Influence Of Iron Ions Research Articles

Research on Metal Corrosion Behaviour of Indirect Air-cooled Circulating Water System

Abstract The indirect air cooling system of an air-cooled power plant consists of a surface condenser and an aluminum radiator. The radiator is usually made of 1050A pure aluminum, and the circulating water pipe connecting the radiator is made of Q235B carbon steel. This article simulates and controls typical water quality parameters such as dissolved oxygen and pH value in indirect air cooling systems using a self-designed simulation device, and studies the influence of various water quality parameters on material corrosion behavior in intercooled circulating water systems when aluminum and carbon steel coexist. The results indicate that factors such as dissolved oxygen, conductivity, pH value, temperature, and redox potential can all affect the corrosion rate of carbon steel and aluminum materials; The increase in temperature and dissolved oxygen leads to an increase in corrosion rate; The main way carbon steel corrodes the system is by consuming dissolved oxygen; The corrosion behaviour in the water circuit will lead to an overall decrease in pH value. In the presence of multiple metals, the influence of iron ions in the solution significantly increases the corrosion rate of aluminum.

The Influence of Iron Ions on Optical Brighteners and Their Application to Cotton Fabrics.

The influence of iron ions at concentrations of 0.2, 0.5, and 1.0 g/L on optical brighteners of the groups stilbene and biphenyl in solution and on cotton fabric was investigated. Both groups of optical brighteners are intended for detergent formulations. The influence of iron ions was studied by absorption and fluorescence spectra in solution and by whiteness degree, identifying color differences using CIEL*a*b* coordinates and Ultraviolet Protection Factor (UPF) of cotton fabrics. The obtained results in solutions and cotton fabrics showed different behavior of optical brighteners stilbene and biphenyl in the presence of iron. Stilbene compounds with metal ions produced new species capable of absorbing in the UV-B region of the spectrum. A biphenyl compound in combination with iron had no effect on the absorption properties. Both optical brighteners were influenced by iron ions in the sense of fluorescence quenching. The influence of iron ions in single- and two-bath treatments of cotton fabrics after one cycle on whiteness degree and UPF was negligible.

High-precision and on-line measurement of dissolved organic matter in Electro-Fenton process based on dual wavelength analysis with combination of fluorescence emission and ultraviolet absorption spectroscopy

Electro-Fenton (EF) process is a significant water treatment method for the degradation of dissolved organic matter (DOM) in water and has been widely studied and applied in the past decade to degrade various dissolved organics. During water treatment, in order to monitor the degradation efficiency, it is in dire need to develop rapid and accurate methods that are favorable to assay on-line and on-site to provide feedback in a timely manner. UV–Visible absorption spectroscopy and Excitation-Emission Matrix (EEM) fluorescence spectroscopy techniques are most potential to realize on-line DOM measurement, but the measurement accuracy is unsatisfactory because of the obligatory involvement of iron-containing interferents. This study aims to simplify the measurement system complexity while overcoming the effect of iron-containing interferents during the measurement. An intrinsic relationship between the measured DOM concentration and the ultraviolet absorption at λ1 and the light intensities of the fluorescence emission at λ2 is derived theoretically and proved, based on which the influence of iron ions and their complexes on the spectrum can be eliminated, thus the content of DOM in the Electro-Fenton process is accurately determined. The proposed dual wavelength analysis with combination of fluorescence emission and ultraviolet absorption spectroscopy can achieve high precision (R2=0.9882,RMSE=0.0131mg/L). Furthermore, the on-line measurement design, called ultraviolet absorption-fluorescence emission dual wavelength analyzer, only includes one ultraviolet LED and two photodetectors. Its structure is simple and suitable for on-line monitoring DOM in EF process.

Removing Iron and Organic Substances from Water over the Course of Its Treatment with the Application of Average and Highly Alkaline Polyaluminium Chlorides

In topic-related literature pertaining to the treatment of water, there is a lack of information on the influence of iron ions in highly basic polyaluminum chlorides on the efficiency of purifying water with increased contents of organic substance. The aim of this work was to determine the changes in the content of organic substances as well as iron compounds in water intended for human consumption following unit treatment processes with particular attention paid to the coagulation process. As coagulants, polyaluminium chloride PAXXL10 with an alkalinity of 70%, as well as polyaluminium chloride PAXXL1911 with an alkalinity of 85% the composition of which also contained iron, were tested. The analysis of the obtained results showed that iron compounds and organic substances were removed to the greatest extent by the coagulation process, which also had a significant influence on the final efficiency of water treatment. The effectiveness of water treatment was determined by the type of tested polyaluminum chloride, which influenced the formation of iron-organic complexes. The reason behind the formation of colored iron-organic complexes during coagulation using PAXXL1911 coagulant was the high pH (approx. 8), at which the functional groups of organic substances, due to their dissociation, are more reactive in relation to iron, and possibly the fact of introducing additional iron ions along with the coagulant.

Influence of iron ions on morphology and magnetic and electrical properties of vanadium dioxide

Influence of iron ions on morphology and magnetic and electrical properties of vanadium dioxide

The influence of iron ions on ATP-hydrolases activity of cell membranes of rat colon smooth muscle and kidney

To elucidate the specific features of the ATP-hydrolases structural resistance in the membrane under the action of the prooxidants: Fe2' and hydrogen peroxide, and N-ethylmaleimide (NEM) the colonic smooth muscle (CSM) Na+, K(+)-ATPase activity was compared with activities of the corresponding Mg(2+)-ATP-hydrolase and ATPases from kidney medullar layer of rats. The inhibition study of the CSM Na+, K(+)-ATPase by divalent iron shows the decrease of the activity by 30% at 0.1 μM FeSO4 and in the range of 0.1-10 μM--to 45% of residual activity. When comparing with kidney enzyme (rep- resents exclusively α1-isozyme) the CSM Na+, K(+)-ATPase sensitivity to Fe2+ is reliably higher at its submicromolar concentration. CSM Mg2+-ATPase is much more resistant to iron ions effect, than kidney one. However for two tissues Mg2(+)-ATPase activity is always more resistant as compared with corresponding Na+, K(+)-ATPase activity. Against 1 mM EGTA Na+,K(+)-ATPase and Mg2(+)-ATPase activities of GMOK and kidneys are equally insensitive to effect of hydrogen peroxide in concentration up to 1 mM. But in the presence of 20 μM FeSO4 in the concentration range of 1 nM-1 mM of H2O2 the Na+, K(+)-ATPase is inhibited to greater extent, than Mg2+-ATPase activity. NEM sensitivity of the two ATP-hydrolase systems corresponds to prooxidant sensitivity that indicates the distinct importance of SH-groups for their functioning. It is concluded that Na+, K+-ATPase can serve as a marker of membrane sensitivity to oxidation, Mg(2+)-ATPase is resistant to oxidation and can be considered as criterion of the oxidation resistance when comparing membrane enzyme complexes, es- pecially in GMOK.

Sensitization of Photosemiconducting Properties of Holographic Recording Media Based on Glycidylcarbazole Cooligomers by Organic Dyes

Photophysical and information properties of the holographic recording media (HRM) based on films of ferrocenyl-containing siloxane oligomer, glycidylcarbazole-butylglycidylic ether cooligomer, ferrocenemethylated oligoglycidylcarbazole, and cooligomer of o-carboxybenzoilferrocene glycidylic ether doped with squarilic dye and(or) with merocyanine dye based on ferrocene and tetranitrofluorene are investigated. It is found that the holographic sensitivity is absent for the media based on ferrocenyl-containing siloxane oligomer, and that the holographic sensitivity is present for the films based on glycidylcarbazole. It has been found that the holographic sensitivity and the photoconductivity of the media based on glycidylcarbazole cooligomers increases with the ferrocene content. This effect has been explained by the influence of iron ions on the rate of singlet–triplet conversion in photogenerated pairs of charges.

Influence of iron ions on the structural and magnetic properties of some zinc-phosphate glasses

Glasses in the (Fe 2O 3) x ·(P 2O 5) 40·(ZnO) 60− x (0 ≤ x ≤ 30 mol%) system have been prepared by the melt-quenching technique. The structural and magnetic properties of these glasses were investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, electron paramagnetic resonance (EPR) and magnetic susceptibility measurements. The XRD pattern for the prepared samples shows their vitreous state only for x ≤ 20 mol%. For the samples containing 30 mol% Fe 2O 3 the presence of a unique crystalline phase, FePO 4, embedded in an amorphous matrix was evidenced. FTIR spectroscopy data suggest that the iron ions play the network modifier role in the studied glasses. The addition of iron oxide leads to the breakage of P O bonds and the formation of the P–O–Fe bonds. The presence of the Fe–O–P bonds for the samples with higher iron oxide content in the studied system improves their chemical durability. The increases of iron ions content of the samples determine a gradual decrease in the number of bridging oxygen ions respectively the increase of the number of non-bridging oxygen ions. EPR and magnetic susceptibility measurements show the presence of the Fe 3+ ions in sites of distorted octahedral symmetry and as well as in clustered formations containing both Fe 3+ and Fe 2+ ionic species. Dipolar and superexchange interactions involving iron ions were revealed depending on the iron content of the sample.

Influence of iron ions on dielectric properties of the PbO–Bi2O3–B2O3 glass system

PbO–Bi2O3–B2O3 glasses containing small concentrations of Fe2O3 (0–1 mol%) were subject to dielectric studies (dielectric constant ε′; loss tan δ; and ac conductivity σ ac) over a wide range of frequency and temperature. From spectroscopic (infrared, optical absorption and ESR spectra) and magnetic susceptibility studies, variations in these properties with dopant ion concentration were analyzed in terms of different oxidation states and iron ion environment in the glass network.

Influence of iron ions on the magnetic properties of CaO–SiO 2–P 2O 5–Na 2O–Fe 2O 3 glass–ceramics

Room temperature Electron Paramagnetic Resonance (EPR) spectra and temperature dependent magnetic susceptibility measurements have been performed on 41CaO.(52− x)SiO 2.4P 2O 5. xFe 2O 3.3Na 2O ( 2 ≤ x ≤ 10 mol % ) glass–ceramics. The parent glass samples were prepared by quenching the homogenized melt from 1550 ∘C. The glasses were then heat-treated at 1050 ∘C for 3 h and slowly cooled to room temperature to yield glass–ceramics. EPR and high temperature magnetic susceptibility measurements were made to elucidate the state of Fe +3 ions in the glass–ceramics. The EPR absorption line centered at g ≈ 4.3 disappeared at higher concentrations of Fe 2O 3. The intensity and linewidth of the absorption line centered at g ≈ 2.1 increased as the Fe 2O 3 concentration was increased. Information about the structural changes involving iron ions, their valence state and type of magnetic interactions between the Fe ions was obtained using EPR and magnetic susceptibility measurements. The temperature dependence of the magnetization of the glass–ceramics with low Fe 2O 3 concentrations exhibit both ferrimagnetic and paramagnetic contributions. The results obtained have been used to understand the structural changes occurring in the vicinity of iron ions and the nature of magnetic interactions between the iron ions in these glass–ceramics.

Influence of iron ions on the phenol oxidation

An influence of iron ions presence in water contaminated with phenol on phenol degradation induced by the corona discharge in air-like gas mixture was studied. DC positive corona discharge was generated between a hollow needle, through which air with 1.5 % CO2 flowed, and the water surface. Concentration of phenol and iron sulphate in water was 0.6 mM and 0.08 mM, respectively. It was observed that phenol degradation was not enhanced by the presence of iron ions. There was no Fenton reaction producing OH radicals, in spite of significant production of hydrogen peroxide. Instead of going into Fenton reaction with hydrogen peroxide molecules, iron ions react with ozone which is produced in gas phase and then dissolves in water.

Evidence that intrinsic iron but not intrinsic copper determines S-nitrosocysteine decomposition in buffer solution

The present experiments were designed to analyze the influence of copper and iron ions on the process of decomposition of S-nitrosocysteine (cysNO), the most labile species among S-nitrosothiols (RSNO). CysNO fate in buffer solution was evaluated by optical and electron paramagnetic resonance (EPR) spectroscopy, and the consequences on its vasorelaxant effect were studied on noradrenaline-precontracted rat aortic rings. The main results are the following: (i) copper or iron ions, especially in the presence of the reducing agent ascorbate, accelerated the decomposition of cysNO and markedly attenuated the amplitude and duration of the relaxant effect of cysNO; (ii) by contrast, the iron and copper chelators bathophenantroline disulfonic acid (BPDS) and bathocuproine disulfonic acid (BCS) exerted a stabilizing effect on cysNO, prolonged its vasorelaxant effect, and abolished the influence of ascorbate; (iii) in the presence of ascorbate, BPDS displayed a selective inhibitory effect toward the influence of iron ions (but not toward copper ions) on cysNO decomposition and vasorelaxant effect, while BCS prevented the effects of both copper and iron ions; (iv) l-cysteine enhanced stability and prolonged the relaxant effect of cysNO; (v) the process of iron-induced decomposition of cysNO was associated with the formation of EPR-detectable dinitrosyl–iron complexes (DNIC) either with non-thiol- or thiol-containing ligands (depending on the presence of l-cysteine), both of which exhibiting vasorelaxant properties. From these data, it is concluded that the amount of intrinsic copper was probably too low to produce a destabilizing effect even on the most labile RSNO, cysNO, and that only intrinsic iron, through the formation of DNIC, was responsible for the process of cysNO decomposition and thus influenced its vasorelaxant properties.

モリブデン酸塩の軟鋼の腐食抑制に及ぼす鉄イオンの影響とその対策

モリブデン酸塩の軟鋼の腐食抑制に及ぼす鉄イオンの影響とその対策

Influence of iron ions on the structural properties of Zn-borosilicate glasses

The effects of iron on the structural properties of Zn-borosilicate glasses have been studied using X-ray diffraction, IR spectroscopy and57Fe Mossbauer spectroscopy. Zn-borosilicate glasses were doped with α−Fe2O3. In the systems Na2O−ZnO−B2O3−SiO2−Fe2O3 the presence of only one crystalline phase, ZnFe2O4, was detected. X-ray diffraction showed that crystallization is more pronounced in the systems ZnO−B2O3−SiO2−Fe2O3. In these systems the presence of different crystalline phases, such as ZnO, γ−Fe2O3, Fe3O4, ZnFe2O4 and Fe3BO5, was detected. The crystallization of α−Zn2SiO4 in the system ZnO−B2O3−SiO2 was confirmed by X-ray diffraction and IR spectroscopy. The valence state and coordination of iron in Zn-borosilicate glasses were determined by57Fe Mossbauer spectroscopy.

Influence of iron ions on the structural properties of some inorganic glasses

The effects of iron on the structural properties of Zn-borosilicate glass and Pb-metaphosphate glass were studied using X-ray diffraction,57Fe Mossbauer spectroscopy and IR spectroscopy. Zn-borosilicate glass was prepared with varying amounts of Fe2O3 (up to 30% wt.). It was found that the chemical form of added iron (α-FeOOH, α-Fe2O3 or Fe3O4) affects the Fe3+/Fe2+ ratio, as well as the distribution of iron ions at different coordination sites. At high concentration of iron the crystallization of zinc ferrite in the glass matrix takes place. X-ray diffraction and57Fe Mossbauer spectroscopy showed that the amount of zinc ferrite in Zn-borosilicate glass decreases with the following order of addition: α-FeOOH→α-Fe2O3→Fe3O4. In Pb-metaphosphate glass doped with high concentration of α-Fe2O3, the crystallization of Fe3(PO4)2 is pronounced. The assignments of IR band positions and the corresponding interpretation are given. The importance of this study for the technology of vitrification of high-level radioactive wastes is emphasized.

The Significance of Lead and Iron Ions for the Photographic Process

AbstractThe method described previously for investigating the action of different addenda on the photosensitivity of silver bromide crystals has been used to study the effect of lead and iron ions on both stages of the photographic process. It is established that lead ions have a catalysing effect on the process of development and promote the latent image formation. Iron ions have an adverse effect on the two stages of the photographic process : although hindering the process of development, they have a strongly marked sensitizing effect on the latent image formation. The influence of iron ions on sensitized crystals has also been followed. The mechanism of the action of the addenda is discussed.