Nickel Content Research Articles

Concentrations of potentially toxic metals and trace elements in pregnant women and association with birth outcomes: A cross-sectional study in Malawi

Potentially toxic metals and trace elements have been used in Malawi for a long time. However, data on exposure to these elements by susceptible groups like pregnant women and its associations with reproductive health outcomes in Malawi and southern hemisphere is limited. We investigated the concentrations of potentially toxic metals as well as trace elements in pregnant women and assessed the relationship between the levels these elements in maternal blood and sociodemographic factors, dietary habits and birth outcomes. Maternal data was collected from 605 pregnant women. Provider administered questionnaire was used to collect data on maternal sociodemographic factors, life style and immediate birth outcomes. Maternal venous blood samples were collected from 506 pregnant women in southern Malawi between August 2020 and July 2021. An inductively coupled plasma mass spectrometry (ICP-MS) technique was used to analyse maternal blood samples for concentrations of arsenic (As), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se) and zinc (Zn). Maternal age emerged as the primary predictor for Cu (p = 0.023), As (p = 0.034) and Hg (p = 0.013) blood concentrations, followed by area of residence, which had significant impact on Ni (p = 0.024) and As (p < 0.001) concentrations. High maternal blood concentrations of Ni were associated with increased birth weight (p = 0.047), birth length (p = 0.026), head circumference (p = 0.029) and gestational age (p = 0.035). Negative associations were observed between maternal whole blood total arsenic (combining organic and inorganic As) concentration and neonatal birth length (p = 0.048) and head circumferences (p < 0.001). Similarly, higher maternal blood Pb concentrations were associated with smaller head circumference (p = 0.002) and birth weight (p = 0.016). This study demonstrates the need to introduce biomonitoring studies in Malawi and countries with similar settings in the global south.

Synthesis of a hydrological, water chemistry, and contaminants research program in the Peace-Athabasca Delta (Canada) to inform long-term monitoring of shallow lakes

In a multistressor world, evidence-based stewardship of aquatic ecosystems requires long-term monitoring data to understand the timing and magnitude of environmental change and potential causes. At the Peace-Athabasca Delta (PAD; northeastern Alberta, Canada), concern for aquatic ecosystem degradation has triggered renewed and urgent calls by Indigenous, national, and international governance bodies for implementation of a long-term lake monitoring program capable of tracking changes in hydrological conditions and contaminant deposition attributable to major energy projects located upstream, climate change, and other unnatural and natural processes. Challenges imposed by the delta's size, hydrological complexity, inaccessibility of lakes, and other factors, however, have long impeded implementation of a delta-wide lake monitoring program. To address this pressing need, here we review and synthesize results obtained during 7 years (2015–2021) of intensive, multifaceted research at 60 shallow lakes spanning the delta's broad hydroecological gradients to inform an integrated hydrology, water chemistry, and contaminants monitoring program. The research involved systematic, repeated measurements of water isotope composition, water depth variation, water chemistry and turbidity, and metal(loid) concentrations in lake surface sediment and periphytic biofilm. Results reveal marked spatial and temporal variation of hydrological processes and their affects on lake water balance and depth, strong association between hydrological processes and lake water chemistry, and that concentrations of nickel and vanadium (key oil sands indicators) remain within the range of natural variation. Correspondence of generalized additive model trendlines for isotope-derived lake evaporation-to-inflow ratios and water chemistry with climate indices (Pacific Decadal Oscillation, Oceanic Niño Index) demonstrates the sensitivity, and predictability, of lake ecosystem processes in the delta to large-scale climatic patterns. We provide recommendations for field sampling, sample analysis, data display, and integration of information for ongoing monitoring at the PAD. These approaches are readily transferable to other complex landscapes with abundant shallow waterbodies threatened by multiple stressors that may alter hydrological regimes and contaminant delivery.

Uji Analisis Nikel Ore/Ni (Sampel Cek) Menggunakan Metode Press Pellet Berdasarkan Variasi Suhu Pengeringan, Waktu Pengeringan, dan Berat Sampel Timbangan Press

The purpose of the study was to determine the changes in nickel levels as a result of the analysis on the variation in temperature and drying time as well as the weight of press pellet scale samples from one of the same sample types. This research method is in the form of an experiment with a factorial research design from analysis parameters in the form of MC percentage and nickel ore content of Ni element. The results of the analysis showed that drying at 105°C and 125°C achieved a constant MC during a heating time of 5 to 6 hours. Meanwhile, at a temperature of 145-185 degrees Celsius with an interval of 2-6 hours, the MC level has experienced a constant weight of 44.44%. At the same temperature treatment, which is 105oC, different constant times are obtained. This is influenced by the difference in weight between the two samples, namely in the AP/5 and AP/6 range of 0.360 grams, while AP ORI weighs 1.8 kg. The results of the Epsilon 4 reading showed that the variation in drying temperature at 105°C to 185°C and drying time of 3-6 hours affected the nickel ore content in the range of 1.50% to 1.53%, close to the standard value of nickel 1.50%. The lower the temperature and drying time, the humidity level of the sample increases, causing the nickel ore content to decrease, while the higher the temperature and drying time increases the risk of nickel decomposition. The optimum temperature and drying time is 165°C for 2-4 hours. The press sample weight is between 8-14 grams resulting in a stable nickel content at 1.47%-1.50%, with an optimum weight of 10-14 grams for optimal sample thickness and density.

Reduction of limonite ore from South Sulawesi with additive Na2SO4 using carbon monoxide

ABSTRACT This study utilised a selective reduction method to generate ferronickel from limonitic ore, followed by a magnetic separation stage. The research explored the kinetics and the influence of time and temperature on nickel content and recovery. Sodium sulfate was incorporated as an additive, and carbon monoxide (CO) gas served as the reductant in a vertical tube furnace. Magnetic separation employed a permanent magnet set at 500 G. Reduction took place at temperatures of 900°C, 1000°C, and 1100°C, with varying durations from 30 min to 180 min. Optimal recovery and nickel grade were achieved at 1100°C for 180 min, reaching 70.07% and 8.49%, respectively. Increasing the reduction temperature and time correlated with enhanced recovery and nickel grade.

Omics based approaches to decipher the leaf ionome and transcriptome changes in Solanum lycopersicum L. upon Tomato Brown Rugose Fruit Virus (ToBRFV) infection.

The Tomato Brown Rugose Fruit Virus (ToBRFV) is a pathogen that mostly affects plants from the Solanaceae family. This virus severely affects the yield of tomato (Solanum lycopersicum L.) plants, thus creating an urgent need to research the basis of resistance to manage the disease. To understand the molecular basis of resistance, we employed omics-based approaches involving leaf ionomics and transcriptomics to help us decipher the interaction between elemental and nutritional composition and investigate its effect on the gene expression profile upon the ToBRFV infection in tomatoes. Ionomics was used to investigate the accumulation of trace elements in leaves, showcasing that the plants resistant to the virus had significantly higher concentrations of iron (p-value = 0.039) and nickel (p-value = 0.042) than the susceptible ones. By correlating these findings with transcriptomics, we identified some key genes involved in iron homeostasis and abscisic acid pathways, potentially responsible for conferring resistance against the pathogen. From the obtained list of differentially expressed genes, a panel of mutation profile was discovered with three important genes-Solyc02g068590.3.1 (K+ transporter), Solyc01g111890.3.1 (LRR), and Solyc02g061770.4.1 (Chitinase) showing persistent missense mutations. We ascertain the role of these genes and establish their association with plant resistance using genotyping assays in various tomato lines. The targeted selection of these genetic determinants can further enhance plant breeding and crop yield management strategies.

Evaluating the Influence of Nutrient-Rich Substrates on the Growth and Waste Reduction Efficiency of Black Soldier Fly Larvae

Background: The black soldier fly (Hermetia illucens) has emerged as a promising tool in sustainable waste management, owing to its larvae’s ability to efficiently convert organic waste into valuable biomass. Objective: This study investigates the impact of various substrate compositions on the growth, waste reduction efficiency, and bioconversion rate of black soldier fly (BSF) larvae (Hermetia illucens). The aim is to optimize feeding strategies to enhance the effectiveness of BSF larvae in sustainable waste management and protein production. Methods: A controlled experiment was conducted over a 20-day period, using four different substrate types: 100% sludge, 75% sludge + 25% chicken feed, 25% sludge + 75% chicken feed, and 100% chicken feed. Each treatment had three replicates with 100 larvae each. Larval growth metrics, including weight and width, were recorded bi-daily. The waste reduction efficiency and bioconversion rate were calculated based on the remaining substrate weight and larval biomass, respectively. Elemental analysis was performed to determine the impact of substrate type on the accumulation of various elements in the larvae. Results: Significant differences were observed in larval growth, waste reduction efficiency, and bioconversion rates across the different substrates. The 100% chicken feed substrate led to the highest larval growth (M = 0.0881 g/day, SD = 0.0042) and bioconversion rate (M = 7.52%, SD = 0.34), while the 100% sludge substrate achieved the highest waste reduction rate (M = 86.2%, SD = 2.15). ANOVA tests indicated that substrate composition significantly affected these outcomes (p < 0.05). Elemental analysis showed substantial variations in the concentrations of calcium, cadmium, and nickel among the substrates, with the 100% sludge substrate having the highest nickel accumulation (M = 0.2763 ppm, SD = 0.023), significantly different from the other treatments (p < 0.001). Conclusions: The results demonstrate that substrate composition is crucial for optimizing BSF larvae growth and waste reduction efficiency. Nutrient-rich substrates, such as chicken feed, significantly enhance bioconversion rates and larval biomass production, although careful consideration of elemental accumulation, especially heavy metals, is essential for safe application in animal feed.

Methodological insights into soil elemental nickel in typical Karst areas: comprehensive analysis of geochemical characteristics, source determination, and influencing factors.

Excessive levels of Nickel in the soil can compromise the security of agricultural products, posing a threat to health of human beings; therefore, the repair and treatment of Nickel exceeding the standard levels in soil are particularly critical. Although it is crucial that the potential restoration of Nickel in ensuring the security of both soil and farm produce within karst regions., few studies have been conducted on the potential restoration of large-scale Nickel-contaminated soils. In this study, the soil in Wuming, Guangxi, a typical karst area, was comprehensively studied. 12,547 surface soil samples, 134 deep soil samples and 60 soil profiles were collected systematically. The results showed that the Nickel background value of the surface soil was 34.9mg/kg, indicating strong background characteristics and high variability. Principal component analysis showed that soil Nickel was primarily derived from natural sources in the geological background and partly derived from agricultural sources. Analysis of variance showed that the Nickel content of the soil was affected by the parent rock, soil type, soil use type, and topography. In addition, the distribution of Nickel in the soil profile increased exponentially with depth. Therefore, the exponential model and multiple integrals were used to derive the formula for the Nickel potential restoration amount at different depth ranges, and the potential restoration amount of soil Nickel was calculated based on different parent material, soil, and land use types. The formula is reasonable and representative and can provide a theoretical basis for the remediation and treatment of Nickel-polluted soil in karst areas.

Evaluation of Cadmium, Lead, Chromium, and Nickel Content in Various Types of Nuts: Almonds, Cashews, Hazelnuts, Peanuts, and Walnuts - Health Risk of Polish Consumers.

World production and consumption of nuts continue to rise year on year. Nuts, due to their high nutrient content, are becoming increasingly popular among consumers. A potential health risk may result from the consumption of nuts contaminated with metallic trace elements like cadmium or lead. In this research, we measured the content of Cd, Pb, Cr, and Ni in various edible nuts. All elements were detected using the electrothermal atomic absorption spectrometry analytical technique (ETAAS). The study material comprised 69 nut samples including almonds, cashews, hazelnuts, peanuts, and walnuts available on the Polish market. Indicators such as the hazard quotient (HQ) and hazard index (HI) were used to assess the health risk of consumers. The concentrations of elements in all analyzed samples of nuts were as follows: Cd: peanuts > almonds > hazelnuts > walnuts > cashews, Pb: peanuts > almonds > hazelnuts > walnuts > cashews, Ni: cashews > peanuts > walnuts > hazelnuts > almonds, Cr: almonds > cashews & hazelnuts > peanuts > walnuts. Health risk indicators estimated for consumers whose diet is rich in nuts, in which metallic trace elements were recorded, indicate that an unacceptable impact may occur, and the risk of negative health effects (non-cancer) will be moderate to high.

Effect of Nickel Impurities in Pyrite on Catalytic Degradation of Thiosulfate

The effects of nickel content in nickel-bearing pyrite on photocatalytic properties, light absorption properties, and oxidative decomposition of thiosulfate were studied. The leaching experiments show that the consumption of thiosulfate in the Cu2+-ethylenediamine (en)-S2O32− system increases with an increase in nickel content in nickel-bearing pyrite. The consumption of Cu(en)22+ initially increases and then decreases with an increase in leaching time. There is a clear correlation between the change trend in its consumption and the doping amount of nickel in pyrite. The XPS results show that in the Cu2+-ethylenediamine (en)-S2O32− leaching gold system (temperature 25 °C, time 35 h, solution: 0.1 mol/L S2O32−, 5 mmol/L Cu(en)22+, 200 mL solution), the nickel of pyrite-containing nickel can be transferred to the leaching solution and becomes nickel ion. In this leaching system, Cu(II), which was originally complexed with en, is reduced to Cu(I) in a short time. The consumption of Cu(en)22+ increased rapidly in the 5 h period and then decreased gradually after 5 h. The results showed that the presence of free Ni2+ in the solution facilitated the conversion of bivalent copper ions to monovalent copper ions. Free Ni2+ ions can compete with Cu2+ ions for en ligands. When ethylenediamine complexes with Ni2+, the decomposition of Cu(en)22+ into Cu(en)+ and en occurs more rapidly. And the en, which was originally to be oxidized with Cu(en)+ to form Cu(en)22+, forms Ni(en)22+. As a result, the concentration of Cu(en)22+ continues to decrease in a short period of time.

Synthesis of Ni–FeCeO2 by mechanochemical method for high-temperature water-gas shift reaction

Hydrocarbon fuels have caused significant environmental damage, leading to a search for renewable alternatives like hydrogen. The water-gas shift reaction (WGSR) is a key process in hydrogen production, especially in ammonia synthesis. Typically, WGSR occurs in two stages: low-temperature (LT-WGSR) at 180–250 °C and high-temperature (HT-WGSR) at 310–450 °C. Traditional HT-WGSR catalysts use Fe–Cr, but the presence of carcinogenic hexavalent chromium (Cr6+) poses environmental risks, necessitating safer alternatives. This study explores the replacement of chromium with aluminum (Al) and cerium (Ce) in Fe-based catalysts, synthesized via mechanochemical methods. Characterization revealed that Fe–Ce catalysts (85:15 ratio) exhibited superior thermal stability. Additionally, varying nickel (Ni) contents were tested to improve activity, with 10% Ni offering the best performance despite some methane by-products. The study also examined the impact of reduction and calcination temperatures, GHSV, and steam/gas ratios on the catalyst's efficiency.

The Effect of Organic Materials with Different Degrees of Decomposition on the Content of Nickel in the Lettuce Leaves Cultivated in Mineral Soil

Studies were carried out in order to verify the research hypothesis that “the introduction of organic matter in the form of high peat, brown coal, and wheat straw to the mineral soil contaminated with nickel will reduce the content of this metal in the lettuce”, the main purpose of which was to determine the impact of various organic materials with varying degrees of decomposition on the content of nickel in lettuce leaves. The factors of the experiment were different types of organic material that were added to the mineral soil (loamy sand), such as high peat, brown coal, and wheat straw. The substrates in which lettuce was grown were contaminated with increasing doses of nickel: 0, 50, 75, and 100 mg Ni·dm−3 of the substrate. This research shows that the type of organic material introduced into the mineral soil as a source of soil organic meter has a significant impact on the content of nickel in lettuce leaves.

Effect of Contact Time on the Sorption of Metal Ions Associated with Produced Water on Pulverized Oyster Shell (OS) as Adsorbent

The aim of this research is to investigate Metal ion sorption potentials of pulverized Oyster Shell as adsorbent in produced water from selected flow stations in the Niger Delta region of Nigeria. Produced water samples were collected from six (6) different oil drilling installations (CC7T, CC8T, WELL 2 GSS, WELL 8 TEB, AZUZUAMA ST 1, AZUZUAMA ST 2) around the Niger Delta area of Nigeria. The waste oyster shell was collected in Akpan-Andem Market in Uyo, Akwa-Ibom State and processed using well established protocols. Atomic Absorption Spectrometer (AAS) was used to determine selected metals’ Nickel (Ni), Cobalt (Co), Copper (Cu), Iron (Fe), Lead (Pb), Calcium (Ca) and Potassium (K) concentrations. The obtained values for Nickel ranged from 0.076mg/l at AZUZU-AMA ST1 flow station to 2.882 mg/l at WELL2-GSS flow station with average value of 0.745 mg/l. The obtained value for Cobalt ranged from ˂0.001 mg/l at CC-8T and CC-7T to 0.277 mg/l at AZUZUAMA ST1. Values obtained for Cu, Fe, Pb, Ca, and K ranged between: 0.195 mg/l at WELL2-GSS to 0.449 mg/l at AZUZU-AMA ST1; 2.785 mg/l to 89.279mg/l; ˂0.001 mg/l to 0.483 mg/l; 16.217 mg/l to 92.714 mg/l and 96.386 mg/l to 105.416 mg/l respectively. Generally, the amount of metal ions absorbed/adsorbed onto pulverized Oyster shell (OS) increased swiftly within 2 hours and slowly with further increase of contact time and then tended to be stable. For pulverized Oyster shell adsorbent, the adsorption/absorption capacity decreases with the increasing contact time. The adsorbent (OS) isn’t good material for removal of Calcium and Cobalt in produced water but was very effective adsorbent for Ni, Fe, and Pb removal in produced water and less effective for Cu and K removal from produced water. The study underscores the need to further probe outcome of above research at different pH and other relevant variables as well as compares its efficiency with other detoxification technologies like Detoxification by chemical reaction (DCR) technology.

Nickel toxicology testing in alternative specimen from farm ruminants in a urban polluted environment

The impact of nickel (Ni) metal toxicity, on public health was assessed analyzing forage samples (Acacia nilotica, Zea mays, Pennisetum glaucum, Capparis decidua and Medicago sativa), soils and blood samples of cow, buffalo and sheep (blood plasma, fecal, and hair) collected from three different agro-ecological zones and analyzed through atomic absorption spectrophotometer. Results showed that nickel values differed in soil samples ranging from 4.49 to 9 to 25 mg/kg, in forages from 3.78 to 9.53 mg/kg and in animal samples from 0.65 to 2.42 mg/kg. Nickel concentration, in soil and forage samples, was below the permitted limits. Soil with the minimum nickel level was found under C. decidua while the maximum concentration was reached under the A. nilotica. Among the animals, nickel was maximum in buffaloes that grazed on the Z. mays fodder. Ni was more accumulated in feces than other body tissues. The sheep and buffaloes showed high vulnerability to Ni pollution due to the highest contamination levels at site II and III. Bioconcentration factor, pollution load index and enrichment factor were found to be higher in buffaloes than cows, respectively. The daily intake and health risk index ranged from 0.0056 to 0.0184 mg/kg/day and 0.186–0.614 mg/kg/day respectively. In short, the results of this study evidenced that Nickel-containing fertilizers should never not be used to grow forage species. Government should to lessen the toxic metal accessibility to animals. Although general values were lower than the admitted limit, nickel can be accumulated and the consume of food containing nickel can increase health risks. General monitoring of soil and vegetation pollution load, as well as the use of other non-conventional water like canal water for forage irrigation could be a sustainable solution to decrease the access of nickel in the food chain.

Microstructural, magnetic, and optical properties of nickel-doped spinel zinc ferrite nanoparticles

This study focuses on the synthesis of nickel-substituted zinc ferrite nanoparticles, , via the sol-gel method and examines how nickel substitution influences their structural, magnetic, and optical properties. The lattice constant of the nanoparticles, which varied from 8.4296 Å to 8.4212 Å, decreased as the nickel concentration increased. Scanning electron microscopy (SEM) was employed to examine the morphology, revealing grain sizes between 46 and 53 nm, while energy dispersive X-ray spectroscopy (EDX) confirmed the elemental composition, showing nearly spherical nanoparticles containing all the constituent elements. The magnetic properties were analyzed using a vibrating sample magnetometer (VSM), which highlighted significant differences between the theoretical and experimental magnetic moments, indicating the presence of Yafet-Kittel magnetic ordering in the system. The saturation magnetization was enhanced by ions, reaching a maximum value of 23.864 emu/g. This enhancement makes the nickel-substituted zinc ferrite nanoparticles suitable for applications in data recording media and magnetic resonance imaging. Additionally, the values of the magnetic crystalline anisotropy constant, initial permeability, effective anisotropy constant, and anisotropic field of the synthesized samples were estimated.The optical properties of the synthesized samples were evaluated using UV-visible spectroscopy, and the band gap was determined through diffuse reflectance spectroscopy (DRS). The optical bandgap of pure zinc ferrite was measured to be 2.26 eV, and it decreased with increasing nickel concentration in the nanoparticles.

Homogeneous Crystallization of Nickel as Ni₃S₄ in a Fluidized Bed Reactor with Supersaturation Control

This study investigates the recovery of nickel sulfide (NiS) using fluidized bed homogeneous crystallization (FBHC), emphasizing the process from nucleation to crystallization. Sludge production in conventional chemical precipitation becomes a drawback in treating wastewater economically and efficiently. FBHC offers a promising alternative by minimizing sludge generation. The study examines various operational parameters, including hydraulic retention times (HRT), reflux ratio (R), initial nickel concentration, and static bed height (SBH), to optimize NiS recovery. Results show that FBHC achieves high total removal efficiency (TR) and crystallization ratio (CR), under the optimum condition of HRT = 15min, R = 8.3, initial nickel concentration = 147mg/L, and SBH = 35cm. The agglomeration of Ni(OH)2 was found to be crucial for the crystal growth during the surface oxidation of Ni3S4. This technological approach to wastewater treatment offers highly efficient heavy metal removal from wastewater.

Southeastern extension of Singhbhum Shear Zone, Eastern Indian Shield: A detailed appraisal

Trans-crustal, northerly dipping, arcuate Singhbhum Shear Zone (SSZ) constituting the interface of Proterozoic North Singhbhum Mobile Belt (NSMB) and Singhbhum Craton (SC) is established over a strike length of about ∼200 km from Baharagorato Chakradharpur in the west beyond which it bifurcates around the wedge shaped Chakradharpur granite. Based on geological mapping and meso to micro scale structural analysis, present work examines the SSZ’s southeastern extension beyond Baharagora, indicating its southward continuation for about 50 km to Dubukidihi within the NSMB lithopackage. Bangriposi Shear Zone (BSZ) which defines the terrane boundary between the SC and NSMB in this sector, splays towards north as Bangriposi West Shear Zone (BWSZ) and both transects the Dhanjori Basin longitudinally. BSZ and BWSZ are interpreted to be cogenetic with SSZ. NSMB in this area comprises of pelitic and psamopelitic rocks intruded by mafic–ultramafic magmatism and granitoids. Considering a north to south compression regime during accretion of NSMB with SC, the study area, which forms the interface between the craton and mobile belt, is at an acute to obtuse angle with the direction of overall stress field. It is marked by several high strain zones characterized by N-S shear band cleavages with moderate easterly dips, and northerly pitching stretching/mineral lineation. Consistent westerly vergent folds on mylonitic plane and orientation of stretching lineation indicates top to WSW movement in the shear zones. Tectonically interleaved mafic–ultramafic schist within the Romapahari granite are sites of copper mineralization with enhanced nickel concentration pointing towards future exploration sites for epigenetic copper, uranium mineralization which is so characteristic of SSZ.

Monitoring and Assessment of Toxicological Risks of Poultry Meat Contaminated with Heavy Metals.

This study aimed to investigate the heavy metal contamination in poultry meat of Kotli Sattian, Rawalpindi. The meat samples from ten sites were analyzed for lead, cadmium, chromium, copper, arsenic, nickel, zinc, iron, sodium, and calcium. The possible health risks of these metals were also observed. Mean lead, cadmium, chromium, arsenic, and nickel concentrations were higher than the permissible limits of the World Health Organization (WHO). Metals in meat samples showed the trend of Fe > Na > Zn > Ni > Ca > As > Cr > Pb > Cu > Cd. All the studied metals except lead were statistically significant (P ≤ 0.05). The hazard quotient (HQ) values of all the metals were below one, except iron. Iron showed chronic health risks in both adults (1.63) and children (3.64). Moreover, the cumulative hazard index (HI) of the metals indicated that meat consumption can pose a significant chronic toxic risk in both adults and children as the HI value was 2.06 for adults and 4.61 for children, which is greater than one. The carcinogenic risk (CR) of arsenic in meat for adults and children exceeded the acceptable range, making it a metal of concern. This means that the consumption of small concentrations of metal through meat may be the source of severe toxicological consequences. It can be concluded that meat is contaminated with metals; therefore, appropriate precautions should be taken to minimize this contamination.

Effect of the Reactor Material on the Reforming of Primary Syngas

Syngas, mostly hydrogen and carbon monoxide, has traditionally been produced from coal and natural gas, with biomass gasification later emerging as a renewable process. It is widely used in fuel synthesis through the Fischer–Tropsch (FT) process, where the H2/CO ratio is crucial in determining product efficiency and quality. In this sense, this study aimed to reform an emulated syngas resulting from the supercritical water gasification of biomass, tailoring it to meet the H2/CO ratio required for FT synthesis. Conditions resembling dry reforming were applied, using temperatures from 600 to 950 °C and steel wool as a catalyst. Additionally, the effects of Inconel and stainless steel as reactor materials on syngas reforming were investigated. When Inconel was used, H2/CO ratios ranged between 1.04 and 1.84 with steel wool and 1.28 and 1.67 without. When comparing reactions without steel wool performed either in the Inconel or the stainless steel reactors, those using Inconel consistently outperformed the stainless steel ones, achieving CH4 and CO2 conversions up to 95% and 76%, respectively, versus 0% and 39% with stainless steel. It was concluded that the Inconel reactor exhibited catalytic properties due to its high nickel content and specific oxides.

Effects of nickel-deactivations on zeolites-Y of different SiO2/Al2O3 ratios in catalytic cracking of hydrocarbons

Effects of nickel deactivation on catalytic activities of three types of zeolites-Y (Y-5.1, USY-5.2, and VUSY-12) with varying SiO2/Al2O3 ratios were studied in cracking of hydrocarbons. Physicochemical characteristics such as crystalline phases, Ni oxidation states, morphology, acidity, surface area, and thermal stability of the samples were analysed. XRD revealed the absence of observable nickel compounds below 5 wt%, with NiO phase emerging at higher concentrations. Surface areas decreased from 826 to 615 m2/g (Y-5.1), 786–686 m2/g (USY-5.2), and 762–571 m2/g (VUSY-12) at 30 wt% Ni. The total acid sites also reduced from 17.247 to 9.826 µmol/g (Y-5.1), 15.464–8.854 µmol/g (USY-5.2), and 7.094–4.876 µmol/g (VUSY-12). XPS confirmed Ni2+ states. Catalytic cracking tests using n-Heptane demonstrated increases in C5-C6 alkanes, olefins, hydrogen, and methane yields as nickel concentration increased, with respective values of 64 %, 28 %, 79 % and 68 % for Y-5.1; 62 %, 28 %, 76 %, and 62 % for USY-5.2; and 58 %, 21 %, 75 %, and 60 % for VUSY-12. A corresponding decrease in heavier components were observed. The study demonstrates that nickel modification significantly impacts the physicochemical properties and catalytic performance of zeolite-Y and these depend strongly on the SiO2/Al2O3 ratios. The study gives further insights into the structural and catalytic modifications induced by nickel doping in zeolites, highlighting the potential of nickel-modified zeolites in promoting undesirable hydrogen and gas.

Orthodontic Alloy Wires and Their Hypoallergenic Alternatives: Metal Ions Release in pH 6.6 and pH 5.5 Artificial Saliva

Legislative framework addresses the issues of alloy corrosion, demanding the restricted use of probable carcinogenic, mutagenic, and toxic-for-human-reproduction (CMG) metals like nickel, cobalt, and chromium and demanding the development of new biomaterials. The aim of this research was to evaluate and compare the ion release of standard dental alloys and their hypoallergenic equivalents. Six types of orthodontic alloy wires (nickel–titanium (NiTi), coated NiTi, stainless steel (SS), Ni-free SS, and cobalt–chromium (CoCr) and titanium–molybdenum (TMA) were immersed into artificial saliva of pH 5.5 and 6.6. Release of metal ions was measured by inductively coupled plasma–mass spectrometry after 3, 7, 14 and 28 days. The data were analyzed using analysis of variance, and results with p < 0.05 were considered significant. NiTi released more Ti and Ni ions compared to the coated NiTi; SS released more iron, chromium, and nickel compared to the nickel-free SS. CoCr released cobalt in a high concentration and low amounts of chromium, nickel, and molybdenum compared to the molybdenum and titanium released by TMA. Release of metals from dental orthodontic alloys in vitro was overall lower at pH 6.6 and for the hypoallergenic equivalents when compared to standard dental alloys.