High Concentrations Of Manganese Research Articles

Removal of Fe and Mn from the groundwater by using zeolite with Rossellomorea sp.

Groundwater is one of the alternatives to surface water that can be used for drinking water; however, it normally exists with high iron and manganese content. In this study, a column study was conducted to observe the elimination of iron (Fe) and manganese (Mn) in the groundwater under different retention times by using zeolite immobilised with iron-oxidising bacteria (IOB). Rossellomorea sp. representing an IOB, was found from the isolation process and was further cultured in the laboratory for immobilization into the natural zeolite as replacement materials for the sand filter. When the zeolite assisted with the Rossellomorea sp. was used, the elimination of Fe and Mn were 99.34% and 88.92%, respectively, compared to the removal of Fe and Mn, which were 93.62% and 93.73%, respectively, for media without immobilization. The presence of Rossellomorea sp. enhances the Fe oxidation, resulting in high removal of Fe. The Thomas and Yoon-Nelson models were performed in both raw zeolite and zeolite with IOB. The total coliform (MPN) increased from 70.8 to 307.6 MPN/100 mL due to the Rossellomorea sp. present that promotes the growth of coliform bacteria. In conclusion, the immobilization of zeolite with IOB is a potential technique to extract the Fe and Mn in the groundwater.

Utilization of the Whole Cowpea Pod and Barley Husk in The Production of Nutritionally Enriched Composite Flour

Background: Cowpea is a climbing annual crop from Fabaceae family which is grown for its edible seeds and pods. Cowpea is rich in various nutrients such as fibre, protein, iron, potassium and is low in fat and calories. It has been observed that non-Communicable diseases are increasing at a rapid rate in India as well as globally. The need of the hour is to control the rate of diseases through modification in dietary practices. This study has focused on formulation of whole cowpea pod enriched composite flour by including more fibre and various nutrients in the diet. Methods: In the study, composite flour using whole cowpea pod flour, barley husk flour and whole wheat flour was developed. The nutritional characteristics of composite flour and barley husk were analyzed. Storage study with two different packaging materials was also done. Result: The composite flour was found to have good nutritional properties as it contained valuable amount of protein, energy and crude fibre. It was also found that the flour had higher content of iron, magnesium and calcium while barley husk had higher content of manganese. Laminated aluminium pouches found to be more suitable for use as a packaging material.

DETERMINATION OF THE NUTRITIONAL QUALITIES AND MINERALS CONTAINED IN DRIED PRODUCTS FROM DIFFERENT VARIETIES OF TRADITIONAL ROMANIAN APPLES

The aim of this work was to quantify the content of nutritional elements and minerals in dried products from traditional Romanian old apple varieties from Salaj county, with potential for production and introduction into population consumption, as well as establishing shelf life for dried apples without the addition of preservatives, on the technological flow. The apple varieties evaluated were "Jonathan", "Poinic", "Mustos - sample 2", "Summer- not nominally identified", "Winter- not nominally identified", "Mustos - sample 1", "Dulce", as well as 2 mixes with apples "Mix of dried apples (from the Poinic, Mustos, Dulce, Summer, Winter, Ionathan varieties)" and "Summer variety dried apple mixed with dried chokeberry and dried blackcurrant"(contains apples from the "Summer- not nominally identified"). The samples taken in the study continued the skin and pulp of the fruits. The minerals iron, manganese, magnesium, potassium, calcium and sodium were evaluated. The evaluated nutritional indicators were the content of available carbohydrates, energy (Kj/100g, kcal/100g), energy from fats, ash content, fat content, dietary fiber, protein, dry matter, moisture. The evaluated minerals showed significant differences depending on the variety. The variety 'Jonathan' was noted for its high content of iron 8.1 mg/kg. High manganese content was detected in "Jonathan" variety - 2.11 mg/kg and in "Dulce" variety - 3.11 mg/kg. The "Summer- not nominally identified" variety was noted for its high content of sodium 14.4 mg/kg and calcium 276 mg/kg. The "Poinic" variety stood out for its high potassium content 6380 mg/kg. The "Winter- not nominally identified"variety stood out for its high magnesium content of 377 mg/kg. The results indicated the high nutritional potential of apples from old traditional Romanian varieties.

Main reservoir controlling factors and diagenetic evolution of the Xiao'erbulak Formation of Tarim Basin, NW China: A case study of Well KPN1 in Kalpin area

The Cambrian subsalt dolomite in the Kalpin area of the Tarim Basin is an important reserve growth point and strategic replacement area. However, there is a lack of clear understanding regarding the formation mechanism of high-quality reservoirs in this region, which has hindered oil and gas exploration. This study aims to address this knowledge gap by providing a comprehensive description of the rock types and characteristics of the Xiao'erbulak Formation. Microscope observations, geochemical analyses, and interpretations of well logging data from Well KPN1 were used in this analysis. The Xiao'erbulak Formation can be divided into four members, arranged from bottom to top. The relatively high manganese (Mn) content (87–137.7 ppm), oxygen isotope composition (δ18O) with an average value of −6.37‰, and strontium isotope ratio (87Sr/86Sr) with an average value of 0.7109 indicate that dolomitization of the Xiao'erbulak Formation likely occurred during the penecontemporaneous-shallow burial period. The early formation of dolomite contributed to increased reservoir porosity and resistance to compaction during deep burial, which laid the foundation for reservoir formation. The carbon isotope composition (δ13C) of the Xiao 1 and Xiao 2 members exhibit frequent zigzag curves, indicating recurring progression/regression processes. The subsequent development of granular beach facies played a crucial role in reservoir formation in the Xiao 2 Member. Tectonic fractures and penecontemporaneous karstification controlled the reservoir characteristics of the Xiao 3 Member. Furthermore, this study provides an analysis of the diagenetic evolution model of Well KPN1 and examines the impact of diagenetic transformations on reservoir quality. The systematic analysis of downhole data from Well KPN1 serves as a foundational reference for comparative studies with other drilling sites in the area. It also offers valuable guidance for future exploration and deployment strategies in the northwest Tarim Basin.

Total Suspended Solids (TSS) Spatial Distribution of Manganese in Resident Well Impacted by Residential Activity: A Case Study of Medokan Ayu District-Surabaya

TSS (Total Suspended Solid) is an optical turbidity parameter to assess water quality and provide essential information for the water environment. Particularly, the degradation of watersheds creates immense pressure on water quality, especially in arid and semiarid regions. However, concentrations of TTS in water are also due to the effects of pollution, and activities on the surface. Therefore, factual information regarding determining the effective depth of TSS is essential for the estimation of the water column. To address this problem, we collected 100 water samples from 10 different sites of the wells at Medokan Ayu District, Surabaya (Indonesia). To investigate the TSS concentrations. The results showed that the quality of well water for the turbidity parameter did not exceed the standard of clean water quality, where the highest value was found in well 7: 17.97 NTU, for the Manganese parameter in wells that exceeded the quality standard, it was found in Well 2: 1.4 mg/L. , well 5: 1.7 mg/L, well 6: 1.8 mg/L, well 7 : 8.6 mg/L and well 9: 4.3 mg/L. Well TSS parameters that exceed quality standards are found at Well 1: 1,200 mg/L, Well 3: 1,200 mg/L, Well 5: 800 mg/L, Well 6: 1,600 mg/L, Well 7: 1,600 mg/L, Well 8 : 1,200 mg/L, Well 9 : 1,200 mg/L, and Well 10 : 1,200 mg/L. The pattern of distribution of pollution levels using surfer software mapping, three wells have the highest concentrations of Manganese, TSS, and Turbidity found in wells number 6, 7, and 9.

Application of vacuum membrane distillation process for lithium recovery in spent lithium ion batteries (LIBs) recycling process

The feasibility of using vacuum membrane distillation (VMD) for lithium recovery by concentrating the discharged leachate from spent lithium ion batteries (LIBs) recycling process was evaluated. The performance of VMD was compared with that of direct contact membrane distillation (DCMD) in terms of water flux, concentration rate, membrane wetting, and economic feasibility. VMD achieved a higher volume concentration factor (VCF) of 45 compared to the VCF of 25 achieved by DCMD in the LiCl feed solution. In the Li2SO4 feed solution, VMD and DCMD were concentrated to VCF15 and VCF 17, respectively, before wetting occurred. The stability of the MD process was verified using feed solutions containing nickel and manganese, which are cathode materials that can cause scaling even at low concentrations. Low concentrations of nickel and manganese did not significantly affect the maximum VCF or wetting; however, high concentrations of nickel and manganese affected the stability of the MD process. VMD exhibited a higher flux and 32 % lower thermal energy consumption than DCMD. Furthermore, the expected cost of Li2CO3 production with VMD for leachate concentration was $8.31–10.65/kg. The VMD concentration process is a feasible option for recovering lithium from the discharged leachate from spent LIBs recycling process.

Dynamics of land cover changes and condition of soil and surface water quality in a Mining–Altered landscape, Ghana

This study investigated the dynamics of mining effects on land use land cover changes and the chemical and physical characteristics of soil and surface water in the Ahafo mining area in Ghana. Landsat imagery was used to analyze land use-land cover changes (LULC) using a supervised classification technique. Soil samples were collected within 600 m from active mining operations and at depths of up to 75 cm, as well as surface water samples from upstream and downstream of the mine. Atomic Absorption Spectrometry was used to determine the concentration of heavy metals in the soil and water samples. The results demonstrated a significant loss of forest and other vegetation covers, which decreased from 44% to 31% to 8% and 20%, respectively, with corresponding increases in the mining site, mine water, settlement/bare surface, cropland and plantation. Organic matter, organic carbon, exchangeable bases, cation exchange capacity, available phosphorus, and pH were all moderate in the soil surrounding the mine. Except for As (4.027 mg/kg) and Hg (1 mg/kg), all heavy metals found in the soil were within FAO/WHO guidelines. Total Dissolved Solids (TDS) (416.18 mg/L), Total Suspended Solids (55.08 mg/L), Turbidity (54.49 NTU), Ca (84.49 mg/L), Mg (31.97 mg/L), nitrate (10.23 mg/L), and sulphate (606.83 mg/L) in the downstream water were higher than those in the upstream and USEPA/WHO limits for drinking water except for TDS. Because of the geology of the area, there were high concentrations of iron, manganese, and aluminum in the surface water. The results show that mining induced severe land cover changes and impaired surface water and soil quality in the mine's vicinity. The findings have implications for stakeholder education, appropriate community water interventions, and company-community-regulator participatory monitoring to avoid health risk exposure and further water and soil quality and vegetation degradation.

Determination of macro and microelements in stem and leaf parts after harvest of some peanut varieties

This study was carried out to determine the post-harvest macro and micro element contents of some peanut cultivars grown under main crop conditions and to meet the nutritional requirements of the cultivars. The trial was carried out for two years (2015–2016) in the Alahanlı and Toprakkale trial areas of the Oil Seeds Research Institute. According to the results obtained from the experiment; In terms of macro elements, the highest phosphorus content was found in Batem Cihangir variety (0.122%), the highest potassium content was from Brantley (1,299%), the highest calcium content was from Osmaniye-2005 (2.396%), the highest magnesium content was NC-7 (0.851%) and the highest sodium content was obtained from NC V 11 (0.146%). In terms of micro-elements, the highest iron content was obtained from the varieties of Batem 5025, Arıoğlu-2003, Georgia Green, Batem Cihangir, the highest copper content was from the Brantley variety, the highest zinc content was from the Sultan variety, the highest manganese content was from the Batem Cihangir variety and the highest boron content was from the Flower-22 variety. There are limited studies on the nutritional elements of peanuts, and this study will be beneficial for the selection of the desired varieties for breeding, nutrient content, the use of fertilizers by the growers, and the improvement of the yield of the product.

Recycled membrane for drinking water treatment with high iron and manganese concentrations

Membrane recycling by oxidative treatment is one alternative to minimize the impacts of the disposal of end-of-life (EoL) reverse osmosis (RO) membranes. In parallel, iron (Fe) and manganese (Mn) contamination in surface and groundwater is increasing. This study aims to develop recycled membranes that retain dissolved Fe and Mn from water for supply purposes. EoL RO membranes were recycled with sodium hypochlorite (NaClO, 10–12%) solution at exposure dose between 4000−80,000 ppm∙h to produce a recycled membrane with high flowrate and high Fe and Mn rejection. EoL RO treated by 40,000 ppm·h showed water permeability of 54.30 L∙h−1∙m−2∙bar−1 and Fe and Mn rejection of 99% and 65%, respectively. Potability for Mn (> 98%) was enhanced by integrating pre-oxidation stage with NaClO (5 mg∙L−1 of Cl- and pH 8) to the recycled membrane process. Recycled module performance was evaluated for water treatment from Paraopeba River on pilot scale, in continuous operation (51 h) and pressure of 1 bar. At pilot scale, recycled membrane obtained a water permeability of 40.33 L∙h−1∙m−2∙bar−1, like a moderately open ultrafiltration membrane. Fe and Mn removals were > 99% and > 90%, respectively, with high color and turbidity removal efficiency. Membrane recycling cost was predicted to be US$ 4.08/m², and the capital (CapEX) and operating (OpEX) expenditures for the single-household system was US$ 671.18 and US$ 22.52 to m3·day−1 of treated water. Therefore, the recycled membrane was shown to be efficient in removing dissolved Fe and Mn, and it is promising for decentralized water treatment.

Distribution Characteristics and Genesis of Iron and Manganese Ions in Groundwater of Eastern Sanjiang Plain, China

Groundwater resources are an essential component of global water resources. Long-term consumption of groundwater exceeding the standard levels for iron and manganese can lead to chronic diseases, posing a threat to human health. The Sanjiang Plain is the largest swamp wetland area in China and has high levels of iron and manganese in the groundwater, but the cause still needs to be clarified. Based on the results of water quality tests of 41 groundwater samples in the Eastern Sanjiang Plain, this paper analyzes the distribution characteristics and causes of iron and manganese from the perspectives of the original strata environment, redox conditions, pH conditions, and hydrochemical indicator factors in the research area, using statistical methods and GIS technology. The results show that high iron and manganese content in groundwater is prevalent in the Eastern Sanjiang Plain, and the exceedance rate of manganese is higher than that of iron (87.80% and 82.90%, respectively). The primary sources of iron and manganese in groundwater are iron and manganese minerals in the original strata environment. Influenced by factors such as acidic conditions, reducing environment, and rich organic matter, insoluble high-valent iron and manganese oxides are reduced to low-valent and soluble divalent iron and manganese. At the same time, groundwater’s high mineralization and evaporation concentration are conducive to increased iron and manganese content, while the influence of human activities is small.

Social perception of the effects of high manganese concentrations in drinking water in households in the municipality of Guasave, Sinaloa, Mexico.

Las aguas subterráneas del valle del río Sinaloa juegan un papel importante en el abastecimiento de agua para las actividades domésticas en el municipio de Guasave, Sinaloa México, ya que el abastecimiento proviene de pozos y se brinda a la población a través del sistema de tuberías de Distribución. Las autoridades municipales han reconocido que estas aguas contienen distintas concentraciones de manganeso, lo que puede causar problemas de salud en la población. Por lo tanto, el objetivo de este estudio es explorar la percepción del público sobre el daño causado por el manganeso en los hogares como consecuencia del uso de agua con altos niveles de este metal en actividades domésticas.Los resultados indican que aunque el 51,69% de los usuarios desconocen la presencia de manganeso en sus viviendas, sí han notado sus repercusiones, como en depósitos de agua, sanitarios y ropa. También, han observado taponamientos, principalmente en duchas eléctricas (51,05%) y en cañerías de agua (38,13%), y el 29,75% han notado sabores y colores indeseables en el agua. El noventa y nueve por ciento de los encuestados indicaron que prefieren comprar agua embotellada (purificada) para el consumo debido a la confianza que brinda.

Optimization of Mn‐Mg‐Al Mixed Oxides Composition on their Activity towards the Total Oxidation of Aromatic and Oxygenated VOCs

AbstractA series of mixed oxides (Mn‐Mg‐Al) is prepared by coprecipitation via a hydrotalcite route with different manganese ratios. Structural, textural, and redox properties are studied by XRD, N2‐sorption, H2‐TPR, and XPS techniques. MnxMg6‐xAl2‐O mixed oxides (with 0≤x≤6) are tested in the total oxidation of ethanol and toluene, two probe molecules representing respectively oxygenated and aromatic VOCs. Catalysts with higher manganese contents have shown the best catalytic performance for the oxidation of both ethanol and toluene. The surface activity of the materials is mainly related to the presence of manganese species in three different oxidation states (+II, +III, and +IV) in the bulk and on the material's surface. Since high Mn‐content catalysts showed similar physicochemical properties and catalytic activity, Mn4Mg2‐O is selected as the optimal composition of these materials. Furthermore, its aging test is compared to that of noble metal‐based commercial catalysts (Pd/γ‐Al2O3).

Efficient Mn(II) removal mechanism by Serratia marcescens QZB-1 at high manganese concentration.

Manganese (Mn(II)) pollution has recently increased and requires efficient remediation. In this study, Serratia marcescens QZB-1, isolated from acidic red soil, exhibited high tolerance against Mn(II) (up to 364 mM). Strain QZB-1 removed a total of 98.4% of 18 mM Mn(II), with an adsorption rate of 71.4% and oxidation rate of 28.6% after incubation for 48 h. The strain synthesized more protein (PN) to absorb Mn(II) when stimulated with Mn(II). The pH value of the cultural medium continuously increased during the Mn(II) removal process. The product crystal composition (mainly MnO2 and MnCO3), Mn-O functional group, and element-level fluctuations confirmed Mn oxidation. Overall, strain QZB-1 efficiently removed high concentration of Mn(II) mainly via adsorption and showed great potential for manganese wastewater removal.

ANÁLISIS HIDROGEOQUÍMICO DE LA CALIDAD DE AGUAS SUPERFICIALES EN UNA ZONA MINERA EN EL FLANCO OESTE DE LA CORDILLERA OCCIDENTAL DE LOS ANDES

This study used the hydrogeochemical properties of surface waters surrounding a mining project in Peru to compare them with the environmental quality standards established in Supreme Decree 004-2017-MINAM, focusing on category 3 for vegetable irrigation and animal drinking. Physical-chemical, inorganic, microbiological and parasitic parameters were evaluated in lagoons and springs. The results determined the presence of slightly alkaline deposits with a pH of 9.59 and slightly acidic deposits with a pH of 5.33, as well as deposits with high content of iron, manganese, and zinc. To ensure the reliability of the chemical analysis, an ionic balance of the main dissolved cations and anions was performed. The Piper diagram determined the predominant calcic sulfate waters, as well as the presence of a calcic bicarbonate water deposit. On the other hand, the Stiff diagram determined sulfate (SO42-) as the predominant ion. This study concludes that the different stations comply with the environmental quality standards, although deposits with high levels of iron, manganese, and zinc were found in surface waters. Different treatments were determined to control pH levels and to decrease the amount of such ions present.

Pharmacognostic standardisation of the leaves of Costus afer Ker Gawl. (Zingiberaceae) and Palisota hirsuta (Thunb.) K. Schum. (Commelinaceae)

BackgroundMicrobes’ resistance to orthodox drugs and continued emergence of new infections call for search of new drugs that can mitigate such resistance and cure newly emerging infections. Despite the therapeutic importance of Costus afer and Palisota hirsuta, the detailed pharmacognostic characters of the two plants are still missing in the literature. Thus, this study evaluated the pharmacognostic characters of these plants and the antimicrobial activity of the plants’ methanol extract. Macroscopic, microscopic, fluorescence analysis, phytochemical screening, heavy metal analysis, proximate, antimicrobial assay and Gas Chromatography–Mass Spectrometry analyses were carried out on both plants.ResultsThe microscopic evaluation showed that the epidermal layer of Costus afer is hypostomatic with polygonal shaped epidermal cells and cyclotic stomata on abaxial layer while the epidermal layer of Palisota hirsuta leaf is amphistomatic, having polygonal shape epidermal cell, trichomes and paracytic stomata. The proximate analysis showed that both plants have a high carbohydrate content (C. afer: 59.13% and P. hirsuta: 68.28%) but a low crude fat content (C. afer: 1.867% and P. hirsuta: 0.233%). The heavy metal analysis revealed a high content of Manganese (266.80 mg/100 g) in Palisota hirsua, and a high content of iron (43.94 mg/100 g) in Costus afer. Both plants are free of lead. The phytochemical screening showed that both plants have saponins, tannins, flavonoids, alkaloids and cardiac glycosides. Alkaloids are the highest constituents in Costus afer (9.1%) and Palisota hirsuta (7.1%). The antimicrobial assay showed both plant extracts had the highest inhibitory effect on both bacteria and fungi at 100 mg/kg. Six compounds and 23 compounds were identified by GC–MS in C. afer and P. hirsuta, respectively. Methyl stearate (40.43%) and hexadecanoic acid, methyl ester (25.62%) were the prevailing constituents identified in C. afer and P. hirsuta, respectively.ConclusionThe pharmacognostic features of Costus afer and Palisota hirsuta shown in this study can be used to design a suitable monograph which would be useful in compilation of another edition of Nigeria Herbal Pharmacopoeial. The dominant compounds in both plants can serve as chemotaxonomic markers for correct identification of the two plants.

Optical and photoelectrical properties of low-concentration-Mn-doped CsPbBr3 nanocrystals

Doping of cesium lead bromide (CsPbBr3) perovskite nanocrystals offers effective control of their optical and optoelectrical properties, leading to possibilities of several new applications. Herein, cesium lead bromide perovskite nanocrystals are synthesized with doping of a low concentration of manganese (Mn) into the perovskite lattice using manganese (II) chloride (MnCl2) as a precursor. The shift in X-ray diffraction peaks toward higher angles indicates that manganese as a dopant is present inside the cesium lead bromide lattice. A change in the manganese (II) chloride precursor concentration from 5 to 10 mmol results in an increment in the atomic percentage of manganese from 0.3 to 0.5% in the cesium lead bromide crystal. Doping of a low concentration of manganese (0.3 at.%) into cesium lead bromide results in enhancement of green emission, while doping with a higher concentration of manganese (0.5 at.%) results in blue emission. The band gap of cesium lead bromide nanocrystals increases from 2.31 to 2.53 eV with an increase in the concentration of manganese. The dark and photoelectrical conductivity of cesium lead bromide nanocrystals is improved in the case of doping with a low concentration (0.3 at.%) of manganese. The ratio of photocurrent against dark current is found to be ∼182 in manganese-doped cesium lead bromide crystal film as compared with ∼101 for undoped cesium lead bromide crystal film. Doping with a low concentration of manganese improves the overall electrical and photoelectrical conductivity of cesium lead bromide perovskite nanocrystals.

Facilitation of phosphorus acquisition by Banksia attenuata allows Adenanthos cygnorum (Proteaceae) to extend its range into severely phosphorus-impoverished habitats

Abstract Background and aims In extremely low-phosphorus (P) environments, most Proteaceae exude carboxylates from cluster roots. These carboxylates mobilise inorganic P which leads to a relatively high leaf manganese concentration ([Mn]). However, we found that Adenanthos cygnorum (Proteaceae) in a low-P habitat did not invariably have a high leaf [Mn] in south-western Australia. We aimed to explore how A. cygnorum acquires P in severely P-impoverished habitats. Methods We determined soil P concentrations and leaf [Mn] of A. cygnorum growing within 1 m and more than 10 m away from other large Proteaceae. We also grew plants in a glasshouse to determine its root carboxylate exudation and rhizosheath phosphatase activity. Results Adenanthos cygnorum did not produce functional cluster roots. It depended on carboxylates released by a P-mobilising neighbour, Banksia attenuata (Proteaceae), to acquire P when growing in severely P-impoverished soil (< 8 mg P kg− 1 dry soil). In slightly less P-impoverished soil (> 11 mg P kg− 1 dry soil), phosphatases released by A. cygnorum hydrolysed sufficient organic P that was relatively mobile. Conclusion The reliance on facilitation of P acquisition in A cygnorum depended strongly on location. We demonstrated the exudation of phosphatases, which mobilise inorganic P; this P was adequate for growth when there was sufficient organic P in soil. Facilitation of P acquisition by B. attenuata allowed A. cygnorum to extend its range into severely P-impoverished habitats where it cannot exist without facilitation. This knowledge provides a better understanding of the diversity of P-acquisition strategies in severely P-impoverished environments.

Removing Mn, Cu and Fe from Real Wastewaters with Macrophytes: Reviewing the Relationship between Environmental Factors and Plants' Uptake Capacity.

Heavy metal pollution creates environmental health concerns. Among these, iron (Fe), copper (Cu) and manganese (Mn) are commonly found in aquatic environments due to the release of wastewaters. Phytoremediation in hydroponics uses macrophytes to treat contaminated environments, and this is influenced by environmental factors. However, the relationship between these factors and the removal of Fe, Cu and Mn by macrophytes is not known. Therefore, a meta-analysis serves to determine the correlations between environmental factors and the removal of these metals in real wastewater by macrophytes, as well as to identify the role of different aquatic forms of macrophytes in phytoremediation. Emergent macrophytes had higher concentrations of manganese in their tissues, and higher bioconcentrations factor of iron and manganese than floating plants. Regardless of the biotope, higher concentrations of Fe and Cu decreased the ability of plants to bioconcentrate them. The correlations among exposure time, pH, dissolved oxygen, nitrogen, phosphorus, photoperiod and metal phytoremediation by plants were also found. It can be concluded that the emergent macrophytes showed better performance in terms of the removal of Fe, Cu and Mn, and that the significant correlations between environmental factors and removal vary with the type of metal and the environmental factor analyzed.

Erosion Resistance of Cast Steel and Spheroidal Graphite Cast Iron with a High-Manganese Content in Molten Aluminum Alloys

Erosion Resistance of Cast Steel and Spheroidal Graphite Cast Iron with a High-Manganese Content in Molten Aluminum Alloys

Переработка низкокачественного марганецсодержащего сырья с получением окатышей для производства ферромарганцевых сплавов. Обзор

Substandard ores and technogenic wastes can be considered as an additional source of raw materials due to the limited resources of mineral raw materials with a high content of manganese. The article presents an overview of studies intended to process low-quality manganese-containing raw materials by beneficiation of them with the production of manganese concentrates, agglomeration of manganese fines with the formation of pellets, and smelting of agglomerates into ferromanganese alloys. The main raw material sources of manganese are characterized. Manganese ores are divided into three main types - oxide, siliceous and carbonate ones. The method to beneficiate the raw material is chosen depending on the raw material type. The application areas of manganese alloys are described - they are used in the form of ferromanganese and ferrosilicomanganese to produce steel and cast iron in ferrous metallurgy; as an alloying metal in bronze, brass, most aluminum and magnesium alloys in non-ferrous metallurgy. The beneficiation processes for low-quality manganese-containing raw materials - sub-standard ores and technogenic wastes are considered. A promising direction in the beneficiation of ferromanganese ores is magnetic separation. The extraction of manganese from technogenic sources - ore fines, sludge tailings of processing plants is of great ecological and practical importance. Methods for agglomeration of manganese fines with the production of pellets, briquettes, the influence of the content of acidic and basic oxides, the composition of binder materials on the properties of pellets are described. Data on the influence of various factors on the manganese ferroalloy smelting process, the reduction of manganese ore pellets, and the phase transformations occurring during the process are specified.