XRF Results Research Articles

Utilization of circulating fluidized bed coal ash in autoclaved aerated concrete manufacture by mineral carbonation

Using circulating fluidized bed combustion (CFBC) ash discharged from thermal power plants, we identified factors affecting mineral carbonation to sequester CO2 and produced autoclaved aerated concrete (AAC). To use CFBC ash as a raw material for AAC, free-CaO, which causes volume expansion, was replaced through hydration and carbonation. During the raw material replacement process, carbonation behavior was confirmed through pH and temperature. A Ca(OH)2 to liquid ratio similar to a fly ash to liquid ratio of 0.25 is considered to provide sufficient diffusion distance, and the reaction rate may increase due to the rise in water temperature caused by Ca2+ leaching. Additionally, the results of XRD, XRF, TG-DTA, and SEM analyses indicate that hydration and carbonation reactions were stably achieved in the materials, suggesting that CO2 sequestration allows the materials to be used as alternative raw materials. After identifying the characteristics of the CFBC ash and the substituted material, AAC was manufactured through pressurized carbonation. The weight change rate, carbonation depth, ventilation rate, pore structure, and compressive strength of the manufactured AAC were measured. As a result, the alternative raw material exhibited higher permeability and a larger pore size range in the specimens compared to the original material, indicating easier CO2 penetration into the specimens. Consequently, this experiment suggests the potential of using the material in AAC production by providing a theoretical basis for solving volume expansion issues associated with concrete admixtures and CO2 sequestration in waste materials.

Hydrothermal synthesis of tetragonal FeS: Dome-shaped superconductivity vs Fe:S actual molar ratios

We successfully synthesized tetragonal FeS with various Fe:S molar ratios using a hydrothermal method, and the EDS and XRF results confirmed that FeS exhibits superconductivity within the Fe and S element ratio range of 1.155–1.274, rather than a strict stoichiometric ratio. The reaction temperature can not only play a crucial role in determining the purity of the obtained FeS phase but also significantly alter its micromorphology. Significantly, by analyzing the relationship between the Fe:S actual molar ratio and Tc as well as the Fe:S actual molar ratio and unit cell volume, FeS exhibits dome-shaped superconductivity and shows a negative correlation with Tc and chemical pressure. Furthermore, considering the correlation between anion height (hanion) and Tc, Tc reaches the maximum value of 4.53 K for hanion ≈ 1.28 Å, a behavior distinct from that of observed in Fe-pnictide superconductors. In short, our experimental results provide a unique perspective to deepen our understanding of FeS superconductors.

Identification and distribution of fluoride in Singkep Island, Lingga Regency, Riau Islands

The consumption of fluoride below the safe limit can result in dental caries, while high concentrations can lead to fluorosis, which can potentially impair the body's systems. One geological factor that influences the concentration of fluoride in water is the type of rock through which the water passes, including granite and its weathering products. The area is located within the Tandjungbuku Formation, which is predominantly composed of granite rock and contains several areas with Mining Business Permits (IUP) for commodities such as silica sand. This research serves as a form of mitigation in response to mining activities, post-mining, and the development of an industrial area. One anticipated impact is an increase in fluoride concentration in the research area, originating from both natural geological processes and human activities. The investigation involved geological mapping, petrographic analysis, XRD, and XRF analysis. Water sampling was conducted for both surface water and groundwater from wells in Resang Tandjungbuku Village. The research area consists of two rock units: granite, which acts as a non-aquifer layer, and colluvial deposits, which function as a free aquifer. Petrographic analysis identified minerals associated with fluoride, such as plagioclase, amphibole, and biotite. This was supported by XRD analysis with the presence of biotite, muscovite and kaoline minerals. XRF results revealed fluoride values in granite rock at 0.23% or 2300 ppm, further confirming granite as a source of fluoride. Analysis of fluoride in surface water showed values ranging from 0.01 to 4.24 mg/L, while groundwater consistently had a value of 0.01 mg/L.

Application of some calibration strategies in comparison to determine Cr, Ni, Cu, Zn, As, and Pb in contaminated plants by wavelength dispersive x‐ray fluorescence

AbstractThe study of nonstandard samples wherein their element compositions differ from those of routine samples motivates analysts to look for new methodological approaches. To determine the high concentrations of Cr, Ni, Cu, Zn, As, and Pb in polluted plants, the authors applied wavelength dispersive x‐ray fluorescence (WDXRF), using three calibration strategies in comparison. The following sets of calibration samples were tested: available plant and biological CRMs; synthetic samples; and “house reference materials” (HRMs). The synthetic samples were prepared, adding small portions of the loose sediment CRMs to a plant CRM. The polluted plant samples, analyzed by atomic absorption spectrometry and inductively coupled plasma mass spectrometry, were used as HRMs to construct the calibration curves and validate XRF results. It was ascertained that all three calibration strategies can be used to quantify above elements in contaminated plants, providing different precision of WDXRF results. The calibration procedure with HRMs has provided the least errors in the element determinations. Calibration with synthetic samples causes larger errors due to some differences in chemical compositions between calibration and analyzed samples as well as due to probable errors in the synthetic sample preparation. The calibration with plant and biological samples is of limited applicability in XRF of contaminated plants by reason of narrow content ranges of some elements.

Investigation of the use of Botswana coal fly ash as a material for the adsorption of arsenic from fortified water

<p>The main objective of the study was to characterize raw (RFA), water-washed (WFA) and iron-modified (Fe-WFA) Botswana coal fly ash to determine the physical and chemical properties as well as investigate its potential use as adsorbents for the removal of arsenic(III) ((As(III)) from fortified water. Scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS) showed particles with irregular size and shape for all the materials and porous iron oxide flakes for Fe-WFA. The SEM-EDS, X-ray diffraction analysis (XRD) and X-ray photoelectron spectroscopy (XPS) showed the main constituents of RFA, WFA and Fe-WFA to be SiO<sub>2</sub>, Fe<sub>2</sub>O<sub>3</sub>, Al<sub>2</sub>O<sub>3</sub> and CaO. The XPS further showed the surface composition of Fe-WFA with higher Fe content at 19.7% compared to 0.8% and 1.2% for RFA and WFA respectively. The XRF and XRD results confirmed the successful modification of WFA with iron by showing the Fe<sub>2</sub>O<sub>3</sub> composition increasing from 12.6% of WFA to 25.5% for Fe-WFA. The inductively coupled plasma-mass spectrometry (ICP-MS) results showed continuous reduction of metal concentrations for WFA and Fe-WFA from the first to the sixth wash. The adsorption of As(III) on the adsorbents followed the Freundlich adsorption model. The maximum adsorption capacities of 0.85, 0.02 and 2.26 mgg<sup>−1</sup> were obtained for RFA, WFA and Fe-WFA respectively.<strong></strong></p>

The Characteristics of Polyester Concrete with Local Sand of East Borneo as Filter

Concrete is a mixture of coarse aggregate and fine aggregate mixed with water and cement as a binder and filler. The disadvantages of traditional concrete are that high water absorption causes low chemical resistance, low modulus of elasticity, low impact strength and a long hardening time to reach its maximum properties, namely 28 days. The solution to these shortcomings that is being developed for construction material applications is by using polymers as polymer concrete. In this research, polyester resin and sand aggregate were used as basic materials. Polyester resin is a type of thermosetting polymer that is widely used in various applications such as automotive parts, composites and construction because of its suitable processing characteristics and affordable price. Meanwhile, the sand used is local Kalimantan sand, where from the XRF and XRD test results, local Kalimantan sand is included in the silica sand type. This research varies the weight fraction of polyester resin used to determine its effect on polymer concrete characteristics such as porosity, water absorption, compressive strength, and macro observations. Variations in the polymer weight fraction used were 20%, 25% and 30%. Compressive strength testing was carried out at the age of 7 days of concrete. The results of the porosity test show that the average porosity of all variations is ± 0.5%. Meanwhile, the average value of water absorption for all fractions is 0.2%. And the highest average value of compressive strength in the 30% polyester resin weight fraction was 66.9 MPa. So it can be concluded that all variations meet SNI standards to become concrete materials.

THE ROLE OF ATOMIC SCATTERING FACTORS IN DETERMINING THE MINERAL COMPOSITION OF THE BAZHENOV SUITE'S ROCKS

For the first time, it was demonstrated, that the use of standard atomic-structural parameters of minerals in X-ray diffraction (XRD) analysis to determine the phase composition in the Bazhenov suite's core is incorrect and most often leads to inaccurate information when calculating their quantitative ratio. In particular, by decomposing the XRD — based quantitative data on the mineral composition of the core of the Bazhenov suite into the main rock-forming oxides and further comparing them with reliable X-ray fluorescence spectrometry (XRF) data, an unsatisfactory convergence between them was established. At the same time, significant differences in the results of XRD and XRF have been shown in terms of oxides of silicon, sodium, magnesium, potassium, and iron, both at large and small mass fractions. It has been found that even with perfect XRD, achieved by optimizing the standard mineral structure parameters (lattice period, crystallite size, crystal lattice microdistortion, absorption coefficient, crystallographic texture, background) and achieving a very high degree of convergence (more than 95%) of experimental and theoretical diffractograms, the differences between oxide forms are still significant. It is shown, that the results of XRD of Bazhenov suite are questioned due to detected inconsistencies in oxide forms. Using the analysis of multiple factors and data from diffractograms of many samples, it has been established that the identified differences are primarily caused by the use of incorrect initial atomic-structure parameters of minerals in modeling. It is shown that rock minerals in the Bazhenov suite are primarily characterized by significant changes in the values of atomic scattering factors and significant displacements of atomic positions in the nodes of the crystal lattice, caused by the action of the high pressures and temperatures in the formation. For the first time, the XRD algorithm that has been developed, is presented and implemented in Bazhenov suite rocks, with consideration of the state of atoms in the analyzed mineral. Furthermore, it was found that the authors XRD approach enables the identification and quantification of the Bazhenov suite minerals with a relatively low content, which are challenging to identify during traditional XRD.

Chemical and physical activation of natural pyrite as potential inorganic pigment material

Pyrite is one of the minerals in Borneo Island. It has a disadvantage for soil quality due to its acidity properties. One of the main components of pyrite is iron, which promises to be utilized as an inorganic pigment. This research aims to transform pyrite into red-brown pigment material-based iron oxide. Pyrite mineral transformation through chemical and physical activation, followed by pigment characterization using XRF, XRD, FTIR, and FE-SEM. Based on the XRF result, the highest component is Fe, with a percentage up to 42%. This data is also suitable with an iron oxide phase from the diffractogram of pigment, followed by silica and alumina structure. The heating process successfully changed the color materials from gold to red-brown. Then, the molecular vibration of Fe–O also appears on FTIR spectra at a wavenumber of 483 cm-1 and T–O–T bending at 994 cm-1. Moreover, morphological observation exhibits the aggregation of particles and distribution of iron element spread on the overall area pigment. The color transformation into red-brown pigment can be obtained by pyrite processing into potential inorganic pigment material.

Analysis of the properties of chemical content and the use of local material Kinang Jingkion as coarse aggregate against the characteristics of WC last (AC) mixture in Yalimo Regency

This study aims to analyze the nature of chemical content, analyze abrasion value and optimum asphalt content using local Kinang Jingkion as road pavement material. In this study, XRF and XRD testing methods were used to determine the chemical content of Kinang Jingkion local material, then testing the characteristics of rough aggregate to determine the abrasion value, testing fine aggregate characteristics, and testing asphalt pen 60/70 and marshall test to determine the optimum asphalt content (KAO). The tests obtained the results of comparative data analysis between laboratory tests and literature standards that meet the eligibility requirements. The results showed that: First, the results of XRF and XRD analysis on Wilihingke samples, 0.15 mm granules, 2.36 mm granules, and Kinang Holuwon found that all chemical elements contained in the four samples were solid metal inorganic chemical elements. The results of this analysis prove that the four samples, which are fine aggregates and coarse aggregates, do not contain organic substances. Where the results of this analysis are by the requirements of aggregates which are one of the components in the concrete mixture, where the aggregates used must meet certain conditions, one of which must not contain excess organic matter because it can undergo decay by bacteria using dissolved oxygen; Second, from the test results obtained, the aggregate wear value (abrasion) was 32.69%; Third, based on the test results, the value of the Marshall parameter with Optimum Asphalt Content (KAO) obtained a value of 6.125%.

Synthesis of geopolymer powder and beads based on red clay waste for the adsorption of methyl orange dye from aqueous solutions: Characterization, application of response surface methodology, and cost analysis

The current research focuses on the valorization of red clay waste (RCW) to develop alumino-silicate geopolymer binders (GPP) and geopolymer spheres obtained from GPP powder modified with sodium alginate (Alg/GPP). GPP and Alg/GPP were applied in the environmental field for the retention of methyl orange (MO) from an aqueous solution. The raw material and the synthesized geopolymers were characterized by various physico-chemical methods. The results of XRF, XRD, and FTIR confirmed the successful synthesis of GPP and Alg/GPP, while the SEM/EDX findings revealed the homogeneous surface of the adsorbents. A significant specific surface area was detected for GPP (73.56 m2/g) and Alg/GPP (91.24 m2/g) with a high cation exchange capacity around 122 meq/100g for GPP and 185 meq/100g for Alg/GPP. The removal process was performed using the response surface methodology according to the Box-Behnken design, optimizing the retention efficiency of MO by different factors, including temperature, initial concentration, solution pH, and contact time. The obtained data was treated through the analysis of variance (ANOVA) and fitted by a quadratic polynomial model based on multiple regression analysis. In an acidic medium at 45 °C, the optimal conditions for MO retention were estimated to be 120 mg/L of MO concentration in 55 min using GPP and 180 mg/L of MO concentration in 20 min using Alg/GPP. The pseudo-second-order kinetics were more appropriate for describing the MO removal onto GPP and Alg/GPP adsorbents. The Langmuir model identified a high retention capacity of MO around 94.78 mg/g via GPP and 224.85 mg/g via Alg/GPP. The thermodynamic data confirmed that the elimination of MO dye onto GPP and Alg/GPP adsorbents was endothermic, favorable, and spontaneous. This study provided insights into the valorization of composite materials based on solid waste in dye retention, which can potentially be employed in wastewater treatment.

Silver Recovery from E-Waste Printed Circuit Board Using Binary and Ternary Deep Eutectic Solvents

Printed Circuit Boards (PCBs) are essential components of electronic devices containing valuable silver metal. Using sustainable methods, silver recovery from electronic trash, like PCBs, demonstrates excellent promise. This research’s objective is to determine the optimum leaching time and solid-to-liquid (S/L) ratio for extracting silver from PCB using deep eutectic solvent (DES) composed of choline chloride and glycerol (glyceline DES). The binary DES’s leaching performance was then compared to choline chloride, glycerol, and citric acid ternary systems. Fourier Transform Infrared Spectroscopy (FTIR) was carried out to analyze the bond interactions. X-ray fluorescence spectrometry (XRF) was employed to determine the PCB’s metal concentration prior to and after the leaching process. Ternary DES was viscous, colorless, stable for 60 days, and less acidic than binary DES, with a 1.21 g/mL density. FTIR peak broadening and shifting indicated the formation of a new hydrogen bond and proved a successful synthesis of ternary DES. XRF result showed that PCB’s initial silver metal content was 2.32%. The optimal silver leaching from PCB using glyceline DES was achieved after 16 hours, with a 1/20 solid-to-liquid ratio. Ternary DES demonstrated a silver leaching efficiency of 93.65%, surpassing 86.77% of glyceline. Ternary DES synthesized in this study has the potential to serve as an efficient and environmentally friendly solvent for extracting silver from PCB, providing a sustainable approach to managing electronic waste.

Accumulation, Bioavailability, and Health Risk of Heavy Metals in Some Plants Obtained from Abu-Ghraib Land, Baghdad, Iraq

The study of the distribution of major oxides and heavy metals in some plants collecting and analyzing eighteen plant samples of vegetables including carrot, onion, eggplant, cucumber, and okra obtained from Abu Ghraib land located about 20 km west of Baghdad, Iraq. Eighteen plant samples of vegetables,.Heavy metals can have a severe impact if released into the environment, even in trace quantities. These can enter the food chain from aquatic and agricultural ecosystems and indirectly threaten human health.. Trace elements and oxides of As, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Se, Th, U, V, and Zn were measured in plant samples using an X-Ray Fluorescence Instrument (XRF). TEs analyses of vegetables were performed in the Iraqi German Laboratory in the Department of Geology, University of Baghdad. The results of XRF indicated that the highest Mean ± SD concentrations of As, Cr, Mo, Cu, Ni, Pb, Se, V and Zn were 5.24 ± 1.846, 229.436 ± 53.598, 12.97 ± 3.95, 69.128 ± 60.577, 87.14 ± 56.711, 18.826 ± 7.572, 0.5 ± 0, 88.506 ± 5.902 and 236.25 ± 227.55 ppm in carrot. Eggplant exhibited the highest concentration of Mn and U, which was 56.923 ± 39.584 and 1.76 ± 1.81 ppm, respectively. However, the total hazard quotient (THQ) of the investigated elements indicated that their levels have no potential to cause a risk to consumers’ health, except Cr (THQ >1), which was higher in all plant samples. This study suggests the safety of vegetables (carrot, onion, eggplant, cucumber, and okra) harvested from farms in Abu-Ghraib, Baghdad, and their low risk of inducing serious health events and raises a concern of the elevated levels of Cr, which necessitate innovative methods to decrease its risk.

Phosphorus removal of coal-based bottom ash: Performance evaluation and mechanism exploration

In this paper, the phosphorus removal efficiency and capability and pore structure and composition of coal-based bottom ash before and after phosphorus removal are studied to reveal the phosphorus removal mechanism. The results show that the phosphorus removal rate of bottom ash increases with the increase of pH value; When the pH value is 8, the phosphorus removal rate can reach more than 95%. The highest desorption rate is only 2.42% and the pseudo-second order model can be better fitted with the phosphorus removal process of bottom ash, indicating chemical adsorption is the control mechanism. The maximum phosphorus removal capacity is 5.54 mg/g. After phosphorus removal the fractal dimension and porosity decrease, and the specific surface area increases, indicating that the complexity of the pore structure decreases, and the roughness of the pore wall increases. The characteristic peak of brushite (CaHPO4·2H2O) in the XRD spectrum and HPO42− at 2362 cm−1, 985 cm−1 and 800-650 cm−1 appear, respectively. In the XRF results, P2O5/SiO2 ratio increases from 0.008 to 0.089, but SO3/SiO2 ratio decreases from 0.047 to 0.027. The phosphorus removal mechanism of coal-based bottom ash lies in its complex pore structure and the precipitation reaction between soluble Ca2+ and HPO4− in the sewage.

Development of an antimicrobial and antifouling PES membrane with ZnO/poly(hexamethylene biguanide) nanocomposites incorporation

Although polyethersulfone (PES) membranes are extensively utilized in water and wastewater treatment, they typically encounter serious bio/organic fouling problems. In this work, an antimicrobial and antifouling PES membrane was developed through incorporating novel ZnO/PHMB (zinc oxide/ polyhexamethylene biguanide hydrochloride) nanocomposites on the surface of a commercial PES membrane, with PDA (polydopamine) serving as an intermediate connection layer. XPS, along with synchrotron-based XRF and ATR-FTIR results confirmed the successful synthesis of the ZnO/PHMB nanocomposites and ZnO/PHMB membranes. The ZnO/PHMB nanocomposites exhibited an impressive antimicrobial rate of 99.99 % with a minimal amount of PHMB addition (wtZnO:wtPHMB = 1:0.01). The concentration of the ZnO/PHMB nanocomposites had the most significant impact on the antimicrobial performance of the ZnO/PHMB membrane. The 600ZP membrane (i.e., the PES membrane modified with 600 mg/L ZnO/PHMB nanocomposites) emerged as the optimal choice, as evidenced by its commendable antimicrobial performance (92.80 %), water flux (249.02 LMH), RB (Rose Bengal sodium salt) rejection (93.96 %), and cost-benefit considerations. Compared to the pristine PES membrane, the 600ZP membrane showed 5.32 %, 15.76 %, and 7.62 % increased hydrophilicity, water flux, and RB rejection rate, respectively. Additionally, the 600ZP membrane possessed a bactericidal rate of 92.80 % and a flux recovery rate of 89.24 % after three cycles of SA (sodium alginate) filtration, indicating enhanced antimicrobial and antifouling capacities. The 600ZP membrane exhibited a remarkable 91.05 % higher water flux following prolonged (72 h) treatment of secondary effluent, compared to the PES membrane. Attribute to the increased hydrophilicity, outstanding antimicrobial activity, as well as excellent stability and durability, the as-prepared ZnO/PHMB membrane shows great potential for wastewater treatment.

Catalytic upgrading of palm oil derived bio-crude oil for bio-hydrocarbon enrichment using protonated zeolite-Y as catalyst

<abstract> <p>This research was conducted to study upgrading bio-crude oil (BCO) produced by pyrolysis of palm oil without the use of a catalyst, using protonated zeolite-Y designated as H-Y. Preparation of H-Y was carried out by subjecting zeolite-Y synthesized from rice husk silica (RHS) and food grade aluminium foil (FGAF) to a cation exchange process using ammonium nitrate solution with different concentrations of 2.0, 2.5, 3.0, and 3.5 M to obtain (H-Y) samples with different protonation extents. To confirm the formation of Na-Y, the sample was characterized using XRD and SEM, and to evaluate the protonation, the Na-Y and H-Y samples were analyzed using XRF. Characterization using XRD showed that the Na-Y sample is faujasite, which is the characteristic phase of zeolite-Y, and supported by the existence of particles with octahedral structure as seen by SEM. Successful protonation resulted in a reduction of Na content up to 89.948% from that of the Na-Y, which was demonstrated by the XRF results. Catalytic upgrading experiments demonstrated that H-Y zeolites functioned to increase the bio-hydrocarbon content from 80.23% in the BCO to practically 100% in the upgraded oil. In addition, no acids were identified in the upgraded fuels, implying that H-Y zeolite is a promising catalyst for BCO upgrading for bio-hydrocarbon enrichment of the oil.</p> </abstract>

Distribution of silicon in different organ of bamboo (Gigantochloa apus (Schult. & Schult.) Kubz ex Munro)

Bamboo is one of the plants that accumulates large amounts of silicon (Si) and potentially be utilized as a source of Si. Si plays a role in reducing abiotic and biotic stresses. This study aims to analyze the Si content in ash from various bamboo plant organs (leaves, stems and roots). Bamboo was taken from Klaten Regency, Central Java. The process of making ash used manual burning, followed by ashing using a furnace at 600 °C in temperature. Bamboo plant ash was analyzed using the AOAC method and confirmed by Energy Dispersive X-Ray Fluorescence Spectrometer (ED XRF), Scanning Electron Microscope (SEM) instruments and mapping to determine the composition of the oxide and SiO2 content. Analysis using the AOAC method showed that SiO2 content in bamboo leaf ash (76.88%) was higher than bamboo stem ash (48.43%) and bamboo root ash (56.28%). The results of ED XRF, SEM analysis and mapping showed that the main composition of bamboo plant ash was SiO2. SiO2 content of bamboo leaf ash (22.89%; 80.28%) was higher than bamboo stem ash (12.36%; 39.17%) and bamboo root ash (11.82%; 61.57%), respectively. The higher Si content in bamboo leaf ash was related to Si deposition in the leaf epidermis.

Characterization and treatment effects on Mutaka kaolin for additive in coatings: Mineral composition, thermal and structural modifications

Previous studies in Uganda have primarily explored kaolin's applications in composites, pottery, bricks, and insulation, neglecting its potential for coatings and paints, which is crucial for industrialization and saving foreign exchange. This study investigates the transformation of kaolin through various treatments and analyzes their impacts on its physical and chemical properties for potential use in coating applications. Thermal analysis, X-ray Fluorescence Spectroscopy (XRF), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), and transmission electron microscopy (TEM) techniques were employed to assess these alterations. The results show that thermal treatment of kaolin at 45.9 °C had minimal impact on mass loss, while the crystallinity of kaolinite was found to be lost around 600 °C, resulting in structural changes. XRF result demonstrates variations in SiO2 and Al2O3 composition, with low TiO2 content desirable for paint and coating applications. XRD results showed well-defined diffractions associated with kaolinite in all treated and untreated kaolin samples. The presence of K-feldspar and quartz are also identified. However, the thermal treatment at 800 °C transforms kaolinite into metakaolin, essential for enhancing coating properties. SEM-EDS results indicate increased porosity and reduced impurities in the thermal-treated sample, which might enhance the whiteness and suitability of pigment and binder dispersion in coatings. TEM images confirmed the hexagonal nature of kaolinite platelets and demonstrated the amorphous nature of kaolin nanoparticles with ammonium molybdate treatment, which led to the delamination and exfoliation of kaolinite layers, improving dispersibility. Kaolin thermally treated exhibited good crystallinity, solid growth, cubic morphology, and uniform size distribution. These findings suggest that tailored treatments can optimize kaolin's properties, making it a promising additive for high-performance coatings.

Impact of Chemical Properties Crumb Rubber with Different Waste Tire in Hot Mix Asphalt Design

The purpose of this research is to assess the impact of chemical properties of rubber crumbs for various types of waste tires mixed in design asphalt. This paper gives a scientific contribution of the chemical properties in relationship with the mix design asphalt. Many tires are replaced and dumped as waste in many parts of the world every year. This has created severe environmental problems such as pollution which governments of many nations spend a lot of budgets to manage every year. However, incorporating rubber crumbs as part of asphalt construction would help solve the environmental pollution problem in the world. The analysis is important because chemical properties such as Zn, Carbon, and Mg, have different characteristics that must be considered in making the best asphalt mix design. This would help to achieve alternate solutions. Furthermore, Utilizing XRD, FTIR, and TGA, the granules of several kinds of waste tire were examined. To achieve the best mix design for the asphalt, the results had many viewpoints. The TGA result demonstrated that all waste tires decomposed at the temperature of 500°C. However, the truck tire waste had the highest maximum thermal decomposition temperature of 587°C. The FTIR result showed that all the tire waste has similar chemical functional groups of polystyrene. The result of XRF showed that truck tire waste possesses the highest Zn content which is considered as dangerous element to the environment.

Modification and Application Study of Activated Natural Zeolite for the Treatment of Liquid Waste from Chemical Laboratory

Natural zeolite from Malang Regency is a raw material that can be used as an adsorbent for heavy metal waste. However, this natural zeolite needs activation and optimization to be utilized maximally as an adsorbent. This study was conducted for both physical and chemical activation of natural zeolite. Characterization results of XRD indicated that the natural zeolite possesses crystalline phases and is of the mordenite type. Based on the XRF results, the Si/Al ratio increased from 5.768 to 6.119 after activation. Based on the characterization results using the BET method with SAA analysis, the surface area of non-activated natural zeolite was determined to be 20.8045 m²/g, while activated natural zeolite had a surface area of 137.8196 m²/g. Results of the adsorption study in treating liquid laboratory waste using simulated Pb and Cr metal wastes demonstrated that activated natural zeolite performed more effectively as an adsorbent than non-activated natural zeolite. The adsorbent’s optimum mass was 0.3 grams, resulting in an adsorption percentage of 97.43% for Pb and 97.56% for Cr, with a contact time of 30 minutes at pH 6. The adsorption kinetics of Pb and Cr metals were described using a pseudo-second-order rate equation. The adsorption of Pb and Cr was depicted using the Langmuir equation, indicating the monolayer formation on the homogenous adsorbent surface during the adsorption process. The activated natural zeolite has the potential to be employed as an independent adsorbent in the treatment of heavy metal waste.

Fe2O3/coal fly ash Fenton-like catalyst for the elimination of organic pollutants in wastewater: Kinetic, mechanism, and application feasibility

Fe2O3/CFA was prepared by loading Fe2O3 on the surface of raw coal fly ash (RCFA), and then used as a Fenton-like catalyst to treat refractory organic wastewater. The characterization results of SEM-EDX, XRD, XPS, XRF, and BET test indicate that Fe2O3 is successfully loaded on the surface of RCFA, while the adsorption performance is not significantly affected. Under optimal treatment conditions of p-nitrophenol (PNP) simulated wastewater (H2O2 dosage = 8 mmol/L, Fe2O3/CFA loading = 6 g/L, pH = 3, and T = 303 K), the removal rate of PNP reaches 97.7 % at 50 min. There exist hydroxyl radicals (·OH), superoxide radicals (∙O2−) and singlet oxygen (1O2) in the Fenton-like system, and ·OH is the primary reactive oxygen species in the removal of PNP·H2O2 dosage, Fe2O3/CFA loading, and pH (i.e., [H+]) show different effects on the generation rate constant of hydroxyl radicals (k·OH), and the corresponding mathematic equation is k∙OH=6.51∙e−640.0T∙[H2O2]1.313∙[Fe2O3/CFA]1.093∙[H+]0.815. The Fenton-like process includes heterogeneous and homogeneous catalytic processes, and it is driven by the synergistic catalysis of multiple metallic elements; Fe and other metallic elements play major and auxiliary roles, respectively. In the advanced treatment of real coking wastewater, the catalytic capacity of Fe2O3/CFA can maintain 91.7 % in its 4th use, and the treatment cost is ¥4.15/ton, which can be decreased by further optimizing the preparation process of Fe2O3/CFA.