Manganese Content Research Articles

Organic pollutant oxidation on manganese oxides in soils – the role of calcite indicated by geoelectrical and chemical analyses

Abstract. Understanding phenolic-pollutant interactions with soil colloids has been a focus of extensive research, primarily under controlled conditions. This study addresses the need to explore these processes in a more natural, complex soil environment. We aim to shed light on the underlying mechanisms of hydroquinone (a representative phenolic pollutant) oxidation in ambient, MnO2-rich sandy soil within soil columns designed for breakthrough experiments. Our innovative approach combines noninvasive electrical measurements, crystallographic and microscopic analyses, and chemical profiling to comprehensively understand soil–pollutant interactions. Our study reveals that hydroquinone oxidation by MnO2 initiates a cascade of reactions, altering local pH, dissolving calcite, and precipitating amorphous Mn oxides, thereby showcasing a complex interplay of chemical processes. Our analysis, combining insights from chemistry and electrical measurements, reveals that the oxidation process led to a constant decrease in polarizing surfaces, as indicated by quadrature conductivity monitoring. Furthermore, dynamic shifts in the soil solution chemistry (changes in the calcium and manganese concentrations, pH, and electrical conductivity (EC)) correlated with the non-monotonous behavior of the in-phase conductivity. Our findings conclusively demonstrate that the noninvasive electrical method allows real-time monitoring of calcite dissolution, serving as a direct cursor to the oxidation process of hydroquinone and enabling the observation of chemical interactions in soil solution and on soil particle surfaces.

Tracking the Dispersal of River Water, Atmospheric Deposition, and Shallow Sedimentary Trace Metal Inputs From the Congo Region Into the South Atlantic

AbstractRecent work has revealed the presence of an offshore near‐surface plume of dissolved trace elements in the South Atlantic Ocean (SAO). Dissolved Fe (dFe) supply from the Congo plume is equivalent to ∼40% of the annual atmospheric dFe supply to the SAO. However this plume is not captured by biogeochemical models, raising questions about its exact sources. To help understand the potential source mechanisms, we use particle tracking experiments to investigate elemental distributions. Results suggest that elevated concentrations of some elements in the Congo plume are primarily sourced from river discharge and wet atmospheric deposition with minimal influence from shelf sediments. River discharge is the main source in shelf regions and some off‐shelf regions, whereas atmospheric deposition dominates the area to the southwest of the Congo River outflow. A quantitative analysis along 3S specifically for dFe suggests a decrease in the contribution of river discharge from 90% to 30% moving off‐shelf, with a corresponding increase in the contribution of atmospheric deposition. Within the shelf zone, atmospheric deposition accounts for roughly 20%–40% and could be a major source of dFe around the river mouth. Integration of data from cruise GA08 reinforces the finding that wet deposition augments the concentrations of dFe, manganese (dMn), and cobalt (dCo) at distances over 1,000 km from the river mouth. Given present‐day patterns of nitrate, Fe, and Co limitation for primary producers in the SAO, changing rainfall patterns may have long‐term implications for both regional elemental budgets and ecologically dependent processes sensitive to trace element ratios.

Exploring The Physiological Response Of Three Barley (Hordeum vulgare) Cultivars To Cadmium Stress

Barley is one of the world’s earliest domesticated crops, ranks fourth grain cereal after maize, rice and wheat. Cadmium (Cd) is a widespread, non essential and toxic heavy metal pollutant reflecting toxicity for both plant and animals. Here, we made an effort to investigate the responce of three barley cultivars using various cadmium dosage. 0, 25-50 µM Cd, 100 µM Cd and 150 µM Cd were taken as different cadmium doses. Results of this study revealed that decrease in shoot length and weight was observed with the increase in cadmium dose. Sentosa and Tarm 92 were found most succeptible and resistant cultivars of barley respectively. Decrease in chlorophyll and proline contents were observed with an increase in cadmium dosage. Higher cadmimum accumulation was observed in root tissues. Effects of cadmium stress were observed for various mineral contents in these cultivars and an increse in calcium contents was also observed. Manganese, copper and zinc content of seedlings increased against low cadmium dosage. However, decrease in the concentration of these mineral was observed against higher Cd dosage. We are confidant that findings of this study will be helpful for the understanding of how cadmium toxicity effects the growth and yield of crops

Sebaran Potensi Mata Air dan Kearifan Lokal Masyarakat dalam Rangka Upaya Konservasi Sumber Daya Air di Kecamatan Akabiluru Kabupaten Lima Puluh Kota

The need for water is very important for life, both agriculture, industry and daily life, causing people to have to look for existing sources to meet their water needs. This study aims to analyze the location of existing water sources and determine the feasibility of water sources by conducting laboratory tests, after that to maintain water sources, community cooperation is needed, one of which is the form of local wisdom in maintaining water sources in Akabiluru District. The method used is descriptive quantitative. The results of the study stated that there are 22 springs spread across Akabiluru District, laboratory tests were carried out with samples of 3 springs, namely Luak Napa, Luak Canduang, Pancuran Duo. The three springs showed good physical water quality, colorless, tasteless and odorless. Meanwhile, the results of the chemical parameter laboratory tests, the water pH is normal except in Pancuran Duo with a pH of 6.1 and the manganese content does not exceed the standard, the mineral content such as calcium, potassium, and magnesium does not exceed the maximum levels allowed according to the drinking water quality standards, and for the microbiological parameters, the coliform content is quite high in the three samples, namely >.2400 MON / 100 ml and 43 MPN / 100 ml. Local wisdom in Akabiluru District in maintaining existing springs is still carried out in several villages such as prohibiting taking water at noon, cleaning springs, and making several water sources sacred springs.

Concentrations of trace metals in serum: Implications for type 2 diabetes mellitus and gender difference

Trace metals play a pivotal role in maintaining normal and healthy physiology due to their various metabolic functions in humans. This study was performed to identify the association between trace metals and type 2 diabetes mellitus (T2DM) through a comparative analysis of serum samples from both healthy controls and T2DM patients. Additionally, we aim to explore the potential connection between gender differences and the concentration of trace metals in T2DM patients. The study included 103 participants, comprising 53 healthy controls and 50 T2DM patients, with blood samples stored at Eulji University Hospital (Daejeon, Korea). Serum concentrations of copper (Cu), zinc (Zn), manganese (Mn), and selenium (Se) and chromium (Cr) levels were measured and statistically analyzed by t-tests and logistic regression after the outliers replaced by mean. In the overall participants, serum concentrations of Cu and Mn in T2DM group was significantly different compared to the control group (P < 0.01). Logistic regression analysis indicated that Cu, Se and Mn concentration was significantly different in T2DM patients than in healthy controls in adjusted for age and sex. When examining trace metal concentrations by gender difference, Se were significantly lower in T2DM men (P < 0.01), while T2DM women exhibited significantly higher levels of Zn, Se and Mn (P < 0.05). Especially in women, logistic regression analysis indicated that Cu, Se and Mn concentration was significantly different in T2DM patients than in healthy control (adjusted for age OR of Cu, 0.92; 95 % CI 0.87 - 0.98, adjusted OR of Se, 3.04; 95 % CI, 1.71 - 5.34; adjusted OR of Mn, 4.50; 95 % CI, 2.09 - 9.68). This study showed that trace metal imbalances related to Se and Mn in patients with T2DM were particularly relevant in women. It highlights the significance of gender difference and suggests the potential benefits of regular monitoring of trace metal concentrations in the management of T2DM patients.

Phase Transitions and Structural Evolution of Manganese Ores During High-Temperature Treatment

The aim of this research is to investigate the phase composition and structural peculiarities of complex metamorphic manganese ores from Central Kazakhstan before and after sintering in the temperature range of 600–1200 °C in an air atmosphere. X-ray diffraction, X-ray fluorescence, scanning electron microscopy, and optical microscopy were used to analyze changes in elemental and phase composition. In their initial state, according to XRF analysis, the Bogach ore was manganese-rich, with a manganese content of 60.77 wt.%, while the Zhaksy ore contained manganese (44.88 wt.%), silicon (20.85 wt.%), and iron (6.14 wt.%) as its main components. In the Bogach ore samples, manganese content increased from 60.77% to 65.7% as the sintering temperature rose to 1100 °C, while the hausmannite phase (Mn3O4) emerged as the dominant phase, comprising 95.77% of the crystalline component at 1200 °C. Conversely, the Zhaksy ore samples displayed a sharp increase in braunite-phase (Mn7O12Si) content, reaching 83.81% at 1100 °C, alongside significant quartz amorphization. The degree of crystallinity in Bogach ore peaked at 56.2% at 900 °C but declined at higher temperatures due to amorphous phase formation. A surface morphology analysis revealed the transformation of dense, non-uniform particles into porous, granular structures with pronounced recrystallization as the temperature increased. In the Bogach samples, sintering at 900 °C resulted in elongated, needle-like crystalline formations, while at 1200 °C, tetragonal crystals of hausmannite dominated, indicating significant grain growth and recrystallization. For Zhaksy samples, sintering at 1100 °C led to a porous morphology with interconnected grains and microvoids, reflecting enhanced braunite crystallization and quartz amorphization. These findings provide quantitative insights into optimizing manganese oxide phases for industrial applications, such as catalysts and pigments, and emphasize the impact of thermal treatment on phase stability and structural properties. This research contributes to the development of efficient processing technologies for medium-grade manganese ores, aligning with Kazakhstan’s strategic goals in sustainable resource utilization.

Heavy Metal Tolerance and Accumulation Potential of a Rare Coastal Species, Anthyllis vulneraria subsp. maritima

The aim of the present study was to explore heavy metal tolerance and accumulation potential in Anthyllis vulneraria subsp. maritima plants from coastal sand dunes in controlled conditions. Plants were established from seeds collected in coastal sand dunes and cultivated in substrates in greenhouse conditions. A gradual treatment with CdCl2, PbOAc, CuSO4, MnSO4, and ZnSO4 was performed until three final concentrations for each metal were reached. The number of leaves, their biomass, and biomass of roots were negatively affected by increasing concentrations of lead (Pb) and manganese (Mn) in substrate, but no negative effect was evident for cadmium (Cd), copper (Cu), and zinc (Zn). Visible effects of metal toxicity were evident for Pb-treated plants (appearance of thinner leaves, yellowing of older leaves), as well as for Mn-treated plants (reduced leaf size, curled leaves, red leaf venation). There was a significant decrease in water content in old leaves at high Pb and increasing Mn concentration, indicating accelerated leaf senescence. Increase in polyphenol oxidase activity in leaves was evident in all the plants treated with heavy metals. In contrast, an increase in peroxidase activity was evident only for plants treated with 50 and 100 mg L−1 Cd, 500 mg L−1 Pb, 200–1000 mg L−1 Mn, and 500 mg L−1 Zn. Metal accumulation potential for Cd and Cu was the highest in the roots, but for Pb, Mn, and Zn, more metal accumulated in old leaves. It can be concluded that A. vulneraria subsp. maritima plants are tolerant to high Cd, Cu, and Zn, but moderately susceptible to Pb and Mn. However, oxidative enzyme activity cannot be unequivocally used as a specific indicator of metal tolerance. In respect to phytoremediation potential, the plants have very good accumulation capacity for Pb, Mn, and Zn.

Оцінка токсичної дії ультрадисперсних частинок порошків феромарганцю і феросилікомарганцю на організм щурів

Introduction. Alloys of iron and manganese (ferroalloys) are traditionally used in metallurgy in the production of steel and various types of cast iron. One of the largest ferroalloy enterprises in Europe operates in Ukraine — the Nikopol Ferroalloy Plant, which produces more than 11% of the world volume of ferroalloys and employs more than 7,500 workers. Industrial production and use of ferroalloys contribute to the entry of their components into the production environment and affect the health of workers. It is known that asthenia, disorders of nervous system and cases of bronchial asthma were registered in workers engaged in ferromanganese melting. There are few data on the effect of ferrosilicomanganese on the human organism. Therefore, the study of the peculiarities of the toxic effect of ferroalloy powders — ferromanganese and ferrosilicomanganese on the organism is a relevant issue for occupational hygiene and industrial toxicology. Aim. Investigation of the peculiarities of the toxic effect of ferromanganese and ferrosilicomanganese powders on the body of rats after a single intratracheal administration during dynamic observation. Materials and Мethods. The experiment was performed on male Wistar rats with an initial body weight of 160–180 g. Suspensions of ferromanganese and ferrosilicomanganese powders in distilled water were administered once into the trachea of animals anesthetized with sodium thiopental at a dose of 50 mg of powder (1/100 LD50) per kg of rat body weight. Control rats were similarly administered 1 ml of distilled water. After administration (in one week, one month and three months), the content of iron, manganese and silicon in the blood of control and experimental rats was determined using the method of atomic emission spectrometry with inductively coupled plasma with the Optima 2100 DV device. Biochemical parameters were determined in all groups of rats (activity of ALT, AST, ALP enzymes; glucose, uric acid, total cholesterol, triglycerides, iron content, serum total iron-binding capacity (TIBC) and percentage of serum iron saturation (TfS), indicators of non-specific natural immunity (phagocytic and bactericidal activity of blood neutrophils, the level of circulating immune complexes (CICs)). Statistical analysis of the data was performed using Microsoft Excel 2007. Results. A single administration of a suspension of ferroalloy powders into the trachea of rats led to an increase in the content of Fe and Mn in the blood, in particular of the Fe content after the administration of ferromanganese and ferrosilicomanganese at all observation periods, while an increase in the level of Mn was detected after one month. The content of Si in the blood of rats of both experimental groups during the experiment was at the level of control values. It was established that an increase in the Fe content in the blood of experimental rats caused disruptions in its metabolism (a decrease in blood TIBC and an increase in the TfS percentage). 3 months after the administration of the powders, an increase in the activity of enzymes (ALT, AST, and ALP) was determined in the blood serum of both experimental groups of rats, as well as an increase in the content of uric acid, which may indicate damage to liver cells and the development of the inflammatory process. With the administration of both ferroalloys, a decrease in the phagocytic function of blood neutrophils and an increase in the formation of reactive oxygen species, an increase in the levels of low- and high-molecular weight CICs in the blood serum, especially one month after the administration, were determined, which indicates the activation of the humoral link of non-specific natural immunity against the background of a violation of the phagocytosis process. Conclusion. The established changes in biochemical and immunological indicators testify to the existing toxic effect on the body of ferromanganese and ferrosilicomanganese powders after their single administration into the trachea, and are caused by an increase in the content of Fe and Mn in the blood of experimental rats. The most pronounced changes were detected one month after the administration of both powders. More adverse effects on the body of experimental rats were caused by ferromanganese powder, the particles of which were smaller. Keywords: ferromanganese, ferrosilicomanganese, ultra disperse particles, toxicity.

Associations of Essential and Non-Essential Trace Elements' Levels in the Blood, Serum, and Urine in Women with Premature Ovarian Insufficiency.

Premature ovarian insufficiency (POI) is poorly understood, with causes identified in only 25% of cases. Emerging evidence suggests links between trace elements (TEs) and POI. This study is the first to compare concentrations of manganese (Mn), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo), arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) across urine, serum, and whole blood in women with POI compared to healthy controls (HC), aiming to explore their distribution and potential associations with POI. This cross-sectional-case-control study enrolled 81 participants (40 POI patients and 41 healthy controls) at the University Medical Centre Ljubljana, Slovenia. Blood and urine samples were collected to quantify basic biochemical parameters using standard clinical chemistry methods and concentrations of Mn, Cu, Zn, Se, Mo, As, Cd, Hg, and Pb using inductively coupled plasma-mass spectrometry (ICP-MS). Participants also completed questionnaires on socio-demographics, medical history, lifestyle, and nutrition. Data was analyzed using the Mann-Whitney U test, Student's t-tests, Fisher exact test, logistic regression models adjusted on body mass index (BMI), age, hematocrit, and Kendall's tau correlation. Women with POI had significantly higher BMI and red blood cell (RBC) indices, including hemoglobin, hematocrit, and red cell distribution width (RDW), compared to controls. A larger proportion of POI patients resided in rural agricultural areas. Liver and kidney function assessments showed no significant differences between the groups. Adjusted models revealed that POI patients had significantly lower urinary levels of Cu, Zn, Se, Mo, Cd, Hg, and Pb than controls, while whole blood Mn levels were higher. Serum Cu levels were significantly elevated in POI patients, whereas Pb, Cd, and Hg were lower. No significant differences were observed for As. Correlation analysis showed several strong to moderate associations among TEs across biofluids, but only weak correlations were found between TEs and demographic or biochemical factors. This study suggests potential associations between TEs and POI in women. Notably, most TEs (Zn, Se, Cu, Mo, Cd, Hg, Pb) were significantly lower in the urine of the POI group, while Cu, Cd, Hg, and Pb showed significant differences in both urine and serum.

Influence of Plant Additives on Changes in the Composition of Fatty Acids, Lipid Quality Indices and Minerals of Fermented Dairy Products from Cow's Milk.

The aim of this study was to assess the effect of selected plant additives on changes in the content of fatty acids, lipid quality indicators and mineral composition of yogurts produced from cow's milk. The analysis included natural yogurts and yogurts enriched with 10% of chia seeds, hulled hemp seeds, quinoa seeds and oat bran. The fatty acid composition, the content of lipid quality indicators and the content of mineral components was varied in all analyzed yogurts. The plant additives used caused significant (p ≤ 0.05) changes in their fatty acid content, i.e., a significant decrease in the content of saturated fatty acids (SFAs) and short-chain fatty acids (SCFAs), and a significant increase in the content of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). The plant additives used caused significant (p ≤ 0.05) changes in the content of fatty acids, i.e., a significant decrease in the content of saturated fatty acids (SFAs) and short-chain fatty acids (SCFAs), and a significant increase in the content of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs). It was shown that additives such as chia seeds and peeled hemp seeds caused the greatest changes in the analyzed yogurts. Yogurts with these additives were characterized by a significant increase in the content of polyunsaturated fatty acids (PUFAs), including n-3 acids, and a more favorable n-6/n-3 ratio. Yogurts with these additives were also characterized by significantly (p ≤ 0.05) lower atherogenic (AI) and thrombogenic (TI) indices and a higher hypocholesterolemia-to-hypercholesterolemia ratio (H/H). The addition of peeled hemp seeds caused the greatest changes in the content of minerals. Yogurts with hemp seeds were characterized by the highest content of all measured macroelements, as well as copper, iron and zinc. In turn, the highest manganese content was determined in the yogurts with the addition of chia seeds.

Arsenic, manganese, and iron concentration in groundwater of northwestern part of Bangladesh using self-organizing maps: Implication for health risk assessment.

Quantification of the non-linear relationship between arsenic (As) and physico-chemical parameters in groundwater through a Self-Organizing Map (SOM) was performed for the first time in Chapai-Nawabganj, Bangladesh. Due to the continuous assessment of groundwater quality, the spatial distribution of As with associated elements was observed for the aerial extent of contaminated groundwater. The results exhibited that 57% and 31% of groundwater samples (n=35) exceeded the allowable limit of As according to the WHO recommended drinking water standard (10μg/L) and Bangladesh Drinking Water Standard (BDWS) (50μg/L), respectively. The spatial distribution map of As demonstrated that a higher concentration of As in groundwater was found in the central portion of the study area and less amount was observed in the eastern part. Whereas 83% of the samples for iron (Fe) concentration in groundwater surpassed the WHO guideline limit (0.3mg/L) and were distributed all over the area except in the central part. Moreover, manganese (Mn) concentration varied from place to place within the allowable limit of WHO. The SOM analysis elucidated the non-linear relationship of As with other elements in two-dimensional planes of having 49 nodes (7×7), which incorporated with Spearman's correlation coefficient quantified the positive correlation among As, Mn and Ca, and negative correlation among As, Fe, EC and pH. In accordance with human health risk was also explained in terms of non-carcinogenic and carcinogenic risk. Health risk assessment demonstrated that higher health hazard (HQ) values in 57% of the samples exceeded the threshold value for adults through the oral route, which implied the potential non-carcinogenic health risk, while 63% of the samples for cancer risk (CR) was higher than the allowable limit indicating the considerable cancer risk zone for the residents of the area. This analysis provides information to the planners for formulating effective groundwater resources management and minimizing health sustainably.

Effects of pristine and photoaged tire wear particles and their leachable additives on key nitrogen removal processes and nitrous oxide accumulation in estuarine sediments.

Despite growing attention to the environmental pollution caused by tire wear particles (TWPs), the effects of pristine and photoaged TWPs (P-TWPs and A-TWPs) and their TWP leachates (TWPLs; P-TWPL and A-TWPL) on key nitrogen removal processes in estuarine sediments remain unclear. This study explores the responses of the denitrification rate, anammox rate, and nitrous oxide (N2O) accumulation to P-TWP, A-TWP, P-TWPL, and A-TWPL exposure in estuarine sediments, and assesses the potential biotoxic substances present in TWPLs. P-TWPs reduced the denitrification rate by 17.1 ± 10.0 % and increased N2O accumulation by 28.1 ± 18.7 %. The A-TWPs not only reduced the denitrification rate by 31.3 ± 8.3 % and increased N2O accumulation by 43.1 ± 22.0 %, but also decreased the anammox rate by 22.1 ± 13.3 %. A-TWPs further inhibited the denitrification rate by reducing nitrate reductase activity and the abundance of its gene (narG), while simultaneously decreasing hydrazine synthase activity and the abundance of its gene (hzo), thereby slowing the anammox rate. N2O accumulation after exposure to TWPs and TWPLs was positively correlated with the activity ratio of N2O-producing and N2O-consuming enzymes. Zinc (Zn) release in A-TWPL was 48.5 ± 6.9 % higher than that in P-TWPL, which is a crucial reason for the higher biotoxicity produced by A-TWPs. In addition, the abundance of denitrifying and anammox bacteria closely linked to the Zn, manganese, and arsenic concentrations in the TWPLs. This study provides insights into assessing the environmental risks posed by TWPs to estuarine ecosystems.

Examining the Impact of Microbial Compost from Anaerobic Digestion on Soil Fertility and Maize Crop Nutrient Uptake

This research study was to evaluate the effects of combining microbial compost and mineral fertilizer on soil properties, maize growth, and nutrient uptake. Therefore, after selecting normal soil, 10 kg of soil was placed in each pot. Nine treatments with three replications were applied by using a Completely Randomized Design (CRD) for the study layout. The results revealed that the maximum plant height (101.73 cm), shoot fresh weight (69.36 g), shoot dry weight (128.6 g), root fresh weight (1.68 g), and root dry weight (0.89 g), as well as the highest content of nitrogen (1.66%), the highest phosphorus concentration (1.04%), and the maximum potassium concentration (2.13%) were noted in SF+MM + ½ NPK, while contents of iron (80.2 mg/kg), zinc (98.46 mg/kg), copper (78.66 mg/kg), and manganese (67.7 mg/kg) were also recorded in SF+MM + ½ NPK compared to other treatments. After harvesting maize crops, the lowest pH (7.27), highest EC (0.38 dS/M), and the highest contents of organic matter (1.03%) were recorded in SF+MM + ½ NPK. Maximum nitrogen content in soil (37 mg/kg), phosphorus content in soil (19.7 mg/kg), and potassium content in soil (105.8 mg/kg) were recorded in T8, while maximum contents of iron (4.88 mg/kg), zinc (1.80 mg/kg), copper (0.51 mg/kg), and manganese (1.95 mg/kg) were recorded in SF+MM + ½ NPK. The combination of SF+MM + ½ NPK showed to be the most effective treatment, whereas the usage of compost and chemical fertilizer alone remained the least effective.

The Origin of Synergetic Effect in Mixed Mn-Co Oxide with Spinel Structure for Catalytic Oxidation of CO

In this work, the origin of the synergetic effect in mixed MnxCo3-xO4 oxides with the spinel structure in the CO oxidation reaction was tested. A series of MnxCo3-x oxide catalysts were synthesized by the coprecipitation method with further calcination at 600 °C and varying manganese content from x = 0 to x = 3. The catalysts were characterized using XRD, TEM, N2 adsorption, TPR, EXAFS, and XPS. The catalytic activity of MnxCo3-x oxide catalysts was tested in CO oxidation reactions. The addition of manganese to cobalt oxide results in the formation of mixed Mn-Co oxides based on a cubic or tetragonal spinel structure, a change in microstructural properties, such as surface area and crystal size, as well as local distortions and a decrease in the surface concentration of Co ions and Co in the octahedral sites in spinel structure; it also decreases catalyst reducibility. For all catalysts, the activity of CO oxidation decreases as follows: Mn0.1Co2.9 > Co3O4~Mn0.3Co2.7 > Mn0.5Co2.5 > MnOx > Mn0.7Co2.3 > Mn0.9Co2.1~Mn1.1Co1.9~Mn2.5Co0.5 > Mn2.9Co0.1 > Mn1.7Co1.3 > Mn2.1Co0.9 > Mn1.3Co1.7~Mn1.5Co1.5~Mn2.3Co0.7. The Mn0.1Co2.9 catalyst displays the best catalytic activity, which is attributed to its small crystal size and the maximum surface ratio between Co3+ and Co2+. A further increase in the manganese content (x > 0.3) provokes drastic changes in the catalytic properties due to a decrease in the cobalt content on the surface and in the volume of mixed oxide, changes in the oxidation states of cations, and structure transformation.

Physico-chemical properties and Manganese concentration effects on biochemical activities in cereals crops grown in degraded soil

Physico-chemical properties and Manganese concentration effects on biochemical activities in cereals crops grown in degraded soil

Assessment of Micronutrient Deficiencies in Agricultural Soils of Hasanganj and Auras Blocks, Unnao District, Uttar Pradesh, India: Implications for Sustainable Farming

This study evaluated the status of essential micronutrients in the soils of Hasanganj and Auras blocks in Unnao district, Uttar Pradesh, India, during 2020–2021. A total of 200 surface soil samples from five villages in each block were analyzed for zinc, boron, copper, manganese, and iron content. The findings revealed significant deficiencies, particularly in zinc (39.5%) and boron (32.5%), with potential implications for crop productivity and soil health. The study emphasizes the urgent need for balanced nutrient management and soil-specific fertilizer recommendations to address these deficiencies and support sustainable agricultural practices. These results provide a valuable baseline for future research and policy interventions aimed at improving soil fertility and food security.

Are Trace Elements Provided for Children on Long-Term Parenteral Nutrition Adequate to Meet Their Needs?

Background: We conducted a cross-sectional study to investigate whether children receiving long-term parenteral nutrition (LPN) are at risk of imbalances in selected trace elements. Methods: Serum levels of manganese, zinc, copper, selenium, and iodine were measured in 83 children on LPN and compared with 121 healthy controls. Children with signs of infection or elevated C-reactive protein levels were excluded. Elemental analysis was performed using inductively coupled plasma mass spectrometry (ICP-MS). Results: Manganese and copper levels were significantly lower in the study group compared with controls (p < 0.001) but remained within normal ranges. Iodine levels were also significantly lower in the study group (p < 0.05), though pediatric reference values are lacking. Zinc and selenium levels were significantly higher in the study group (p < 0.001), with median levels within normal ranges in both groups. Zinc, selenium, and iodine levels were higher in patients weighing ≤15 kg (p < 0.001, p < 0.001, p < 0.02). Conclusions: Serum concentrations of manganese, copper, and selenium in the study group remained within normal ranges, even though children weighing over 15 kg received doses below those recommended by scientific guidelines. An iodine intake below 1 μg/kg/day in patients weighing over 15 kg appears insufficient. Patients on LPN required a higher zinc intake than current recommendations.

Clarias Gariepinus Parasites as Bioindicator For Assessing Water Quality in Omi Dam, Kogi State, Nigeria

Studies using host-parasite dynamics as bioindicator of effects and accumulators of heavy metals for assessing environmental quality are still scarce, particularly in developing countries. This study aimed at elucidating the possible use of parasites of fish in monitoring and assessing water quality. 102 samples of 18 species of parasites of Clarias gariepinus were analyzed for copper, lead, manganese, iron, zinc and cadmium concentrations. Heavy metal concentrations were determined using atomic absorption spectrophotometer. Physico-chemical parameters were measured on sites using Hanna instrument. The nutrients and non-toxic constituents of water were also determined using methods by (American Public Health Association, 1999). The data obtained were analyzed using analysis of variance and significant differences accepted at p ≤ 0.05. Duncan Multiple range test was used to compare the heavy metal accumulation in the parasites and sample t- test was used to compare the values of physico-chemical parameters, nutrients and non-toxic constituents of the water. The heavy metal concentrations in parasites of C. gariepinus were in the order of Lead&gt;Cadmium&gt;Copper&gt;Iron&gt;Magnese&gt;Zinc. Bioindicating capacity of parasites were in the order Nematodes&gt;Cestodes&gt;Protozoan&gt;Trematodes. All physico-chemical parameters of the water (pH, temperature, salinity, turbidity, electrical conductivity, total dissolved solid) except dissolved oxygen were within the permissible level of the WHO (2011) permissible limits. The water nutrients except fluoride were within the permissible limits of WHO (2011). The non-toxic constituents were within permissible limits except NH4+ in the control study sites and PO43- in both study sites that was not within permissible limits. This study revealed that parasites can be ideal indicators for both effects and accumulation of heavy metals in aquatic environments. Findings from this study demonstrate the need for an ecosystem friendly approach towards sustainable management of dams and rivers. This will curb aquatic pollution which can directly and indirectly affect the structure and composition of fish parasite communities and also lead to a health risk in people consuming aquatic resources contaminated with heavy metals.

Associations of Serum Manganese, Zinc, Copper, and Selenium Concentrations With Autism Spectrum Disorders in Chinese Children: A Case-Control Study.

Imbalances in several trace elements related to antioxidant function may lead to autism spectrum disorder (ASD)-related physiological dysfunction. Nonetheless, contradictory results have been found on the connection between these elements and ASD, and studies of their joint effects and interactions have been insufficient. We therefore designed a case-control study of 152 ASD children and 152 age- and sex-matched typically developing (TD) children to explore the individual and combined associations of manganese (Mn), zinc (Zn), copper (Cu), and selenium (Se) with ASD. Compared with TD, ASD has lower Zn and Se levels and higher Cu levels. The restricted cubic spline model showed J-shaped non-linearity, L-shaped non-linearity, and positive linearity correlations between Mn, Zn, Cu, and ASD. Zn and Cu were negatively and positively correlated with ASD symptoms, respectively. The superoxide dismutase (SOD) mediated 50.53% and 39.07% of the association between Zn, Se, and ASD, respectively. Bayesian kernel machine regression (BKMR) confirmed a U-shaped correlation between the element mixtures and ASD. Interactions of Mn with the other three elements and Cu with Zn were also observed. Our results confirm that the independent and combined exposure to the four trace elements was associated with ASD, with oxidative stress being an important mechanism. Due to the potential interactions between the elements, further research is needed to explore their involvement in the pathogenesis and progression of ASD from a combined perspective, as well as the beneficial and harmful concentration ranges.

The influence of cultivation technology on the content of trace elements in pea plants

The purpose of the research is to assess the level of accumulation of copper, zinc, manganese, cobalt and iron by peas using various cultivation technologies. The work was carried out in 2020–2023 on chernozem typical of the Kursk region. Four agrotechnologies of pea cultivation were studied, based on various methods of basic tillage: traditional, differentiated, minimal, direct sowing. The copper content was highest in the roots with minimal technology (13.37 mg/kg), in straw and grain – with direct sowing (6.16 and 5.74 mg/kg). The maximum amount of zinc in the roots was provided by traditional technology and direct sowing (34.10 and 34.63 mg/kg), in straw – differentiated (13.35 mg/kg), in grain ‒ traditional and differentiated (28.06 and 28.86 mg/kg) technologies. The highest content of manganese in the roots was with differentiated technology (369.95 mg/kg), in straw and grain – with direct sowing (68.11 and 55.30 mg/kg). The maximum amount of cobalt in the roots was observed with direct sowing (7.05 mg/kg), in straw – with differentiated technology (4.44 mg/kg), in grain – with minimal technology and direct sowing (3.51 mg/kg). The iron content in the roots did not differ significantly with traditional, minimal technologies and direct sowing, and with differentiated, it decreased by 16.3…26.0 mg/kg. In pea straw, the lowest amount of iron was found with differentiated technology (270.27 mg/kg). During direct sowing, the highest concentration of iron in the grain was noted (135.7 mg /kg). The coefficient of biological accumulation of trace elements by grain was higher than by roots and straw. The highest values of this grain index for copper (24.33), manganese (27.68), cobalt (12.14) and iron (9.19) were noted with direct sowing, and for zinc – with differentiated (28.36) and minimal (28.31) technologies.