In the context of industrialisation and globalisation, there is an alteration of the chemical composition of surface waters. These changes have consequences for the entire ecosystem, including the atmosphere, hydrosphere, biosphere, and pedosphere. Consequently, monitoring and prevention are mandatory processes used to study and quantify ongoing chemical processes. The aim of this study was to provide a comprehensive evaluation of sediment and water contamination in the designated area, with a particular emphasis on potentially toxic elements (PTEs). Consequently, a total of 120 water samples and 120 sediment samples were collected during 2024, encompassing all four seasons: spring, summer, autumn, and winter. A variety of methodologies were employed to investigate the contamination of water and sediments. A series of analytical procedures were applied to determine the chemical composition of water samples. These procedures included electrochemical sensing methods for pH, electrical conductivity, oxidation–reduction potential, dissolved oxygen, and total dissolved solids. Additionally, a turbidimetric method was employed to measure turbidity. UV–Vis spectrophotometry was utilized to ascertain the total hardness, total carbon, inorganic and organic carbon, organic fatty acid, total nitrogen (Ntot), nitrate, starch, chloride, fluoride, sulfide, sulfate, sulfite, organic acids, phosphate, phenol, silica, As, Al, Ag, B, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Rb, Se, Sn, Sr, Zn, and Zr. The estimation of pollution was conducted by employing the nitrate pollution index, the ammonium pollution index, and the metal pollution index. The hazard quotient, hazard index, and carcinogenic risk methods were applied for health risk assessment through water ingestion and dermal contact. The analysis of metal content in sediments was conducted using a mass spectrometry method, determining elements such as Pb, Cr, Co, Cu, Ni, Zn, Mn, Fe, Ca, K, Mg, and Na. The transfer of metals from sediment to water was determined using the transfer factor method. Meanwhile, the ecological risk assessment was conducted using the potential enrichment factor and probability of toxicity. The results of the water pollution assessment indicated significant levels of heavy metal contamination (scores ranging from 20 to 57, with an average score of 37.4) and moderate NO₃⁻ pollution (scores ranging between 0.836 and 0.863). Sediment analysis indicated minimal enrichment with PTEs (scores < 2.0), and low probability of toxicity (scores: 0.021–0.053). A risk assessment was conducted on Fe, and it was determined that ingestion of Fe by children posed a concern. However, dermal contact with Fe was determined to pose no threats. It was determined that the contamination levels generally pose low to moderate risks for adults. However, children are more susceptible to health effects, especially from exposure to Fe. Consequently, this study emphasizes the necessity of implementing a comprehensive monitoring program for priority pollutants, the development of treatment methodologies for contaminated water sources, the promotion of community awareness initiatives concerning safe water usage, and the implementation of targeted remediation strategies in high-risk areas. These measures are crucial to ensure the long-term safety and sustainability of local water resources.

This study assesses the physicochemical quality, metal contamination, bioaccumulation patterns, and potential human health risks related with two lake water systems (samples CI and FI). Water quality assessment, according to the Water Quality Index (WQI) exposed excellent overall status in both lakes, with variations driven by chemical composition. The CI sample exhibited a slightly higher WQI due to elevated concentrations of heavy metals and nitrogen compounds and a lower pH, while FI sample showed the lowest WQI score, reflecting minimal chemical contamination. Heavy metal pollution indices confirmed low contamination levels in both lakes, despite CI presenting moderately higher cumulative metal concentrations. Nitrogen-based indices indicated negligible NO3- influence and no ammonium-related pollution, further supporting the overall good water quality. Metal bioaccumulation patterns were strongly species- and tissue-dependent, with Fe being the most environmentally significant element at both sites. Fe dominated bioaccumulation in fish from both FI and CI sites, showing the highest bioconcentration factors, particularly in liver tissues. Mn and Zn accumulated substantially, mainly in intestines, gills, and bones. Li, Sr, Ca, and Ba exhibited consistently low bioaccumulation across species and tissues. The liver acted as the primary metal sink, while muscles and skin showed minimal accumulation. Human health risk evaluation demonstrated no non-carcinogenic or carcinogenic risks from water ingestion or dermal exposure, with scores remaining within safe limits for adults and children. Similarly, metal content in fish were within acceptable levels, and indices scores remained lower than 1.0, presenting no significant health risk after fish ingesting. Overall, the findings confirm that both FI and CI lake systems maintain high water quality, low heavy metal contamination, and negligible health risks, despite moderate differences in chemical and bioaccumulation profiles.

The influence of Zn2+, Ca2+ and Co2+ doping on the thermal, structural, morphological, and magnetic characteristics of CdBi0.1Fe1.9O4 nanoparticles synthetized via the sol–gel technique and calcined at 300, 600, 900 and 1200 °C was investigated. Thermal analysis revealed the initial formation of metallic glyoxylates up to 300 °C, followed by their decomposition into metal oxides and subsequent ferrite formation. X-ray diffraction revealed that the ferrites were poorly crystallized at lower temperatures, whereas at higher calcination temperatures all nanocomposites exhibited well-crystalized ferrites coexisting with the SiO2 matrix, except for the Co0.1Cd0.9Bi0.1Fe1.9O4@SiO2 nanocomposite, which formed a single, well-defined crystalline phase. Atomic force microscopy images revealed spherical ferrite particles encapsulated within an amorphous layer, with particle size, surface area, and coating thickness influenced by both the type of dopant ion and the calcination temperature. The structural parameters estimated by X-ray diffraction, as well as the magnetic characteristics, were strongly influenced by the dopant type and thermal treatment. These results demonstrate that the structural and magnetic characteristics of CdBi0.1Fe1.9O4 ferrites can be effectively tuned through controlled doping and calcination, providing insights for the design of tailored functional applications.

The present study introduces a monitoring initiative focused on the quality of surface water quality of the water samples collected from Iza and Tisa rivers, situated in the Sighetu Marmatiei locality in the Upper Tisa, a Natura 2000 protected area, in the North-West region of Romania. The study assessed the evolution of 15 chemical indicators (electric conductivity, pH, oxide-reduction potential, dissolved oxygen, total hardness, turbidity, fluoride, chloride, ammonium concentration (NH4+), nitrates (NO3-), nitrites (NO2-), sulphate (SO42-), Total Dissolved Solids, alkalinity (HCO3-, CO32-)), and 20 metals (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Sr, Zn) in the water samples, and 12 metals in sediments collected from Isa river (As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sb, Zn), which were monthly measurement in the year of 2024. The objectives of this study were: (1) to assess the quality of Iza and Tisa rivers by measuring and analyzing the chemical load. (2) To identify the extent of the anthropogenic pressures and to elaborate measurements destined for mitigation of negative anthropogenic emission and environmental alterations. (3) To determine the typology of Iza river by applying the Total Ionic Salinity chart based on the major ions, Gibbs Piper and Ficklin-Caboi plots, indicating the precipitation, rock dominance, and silicate weathering, characterizing all studied surface waters. (4) To identify and evaluate the metal pollution in water and sediments, based on metal pollution index (MPI), and the human health risk at metals through variate risk indices (HQ and CDI). (5) To calculate the transfer of metals from Isa River to sediments, and to determine the ecological impact based on the enrichment factor and geoaccumulation index. Piper diagram indicated Ca-Na-HCO3- mixed typology, attributed to mineral solubilization or recharge water, and the Ficklin-Caboi chart indicated near-neutral high metal type of waters. According to the metal pollution indices scores, most surface waters (86 %) were characterized by medium pollution with the metals of interest. The mean scores varied between the critical range of 30-15, indicating medium pollution, MPI scores ranged between14.9-22.8 respectively. No human health risk at metals through ingestion for adults and children was determined, based on the hazard quotient scores which were lower than the critical value of one. Generally, the descendent trend associated to the transfer of metals from sediment to water was: Fe>Mn>As>Cu>Pb>Co>Cr>Sb>Ba>Ni>Cd>Zn. Generally, samples had a depletion to minimal enrichment with heavy metals (ER <2.0), especially with Cr, Fe, Ni, and Pb. All samples present significant enrichment (5.00

The present study aims to perform a comparative analysis of the chemical composition and thermal behavior of two distinct milk types, namely animal and plant-based. The thermal analysis revealed the presence of the following classes of compounds: hydrocarbons, heterocycles, aldehydes, ketones, amines and alcohols. All types of milk contain saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs), though the relative proportions of these vary depending on the specific milk type. Animal milk powders contain SFAs, including palmitic, stearic, and myristic acids, as well as moderate amounts of MUFAs, such as oleic and palmitoleic acids. They also contain lower PUFAs, including linoleic and alpha-linolenic acids. In contrast, plant-based milk powders, particularly soy milk powder, are rich in both linoleic and alpha-linolenic acids. Plant-based milk typically exhibits lower levels of SFAs and higher levels of MUFAs and PUFAs when compared to milk of animal origin. In conclusion, the fatty acid profiles of animal and plant-based milk powders reflect the different nutritional attributes and health implications associated with each. Thermal behavior analysis offers insights into the stability and potential flavor changes that may occur during processing and storage. The comparative analysis highlights significant differences in the chemical composition and thermal behavior of animal and plant-based milk powders.

Introduction The storage stability and quality of seabuckthorn, aronia and black currant juices, unsweetened and with added honey, was analyzed in terms of sensory, physico-chemical, microbiological, thermal and antioxidant properties.Methods 6 juices assortments were obtained and analyzed using fresh seabuckthorn with honey and without honey, aronia with honey and without honey, black currant with honey and a juice prepared of 50% seabuckthorn and 50% aronia without honey. The thermal analysis of juices which evaluated the thermal behavior of juice assortments in air up to 600 degrees C. The physico-chemical were analyzed: total sugar content, acidity, dry matter content, electrical conductivity, ascorbic acid content, polyphenol content, pH and antioxidant capacity. Sensory attributes of juices such as appearance, color, smell, taste, foreign bodies were analysed. The microbiological analysis monitored the degree of preservability over time, evaluating the samples immediately after unpacking and subsequently at 7-day intervals up to 56 days of refrigeration.Results and Discussion The thermal analysis of juices has been less studied; however, it is highly interesting due to the specifics provided on juice composition and practical uses, particularly the potential to produce dry powder forms of juices. Thermal behavior of juices was assessed. Based on thermal analysis, details on the juice composition were obtained such as dry matter, water content, honey content of juices. The juices showed low pH values (2.78 - 3.75), higher sugar content in the case of honey sweetened juices (38.4 - 42.9 Brix) compared to juices without honey (9.5 - 18.3 Brix), high ascorbic acid content (62.4 - 94.19 mg/100 g), high concentrations of polyphenols (2211.47 - 4614.17 mg EAG/L) and high antioxidant capacity as scavenging capacity of 2,2-diphenyl-1- picrylhydrazyl (DPPH) (87.05 - 94.19 %). The microbiological analysis monitored the degree of preservability over time, evaluating the samples immediately after unpacking and subsequently at 7-day intervals up to 56 days of refrigeration. The microbiological quality of the juices remained within acceptable limits up to the 14th day of refrigeration, after which a significant increase in yeasts and molds was observed, exceeding 5 log CFU/mL. The prepared juices were high in compounds with health benefits such as vitamin C, polyphenols, that showed a high antioxidant capacity and can be consumed up to 14 days of storage in refrigerated conditions.

This study was carried out to fill the present research gap in the study area by assessing water chemistry, potential heavy metal contamination, and the associated health risk evaluation that goes along with it in surface water bodies and groundwater in the NE of Maramureș County, near the Tisa River. The main methods we applied were Piper, Ficklin–Caboi, and Gibbs diagrams for determining the water typology and chemistry, the Overall Water Quality Index (OWQI) and vegetation cover to determine the water quality, a contamination index for analyzing the contamination degree, and a human health risk assessment through water ingestion after exposure of children and adults. This article’s main findings specify that waters were characterized and classified into the CaMgHCO3− dominant category of water type, with precipitation, agricultural, and domestic inputs, related to the Cl− (mean ranging between 1.01–5.65 mg/L) and NO3− (mean ranging between 2.23–5.52 mg/L) content. The OWQI scores indicated excellent quality, below the critical value, ranging between 0.70 and 6.57. The applied risk assessment indicated that the daily intake of toxins is higher in the case of children than in adults, up to four and five times. The hazard quotient scores, ranging between 0.00093 and 0.248 for adults and between 0.0039 and 1.040 for children, indicated that if consumed, the studied waters can pose potential negative effects on children.

The influence of Cd2+ content and heat treatment on the morphology, structure and magnetic behavior of CdxZn1-xFe2O4 (x = 0.0; 0.2; 0.4; 0.6; 0.8; 1.0) nanoparticles encapsulated in SiO2 produced by the sol-gel route was studied. At 800 degrees C, Fe2SiO4, Fe2O3 and CdO accompanied the poorly crystallized ferrites, while at 1200 degrees C the well crystallized ferrite was convoyed by Zn2SiO4 and SiO2. Encapsulation of nano-sized CdxZn1-xFe2O4 in inert SiO2 allowed the particle size control, minimized agglomeration, and improved the magnetic behavior. The low heat treatment temperature produced well-individualized nanoparticles of similar to 40 nm, with the particle diameter being larger than the ferrite crystallites due to the SiO2 coating. Increasing the Cd2+ content resulted in small particle size, whereas increasing the heat treatment temperature led to larger particle size, resulting in submicron clusters. The increase of Cd2+ content and heat treatment temperature also determined the increase in lattice constant, density and hopping length and the decrease in crystallite size and porosity. The nanoparticles were found to be mesoporous with a narrow pore size distribution. The magnetic features increased with heat treatment temperature and decreased with increasing Cd2+ content until paramagnetic-like behavior was reached for CdFe2O4.

The (Ni0.5Cd0.5Fe2O4)x(SiO2)100-x (x = 0%-100%) samples were synthesized through sol-gel technique followed by the study of the evolution of crystalline phases at different temperatures. For the samples containing ferrite, the X-ray diffraction indicated the development of ferrite and SiO2 matrix and displayed single, low crystallized ferrite at low temperatures and well-crystallized ferrite attended by Fe2O3 and SiO2 at high temperatures (1000 degrees C). The crystallite size and lattice parameter increased with annealing temperature and the amount of ferrite incorporated in the SiO2 matrix. The evolution of shape, size, and degree of agglomeration with the amount of ferrite incorporated in the SiO2 matrix at 1000 degrees C were investigated. The values of remanent and saturation magnetizations, anisotropy and coercivity, and the amount of ferrite incorporated in the SiO2 matrix after annealing at 700 degrees C and 1000 degrees C were correlated with the particle morphology. The SiO2 matrix exhibited diamagnetic behavior, while the Ni0.5Cd0.5Fe2O4 incorporated in the SiO2 matrix showed a superparamagnetic behavior. The amount of ferrite and annealing temperature impacts the particle sizes, which further affects the magnetic characteristics. The incorporation of Ni0.5Cd0.5Fe2O4 nanoparticles into the inert SiO2 matrix enabled the control of particle size, minimized particle agglomeration, and enhanced the magnetic properties.

The main aim of the current work was to study the composition of volatile compounds (VOCs), fatty acids (FAs), antioxidants, and polyphenols and the thermal behavior and, as well as the piperine content in white, green, black, red, and pink peppers. The thermal analysis demonstrated several conversions in the pepper composition, specifically water loss, drying, and decomposition of VOCs, FAs, cellulose, amino acids, lignin, and hemicellulose. Monoterpene hydrocarbons dominated in all pepper, having the highest values in the case of pink pepper, while the lowest quantity of monoterpenes was observed in black pepper. The VOCs in peppers were classified into four odor classes (citrus (56.2

The current work reports the characterization of bismuth-doped cobalt ferrites with the general formula CoBi phi Fe2-phi O4 (phi = 0.2-1.0) incorporated in SiO2, prepared by the sol-gel method and heat-treated in air at different temperatures (400-1300 degrees C). The correlation between the trivalent ion content, heat treatment temperature, morphology, structure, thermal and magnetic properties was evaluated. Thermal analysis confirmed the formation of Co, Bi and Fe succinates at 141-210 degrees C and their decomposition to ferrites at 287-318 degrees C. The development and decomposition of succinate precursors, followed by the formation of spinel ferrite and SiO2 was confirmed by infrared spectroscopy. The formation of Co-Bi ferrites with crystallite sizes of 41.2-107.5 nm was studied by X-ray diffraction. Crystalline ferrites were accompanied by the SiO2 crystalline phases at high heat treatment temperatures, while poorly crystalline ferrite was attended by silicates at low heat treatment temperatures. Atomic force microscopy images revealed rounded nanoparticles composed of a ferrite core covered by a thin SiO2 layer at low heat treatment temperature and rounded cube-shaped ferrite cores covered by a thin SiO2 layer at high heat treatment temperatures. The heat treatment temperature and the Bi3+ doping increase caused the increase of the particle size and the change of the ferrite core shape. The nanocomposite phi = 0.2 had the highest coercivity, saturation and remanent magnetizations, and the magnetic properties decreased with increasing Bi3+ doping.

In the context of fast industrialization and urbanization, which led to an increase in the flux of certain toxic chemicals into rivers and sediments, this study employed a variety of perspectives to determine and assess levels of heavy metal and nitrogen compound pollution. The applied data analysis revealed that the Viseu river, Romania is abundant in NH4+ and Mn, with concentrations that surpass the maximum permissible concentrations stipulated by both national and international regulatory frameworks. In this context, pollution indices were used to assess the potential pollution degree of the river. The nitrate pollution index scores varied between 0.926 and 0.960, and the ammonium pollution index scores ranged between -0.96 and 2.64, indicating pollution of waters with nitrate and ammonium (attributable to intensive agricultural activities within the study area). Given the prevalence of industrial activities, it is notable that more than 50 % of the studied waters exhibited levels of pollution with Cu, Mn, Ni, and Zn. These findings are supported by heavy metal pollution indices scores ranging from 145 to 1578. The heavy metal content was analysed in sediments collected from Viseu river. The trend of metals varied as Al>Mn>Zn>Cu>Pb. Pollution indices indicated that 75 % of sediments are very high contaminated with Cd, and 50 % with Mn. Ecological risk index indicated that VV8 presents very high ecological risk, 50 % of samples considerable risk, and 25 % moderate ecological risk. Given the potential water contamination, a risk assessment was conducted. This entailed the evaluation of non-carcinogenic risk, conducted in two distinct scenarios (adults and children) through two exposure pathways (dermal contact and ingestion of NO3- and heavy metals subsequent to water ingestion). The findings showed that dermal exposure to Cu, Mn, Ni, and Zn posed a non-cancer risk in children (values 0.175-786) and to Mn and Cu in adults (0.6-13). With regard to the potential non-cancer risk from water consumption, adults are considered safe, but children present vulnerability (0.0006-2.53). Mitigation and risk control strategies for toxic chemicals are imperative to be developed and applied in the study area, to prevent potential hazards.

This study compares the structural, morphological, magnetic, and photocatalytic properties of a pure SiO2 matrix, a ZnFe2O4-doped SiO2 nanocomposite (both synthesized via the sol-gel method), and bulk ZnFe2O4 produced by thermal decomposition. Thermogravimetric analysis (TGA) reveals that metal oxalates form below 200 °C and decompose into metal oxides, which subsequently form ferrite. Fourier-transform infrared (FTIR) spectroscopy confirms the embedding of both undoped and ZnFe2O4-doped nanoparticles into the SiO2 matrix at all investigated annealing temperatures. X-ray diffraction (XRD) consistently reveals the formation of crystalline ZnFe2O4, with the crystallite size increasing from 48 to 93 nm upon annealing. Atomic force microscopy (AFM) shows spherical ferrite nanoparticles surrounded by an amorphous layer, with particle growth observed at higher temperatures. Structural parameters derived from XRD (e.g., crystallite size, density, porosity, lattice constant, unit cell volume) and AFM (e.g., particle size, coating thickness) as well as magnetic parameters (saturation magnetization, remanence, anisotropy, coercivity) demonstrate clear dependence on both dopant presence and annealing temperature. Magnetic measurements reveal enhanced properties with increasing ferrite content and heat treatment, with a transition from superparamagnetic behavior at 700 °C to ferrimagnetic behavior above 1000 °C. Scavenger experiments confirmed the involvement of holes, hydroxyl radicals, and superoxide radicals in the photocatalytic process. The photocatalytic efficiency, as evaluated by the Rhodamine B degradation under visible light, highlights the promising potential of the obtained nanocomposite for advanced environmental and technological applications.

The present work shows the characterization of NixZn1-xBi0.3Fe1.7O4 (x = 0–0.5) incorporated into a SiO2 matrix, obtained by using a sol-gel method. The thermal analyses confirmed the development of Ni, Zn, Bi and Fe succinates at 131–190 °C and their transformation thorough decomposition into metal oxides at 260–314 °C, that subsequently undergo reactions to produce ferrites. The formation, development and decomposition of glyoxylate precursors, followed by their incorporation in the SiO2 matrix and the formation of spinel ferrite were confirmed by infrared spectroscopy. The formation of Ni-Zn-Bi ferrites with crystallite sizes in the range of 49.1–98.6 nm was established by X-ray diffraction. At high heat treatment temperatures, crystalline ferrites were integrated into the crystalline phases of the SiO2 matrix. At low heat treatment temperatures, poorly crystalline ferrites accompanied by silicates were formed. All the analyzed samples exhibit a certain degree of porosity. Mesoporous are present within a narrow pore size distribution. The photocatalytic performances of the samples investigated were evaluated by studying the degradation of Rhodamine B under the action of visible light. High amounts of Ni in the sample lead to the best removal performance, 77

The influence of various proportions of Co0.5Zn0.5Bi0.2Fe1.8O4 (x = 25–100 %) dispersed in a SiO2 matrix, as well as the effect of calcination temperature on the morpho-structural and magnetic characteristics of (Co0.5Zn0.5Bi0.2Fe1.8O4)x(SiO2)100-x nanocomposites (NCs) was explored using X-ray diffraction (XRD), atomic force microscopy (AFM) and vibrating sample magnetometry (VSM). At all calcination temperatures, the NC with x = 100 % showed the well crystallized ferrite phase, while the NCs with x = 25–75 % displayed well crystallized ferrite phase accompagnied by cristobalite and quartz. The particle size increased progressively from about 30 nm at low calcination temperatures (300, 600 and 900 °C) to about 100 nm at 1200 °C, along with the ferrite content in the composition. The correlation between ferrite crystallite and nanoparticle size revealed that the SiO2 outer glaze is rather a constant layer of about 2–4 nm. The remanent magnetization, saturation magnetization, coercivity and anisotropy constant increased with the ferrite content dispersed in the SiO2 matrix. In this regard, dispersing mixed Co-Zn-Bi ferrite nanoparticles into the SiO2 matrix minimized the particle agglomeration, and allowed a fine tuning of particle size and magnetic characteristics. The magnetic behavior tailored by particle size, ferrite content and calcination temperature enables mixed ferrites to meet the requirements of specific applications in multifunctional materials such as magnetic coatings or thin films.

Concerns regarding product quality and nutrition are raised due to the effects of high temperatures on frying fats. The aim of this research was to examine the effects of temperature and burdock extract addition in relation to quality parameters for dietary lard and goose fat exposed to heating. In order to monitor quality changes, animal fats and 0.01% additivated fats were heated at different temperatures (110, 130, 150, 170, 190, and 210 °C for 30 min). Thiobarbituric acid-reactive substances test (TBARS), peroxide value (PV), iodine value (IV), acid value (AV), saponification value (SV), total polar compounds (TPoC), total phenolic content (TPC), fatty acid (FA) content, and microscopic examination were established in order to quantify the level of oxidative rancidity. Heating temperature and additivation had a significant (p < 0.001) effect on peroxide value. In all fats, values of thiobarbituric acid-reactive substances significantly (p < 0.001) increased with heating temperature, but values decreased when burdock extract was added in a proportion of 0.01%. Positive correlations were found between AV and PV for lard (r = 0.98; p < 0.001) and goose fat (r = 0.96; p < 0.001). The heating temperature had a significant effect on total MUFAs in both lard and goose fat (mostly in non-additivated fat). Statistical analysis of the data showed that the addition of burdock extract at a concentration of 0.01% significantly (p < 0.01) reduced the installation of oxidation process in alimentary fats heated at different temperatures. Animal fats were well protected from oxidation by burdock extract, which demonstrated its efficacy as an antioxidant; it may be used to monitor the fats oxidation and to estimate their shelf-life stability.

Developing innovative nanomaterials unlocks new opportunities in physics, chemistry, medicine, and environmental protection [...].

Chemical data compiled from field and laboratory studies were analysed on drinking water sources from a mountain area (Gutai Mountains) in Romania. Six physico-chemical indicators, nine anions, and twenty-one metals were determined and analysed. The results of this study showed that waters are generally rich in NH4+ and NO2−, exceeding the recommended limit of 0.5 mg NH4+/L, while some waters are rich in As, Cd, Mn and Pb, but with concentrations below the limits concerning the use of waters with drinking purposes. The applied heavy metal pollution indices (scores: 0.56–47.9) indicate that more than 50% of samples are characterized by medium pollution degrees. Based on the results obtained, it was determined that geological and human activities were influential in enriching the studied waters with the chemicals considered. Emphasizing this aspect related to pollution sources and the importance of a clean chemical status that must characterize waters used for drinking purposes, a human health risk assessment for heavy metals was implemented. The results indicated that even though the studied waters are rich in heavy metals, scores related to the risk assessment of heavy metals indicated a lack of non-carcinogenic risks for As, Mn, Cd and Cu. Nevertheless, this study and the results obtained are significant at national and international levels by offering a perspective on determining the potential pollution and associated human health risks at heavy metals in drinking water sources from a mountain area.

Co-doped ferrites are promising functional materials for many practical applications and their physical properties can be tailored by changing their composition. This study assesses the structure, morphology and magnetic properties of CaxCo1-xFe2O4/SiO2 (x = 0.0-0.5) nanocomposites (NCs) obtained by sol-gel method and annealed at different temperatures (400, 800 and 1200 degree celsius). The effect of Ca2+ doping on the properties of nano-structured Ca-Co ferrite embedded in the SiO2 matrix was investigated by thermogravimetry and differential thermal analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller surface area, inductively coupled plasma optical emission spectrometry, atomic force microscopy (AFM) and magnetic measurements. The thermal analysis showed the formation of metal succinates up to 200 degree celsius and of ferrite above 280 degree celsius. The presence of poorly crystalline ferrite accompanied by silicates at low annealing temperatures and of highly crystalline ferrite accompanied by SiO2 and Ca silicates at high annealing temperatures was identified by XRD. The increased Ca2+ doping led to a decrease in the structural parameters estimated by XRD and the surface area. The AFM images revealed that the NCs have a crystalline core covered by a layer of amorphous SiO2. The hysteresis loop shape indicated the superparamagnetic-like and ferromagnetic behavior of the obtained NCs. The magnetic properties improved with the increase in annealing temperature and depended on the particle size and dopant content. The NCs with low Ca2+ content annealed at 800 degree celsius still show appreciable hysteresis, but doping with high Ca2+ contents drastically affects the magnetic properties.