Papers by Keyword: Fe²⁺

Abstract: By solid phase microextraction - Gas Chromatography - mass spectrometry (SPME-GC-MS) technique against acid and methionine bad blood (ASA-Met) model of the reaction products were identified, studied the effect of Fe²⁺ on the formation of flavor compounds in the model reaction. 27 flavour compounds of furan, pyrazine, thiophene, sulfur and other compounds, were identified, of which, sulfur-containing compounds such as aliphatic cyclic sulfides, sulfide, pyrazine is the main flavor components. Fe²⁺ was added to the model in the system, on one hand the about adding some sulfur compounds yield, pyrazine compounds significantly increase; on the other hand, Thiophenes significantly reduced compounds or even disappear. This shows that in the model reaction, Fe²⁺ promotes the thermal degradation of Met, at the same time, suggesting that Fe²⁺ as oxidant to promote NH₃, NH₃ and H₂S to generate competitive reaction and ASA degradation products formed compounds containing nitrogen, resulting in reduced Thiophenes compounds yield.

Abstract: By experiments, separate and purify efficient sulfate—reducing bacteria (SRB), which is identified as Desulfobacter. With its treatment of acid mine drainage(AMD) containing Fe²⁺ and Mn²⁺, obtain the optimum conditions that pH=6,temperature=37,vibrating intensity=100r/min, COD/SO₄^2- =2.Under this condition ,the removal rate of SO₄^2-、Fe²⁺ and Mn²⁺ is 88.16%、99.37% and 59.18% respectively with the initial concentration 1411mg/L for SO₄^2-,257mg/L for Fe²⁺ and 325mg/L for Mn²⁺.This puts a theoretical foundation for the further study.

Abstract: The polyvinyl alcohol (PVA) wastewater was pretreated by the process of flocculation-Fenton oxidation. Raw wastewater was treated by the different flocculants first. The results showed that when the flocculant FeSO₄ was used, its effect was better than Fe₂(SO₄)₃ and PAC, the dosage of it was 10g/L, under which COD removal efficiency reached 61.72%. The effects of FeSO4 and H₂O₂ addition and pH on treatment effect were studied in the follow-up Fenton oxidation. The results showed that when the addition of FeSO₄ was 20g/L, the dosage of H₂O₂ was 250mL/L, pH was 4, the removal efficiency of COD reached over 90%. The experiments of fractionated adding the reagents showed that the removal rate of COD was significantly higher in the situation of fractionated adding FeSO₄ required in the flocculation and Fenton oxidation process than one-time added. The removal rate of COD changed little when the H₂O₂ fractionated addition in the process of Fenton oxidation.

Abstract: Twenty-eight yellow-green color of uniform, high clarity and similar thickness of 5 mm × 7 mm oval faceted peridots from Jiaohe Jilin province were examined by LA-ICP-MS and Color i5 to test their chemical compositions and L^*, C^* and ho. The correlations between Fe²⁺ and color parameters were analyzed, in order to establish the influence on the color appearance of Fe²⁺. The chemical formula of the twenty-eight peridots is (Mg_1.84,Fe_0.19)_2.04[(Si_0.982,Al_0.001)_0.983O₄], which was calculated by oxygen atom. It reveals that 0.19 mol Fe²⁺ is concluded in one mol peridot, and Fe²⁺ is the colorant of peridot. Based on the CIE 1976 L^*a^*b^* uniform color space, relationships between chromaticity coordinates a^*, b^* and chromaticity C^* were analyzed by Two-way ANOVA, of which the results showing that the influence of b^* on C^* (r_b*×C*=0.996) is much more prominent than a^* on C^* (r_a*×C* = -0.383). By partial correlation analysis of the results calculated through CIE LAB color-difference formula, it can be discovered that lightness difference DL^* has a better correlation with chromatic aberration DE^* than DC^* and DH^*, whereas the significance level ρDC*×DE* > 0.05, rDH*×DE* > 0.05, it reveals that DE^* is more sensitive to DL^*. At the same time, L^* changes the most with the contributions of Fe²⁺ compared with other parameters of peridot. It is concluded that, with the help of L^*, Fe²⁺ has a further influence on the color appearance of peridot.

Abstract: Ferrum is one of the important nutrient sources for algae in lakes. The changes of concentration in water body have great effect on the formation of dominant algae. Microcystis aeruginosa, Scenedesmus quadricauda and Cyclotella were examined in M11 culture medium which included different Fe²⁺ and Fe³⁺ concentration. Growth curves of these three algae were fitted by logistic growth-model, respectively. The maximum biomass K, inflection t and growth rate µ of those algae were investigated. The effects of Fe²⁺ and Fe³⁺ on the growth of algae were investigated by using the Monod equation. The semi-saturation constants were calculated. The results showed that the maximum biomass of these three algae did not increase with the increasing of Fe²⁺ and Fe³⁺ concentration. Low concentration of Fe²⁺ (200-500 mg/L) and high concentration of Fe³⁺ (2000-5000 mg/L) were more suitable to the growth of three algae. The sequence of the maximum biomass was: Scenedesmus quadricauda>Microcystis aeruginosa>Cyclotella.

Abstract: Objective: Establishment the iron (Ⅱ), iron (Ⅲ) the content determines separately method in haematitum.Methods: Sample decomposition with hydrochloric acid and potassium fluoride. Determined the content of iron in different characters mineral medicine haematitum by UV-vis spectroscopy, pH3~5, wavelength 396nm；Determined the content of Fe2+, Obtained the content of Fe3+ by concentration difference. Results: This method is easy to do.The accuracy is good.The returns-ratio is high.The method may take the haematitum quality the control standard.

Abstract: This study investigated the effects of Fe2+ on the cell growth and hydrogen production to Biohydrogenbacterium R3 sp.nov. in the batch test. The hydrogen production got the maximum of 12.54mmol/L when the concentration of Fe2+ was 40 mg/L and the hydrogen content, OD600nm, glucose consumption and the concentration of ethanol had the maximum of 45.2 %, 1.31 g/L, 92 % and 1073.34 mg/L respectively when the concentration of Fe2+ was 100 mg/L. The phenomenon of feed back appeared when the concentration of Fe2+ exceeded 100 mg/L.