Energy Dispersive X-ray Fluorescence Research Articles

Microwave Assisted Biodiesel Production from Waste Cooking Oil Using Steel Slags as Catalyst

AbstractAn innovative catalytic system for biodiesel synthesis starting from waste biomass (waste cooking oil, WCO) in the presence of waste material (steel slags) as the catalyst under microwave irradiation is described. The reaction conditions were optimized by using response surface methodology (RSM) based on Box‐Behnken Design (BBD) taking time, temperature, and catalyst weight as factors. The optimum conditions, leading to 97 % conversion of WCO into FAMEs (fatty acid methyl esters) were found to be: 18 min reaction time, 134 °C and 380 mg of catalyst for 1.0 mL of WCO. The recyclability of the catalyst was tested at different experimental conditions, and by increasing the reaction times for subsequent cycles, the catalytic efficiency remained steady. The alkalinity of both as‐received steel slags and steel slags recovered after three reaction cycles was tested with the Hammett indicator method. The steel slags were also characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X‐ray Fluorescence (ED‐XRF), X‐Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), X‐ray Photoelectron Spectroscopy (XPS).

Metal Contamination and Human Health Risk Assessment of Soils from Parks of Industrialized Town (Galati, Romania)

The aim of the present study was to evaluate the contamination state of the surface soil from 10 parks from Galati, Romania, and the health hazards of the soil. The soil samples, collected in each site from the playing ground and from the edge of the park, were analyzed by using combined Wavelength- (WDXRF) and Energy-Dispersive (EDXRF) X-ray fluorescence techniques. A total number of 27 chemical elements (Ag, Al, As, Ba, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Ti, V, Zn and Zr) were quantified in the urban soils, and the results were compared to the normal and alert values from Romanian legislation for toxic trace elements, as well as with European and world average values of element concentrations. The mineralogical analyses were performed by Scanning Electron Microscopy with Energy-Dispersive X-ray Analysis (SEM-EDX) and the Attenuated Total Reflectance–Fourier Transform Infrared technique (ATR-FTIR). To assess the soil contamination and the impact on human health of the presence of potential toxic elements and heavy metals in the soil, a series of pollution and health risk indices were used. All the results indicated an unpolluted to moderately polluted soil. The soil samples collected from the edge of the parks presented higher values for the specific pollutants, which originated from heavy traffic, such as Cu, Cr, Zn and Pb. The non-carcinogenic and carcinogenic risk to children was assessed using estimated daily intake (EDI) in relation to the pathways whereby pollutants can enter the human body, such as ingestion, dermal contact, inhalation and vaporization. Using the obtained values for EDI, the hazard quotient and hazard index were determined, which strengthen the formerly issued presumption that soil pollution is moderate and, by itself, does not present any threat to children’s health.

Some educational uses of EDXRF for technologists in health science

Abstract Physicists teach physics to students of various academic disciplines such as physics, chemistry, health sciences, biology, geology, environmental sciences, etc. Energy dispersive X-ray fluorescence spectroscopy (EDXRF) is a case of application of atomic physics in the real world. Students, through applications of EDXRF, may find out how the basic concepts of atomic physics can be used for elemental analysis of samples of their scientific interest and everyday life. This paper presents some educational implementations of EDXRF and highlights the importance of incorporating this spectroscopic method in undergraduate or postgraduate labs or lectures in the field of health sciences. Five experimental activities, a general one for understanding X-ray spectra and the others for the analysis of substances/materials related to chemistry/toxicology, dentistry, optics, and cosmetics, are presented and discussed.

Preliminary Assessment of Morphology and Elemental Composition of Fine Particulates in Selected Urban Areas of Java Island

Rapid urbanization and high population density in three major cities in Indonesia, Bandung, Jakarta, and Tangerang have led to significant air quality issues. Fine inhalable particles (PM2.5) with distinct morphologies and elemental compositions pose considerable health risks. This study evaluates the morphology and chemical composition of PM2.5 in these urban areas on Java Island. PM2.5 samples were collected for 24-hour periods using a Teflon filter with the Super Speciation-Air Sampling System (SuperSASS) following the EPA sampling schedule, from May to September 2022. The Teflon sample with the highest PM2.5 concentration, representative of both weekdays and weekends, was selected for morphological analysis using Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) and elemental characterization using Energy-Dispersive X-ray Fluorescence (ED-XRF) Epsilon. SEM images revealed distinct morphological characteristics at each site. In Bandung, particles were irregularly shaped, agglomerated, and flaky, with sizes ranging from 1.1-1.6 µm on weekdays and 0.9-1.3 µm on weekends. Jakarta has particles with semi-crystalline, tabular, elongated, and puff-like morphology, with sizes predominantly from 0.5-0.8 µm on weekdays and 0.9-1.3 µm weekends. In Tangerang, particles were irregularly faceted and agglomerated, with sizes between 0.5-1.3 µm on weekdays and 0.9-1.4 µm on weekends. Teflon-derived minerals (C,F) were present across all sites. EDX spectra revealed Ca-rich particles in Bandung, while S-rich particles were observed in Jakarta and Tangerang. XRF analysis further proved the major and minor elements, reflecting local pollution sources. The combined use of SEM-EDX and XRF offers a comprehensive profile of PM2.5, highlighting specific pollution sources in each city.

Performance of high-energy storage activated carbon derived from olive pomace biomass as an anode material for sustainable lithium-ion batteries

In this work, we investigate how activated carbon (AC) derived from olive pomace biomass can be used as an anode material in lithium-ion batteries. The biomass-derived activated carbon has the potential to be highly efficient, deliver high performance, sustainable, and cost-effective in LIBs-related production. The activated carbon is prepared by using H3PO4 as a chemical activation agent, and then calcining the obtained product at 500°C for different controlled atmospheres under (i) air (AC-Atm), (ii) vacuum (AC-Vac), and (iii) argon (AC-Arg). The different samples were systematically analyzed using scanning electron microscopy (SEM), High-resolution transmission electron microscopy (HRTEM), energy dispersive spectroscopy (EDS), X-ray fluorescence (XRF), X-ray diffraction (XRD), FT-IR and Raman spectroscopy, and thermogravimetric analysis (TGA) to assess their properties. The electrochemical properties of the carbonaceous materials were studied by galvanostatic cycling, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The results showed high specific capacity and stable cycling performance, with capacities of 288, 184, and 56 mAh g-1 at the current density of 25 mA g-1 after 70 cycles for AC-Arg, AC-Vac, and AC-Atm respectively. Furthermore, the CE efficiency was nearly 100% from the first cycles. This study opens up interesting prospects and offers promising opportunities for more efficient recovery of unused olive pomace waste, by integrating it into energy storage applications, particularly sustainable lithium-ion batteries.

Use of energy dispersive X-ray fluorescence to authenticate European wines with protected designation of origin. Challenges of a successful control system based on modelling

Consumers are willing to pay a higher price for food with geographical origin labels such as Protected Designation of Origin and Protected Geographical Indication. In this work, the elemental profile of wine obtained by XRF, combined with multivariate analyses, is used to authenticate 111 Croatian, Italian and Spanish red and white wines, 102 of them from 20 Protected Designations of Origin, reproducing the circumstances faced by control laboratories, using commercially available wines without traceability records. Wines that shared origin clustered together and separated from those of other regions following multivariate statistical tests. Classifications made using Soft Independent Modelling by Class Analogy were characterised by poor sensitivity and specificity. An alternative approach based on successive Partial Least Square Discriminant Analyses with consecutive classifications at country, region and finally, Protected Designation of Origin level, was developed and implemented with good accuracy results. In total, 88 % of the samples were correctly classified.

Energy Dispersive X-Ray Fluorescence Spectrometry Using a Matrix Corrected Fundamental Parameters Algorithm vs. Acid Digestion with ICP-AES: A Comparison of Two Methods for Soil Elemental Analysis

ABSTRACT Energy dispersive X-ray fluorescence spectrometry (ED-XRF) is evaluated as an alternative to conventional acid-mediated soil digestion methods for analysis of aluminum (Al), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), silicon (Si), strontium (Sr), titanium (Ti), and zirconium (Zr). The Kellogg Soil Survey Laboratory (KSSL) currently uses microwave-assisted digestion with inductively coupled plasma – atomic emission spectrometry (ICP-AES) to measure the 12 elements (Al, Ca, Fe, K, Mg, Mn, Na, P, Si, Sr, Ti, Zr). The equipment needed to conduct the digestion method is expensive, the materials are hazardous, and the method is laborious. The Kellogg Soil Survey Laboratory (KSSL) has observed variable elemental recoveries for certain elements. The objective of the study was to evaluate an ED-XRF method as an alternative to the KSSL digestion method. The literature offers few examples of X-ray fluorescence (XRF) method development and validation. The candidate ED-XRF method offered a more efficient, less expensive, and less hazardous approach for measuring the 12 elements. Relative to the digestion method, the candidate ED-XRF method showed improved precision and accuracy for specific elements.

Assessment of heavy metals concentration and health hazard indices in soil and plants from Kokona Local Government Area of Nasarawa State, Nigeria

Human dependence, on the plants grown on soil and the threat posed by contaminated soil to the ecosystem and general public has become a source of concern. The health risks caused by heavy metals concentration to the study area were evaluated. Fifteen (15) plant samples and soil samples each from the study area were collected and analyzed using an Energy Dispersive X-ray Fluorescence Spectroscopy (EDXRF) for Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), Copper (Cu), and Zinc (Zn). The Measured concentrations of these heavy metals were in the order of Cd>Ni>Cu>Zn>Pb>Cr for the plant samples and Cr>Cd>Ni>Cu>Pb for soil samples with Cd and Cr as the highest contributors to cancer risk in term of the carcinogenic risk estimate. The Health Hazard Index value for all pathways were found to be 7.34 x 10-1 making non-carcinogenic risk component less significant to the adult population and in case of children, the Hazard Index value was 1.21, a value greater than unity (1), which present a severe non-carcinogenic risk component to children living in the study area. The carcinogenic risk was found to be 8.68 x 10-6 implying that 1 person in every 5882 adults may be affected and 1 in 2725 children may be affected (9.6 x 10-5) These carcinogenic risk values were both higher than acceptable values.

Analysis of Acid Options in the Purification of Spent Motor Engine Oil Using Acidified Clay

Abstract: This research is centered on the purification of Spent Shell Helix (HX3 20W-50) lubricating oil using acidified clay treatment with three acids options: mineral sulfuric acid (H2SO4), organic acetic acid (CH3COOH), and organic citric acid (C6H8O7), (a novel washing agent). The clay mineral, spent, purified, and fresh lubrication oil samples were characterized to determine their physicochemical properties. The clay mineral was characterized using Energy-Dispersive X-Ray Fluorescence (EDXRF). The result indicated that the clay was bentonite clay and it was successfully acidified. The result also indicated that properties of the spent lubricating oil such as Kinematic viscosities at 40 oC and 100 oC increased from 118.9 cSt and 13.9 cSt for the spent oil to 169.7 cSt and 15.2 cSt, 178.2 cSt and 16.3 cSt, 183.4 cSt and 16.8 cSt for the oil samples purified with C6H8O7, CH3COOH and H2SO4 respectively Also, the flash point increased from 106 oC for the spent oil to 133 oC, 180 oC, 189 oC for the oil samples purified with C6H8O7, CH3COOH and H2SO4 respectively. The FTIR analysis of the spent oil revealed the presence of primary oxidized products, absent in spent engine oil purified with mineral sulphuric acid (H2SO4), organic acetic acid (CH3COOH), and fresh oil. Acidified clay effectively purified the spent engine oil, bringing its physicochemical properties closer to those of fresh oil. However, the effectiveness of the treatment varied depending on the specific acid used.

Evaluation of Some Potentially Toxic Elements and Associated Ecological and Health Risks in Topsoil Samples Adjacent to an Industrial Zone in Turkey.

Potentially toxic element (PTE) pollution as a result of industrial activities remains a global problem that poses serious threats to human and ecological health. PTEs (Al, Fe, Ti, Mn, V, Zn, Cu, Cr, Ni, Pb, Co, and As) are metals or metalloids with biological toxicity. This study analyzed the concentrations of these PTEs and the physicochemical properties of topsoil samples collected from areas near industrial districts in the Samsun province of Turkey to evaluate ecological and health risks, estimating various indexes. The average concentrations of Al, Fe, Ti, Mn, V, Zn, Cu, Cr, Ni, Pb, Co, and As analyzed in 23 topsoil samples by energy-dispersive X-ray fluorescence spectrometry were found as 93,822, 82,410, 6623, 1642, 406, 278, 207, 149, 78, 68, 32, and 10 mg/kg dry weight, respectively. Zn, Cu, Cr, Ni, Pb, and Co levels exceed the maximum contaminant levels in the Turkish Regulation on the Control of Soil Pollution. The average pH values, organic matter, total organic carbon, and nitrogen measured in soil samples were 7.14, 6.11, 0.96, and 0.04%, respectively. The ecological and health evaluation reveals that the studied area is polluted with V, Cu, Zn, As, Ni, and Pb, which may pose a risk to people living in settlements near the industrial district.

Microstructures and properties of a novel cemented carbide prepared using a Co–Ni–Cu multiprincipal element alloy as the binder

A Co–Ni–Cu multiprincipal element alloy (MPEA) powder was successfully synthesized through coprecipitation. Results of energy dispersive spectroscopy (EDS) and X-ray fluorescence spectroscopy (XRF) revealed nearly equal atomic ratios for Co, Ni, and Cu in the Co–Ni–Cu MPEA powder. Moreover, X-ray diffraction (XRD) confirmed a single-phase face-centered cubic (fcc) structure in the Co–Ni–Cu MPEA powder. To explore the differences in microstructure and mechanical properties, we compared a novel WC–2Co–2Ni–2Cu cemented carbide, utilizing the Co–Ni–Cu MPEA as a binder, with conventional WC–6Co and WC–3Co–3Ni cemented carbides prepared via liquid phase sintering. This comparison was conducted using scanning electron microscopy, XRD, and mechanical properties testing. Observations revealed that the surfaces of WC grains in WC–2Co–2Ni–2Cu and WC–6Co appeared smooth and flat, while those in WC–3Co–3Ni exhibited roughness with numerous terraces. In addition, the average grain size was 0.96, 1.14, and 1.22 μm in WC–2Co–2Ni–2Cu, WC–6Co, and WC–3Co–3Ni, respectively. Notably, the Co–Ni–Cu MPEA inhibited WC grain growth. WC–2Co–2Ni–2Cu (1388 HV30) exhibited hardness similar to that of WC–6Co (1406 HV30) but the highest fracture toughness (9.04 MPa∙m1/2), while WC–3Co–3Ni (1332 HV30) presented the lowest hardness. Bending strength values were recorded at 2406 MPa for WC–2Co–2Ni–2Cu, 2816 MPa for WC–6Co, and 2645 MPa for WC–3Co–3Ni, with WC–6Co exhibiting the highest bending strength. Considering their microstructures, physical properties, and mechanical properties comprehensively, the novel cemented carbides exhibited only slightly reduced bending strength compared to conventional counterparts. Thus, the Co–Ni–Cu MPEA binder demonstrates promising potential as a replacement for the conventional Co metal binder.

Analytical Techniques for Detecting Rare Earth Elements in Geological Ores: Laser-Induced Breakdown Spectroscopy (LIBS), MFA-LIBS, Thermal LIBS, Laser Ablation Time-of-Flight Mass Spectrometry, Energy-Dispersive X-ray Spectroscopy, Energy-Dispersive X-ray Fluorescence Spectrometer, and Inductively Coupled Plasma Optical Emission Spectroscopy

Rare earth elements (REEs) hold significant industrial, scientific, and modern technological worth. This study focused on detecting and quantifying REEs in various geological ore samples. These samples were collected from different REE-bearing locations recommended by geological experts. The analysis was conducted using laser-induced breakdown spectroscopy (LIBS) and laser ablation time-of-flight mass spectrometry (LA-TOF-MS). In this work, LIBS methodology was employed using three different configurations: standard LIBS, LIBS with an applied magnetic field, and LIBS with both an applied magnetic field and target sample heating within an optimal temperature range. Elements from the REE group, specifically lanthanum (La), cerium (Ce), and neodymium (Nd), were identified and quantified. To detect, quantify, and validate the results from LIBS and LA-TOF-MS, we utilized an array of analytical techniques—Energy-Dispersive X-ray Spectroscopy (EDX), Energy-Dispersive X-ray Fluorescence Spectrometer (ED-XRF), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Interestingly, the quantitative results for REEs (La, Ce, and Nd) in the ore samples obtained using the LIBS technique with various configurations were found to be in agreement with those from LA-TOF-MS, EDX, XRF, and ICP-OES. In addition, LIBS enables detailed microchemical imaging, allowing the map of the spatial distribution of elements within the mineral–ore matrix. The high-resolution microscale elemental mapping of REEs was accomplished using the emission lines Ce (II) at 446.0 nm, La (II) at 492.1 nm, and Nd (II) at 388.8 nm. By integrating multiple analytical techniques, our study enabled the construction of a complete elemental distribution map, providing new insights into the geochemical processes and mineral composition of rare earth ores, while advancing geochemistry and contributing valuable data for rare earth resource exploration.

Diffraction peak identification and correction in EDXRF spectroscopy

Energy dispersive X-ray fluorescence (EDXRF) spectroscopy is an analytical technique often used to create maps of the elemental chemical composition. The fluorescence signal can be influenced by x-ray diffraction peaks, a phenomenon that can lead to difficulties or errors in interpreting spectral peaks. However, diffraction can also be useful if we successfully separate it from the fluorescence signal. In this paper, we propose different methods to deal with the diffraction peaks by using the signals obtained from a spectrometer equipped with two detectors. These methods were tested on a thin section of a rock sample to show their effectiveness in processing diffraction peaks. Each method showed its ability to deal with the diffraction peaks in a more or less effective way and each has its own limitations. The latter have to be taken into account when analyzing the EDXRF signal, whether in a geological context or in any other context.

Characterization of Mn3O4/(x)Nb2O5 thin films as a promising material for supercapacitors

The thin films of Mn3O4/(x)Nb2O5 oxides (x = 0, 2, 4, and 6 %) were prepared by the electron beam evaporation method and then annealed at 400 °C. The structural analysis showed a tetragonal phase of Mn3O4, according to X-ray diffraction results. The quantitative elemental analysis of films confirms the stoichiometry of the Mn3O4, while the Nb2O5 couldn’t be recognized using energy dispersive X-ray fluorescence. The chemical speciation of the films was investigated using X-ray photoelectron spectroscopy. Three oxidation states of Mn were recognized at average binding energies of 645.70±0.35, 642.99±0.40, and 641.58±0.48 eV that correlated to Mn4+, Mn3+, and Mn2+, respectively. As the Nb2O5 increases, a slight decrease in the binding energy of Mn4+ is recognized, whereas it is nearly constant for the deconvoluted Mn3+ and Mn2+. Two electronic transitions (Eg1 and Eg2) of the optical band gap showed an increase with increasing Nb2O5 dopant from 2 % to 6 %. The optical parameters such as Eosc, the single oscillator energy, Edis, the dispersion energy, both moments (M−1) and (M−3), the ratio of carrier concentration/effective mass (N/m*), and the lattice dielectric constant (εL) were determined. From electrochemical measurements of pure Mn3O4 films, it is found that the voltammetric current density is directly proportional to the scan rates of cyclic voltammetry CV, with good cyclic stability, and by increasing the scan rates, the values of specific capacitance decrease while the values of specific power increase. In doped thin films, no potential drop is observed in the discharging process, which indicates good interfacial contact between the active material and the substrate during the charge/discharge process. These results suggest that the obtained Mn3O4 nanoparticles are a better candidate for supercapacitor applications.

Using optimized monochromatic energy dispersive X-ray fluorescence to determine the cadmium concentration in cacao and soil samples

Following the implementation of food safety limits on cadmium (Cd) in cacao products, there has been a growing demand for monitoring Cd in cacao tissues and soils. Traditional methods like acid digestion followed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are time-consuming and costly. X-ray Fluorescence is an alternative technique that offers advantages in terms of speed, cost, ease of use and less environmental impact. However, to date, relatively high detection limits have impeded its application for food safety limits. This study examines a Monochromatic Energy Dispersive X-ray Fluorescence (MEDXRF) method optimized for Cd analysis as an alternative to ICP-MS. Using a measurement time of 200 s, the average limit of quantification (LOQ) was 0.178 mg Cd kg−1 for biological samples and 0.205 mg Cd kg−1 for soil samples. A strong correlation (y = 1.013 x + 0.003, R2 = 0.984) with ICP-MS results was found for 95 bean, 16 cacao liquor, 75 leaf, and 91 soil samples. The coefficient of variation (CV) among three replicates was below the threshold value of 15 % for most samples with Cd concentrations above the reported LOQ values. Additionally, a significant difference in CV was obtained between soils sieved over 500 μm (median 8.2 %) or 2 mm (median 9.8 %). However, no significant difference in CV was observed between 500 μm unpeeled beans and cocoa liquor with particle size of 20 μm. Based on our data, the proposed procedure is to analyze three replicates for 200 s with a sample size of 500 μm. The optimized MEDXRF technique offers important advantages in terms of cost-effectiveness and efficiency of routine Cd monitoring in the cacao supply chain, large-scale screening, and scientific research, and could be extended to other crops and heavy metals that are subject to food safety regulation at low concentrations.

Chromogenic mechanisms of overglaze yellow pigment produced in Jingdezhen imperial kilns during the Ming dynasty

This study employed energy-dispersive X-ray fluorescence spectrometry, Raman spectroscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible-near infrared spectrophotometry to analyse eleven overglaze pigment porcelain specimens. The results show that the colouring element of the overglaze yellow pigment of Jingdezhen imperial kilns in the Ming dynasty is Fe2O3, and most of Fe2O3 can be dissolved in the lead glaze in an ionic state to make the lead glaze yellow. The chromogenic of the overglazed yellow pigment primarily depends on the concentration and coordination field of the colouring ions. The connection between the internal structure and the appearance of the overglaze yellow pigment is discussed.

Bismuth-gold nanohybrid based nano photosensitizer to combat antimicrobial resistance

Antimicrobial resistance (AMR) leads to a decrease in the adequacy of antimicrobial agents and an increase in the rate of adverse effects and mortality. The main objective of this project is to investigate the synergistic effect of BiAu@NCLin-T1 and its substructures as an antimicrobial photodynamic therapy (aPDT) agent to combat microbial resistance. In addition, the effect of photothermal therapy (PTT) on some of the designed nanostructures at a temperature of 40 °C was also tested. The antimicrobial test was carried out using the growth curve method against Escherichia coli and Staphylococcus aureus. Computational methods were used to investigate the stability and entropy of oligonucleotide sequence structures. Various analyses were performed to identify the nanostructures, including Ultraviolet–visible (UV–vis) spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and fluorescence analysis. The BiAu@NCLin-T1 appeared the significant aPDT impact against the gram-negative E.coli strain at two distinctive oligonucleotide concentrations (1, and 1.5 micromolar (µM)). Based on the results, the outlined nanostructures can act as a photosensitizer (PS), a photothermal treatment (PTT) agent, and an antimicrobial agent to combat resistant bacteria.

Различные формы Sr в агротемногумусовых подбелах юга Приморского края

To assess the concentration level and identify the main phase-carriers of various forms of strontium (Sr), the total content, distribution and concentration of water-soluble forms of the element in Albic Stagnosoils, which composed the bulk of the arable fund of the region under study, were studied. Full-profile soil pits were dug at the long-term fallow, phytoreclamative, and fertilized with mineral and organic fertilizer variants of the experience. The study of the different Sr forms contents was carried out by energy dispersive X-ray fluorescence spectroscopy and atomic absorption spectrometry. The main Sr volume was immobilized in the composition of soil mineral phase in soils of all variants of the experience. The addition of mineral fertilizers to soil was accompanied by an increase in the total content (by 6.4 %) and concentration of water-soluble (by 5,7 times) Sr forms, compared to the soil of fallow, and intensification of Sr sorption by Mn-containing soil compounds. The long-term addition of different types of organic fertilizers contributed to the activation of stable Sr-organic complexes formation. Under a green manure application in conditions of soil solution acidity decrease, the increase in the influence of Ca-containing soil compounds on the distribution of Sr has been shown. The soils of all variants of the experience were characterized by the absence of factors and conditions that contributed to the Sr accumulation in profiles, it was suggested by the lower total Sr content compared to the mean background content for surface soils around the world and to the mean content in agricultural soils in Japan.

Valorization potentials of phosphate tailings at Minjingu mines in Northern Tanzania

Sedimentary and igneous rocks are the two primary sources of phosphate that are mined and beneficiated to fertilizer. During the beneficiation process, phosphate is lost into the tailings. We investigated phosphate concentrations in tailings dumps at Minjingu mine, Tanzania using energy-dispersive X-ray fluorescence spectrometry to quantify the chemical compositions. The phosphate content in the tailings varied from 12.91% phosphorus pentoxide (P2O5) in Tailings 2 to 19.61% in Tailings Dump 1. The naturally occurring phosphate concentration in rocks ranges from 3% to 35%, and phosphate tailings from various locations with P2O5 concentrations as low as 6.46-12.65% have been beneficiated to commercial fertilizer. Our investigation revealed that phosphate concentrations in Minjingu tailings may be sufficient to be recovered for commercial applications. Suitable recovery methods are discussed, and we recommend that beneficiation should be performed to minimize the loss of phosphate into tailings. Further research is needed to identify the optimal beneficiation methodology.

TiO2 nanotubes zeolite nanophotocatalyst performance efficacy toward the photocatalytic degradation of triclocarban in bathroom greywater

Triclocarban (TCC) is persistent in aquatic environments, where it can remain stable for extended periods. It can cause long-term exposure, potentially affecting ecosystems and human health through contaminated fish or water. Therefore, this study aims to investigate the degradation of TCC in bathroom greywater by the application of TiO2 nanotubes coated with zeolite (TNZPC) in photocatalytic degradation. Electrochemical anodization (ECA) and electrophoretic deposition (EPD) were applied to form TNZPC. Field Emission-Scanning Electron Microscopy (FESEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), and X-ray Fluorescence (XRF) verified the characterization of TNZPC accordingly and the degradation kinetics of TCC followed the pseudo-first-order model of Hinshelwood. The highest degradation rate, reaching 95.2%, was observed at pH 11, while the lowest rate was at pH 3, with a degradation efficiency of only 72.6% after 60 minutes of irradiation with utilization of 0.75 cm2 of TNZPC. The mechanism study has verified eleven intermediate products were produced during TCC degradation by the process of oxidation, ozonation, hydroxyl radical (*OH), and dichlorination. The study suggests that finding the optimum conditions such as photocatalyst modification, cationic material, light sources, TCC initial concentration, pH, and TNZPC size play crucial roles in significant TCC photocatalytic degradation.