Iron Sulfate Research Articles

Физико-химические характеристики нанокомпозитов Fe3O4/TiO2 и Fe3O4/SiO2/TiO2, синтезированных гид-ротермальным пероксидным методом

In the present paper the composite materials based on Fe3O4/TiO2 and Fe3O4/SiO2/TiO2 ox-ides, synthesized by the hydrothermal peroxide method, were studied. At the first stage, magnet-ite nanoparticles were precipitated by ammonium hydroxide from a mixture of aqueous solutions of iron(II) sulfate and iron(III) chloride under continuous exposure to ultrasound, after which they were washed with distilled water. At the second stage, the resulting hydrated magnetite particles were stabilized with polyvinyl alcohol (PVA) by dispersing them under the action of ultrasound in a hot saturated aqueous PVA solution. At the third stage, the photocatalytically active particles based on titanium oxide were introduced into the composite by mixing the stabilized magnetite suspension with an aqueous solution of peroxotitanic acid (optionally introducing a sol of silicic acid), followed by hydrothermal treatment of the mixture at 180°C for 24 hours, washing, and drying under vacuum followed by calcination in a muffle furnace. The effect of the molar content of iron and titanium on the properties of the samples, the introduction of silicon dioxide into them, as well as various calcination temperatures, were studied. The photocatalytic properties of the synthesized samples during photodegradation of methyl orange and methylene blue, as well as their magnetic recovery from suspension, were studied. The physicochemical characterization of the samples was performed using high-resolution scanning electron microscopy, energy-dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, powder X-ray diffraction, low-temperature nitrogen sorption porosimetry, inductively coupled plasma mass spectrometry, thermal analysis (TG–DSC), combined with mass spectrometry of gaseous thermolysis products. The optimal conditions for the synthesis of composites exhibiting the best combination of photocatalytic and magnetic properties were determined. The resulting photocatalysts can be used to purify water from dyes, followed by extraction using a magnet

Synthesis of a cost-effective magnetic nanoparticles coated sugarcane bagasse and testing tetracycline removal capacity

This study describes a modified method to prepare nanomagnetic coated sugarcane bagasse. Under the general chemicals: iron (II) sulphate heptahydrate (FeSO4.7H2O); sodium hydroxide, hydrochloric acid, and iron (III) chloride hexahydrate (FeCl3.6H2O) these were commercially available and a simple method, authors were successfully synthesized Fe3O4 nanoparticles coated sugarcane bagasse. These nanoparticles were heterogenous and formed nanoclusters on the sugarcane bagasse surface under Scanning Electron Microscopy analysis. Herein, we show that given the right experimental circumstances, the novel and prospective nanomagnetic sugarcane bagasse might prove to be an intriguing adsorbent for a variety of applications. For tetracycline removal case study: the studied material was significantly adsorbed this contaminant with the highest adsorption capacity was 15 mg/g under 25 mg/L initial tetracycline concentration; pH 6; equilibrium time: 15 hours; and magnetic nanoparticle sugarcane bagasse: 1 g/L. The fundamental result in the research denotes that the material could be a potential adsorbent for eliminating various contaminants in upcoming studies.

Композитные магнитовосприимчивые фотокатали-заторы на основе оксидов Fe3O4/SiO2/TiO2

In the present study the composite materials based on the Fe3O4/SiO2/TiO2 oxides, synthe-sized by the sol-gel method, were investigated. At the first stage, magnetite nanoparticles were precipitated by sodium hydroxide from a mixture of aqueous solutions of iron(II) and iron(III) sulfates under continuous ultrasonic treatment, after which they were washed with distilled water and dried under vacuum. At the second stage, the resulting magnetite particles were coated with silicon oxide according to the Stober method by dispersing them under the ultrasonic treatment in a solution of tetraethoxysilane in n-propanol, followed by hydrolysis of tetraethoxysilane in the presence of aqueous ammonia, washing and drying the obtained materials under vacuum. At the third stage, photocatalytically active particles based on titanium oxide were introduced into the composite by the solvent replacement procedure via dispersing the samples in an aqueous solution of peroxotitanic acid and adding n-propanol, stirring vigorously, followed by activation based on boiling in the water/ethanol (1:1) mixture, washing and drying under vacuum. The properties of samples influenced by the citrate stabilization and separation of magnetite particles at the stage of their synthesis into “light” and “heavy” magnetic fractions, as well as calcination of samples at 450 °C, were studied. The photocatalytic properties of the synthesized samples were studied during photodegradation of methyl orange, as well as their magnetic extraction from the suspension. The physicochemical characterization of the samples was performed using a high-resolution scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray powder diffraction, thermal analysis (TG–DSC), combined with mass spectrometry of gaseous thermolysis products. It has been found that the composites based on the mixed titanium-silicon oxide have a higher photocatalytic activity than the composites based on the pure titanium dioxide obtained via a similar procedure. The resulting photocatalysts can be used to purify water from dyes, followed by their extraction using a magnet.

Comparison of the Prophylactic Use of Iron Polymaltose Complex and Ferrous Sulfate Iron Preparations in Terms of Efficacy and Side Effect Profile in Pregnant Women

Comparison of the Prophylactic Use of Iron Polymaltose Complex and Ferrous Sulfate Iron Preparations in Terms of Efficacy and Side Effect Profile in Pregnant Women

Kinetic Spectrophotometric Determination of Ascorbic Acid by Using Phenanthroline Agent in Eruca sativa

Ascorbic acid is used for treatment in hypovitaminosis, nutritional deficiency, scurvy, gingivitis, Barlow and Basedow diseases. In this study, a simple and sensitive kinetic spectrophotometric method was developed for the determination of ascorbic acid in Eruca sativa. The rate of formation of the product formed as a result of the reaction of ascorbic acid with iron (III) sulfate and phenanthroline reagents was determined by measuring the absorbance at 510 nm wavelength at 5 minute intervals for 60 minutes. The measurement curve prepared from standard ascorbic acid solution is linear in the concentration range of 4.0-6.0 mg/mL. The regression equation obtained from the graph of logarithms of molar concentrations versus logarithms of slopes was found as log (rate) = 2.5721 logC - 9.461 (r=0.9999) according to the initial rate method. The developed method was applied to Eruca sativa samples and the amount of ascorbic acid in fresh leaves was found to be 72.80 mg/100 g.

INFLUENCE OF CATHODE MATERIAL ON COMBINED CATHODE PROCESSES IN AQUEOUS SOLUTIONS OF IRON(II) SULPHATE

Sulfuric acid is present in many enterprises for metal processing and manufacturing of metal parts. Existing methods of regeneration of spent solutions are not effective, in particular, spent sulfate solutions are neutralized with lye or waste from other industries containing solid carbonates and hydroxides. At the same time, sulfate waste is formed, which requires disposal at special landfills. Electrochemical regeneration of spent solutions of sulfate-acid treatment of steel solves the problem of disposal of such spent sulfate solutions with the inclusion of iron sulfates. The kinetics of combined cathodic processes in aqueous solutions of iron (II) sulfate at a concentration of 0.5 mol.·dm–3 of iron (II) sulfate, depending on the cathode material was studied. The research methodology was as follows: model aqueous solutions with a composition (mol∙dm–3): 0.5 iron (II) sulfate with the addition of 0.5 sulfuric acid and a control solution – 1.0 sulfuric acid were prepared from chemicals of high stage of purification by dissolution in distilled water. The study of the kinetics of combined cathodic processes in model aqueous solutions was carried out by the method of linear voltammetry using the MTech PGP-500 S potentiostat. The auxiliary electrode is platinum. The reference electrode is mercury sulfate. Determination of iron (II) ions in the solution was carried out by the permanganatometric method. Based on the analysis of the obtained current-voltage curves, the effectiveness of the application of electrochemical regeneration of model solutions of iron (II) sulfate with sulfuric acid was established, which makes it possible to cathodically deposit iron in the form of foil or metal powder, and through the course of the anodic process - convert sulfates into sulfuric acid. During this process, oxidation of Fe2+ to Fe3+ takes place at the slightly soluble anode. Therefore, it is proposed to use polymer porous diaphragms to prevent Fe2+ from entering the anode space. Platinum and copper were used as cathode material. The choice of cathode material was based on different electrochemical properties of these metals in relation to the hydrogen reaction. The balance research on the regeneration of the model solution was carried out in a three-chamber electrolyzer. The initial test solution was fed into the middle chamber. The cathodic current density was 0.025 and 0.035 A∙cm–2, the working area of the anode and cathode was 85 cm2. A compact iron deposit was obtained on the cathode with 08X12N10T, which peeled off. The analysis of the cathode deposit showed the presence of 0.065% hydrogen in iron. Output according to the current of iron was 92%. The end of the Tafel section of the course of cathodic reduction of iron with electrochemical control occurs due to Fe2+ concentration limitations and the ohmic resistance of adsorbed hydrogen at the boundary of heterogeneous phases. It is proposed to eliminate these limitations due to electrolyte mixing.

Influence of the Preparation Technique on the Magnetic Characteristics of ε-Fe2O3-Based Composites

ε-Fe2O3 is an iron(III) oxide polymorph attracting an increasing interest due to its unique magnetic properties combining extremely high coercivity and relatively large saturation magnetization. We review existing methods for the ε-Fe2O3 synthesis focusing on synthesis speed, repeatability, manufacturability and purity of the final product. Samples of ε-Fe2O3 have been synthesized using the two methods that appear the most promising: silica gel impregnation and microemulsion. In both cases, ε-Fe2O3 and α-Fe2O3 are present in the final product as attested by X-ray diffraction patterns and magnetic properties (maximum coercive force at 300 K~1 Tesla). Two different precursors, iron(III) nitrate and iron(II) sulfate, have been used in the silica gel impregnation method. Somewhat surprisingly, iron sulfate proved superior yielding ε-Fe2O3 content of 69% in the total iron oxide product, compared to 25% for iron nitrate under the same synthesis conditions. These results pave the way for modifying the existing ε-Fe2O3 synthesis methods aiming to increase the content of the epsilon phase in the final product and, consequently, improve its physicochemical properties.

Dyeing of polyamide 6 fabric with new bio-colorant and bio-mordants.

The present study investigates the natural dyeing of nylon fabric using the dragon's blood resin extract. Response surface methodology was used to optimize the process variables including pH (3-9), temperature (50-100°C), concentration (10-50%owf), and time (30-90min). From a visual point of view, diverse eco-friendly shades with a rather diverse color gamut of varied hue and tone were generated by applying a wide range of natural and eco-label mordants. The impact of 4 bio-mordants (including peppermint, mugworts (Artemisia), Dorema ammoniacum (DA) gum, and pomegranate rind), as well as 4 mineral mordants (alum, copper (II) sulfate, potassium dichromate, and iron (II) sulfate) on the color and fastness properties of the dyed nylon samples, was assessed. The concentration of the used mordants was 5%owf, and the dyeing experiments were conducted by applying the pre-mordanting technique. Measurement of the color strength (K/S) of the dyed fabric was done using a reflectance spectrophotometer. The dyed nylon fastness qualities and the colorimetric characteristics were then evaluated by applying the related standards. The results showed that the optimum conditions for obtaining the highest color strength were dye concentration = 50%owf, pH = 6, temperature = 100°C, and dyeing tome = 60min. The proposed ISO standards in relation to colorfastness displayed acceptable ratings for the color strength of dragon's blood resin dyed fabric while its treatment was done by applying bio-mordants in comparison to its metallic counterparts. Therefore, dragon's blood resin could be regarded as a promising eco-friendly natural colorant source for the purpose of sustainable nylon dyeing.

Simultaneous nitrification and autotrophic denitrification in fluidized bed reactors using pyrite and elemental sulfur as electron donors

In this study, simultaneous nitrification and autotrophic denitrification (SNAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was evaluated at different ammonium (12–40 mg/L of NH4+-N), nitrate (35–45 mg/L of NO3−-N), and dissolved oxygen (DO) (0.1–1.5 mg/L) concentrations, with a hydraulic retention time of 12 h. The pyrite reactor supported the SNAD process with a maximum nitrogen removal efficiency of 139.5 mg/(L⸱d) when the DO concentration was in the range of 0.8–1.5 mg/L. This range, however, limited the denitrification efficiency of the reactor, which decreased from 90.0% ± 5.3% in phases II–V to 67.9% ± 7.2% in phases VI and VII. Sulfate precipitated as iron sulfate (FeSO4/Fe2(SO4)3) and sodium sulfate (Na2SO4) minerals during the experiment. The sulfur reactor did not respond well to nitrification with a low and unstable ammonium removal efficiency, while denitrification occurred with a nitrate removal efficiency of 97.8%. In the pyrite system, the nitrifying bacterium Nitrosomonas sp. was present, and its relative abundance increased from 0.1% to 1.1%, while the autotrophic denitrifying genera Terrimonas, Ferruginibacter, and Denitratimonas dominated the community. Thiobacillus, Sulfurovum, and Trichlorobacter were the most abundant genera in the sulfur reactor during the entire experiment.

Modified oyster shell powder with iron (II) sulfate heptahydrate to improve arsenic uptake in solution and in contaminated soils.

Arsenic is a metalloid whose presence can be due to natural or anthropological causes. It is considered as a toxic chemical that puts human health at high risk. In this study, we evaluated a novel modified oyster shell (MOS) that was coated with iron (II) sulfate heptahydrate using two different proportions through batch sorption experiments in an arsenic solution and in arsenic-contaminated soils. The arsenic solution was prepared using As(III)-standard solution. The arsenic contaminated soils were extracted from a contaminated site in Cheonan, South Korea, where the average arsenic concentration of the soil was reported as 136.28mg/kg. Different doses of oyster shell and modified oyster were used to understand the effect of the addition of iron (II) sulfate heptahydrate via sorption batch experiments in solution and sorption tests in soils. The sorption tests were conducted with 50g of contaminated soil; then, 150g of soils was used for the pot cultivation tests, and finally, 150g of contaminated soils was used for column percolation test. Through the experiments, the authors observed a comparable improvement of arsenic stabilization from 10 to 60% with the addition of iron (II) sulfate heptahydrate to oyster shell.

Sulfate-Decorated Amorphous–Crystalline Cobalt-Iron Oxide Nanosheets to Enhance O–O Coupling in the Oxygen Evolution Reaction

The electrochemical oxygen evolution reaction (OER) plays a fundamental role in several energy technologies, which performance and cost-effectiveness are in large part related to the used OER electrocatalyst. Herein, we detail the synthesis of cobalt-iron oxide nanosheets containing controlled amounts of well-anchored SO42- anionic groups (CoFexOy-SO4). We use a cobalt-based zeolitic imidazolate framework (ZIF-67) as the structural template and a cobalt source and Mohr's salt ((NH4)2Fe(SO4)2·6H2O) as the source of iron and sulfate. When combining the ZIF-67 with ammonium iron sulfate, the protons produced by the ammonium ion hydrolysis (NH4+ + H2O = NH3·H2O + H+) etch the ZIF-67, dissociating its polyhedron structure, and form porous assemblies of two-dimensional nanostructures through a diffusion-controlled process. At the same time, iron ions partially replace cobalt within the structure, and SO42- ions are anchored on the material surface by exchange with organic ligands. As a result, ultrathin CoFexOy-SO4 nanosheets are obtained. The proposed synthetic procedure enables controlling the amount of Fe and SO4 ions and analyzing the effect of each element on the electrocatalytic activity. The optimized CoFexOy-SO4 material displays outstanding OER activity with a 10 mA cm-2 overpotential of 268 mV, a Tafel slope of 46.5 mV dec-1, and excellent stability during 62 h. This excellent performance is correlated to the material's structural and chemical parameters. The assembled nanosheet structure is characterized by a large electrochemically active surface area, a high density of reaction sites, and fast electron transportation. Meanwhile, the introduction of iron increases the electrical conductivity of the catalysts and provides fast reaction sites with optimum bond energy and spin state for the adsorption of OER intermediates. The presence of sulfate ions at the catalyst surface modifies the electronic energy level of active sites, regulates the adsorption of intermediates to reduce the OER overpotential, and promotes the surface charge transfer, which accelerates the formation of oxygenated intermediates. Overall, the present work details the synthesis of a high-efficiency OER electrocatalyst and demonstrates the introduction of nonmetallic anionic groups as an excellent strategy to promote electrocatalytic activity in energy conversion technologies.

Optimizing iron seed priming for enhanced yield and biofortification of tomato

Iron (Fe) is an important micronutrient required for healthy life. Malnutrition resulting from low Fe in plant-based foods has caused serious problems worldwide. We propose that Fe biofortification of tomato through seed priming would be an innovative approach to address the problem Fe deficiency. This research was conducted to find the impact of Fe seed priming on germination, morphology, physiology, growth, yield, and final enrichment of Fe in fruit of tomato in two commercial hybrids. Tomato seeds were primed with different concentrations of iron sulfate heptahydrate (FeSO4.7H2O) in the range of 1–15 mg L−1, resulting in differential accumulation of tomato fruit Fe contents. We observed a marked improvement in tomato seedling traits, yield contributing traits, fruit quality, biochemical attributes and physiological parameters. Interestingly, the Fe treatment concentration of 10 mg L−1 demonstrated improved tomato growth with a significant increase in fruit Fe contents to of 2.04 and 2.37 which are very much higher as compared to control having Fe contents of 1.47 and 1.49 ppm respectively. Fe seed priming of tomato represents as a cost effective and user-friendly strategy for tomato biofortification which triggers Fe acquisition and its final enrichment in tomato fruit.

Effect of Iron Nutrition on Growth and Productivity of Aerobic Rice (Oryza sativa)

A field experiment was conducted during kharif seasons (June–October) of 2012 and 2013 at College Farm, College of Agriculture, Professor Jayashankar Telangana State Agricultural University, Hyderabad, Telengana, India to evaluate the response of rice cultivars and iron nutrition on growth and yield of aerobic rice. Experiment comprising of three rice cultivars (Tellahamsa, MTU 1010 and KRH 2) and twelve sources and modes of iron nutrition i.e. control (no iron), basal application of iron sulphate @ 25 kg ha-1, basal application of Iron chelate @ 25 kg ha-1, 3 foliar sprays of 2% iron sulphate @ 7 days interval, 3 foliar sprays of 2% iron sulphate @ 10 days interval and 3 foliar sprays of 2% iron sulphate @ 15 days interval. Next 3 treatments were three foliar sprays of 2% iron sulphate in conjunction with basal application of iron sulphate @ 25 kg ha-1. Subsequent treatments were three foliar sprays of 2% iron sulphate with basal combination of iron chelate @ 25 kg ha-1. Results indicated that among rice cultivars KRH 2 gave significantly better agronomic performance with respect to growth parameters and yield. Iron nutrition treatments significantly affected the plant height, tillers, dry matter accumulation and yield of aerobic rice. Basal application of iron chelate @ 25 kg ha-1 with 3 foliar sprays of iron sulphate at 7 days interval produced tallest plants, maximum number of tillers, accumulated highest dry matter and produced maximum yield during both the years.

Iron Sulfate (FeSO4) Improved Physiological Attributes and Antioxidant Capacity by Reducing Oxidative Stress of Oryza sativa L. Cultivars in Alkaline Soil

Rice ranks second among cereals in dietary uses around the world. Rice is deficient in iron (Fe), and these are important micronutrients for infants, men, and women. Fortification of rice with iron would help to minimize nutrient deficiency disorders among humans. The current study aims to introduce nutrient-rich rice. The effects of iron on germination, growth, photosynthetic pigment, antioxidant activity, and reduction of oxidative stress were investigated in four Oryza sativa L. cultivars. O. sativa of four different cultivars (Basmati-515, PK-386, KSK-133, and Basmati-198) were grown under five treatments (100, 200, 300, 400, and 500 mM) of iron sulphate (FeSO4) in soil of pH 7.5, along with control, by using six replicates. The result revealed that Fe treatment significantly affected seed germination percentage, plant growth parameters, biomass, photosynthetic pigments (chl a, chl b, total chlorophyll, and carotenoids), antioxidant enzymatic and non-enzymatic activity, and reduced oxidative stress. The findings also showed that Fe application reduced the oxidative stress including malondialdehyde content and hydrogen peroxide, by increasing the antioxidant enzymatic activity, i.e., catalase, ascorbate peroxidase, superoxide dismutase, peroxidase, glutathione peroxidase, 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), and non-enzymatic antioxidant compounds (proline, amino acid, total soluble protein, phenolics, flavonoids, reducing-non-reducing sugar, and carbohydrates) in all cultivars of O. sativa. Furthermore, FeSO4 induced a significant increase in proline, free amino acid, and total carbohydrates in the leaves of all O. sativa cultivars, but Basmati-198 showed the significantly highest content by 169, 88, and 110%, respectively, at concentration of 500 mM. The present research work showed that soil application of FeSO4 improved the seed germination, plant growth, and antioxidants enzymatic and non-enzymatic activity, denatured the ROS (reactive oxygen species) in alkaline soil. In order to understand the underlying mechanisms, long-term field investigations should be carried out at the molecular level to examine patterns of iron uptake and plant growth.

Investigation of Mordant Application in Reactive Dyeing of Nylon Fabrics

Nylon fibers were the first synthetic fibers to be produced on an industrial scale, and they are one of the most consumed synthetic fibers due to their visual and usage properties. Reactive dyes have been commercially produced since the mid-20th century, and they are mostly preferred in dyeing cellulosic fibers. The most important property of reactive dyes is their ability to make covalent bonds within the fiber. Mordants are used mainly in the application of natural dyes to hold and retain the dye molecules in the fiber. In this paper, nylon fabrics were dyed with three reactive dyes having different reactive groups (monochlorotiazine, trifluoropyrimidine and monochlorotriazine/vinylsulfone) in the presence of three chemical mordants (iron (II) sulfate, potassium aluminum sulfate and tannic acid) to obtain better exhaustion and coloration properties. Pre-mordanting, meta-mordanting, and post-mordanting processes were used for dyeing. The dyeings were performed at two dyeing concentrations (0.5% and 2% owf), and at three pH levels (pH 2, 4, and 6). The percentage of dyebath exhaustion (%E), the percentage fixation of the dye which exhausted (%F) and the overall percentage fixation (%T) were calculated after pyridine extraction. Wash and light fastness tests were applied on the dyed samples. The results were discussed via % E, % T and CIELAB color differences (Δ Eab*). The results revealed that mordant usage improved the coloration properties of reactive dyes on nylon fabrics. The % E and % T results changed according to the independent variations of pH level, mordant chemical and mordanting method. The correct pH level and mordanting method gave the best dyeing and fastness results for the dyes under test.

Activation of sulfite by FeS for anaerobic fermentation enhancement of waste activated sludge: Performance and mechanisms

Maximizing resource recovery by improving the anaerobic treatment efficiency of waste activated sludge (WAS) is critical to reducing carbon emissions. In this study, a concept of “co-treating” WAS with sulfite-laden wastes (sulfite) and mackinawite (FeS) was proposed to improve the anaerobic fermentation performance of WAS. Experimental results showed that the maximal short-chain fatty acids (SCFAs) yield of 2461.4 mg COD/L and corresponding acetate proportion (55.9 %) were obtained with a sulfite/FeS ratio of 0.8 at 500 mg S/L sulfite. It was found that •OH, SO4•-,.O2, and 1O2 free radicals produced by FeS/sulfite pretreatment could decompose the sludge flocs significantly, resulting in reduced particle size and viable cell ratio, thereby providing more available organics for SCFAs production. Mechanism investigations revealed that FeS/sulfite pretreatment enhanced the production of SCFAs by increasing key hydrolytic enzymes, improving the abundance of microorganisms related to hydrolysis and acidification and altering the functional traits of the corresponding microbes. FeS/sulfite pretreatment also facilitated the conversion of propionate and butyrate acid to acetate during anaerobic fermentation, probably due to FeS/sulfite-induced iron reduction and sulfate reduction. The GC–MS results suggested that FeS/sulfite pretreatment promoted the quality of the fermentation mixture by decreasing the refractory compounds. This work provided a practical approach to the final disposal of WAS with added economic and environmental value.

Iron doses on growth and gas exchange of dwarf cashew seedlings

Cashew plants have shown, a few days after planting in the field, interveinal chlorosis in young leaves and, as the symptoms become worse, the leaves are completely chlorotic, a nutritional disorder that is related to iron (Fe) deficiency. Thus, the objective was to evaluate the growth and physiological responses of grafted seedlings of dwarf cashew as a function of Fe doses. The experiment was conducted in a greenhouse, in a completely randomized design, with four replicates. Treatments consisted of five doses of Fe (0; 2.5; 5; 7.5 and 10 mg L−1), using iron sulfate (20% Fe) as source. The following parameters were evaluated: growth variables – height, number of leaves, leaf area, stem diameter and dry matter (roots, shoots and total); and physiological variables – photosynthesis (A), stomatal conductance (gs), transpiration (E), water use efficiency (WUE), instantaneous carboxylation efficiency (A/Ci), photosynthetic pigments and relative chlorophyll index. Fe deficiency affected the photosynthetic process, causing significant reductions in the evaluated characteristics, indicating the need for its adequate supply for the growth of dwarf cashew plants.

Approaches for filtrate utilization from synthetic gypsum production.

Waste recycling and industrial wastewater treatment have always been of interest. A green approach was developed for the filtrate of synthetic gypsum production from water treatment coagulation sediments and spent sulfuric acid. Due to the high concentration of iron sulfate, concentrated filtrate showed good coagulation results, which were 5% lower than pure iron sulfate. In addition, a high concentration of iron facilitates its use as a precursor for synthesizing magnetic sorbents and photocatalysts. Such materials were synthesized by the solution combustion synthesis method. Oil sorption capacity reached 1.8g/g, comparable to some synthetic materials and higher than sorption materials based on natural materials. Photodegradation of acid telon blue dye after 90min of irradiation time was 82.7% with catalyst derived from filtrate compared to the just dye solution with 17.6% efficiency. The reaction rate constant for the photocatalyst sample was up to 11.4-fold higher compared with only UV treatment. The neutralized filtrate containing sulfur, calcium, magnesium, and sodium has been tested as a complex fertilizer. The results of bioindication for oil radish showed up to a 15% increase in the shoot length. A number of techno-economic indicators show that such an approach is advantageous from a technological, environmental, and economic point of view.

Pyrolytic synthesis of graphene-encapsulated zero-valent iron nanoparticles supported on biochar for heavy metal removal

Biochar (BC)-supported graphene-encapsulated zero-valent iron nanoparticle composites (BC-G@Fe0) are promising engineering nanocomposites that can be used to scavenge heavy metal from wastewater. However, the production of BC-G@Fe0 through carbothermal reduction using biomass as a carbon source remains challenging because of biomass pyrolysis complications. Here, we examined two carbothermal reduction routes for preparing BC-G@Fe0 using bamboo as the carbon source. The first route impregnated Fe ions (Fe2+/3+) into unpyrolyzed bamboo particles initially, followed by carbonization at 600–1000 °C. This process produced BC-G@Fe0 dominated by iron carbide (Fe3C), which led to low heavy metal removal efficiency (i.e., Cu2+ capacity of < 0.3 mmol g−1). In the second route, bamboo particles were pyrolyzed (600 °C) to biochar first, followed by impregnating this biochar with Fe ions, and then carbonized at 600–1000 °C. This route produces zero-valent iron nanoparticles, which resulted in high heavy metal removal capacities (i.e., 0.30, 1.58, and 1.91 mmol g−1 for Pb2+, Cu2+, and Ag+, respectively). The effects of carbonization temperature (600–1000 °C), iron source (i.e., iron nitrates, iron sulfate, ferrous chloride, and ferric chloride), and iron loading (5–40%) on the morphology, structure, and heavy metal ion aqueous uptake performance of BC-G@Fe0 were also investigated. This study revealed the formation mechanisms of BC-G@Fe0 through biomass carbothermal reduction, which could guide the application-oriented design of multifunctional iron-BC composites for water remediation.Graphical

Phenotypic differences between Edwardsiella piscicida and Edwardsiella anguillarum isolates in Japan.

Most studies refer to Edwardsiella tarda as the causative agent of edwardsiellosis in the cultured marine and freshwater fish species in Japan; however, our previous study was the first to genetically classify an E. tarda-like isolate from diseased olive flounder as E. piscicida and that from diseased red sea bream as E. anguillarum. This study aimed to understand the phenotypical differences between the two species. The API 50 CH test showed that L-arabinose and D-mannitol were fermented by 7 E. anguillarum isolates, but not by 14 E. piscicida isolates; the difference is likely to be useful for the recognition of E. piscicida, although it was not common among previously-reported E. anguillarum isolates. The use of the defined medium consisting of M9 minimal medium supplemented with 43 components revealed that the growth of E. piscicida and E. anguillarum was reduced in the defined medium without methionine and iron sulfate. Individually, the growth of E. piscicida was reduced in the defined medium without phenylalanine, tyrosine, alanine, or nicotinic acid, whereas the growth of E. anguillarum was reduced without serine, cysteine, leucine, threonine, or isoleucine. Tyrosine and alanine were present in higher concentrations in the olive flounder serum and threonine and isoleucine were present in higher concentrations in the red sea bream serum, compared with each other, suggesting that E. piscicida and E. anguillarum may have the advantage of growth opportunity in their hosts. Finally, the minimal defined medium for the two species was determined to enable safe vaccine development.