Papers by Keyword: Fe³⁺

Abstract: The magnetic properties of BaFeTiO₃ (BTFO) perovskite are investigated. BTFO samples were prepared by solid state reaction method through compression. Magnetic properties are influenced by electron environments of the Fe³⁺ ions within the perovskite structure. Furthermore, the values of Ms and Mr indicate ferromagnetic behaviour in BFMO ceramics sintered at 800 oC for sintering as 800 oC for 6 hours at 1.898 emu/g, which is magnetization strength material more than sintering at 4 hours, 8 hours, 10 hours as 1.794 emu/g, 1.333 emu/g and 1.192 emu/g at measured of low temperature. Using the Curie-Weiss law fitting for investigate μeff~38μB high spin of Fe, negative of θ present to antiferromagnetic characteristics of BTFO sample. Finally, BTFO sintering at the high temperature of 800 oC for 6 hours exhibited the high Ms~1.898 emu/g at 50 K and ~1.216emu/g at room temperature.

Abstract: Effects of different carbon source and Fe³⁺ for the growth and lipid accumulation of Monoraphidium sp. FXY-10 cultured mixotrophically was studied in our present work. The final cell density was reached to 2.626 g L^-1 when glucose was the only carbon source, which is 1.43-fold to sodium acetate (1.834 g L^-1), far higher than sucrose (0.251 g L^-1) and xylitol (0.471 g L^-1), but barely grow in other culture condition. Additionally, the highest algae lipid productivity (77.45 mg L^-1 d^-1) was obtained in 10 g L^-1 glucose group, which indicated that glucose was the optimal carbon source for growth and lipid accumulation of Monoraphidium sp. FXY-10. Nevertheless, Monoraphidium sp. FXY-10 was grew slowly in BG-11 culture medium with the absence of Fe³⁺. The biomass was achieved at the top with 50μM Fe³⁺ added. With the increase of Fe³⁺ concentration, it showed no variation in the growth of microalgae. The highest biomass productivity (209.87 mg L^-1 d^-1) was reached when the Fe³⁺ concentration was at 150μM while highest lipid productivity (94.05 mg L^-1 d^-1) reached at 50μM, which indicated that Fe³⁺ was one of the most indispensable trace elements for the growth and lipid accumulation of Monoraphidium sp. FXY-10.

Abstract: This study investigated the effect of ultraviolet (UV) enhancement and the Fe³⁺-EDTA Complex on the degradation of methylene blue (MB) in Fenton-like system. By studying different variables including H₂O₂ concentration, Fe³⁺-EDTA concentration and pH value，and using MB as a model pollutant, the best experimental conditions was to investigated. Experimental results showed that it is possible to degrade MB wastewater effectively by modified UV-Fenton with Fe³⁺-EDTA at neutral pH. Besides, optimality condition (pH= 7, [Fe³⁺-EDTA] = 2 mmol/L, [H₂O₂] = 10 mmol/L) which were used in the modified UV-Fenton that achieves a removal of over 95% of the MB in 60 min reaction time. Therefore, this new modified Fenton system is an effective treatment for MB wastewater.

Abstract: Fe³⁺/Ce⁴⁺ doped TiO₂ particles was prepared and used for degradation of phenol solution, the macrokinetics and mechanism of degradation process was proposed by GC-MS, and Fe³⁺/Ce⁴⁺-doped TiO₂ particles before and after treated phenol was also compared by TEM. The experimental results showed that COD degradation reactions in static and dynamic cycle process are in accordance with first-order kinetics from the macro effects, phenol can be oxidized to intermediates, such as isobutyric acid, malonic acid, para-benzoquinone, butenic acid, ethanedioic acid, maleic acid, butanedioic acid, o-dihydroxybenzene, paradioxybenzene and dioxybenzene, indicating that Fe³⁺/Ce⁴⁺-doped TiO₂ particles are beneficial to some oxidation formation. Moreover, the shapes of Fe³⁺/Ce⁴⁺-doped TiO₂ particles after treated phenol displays aggregated.

Abstract: In the bacterial leaching, the oxidation of Fe²⁺ is very important process. According to the results of this paper, Fe²⁺ and Fe³⁺ concentration effect on the growth of moderate thermophile. The optimum conditions for growth of moderate thermophile are the initial concentration of Fe²⁺ at 0.16mol/l. It indicates the existence of the optimum conditions including initial concentrations of Fe²⁺ and Fe³⁺ for the bio-oxidation Fe²⁺. To increase the initial concentration of Fe³⁺ can enhance the oxidation rate of Fe²⁺. The dynamic model of the moderate thermophile oxidation Fe²⁺ has been established by analyzing and calculating test data with the Matlab software.

Abstract: The method of activated sludge has been widely used in the process of sewage treatment for its high-efficiency and low-consumption. The effect of Fe³⁺ on microbial growth and physical and chemical properties of activated sludge were studied to obtain relevant parameters for the running of activated sludge system in this paper. Firstly, study on the effect of Fe³⁺ on microbial growth was carried out. The experiment results showed that the lag phase of microbial growth was obviously reduced with the presence of Fe3+, obtaining advancing into the logarithmic phase. Whats more, the value of OD600 reached to the maximum of 0.615 at 12h when the concentration of Fe³⁺ was 30mg/L. Secondly, the effects of Fe³⁺ on the wastewater treatment and that of the performance index include SVI and MLSS were studied. The results indicated that SVI decreased with increasing the dosages of Fe³⁺,while MLSS and removal rate of COD obviously increased which reach to the maximum of 88.21% when the concentration of Fe³⁺ was 30mg/L.

Abstract: 1, 4-dithiothreitol (DTT) combined with nanogold (AuNP) to form the DTT-AuNP probe in the solution of 1.0 mmol/L H₂SO₄. In the presence of Fe³⁺, the DTT-AuNPs aggregated to big particles that exhibited a maximum Resonance Rayleigh scattering (RRS) peak at 770 nm. Under the chosen conditions, the increased intensity was linear to Fe³⁺ concentration in the range of 7.3-149.5µg/L, with the regression equation of ΔI770nm = 127.5C +11.2, the correlation coefficient of 0.9954 and the detection limit of 3.75 ug/L Fe³⁺. The proposed method was applied to detect trace Fe³⁺ in water samples, with satisfactory results.

Abstract: The static adsorption of stainless steel pickling wastewater by ion resin exchange and activated carbon adsorption was studied respectively. The results shown that, the static saturate adsorption capacity of 001×7 dry resin for Cr3+and Fe3+ in the wastewater was 60.34mg/g and 65.3mg/g respectively, and the elution rate of saturated resin by using Na2SO4 and H2SO4 can reach 99%. The saturate adsorption capacity of activated carbon for Cr3+and Fe3+ in the wastewater was 4.55 mg/g and 40.76 mg/g respectively, and NaOH as desorption reagent had a good desorption effect to activated carbon. The regeneration of activated carbon was also carried out.

Abstract: To obtain a TiO₂ photocatalyst with high photocatalytic efficiency under visible irradiation and good reusability, the Fe³⁺ and N co-doped TiO₂ micro/nano fiber films were fabricated by electrospinning and calcinations. The morphologies and structures of the resulting samples were analyzed by scanning electron microscopy (SEM), x-ray diffraction and x-ray energy dispersion spectroscopy (EDS). The absorbance and chemical oxygen demand (COD) were characterized respectively by UV–visible spectrophotometer and COD Rapid Tester. The results show that the Fe³⁺ and N co-doped TiO₂ micro/nano fiber had a multi-porous structure with an average diameter of about 45 to 506 nm. The crystalinity degrees, visible light absorption of these films were affected by the dosage of Fe³⁺ and N co-doping (DFN). Moreover, these films exhibited high photocatalytic activity for the degradation of dye waste water under sunlight and it was related to DFN. As DFN was 0.5 %, it has highest crystalinity degree, largest visible light absorption and highest photocatalytic efficiency on dye waste water. The decolor rate of the dye waste water was as high as 67.6 % and its COD decreased from 2800±200 to 236.40 ± 15.61, when the photocatalytic time was only 3 h.

Abstract: LiFePO₄/C was synthesized from a gel precursor with ferric iron and an organic chelating agent as carbon source. Reductive atmosphere of N₂ + H₂ with H₂ content of 0-20 vol % was used in the sintering process of LiFePO₄/C composites. The microstructures of the obtained LiFePO₄/C particles were characterized by X-ray diffraction, field emission scanning electron microscopy, element analysis and particle size analysis. The results showed that suitable reductive sintering atmosphere was needed to get pure LiFePO₄/C phase, but too strong reducibility led to the formation of iron phosphides, most of which was Fe₂P. The amount of Fe₂P increased with the increase of H₂ content in the sintering atmosphere. The rate capability of LiFePO₄/C was improved when the sintering atmosphere became more reductive, while the discharge capacity of 0.1C decreased, which was probably due to the appearance of Fe₂P phase.