Iron Sulfate Research Articles

Investigation of the dehydration process of iron(II) sulfate heptahydrate by filtration method

The filtration method of dehydrating iron(II) sulfate heptahydrate was proposed to involve the formed compounds in the production process of fabrication of iron oxide pigments. Using the method of complex thermal analysis, the influence of the heating rate on the temperature limits and the intensity of the dehydration process was revealed. Based on the results of the differential thermal analysis, the heat agent temperature was chosen to be 3350.5 K, which is lower than the melting point of the sample. The effects of increasing the speed of the heat agent on the kinetics of dehydration of iron(II) sulfate heptahydrate by the filtration method and on the intensity of the heat exchange process were determined. The values of the heat transfer coefficients were calculated based on experimental data in a thin layer and from the calculated dependence. The calculated coefficients were generalized using a dimensionless dependence within the range of Reynolds numbers of 20 to 100. The equation for forecasting heat energy costs at the stage of designing equipment for dehydration was proposed.

Effect of Post Emergence Herbicidal Combinations Tank Mixed with Zinc or/and Iron Sulphate on Growth and Straw Yield of Wheat Crop ( L.)

Effect of Post Emergence Herbicidal Combinations Tank Mixed with Zinc or/and Iron Sulphate on Growth and Straw Yield of Wheat Crop ( L.)

New Insights for Improving Agriculture Soils through Nanotechnology

Different efforts have been made especially in the fields of nanotechnology that employed various combinations of nanoparticles to overcome the stresses occurred in the agricultural lands. Nanoparticles that potentially designed through nanotechnology applied to the soil in the form nanofertilizers that increased the yield also good impact on soil composition. Application of nano-SiO2 improves also seed germination throiugh rooting applications, chlorophyll content with proline accumulation. Soil composition also improved the overall fruits and vegetables varieties in such a way that nanoparticles makes intact combinations with inner layers of soil. Biological applications of iron sulfate (FeSO4) in the form of foliar spray also showed excellent resistance to the salinity stress tolerance in the case of sunflower cultivars. Nano zeolite; another type of newly modified materials efficient for long term delivery of nutrients and minerals in soil composition and mineral balance ensures for plant growth. Nanopesticides can be used for efficient crop protection also promote plant stress tolerance and soil enhancement. Nano-Si that improves the various other stresses in plants species such as nickle and chromium. Nanotechnology has several advantages over other technologies due to cost efficient and simple to use and imply on more effective treatment and remediation methods.

Effect of the Precursor and Synthesis Mode on the Properties of Hematite for the Preparation of Promoted Iron Oxide Catalysts

The fine crystal structure of hematite samples used to prepare potassium-promoted iron oxide dehydrogenation catalysts has been studied by X-ray diffraction and scanning electron microscopy. Samples of α-Fe2O3 were obtained under nonequilibrium conditions from several precursors under different thermolysis regimes. The most important characteristic of hematite, which determines the activity and selectivity of the catalyst based on it, is the fine crystal structure (TCS). The TCS of hematite determines the phase composition of the catalyst. The TCS of hematite is formed during the synthesis of hematite and is determined by the nature of the precursor, the temperature of sample synthesis, and the temperature gradient of the rate of removal of gaseous thermolysis products. The highest activity was demonstrated by a catalyst prepared on the basis of hematite with mosaic blocks of 70–90 nm, with a minimum concentration of SF due to half and quaternary dislocations. Such hematite was obtained by thermolysis of iron sulfate at 950 K under fluidized bed conditions and a low temperature gradient. Hematite from iron carbonate is not recommended for the synthesis of a catalyst due to the high concentration of low-temperature SF, which leads to the formation of catalytically inactive potassium β-polyferrite.

Trace Element Interactions, Inflammatory Signaling, and Male Sex Implicated in Reduced Growth Following Excess Oral Iron Supplementation in Pre-Weanling Rats.

Iron supplements are frequently provided to infants in high-income countries despite low incidence of iron deficiency. There is growing concern regarding adverse health and development outcomes of excess iron provision in early life. Excess iron may directly damage developing organs through the formation of reactive oxygen species, alter systemic inflammatory signaling, and/or dysregulate trace mineral metabolism. To better characterize the in vivo effects of excess iron on development, we utilized a pre-weanling rat pup model. Lewis rat litters were culled to eight pups (four males and four females) and randomly assigned to daily supplementation groups receiving either vehicle control (CON; 10% w/v sucrose solution) or ferrous sulfate (FS) iron at one of the following doses: 10, 30, or 90 mg iron/kg body weight—FS-10, FS-30, and FS-90, respectively—from postnatal day (PD) 2 through 9. FS-90 litters, but not FS-30 or FS-10, failed to thrive compared to CON litters and had smaller brains on PD 10. Among the groups, FS-90 liver iron levels were highest, as were white blood cell counts. Compared to CON, circulating MCP-1 and liver zinc were increased in FS-90 pups, whereas liver copper was decreased. Growth defects due to excess FS provision in pre-weanling rats may be related to liver injury, inflammation, and altered trace mineral metabolism.

Performance of Iron(II)-Sulphate-Treated Norway Spruce and Siberian Larch in Laboratory and Outdoor Tests

Wood in outdoor applications is exposed to various environmental factors that cause weathering. Weathering is important, primarily from an aesthetic standpoint and predominantly in wooden claddings. However, not all parts of claddings are equally exposed to weathering. Sections exposed to UV radiation and moisture discolour faster than less exposed sections, such as wood under roof overhangs. Architects and owners seek a uniform appearance in buildings. To achieve fast and uniform greying, a surface treatment with iron(II) sulphate can be used. Such a treatment results in an appearance that is similar to that resulting from natural greying. However, iron compounds do not exert a biocidal effect; therefore, it is desirable to upgrade iron(II) sulphate aqueous solution with boric acid and quarterly ammonium compounds. To this end, spruce and larch samples were treated with varying concentrations of iron(II) sulphate and biocides. After treatment, the inherent durability, water performance and resistance dose (DRd) were determined according to the Meyer-Veltrup model. The samples were also exposed outdoor conditions. During exposure, colour changes and iron leaching were monitored. The results show that the addition of biocides does not affect the rate of colour change and the final colour, which is similar to natural greying after 36 weeks of outdoor exposure. The addition of biocides exerted a positive effect on the durability of treated wood, despite the low retention of preservative solutions. The water behaviour of the treated wood had little effect on the resistance dose, with a more considerable influence on inherent durability. The addition of biocides can increase the resistance dose up to 2.4 (Fe5B0.2Q0.2). On all spruce and larch samples treated with iron(II) sulphate and exposed to outdoor conditions, the colour change in the first week was roughly comparable to the final state. However, 40% of the iron had leached from the surface after only one week of exposure.

On the Cobalt Content Upgrade in Nickeliferous Laterites Using Iron (III) Sulfate: A Study Based on Thermodynamics Simulations

Nickel (Ni) and cobalt (Co) are relevant technological metals for the future of the lithium-ion battery (LIB) industry. Based on the current and projected demand for these, an increased interest in developing processing routes to exploit lateritic occurrences has been observed, as these are reported as critical raw materials for future mineral–metallurgical industry. However, the content of Ni and Co in such ores is minimal and requires impracticable mineral-processing operations for concentration before metal extraction. It was identified that information regarding the sulfation roasting of this material is scarce on what concerns the iron sulfates interaction as a function of the temperature. Based on that context, the present work has its purposes associated with the proposition of an alternative chemical pretreatment to upgrade the content of metals of technological interest in lateritic ores through a simple roast–leach process. Thus, the chemical interactions between the mineral sample and iron (III) sulfate (Fe2(SO4)3) through thermodynamic simulations and experimental procedures were explored. The latter included specific water leaching practices for the selective concentration of metals. The equilibrium calculations indicate that Fe2(SO4)3 and FeSO4 tend to decompose at lower temperatures, and considering the higher stability of other metal sulfates, it could be an interesting reagent in this type of process. Regarding the experimental results, the characterization of materials indicates a recovery of Co as high as 73.4 wt.% after sulfation roasting at 500 °C followed by water leaching, with the full content of Iron (Fe) being reported in the insoluble phase. Based on these findings, the present development could be an interesting alternative to consider within operations for the chemical upgrade of cobalt in such types of mineralogical occurrences.

Composition Characteristics and Construction Mechanism of Microbial Community on Microplastic Surface in Typical Redox Environments

Microplastics are widely distributed in the biogeochemical cycle driven by microbes. Their surface is enriched with unique microbial communities, called plastispheres. Various redox environments that exist widely in the natural environment can affect the microbial composition in the plastisphere and the fate of the microplastics. To explore the microbial community composition and construction mechanism on the surface of microplastics in typical redox environments, three microplastics, PHA (polyhydroxyalkanoates), PLA (polylactic acid), and PVC (polyvinyl chloride), were placed in five specific redox environments:aerobic, nitrate reduction, iron oxide reduction, sulfate reduction, and methane production. The culture experiment simulated the microcosm, which was inoculum by sludge. The results showed that microplastic factors affected 18.94% and 46.67% of the microbial communities on the plastisphere in taxonomy and phylogeny, respectively. Redox factors affected 31.04% and 90.00% of the microbial communities on the plastisphere in taxonomy and phylogeny, respectively. Compared with that in sludge, the microbial community richness and diversity were reduced on the three microplastics. The most apparent reduction was found on the plastisphere of more degradable PHA. At the same time, microbial communities on the refractory PLA and PVC surfaces remained similar. Anaerocolumna (26.44%) was the dominant genus on the surface of PHA microplastics, whereas microbes related to the redox reaction were less enriched. Clostridium_sensu_stricto_7 (15.49% and 11.87%) was the dominant strain on PLA and PVC microplastics, and the microbes related to the redox reaction were significantly enriched. Thus, characteristic microbes involved in the redox reaction will be enriched in the surface of refractory microplastics, and microplastics may affect the rate of biogeochemical cycling.

Iron sulfate and molasses treated anthocyanin-rich black cane silage improves growth performance, rumen fermentation, antioxidant status, and meat tenderness in goats.

This study investigated the effects of feeding anthocyanin-rich black cane treated with ferrous sulfate and molasses on animal performance, rumen fermentation, microbial composition, blood biochemical indices, and carcass characteristics in meat goats. Thirty-two Thai-native×Anglo-Nubian crossbred male goats (14.47±2.3 kg) were divided equally into two groups (n = 16) to investigate the effect of feeding diet containing 50% untreated anthocyanin-rich black cane silage (BS) vs diet containing anthocyaninrich black cane silage treated with 0.03% ferrous sulfate and 4% molasses (TBS) on average daily gain (ADG) and dry matter intake (DMI). At the end of 90 d feeding trial, the goats were slaughtered to determine blood biochemical indices, rumen fermentation, microbial composition, and carcass characteristics differences between the two dietary groups. Goats fed the TBS diet had greater ADG and ADG to DMI ratio (p<0.05). TBS diet did not affect rumen fluid pH; however, goats in the TBS group had lower rumen ammonia N levels (p<0.05) and higher total volatile fatty acid concentrations (p<0.05). Goats in the TBS group had a higher (p<0.05) concentration of Ruminococcus albus but a lower (p<0.05) concentration of methanogenic bacteria. The TBS diet also resulted in lower (p<0.05) thiobarbituric acid-reactive substances concentration but higher (p<0.05) total antioxidant capacity, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase concentrations in blood plasma, while having no effect on plasma protein, glucose, lipid, immunoglobin G, alanine transaminase, and aspartate aminotransferase. Meat from goats fed the TBS diet contained more intramuscular fat (p<0.05) and was more tender (p<0.05). In comparison to goats fed a diet containing 50% untreated anthocyanin-rich black cane silage, feeding a diet containing 50% anthocyanin-rich black cane silage treated with 0.03% ferrous sulfate and 4% molasses improved rumen fermentation and reduced oxidative stress, resulting in higher growth and more tender meat.

Regulation of Iron-Ion Transporter SLC11A2 by Three Identical miRNAs.

Here, we searched for microRNAs (miRNAs) in silico that could interact with SLC11A2 mRNA, a solute carrier (SLC) iron-ion transporter, and investigated their effects on SLC11A2 gene expression using the cultured human colon carcinoma cell line, Caco-2. In silico analysis using the miRWalk2.0 database revealed that several types of miRNAs interact with the human SLC11A2 gene; we focused on three miRNAs, miR-149-5p, miR-362-5p, and miR-539-5p as candidates in this study. We first revealed that the three miRNAs interact with the SLC11A2 3'-untranslated region (3'-UTR) using a luciferase assay in a Caco-2 cell line. We then examined whether the expression of each miRNA affected the expression of SLC11A2 mRNAs and their transcribed transporter proteins. We found transiently expressed miRNAs significantly reduced the reporter activity of the SLC11A2 3'-UTR site in Caco-2 cells by significantly decreasing the SLC11A2 gene and protein expression in the miRNA-transfected Caco-2 cells. Subsequently, we investigated the effects of these miRNAs on SLC11A2's iron-ion transporting activity by measuring iron-ion concentration in Caco-2 cells. Administration of ammonium iron (II) sulfate hexahydrate to Caco-2 cells significantly increased the intracellular iron-ion concentration. However, in iron-ion-pretreated cells, overexpression of each of the three miRNAs resulted in decreased intracellular iron-ion concentration. This indicated that overexpressed miRNAs inhibited iron-ion influx into Caco-2 cells by attenuating SLC11A2 transporting activity. Using in silico analysis, we predicted that three studied miRNAs could bind to the iron-ion influx transporter SLC11A2 and revealed that they regulate SLC11A2 gene expression and iron-ion transporting function in an in vitro system.

Feasibility of direct conversion of copper present in waste printed circuit boards to oxidation-resistant materials employing eco-benign iron(III) sulfate and ascorbic acid

This study presents the feasibility of an eco-benign, practical hydrometallurgical process for the recovery of Cu(0) as an oxidation-resistant material from waste printed circuit boards (WPCBs) with minimum chemical consumption. In leaching, metals were leached using Fe2(SO4)3, and 98.4 ± 1.5% Cu(II) was achieved under optimum conditions (0.1 M Fe2(SO4)3, 10 g/L pulp density, 25 °C, and 6 h). Then, 95.8 ± 0.3% Cu(0) was selectively recovered from multi-metal containing acidic leachate by a cementation method under the optimum conditions (0.3 M ascorbic acid, 70 °C, and 4 h). The as-recovered Cu(0) was characterized via quantitative and qualitative analyses and compared with a commercial Cu(0) as a reference material. As results, the high purity Cu(0) (99.2% Cu and 0.44% Ag) was recovered, and it was confirmed that the as-recovered Cu(0) can be used as an oxidation-resistant material owing to a trace amount of Ag. Finally, the economic feasibility of the developed process was evaluated based on the experimental results and the price of oxidation-resistant Cu in the e-commerce market ($10–50/kg). The minimum selling price of as-recovered Cu(0) can be estimated to be $26.16 per kg, which is a reasonable market price for oxidation-resistant Cu(0).

Production of microalgal-based carbon encapsulated iron nanoparticles (ME-nFe) to remove heavy metals in wastewater

The integration of microalgae-bacteria consortia within existing wastewater treatment plants as alternative biological treatment could be an interesting option to improve the sustainability of these facilities. However, the fate of the produced biomass is decisive to make that option economically attractive. The present study aimed to valorize the microalgae grown at a pilot scale and used for the treatment of the centrate from municipal sewage sludge, producing microalgal-based iron nanoparticles (ME-nFe), by hydrothermal carbonization. The final product had high carbon content, strong sorbent power, and reducing properties, due to the presence of zerovalent iron. Different synthesis conditions were tested, comparing iron (III) nitrate nonahydrate (Fe (NO3)3·9H2O) and ammonium iron (III) sulfate dodecahydrate (NH4 Fe (SO4)2·12 H2O) as iron sources, four different Fe/C molar ratios (0.02, 0.05, 0.1, 0.2), and three process temperatures (180, 200, 225 °C). Based on the characterization of all the prototypes, the best one (having a specific area of 110 m2g−1) was chosen and tested for the removal of selected heavy metals by Jar tests. The removal of copper, zinc, cadmium, and nickel from the treated effluent from the wastewater treatment plant was 99.6%, 97.8%, 96.4%, and 80.3%, respectively, also for very low starting concentrations (1 mg L−1). The removal of total chromium, on the contrary, was only 12.4%. Thanks to the magnetic properties, the same batch of ME-nFe was recovered and used effectively for three consecutive Jar tests.

Weak Coordinating Character of Organosulfonates in Oriented Silica Films: An Efficient Approach for Immobilizing Cationic Metal-Transition Complexes.

Iron (II) tris(2,2′-bipyridine) complexes, [Fe(bpy)3]2+, have been synthesized and immobilized in organosulfonate-functionalized nanostructured silica thin films taking advantage of the stabilization of [Fe(H2O)6]2+ species by hydrogen bonds to the anionic sulfonate moieties grafted to the silica nanopores. In a first step, thiol-based silica films have been electrochemically generated on indium tin oxide (ITO) substrates by co-condensation of 3-mercaptopropyltrimethoxysilane (MPTMS) and tetraethoxysilane (TEOS). Secondly, the thiol function has been modified to sulfonate by chemical oxidation using hydrogen peroxide in acidic medium as an oxidizing agent. The immobilization of [Fe(bpy)3]2+ complexes has been performed in situ in two consecutive steps: (i) impregnation of the sulfonate functionalized silica films in an aqueous solution of iron (II) sulfate heptahydrate; (ii) dipping of the iron-containing mesostructures in a solution of bipyridine ligands in acetonitrile. The in situ formation of the [Fe(bpy)3]2+ complex is evidenced by its characteristic optical absorption spectrum, and elemental composition analysis using X-ray photoelectron spectroscopy. The measured optical and electrochemical properties of immobilized [Fe(bpy)3]2+ complexes are not altered by confinement in the nanostructured silica thin film.

Evaluation of removal of acid dyes using PAM-FeSO4 hybrid polymer as flocculant

PurposeIn this study, the removal of a series of acid dyes by hybrid polymer adsorbent was investigated. Textile industry wastewater is mainly consisted of suspended solid particles and organic compounds with complex and nondecomposable structures. Treatment of such wastewaters has received much attention by researchers because of high water consumption and the presence of various chemical compounds, especially dyes. The use of polymers has recently attracted much attention for the treatment of textile wastewaters. According to the literature, hybrid polymers are highly capable of adsorbing dyes. In this research work, polyacrylamide/iron sulfate (PAM-FeSO4) hybrid polymer was successfully synthesized through solution polymerization of acrylamide with ammonium persulfate and sodium thiosulfate and gradual addition of iron sulfate. The hybrid polymeric adsorbent was then used for removing acidic dyes with different chemical structures.Design/methodology/approachThe effects of various experimental conditions and parameters, such as initial concentrations of dye and adsorbent, on the adsorption capacity of the adsorbent were investigated. The dye concentration was measured by an UV–vis spectrophotometer. The adsorption equilibrium was studied by plotting adsorption isotherms. The experimental data was fitted to Langmuir and Freundlich isotherms.FindingsThe adsorption experiments indicated that the PAM-FeSO4 hybrid polymer has a high adsorption capacity (117.64 mg g−1 for the Orange ІІ and 80.64 mg g−1 for the Sunset Yellow [SY]) when 80 mg of adsorbent was immersed in the dye solution (1 g L−1) with a pH of 11 at 25°C. The analysis of the equilibrium isotherms using the Langmuir and Freundlich isotherms indicated that the Langmuir model fit well to the experimental data.Originality/valueTo the best of the authors’ knowledge, this study is original. The removal of acid dyes such as Sunset Yellow and Methyl Orange using PAM-FeSO4 hybrid polymer as flocculant was done for the first time.

Iron cellular uptake from almond and coconut beverages using an in vitro intestinal cell model

Plant-based beverages could contain iron but also phenolic compounds (PC) and ascorbic acid, which are considered modulators of iron uptake. We investigated whether iron from almond and coconut beverages can be taken up by Caco-2 cells. The iron content in almond and coconut beverages was 19.20 and 19.34 mg kg−1 dry weight (dw), respectively; PC were 727.71 and 673.11 mg gallic acid equivalents kg−1, respectively; and ascorbic acid 10.96 mg kg−1 and 24.44 mg∙kg−1, respectively. We observed an increase in iron uptake by induction of cellular ferritin at concentrations of 15 and 30 g L−1 (almond) and 30 g L−1 (coconut). Both beverages significantly increased ferritin induction when iron sulfate was added. Thus, these beverages represent iron sources which can either contribute directly to iron supply or indirectly by enhancing absorption of exogenous iron and contribute to decrease the impact of diseases considered public health problems.

Understanding redox processes during iron precipitation in standing water: implications in formation of iron oxides minerals in the terrestrial planetary environment (especially Mars)

Iron oxide minerals are found associated with sulfate rocks in Meridiani Planum, Mars and in Valles Marineris, Mars. Similar occurrence of iron oxide minerals, hematite and sulfate rock is found on Earth. Many experiments are performed over the time to understand formation of iron oxide minerals and genetic link between iron oxide mineral and associated sulfate rock. Here also, an iron precipitation experiment is performed in presence of various secondary minerals. In the present experiment, the iron precipitation in the gypsum and siderite vessels occurs in increasing acidic and oxidizing conditions. And, the iron precipitation in the calcite and magnesite vessels occurs in increasing alkaline and reducing conditions. The reactions occurring between ammonium ferrous sulfate and various sulfate, carbonate minerals in separate vessels lead to iron speciation. This is evident from Eh–pH diagrams plotted for various minerals experimental vessels. Reddish-brown precipitate present in various experimental vessels suggests ferric iron precipitation and the greenish color precipitate suggests reduced ferrous iron in the system. XRD studies of the precipitated material indicate the formation of iron oxides mineral, goethite from the oxidation of ammonium ferrous sulfate compound in all experimental vessels except experimental vessels 3 and 4 (calcite + mohr’s salt ± charcoal), which have another iron oxides mineral, magnetite. The present research studies support the martian hematite formation model based on iron oxide mineral precipitation in standing water.

Iron Source and Medium pH Affect Nutrient Uptake and Pigment Content in Petunia hybrida 'Madness Red' Cultured In Vitro.

Deficiency or excess of iron (Fe) and improper medium pH will inhibit the growth and development of plants, reduce the transfer and utilization of energy from the root to the leaf, and affect the utilization efficiency of inorganic nutrients. The most common symptom of Fe deficiency in plants is chlorosis of the young leaves. In this study, the effects of the iron source, in combination with the medium pH, on plant growth and development, plant pigment synthesis, and nutrient uptake in a model plant Petunia hybrida cultured in vitro were investigated. Iron sulfate (FeSO4·7H2O) or iron chelated with ethylenediaminetetraacetic acid (Fe-EDTA) were supplemented to the MNS (a multipurpose nutrient solution) medium at a concentration of 2.78 mg·L−1 Fe, and the treatment without any Fe was used as the control. The pH of the agar-solidified medium was adjusted to either 4.70, 5.70, or 6.70 before autoclaving. The experiment was carried out in an environmentally controlled culture room with a temperature of 24 °C with 100 µmol·m−2·s−1 photosynthetic photon flux density (PPFD) supplied by white light emitting diodes (LEDs) during a photoperiod of 16 h a day, 18 °C for 8 h a day in the dark, and 70% relative humidity. Regardless of the Fe source including the control, the greatest number of leaves was observed at pH 4.70. However, the greatest lengths of the leaf and root were observed in the treatment with Fe-EDTA combined with pH 5.70. The contents of the chlorophyll, carotenoid, and anthocyanin decreased with increasing medium pH, and contents of these plant pigments were positively correlated with the leaf color. The highest soluble protein content and activities of APX and CAT were observed in the Fe-EDTA under pH 5.70. However, the GPX activity was the highest in the control under pH 4.70. In addition, the highest contents of ammonium (NH4+) and nitrate (NO3−) were measured in the FeSO4-4.7 and EDTA-5.7, respectively. More than that, the treatment of Fe-EDTA combined with pH 5.70 (EDTA-5.7) enhanced nutrient absorption, as proven by the highest tissue contents of P, K, Ca, Mg, Fe, and Mn. The genes’ ferric reduction oxidase 1 and 8 (PhFRO1 and PhFRO8), iron-regulated transporter 1 (PhIRT1), nitrate transporter 2.5 (PhNRT2.5), and deoxyhypusine synthase (PhDHS) were expressed at the highest levels in this treatment as well. In the treatment of EDTA-5.7, the reduction and transport of chelated iron in P. hybrida leaves were enhanced, which also affected the transport of nitrate and catalyzed chlorophyll level in leaves. In conclusion, when the medium pH was adjusted to 5.70, supplementation of chelated Fe-EDTA was more conducive to promoting the growth and development of, and absorption of mineral nutrients by, the plant and the expression of related genes in the leaves.

Mechanistic effect of SO2 on mesoporous CuFeAlZrOx catalyst for simultaneous removal of Hg0 and NO at wide temperature range

Mesoporous CuFeAlZrOx catalyst is a promising substitute of V-based catalysts for potential candidate for simultaneous removal of Hg0 and NO due to its excellent performance at a broad temperature range. SO2 poisoning effects remain a challenge in development of efficient SCR catalysts for applications. In this paper, the effect of SO2 on mesoporous CuFeAlZrOx catalyst for simultaneous removal of Hg0 and NO at wide temperature range was studied. Relevant characterization techniques of H2-TPR, NH3-TPD, TG, SO2-TPD, XPS, Hg-TPD and in situ DRIFTS were used to reveal the correlativity between the physicochemical properties and SO2 resistance of CuFeAlZrOx catalysts. SO2 exhibited an inhibitory effect at low temperature (<300 °C) but a facilitative effect at high temperature(≥300 °C) for NH3-SCR reaction. At the same time, a promoting effect on Hg0 removal was observed during the whole temperature range. The deposition of NH4HSO4 and the decrease of redox capacity caused the loss of SCR activity at low temperatures, while the formed iron sulfate provided more Lewis acid sites facilitate the high-temperature SCR performance due to the strong electron withdrawing effect of the SO double bonds. In addition, the generation of iron sulfates and NH4HSO4 on mesoporous Cu1FeAlZrOx were alleviated because of the sacrifice of copper sites and promoted NH4HSO4 decomposition in mesopore channels. SO2 reacted with Hg0 to form HgSO4 and Hg2SO4, which contributed to Hg0 removal performance.

Degradation of C. I. Direct Red 80 by the Electro-Fenton Process

Electro-Fenton process was applied in the degradation of the textile dye C. I. Direct Red 80 (DR80), using a boron-doped diamond anode and a carbon-felt cathode. The influence of the applied current density and of the type of iron source was evaluated. The iron sources studied were iron sulfate, ferric chloride, iron oxide and chalcopyrite, a natural iron-containing mineral. The obtained results showed that the electro-Fenton process is effective in the DR80 degradation and in the pollutant load elimination. Higher treatment efficiencies were attained when using iron sulfate as iron source. Still, the results obtained with the natural mineral chalcopyrite were quite promising. Although DR80 removal was more efficient at lower applied current densities, the same was not observed for the chemical oxygen demand removal, indicating that, at lower applied current densities, the dye is not completely mineralized, but rather transformed into other by-products.&#x0D; Keywords: C. I. Direct Red 80; Advanced oxidation processes; Electro-Fenton, Borondoped diamond anode, Carbon-felt cathode.

The root zone of graminoids: A niche for H2-consuming acetogens in a minerotrophic peatland.

The importance of acetogens for H2 turnover and overall anaerobic degradation in peatlands remains elusive. In the well-studied minerotrophic peatland fen Schlöppnerbrunnen, H2-consuming acetogens are conceptualized to be largely outcompeted by iron reducers, sulfate reducers, and hydrogenotrophic methanogens in bulk peat soil. However, in root zones of graminoids, fermenters thriving on rhizodeposits and root litter might temporarily provide sufficient H2 for acetogens. In the present study, root-free peat soils from around the roots of Molinia caerulea and Carex rostrata (i.e., two graminoids common in fen Schlöpnnerbrunnen) were anoxically incubated with or without supplemental H2 to simulate conditions of high and low H2 availability in the fen. In unsupplemented soil treatments, H2 concentrations were largely below the detection limit (∼10 ppmV) and possibly too low for acetogens and methanogens, an assumption supported by the finding that neither acetate nor methane substantially accumulated. In the presence of supplemental H2, acetate accumulation exceeded CH4 accumulation in Molinia soil whereas acetate and methane accumulated equally in Carex soil. However, reductant recoveries indicated that initially, additional unknown processes were involved either in H2 consumption or the consumption of acetate produced by H2-consuming acetogens. 16S rRNA and 16S rRNA gene analyses revealed that potential acetogens (Clostridium, Holophagaceae), methanogens (Methanocellales, Methanobacterium), iron reducers (Geobacter), and physiologically uncharacterized phylotypes (Acidobacteria, Actinobacteria, Bacteroidetes) were stimulated by supplemental H2 in soil treatments. Phylotypes closely related to clostridial acetogens were also active in soil-free Molinia and Carex root treatments with or without supplemental H2. Due to pronounced fermentation activities, H2 consumption was less obvious in root treatments, and acetogens likely thrived on root organic carbon and fermentation products (e.g., ethanol) in addition to H2. Collectively, the data highlighted that in fen Schlöppnerbrunnen, acetogens are associated to graminoid roots and inhabit the peat soil around the roots, where they have to compete for H2 with methanogens and iron reducers. Furthermore, the study underscored that the metabolically flexible acetogens do not rely on H2, potentially a key advantage over other H2 consumers under the highly dynamic conditions characteristic for the root-zones of graminoids in peatlands.