pyridine is a ubiquitous privileged heteroaromatic found in numerous natural products, including vitamins B3 and B6, nicotine, and nicotinamide adenine dinucleotide phosphate (NADP).1–4 The pyridin...

Fuller’s earth (FE) is a phyllosilicate used as a powder for household or skin decontamination due to its adsorbent properties. Recent studies have shown that water suspensions exhibit similar adsorbent capacities. FE is heterogeneous due to its composition of elementary clay aggregates and heavy metal particles. Here, FE toxicity was assessed in vitro on skin cells and in vivo on Danio rerio embryos. Among the suspensions tested (5%, 9.1% and 15% w/w), only the highest one shows weak toxicity. Suspensions were tested for ex vivo dermal decontamination into pig ear skin and human abdominal skin using diffusion cells and paraoxon as organophosphorus contaminant. After 24 hours of diffusion, no difference was observed in the paraoxon concentration in the receptor compartment whether the decontamination was carried out with FE in powder or in suspension form. In presence of FE suspensions, we observed the disappearance of paraoxon from the stratum corneum, the reservoir compartment, independently of the suspensions’ concentration. We suggest that water potentiates the absorbing capacities of FE powder by intercalating between clay lamellas leading to the appearance of new adsorption zones and swelling. These data support the use of FE aqueous suspensions as a safe tool for organophosphorus skin decontamination.

This paper summarizes experimental findings of the regenerative capability of nitrogen on Fuller's earth. Regenerating new oil from aged oil involves several cycles requiring a large volume of Fuller's earth. The use of large amounts of Fuller's earth is not economically profitable for companies that carry out regenerative operations to service transformer oils and can have environmental implications, since Fuller's earth is usually used to reclaim transformer oil in a one-time batch basis then disposed of. To improve the situation, a new technique to reduce the number of regeneration cycles is proposed. It is shown that Fuller's earth can be improved by purging it with continuous flowing of a fluid, preferably dry nitrogen., Petroleum engineering; Earth Sciences; Environmental Science; Geochemistry; Power Transformer; Electrical Insulation; High Voltage Engineering; Dielectrics Materials

MgO decked few layer Graphene Coated Fullers' Earth (MgO-FLG-FE) is prepared by microwave irradiation and tested as adsorbent to remove Acid Blue 9 (AB9) and Safranin O (SO) dye from aqueous solutions. MgO-FLG-FE was characterized by FTIR, XRD, FESEM, HRTEM, RAMAN, and BET. The adsorbent dose required for the maximum removal of AB9 and SO dyes are 1.0 g and 0.08 g which is in very low quantity compared with FE. The contact time to achieve equilibrium is 120 min in both the dyes. Langmuir, Freundlich and Dubinin-Radushkevich adsorption isotherms are applied to understand the adsorption mechanism for both the dyes in aqueous solutions. The uptake of AB9 and SO dye by MgO-FLG-FE is best explained by Langmuir adsorption isotherm. The adsorption capacities of MgO-FLG-FE for AB9 and SO are 37.7 mg/g and 201.1 mg/g respectively when compared with Fuller's Earth (36.7 mg/g and 131.19 mg/g). The adsorbent capacity of FE was enhanced by coating with very small amount of MgO decked FLG. The Pseudo-second order equation is best explained through the adsorption kinetics in this study.

SUMMARY Aflatoxicosis is a major problem associated with poultry production in the tropics. We tested the ability of 3 low-cost and locally available adsorbents (activated charcoal, bentonite, and fuller’s earth) to detoxify poultry feeds contaminated with aflatoxin. Bentonite was the most effective adsorbent and lowered the total aflatoxin concentration from 120 ± 38 μg/kg to 15 ± 5.0 μg/kg. The 3 adsorbent treatments resulted in 63%–100% weight increase of the birds, compared with birds fed the untreated, aflatoxin-containing feed. The number of white blood cells in blood samples was increased by 13%–17% in birds that consumed adsorbent-treated feed, compared with the untreated, aflatoxin-contaminated feed. Hepatic lesions were also prominent in the liver of the birds fed contaminated but untreated feed but were reduced in the group that were fed the adsorbent-treated feeds, especially in the bentonite-treated feed. Conclusively, the adsorbents were able to reduce the concentration of aflatoxin in the feed and this reflected positively on the general performance of the birds.

A simple, efficient, and green method of preparation for the synthesis of highly substituted pyridines by multicomponent reaction of acetophenones, aldehydes, and ammonium acetate using activated Fuller’s earth as an effective and reusable heterogeneous catalyst is described. The advantages of the present protocol include simple procedure with an easy workup procedure, mild reaction conditions, and high yields of the products. The performance of this reaction under solvent-free conditions using heterogeneous catalysts, such as activated Fuller’s earth, could enhance its efficiency from an economic as well as ecological point of view.

Polychlorinated biphenyls (PCBs) are carcinogenic to humans and can be found in fuller's earth used for the treatment of used transformer oil. This work describes an optimization of the Fenton process for the removal of contaminants from fuller's earth. The effects of pH (2.5 and 4.0), [H

Immobilization is a method for making an enzyme more robust in the environment, especially in terms of its stability and reusability. A mutant phosphotriesterase (YT PTE) isolated from Pseudomonas dimunita has been reported to have high proficiency in hydrolyzing the Sp and Rp-enantiomers of organophosphate chromophoric analogs and therefore has great potential as a decontamination agent and biosensor. This work aims to investigate the feasibility of using Fuller’s earth (FE) as a YT PTE immobilization support and characterize its biochemical features after immobilization. The immobilized YT PTE was found to show improvement in thermal stability with a half-life of 24 h compared to that of the free enzyme, which was only 8 h. The stability of the immobilized YT PTE allowed storage for up to 4 months and reuse for up to 6 times. The immobilized YT PTE showed high tolerance against all tested metal ions, Tween 40 and 80 surfactants and inorganic solvents. These findings showed that the immobilized YT PTE became more robust for use especially with regards to its stability and reusability. These features would enhance the future applicability of this enzyme as a decontamination agent and its use in other suitable industrial applications.

The applicability of surfactant modified fuller's earth (SMFE) for removing 2,4-dichlorophenol (2,4-DCP) from water has been investigated through batch sorption process. Fuller's earth was treated with sodium dodecyl sulphate (SDS) for conversion of fuller's earth into surfactant modified fuller's earth. The influence of pH, agitation time, sorbent dose, temperature and initial concentration of 2,4-DCP were investigated. A strong dependence of the sorption capacity on pH was observed, the capacity increased as the pH value decreased. The sodium dodecyl sulphate increased the hydrophobicity of the sorbent and provided particular affinity for 2,4-DCP molecules. The SMFE showed high efficiency towards 2,4-DCP and > 97% removal was achieved from an initial concentration of 20 mg/L at 100 °C using pH 3. The kinetics of the sorption process was described by a pseudo-second-order kinetic model. The mechanism of sorption kinetics was investigated using intraparticle diffusion model. The sorption isotherm was consistent with the Langmuir sorption isotherm and maximum monolayer capacity of the SMFE was found to be 126.58 mg/g at room temperature. The mean adsorption energy (E) value 18.25 kJ/mol indicated chemical sorption and endothermic sorption process.

Polychlorinated biphenyls (PCBs) are carcinogenic to humans and can be found in Fuller’s earth used for the regeneration of used transformer oil. This work describes a highly selective gas chromatographic-selected ion monitoring mass spectrometric method (GC-MS/SIM) for the simultaneous determination of three Aroclor PCB congener mixtures (1242, 1254, and 1260). The separation of the PCBs could be systematically varied by changing the temperature conditions of the chromatographic column. Methods were first selected from the literature, and the resolution of the PCBs was then optimized by adjusting k* (effective retention), a (selectivity), and N (column efficiency), enabling the detection of 83 PCBs in 35 min. The extract of PCBs from Fuller’s earth was obtained by ultrasonication (employing hexane and acetone as solvents) and cleanup with Florisil and was concentrated to about 500 µL. The ions analyzed in SIM mode were divided into groups according to the similarity (m/z) of the PCB fragmentation profiles. The limits of detection (LOD) and quantification (LOQ) were 0.19 and 0.64 µg kg-1, respectively. The method developed was used to determine the PCBs present in Fuller’s earth provided by an electric power company. The mean total PCBs concentration was found 1.9 µg kg-1 in Fuller’s earth.

Transformers being one of the most expensive equipment in the networks require proper utilisation, which includes regular maintenance and application of life-extension techniques in feasible situations. Ageing process of the mineral oil and cellulose paper insulation system creates by-products such as moisture, acids and sludge, which further accelerate the degradation of the transformer insulation. Therefore, the removal of these by-products through oil regeneration could potentially prolong the lifetime of transformers. Typically, oil regeneration process includes percolation of oil through an adsorbent system followed by a filtration and a degasification process. Various sorbent types such as fuller’s earth, alumina, molecular sieves, silica-kaolin-sand mixture are used for the regeneration process. This paper investigates the acid removal performance of a modified alumina based sorbent, against two conventional sorbents i.e. fuller’s earth and alumina. It was found that the overall performance of modified alumina was higher than the conventional sorbent materials. Furthermore, all the three sorbent materials showed higher absorption capacity for low molecular weight acids than the high molecular weight acids.

Sulfur mustard (HD) and VX are potent chemical warfare agents (CWAs) that penetrate rapidly through the skin causing severe acute and prolonged injuries that might result in death. Moreover, several toxic industrial chemicals (TICS) that are being routinely used in the industry and agriculture can be as deadly and damaging. Thus, following percutaneous skin exposure, rapid removal of the toxic agent by decontamination is one of the most crucial components in the individual defense. This can be achieved by passive decontamination or by neutralization of the chemical with reactive decontaminants. Fuller’s earth powder is a well-known adsorbent, known for years as an efficient decontaminant. The aim of this chapter is to evaluate the efficacy of decontamination with Fuller’s earth powder using the pig animal model and to compare it to other common decontaminants. The experimental design included exposure to 1-μl droplets of neat HD or VX (2LD50) on the pigs’ back skin for various exposure durations up to 1 hour for HD and 5 hours for VX. The efficacy of the various decontaminants (water, M291, M295, RSDL) was evaluated using clinical evaluation and measurement of lesion area or extent of erythema following exposure to HD and clinical evaluation and measurements of cholinesterase (ChE) inhibition following exposure to VX. Fuller’s earth and RSDL were most efficient and yielded similar results under the same experimental conditions. Similar high efficacy was observed when decontamination was performed up to 30 minutes after HD skin exposure and up to 2 hours following exposure to VX. Due to the advantages of Fuller’s earth, being most efficient, safe, easy to use, inexpensive, and with long shelf life, it is recommended as a universal decontaminant which is suitable for both military personnel and civilians.

Fuller&rsquo, s earth spherical beads using chitosan as a binder were prepared for the removal of strontium ions from aqueous solution. The adsorbents were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which revealed the porous nature of the beads. The Brunauer&ndash, Emmett&ndash, Teller (BET) surface area of the beads was found to be 48.5 m2/g. The adsorption capacities of the beads were evaluated under both batch and dynamic conditions. The adsorption capacity was found to be ~29 mg/g of adsorbent at 298 K when the equilibrium concentration of strontium in the solution was 925 mg/L at pH 6.5. The X-ray photoelectron spectroscopy (XPS) data suggest that strontium uptake by the beads occurs mainly through an ion-exchange process. Kinetic data indicate that the sorption of strontium onto the beads follows anomalous diffusion. Thermodynamic data suggest that the ion-exchange of Sr2+ on the bead surface was feasible, spontaneous and endothermic in nature.

We have successfully achieved the synthesis of 2,4,5-trisubstituted imidazole by a three pot multicomponent reaction of benzil, aromatic benzaldehydes and ammonium acetate in presence of activated fuller's earth as a catalyst. The activation of fuller's earth is carried out by an organic acid, which sufficiently increased its adsorption properties. The advantages of this process are high yields, green system and efficient recovery of the catalyst, which can be reused 2–3 times without much significant effect on yield. Molecular Modelling studies viz., Lipinski rule of five, drug likeness, drug scores, toxicity profiles and other physico-chemical properties of drugs were performed using Molinspiration and Osiris software and compared with the data of standard drug molecule.

Skin decontamination following exposure to chemical agents is a most important component of the individual defense doctrine, removing the agent, ceasing its penetration and preventing secondary contamination of the first responders. The goal of the current study was to compare the efficacy of Reactive Skin Decontaminant Lotion (RSDL) and Fuller's Earth (FE) following exposure to sulfur mustard (SM) and VX, aiming to find the optimal procedure for mass casualty decontamination protocol. Decontamination efficacy was evaluated in pigs by measurement of lesion area and erythema (SM) and cholinesterase inhibition and clinical symptoms (VX). FE and RSDL were highly effective against both agents. Following SM exposure, the two decontaminants demonstrated a significant decrease in lesions' size together with the decrease in exposure duration. Likewise, skin decontamination following exposure to VX with either FE or RSDL resulted in reduction in clinical symptoms and prevention of death. Decontamination was worthwhile even if postponed, up to 30 min (SM) and 2 h (VX). In conclusion, both decontamination products were efficient in ameliorating the toxic effects even though in a different mechanism. Finally, for mass casualty scenario, FE is preferred as a universal decontaminant, considering its safety, ease of use and longer shelf life.

The present paper reports the investigations pertaining to the comparative adsorption capacity of amorphous aluminium oxide and powdered fuller’s earth (as a low-cost adsorbent) for the removal of iron impurities in commercial grade sodium sulphide. Results show that incorporation of adsorbent as small as 1% reduces the iron impurities from 1.50mg to 0.12mg, and 0.50mg with amorphous aluminium oxide and powdered fuller’s earth respectively. Under similar conditions the efficiency of adsorption of iron contents in commercial grade sodium sulphide by amorphous aluminium oxide is more than powdered fuller’s earth but low cost of fuller’s earth can make it more expedient to use. It is recommended that a combination of more efficient adsorbent with low cost adsorbent like fuller’s earth may be useful option for the removal of iron impurities in commercial grade sodium sulphide. Selection and/or Peer-review under responsibility of 6th International Conference of Materials Processing and Characterization (ICMPC 2016).

A simple and efficient method for the preparation of 5-aryl 1- H -tetrazoles was developed from various aryl nitriles and sodium azide (NaN 3 ) via [3+2] cycloaddition reaction using activated Fuller’s earth as an efficient heterogeneous catalyst. This catalyst has advantageous of cost, stability, recovery, reusability, and ecological benefits along with high product yield, and mild protocol.

Fuller’s earth immobilized nanoscale zerovalent iron (F-nZVI 1–8) were synthesized by borohydride reduction method. The iron loading of fuller’s earth immobilized nZVI was varied from 5 to 50% (w/w) in these F-nZVI 1–8. The F-nZVI 1–8 were characterized by FE-SEM–EDX, FTIR, BET, XRD and TGA. The FE-SEM analysis showed an increase in agglomeration of nZVI on the immobilized material with increase in the loading of Fe0. F-nZVI 1–8 were studied for adsorptive removal of As(III) and As(V) from aqueous solution, with an emphasis on the effect of Fe0 loading of adsorbent on arsenic remediation. Iron loading has a significant role in adsorption of As(III) and As(V) on F-nZVI, with increase in adsorption with optimum iron loading of 20% (w/w) on fuller’s earth (F-nZVI-4). However, increase in loading above 20%, resulted in no significant increase in As(III) and As(V) adsorption. The adsorption results fitted well with Langmuir and Freundlich isotherm models and the maximum adsorption capacity of F-nZVI-4 for As(III) and As(V) were observed to be 50.08 and 91.42 mg/g, respectively. The adsorption isotherm and kinetic studies indicate a rapid removal of As(III) and As(V) from the aqueous solution in the presence of F-nZVI 1-8, with an substantially high rate of removal for arsenic with F-nZVI-4.

Fuller's Earth (FE) and aluminium Silicate Coated Fuller's Earth (ASFE) are used to removing Acid Blue 9 (AB9) dye from aqueous solutions as adsorbents. The adsorption capacities of FE and ASFE are ~36.70 mg/g and ~174.22 mg/g, respectively. The adsorbent dose requested for the maximum removal of AB9 dye is 1.0 g in the case of FE, whereas it is only 0.15 g in the case of ASFE. The contact time to establish equilibrium found to be 120 min in both the dye removal. Langmuir, Freundlich and Dubinin - Radushkevich adsorption isotherms are being used to explore the adsorption mechanism. Langmuir adsorption isotherm best explained the uptake of AB9 dye by FE and ASFE, respectively. The kinetics of these adsorption processes are of pseudo-second order reactions.

The present study investigates the propensity of Fuller’s Earth, a diatomaceous earth that is cheap and abundant in several locations whose application is yet to be fully ventured, and Fuller’s Earth-Immobilized Nanoscale Zero Valent Iron in removing heavy metal contaminants, particularly Pb2+ and Cu2+ , from aqueous solutions through adsorption method. FE-nZVI were synthesized through the borohydride reduction method and subsequently characterized through SEM, FTIR, and XRD. The SEM analysis shows an increase in the agglomeration of the nZVI on the immobilized Fullers’ Earth with an increase in the loading of Fe0. Tests were conducted on various samples in order to determine the effect of three parameters on the efficiency of the adsorbent which includes the initial concentration of the heavy metal, adsorbent dosage and pH with respect to time. The results show that the FE-nZVI can be used as a new adsorbent for the sole application of heavy metal remediation in aqueous systems due to its efficiency in removing the contaminants that would allow individuals to conform to the stringent requirements dictated by environmental laws.

International audience; Industrial accidents, wars and terrorist threats are potential sources of skin contamination by highly toxic chemical warfare agents and manufacturing compounds. We have compared the time-dependent adsorption capacity and decontamination efficiency of fuller's earth (FE) for four different formulations for the molecular tracer, 4-cyanophenol (4-CP), in vitro and ex vivo using water decontamination as standard. The adsorption capacity of FE was assessed in vitro for 4-CP aqueous solutions whereas decontamination efficiency was investigated ex vivo by tracking porcine skin 4-CP content using attenuated total reflectance Fourier transform infrared spectroscopy. Decontamination was performed on short time, exposed porcine skin to 4-CP by application of FE: (1) as free powder; (2) loaded on adhesive tape; (3) on powdered glove; or (4) in suspension. Removal rate of 4-CP from aqueous solutions correlates with the amount of FE and its contact time. Decontamination efficiency estimated by the percentage of 4-CP recovery from contaminated porcine skin, achieved 54% with water, ranged between ~60 and 70% with dry FE and reached ~90% with FE suspension. Successful decontamination of the FE suspension, enabling a dramatic reduction of skin contamination after a brief exposure scenario, appears to be rapid, reliable and should be formulated in a new device ready to use for self-application.

In the present study, fuller's earth (FE) was modified with sodium dodecyl sulfate for removal of Acid Red 17 (AR 17) dye from aqueous solutions. The surfactant-modified FE and FE were characterized by a Fourier transform infrared spectrometer, thermogravimetric analyzer and scanning electron microscope. Batch adsorption experiments were carried out as a function of contact time, pH, initial concentration of AR 17 and adsorbent dosage. About 99.1% adsorption efficiency was achieved within 60 min at adsorbent dose of 0.1 g for initial dye concentration of 1,000 mg L−1 at pH 10. The adsorption data were well fitted with the Dubinin–Radushkevich isotherm model implying physisorption as the major phenomenon for adsorption. The kinetic data were analyzed using four kinetic equations: pseudo-first-order, pseudo-second-order, intraparticle diffusion and Elovich equations. The rates of adsorption confirmed the pseudo-second-order kinetics with good correlation value (R2 = 0.999). The results indicate that the modified adsorbent can effectively be used for the removal of AR 17 from wastewater with high absorption capacity of 2164.61 mg g−1.

The hybrid nanocomposite was prepared by in situ intercalative polymerization of acrylamide in a fine dispersion of the sugarcane bagasse, chitin and fuller's earth by microwave irradiation. The product was very efficient as an adsorbent for metal ions and organic dye. It was mechanically stable in wet condition, resistant to fast microbial attack and released no leachates.

In this research, we studied improvement of mechanical properties of dimethacrylate-silica based dental composites by addition of Fuller's Earth (FE) clay. Three composites were made as base compounds consisting of 68, 58, and 48 wt % resin and 31, 41, and 51 wt % silica, respectively. Afterward, the composites were modified by adding FE. Mechanical properties including flexural strength, flexural modulus, work-of-fracture, fracture toughness, and microhardness were measured. Clay particles and fracture surface of composites consisting of 51 wt % silica (with and without FE) were examined by SEM. Measured results showed that flexural strength, work-of-fracture, flexural modulus, and microhardness of all composites increased by including FE nanofibers. Fracture toughness except for composite including 51 wt % silica had similar variations. It seems that locating FE nanofibers in weak resin region among silica particles leads to strengthening mechanisms, such as bridging and crack deflection, which cause improvement in mechanical properties. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.

A number of methods have been reported in the literature for the development of latent fingermarks on different surfaces. This paper reports a new and simple powdering method which is non-toxic and has been employed on different substrates successfully for the development and visualization of latent fingermarks up to the time period of 6 days in varying temperature conditions. In this investigation a less expensive, simple and easily available fuller’s earth (Multani Mitti) powder has been used to decipher the latent fingermarks on different substrates namely black cardboard box, clear glass, coverslip box, steel surface, laminated wooden sheet, clear plastic, colored plastic bag and surface of highlighter pen. It is observed that it gives very clear results on majority of substrates and can be successfully used for the development and visualization of latent fingermarks.

This study aimed at developing innovative systems for skin decontamination. Pickering emulsions, i.e. solid-stabilized emulsions, containing silica (S-PE) or Fuller's earth (FE-PE) were formulated. Their efficiency for skin decontamination was evaluated, in vitro, 45min after an exposure to VX, one of the most highly toxic chemical warfare agents. Pickering emulsions were compared to FE (FE-W) and silica (S-W) aqueous suspensions. PE containing an oil with a similar hydrophobicity to VX should promote its extraction. All the formulations reduced significantly the amount of VX quantified on and into the skin compared to the control. Wiping the skin surface with a pad already allowed removing more than half of VX. FE-W was the less efficient (85% of VX removed). The other formulations (FE-PE, S-PE and S-W) resulted in more than 90% of the quantity of VX removed. The charge of particles was the most influential factor. The low pH of formulations containing silica favored electrostatic interactions of VX with particles explaining the better elimination from the skin surface. Formulations containing FE had basic pH, and weak interactions with VX did not improve the skin decontamination. However, these low interactions between VX and FE promote the transfer of VX into the oil droplets in the FE-PE.

A simple, inexpensive and fast method for immobilizing α-amylase from mung bean (Vigna radiata) on Fuller’s earth was developed. For best immobilization (81% activity) the conditions were optimized with activation pH of 5.5 and 350 mg of Fuller’s earth with 6 mg/ml of protein. The optimum pH was slightly shifted towards alkaline side from 5.5 to 5.7, whereas the optimum temperature (65°C) remained unchanged. There was no significant change in Michaelis constant (K m), however, maximum velocity (V max) decreased by four fold upon immobilization. The immobilized enzyme showed an increase in half-life (60 days) and approximately 75% activity remained after five reuses. There was practically no leaching of enzyme from the adsorbent over a period of 20 days. α-Amylase immobilization has potential applications in food, cosmetics, biomedical, and pharmaceuticals industries.

Bench-scale batch experiments were performed to investigate the feasibility of using different types of clay minerals (bentonite, fuller's earth, and biotite) with zero-valent iron for their potential utility in enhancing nitrate reduction and ammonium control. Kinetics experiments performed with deionized water (DW) and groundwater (GW) revealed nitrate reduction by Fe(0) proceeded at significantly faster rate in GW than in DW, and such a difference was attributed to the formation of green rust in GW. The amendment of the minerals at the dose of 25 g L(-1) in Fe(0) reaction in GW resulted in approximately 41%, 43%, and 33% more removal of nitrate in 64 h reaction for bentonite, fuller's earth, and biotite, respectively, compared to Fe(0) alone reaction. The presumed role of the minerals in the rate enhancement was to provide sites for the formation of surface bound green rust. Bentonite and fuller's earth also effectively removed ammonium produced from nitrate reduction by adsorption, with the removal efficiencies significantly increased with the increase in mineral dose above 5:1 Fe(0) to mineral mass ratio. Such a removal of ammonium was not observed for biotite, presumably due to its lack of swelling property. Equilibrium adsorption experiments indicated bentonite and fuller's earth had maximum ammonium adsorption capacity of 5.6 and 2.1 mg g(-1), respectively.

Using the hairless mouse screening model presented in the companion paper1 the aim of this study was to assess two skin decontaminating systems: Fuller’s earth (FE) and Reactive Skin Decontamination Lotion (RSDL) against two extremely toxic chemical warfare agents that represent a special percutaneous hazard, sulphur mustard (SM) and O-ethyl-S-(2[di-isopropylamino]ethyl)methyl-phosphonothioate (VX). Five minutes after being exposed on the back to either 2 µL of neat sulphur mustard or 50 µg.kg-1 of diluted VX, mice were decontaminated. Both systems were able to reduce blisters 3 days after SM exposure. However, RSDL was found to be more efficient than FE in reducing the necrosis of the epidermis and erosion. In the case of VX exposure, RSDL, whatever the ratio of decontaminant to toxicant used (RSDL 10, 20, 50), was not able to sufficiently prevent the inhibition of plasma cholinesterases taken as a surrogate marker of exposure and toxicity. Only FE reduced significantly the ChE inhibition. Some of these observations are different from our previous results obtained in domestic swine and these changes are thus discussed in the perspective of using SKH-1 hairless mice for the initial in vivo screening of decontaminants.

Cu(II)-exchanged fuller's earth was prepared by ion-exchanging Ca2+ ions which are present within the interlayer of fuller's earth with Cu(II)ions by the solution-phase ion-exchange process. Pyrrole was introduced into Cu(II)-exchanged fuller's earth to spontaneously polymerize to within the interlayer to result in a nanocomposite of Cu(I)–polypyrrole–fuller's earth where both Cu(I) and polypyrrole occupy within the interlayer spaces of fuller's earth. The nanomaterial [Cu(I)–PPY–FE] has been fully characterized with X-ray diffraction studies, FTIR spectroscopy, DC polarisation test with both blocking stainless steel and non-blocking copper electrodes. The material is found to be a mixed conductor whose ionic mobility is 1.5 times faster than electronic mobility. DC polarisation studies also clearly revealed that the mobile ionic species in this material to be cuprous ions. AC impedance studies have been carried out with blocking stainless steel electrodes at different applied potentials. The necessary theoretical background to explain AC impedance results is also provided and the results obtained agree very well with the corresponding data obtained by other mutually independent methods. The electronic conductivities are around 3.0 × 10−4 S cm−1 and the ionic conductivities are around 9.0 × 10−3 S cm−1. The material may find applications in semi-fuel cells such as air–metal batteries.

The adsorption of dyes on to Fuller's earth and silica has been studied. A mass transfer model has been developed to describe the adsorption process based on external mass transfer and internal pore diffusion. Theoretical concentration decay curves have been predicted using the model and compared with experimental decay curves.

Fullers earth beads and cylinders were prepared using chitosan and sodium silicate as binders, respectively, for removal of cesium ion from aqueous solutions. The cost of the adsorbent is expected to be significantly lower as the raw materials are low cost materials and readily available. The adsorbents were characterized by SEM, EDS, and x‐ray microanalysis. Adsorption capacity of the beads was evaluated under both batch and dynamic conditions. The adsorption capacity for Fullers earth beads was found to be 26.3 mg/g of adsorbent at 293 K when the liquid phase concentration of cesium was 1000 mg/L. The adsorption capacity of Fullers earth cylinder was found to be higher than that of beads, however, it was concluded that the alkaline nature of the cylinder precipitated out cesium increasing its capacity. The capacity of Fullers earth beads decreased by almost 62% when 1 mol/L NaCl and 2.25 mmol/L of strontium were present in the solution. The Freundlich, the Langmuir isotherm equations, and a mod...

A series of polyaniline-Fuller's Earth (PANI-FE) nanocomposites were prepared by the successive intercalation of anilinium ions followed by polymerisation within the interlayer spaces of Fuller's Earth (a type of calcium montmorillonite). The first member in the series is prepared by exchanging the calcium ions in Fuller's Earth for ammonium ions and subsequently for anilinium ions and polymerising the latter using an externally introduced oxidant. The emeraldine salt form of polyaniline formed is then neutralised with ammonium hydroxide and more anilinium ions are exchanged for ammonium ions and polymerised to get the second member. In this manner, by making use the unique chemistry of clay and polyniline, four members of PANI-FE are prepared. In the last member, the negative layer charges of Fuller's Earth is completely neutralised by the positive charges of the polymer. The extent of polymer loading in each stage, the effect polymer has on the host structure and the electronic and ionic components of the conductivities of the new PANI-FE nanocomposites are investigated. The Fe(III) sites in FE are capable of spontaneously polymerising aniline within its intergalleries. The extent of spontaneous polymerisation is limited by the amount of Fe(III) present in the FE. The deliberate polymerisation of remaining anilinium ions by externally introduced oxidant results in highly conductive emeraldine salt-FE (EMS-FE) nanocomposites. The FE host accommodates higher amount of emeraldine salt and the repetitive insertions of the polymer could be done four times for complete layer charge neutralisation whereas with Bentonite the layer charge saturation takes place with three successive insertions. The new EMS-FE nanocomposites exhibit more than order of magnitude greater tuneable ionic and electronic conductivities compared to those of the same polymer incorporated in Bentonite.

The objective of this work was to prepare modified adsorbents from fuller's earth (FE) by acid and alkali treatment for enhancement cationic dye adsorption. Toluidine blue (TB) was selected as adsorbate for evaluating the adsorption performance of fuller's earth samples, which was affected significantly by acid and alkali modification. The adsorption of TB was studied by visible spectra. The absorption band of the monomer at low loading of TB in FE suspension with respect to its maximum in aqueous solution is red-shifted, which is related to accessibility of dye interlamellar space in the presence of positively charged surface sites. Since all surfaces are negatively charged under experimental conditions, this effect has not been observed in acid- and alkali-treated FE suspensions. It was seen that the adsorption capacity of alkali-treated surface (FEAl) for TB was higher than these of acid-treated adsorbent (FEAc) and FE. Scanning electron micrographs (SEM) and X-ray diffraction (XRD) and fluorescence (XRF) spectra were applied to analyze the structure of the raw and modified FE samples. Absence of any identifiable amount of a crystalline compound in the solid reaction products after acid treatment was confirmed by XRD and SEM, whereas the crystalline form of FEAl was preserved. Experimental data for high-concentration regions were well described by Freundlich and Langmuir adsorption equations. The thermodynamic parameters were estimated for FE, FEAc, and FEAl by using temperature dependence of adsorption equilibrium constants.

The adsorption of polyvinyl alcohol (PVA) onto Fuller's earth surfaces has been studied at fixed pH (4.8) and ionic strength of the medium. The adsorption isotherm obtained resembles with LIII type of isotherm, which indicates that multilayer formation of polymer chains begins after a certain time period when the monolayer formation is complete. The study of concentration effect and kinetics of adsorption process enabled in evaluating various adsorption and kinetic parameters such as the adsorption coefficient, modified Freundlich adsorption isotherm constants, distribution coefficient and rate constants for adsorption and desorption. A plausible mechanism of adsorption process was suggested according to which the adsorption was predominantly due to the formation of hydrogen bonds between the OH groups of PVA and aluminols, silanols and carboxylate ions of the organic matter of the Fuller's earth. The proposed mechanism was further confirmed by the IR spectral analysis of native and PVA-adsorbed clay. The adsorption was appreciably affected by the pH, presence of salts, organic solvents, solid to liquid ratio and temperature of the adsorption medium. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibb's free energy, enthalpy and entropy. The results obtained in the study helped in formulating a mechanism of interaction between PVA and Fuller's earth surfaces.

The adsorption behavior of methylene blue (MB) on four fuller's earth (FE) samples of varying compositions was investigated using a spectrophotometric technique to obtain information on the color removal. The distribution coefficient (K(D)) increased with an increase in the initial concentration (C(0)) of the dye, attained a maximum value, and decreased again at higher initial concentrations. Dye solutions became colorless for a C(0) value corresponding to maximum K(D). A progressively increased flocculation behavior in the clay suspensions was observed and the maximum value of K(D) corresponds to optimum flocculation of the clay. The K(D) values were found to decrease exponentially after of the solution again became colored while the amount adsorbed increased with an increase in the initial concentration of MB. Only adsorption data obtained for this region could be defined by adsorption isotherm equations. The shifts of the C(0) values corresponding to K(D)(max) toward higher concentrations were correlated with the composition of FE samples by using XRF, XRD patterns, and SEM images. The influence of temperature on MB adsorption was also studied and thermodynamic parameters were calculated.

An active shallow translational landslide in the Fuller's Earth Formation at Soper's Wood, Bath has been investigated, including engineering geological mapping, installation of standpipes/inclinometers and the geochemical analysis of groundwaters. Survey stations were established on the 4 to 21 degree east-facing slope. Monitoring undertaken between January and July 1994 records varying rates of movement for different parts of the slip, with maximum displacements of 2.8 m horizontally and 1.1 m vertically. There was a distinct correlation between movement and rainfall/groundwater levels and significant variation in the groundwater elevations at different positions within the landslide, emphasising the importance of obtaining sufficient standpipe piezometer data and the danger of generalising from too few groundwater monitoring points. The paper reports chemical analyses of groundwaters. It is postulated that the residual shear strength of failure surfaces will vary seasonally due to crystal precipitation/dissolution and physico-chemical effects.

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The adsorption of poly(vinylpyrrolidone) (PVP) onto Fuller's earth surface was studied at fixed pH (4.2) and room temperature (27 ± 0.2°C). The kinetics of the adsorption process was monitored and various adsorption and kinetic parameters such as the adsorption coefficient, the rate constants for adsorption and desorption, the diffusion constant, and the penetration constant were evaluated. The effects of various experimental factors such as the pH and the presence of inorganic and organic anions or aliphatic alcohols were also studied on the adsorbed amounts of PVP. The role of temperature was also investigated and various thermodynamic parameters such as the standard Gibb's free energy, enthalpy, and entropy were also evaluated.

Isothermal thermogravimetric experiments have been carried out to determine the reaction kinetics of the dehydration processes in fuller's earth, a natural Ca-montmorillonite. Dehydration in swelling clays is a complex reaction, and analysis of the thermogravimetric data using empirical rate equations and time-transformation analysis reveals that the nature of the rate controlling mechanism is dependent upon both the temperature regime of the sample as well as the extent of reaction. For fuller's earth, we find that the dehydration kinetics are dominated by a nucleation and growth mechanism at low temperatures and fractions transformed (stage I), but above 90 °C the last stages of the reaction are diffusion controlled (stage II). The activation energy for dehydration during stage I is around 35 kJ · mol−1, whereas the removal of water during stage II requires an activation energy of around 50 kJ · mol−1. These two stages of dehydration are associated with primary collapse of the interlayer (stage I) and movement of water that is hydrated to cations within the interlayer (stage II).

The paper reports analysis of a block sample taken from a trial pit, hand dug across the shear surface of an active landslide in the south Cotswolds. The slide is located on the Upper Fuller's Earth, some 50m downslope of the overlying Great Oolite limestone, the weathering of which has produced ooliths and gravel-sized fragments which are incorporated within the slipped mass. Sampling at 5 mm intervals confirmed the inverse relationship between the natural moisture content and calcite content. In order to assess the significance of changes in moisture content in the fine fraction, the influence of the non-sorptive calcite was removed and a normalized moisture content profile established. Examination of the lower shear surface using scanning electron microscopy confirmed the parallel orientation of the clay minerals for a thickness of some 1 μm. This thin veneer extended over areas of granular material, highlighting the importance of obtaining representative samples when shear strength assessment is undertaken. Le papier rend compte de 1'analyse d'un échantillon de bloc prélevé dans un pmts d'exploration creusée à la main à travers la surface de cisaillement d'un glissement de terrain actif dans le sud des Cotswolds. Le glissement est situé sur la terre à foulon supérieure, é quelque 50 m en contrebas du calcaire oolithique (Great Oolite) sus-jacent; dont l'altération a produit des oolithes et des fragments de la taille de gravillons incorporés dans la masse glissée. Les prélèvements d'échantillons, à intervalles de 5 mm, ont confirmé la relation inversement pro-portionelle entre la teneur en eau naturelle et la teneur en calcite. Pour pouvoir évaluer l'importance des changements de la teneur en eau dans la fraction fine, on a éliminé l'influence de la calcite non adsorbante et établi un profil de teneur en eau normalisé. L'examen de la surface de cisaillement inférieure par microscopie électronique à balayage, a confirmé l'orientation paralléle des minéraux d'argile sur une épaisseur de quelque 1 μm. Cette fine couche s'étendait sur les zones de matériaux granulaires, soulignant ainsi l'importance de l'obtention d'échantillons représentatifs lorsqu'on étudie la résistance au cisaillement.

Samples of Egyptian bentonitic sediments, representing Gabal Hamdal (Miocene) of Abu-Zeneima locality, were evaluated by different techniques for some applications such as bleaching, refining of oils and drilling mud. Mineralogically the samples were characterized as low grade of Ca–Mg smectite. The dominant gangue mineral is calcite with accessory amounts of kaolinite, quartz, feldspar and dolomite. Characterization of these samples indicated that the clay response for Na-exchange was poor while their hydration, plastic and rheological properties were inferior to those of commercial bentonites. The samples were processed by crushing, attrition scrubbing followed by hydrocycloning to give pre-concentrates which were leached with diluted HCl. Application of such simple flowsheet effectively removed the majority of the associated calcite, dolomite, feldspar and quartz. These concentrates were further refined by a series of acid and alkaline treatments prior to their evaluation as industrial bentonites. The mineralogy, chemical analysis and physical properties of final concentrates and their activated products successfully match the required specifications for many industrial processes. The bentonite concentrates after alkaline activation are suitable for drilling muds while the products of acid activation can be used as bleaching clay. Cost–benefit analysis of the suggested flowsheet, of beneficiation and activation, proved the economic viability of such processes. Utilization of these clays, after their upgrading and activation, can represent a value-added to the Egyptian economy by preventing the importation of high quality activated clays.