X-ray Fluorescence Analysis Research Articles

Toxicity in 3D: XRF Analysis for the Presence of Heavy Metals in a Historical Stereograph Collection at Queen’s University Library, Canada

ABSTRACT This study employs non-destructive X-ray fluorescence (XRF) spectroscopy to identify the presence of potentially harmful heavy metals in a collection of nineteenth century stereographs housed at W.D. Jordan Rare Books and Special Collections at Queen’s University in Kingston, Ontario, Canada. Stereographs were extremely popular forms of entertainment and education in the Victorian era. As a result, they are common in archives, libraries, galleries, museums, and personal collections alike. This article provides an introduction to the history of stereographs, a background on their production, and pXRF analysis into the composition of pigments present on the stereograph mounts. Sixty-nine stereographs were selected for pXRF analysis, dating between 1852 and 1940, with the majority of the stereographs dating prior to 1895. Many of these cards are brightly coloured in greens, oranges, yellows, and pinks. Research revealed that arsenic-based pigment was common among all green stereograph cards analysed, lead-based pigment was common among all orange stereograph cards analysed, and lead- and chromium-based pigments were common among all the yellow cards analysed. However, additional analytical techniques need to be employed for definitive pigment identifications. This study demonstrates that hazardous pigments from the nineteenth century extend beyond wallpapers, books, and textiles and are likely to be pervasive in many heritage workplaces. This research highlights the importance of educating staff who work with archival collections. Understanding the scope of toxic pigments in archival collections is critical to ensuring proper handling, storage, and mitigation strategies to protect both the health of individuals and the integrity of these historically significant artifacts.

Thermal plasma technology applied to the inertization process of the inorganic fraction of sewage sludge generated from municipal wastewater treatment plant

Abstract This study investigates the thermal plasma pyrolysis process for inertizing the inorganic fraction of sewage sludge from municipal wastewater treatment plants. The aim is to assess its effectiveness in waste inertization. Lab-scale experiments were conducted to process the sludge thermally. Elemental composition analysis was done using x-ray fluorescence (XRF), thermogravimetry coupled with mass spectrometry (TGA-MS) and x-ray diffraction (XRD). The XRF analysis showed an initial composition of Si, Al, Fe, and Ca, corresponding to 86.8% of the inorganic matter of the sludge. TGA-MS analysis showed a significant mass loss between 200 and 650°C, corresponding to organic matter volatilization, methane conversion, and dehydrogenation of polymorphic silicon. XRD analysis revealed a dried sludge crystalline structure composed mainly by SiO2, CaCO3, and AlPO4, and after plasma treatment, the remaining composition of the slag was primarily SiO2 amorphous. Mass and energy balances, considering thermodynamic equilibrium and chemical reactions, are performed. The mass balance calculations identified the most probable composition of the sludge, and energy balance calculations determined a net energy requirement of 399 kWh for plasma inertization, with an additional 300 kWh to account for furnace losses. Solubility and leaching tests confirm the inert nature of the residue. Power requirements are estimated at 700 kW for processing 350 kg h−1 of decarbonized sludge. These findings are crucial for optimizing plasma inertization processes in wastewater treatment plants. This work presents a novel approach by combining a computational prediction for an industrial-scale plant with a direct experimental assessment of the plasma treatment process.

Monitoring and Prevention Strategies for Iron and Aluminum Pollutants in Acid Mine Drainage (AMD): Evidence from Xiaomixi Stream in Qinling Mountains

Acid mine drainage (AMD) generated during the exploitation and utilization of mineral resources poses a severe environmental problem globally within the mining industry. The Xiaomixi Stream in Ziyang County, Shaanxi Province, is a primary tributary of the Han River, which is surrounded by historically concentrated mining areas for stone coal and vanadium ores. Rainwater erosion of abandoned mine tunnels and waste rock piles has led to the leaching of acidic substances and heavy metals, which then enter the Haoping River and its tributaries through surface runoff. This results in acidic water, posing a significant threat to the water quality of the South-to-North Water Diversion Middle Route within the Han River basin. According to this study’s investigation, Xiaomixi’s acidic water exhibits yellow and white precipitates upstream and downstream of the river, respectively. These precipitates stem from the oxidation of iron-bearing minerals and aluminum-bearing minerals. The precipitation process is controlled by factors such as the pH and temperature, exhibiting seasonal variations. Taking the Xiaomixi Stream in Ziyang County, Shaanxi Province, as the study area, this paper conducts field investigations, systematic sampling of water bodies and river sediments, testing for iron and aluminum pollutants in water, and micro-area observations using field emission scanning electron microscopy (FESEM) on sediments, along with analyzing the iron and aluminum content. The deposition is analyzed using handheld X-ray fluorescence (XRF) analyzers, X-ray diffraction (XRD), and visible–near-infrared spectroscopy data, and a geochemical model is established using PHREEQC software. This paper summarizes the migration and transformation mechanisms of iron and aluminum pollutants in acidic water and proposes appropriate prevention and control measures.

A simultaneous X-ray fluorescence and diffraction analysis method for internal depth profile probing of the volume of material

A simultaneous X-ray fluorescence (XRF) and X-ray diffraction (XRD) analysis method for probing the internal depth profile of a material using tungsten target and cadmium telluride (CdTe) detectors is presented. To select a suitable target source, a Geant4 simulation is used to simulate the characteristic X-ray photon numbers produced by metallic materials with atomic numbers ranging from 24 to 92. The fluorescence analysis demonstrates the ability to measure intensity-depth profiles to greater than 500 μm depth in CeO2 powder, at least 400 μm depth in Er2 O3 powder, at least 200 μm depth in WO3 powder and up to 500 μm depth in Bi2 O3 powder. In addition, the diffraction analysis demonstrates the capacity to measure intensity-depth profiles to a depth of greater than 5 mm in silicon powder, at least 2 mm depth in nickel powder and up to 200 μm depth in tungsten powder. This method could be extended to component and phase detection in the safety inspection of flammable and explosive materials.

Preliminary studies for the standardization of a pXRF analyzer via ICP-OES for the accurate quantification of Pb in new paint.

Determining lead (Pb) concentrations in new paints using spectroscopic methods such as Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) requires technical expertise, consumables, equipment for method preparation, and instrumentation that can be cost prohibitive and difficult to maintain in low and middle-income countries (LMICs). Although portable X-ray Fluorescence (pXRF) analyzers are less expensive and simple to operate, their inaccuracy has limited their use to screening for the analysis of Pb in new, dried paint. To determine the limits of pXRF analyzers, new paint samples were purchased, dried, homogenized, and analyzed via pXRF and ICP-OES. Pb concentrations determined via pXRF were ∼27% lower than those determined by ICP-OES. Interestingly, the concentrations determined by both methods exhibited a strong linear correlation. The resulting equations were used to calibrate an individual pXRF analyzer, improving the accuracy of the pXRF result to within ±4.4% of verified concentrations of two certified reference materials. Additionally, eleven new paint samples from Benin and Türkiye were analyzed via pXRF, and their calculated concentrations were similar within ±10% of concentrations as verified by ICP-OES. This method requires no acid digestion or dilutions and provides an alternative method for the determination of Pb in new paint in LMICs.

The early development of a combined micro- and full-field X-ray fluorescence analysis system using white X-rays at PLS-II.

X-ray fluorescence (XRF) is widely used to analyze elemental distributions in samples. Micro-XRF (µ-XRF), the most basic conventional XRF technique, offers good spatial resolution through precise 2D scanning with a micrometre-sized X-ray source. Recently, synchrotron based XRF analysis platforms have achieved nano-XRF with highly focused X-rays using polycapillary optics or mirrors, leveraging the excellent coherence of synchrotron radiation. However, XRF techniques are hindered by long data acquisition times (exceeding several hours) due to their point-by-point scanning approach, impeding large-area elemental mapping. Full-field XRF (FF-XRF), developed in the 2010s and based on the high brilliance of synchrotron X-rays, enables significantly shorter (less than a few minutes) data acquisition times via single-exposure imaging using a 2D X-ray detector. Nevertheless, it is constrained by relatively low spatial resolution and sensitivity. Hence, a new XRF platform is required to accommodate resolution demands to cover diverse experimental purposes. In this study, we developed a preliminary model of a novel XRF system that combines micro- and full-field XRF setups to address these limitations. This system allows easy mode switching while maintaining the region of interest of the imaging system within a single apparatus, simply by rotating the sample to face either detector depending on research purposes. We anticipate that this new XRF system will be widely utilized in various research fields as the initial XRF setup at Pohang Light Source-II.

Spectral Data Fusion From Handheld Laser-Induced Breakdown Spectroscopy (LIBS) and X-ray Fluorescence (XRF) Analyzers for Improved Detection of Cerium in a Simulated Dispersal Accident.

This work implements a mid-level data fusion methodology on spectral data from handheld X-ray fluorescence and laser-induced breakdown spectroscopy analyzers to quantify plutonium surrogate (CeO) contamination in soil samples for the first time. Spectral data from each analyzer were used independently to train supervised machine learning regressions to predict Ce concentration. Fused features from both data sets were then used to train the same models, comparing prediction performance by evaluating model precision and sensitivity. Fusing principal component scores from the two sensors yielded an order of magnitude improvement in precision and sensitivity of predictions made with an artificial neural network, compared to predictions made by models trained on independent sensor data. Lastly, a boosted ensemble trained on the fused spectral features yielded an ideal predictor with root-mean-squared error on the order of 10-6 and calculated limit of detection order 10-5 wt.

Effect of high temperature isothermal annealing on optical properties of Gd<sub>3</sub>Al<sub>x</sub>Ga<sub>5-x</sub>O<sub>12</sub> (x = 1—3) and Gd<sub>3</sub>Al<sub>2</sub>Ga<sub>3</sub>O<sub>12</sub>:Ce<sup>3+</sup> crystals

Crystals of gadolinium-aluminum-gallium garnets with the following charge compositions: Gd3AlxGa5-xO12 (x = 1—3) and Gd3Al2Ga3O12:Ce3+ were grown The influence of high-temperature annealing in air on the optical properties of these crystals has been established. It was shown that annealing does not affect the oxidation state of cerium. Using X-ray fluorescence analysis, a gallium deficiency was established in all the studied crystals.

Characterization and catalytic activity of Co/Mo-modified activated carbons derived from orange peels in limonene oxidation.

The possibility of using orange peels for the preparation of porous activated carbons by the chemical activation with H3PO4 and the application of the obtained carbonaceous materials as the metal catalyst supports was investigated. Activated carbon and carbon-metal materials were used as the limonene oxidation catalysts. The materials were characterized by the following instrumental methods: the sorption of N2 at-196°C, XRD (X-ray diffraction), FTIR (Fourier transform infrared spectroscopy) and SEM (Scanning Electron Microscope), XPS (The X-ray photoelectron spectroscopy). XRF (X-ray Fluorescence) analyses were applied to determine the elemental (Co, Mo) content in the studied samples activated carbons. The activity of the obtained catalysts was tested in the oxidation of limonene to limonene oxide (the main product), carveol, carvone and perillyl alcohol. Oxygen was used as the oxidant in the oxidation processes. The results presented in this work showed that by the modification of the activated carbon with metal compounds, i.e. cobalt and molybdenum, it is possible to obtain more active catalysts for limonene oxidation compared to activated carbon not enriched with these metal compounds. The molybdenum catalyst (AC_OP_Mo) proved to be the most active catalyst. It allowed to obtain the high selectivity of limonene oxide (37mol%) at the high conversion of limonene (58mol%).

XRF and μ-tomography investigations of gold jewellery from the Middle Bronze Age from the Nerkin Naver burial mound (Armenia)

Abstract. The article summarizes complex studies on X-Ray Fluorescence (XRF), μ-tomography, and elemental analysis of a unique golden artefact from burial mound No. 10 of Nerkin Naver (Armenia), which according to the results of radiocarbon analysis is a contemporary of the epoch when the masterpieces of jewellery art of the III dynasty of Ur of the Sumero-Akkadian kingdom of Southern Mesopotamia (2111–2003 BC) were created. A jewelry obtained in tis burial mound and dated back to 2133–1954 BC were investigated to clarify the design, composition and manufacturing technique. We performed comprehensively analysis of the artifact using modern methods of the natural sciences. The results showed that this jewelry is made of gold with more than 80% of purity and infilled by the gypsum. Tomographic studies allowed suggested particular way of production and visualize the structure of golden shell and infill material separately. Basing on the suggestions about artefact composition and structures, its mass was calculated. Calculated and physically measured mass are in good accordance.

Development of a composite material based on Al2O3 for use in waste combustion plants

Catalytic fluidized bed combustion is the most environmentally friendly and energy efficient way of processing various fuels, including low-grade ones. The technology involves the oxidation of volatile substances on the surface of catalyst particles diluted with an inert material in a fluidized bed. The traditional use of quartz sand as an inert material leads to accelerated destruction of the catalyst during operation by attrition. The work is devoted to the study of the effect of magnesium modification of spherical γ-Al2O3, used as a carrier for a deep oxidation catalyst (DOC) in a fluidized bed, and the development of an inert material capable of minimizing DOC losses. The modified carrier was obtained by impregnating spherical γ-Al2O3 granules with a Mg-containing precursor solution (nitrate and acetate) followed by calcination of granules at 800 °C. The obtained granules were studied by X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectroscopy (ICP-OES), low-temperature nitrogen adsorption (BET), scanning electron microscopy (SEM). Their mechanical strength and catalytic activity in CO oxidation were also determined. A linear increase in the strength characteristics of γ-Al2O3 was found with the introduction of magnesium from 2 to 9 wt. %. In laboratory conditions, the use of the selected material made it possible to reduce the loss of the catalyst at 4.5 -hour attrition test by 3 times compared with quartz sand.

Design and Application of a Hemispherical XRF Secondary Target

ABSTRACTIn x‐ray fluorescence analysis (XRFA), the use of secondary targets to suppress measurement background is a common practice aimed at reducing detection limits. However, conventional polarized secondary targets often exhibit low conversion efficiency of primary x‐rays. In this paper, we propose a novel hemispherical secondary target designed to exploit a focusing‐like phenomenon for primary x‐rays, thereby enhancing the conversion efficiency and achieving improved background suppression. The optimal dimensions of the hemispherical secondary target are determined through theoretical calculations, and further validated through Monte Carlo simulations and experimental analysis. Our findings reveal a substantial enhancement in the peak‐to‐background ratio when compared to traditional polarized secondary targets. Specifically, for a 1000‐ppm Ce sample, the peak‐to‐background ratio increased from 8.45 to 9.78 with the implementation of the hemispherical secondary target. Similar improvements were observed when measuring a 1000‐ppm Ce sample, relative to direct excitation. Furthermore, the relative error between the system and the ICP‐MS measurement results of the rare earth sample remains within 5%, underscoring the effectiveness of the hemispherical secondary target in XRFA applications.

A provenance study on the ceramics excavated at the Varzaneh Plain, central Iran

Forty-six ceramic shards from the Early Bronze Age (EBA) archaeological site of Tappeh Gabri (the archaeological site 013), dated back to the latter half of the third millennium BCE and located at the Varzaneh Plain, central Iran, were studied using micro energy dispersive X-ray fluorescence (µ-EDXRF) and petrographic analysis. The precision and accuracy of quantitative data obtained by µ-EDXRF were tested using a series of geological certified reference materials (CRM). The expanded uncertainty and the Mantel test on data obtained by µ-EDXRF showed accurate and precise quantitative µ-EDXRF estimation of elements present in the CRMs above their quantification limit. We show that the majority of the ceramics at the Varzaneh Plain is most probably local product. Discussions prompted collecting further compositional data and performing petrographic investigation from the ceramic shards from southern and south-western Iran in order to shed light on the origin of the ceramic shards excavated at the Varzaneh Plain.

Impact of Physical Processes and Temperatures on the Composition, Microstructure, and Pozzolanic Properties of Oil Palm Kernel Ash

In recent decades, the global use of ashes derived from agro-industrial by-products, such as oil palm kernel shells, which are widely cultivated in Colombia and other tropical regions of the world, has increased. However, the application of these ashes in engineering remains limited due to their heterogeneity and variability. This study utilized scanning electron microscopy (SEM) to assess the influence of calcination temperatures, ranging from 500 °C to 1000 °C, as well as the physical processes of cutting, grinding, and crushing, on the silica content of the studied ashes. Specifically, the sample labeled M18A-c-m-T600°C-t1.5h-tr1h, which was subjected to a calcination temperature of 600 °C and underwent cutting and grinding before calcination, followed by post-calcination crushing, exhibited the highest silica concentration. Complementary techniques such as X-ray fluorescence (XRF) and X-ray diffraction (XRD), were applied to this sample to evaluate its feasibility as an additive or partial replacement for cement in concrete. XRF analysis revealed a composition of 71.24% SiO2, 9.39% Al2O3, and 2.65% Fe2O3, thus, meeting the minimum oxide content established by ASTM C 618 for the classification as a pozzolanic material. Furthermore, XRD analysis confirmed that the sample M18A-c-m-T600°C-t1.5h-tr1h is in an amorphous state, which is the only state in which silica can chemically react with calcium hydroxide resulting from the hydration reactions of cement, forming stable cementitious products with strong mechanical properties.

Physiological parameters and metal-accumulating capacity of the biofuel plant Miscanthus × giganteus cultivated on oil-contaminated podzol soil treated with humic preparations

Background. Physiological characteristics of the biofuel plant Miscanthus × giganteus J. M. Greef, Deuter ex Hodk. & Renvoize are currently attracting much attention due to its phytoremediation potential. The aim of this work was to study the content of photosynthetic pigments in the leaves of M. giganteus, the accumulation of metals in the rhizosphere and aboveground organs, as well as the morphological parameters of plants cultivated on oil-contaminated soil and exposed to treatment with humic preparations. Materials and Methods. During field experiments, five experimental plots (PC and P1–P4) with an area of 1 m2 were laid out on podzol soil in the territory adjacent to the Starosambirske oil field. The PC plot was not subjected to any experimental treatment. The soil in plot P1 was planted with M. giganteus rhizomes; the soils in plots P2–P4 were contaminated with 10 L/m2 of crude oil and then planted with M. giganteus rhizomes. Before planting the rhizomes on plots P3 and P4, these were soaked in solutions of Fulvital® Plus Liquid and Humifield® Forte, respectively. During the growth period, the plants were sprayed twice with humic preparations. Shoot height and leaf width, a- and b-type chlorophyll (Chla and Chlb, respectively), total chlorophyll (Chla+b) and carotenoid concentrations were measured using standard methods. The content of metals (Ca, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn) in soil and plant samples was assessed by X-ray fluorescence analysis using an Elvax Light SDD Analyzer. Results. The cultivation of M. giganteus on oil-contaminated soil did not affect shoot height or leaf width of plants, but it reduced the content of Chla, Chlb, Chla+b and carote­noids in plant leaves. Treatment of plants with humic preparations led to an increase in pigment concentrations in the leaves at different growth periods. Oil-contaminated soil planted with M. giganteus showed elevated levels of Cr and Ni. The cultivation of M. giganteus treated with Fulvital® Plus Liquid resulted in increased Ca, Mn and Ni contents in rhizosphere soil of an oil-contaminated plot. Growing M. giganteus on oil-contaminated soil resulted in significant decreases in Ca, Cr, Fe, K, Mg, Ni and Zn concentrations in plant stems. Treatment with humic preparations increased the content of the mentioned metals in the stems and the concentration of Mg and Ni in the leaves of plants from oil-contaminated soil compared to those in untreated plants. According to the bioaccumulation factor (BF) values, M. giganteus leaves have a high accumulation potential for Ni and Ca (BF>1), a medium accumulation potential for Mg, K and Cr (BF from 0.1 to 0.32) and a low accumulation potential for Fe and Zn (BF<0.1). The BF values of metals in leaves and stems decreased when plants were grown on oil-contaminated soil. Conclusions. Humic preparation treatment has a positive effect on the physiological parameters of M. giganteus grown on oil-contaminated podzol soil. The ability of M. giganteus to extract Ni from soil may mediate the plant’s phytoremediation potential. In this regard, the cultivation of M. giganteus in combination with its treatment with humic preparations will be promising on lands contaminated with oil and petroleum products.

COMPREHENSIVE PROCESSING OF MINERAL RAW MATERIALS FROM COAL MINE WASTE DUMPS: PROPERTIES, VALUABLE PRODUCTS, AND RESOURCE ACCOUNTING SYSTEM

Objective. Experimental studies on the chemical and mineralogical composition of coal mine spoil heaps and the potential for processing them to obtain valuable mineral-raw materials. Development of an analytical tool for accounting and forecasting the resource potential of coal mine spoil heaps. Methods. To achieve the objective, X-ray fluorescence analysis, X-ray phase analysis, granulometric analysis, laboratory studies of mineral raw material enrichment using sieve fractionation and gravity separation, as well as analytical studies of spoil heap resource accounting were employed. Results. The chemical, mineralogical, and granulometric composition of spoil heaps from a coal mine in the Western Donbas region was investigated, enabling the identification of a processing strategy to obtain a range of products: coal concentrate, crushed stone mixture, sand fraction, and clay fraction. It was established that gravity separation of coarse fractions in a heavy medium created with clay slurry demonstrated high separation efficiency, yielding a significant low-ash coal fraction and a high-ash rock fraction. In contrast, spiral separator processing demonstrated significantly lower low-ash coal recovery. A technological processing scheme for spoil heaps to obtain a complex of valuable products was developed, and forecast indicators were evaluated. A methodological system for accounting the resource potential of a coal mine waste dump has been proposed in the form of an informational database. This system allows for tracking changes in the dumps structure, identifying zones of attractive resource accumulation for economic efficiency of processing operations in the long term. Scientific novelty. The use of clay suspension from washed spoil heaps to create a heavy medium for the beneficiation of coarse fractions allows for the recovery of up to 95% coal concentrate with 11% ash content, contributing to resource conservation. Practical significance. A technological scheme for obtaining a range of valuable products for the energy and construction industries has been developed. An analytical tool for resource potential accounting and calendar planning for spoil heap formation has been created, enabling operational identification of resource concentration zones within spoil heaps and their sections. Keywords: coal mine, spoil heap, valuable resource, chemical composition, mineralogical composition, granulometric composition, gravity separation, resource accounting.

Leaching of rare earth elements from Malaysian monazite: effect of dephosphorization

Abstract Phosphates interfere the leaching process and raise environmental concerns when it comes to the extraction of rare earth elements (REEs) from monazite. This study investigates the dephosphorization behaviour of Malaysian monazite through a statistical design of experiments approach, focusing on the variables of baking reagents, roasting time, and temperature. The raw monazite sample was characterized using X-ray fluorescence (XRF) and X-ray diffraction (XRD) analyses, revealing the presence of phosphorus (P), rare earth elements (REEs) including cerium (Ce) and lanthanum (La), thorium (Th), and trace elements such as sodium (Na), iron (Fe), silicon (Si), and magnesium (Mg). The XRD analysis confirmed the dominance of CePO4 and LaPO4 phases in the monazite sample. The dephosphorization process was optimized, with the highest rare earth elements recovery achieved at 250°C for 4 hours using potassium hydroxide (KOH) as the baking reagent. In addition, the sample with the lowest concentration of phosphorus leached 84.1% of the rare earth elements. It indicates that a high level of phosphorus removal can lead to a significant recovery of rare earth elements (REEs) and provides significant information for environmentally friendly REE extraction practices.

Analyses of Heavy Metals Bioaccumulation in the Organs of Clarias gariepinus Following Exposure to Sub-Lethal Concentrations of Waste Burnt Tire Residues

This study evaluated the bioaccumulation of certain heavy metals of waste burnt tire residues (WBTRs) in certain organs (viz-gills, liver, kidney and muscles) of Clarias gariepinus following exposure to sublethal concentrations (SLCs) of water-soluble fractions (WSFs) of WBTRs. Clarias gariepinus (average weight of 47.95±0.34g and length of 15.54±0.36cm) were exposed to SLCs at different concentrations (0.00, 0.23, 0.47, 0.94, 1.87, and3.74 ppm) of WSFs of WBTRs for a period of fifty-eight days. Heavy metal concentrations in WBTRs and in the organs of the experimental fish were measured using a handheld X-Ray Fluorescence Analyzer (NitonXL3T). Results showed that strontium, lead, zinc, cobalt, bismuth, rubidium, gold, tungsten, iron, thorium, arsenic, copper, and niobium were detected in WBTRs although the maximum level of zinc was perceived however, no significant difference (P>0.05) was observed as compared to the control group regarding heavy metal accumulation in muscles, 53.10±12.78; liver, 56.30±76.96; kidney, 164.54±12.78; and gills, 241.36±146.87 of the exposed fish. The high levels of heavy metals present in WBTRs are of great concern as potential detrimentl pollutants to the aquatic ecosystem. These allochthonous inputs get into the aquatic ecosystem through sewage flow and runoffs effluents. Resident non-target communities particularly fishes from such polluted aquatic systems with WBTRs become vunerable and incriminated with attendant high levels of heavy metals that could be detrimental to human consumers.

Experimental and computational insights into the design of pH-responsive sodium alginate-coated nanoparticles for targeted mesalazine delivery

Halloysite-alginate beads loaded with mesalazine or 5-amino salicylic acid (5-ASA), a model anti-inflammatory drug, were investigated for their ability to protect the drug from acidic degradation during gastrointestinal transit. X-ray fluorescence (XRF) analysis confirmed the composition of the halloysite nanotubes, while zeta potential analysis corroborated their colloidal stability. Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD) investigations confirmed the effective production of the nanocomposite and provided insights into the interactions between its components and crystalline structure. The structure and homogeneous size distribution of the halloysite nanotubes (HNT) were examined using transmission electron microscopy (TEM). Additionally, scanning electron microscopy (SEM) images indicated a spherical shape and a relatively rough bead surface. Upon initial incubation in a simulated gastric medium (pH 1.2), the beads remained unchanged. In contrast, incubation in a simulated intestinal medium (pH 6.8) led to bead swelling, floating, and erosion. Furthermore, the formulation exhibited a smart, pH-sensitive release mechanism, achieving complete drug release over 750 minutes, highlighting its potential for sustained and targeted drug delivery. Release data for 5-ASA were well-fitted to the Korsmeyer-Peppas and Higuchi models, indicating distinct mechanisms governing the release from the composite material. Density functional theory (DFT) analyses revealed specific interactions between 5-ASA and halloysite, characterized by strong hydrogen bonding and Lewis acid-base interactions with aluminol sites, alongside reduced van der Waals forces in the hydrophobic siloxane regions.

Effect of fine aggregate replacement with limestone Slurry Waste in Self Compacting Concrete: A Microstructural Approach

The stone processing generated Dimensional Limestone Slurry Waste (DLSW) was used in Self-Compacting Concrete (SCC) to evaluate the compressive strength and analyze microstructure. X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) analysis of DLSW was carried out, and its results revealed the presence of CaO (38.93 %) and SiO2 (24.33 %), which was associated with calcite and quartz. The rough, angular shape of particles, fineness, and presence of calcite of DLSW help to get optimum density and enhanced compressive strength at 28 days in modified SCC up to a 45 % replacement level. The Mercury Intrusion Porosimetry (MIP), Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometer (EDS) and Ultrasonic Pulse Velocity (UPV) analysis results support the improvement of compressive strength claims.