Hydrothermally-calcined waste paper ash nanomaterial as an alternative to cement for clay soil modification for building purposes

It has been observed that clay soil cannot be used for building design, unless it is modified by firing or with cement. Either method of stabilization can adversely affect the environment and public health just like indiscriminate dumping or open burning adopted in developing countries as the prevalent disposal technique for waste papers. This paper sought to examine the feasibility of using assorted waste papers to derive an alternative stabilizer to Portland Limestone Cement for modification of clay soil into composite materials suitable for building design. Specifically, clay-based composites were fabricated at 0 %, 5 %, 10 %, 15 %, and 20% replacement levels by weight with cement, and then hydrothermally-calcined waste paper ash nanomaterial (HCWPAN). Water absorption, sorptivity, bulk density, thermal conductivity, specific heat capacity, thermal diffusivity, flaking concentration, flexural strength, and compressive strength were investigated for each of the fabricated samples. Irrespective of the stabilizing agent utilized, 10% loading level was found to be the optimum for possession of maximum mechanical strength by the samples. Only samples with the HCWPAN content were found to be capable of reducing building dead loads and improving thermal insulation efficiency over un-stabilized clay material, if applied as walling elements in buildings. Generally, it was revealed that the cement and HCWPAN have comparable influences on the properties of clay soil, thus indicating that HCWPAN could be utilized as an alternative stabilizer to cement. In addition, the preparation of HCWPAN was found to be more energy-saving than that of the cement.

CHARACTERIZATION OF CLAY MATERIALS USED FOR POTTERY PURPOSES FROM RENDENG, MALO, BOJONEGORO

Clay material from Rendeng, Malo, Bojonegoro was studied by mineralogy and physicochemical characterization to evaluate its potential suitability as a raw material in pottery application. X-ray Diffraction (XRD) and Fourier Transform-Infrared (FTIR) spectrometry were used to establish the mineralogy composition. Meanwhile the physical properties were identified by particle size distribution and consistency limits. Chemical composition was carried out by X-ray Fluorescence Spectrometer (XRF). The results of XRD characterization revealed that clay from Rendeng Village, Malo, Bojonegoro contained kaolin, quartz, and feldspar. Physical characterization shows that clay material is a less plastic type based on Atterberg method. Based on the chemical compositions indicated that SiO2, Al2O3, CaO, and Fe2O3 were abundance oxides. Therefore, clay from Desa Rendeng was only suitable for the pottery purposes because most of its mineral compositions did not meet the quality requirements for making advanced ceramics.

An Investigative Study on the Progress of Nanoclay-Reinforced Polymers: Preparation, Properties, and Applications: A Review

Nanoclay-reinforced polymers have attracted considerable universal attention in academic and industrial research due to their outstanding properties and their ever-expanding utilization in diversified applications. In that regard, in the present review, the structure of layered silicate clay, as well as procedures for clay material modification, are outlined. We also discuss the general characterization techniques, synthesis methods, and various properties of polymer–clay nanocomposites (PCNs), and some examples likewise are depicted from the scientific literature. The study’s primary goal is to provide an up-to-date survey of polymer–clay nanocomposites and their specific applications in industries such as automotive, flame-retardant, and biomedical applications, coating, and packaging.

Recently Discovered Thick Bentonite Bed Hosted by the Lithothamnium Limestones (Badenian) in the Polish Part of the Carpathian Foredeep: The Evidence for Volcanic Origin

In this paper, we discuss the hypothesis on the volcanic origin of the precursor sediments for a thick (0.6 m) clay bed, hosted by the sequence of lithothamnium limestones of the Pińczów Formation. Combined X-ray powder diffraction, imaging methods (optical and electron microscopy), and chemical analysis were used to document the volcanic markers, which were preserved in the rock studied. The results obtained show that the clay bed discussed is bentonite in origin. This bentonite, which can be called Drugnia Rządowa bentonite, is composed almost entirely of montmorillonite with little admixtures of quartz and biotite. A small amount of calcite is present, but only in the top of the bed. Despite that, the bentonite contains nothing but clay material—it is a model example of entirely altered pyroclastic rock, which retains texture originally developed in volcanic glass fragments and reveals the preserved original features of the precursor fallout pyroclastic deposits (rhyolitic in character). The thick bentonite beds, discovered for the first time within the Badenian lithothamnium limestones of the Pińczów Formation, can be considered as a record of a violent, explosive volcanic event related to the closure of the Outer Carpathian basin and the development of the Carpathian Foredeep.

Removal of Cd (II) Ions from Bioretention System by Clay and Soil Wettability

In this work, a silane modifier with benzyl substitutes (OFS-B) and linear substitutes (OFS-L) was used to modify bentonite clay and soil, and the results were characterized by Fourier transform-infrared absorption spectroscopy (FT-IR) and powder-X-ray diffraction (XRD) analysis. A contact angle analysis was performed to determine the wettability of modified clay and soil. The findings revealed that silane-modified OFS-L clay and soil produced wettable surfaces, while OFS-B exhibited hydrophobic properties. These clays and soils were used in a bioretention system for Cd (II) removal. In the study, seven different types of bioretention systems, including natural, OFS-L, and OFS-B modified clay and soil, as well as natural, OFS-L, and OFS-B modified soil, were applied to Cyperus alternifolius plants without an additional layer. The removal capacity of Cd (II) was measured in the following order: modified clay > modified soil > original clay/soil > no layer, i.e., 99.48%, 92.22%, 88.10/78.5%, and 30.0%, respectively. OFS-L removed more Cd (II) than OFS-B during the modification. OFS-L now improves the bioavailability and accumulation of Cd (II) in the plant (18.5 µg/g) and has a higher chlorophyll-b concentration (1.92 mg/g fresh weight) than other systems. The wettable clay exhibited clay leaching into the various levels of the bioretention system. In the bioretention system, benzyl substituted clay prevented the penetration of water and formed a Cd (II) agglomeration. When compared to non-wettable modifiers, these results indicated that wettable clay material could be a capable material for removing Cd (II).

The mud volcanoes at Santa Barbara and Aragona (Sicily, Italy): a contribution to risk assessment

The Santa Barbara and Aragona areas are affected by mud volcanism (MV) phenomena, consisting of continuous or intermittent emission of mud, water, and gases. This activity could be interrupted by paroxysmal events, with an eruptive column composed mainly of clay material, water, and gases. They are the most hazardous phenomena, and today it is impossible to define the potential parameters for modelling the phenomenon. In 2017, two digital surface models (DSMs) were performed by drone in both areas, thus allowing the mapping of the emission zones and the covered areas by the previous events. Detailed information about past paroxysms was obtained from historical sources, and, with the analysis of the 2017 DSMs, a preliminary hazard assessment was carried out for the first time at two sites. Two potentially hazardous paroxysm surfaces of 0.12 and 0.20 km2 for Santa Barbara and Aragona respectively were defined. In May 2020, at Aragona, a new paroxysm covered a surface of 8721 m2. After this, a new detailed DSM was collected with the aim to make a comparison with the 2017 one. Since 2017, a seismic station was installed in Santa Barbara. From preliminary results, both seismic events and ambient noise showed a frequency of 5–10 Hz.

Potential use of alluvial clays from Monoun in ceramics by adding feldspar from Batie (West-Cameroon) as a fluxing agent

The present study focuses on the use of feldspars from Batie granites (West-Cameroon) as a fluxing agent in ceramic applications, in order to reduce the energy cost of brick manufacture. Three alluvial clays were collected in the field using an auger and the feldspar sample was collected by hammering. Mineralogical, physical and geochemical analysis of alluvial clays samples were carried out, as well as the microscopy analysis of feldspar. The specimen of fired bricks was formulated with different proportions of feldspar (0%, 10%, 15%, 20%, and 25%) and calcined respectively at 750 °C, 850 °C, 950 °C and 1050 °C in an electric furnace. The physical analysis of the clay material showed a well graded granulometry composed of 3% gravel, 10% coarse sand, 23% fine sand, 13% silt and 51% clay. Thin section microscopic analysis revealed essentially perthites. The mineralogical analysis obtained by XRD on total powder shows that the alluvial clays are composed essentially of: 55.8% of total clays; 19.2% quartz; 14.2% goethite; 8.5% K feldspar; 1.2% anatase; 0.7% hematite and 0.4% gibbsite. Geochemical analysis shows that clay material consists of: SiO2, Al2O3, Fe2O3, TiO2, P2O5, MgO, CaO and K2O. The ceramic tests carried out on these bricks showed that their colors were red for all the formulations and temperatures tested. The sound of the bricks is metallic for the formulations of 20 and 25% of feldspar as from 850 °C. The flexural strength (greater than 3 MPa) and compressive strength (10–20 MPa) obtained at 20 and 25% of feldspar meet the standard of traditional ceramics requirements. The bricks obtained at 20 and 25% of feldspar and at a sintering temperature below 850 °C have good technological properties. It was observed that brick formulations with 0% of feldspar fired between 950 and 1000 °C are similar to those of 20 and 25% of feldspar fired at 850 °C).Highlights The alluvial clays from Monoun characterized have highest proportion of kaolinite and good mechanical properties (950 and 1050 °C). Thin section microscopic analysis of Batie feldspar revealed essentially perthites. The brick formulations with 0% of feldspar fired between 950 and 1050 °C are similar to those of 20 and 25% of feldspar fired at 850 °C.

Synthesis and Evaluation of Asymmetric Mesoporous PTFE/Clay Composite Membranes for Textile Wastewater Treatment

Asymmetric mesoporous composite PTFE membranes wit 40, 50, and 85 wt.% of a clay (kaolin) were fabricated and characterized using a scanning electron microscope equipped with EDX for morphology and elemental analysis. The surface chemistry of the membranes was checked using Fourier transform infrared spectroscopy. The effect of incorporating the clay on the hydrophilicity, permeability, morphology, and antifouling properties of the fabricated membranes was investigated. It was observed that incorporating kaolin particles improved the mechanical properties but decreased the contact angle of the membranes, thereby resulting in an improvement in the membrane permeability. The performance of the three composite UF membranes was evaluated through the treatment of a real textile effluent sample containing indigo dye. The results confirmed that these membranes are effective in the removal of COD, color, and turbidity. Indeed, at a transmembrane pressure of 2.5 bar, almost total removal of the turbidity, COD removal >85%, and color removal > 97% were attained. Furthermore, membrane A85 (with 85% clay) showed the best performance, with a water flux of 659.1 L.h–1.m–2.bar–1. This study highlights the potential of incorporating low-cost clay material for the enhancement of the performance of mixed organic/inorganic matrix membranes, which can be applied to textile wastewater treatment.

Ultrasonic Shaking of Glauconite Pellets with Diverse Reagents for a Comparison of Their K–Ar with Already Published Rb–Sr Results

A combined ultrasonic treatment, with de-ionized H2O, dilute HAc or dilute HCl, of three Mid-Miocene glauconite samples was applied to K–Ar date the different separates in order to compare the results with those obtained by the Rb–Sr method using the same three samples and that were analyzed strictly in the same way. Two aliquots yield opposite elemental and K–Ar trends, which suggests different initial mineral compositions for the various pellets. The K–Ar data of two untreated and leached L7 and L8 aliquots are almost within analytical uncertainty from 17.3 ± 0.6 Ma to 19.6 ± 0.7 Ma (2σ), while those of the third L10 sample are slightly higher at 22.1 ± 1.2 Ma (2σ). Comparatively, the earlier published Rb–Sr ages of the three untreated samples and of the leached aliquots gave similar data for the L7 aliquots by an isochron at 18.1 ± 3.1 (2σ) Ma and for the sample L8 by an isochron with an age of 19.6 ± 1.8 (2σ) Ma, while the untreated L10 aliquot yields a very high Rb–Sr date of 42.1 ± 1.6 (2σ) Ma. This untreated L10 glauconite fraction contains blödite, a Sr-rich carbonate that impacted the two isotopic systems differently. Generally, dilute HCl or HAc acids dissolve carbonates, sulfates, sulfites and oxides, while they do not affect the clay-type crystals such as glauconites. These soluble minerals can be identified indirectly, as here, by X-ray diffraction and the amounts of leached Na2O, CaO and Fe2O3 contents. Together with the leaching of some metallic trace elements, those of NaO confirm the leaching of metals and of blödite that are both hosted by the glauconite pellets. The occurrence of this Sr-enriched mineral explains the age differences of the non-treated aliquots and suggests a systematic leaching of any glauconite separate before isotope determination and, possibly, a comparison of the Rb–Sr and K–Ar results. Ultrasonic shaking appears appropriate for physical disaggregation of any contaminating grains that may remain hosted within the pellets, even after a preliminary H2O wash, which may dissolve and remove the soluble minerals but not the H2O-insoluble silicates. The K–Ar study completed here as a complement to a previous Rb–Sr study highlights, again, the importance of the preparation step in isotopic studies of glauconite-type and, by extension, of any clay material, as all occurring minerals can interfere in the final age determinations and, therefore, differently in the mineral assemblages. All those not in isotopic equilibrium need to be removed before analysis, including the soluble Sr or alkali-enriched ones.