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In this work, a composite material for the adsorption removal of thiophenic sulfur compounds (TSCs) was prepared by loading Cu2O onto palygorskite using a simple and low‐cost impregnation method and characterized for its structure and morphology. The addition of Cu2O did not change palygorskite's structure, and the Cu+ was evenly dispersed in the palygorskite fibers. The palygorskite provided the adsorptive active centers Cu+ efficient surface and pore structure to increase the sulfur removal performance of palygorskite. The optimum desulfurization process conditions of the Cu2O/palygorskite were obtained experimentally and by response surface methodology. With solid/liquid mass ratio of 1/100 and temperature of 30°C, the maximum static adsorption capacity of the Cu2O/palygorskite in model oil, which was composed of n‐octane and a single TSC at 400 mg S/L, showed an increase of 639% for thiophene, 543% for benzothiophene, and 563% for dibenzothiophene compared to palygorskite alone. In addition, the pseudo‐second‐order kinetic and Langmuir isotherm model exhibited the most fitting results for thiophene adsorbing on the composite, indicating that chemisorption on a monolayer basis plays a key role in the adsorption process. To sum up, these results suggest the composite has some potential in the field of adsorption‐desulfurization materials. [ABSTRACT FROM AUTHOR]

Potassium behavior in calcareous soils are very complex and are affected by several factors, such as the content of carbonates and soil heating. In the present research, the comparison of four calcareous soils with varying amounts of carbonates, different mineralogy, and texture (collected from Fars province, southern Iran) was compared to analyze the content of K species, K release by solutions of 0.01 M CaCl2 and 1% wood vinegar, and K re-fixation. The study also investigated the impact of heating K-depleted soils to 100°C on the secondary release and re-fixation of K. The results showed that the studied soils contained 3–60% carbonates, 14–53% clay, and a relatively similar mineral composition: smectite, illite, chlorite, palygorskite (in dry areas), and vermiculite (in humid areas). Wood vinegar extracted more K from soils with less carbonates than CaCl2, while this difference was not significant for Fluvisols, which contains about 60% carbonates. Mollic Vertisols with low carbonate content (about 3%) and high levels of clay and smectite released less K in the initial phase. However, K release by this soil decreased less in the second phase, indicating the higher buffering capacity of Mollic Vertisols in providing soluble K. Heating the soil increased the secondary release of K, but decreased the amount of K re-fixation in soils treated with CaCl2. Generally, Mollic Vertisols fixed more K than other soils. In addition, the type of extractant had no effect on the content of K fixation in the studied soils except Mollic Vertisols. However, wood vinegar reduced the K fixation content in Mollic Vertisols compared to CaCl2. In general, it can be concluded that wood vinegar can provide more K to the plants without dissolving K-bearing minerals compared to CaCl2. In addition, soil heating can influence the process of K release and fixation in K-depleted soils. [ABSTRACT FROM AUTHOR]

In order to study the effect of support on the antibacterial activity of ZnO nanoparticles formed in the bioinspired process, a series of palygorskite (Pal) supported ZnO nanocomposites (ZnO/Pal) were fabricated using licorice extract and the antibacterial actions related to the structure of loaded ZnO nanocomposites was elucidated. The samples were characterized by the means of UV–vis, XRD, TEM, FTIR, TG and XPS, and the antibacterial properties were determined by the agar disk diffusion assay and colony counting assay. The structural analysis revealed that pure ZnO nanoparticles with average grain diameter of about 11 nm were formed in the green bioinspired process and anchored on the surface of Pal nanorods. And with Pal amount decreasing (ZnO loading increased from 10 % to 40 %), the ZnO NPs aggregated intensify and promoted the assembling of ZnO/Pal nanorods into bigger clusters, and four kinds of ZnO/Pal with different morphologies were formed. Among them, 20 % loading of ZnO/Pal showed antibacterial activity comparable to that of 30 % and better than that of 40 %, because ZnO nanoparticles in 20 % ZnO/Pal are monodispersed on Pal nanorods that maintained full exposure and high activity of ZnO NPs as well as better killing efficiency than those with clustered ZnO NPs. The mechanism analysis demonstrated that the bacteria-adsorbed capacity of Pal and the enhanced contact of small ZnO NPs with bacterial cells leading to intensified membrane-damage and intracellular metabolic imbalance are the main bactericidal actions of ZnO/Pal nanocomposites. This study first gave insight into the structure-related antibacterial behavior of ZnO/Pal nanocomposites, and provides an improved green way to design efficient clay-supported ZnO antibacterial nanomaterials. [ABSTRACT FROM AUTHOR]

In the northern part of the Niğde (Central Anatolian) Quaternary Bor Basin, stratigraphic sections P1 and P2 were sampled, reaching depths of 11 m and 25 m. The samples were analyzed with thin-section, XRD, and chemical analyses (ICP-MS) to determine their chemical and mineralogical properties. In the study area, partially lithified volcano-sedimentary rocks comprised paleosol, calcrete, gravel, sand, silt, mud, clay, and volcanoclastics such as pumice fall-out. Grain size analyses from the Zengen (P1) and Altunhisar (P2) regions showed very poor sorting and strong positive skewness. The Zengen-area (P1) samples contained rock fragments, calcite, quartz, opal-CT, feldspar, amphibole, pyroxene, biotite, and clay minerals such as smectite, chlorite, illite, palygorskite, and sepiolite. In calcrete zones, however, the amounts of CaO increased, whereas significant decreases in the amounts of SiO2 were observed. Therefore, a negative correlation between SiO2 and CaO was observed. The vertical distributions and behaviors of trace elements in the Zengen-area profile showed variation with the different levels of the P1 section. It is thought that in the Bor Plain, after 17,000 years ago, no lacustrine phase reached a level above the periglacial lake level in the region, reaching this level with the melting of the ice sheets in the area. During the late glacial period, shallow freshwater lacustrine phases and paleosols were identified from 12,500 to 11,000 yr BP in the basin. [ABSTRACT FROM AUTHOR]

Linear low‐density polyethylene (LLDPE) is a polyolefin known for its superior low‐temperature heat seal ability, low‐temperature tolerance, and bag‐tear resistance which are important features for the polymeric packaging sector. In this work, to improve the mechanical properties and expand the range of applications of LLDPE, the microfibrillar clay mineral palygorskite (PAL) was added. However, the use of PAL as a reinforcing agent for polymers depends on its purification process to extract accessory minerals such as calcite, dolomite, and quartz. In addition to this purification process, two surface modifications were used on the purified PAL (PALp) to improve interactions with LLDPE: silanization with aminosilane (PALs) and organophilization by incorporating an organic compound (PALo). The PAL were characterized according to their morphological properties using transmission electron microscopy (TEM), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT‐IR). The films of LLDPE/PAL, with varying levels (1, 3, and 5 wt%) and types of PAL (raw PAL, PALp, PALs, and PALo), were prepared by an extrusion process, and films were prepared by compression molding, without preferred orientation. The films were characterized by rheological analyses, tensile tests, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and water vapor permeability. Incorporating modified PAL was significant in enhancing the mechanical properties of the nanocomposites. LLDPE/PALs with the addition of 3 wt% PALs showed a 14% increase in elastic modulus (281.08 ± 8.25 MPa) compared to the nanocomposite with 3 wt% of raw PAL (243.43 ± 15.01 MPa). Highlights: The PAL is a clay mineral with a fibrous morphology and has a low cost.The technique to purify PAL is a quick, simple, and inexpensive technique.Comparison between of two technique surface modification of PAL.The effectiveness of modifications of PAL was confirmed in LLDPE films.The surface modification with silanization was more effective. [ABSTRACT FROM AUTHOR]

The removal of dyes from effluents of textile industries represents a technological challenge, due to their significant environmental impact. The application of halloysite (Hal) and palygorskite (Pal) clay minerals as adsorbents for the removal of Congo red (CR) and methylene blue (MB) was evaluated in this work. The materials were applied both in natural and acid-treated forms, and characterized by XRD, XPS, SEM–EDS, FTIR, and N2 adsorption–desorption isotherm techniques to identify their properties and main active sites. The adsorbents showed potential to remove CR (> 98%) and MB (> 85%) within 180 min, using 0.3 g adsorbent and initial dye concentration of 250 mg L−1. Semi-empirical quantum mechanical calculations (SQM) confirmed the interaction mechanism between dyes and the adsorbents via chemisorption (− 69.0 kcal mol−1 < Eads < − 28.8 kcal mol−1), which was further observed experimentally due to the high fit of adsorption data to pseudo-second order kinetic model (R2 > 0.99) and Langmuir isotherm (R2 > 0.98). The use of Pal and Hal to remove dyes was proven to be economically and environmentally viable for industrial application. [ABSTRACT FROM AUTHOR]

In this research, a pesticide-fertilizer combination (PFC) was fabricated using chlorantraniliprole and biochar. The PFC had a spherical shape, smooth surface, uniform particles, relatively dense structure and good compression resistance. The adsorption propertie of biochar to chlorantraniliprole was investigated. During the preparation of pelleted granules, the types and concentrations of core fillers and adhesives were screened and optimized. Besides, the safety to maize and effectiveness against fall armyworms of PFC had been investigated. Meanwhile, The PFC could promoted growth of maize significantly and control fall armyworm effectively. This work provides a promising approach to slow the release of chlorantraniliprole, which has a potential application to enhance the pesticides efficiency.

Nanofibrous clay minerals, specifically palygorskite (Pal) and sepiolite (Sep), have been becoming a new generation of rheological additives for drilling fluid systems due to their unique nanostructure, high performance, environmentally benign nature, and cost-effectiveness. These nanoclay minerals exhibit excellent colloidal and rheological properties in aqueous systems, even in saline and high-temperature environments. Although Pal and Sep have been employed as auxiliary rheological additives in a few cases to enhance the salt resistance of conventional water-based drilling fluids (WBDFs), these two clay minerals have not yet been used on a large scale due to a lack of understanding of their structures and properties, as well as the control of their performance. This paper presents a comprehensive review of the clay mineralogy, colloidal chemistry, rheological behaviors, and filtration properties of nanofibrous clay minerals in WBDFs, with critical comments. It also discusses the challenges and prospects for further research. This review provides new insights into fundamental and applied studies of nanofibrous clay minerals and helps promote the large-scale application of nanofibrous clay products in drilling fluids. [ABSTRACT FROM AUTHOR]

Ciprofloxacin, a second-generation fluoroquinolone, is widely used in human and veterinary medicine. However, it is known for its environmental persistence and ability to promote bacterial resistance, causing genotoxic impacts and chronic toxicity in various aquatic life forms. Adsorption is an effective technique for water treatment, removing multiple organic molecules, even in minimal concentrations. Hybrid materials based on fibrous clay minerals, such as palygorskite, are promising for environmental remediation, significantly when modified with oxides to improve their adsorption properties. This work prepared and characterized a CeO2/palygorskite hybrid material using various physicochemical techniques (XRD, FTIR, BET, SEM), which indicated the formation of the heterostructure material with interesting textural properties. This CeO2/palygorskite was evaluated as an adsorbent of the antibiotic drug ciprofloxacin. The influence of pH (3, 7, and 9) and ciprofloxacin concentration (6, 8, 10, and 14 ppm) on adsorption were studied, using pseudo-first- and pseudo-second-order kinetic models. The pseudo-second-order model showed the best fit (R2 > 0.99) and the lowest squared error (SSE), indicating chemisorption. The Langmuir, Freundlich, and Temkin isotherms were applied to the experimental data, where the Langmuir model had the best fit, indicating monolayer adsorption with a maximum capacity of 15 mg·g−1. Post-adsorption characterization by FTIR confirmed the structural stability of the material, highlighting its promising application in environmental remediation due to its high concentration of adsorbents. [ABSTRACT FROM AUTHOR]

Tayammum is a dry purifying method that uses earthen materials, mostly clay. The technique is applied when there is no access to water or in specific circumstances, such as when a person has susceptible skin on water. In tayammum, Islamic law describes clay as pure dust or soil used as a cleansing agent. Nevertheless, no scientific report examined the components of clay present in tayammum clay. Therefore, this study aimed to characterise and profile the mineral composition of tayammum clay, which is a commercially available product in Malaysia. Twelve commercial clay samples and one representative sample were analysed by ATR-FTIR spectroscopy in the range of 4000 to 600 cm-1. PCA exploratory analysis clearly demonstrated the differentiation of the tayammum clay product into seven groups according to its functional group. Following the FTIR analysis, the samples underwent examination using X-ray diffraction (XRD) and X-ray fluorescence (XRF) spectrometers further to identify the mineral and element composition of the clay, respectively. The XRD analysis indicated that there were possibly four types of mineral powder commonly distributed in the market for Tayammum purposes which are three types of clay: palygorskite, kaolinite, and phengite, and another one is zeolite-type: Na-heulandite. All four of them are common materials used for adsorbent and cleansing purposes. [ABSTRACT FROM AUTHOR]

Natural clay minerals are among the most versatile materials used in the biomedical field. Palygorskite has found various applications in this field, from the treatment of diarrheal diseases in the past to materials with antibacterial properties and platforms carrying bioactive compounds used in the treatment of diseases, cosmetic and healthcare products in the present. In this study, a possible delivery method of some bioactive asymmetric β-diketonic compounds is presented. Palygorskite modified with amphionic groups (P) and copper ions (PCu) was used as a platform to load bioactive curcumin derivatives (1 and 2). By varying the copper ions, the amounts of charged active compounds were monitored. Studies have shown that the hybrid materials resulting from the loading of 1 and 2 compounds on palygorskite with 30% copper ions (PCu30) can be used as delivery methods for these asymmetric curcumin derivatives, while palygorskite with 50% copper ions(PCu50) loaded with the same type of bioactive compounds has antibacterial properties. [ABSTRACT FROM AUTHOR]

The Eocene deposits belonging to the Khanguet Rheouis area, North–South Axis, Central Tunisia, consist of three lithological units deposited in a shallow water environment that is congruent to the Eocene regression. The middle unit represents a massive white dolomitic clay with gypsum intercalations that increase towards the top, containing significant amounts of palygorskite. SEM–EDX, XRD, and XRF analytical techniques were deployed to better understand the mineralogical and geochemical properties of the collected samples. Microtextural characteristics were analyzed using SEM and polarizing microscopy. Mineral spectral characteristics were determined by the Fourier Transform Infrared (FTIR) spectroscopy. The XRD analysis results show the predominance of dolomite with variable amounts of palygorskite and low quartz contents. Samples contained low concentrations of Nb, Th, Zr, Y, Rb, Zn, Cr, and V, which showed a positive correlation with the major oxides SiO2, Al2O3, Fe2O3, K2O, and TiO2, and a negative correlation with MgO and CaO, indicating that trace elements were exclusively retained in palygorskite rather than dolomite. SEM observations of palygorskite showed dense mats of short, interwoven fibers that bridged and filled the pore spaces between the dissolved dolomite. These textural characteristics suggest that the formation of palygorskite is post-dates dolomitization. Petrographic observations illustrate the existence of micro-tectonic structures such as stylolites and microcracks, playing an important role in the distribution of palygorskite. The obtained results are consistent with the hypothesis of a neoformed origin of palygorskite by direct chemical precipitation from solution, after partial dissolution of the dolomite. [ABSTRACT FROM AUTHOR]

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ABSTRACT: This experiment aimed to explore the protective effects of dietary palygorskite (Pal) supplementation on inflammatory responses and intestinal barrier function of broiler chickens challenged with Escherichia coli (E. coli). A 2 × 2 factorial arrangement was designed to assess the effects of Pal administration (0 or 5 g/kg of feed) and E. coli challenge (E. coli or bacterial culture medium) on broilers in a 21-d feeding trial. Birds were randomly assigned into one of the 4 groups, and each group had 8 replicates with ten birds each. The challenged chickens were orally gavaged with E. coli suspended in Luria-Bertani broth on 14 d of age, while unchallenged birds were administrated with an equivalent amount of culture medium. The sampling was performed at 21 d of age. Compared with the normal birds, an oral E. coli challenge reduced final body weight, and decreased feed intake, weight gain, and feed efficiency during the challenge period (P < 0.05). E. coli challenge promoted colonization of E. coli in cecal content and their translocation to internal organs (heart, liver, and spleen) (P < 0.05). E. coli infection also increased levels of pro-inflammatory cytokines in jejunum and ileum possibly through activating the toll-like receptor-4-mediated signaling pathway (P < 0.05). Moreover, E. coli administration increased intestinal mucosal permeability (higher serum D-lactate level and diamine oxidase activity, and lower intestinal mucosal disaccharidase activities), altered intestinal morphology, and downregulated the gene expression of intestinal tight junction proteins (P < 0.05). In contrast, Pal supplementation enhanced growth performance, inhibited colonization of E. coli, reduced intestinal inflammation, decreased intestinal permeability, restored intestinal morphology, and normalized the expression of genes responsible for inflammatory processes and maintenance of intestinal mucosal barrier (P < 0.05), and most of these beneficial effects resulting from Pal administration were independent of bacterial challenge. The results indicated dietary Pal incorporation was effective in improving growth performance and alleviating inflammation and intestinal mucosal barrier damage in broilers challenged with E. coli.

Abstract Herein, a practical ultra-high-performance concrete (UHPC) was created by adding two different shapes of steel fibers and curing them at ambient temperature using palygorskite-nanofiber (PN) as the modifier. The compressive strength, flexural strength, water absorption capacity, and porosity were analyzed to determine the effects of the steel fibers and PNs on the UHPC mechanical and physical properties. The steel fibers and PNs were found to improve these properties. The UHPC mechanical properties were outstanding at 1.5% fiber dosage, while physical properties were excellent at 1.0% fiber dosage. The mechanical and physical characteristics of UHPC were preferably at a PN dosage of 0.2% and the fiber dosage of 1.0%. The compressive and flexural strengths of straight-steel-fiber UHPC were 145.57 and 19.67 MPa, respectively, i.e., 42.0 and 109.4% higher than those of the reference specimens (i.e., those without fibers or PNs); the water absorption capacity and porosity decreased by 50.1 and 60.7%, respectively. The compressive and flexural strengths of hooked-end-steel-fiber UHPC were 18.3 and 96.0% higher than those of the reference specimens, respectively, and the water absorption capacity and porosity decreased by 43.2 and 29.8%, respectively. These results could provide vital information for the promotion and practical application of UHPC.

The influence of surface modification and some processing parameters on the palygorskite (Pal) dispersion and the mechanical, thermal and rheological properties of the resulting Nylon 6 nanocomposites was investigated. Natural Pal was surface modified with hexadecyl tributyl phosphonium and 3‐aminopropyl trimethoxysilane to produce organoclays with different surface energy values. Nylon 6/Pal nanocomposites were produced by twin screw extrusion and then injection molded, Pal loading was 2 wt. % in all the cases. A screw configuration was designed to impose different level of shear stresses to the nanocomposites during processing, and nanocomposites were extruded at two different screw speeds. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations indicated that Pal was dispersed differently depending mainly on the degree of shear stress and surface modification of Pal. The best tensile mechanical properties were achieved with Pal exhibiting the lowest surface energy value dispersed with the screw having high shear configuration. The fatigue life of nylon 6 improved with addition of Pal. The experimental results give some guidelines for producing Nylon 6/Pal nanocomposites with improved properties. [ABSTRACT FROM AUTHOR]

The present work studies the water absorption kinetics of polypropylene foams modified with palygorskite nanoclay. The polypropylene/palygorskite composites were prepared with a modular twin-screw extruder and then foamed in a conical twin-screw extruder. The mechanisms of water absorption kinetics of the polypropylene/palygorskite foams were analyzed using a multi-stage model to understand the influence of the clay concentration, nanoclay dispersion and foam cell morphology on the water absorption behaviour of the foams. The solid nanocomposites were characterized by transmission electron microscopy to measure the clay dispersion in the matrix. The nano-reinforced foams were characterized by optical microscopy to measure the cell size and by scanning electron microscopy to measure the size of the foam micropores. Water absorption, foam density and cell morphology were also measured. The nanoclay modifies the foam cellular structure, generating non-homogeneous and non-uniform open cells; these cells encompass micropores which facilitate water diffusion consequently the water absorption properties of the foams are modified. The different screw configurations used during the extrusion process of the composites yield polypropylene foams with different clay dispersion and consequently different foam cellular structure. [ABSTRACT FROM AUTHOR]

Although several reports are available on the distribution of Palygorskite in the soils of arid regions of Iran, there is not much information about the presence and abundance of this important fibrous clay mineral in the soils of Bushehr Province. This research was carried out: (1) to investigate the distribution of Palygorskite and other major associated clay minerals, and (2) to evaluate the relationship between the relative quantity of Palygorskite in clay-sized fraction and the most important soil properties in Dashtestan County, Bushehr Province. Five geomorphic surfaces including eroded rock outcrop, rock outcrop, dissected hill, alluvial fan, and alluvial plain were identified in the study area using Google Earth images and field observations. After sampling representative pedons, the clay mineralogy of two horizons from each pedon was determined. X-ray diffractograms and SEM images showed that in the studied soils, which were classified as either Aridisols or Entisols, Palygorskite was present in different quantities on all geomorphic surfaces. Moreover, Illite, Chlorite, Smectite, irregularly interstratified Chlorite/Illite, and Kaolinite were the other clay minerals that existed in the soils studied. The relative quantity of Palygorskite and Smectite was variable on different geomorphic surfaces. Regardless of the type of geomorphic surface, petrogypsic and gypsic horizons showed the highest quantity of Palygorskite as compared to other horizons which seems to be due to the suitable geochemical conditions of these horizons for the formation and stability of Palygorskite mineral. The higher correlation of Palygorskite content with gypsum, as compared to that with the carbonates, indicates the importance of gypsum in Palygorskite distribution in the soils of the study area. The findings also indicated that the amount of Palygorskite was positively correlated with soluble Mg/Ca ratio, pH, gypsum, and soluble Mg. These parameters appear to control the genesis and distribution of Palygorskite in the soils studied. In general, it is necessary to pay special attention to their clay mineralogy, especially the significant amount of Palygorskite to manage the soils of the study area and to reasonably predict their behavior. [ABSTRACT FROM AUTHOR]

The Zagros foreland basin is an important sedimentary archive for the tectonic and paleoclimatic evolution of the Zagros Mountains and the entire Neotethyan Arabia-Iran collision zone. By combining new geochemical high-resolution whole rock XRF data with clay mineralogy and soluble salt geochemistry we propose an evolution of the sedimentary environment in the Lurestan arc from the Serravallian to the early Pleistocene, closing a gap in understanding the complex exhumation history of the central Zagros mountain belt. An increase in ultramafic sedimentary input indicates a shift from provenance 1 to provenance 2 by ophiolite exhumation at ca.10 Ma in the Imbricated Zagros north of the Lurestan arc. Our data further indicates that the sedimentary environment of parts of the Lahbari Mb within the Lurestan arc represents a piedmont deposition of finegrained alluvial fans and siltstones with aeolian contribution deposited under hyper-arid climate conditions. These represent provenance shift 3 and were likely sourced from evaporites of the underlying Gachsaran Fm and fluvial deposits of the Lower Aghajari Mb (provenance 1 and provenance 2), uplifted by the Mountain Front Flexure at around 5.6 Ma. Combining XRF whole rock data with clay mineral data refines formation conditions of the clay minerals in the foreland basin such as palygorskite, which is revealed to be authigenic in origin in the Lower Aghajari Mb. as a function of varying Mg-content due to variations of erosion of the ultramafic and mafic rocks in the Imbricate Zagros belt. Palygorskite in the Lahbari Member is likely both inherited from the Neogene Gachsaran evaporites as well as of authigenic origin. [ABSTRACT FROM AUTHOR]

On-site hydrogen generation from ammonia decomposition is a promising technology to address the challenges of direct transportation and storage of hydrogen. The main problems with the existing support materials for ammonia decomposition catalysts are their high cost and time-consuming preparation process. In this work, ammonia decomposition catalysts consisting of in situ-formed nano-Ru particles supported on a naturally abundant mineral fiber, attapulgite (ATP), were proposed and studied. Also, 1 wt.% Ru was uniformly dispersed and anchored onto the surface of ATP fibers via the chemical method. We found that the calcination temperatures of the ATP support before the deposition of Ru resulted in little difference in catalytic performance, while the calcination temperatures of the 1Ru/ATP precursor were found to significantly influence the catalytic performance. The prepared 1 wt.% Ru/ATP catalyst (1Ru/ATP) without calcination achieved an ammonia conversion efficiency of 51% at 500 °C and nearly 100% at 600 °C, with the flow rate of NH3 being 10 sccm (standard cubic centimeter per minute). A 150 h continuous test at 600 °C showed that the 1Ru/ATP catalyst exhibited good stability with a degradation rate of about 0.01% h−1. The 1Ru/ATP catalyst was integrated with proton ceramic fuel cells (PCFCs). We reported that PCFCs at 650 °C offered 433 mW cm−2 under H2 fuel and 398 mW cm−2 under cracked NH3 fuel. The overall results suggest low-level Ru-loaded ATP could be an attractive, low-cost, and efficient ammonia decomposition catalyst for hydrogen production. [ABSTRACT FROM AUTHOR]

The aim of the present study was the direct comparison of two popular minerals, bauxite and palygorskite, as adsorbents for the removal of cephalexin (CPX) from aqueous solutions and the regeneration of the spent adsorbents through cold atmospheric plasma. Batch kinetics and isotherm studies were carried out to evaluate the effect of contact time, initial CPX concentration, adsorbent dosage, pH and temperature. The adsorbents were characterized by ATR-FTIR, N2 sorption, SEM and XRD, while several isotherm, kinetic and thermodynamic models were evaluated attempting to shed light on the adsorption mechanisms. CPX adsorption on both adsorbents was better described by Langmuir model, with an adsorption capacity of 112.36 mg/g for palygorskite and 11.79 mg/g for bauxite. Thermodynamics revealed the endothermic and the spontaneous character of the process, indicating chemisorption as the main adsorption mechanism for both adsorbents. The pseudo-second-order and the Elovich models fitted satisfactorily the adsorption onto bauxite, while adsorption onto palygorskite was well presented by Weber–Morris model, indicating that pore diffusion is also involved in the process. The adsorption capacity of both minerals decreased significantly after being used for several adsorption cycles and then almost completely recovered (regeneration efficiency was 99.6% and 98% for palygorskite and bauxite, respectively) inside a novel cold plasma microbubble reactor energized by high-voltage nanopulses, revealing the potential of these adsorbents to be reused. In addition to the regeneration of the adsorbents, the cold plasma completely eliminated the CPX transferred from the solid to the aqueous phase during the regeneration process. [ABSTRACT FROM AUTHOR]

Recently, heavy metal pollution in soil has been threatening human health and ecological security. Natural attapulgite suffers from low efficiency in the passivation of heavy metals present in soil. Herein, a simple one-step hydrothermal method was introduced to modify low-grade attapulgite by introducing exogenous Si2+/Mg2+/Ca2+ for the passivation of cadmium in soils. Results from field-emission scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy techniques showed that some attapulgite and associated minerals transformed into amorphous silicate particles with low crystallinity and were uniformly distributed on the attapulgite surface. Results from the toxic characteristic leaching procedure and CaCl2 extraction showed that the bioavailability and leaching toxicity of cadmium reduced considerably by the addition of modified attapulgite. Results from the European Community Bureau of Reference's sequential extraction method showed that the addition of modified attapulgite could promote the conversion of soil acid-exchangeable and reducible speciation cadmium into oxidizable and residual speciation cadmium. Moreover, results from pot experiments showed that the modified attapulgite could effectively reduce the adsorption of cadmium by rice and alleviate the inhibitory effect of cadmium on plant growth. In particular, the modified attapulgite exerted the best immobilization effect on cadmium when the Si2+:Mg2+:Ca2+ ratio was 2:1:2. The mechanisms of cadmium immobilization include electrostatic adsorption, coprecipitation, ion exchange, and surface functional group complexation. This study demonstrates the advantages of using low-grade attapulgite as a new material for the remediation of cadmium-contaminated soil and provides a reference for the development and application of environmentally friendly passivation agents. [ABSTRACT FROM AUTHOR]

This work focuses on the characterization of five palygorskite clays from the Brazilian state of Piaui and their feasibility as eco-friendly adsorbents for the removal of Fe3+ ions from aqueous solutions. For characterization, we applied the techniques of X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), size distribution measurements, density measurement by He pycnometry, superconducting quantum interference device (SQUID) magnetometry, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA/DTA), zeta potential measurement, hydrophobicity determination by contact angle, Brunauer–Emmett–Teller surface area analysis (BET technique) and atomic force microscopy (AFM). Batch experiments were performed in function of process parameters such as contact time and initial concentration of Fe3+. The natural palygorskites (Palys) had excellent performance for the removal of Fe3+ from aqueous solutions by adsorption (around 60 mg/g), and the Langmuir is supposedly the best model fitted the experimental data. [ABSTRACT FROM AUTHOR]

Palygorskite is a magnesium-rich aluminosilicate clay mineral with a unique chain-layered structure. This structure gives palygorskite a large specific surface area and interesting physical properties. Many researchers have investigated the applications of palygorskite in various fields, including heavy metal adsorption, petroleum and chemical industries, building materials, medicine and agriculture. In this study, molecular dynamics simulations were used to explore the heavy metal adsorption ability of palygorskite. The results showed that polyacrylic acid (PAA) had a heavy metal adsorption ability. In terms of the ability of the substrate to adsorb Pb2+, Ni2+ and Cr3+, palygorskite (attapulgite, ATP) was more effective than SiO2 or clay. Based on this study, the same phenomenon reported in the literature was confirmed, and it was demonstrated that molecular dynamics could properly simulate the filtration of heavy metal ions in water using novel materials. Moreover, H+ was found to play an essential role in assisting PAA/ATP in capturing heavy metal ions. Using this method, we were able to observe the details of heavy-ion adsorption.

This work focuses on the characterization of five palygorskite clays from the Brazilian state of Piaui and their feasibility as eco-friendly adsorbents for the removal of Fe3+ ions from aqueous solutions. For characterization, we applied the techniques of X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS), size distribution measurements, density measurement by He pycnometry, superconducting quantum interference device (SQUID) magnetometry, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA/DTA), zeta potential measurement, hydrophobicity determination by contact angle, Brunauer–Emmett–Teller surface area analysis (BET technique) and atomic force microscopy (AFM). Batch experiments were performed in function of process parameters such as contact time and initial concentration of Fe3+. The natural palygorskites (Palys) had excellent performance for the removal of Fe3+ from aqueous solutions by adsorption (around 60 mg/g), and the Langmuir is supposedly the best model fitted the experimental data.

The purpose of this experiment was to use a single-factor design to investigate the effects of different supplementation levels of plant essential oil/palygorskite composite (EPO-Pal) on growth performance, blood parameters, and intestinal morphology of broiler chicken. A total of 960 one-day-old chicks were randomly assigned into 4 treatments with 6 replicates of 40 chicks each. The broilers were fed the basal diet supplemented with 0, 500, 750, and 1000 mg/kg EPO-Pal for 42 days, respectively. The results showed that the 500 or 750 mg/kg groups significantly increased the body weight, average daily feed intake and average daily gain of the broilers at 28 and 42 days (p

The pollution problem resulting from advancements in science and technology is increasingly severe, particularly concerning organic pollution. Photocatalytic technology is considered one of the most effective methods for treating organic pollution due to its cost-effectiveness, simplicity of operation, high efficiency, and versatility. In this study, palygorskite was purified and extracted using techniques such as ultrasonication, high-speed stirring, centrifugation, and others. Molybdenum disulfide (MoS2) was synthesized in situ on the palygorskite surface through hydrothermal synthesis, resulting in palygorskite/MoS2 nanocomposites. The structure and apparent morphology of the palygorskite/MoS2 composites were analyzed using characterization methods such as transmission electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, and others. MoS2 interacted with the hydroxyl groups on the palygorskite surface through amino groups, leading to the dispersion of MoS2 nanosheets on the palygorskite surface, forming a unique nanoflower structure. To assess the photocatalytic degradation performance of palygorskite/MoS2 composites, Rhodamine B was employed as the target pollutant. Under conditions of a pH of 6, a reaction time of 170 min, and a solution concentration of 1500 mg/l, palygorskite/MoS2 composites achieved a Rhodamine B removal amount of 371.73 mg/g. Notably, these composites facilitated the degradation of Rhodamine B into intermediate chain-broken products. The findings of this study hold significant implications for the advancement of clay mineral-based photocatalytic composites and the effective removal of organic pollutants. [ABSTRACT FROM AUTHOR]

A highly efficient heterogeneous catalyst (Pd@Fun-PGS) is successful prepared by palladium immobilized on the surfaces of palygorskite via a simple method. After functionalization of the natural palygorskite under mild conditions, a large number of effective binding sites are produced, which perform high catalytic activity in water under mild conditions for a wide scope of Suzuki–Miyaura coupling reactions without phosphine ligand. The novel catalyst is characterized by FT-IR, XRD, XPS, SEM and TEM. It is worth noting that the efficient and stable catalyst could be easily reused for at least 8 times with inappreciable metal leaching. The catalyst system has potential applications in organic synthesis and is expected to further expand the utilization of clay in the catalytic field. [ABSTRACT FROM AUTHOR]

Particle size reduction by ultrasound is more favorable than conventional grinding due to its tendency to preserve the material's crystal structure. For palygorskite clay, the optimization was carried out using response surface methodology for the variables of sonication time, power, duty cycle, and clay loading. A 2FI model was fit to the dimensionless size number to navigate the design space of the model with an r-squared value of 0.9662. We found that the most optimal conditions for the size reduction were 45 min of sonication time, 110 W of sonication power, 90% duty cycle and 0.06 g/mL of clay loading. The loading and duty cycle terms had a positive effect on the particle size reduction, while an increase in power increased the particle size of the clay. The effect of time was found to be dependent on the values of the clay loading as well as the duty cycle. The XRD analysis of palygorskite clay for the untreated and treated samples indicated that ultrasound causes minimal changes to the crystal structure of the clay. The overall outcome of the study suggests that at optimal ultrasound conditions, particle size is reduced to ~ 1/16 times the initial value and the electric power input in the ultrasound generator takes an energy requirement of ~ 0.0124 kWh/g of solids processed for size reduction. [ABSTRACT FROM AUTHOR]

Palygorskite is a magnesium-rich aluminosilicate clay mineral with a unique chain-layered structure. This structure gives palygorskite a large specific surface area and interesting physical properties. Many researchers have investigated the applications of palygorskite in various fields, including heavy metal adsorption, petroleum and chemical industries, building materials, medicine and agriculture. In this study, molecular dynamics simulations were used to explore the heavy metal adsorption ability of palygorskite. The results showed that polyacrylic acid (PAA) had a heavy metal adsorption ability. In terms of the ability of the substrate to adsorb Pb2+, Ni2+ and Cr3+, palygorskite (attapulgite, ATP) was more effective than SiO2 or clay. Based on this study, the same phenomenon reported in the literature was confirmed, and it was demonstrated that molecular dynamics could properly simulate the filtration of heavy metal ions in water using novel materials. Moreover, H+ was found to play an essential role in assisting PAA/ATP in capturing heavy metal ions. Using this method, we were able to observe the details of heavy-ion adsorption. [ABSTRACT FROM AUTHOR]

The purpose of this experiment was to use a single-factor design to investigate the effects of different supplementation levels of plant essential oil/palygorskite composite (EPO-Pal) on growth performance, blood parameters, and intestinal morphology of broiler chicken. A total of 960 one-day-old chicks were randomly assigned into 4 treatments with 6 replicates of 40 chicks each. The broilers were fed the basal diet supplemented with 0, 500, 750, and 1000 mg/kg EPO-Pal for 42 days, respectively. The results showed that the 500 or 750 mg/kg groups significantly increased the body weight, average daily feed intake and average daily gain of the broilers at 28 and 42 days (p < 0.05). Additionally, as compared to the control group, the 1000 mg/kg EPO-Pal group exhibited higher levels of immunoglobulins-A, immunoglobulins-G, immunoglobulins-M, and high-density lipoprotein cholesterol while having lower levels of tumour necrosis factor-α (p < 0.05). The content of interleukin-2 and the villus height-to-crypt depth ratio were significantly increased in the 750 mg/kg EPO-Pal group (p < 0.05). Moreover, the activity of total antioxidant capacity and superoxide dismutase were significantly enhanced in the 500 mg/kg EPO-Pal group (p < 0.05). The results are very promising, and EPO-Pal can be considered as an additive to promote the growth by enhancing immunity, antioxidant activity, and improving the intestinal morphology of broiler chickens. Dietary supplementation of EPO-Pal improved the growth performance by increased average daily feed intake of broiler chickens. Dietary supplementation of EPO-Pal enhanced plasma antioxidation and immune response of broiler chickens. Dietary supplementation of EPO-Pal can postively affect the intestinal morphology of broiler chickens. [ABSTRACT FROM AUTHOR]

The retreat of the Dead Sea and the lowering of the base level in recent decades have led to the exposure of the littoral clay sediments on the shore, the occurrence of exposed mudflats and the development of ground subsidence along strips ('subsidence strips') and clustered sinkholes. Based on field observations and laboratory analyses, the present study characterizes the clayey sediments in the environment of the exposed mudflats on the western Dead Sea shore. The clayey sediments of the exposed mudflats ('mudflat sediments') consist of fine-grained laminated calcareous clays. The mineral composition of the bulk mudflat sediments consists of clay and carbonate minerals (calcite, aragonite and dolomite) with some quartz and feldspar, and frequently gypsum and halite. The clay mineral composition of these samples is smectitic illite–smectite and kaolinite with some discrete illite and palygorskite. The smectitic illite–smectite is randomly interstratified (1.7 nm illite–smectite type R = 0). Although the detrital smectitic illite–smectite in the mudflat sediments is situated in the saline environment of the Dead Sea shore, no significant illitization is observed in the depositional detrital clay. Subsidence strips with clustered sinkholes were formed in the exposed mudflats as part of the adjustment of the Dead Sea periphery to the lowering of the base level as a result of the retreat. The field observations in the studied area reveal that the subsiding of mudflat sediments in the formation of the subsidence strips usually involves mud sagging of wet clayey sediments in the subsurface and sediment collapse of dry clayey sediments near the surface. [ABSTRACT FROM AUTHOR]

Environmental pollution is an issue of particular concern, specifically when industrial waste products are not subjected to appropriate treatment. Among various industries in the agri-food sector, the brewing industry holds a significant position in this context, given that beer stands as the predominant choice of consumers. Brewery waste generates significant quantities of organic substances, along with ammonium nitrogen and phosphorus. Among the various methods for their treatment, adsorption has received substantial attention due to its cost-effectiveness and operational simplicity. The present study investigates the adsorption capacity of two materials, zeolite and palygorskite, for the removal of ammonium nitrogen and brewery waste, using columns and batches. Simultaneously, desorption and regeneration experiments were conducted, and the effect of pH on their effectiveness was also examined. To understand the adsorption mechanisms, isotherm and kinetic models have been estimated. The results of the experiments have demonstrated a marked adsorption efficiency of the adsorbent materials, surpassing 90%. In comparison, zeolite has exhibited a better adsorption capacity in the removal of ammonium nitrogen, while palygorskite has shown greater aptitude for phosphorus removal. The purpose of these experiments was to investigate the adsorption capacity of these two materials as a potential medium for brewery wastewater treatment (e.g., as part of adsorption filter, trickling filters, and constructed wetlands). [ABSTRACT FROM AUTHOR]

Parent material and topography are among the soil-forming factors that affect soil evolution by influencing different parameters. This study was conducted to compare the effect of marl and calcareous parent materials in different slope positions, including the summit, shoulder, foot-, and toe-slopes on soil clay mineralogy in the Karoon 3 Basin, east of Khuzestan Province. Four soil profiles in each of the two topo-sequences were dug. They were sampled based on their genetic horizons and some physical, chemical properties, and clay mineralogy were measured. The results showed that the type and abundance of clay minerals identified for both parent materials were more affected by topo-sequence position. The composition of minerals identified in the topo-sequence with marl parent materials included kaolinite, palygorskite, smectite, chlorite, mica, and quartz, and in the topo-sequence with calcareous parent materials, palygorskite, smectite, chlorite, mica minerals, and quartz, and most of the identified minerals were also observed in all positions in the C horizon. However, in marl parent materials kaolinite, and calcareous parent materials, smectite seems to have been formed pedogenically. The result of the association between Weaver and Beck indicated that most of the clay minerals are in the equilibrium of Palygorskite.

Removing phosphate from wastewater can help alleviate eutrophication. Therefore, in this study, lanthanum and magnesium were loaded onto the thermally modified palygorskite (PAL) using a coprecipitation method, and a composite material was prepared for phosphate recovery. In the pH range of 2–7, the material can effectively adsorb the phosphate. In the kinetic experiment, the material was able to rapidly adsorb phosphate within 4 h of the beginning of the reaction. The adsorption isotherm result of the material was in accordance with Freundlich isotherm model. When pH was 7, the theoretical maximum adsorption capacity was 20.4 mg P/g. When phosphate coexisted with CO32− and HCO3−, the adsorption was significantly inhibited. In the adsorption–desorption experiment, the material can be reused at least five times after elution with 1 mol/L of sodium hydroxide solution. The equilibrium adsorption capacity of the material for total phosphorus in piggery wastewater was 7.25 mg P/g, achieving a total phosphorus removal rate of 95.3%. The characterization of XRD, FT-IR and XPS suggested that phosphate was mainly exchanged with La–OH in the material, forming an amorphous LaPO4 complex. HIGHLIGHTS The LM-HPAL material was prepared by doping lanthanum and magnesium on palygorskite after high-temperature treatment.; The specific surface area of the LM-HPAL material increased to 98.2063 m2/g.; The LM-HPAL material can be regenerated through sodium hydroxide solution and can be reused at least five times.; The removal rate of total phosphorus in piggery wastewater by the LM-HPAL material reached 95.3%.;

Nanofibrous clay minerals, specifically palygorskite (Pal) and sepiolite (Sep), have been becoming a new generation of rheological additives for drilling fluid systems due to their unique nanostructure, high performance, environmentally benign nature, and cost-effectiveness. These nanoclay minerals exhibit excellent colloidal and rheological properties in aqueous systems, even in saline and high-temperature environments. Although Pal and Sep have been employed as auxiliary rheological additives in a few cases to enhance the salt resistance of conventional water-based drilling fluids (WBDFs), these two clay minerals have not yet been used on a large scale due to a lack of understanding of their structures and properties, as well as the control of their performance. This paper presents a comprehensive review of the clay mineralogy, colloidal chemistry, rheological behaviors, and filtration properties of nanofibrous clay minerals in WBDFs, with critical comments. It also discusses the challenges and prospects for further research. This review provides new insights into fundamental and applied studies of nanofibrous clay minerals and helps promote the large-scale application of nanofibrous clay products in drilling fluids.

Ciprofloxacin, a second-generation fluoroquinolone, is widely used in human and veterinary medicine. However, it is known for its environmental persistence and ability to promote bacterial resistance, causing genotoxic impacts and chronic toxicity in various aquatic life forms. Adsorption is an effective technique for water treatment, removing multiple organic molecules, even in minimal concentrations. Hybrid materials based on fibrous clay minerals, such as palygorskite, are promising for environmental remediation, significantly when modified with oxides to improve their adsorption properties. This work prepared and characterized a CeO2/palygorskite hybrid material using various physicochemical techniques (XRD, FTIR, BET, SEM), which indicated the formation of the heterostructure material with interesting textural properties. This CeO2/palygorskite was evaluated as an adsorbent of the antibiotic drug ciprofloxacin. The influence of pH (3, 7, and 9) and ciprofloxacin concentration (6, 8, 10, and 14 ppm) on adsorption were studied, using pseudo-first- and pseudo-second-order kinetic models. The pseudo-second-order model showed the best fit (R2 > 0.99) and the lowest squared error (SSE), indicating chemisorption. The Langmuir, Freundlich, and Temkin isotherms were applied to the experimental data, where the Langmuir model had the best fit, indicating monolayer adsorption with a maximum capacity of 15 mg·g−1. Post-adsorption characterization by FTIR confirmed the structural stability of the material, highlighting its promising application in environmental remediation due to its high concentration of adsorbents.

In this study, a new thermosensitive surface imprinted polymer based on palygorskite was successfully synthesised by a surface imprinting technique and used as an intelligent selective recognition adsorbent for the adsorption of Cu(II) ions from aqueous solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) measurements results demonstrated that Cu(II)-imprinted polymer was successfully synthesised. The separation and preconcentration characteristics of Cu(II)-imprinted polymer for Cu(II) were researched by batch and column procedures. optimal intelligent recognition temperature for adsorption is 35°C and intelligent identification and elution of Cu(II) can be achieved by adjusting the temperature. The maximum static adsorption capacity of the ion-imprinted and non-imprinted sorbents for Cu(II) was 35.55 and 9.78 mg g−1, respectively. The relative selectivity factor values (ar) of Cu(II)/Zn(II), Cu(II)/Ni(II), Cu(II)/Co(II) and Cu(II)/Pb(II) were 111.48, 85.37, 98.31 and 73.85 respectively, which were all greater than 1. The Cu(II)-imprinted polymer offered fast kinetics for the adsorption and desorption of Cu(II). Under the optimised conditions (pH-5, temperature-35°C, shaking time-15 min), a detection limit of 0.21 μg L−1 with a relative standard deviation (RSD) of 2.5% for Cu(II) was obtained. Based on Cu(II)-imprinted polymer packed columns, a highly selective pre-concentration method for Cu(II) was established. The accuracy of the method has been certified using national reference materials (GBW 08301). This method has also been successfully used for the determination of Cu (II) in locally collected water samples. [ABSTRACT FROM AUTHOR]

Palygorskite is a fibrous magnesium-rich clay mineral with a typical tunnel structure, and its adsorption properties make it an ideal adsorbent for broad applications. Thus, revealing the confinement effects on tunnel species can help in understanding its adsorption properties. Grand canonical Monte Carlo and molecular dynamics simulations were performed to analyze the effects of the crystal chemistry of palygorskite on the adsorption, occurrence, and mobility of tunnel water. Water adsorption isotherm, distribution models, and mobility were achieved from these simulations. Zeolitic water emerges into the tunnels even at a low relative humidity (RH) (such as 5%) and completely fills the tunnels as the RH increases to 10%. In neutral palygorskite, the influence of the octahedral type on water adsorption is not obvious, but the influence of tunnel cations is obvious. The occupation of Na+ ions in tunnels can reduce the maximum water amount and affect the spatial distribution of zeolitic water. The water distribution in tunnels can be described by a two-zeolitic water-site model for neutral palygorskite and a one-zeolitic water-site model for the charged one. The zeolitic water confined in the tunnel presents very low mobility, and the appearance of Na+ ions in the charged palygorskite further reduces the mobility of zeolitic water. Compared with other clay minerals, the much lower water mobility of palygorskite implies that it may have a more efficient fixation on foreign molecules or ions in environmental applications. [ABSTRACT FROM AUTHOR]

Sedimentological characteristics of the clastic sediments deposited in the Northwestern Arabian Sea at the ODP core sites 723A and 722B are used to reconstruct the paleoclimatic changes recorded during the last 150 kyrs. ODP site 723A is situated at 808 m water depth on the continental margin of Oman, whereas ODP site 722B is located at 2028 m water depth on the Owen Ridge. Clay minerals such as palygorskite, illite, chlorite, smectite, kaolinite, and non-clay minerals, quartz and feldspar, are present in both cores. However, palygorskite and illite dominated the clay mineral assemblage at core 723A, and illite dominated over palygorskite in the clay mineral assemblage at core 722B. Illites are dominantly well crystalline, with slightly poorer crystallinity occurring during Holocene and interglacial stages. Chemically illites are Mg-rich with slightly Al-rich illites associated with aforesaid stages. The higher values of all moisture-clay based humidity tools (ratios of kaolinite/illite, kaolinite/chlorite, smectite /(illite+chlorite), kaolinite/palygorskite) are dominantly associated with stronger monsoon based weathering during the interglacial stages, Holocene and interstadial events. The increased total carbonate, elemental concentrations (calcium, barium and phosphorous) and decreased magnetic susceptibility values correlate with the enhanced monsoon intensities during the above events. Glacial stages and millennial-scale drier events (Heinrich, Younger Dryas and stadial events) are marked by the massive influx of wind borne terrigenous material, dominated by clay minerals with higher silicon and aluminium contents; they have increased sediment accumulation rates at both sites. The clay proxies and other sedimentological data demonstrate monsoonal oscillations at 40, 23, 6.3, 4.4 and 3.5kyr cycles in Milankovitch and sub-Milankovitch time scales. The present study suggests that the detritus are mainly eolian and primarily originated from the nearby continental areas of Oman, the Arabian Peninsula, Persian Gulf and Iran-Makran regions. The northwesterly wind played a significant role in sediment transportation into the present sites throughout the studied period. The southwest summer and northeast winter monsoon winds played minor roles in the above activity during the interglacial and glacial stages, respectively. The Indus River discharges (predominantly of glacial origin), although low, have contributed some clay minerals in the deeper water core site. [ABSTRACT FROM AUTHOR]

Soil resources and their quality in the desert region of Oued Righ, located in northeastern Algerian Sahara, have emerged as unifying concepts to approach the larger issue of sustainability of oasian ecosystems in general, and agriculture in particular. This study aims to characterize and classify using physicochemical, mineralogical and micromorphological analyses, thirteen pedons located in different landscapes positions, including butte, plateau, piedmont, alluvial plain, playa, and claypan, to provide information about the genesis, classification, and properties of the Oued Righ soils. The results showed that the parent materials (calcareous and gypsiferous), as well as the topographic conditions, greatly influence soil development and its distribution in the study area. The soils of the Oued Righ region are generally slightly alkaline and saline, have coarse texture, especially at the soil surface, and are very rich in gypsum accumulations. These soils are classified as Aridisols and Entisols. The clay mineralogy results revealed that detrital input and inheritance are possibly the main sources of palygorskite, kaolinite, smectite-chlorite, and illite. Thin-section observations revealed that calcite coatings on grains and voids, calcite nodules and gypsum macro- and microcrystals were common pedofeatures observed in the studied soils. Hence, the actual hydrological regime in the study area is not compatible with the data obtained; therefore, the majority of pedons should be considered as paleosols. [ABSTRACT FROM AUTHOR]