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The chemical compositions of refractory materials, such as high-alumina concrete, bricks, and putty, were analyzed using an energy-dispersive X-ray spectrometer (EDXRF). An improved methodology for investigating the effect of particle size on the outcomes of EDXRF chemical analysis is presented. Eight independent refractory samples (refractory concrete, brick, and putty) were pulverized utilizing seven milling times (30, 60, 120, 180, 240, 300, and 360 s) and compared to non-pulverized samples. Thus, sixty-four refractory samples were obtained and analyzed using EDXRF. The method for measuring the fundamental EDXRF characteristics was then tested with ten certified reference materials. The acquired data were compared using inductively coupled plasma atomic emission spectrometry (ICP-OES). Univariate and multivariate statistics are used to evaluate EDXRF data. The particle size of the tested samples affected the z-scores of SiO2, Al2O3, Fe2O3, TiO2, CaO, MgO, Na2O, K2O, and P2O5 concentration measurements. Grinding times for refractory concrete, brick, and putty samples were determined in order to validate the robustness of the EDXRF technique and provide reliable chemical analyses. The ideal milling times for the samples studied ranged from 180 to 360 s, depending on the type of refractory material.

Natural zeolite and bentonite were used as mineral addi-tions to create cement-based building materials that are safe for the environment. This research focuses on the adsorptive qualities of these two clay raw materials, i.e., their propen-sity to immobilize heavy metal ions like Cd2+. The acquired results were examined using kinetic models of pseudo-first and pseudo-second order. The isotherms of Langmuir and Freundlich were examined. Zeolite and bentonite had differ-ent adsorption affinities for Cd2+ cations. Seven cement binders with various mineral additions (fly ash, zeolite, bentonite) underwent a leaching test. The adsorption and hydration mechanisms that immobilized heavy metals within cementitious composites caused leachates obtained on cement samples with the addition of fly ash and clay (either zeolite or bentonite) to contain lower concentrations of Cd2+ ions than leachates obtained on cement samples with fly ash alone.

Due to its chemical composition based on CaCO3 and low price, eggshells, as waste from one of the most widely consumed foods worldwide, are receiving increased attention in building and construction industry studies. The goal of this study was to see if the chemical composition of eggshells could be utilized to distinguish eggs from different production systems. In Serbia, eggs were taken at random from ten commercial cages and ten commercial free-range flocks. Using energy dispersive X-ray fluorescence spectroscopy (EDXRF) and a chemometrics approach, twenty eggshell samples from each flock were tested for element composition (Ca, P, Mg, Na, Al, Cu, Mn, Fe, K, S, and Zn). Analysis showed that free-range eggshells had higher levels of macrominerals (P, Mg, and Na) but lower levels of microminerals (Cu, Fe, K, S, and Mn) than caged eggshells (P<0.05). A large degree of variability within and between production systems was observed for all tested elements. The findings suggest that EDXRF and chemometric analysis of eggshell elemental profiles could provide a useful and effective tool for distinguishing between free-range and caged eggs.

Intenzivna industrijalizacija i urbanizacija dovela je do sve veće potrebe za rešenjima koja će doprineti očuvanju životne sredine. Isto se dešava i u oblasti građevinske industrije, gde se čvrst neorganski otpad sve više koristi kao mineralna sirovina u cementoj industriji. U tom smislu nameću se novi izazovi za prilagođavanje hemijskih metoda za analizu sastava višekomponentnih materijala..., Intensive industrialization and urbanization impose increasing needsfor solutions that will contribute to the preservation of the environment. This is also the case in the construction industry, where deposited solid inorganic waste is increasingly used as a mineral raw material in the cement industry. In this sense, new global tendencies are imposed to improve the performance of chemical analysis methods for the analysis of multi-component materials...

Prirodni zeolit i bentonit korišćeni su kao mineralni aditivi za pripremu građevinskih kompozita na bazi cementa bezbednih za životnu sredinu. Ovo istraživanje se fokusira na adsorpcione kvalitete i mehanizme ove dve glinene sirovine, odnosno njihovu sklonost ka imobilizaciji jona teških metala poput Mn2+. Dobijeni rezultati su ispitani korišćenjem kinetičkih modela pseudo-prvog i pseudo-drugog reda. Ispitane su Langmirove i Frojndlihove izoterme. Zeolit i bentonit imaju različite adsorpcione afinitete za Mn2+ katjone. Sedam cementnih kompozita sa različitim mineralnim dodacima (leteći pepeo, zeolit, bentonit) podvrgnuto je ispitivanju luženja. Mehanizmi adsorpcije i hidratacije koji su imobilisali teške metale unutar cementnih kompozita doveli su do toga da eluati dobijeni na uzorcima cementa sa dodatkom letećeg pepela i gline (zeolit ili bentonit) sadrže niže koncentracije Mn2+ jona od procednih voda dobijenih na uzorcima cementa sa elektrofilterskim pepelom.

In this paper, the main subject concerns comparing different techniques to prepare raw clay samples for energy dispersive X-ray fluorescence spectrometry (EDXRF). Three kinds of sample preparation procedures are examined,such as loose powder, pressed pellet, and fired pressed pellet. The fired pressed pellet approach was observed as a part of universal sample preparation for physic, mechanical, and instrumental analysis, which has not been previously tested as a solution in chemical analysis by the EDXRF method. The observed sample preparation techniques were compared by calculating the parameters of validation (recoveries, limit of detection-LOD, limit of quantification - LOQ, precision, and expanded uncertainties of measurements) of 11 elements (Si, Al, Fe, Ca, Mg, K, Na, Ti, P, Mn, and S) using 15 certified reference materials (CRMs). Calibration curves were created and evaluated using 30 reference materials (RM) for all three approaches. Results proved that the fired pressed pellet is the most practical and precise approach for sample preparation of raw clays.

Pet kompleksnih indeksa (PLI, RI, mERMq, TRI, CSI) određeno je za svaku od 40 lokacija tokom perioda istraživanja (2005, 2007, 2013, 2019) uzimajući u obzir osam teških metala. Primenom klasterske analize (CA) i analize glavnih komponenti (PCA) na vrednosti indeksa zagađenja, izvršeno je prostorno i vremensko poređenje kvaliteta sedimenta. Rezultati statističke analize pokazali su povišen stepen kontaminacije sedimenta u 2005. godini u Kotorskom i Tivatskom zalivu, dok je u 2007., 2013., i 2019. godini bio u Tivatskom zalivu. PCA, CA i indeksi zagađenja ukazali su na povećanje nivoa zagađenja sedimenta u Tivatskom zalivu u periodu od 2005. do 2019.

Eight sediments samples, four from Đavolja varoš and four from Kazár badland have been compared from the perspective of mineralogical composition, petrographic characterization, particle size distribution, pH, electrical conductivity (EC), and the sodium adsorption ratio (SAR).

During the MoDeCo2000 scientific and research project on mortars used in the territory of the Roman Danube Limes in Serbia, the biggest challenge was the quest for the provenance of raw materials. The area where Viminacium, the largest city in the province of Moesia Superior developed, with millennial continuity of land use and settlement, was selected as research case study and is presented in this research. People throughout history have always used what they had at hand, and the building remains were not only reused but also recycled for new constructions. Thus, the building material of Roman Viminacium has survived in the landscape through the in situ preserved remains of Roman buildings, as well as in the structures from the later periods, up to today. To the best of our knowledge, the use of natural sediments baked during the self-combustion or combustion of underneath layers (coal in our case) for the purpose of construction was extremely rare in the Roman Empire. In this study, we follow the presence of this type of material precisely in Viminacium construction, naming it natural brick, while focusing on its potential use in lime mortars whose production was perfected in the Roman period and has never been surpassed afterward. Archaeological contexts in which this material was found have been studied, along with simultaneous work in the laboratory and in the field during the research and experimental use of the natural brick in lime mortars. We sought to determine whether this material could have been recognised by Romans in Viminacium as a potential valuable pozzolanic component of mortar, along with or instead of fired brick, being locally available and recyclable. The final confirmation of its pozzolanic features and later discussion open completely new directions for the future research of Viminacium lime mortars.

A diversity of factors, led by lithology, weathering, and erosion processes, plays a significant role in the formation and future of badland terrains. Then on previous observations it can be concluded that surface flow processes are the first trigger of erosion and that intense soil erosion combined with rapid and deep weathering are tightly connected to high erosion rates. Since climate change presents a global issue that gains increasing attention and due to the complexity of the interactions and processes that are a part of general badlands origin and evolution, a weathering experiment on badland sediments from China was conducted. Explaining temporal changes, the impact of different precipitation types and its durations of exposure on sediments during weathering processes, as well as its impact on leachate ions behaviour are the aims behind this experiment. Red clayey siltstone and mudstone badland sediments selected for the laboratory experiment were organized in four sets that included three different samples, making a total of 12 treated samples. Based on field climate data, in laboratory conditions samples were exposed to rain, acid rain, snow, and acid snow through fifteen daily cycles. Leachate was collected after each cycle and its volume, pH, electrical conductivity (EC), and ion concentrations were measured and analysed from the leachate. Changes occurring on the surface of the sample were observed through photographs taken at the end of each cycle. Based on obtained results it can be said that the main differences occur when comparing rain and snow treatments generally. Temporal, cyclic changes were, to a certain extent, noticed through sediment decay. More importantly, durations of sediment exposure to precipitation proved to be crucial for weathering processes of tested siltstones and mudstones, having exclusion and ionic forces - ion exchange chromatography as dominant chemical processes.

Many studies on techniques for diminishing the environmental impact, reducing greenhouse gas emissions, and decreasing industrial and biowaste have been conducted with the mutual goal of achieving sustainable development. The use of industrial byproducts as raw materials for cement clinker production is becoming more common in the Portland cement industry. Eggshell is a biowaste produced in huge quantities by households and the food industry. Eggshell powder has a trigonal-calcite structure and properties similar to limestone; therefore, it can substitute limestone in the cement clinker mix design. In this work, bio-waste cement was produced at temperatures below the standard 1470°C utilizing mechanically activated eggshell powder. Under the same conditions as bio-waste cement, limestone cement clinker was also synthesized. Instrumental tests (X-ray diffraction, scanning electron microscopy, differential scanning calorimetry, and thermogravimetry analysis) were employed to analyze the mineral phases in the produced cements. The results showed that eggshell-cement had four major cement clinker phases (C3S, C2S, C3A, and C4AF) that were identical to those in ordinary commercial Portland cement. As a result, this study demonstrated that it is possible to recycle eggshell waste to partially substitute limestone as a raw material for cement clinker manufacturing.

A modification of an analytical procedure for the energy-dispersive X-ray fluorescence (EDXRF) quantification of ten chemical elements (As, Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb and Zn) in the leachates obtained from cement binders was developed. Twenty-nine testing samples were used in the experiment. All samples were based on Portland cement. Fly ash of different origin, zeolite and bentonite were employed as mineral additives in the cement binders. Distilled water was used as the leachate. Validation of the modified EDXRF procedure was conducted in terms of limits of detection and quantification, working range, linearity, selectivity, precision, trueness, and robustness. Traceability of the procedure was established using certified reference materials. Uncertainty of measurement was confirmed via an "in-house" laboratory validation approach. The expanded uncertainties for the ten analysed elements were obtained for the entire working range of the EDXRF method. Robustness of the modified EDXRF procedure was assessed by means of a chemometric in-house approach. The results obtained by the modified X-ray fluorescence method were additionally correlated to those acquired by inductively coupled plasma optical emission spectrometry to confirm that EDXRF could be used as an effective and reliable alternative method for analysis of cement leachates.

Prirodni zeolit i bentonit korišćeni su kao mineralni dodaci u mešavinskom dizajnu ekološki sigurnih građevinskih materijala na bazi cementa. Ispitane su adsorptivne sposobnosti ove dve glinene sirovine, tj. njihov afinitet da imobiliziraju jone teških metala Zn2+, Ni2+, Pb2+ i Cu2+. Za eksperiment su pripremljeni pojedinačni i multi-rastvori Zn2+, Ni2+, Pb2+ i Cu2+ . Dobijeni rezultati su analizirani pomoću kinetičkih modela pseudo prvog i pseudo drugog reda. Analizirane su izoterme Langmuira i Freundlicha. Bentonit je pokazao bolji adsorpcioni afinitet od zeolita prema sva četiri ispitivana katjona. Kao dokaz, ispitano je ispitivanje ispiranja na sedam različitih veziva za cement sa različitim mineralnim dodacima (leteći pepeo, zeolit, bentonit). Eluati dobijeni na uzorcima cementa sa dodatkom letećeg pepela i gline (bilo zeolita ili bentonita) sadržavale su niže koncentracije jona Zn2+, Ni2+, Pb2+ i Cu2+ u odnosu na eluat dobijen na uzorcima cementnog veziva sa letećim pepelom. Razlog za dobijanje ovakvih rezultata su adsorpcioni i hidratacioni mehanizmi koji imobiliziraju teške metale u cementnim kompozitima., Natural zeolite and bentonite were utilized as mineral additives in the mix-design of environmentally safe cement-based building materials. The adsorptive abilities of these two clayey raw materials, i.e. their affinity to immobilize heavy metal ions Zn2+, Ni2+, Pb2+ and Cu2+ were investigated. Singleand multi-solutions of Zn2+, Ni2+, Pb2+ and Cu2+ were prepared for the experiment. The obtained results were submitted to analysis via pseudo-first and pseudo-second order kinetic models. Langmuir and Freundlich isotherms were analyzed. Bentonite exhibited better adsorption affinity than zeolite towards all four investigated cations. As a proof, a leaching test was conducted on seven different cement binders with different mineral additives (fly ash, zeolite, bentonite). The leachates obtained on the samples of cement with addition of fly ash and clay (either zeolite or bentonite) contained lower concentrations of Zn2+, Ni2+, Pb2+ and Cu2+ ions than leachates obtained on the samples of cement binder with fly ash solely as a result of adsorption and hydration mechanisms that immobilized heavy metals within cementitious composites.

The surface sediments sampled from forty sampling sites in the Boka Kotorska Bay, starting from October 2005 to December 2019, were analysed for the content of ten heavy metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Fe). Five complex indices (pollution load index (PLI), potential ecological risk index (RI), mean ERM quotient (MERMQ), toxic risk index (TRI), contamination severity index (CSI)) were determined for each site in the study period (2005, 2007, 2013, 2019), and statistically examined by principal component analysis (PCA) and cluster analysis (CA). In the semi-enclosed Bay, which consists of four smaller bays (Kotor, Risan, Tivat, Herceg Novi bays), a spatio-temporal comparison of sediment quality was carried out using PCA and CA analysis of the considered pollution indices. Statistical results revealed that the increased environmental risk in 2005 was observed in the bay of Kotor; in 2007 was in the bay of Tivat and Risan; in 2013 in the bay of Kotor and Tivat; and in 2019 was in the bay of Tivat, particularly at the shipyard site Bijela. The PCA and CA analysis highlighted that the sediment contamination in Kotor bay decreased from 2005 to 2019, while at the same time increased in Tivat bay, which is an indication of pollution due to urbanization and population growth in this part of the Bay. The results gave a statistical overview of the similarities between the pollution indices and the differences in the degree of sediment pollution in the Bay during the last two decades.

The sediment was collected at forty locations in the Boka Kotorska Bay, in different seasons and years (October 2005, June 2007, April 2013, December 2019), and analyzed using the EDXRF method. The aim of this work was to evaluate the potential risk and compare heavy metal pollution (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Zn, Fe) of surface sediments in the period 2005-2019. Environmental risk assessment was performed by comparative analysis of pollution indices, such as pollution load index (PLI), potential ecological risk index (RI), mean ERM quotient (MERMQ), toxic risk index (TRI), and contamination severity index (CSI). The average contribution of individual metals in the total environmental risk showed the following order: Cd > Hg > As > Pb > Ni > Cu > Cr > Zn. Accordingly, Cd represented a concern of the highest priority for the Bay ecosystem due to its high toxicity. The results indicated that Hg concentrations showed a declining trend in the period from 2005 to 2019. Referring to the results of all applied pollution indices, it was established that the highest pollution was identified in 2019, particularly at the shipyard site S4, while the lowest pollution was recorded in 2005 and 2013. The spatial distribution of pollution indices for each investigated year revealed the most polluted sediments at sites S4 and S10 in Tivat bay. These findings provide insight into the comparison of different indices in assessing the sediment quality in the Boka Kotorska Bay over the last two decades.

The mortars have been always one of the most interesting topics for the researchers of Roman building constructions. The knowledge on this complex building material used in Roman architecture is mostly based on the research of the monumental structures in the territory of today Italy. However, many mortar examinations were executed by the researchers of provincial Roman archaeology as well, who tried to find evidence of the quality of building activities in the provinces. The territory of today's Serbia, except for the existence of scarce studies, was never in the research focus. Even the monumental bridge over the Danube, built at the beginning of the 2nd century that made Trajan’s conquest of Dacia possible, was not researched thoroughly enough when we speak of its building materials. During the last few years, the interest in the Roman buildings at the Danube territory has grown. Mortar Design for Conservation – Danube Roman Frontier 2000 Years after (MoDeCo2000) project is funded by the Science Fund of the Republic of Serbia. Its aim is to investigate the mortars used in Roman buildings along the former Danube Limes in Serbia, as well as to offer mortar recipes for building conservation practice.

Roman mortars have long been one of the most intriguing topics in the field of construction history, which together with archaeology has embraced many sciences and professional practices in order to unravel the technologies and knowledge of ancient builders. Among them, geology occupies a special place in the investigation of the origin of raw materials. At the same time, with the help of chemistry, it looks for their mutual relationships, which eventually led to composites with the use of which the most monumental Roman buildings were erected.

This study presents the 51 mixtures of ceramic clays characterized by using XRF, XRD, granulometry, and dilatometry analyses. After firing in a 1000-1250 °C range, water absorption (WA) according to EN standards by boiling in water, under vacuum, and by 24 h soaking is determined. The results indicated that there was a high and statistically significant correlation between the standard methods, but the testing under vacuum gave the highest saturation of the samples fired at 1200 °C and 1250 °C. It is determined that these illitic-kaolinitic clays can be used to produce floor ceramic tiles belonging to the BIIa group (water absorption between 3% and 6%). The study also aimed to reveal which method of WA determination is suitable to read the sintering interval from the gresification diagrams, which is compared to the beginning of sintering as read from dilatometry curves.

One of the significant problems in the production of ceramic tiles is the very high consump-tion of natural resources such as clay, feldspar, and quartz. The possibility of replacing part of the formulation of ceramic batches is of great importance. In this research, the possibility of using aplitic granite waste from dimensional stone production was analyzed in detail. The waste is considered a low-cost substitute for feldspar in Serbia. The milled powdery waste was analytically tested to reveal its chemical and mineralogical contents, particle size distribution, and other important properties. The ceramic tiles containing aplitic granite waste (GW) and GW/raw clay mixture (CGW) were hydraulically pressed, and the ceramic and technological properties determined. This waste can act as a filler while forming, drying, and firing, since the high content of quartz helps to control the shrinkage and acts as a fluxing agent in high temperatures due to its feldspathic nature. The waste was found favorable in the production of ceramic tiles, as the gained values of modulus of rupture and water absorption were 28.68 MPa and 1.33%, respectively. The parameters defined in the series of standards EN ISO 10545 were tested on a semi-industrial probe, determining that this combination of materials (without the addition of quartz) may be efficiently used to produce ceramic floor tiles. The usage of what would otherwise be waste material contributes to sustainable management and environmentally friendly solutions by avoiding landfilling, while at the same time it enabling the conservation of scarce natural feldspar deposits.

Adjustment and subsequent validation of energy-dispersive X-ray fluorescence (ED-XRF) method for cement based binders with addition of mineral raw materials (fly ash, zeolite and bentonite) was conducted. Eighteen chemical elements present in the material composition were analyzed: ten major elements (Si, Al, Fe, Ca, Mg, S, Na, K, Ti, P) and eight trace elements (Cr, Zn, Cu, As, Ni, Pb, Sr, Mn). Thirty-five samples of either certified reference materials or reference materials of cement, fly ash and clay were utilized during adjustment and optimization of the investigated ED-XRF procedure. The method was consecutively validated in terms of selectivity, precision, working range, linearity, accuracy, robustness, limits of detection and quantification. Thirty-two samples in total, i.e. three certified reference materials and twenty-nine reference materials, were simultaneously analyzed by ED-XRF and inductively coupled plasma optical emission spectrometry (ICP-OES). Comparison of the outputs of monitored methods showed infinitesimally small differences, as correlation coefficients were extremely good (approximate to 1), which highlighted ED-XRF as highly satiable alternative for ICP-OES for the chemical analysis of cement binders.

New global tendencies for waste materials reusing in building materials are imposing the request for improved performances of chemical analysis methods and the improvements of matrices used. A new method for optical emission spectrometry with inductively coupled plasma (ICP-OES) is developed and validated for the chemical analysis (35 elements: Al, Be, Cd, So, Cr, Cu, Fe, Mn, Mo, Ni, V, Mo, Zn, Pb , Bi, Si, Zr, W, As, Se, Sb, Sn, Ti, Ba, B, Ag, Mg, Ca, K, Na, S, P, Ga, In, Li) in leachate of fly ash. Validation performances and the uncertainty of measurement were resolved. Uncertainty of measurements were resolved by three routes: validation procedure, participation in proficiency testing (PT) schemes and standard method. The obtained method is a new simple and effective analyzing route for determination of undesired trace elements and their quantity comprised in leachates of fly ash, and leachates of building materials with addition of fly ash (cement binders and mortars). In order to prove its accuracy and precision, the developed method was employed on laboratory samples of cement binders and mortars. Results were compared with limit values provided in the standard. Multivariate analyses, i.e. cluster analysis and principal component analysis, were applied to establish interrelations between analyzed samples, and to certify the developed ICP-OES method.