Iron Chloride Solution Research Articles

Separation of the tin finding forms and determination of the organotin compounds total content in natural waters of different salinity

In the current paper, the possibility of separating inorganic and organic forms of tin occurrences has been considered and the features of determining the total content of organotin compounds (OTC) in waters with different salinities by ICP-spectrometry with hydride generation were studied. Various approaches to the separation of the chemical forms of tin by liquid-liquid extraction with various solvents, as well as by precipitation with fluorides, iodides, aqueous solutions of ammonia and iron (III) chloride at analyte concentrations at the MPC level for fishery reservoirs, have been examined. The separation of the chemical forms of tin due to the taking out the OTC by liquid-liquid extraction turned out to be inefficient because of the incomplete extraction of analytes and partial extraction (up to 15%) of the inorganic form of tin into the organic phase. Precipitation of inorganic and organic forms of tin using fluorides, iodides, ammonia, and iron (III) chloride also turned out to be inefficient. This was due to the low content of analytes, at which their quantitative precipitation was difficult. Under the conditions of high-level mineralization of sea waters, it was also unlikely that a competing reaction of changing the chloride environment to fluoride or iodide one would occur. Separation of the chemical forms of tin was achieved using the solid phase sorption. The Diapak C18 silica gel sorbent selectively extracted the organic form of tin from waters with different salinity under the optimized conditions. The optimized conditions for separating the chemical forms of tin made it possible to develop a method for determining the total content of OTC in natural waters with different salinity from the difference between the total content of the analyte and the inorganic form of tin. To determine the total content of the analyte, microwave mineralization of the water sample was carried out; the concentration of the inorganic form of tin was determined after its solid-phase separation from organotin compounds. The lower limits of analyte concentrations determined were 0.03 and 0.05 μg/dm3 for the ICP-MS and ICP-AES methods, respectively, which made it possible to separately determine the OTC during the ecoanalytical monitoring at the level below the MPC.

Analysis of sorption capacity of natural sorbents in relation to aqueous solutions of heavy metal compounds

The main preconditions emergence of an environmental crisis in the country due to surface water pollution include irrational use of water resources in violation of the environmental requirements, discharge of untreated and insufficiently treated industrial and municipal wastewater into water bodies and inflow of polluting substances from agricultural lands as a result of surface water drainage. The whole set of considered factors leads to depletion and pollution of surface water of Ukraine, reduction of their self-cleaning capacity, degradation, impoverishment and collapse of aquatic ecosystems.
 Excessive content of heavy metal ions in surface water has a negative impact on the environment, causing acute and chronic diseases. Ingress of such pollutants into surface water is almost entirely due to anthropogenic economic activity. Wastewater from chemical, ferrous and nonferrous metallurgy brings a great amount of such pollutants.
 Among various methods used for removing heavy metal ions from aqueous media, sorption methods remain one of the most effective and popular, mainly due to the fact that they ensure a high degree of purification at relatively low costs. Along with the adsorbents traditionally involved in these processes, a number of studies and practical implementations with use of natural dispersed minerals as adsorbents were conducted lately.
 The research aims at studying the sorption capacity and efficiency of natural and modified sorbent such as bentonite clay for purification of aqueous solutions containing heavy metal ions in the form of dissolved compounds and justifying its potential application.
 It studies the efficiency of wastewater treatment aimed at removing heavy metal ions by the natural clay sorbent of bentonite clays of the Cherkaskyi Deposit (Dashukovskyi deposit).
 The paper presents a technique for modification of bentonite clay in order to increase its adsorption capacity for heavy metal ions using the following three methods: physical (thermal), chemical (processing with application of Iron(III) chloride solution) and combined (thermal processing of the original sorbent followed by processing with application of Iron(III) chloride solution).
 It has been experimentally proved that a natural sorbent modified via thermal and chemical processing is characterized by a high absorption capacity to heavy metal ions contained in water solutions, in particular to chromium(VI) ions, copper(II) ions and aluminum(III) ions with the purification degree ranging from 5% to 83%. The highest adsorption rate, 83%, is demonstrated by the combined method of bentonite clay modification, therefore proving the effectiveness of application of environmentally friendly natural sorbents for wastewater treatment processes aimed at removing heavy metal ions. The paper indicates the advantages of wastewater treatment sorption methods allowing removal of pollutants of different origin and any concentration.

Production of fibers based on polyacrylonitrile with magnetite nanoparticles

The paper presents the results of experiments on the production of composite fibers based on polyacrylonitrile (PAN) and magnetite. For this, magnetite nanoparticles were synthesized by the method of chemical condensation from iron (III) chloride solutions with a concentration of 0.32 mol/l and iron sulfate with a concentration of 0.2 mol/l by gradually adding a 25 % aqueous ammonia solution. It was shown that a simple deposition method can be used to synthesize homogeneous nanoparticles of Fe3O4 magnetite with a particle size of 8–25 nm. This is confirmed by the results of X-ray phase analysis and transmission electron microscopy. Magnetite nanoparticles were then used to obtain PAN/Fe3O4 composite fibers by adding magnetite in a 7 wt.% PAN solution in dimethylformamide. Fibers were obtained from the PAN/Fe3O4 suspension in dimethylformamide by electrospinning. Scanning electron microscopy showed that magnetite nanoparticles are uniformly distributed throughout the fiber surface, and the fiber size is 288–658 nm. The comparison of PAN fibers without the magnetite additive and PAN/Fe3O4 fibers showed that the addition of magnetite leads to a decrease in the fiber diameter at the same polymer concentrations and electrospinning conditions. XRD and elemental analysis of PAN/Fe3O4 fibers showed that magnetite particles in the fibers did not change their chemical composition and represent single-phase magnetite in a polymer matrix. The results obtained in the studies showed the possibility of obtaining composite fibers based on magnetite by the electrospinning method. Resulting composite fibers may be useful in practical scientific and engineering applications.

Iron Stearate Structures: An Original Tool for Nanoparticles Design.

Iron carboxylates are widely used as iron precursors in the thermal decomposition process or considered as in situ formed intermediate precursors. Their molecular and three-dimensional (3D)-structural nature has been shown to affect the shape, size, and composition of the resulting iron oxide nanoparticles (NPs). Among carboxylate precursors, stearates are particularly attractive because of their higher stability to aging and hydration and they are used as additives in many applications. Despite the huge interest of iron stearates, very few studies aimed up to now at deciphering their full metal-ligand structures and the mechanisms allowing us to achieve in a controlled manner the bottom-up NP formation. In this work, we have thus investigated the molecular structure and composition of two iron stearate precursors, synthesized by introducing either two (FeSt2) or three (FeSt3) stearate (St) chains. Interestingly, both iron stearates consist of lamellar structures with planes of iron polynuclear complexes (polycations) separated with stearate chains in all-trans conformation. The iron content in polycations was found very different between both iron stearates. Their detailed characterizations indicate that FeSt2 is mainly composed of [Fe3-(μ3-O)St6·xH2O]Cl, with no (or few) free stearate, whereas FeSt3 is a mixture of mainly [Fe7(μ3-O(H))6(μ2-OH)xSt12-2x]St with some [Fe3(μ3-O)St6·xH2O]St and free stearic acid. The formation of bigger polynuclear complexes with FeSt3 was related to higher hydrolysis and condensation rates within the iron(III) chloride solution compared to the iron(II) chloride solution. These data suggested a nucleation mechanism based on the condensation of polycation radicals generated by the catalytic departure of two stearate chains from an iron polycation-based molecule.

“Urban Mines” Recycling in Astec-irie Co., Ltd.

This paper reviews recycling technologies in Astec-irie Co., Ltd. Repellent substances and valuable metals, such as precious metals and rare metals, contained in waste electronics were separated and concentrated using superheated steam, an aqueous iron (III) chloride solution, and AI. The electronic components and substrates were separated by melting the solder with superheated steam, and the repellent substance in non-iron smelting was removed from them. The gold-plated parts contained in the electronic components were separated back into gold by dissolving the copper and nickel in the aqueous iron (III) chloride solution. The copper and nickel dissolved into the solution were separated and recovered respectively as solid components by adding iron powder. The useful metals were concentrated from the separated electronic components, which are sorted out using AI. As a result, valuable metals such as precious metals could be concentrated while reducing the concentration of repellents, thus making it possible to treat the removed repellents as useful substance.

PHYSICOCHEMICAL IN-SITU SYNTHESIS OF PRUSSIAN BLUE FOR CESIUM REMOVAL

Prussian blue (PB) has attracted substantial attention as a potential adsorbent for radionuclides due to its high water-insoluble characteristics. Here, PB-encapsulating activated carbon fibers (ACFs) obtained via a physicochemical in-situ synthesis were introduced for an effective cesium removal. ACFs were used as an anchor platform to hold PB within the pores. The physicochemical synthesis of PB (PB-ACF-B) was done by stirring ACFs in an iron chloride solution. Potassium ferrocyanate was injected during the stirring process. As the counterpart, powdered PB (PB-ACF-A) was prepared with a physical synthesis. Throughout the test, PB-ACF-B revealed a decrease in the specific surface characteristics compared to PB-ACF-A; however, it also experienced an increase in the 133Cs adsorption. In all the cases, the dosage of the absorbent and radionuclide was in positive correlation with the adsorption performance. Further, the amount of PB was found to be the key factor for the adsorption of 133Cs compared to the specific surface characteristics.

Fabrication of iron oxide nanoparticles from ammonia vapor and their importance in plant growth and dye degradation

Iron oxide (Fe2O3) nanoparticles are of great interest compared to their bulk counterpart due to their higher surface area, enhanced possibilities of bio-distribution and high rate of reactivity. In the present work, we report a simple, rapid, and cost-effective method for the synthesis of Fe2O3 nanoparticles based on the aqueous-gaseous phase reaction of iron (III) chloride solution by ammonia vapor. Post-physicochemical characterization of these nanoparticles, we have further reported that these positive surface charged containing particles can increase the plant growth under in vitro conditions. Investigations on maize plant show that Fe2O3 nanoparticles could have potential as a fertilizer substituent. Moreover, these particles were found to exhibit good photocatalytic activity against Rhodamine B, indicating their potential use toward soil remediation affected with industrial wastewater from dye industries.

Direct Leaching of Lead from Galena Using Acetic Acid in Iron(III) Chloride

Abstract Investigations on the kinetics of leaching lead from galena (PbS), using acetic acid (HAc) solutions in iron(III) chloride (FeCl3) solutions, were conducted using shrinking core models. Th...

Development of the method for estimating complex formation using the electrochemical impedance spectroscopy on the example of the doxycycline and iron (III) interaction

The aim. To develop an EIS method for study the interaction between medicinal products and metal salts on the example of the Doxycycline and iron (III) interaction.
 Materials and methods. Measurements of the total impedance of the studied solutions have been performed using a vector circuit analyzer ZNB40 (Rohde & Schwarz, Germany). The calculations of electrical models were performed using the software package EC-Lab V10.40. Measurement cell was made of Teflon, 1 ml of volume, had 2 parallel nickel plated steel electrodes with diameter 6 mm, distance between electrodes is 9 mm. Basic electrical elements of model circuit were calculated according to type of electrochemical process that were described by Nyquist plot (RW, Rct, RS, Cd, CS etc.). Solutions were prepared immediately before the measurement. Measurements were performed at a temperature of 296±3 K. 6 control solutions of doxycycline and 6 control solutions of iron (III) chloride were prepared and measured. 11 study solutions at a molar ratio 1:6, 1:5, 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1 were prepared and measured. Concentration of the solutions was X∙10-3 mol/L respectively.
 Results. EIS analysis of Nyquist curves of study solutions in the range of molar ratios 1: 6, 1: 5, 1: 4, 1: 3, 1: 2, 1: 1, 2: 1, 3: 1, 4: 1, 5: 1, 6: 1 showed a change in the dynamics of electrical resistance at a ratio of 1:1. In the aqueous solution at T = 296±3 K the constant formation of the solution of doxycycline hyclate and iron (III) chloride is 2.9. This value of the complexation constant indicates that doxycycline hyclate forms a stable metal-ligand complex with iron (III) ions.
 Conclusions. EIS method can be applied to study the interaction of medicinal products. Model of this study was created on the example of doxycycline hyclate and iron (III) chloride. Metal-ion complexation of these two molecules was once again confirmed by using the EIS method

Stiffened and toughened polyacrylamide/polyanionic cellulose physical hydrogels mediated by ferric ions

High-strength hydrogels have recently attracted many attentions owing to their potential applications in various fields. Yet, how to relive the contradiction between strength and ductility is still a challenge. In this work, a series of Fe(III)-crosslinked polyacrylamide/polyanionic cellulose composite physical hydrogels [PAM/PAC-Fe(III)] were firstly prepared via polymerizing acrylamide in PAC solution free of chemical crosslinkers, and followed by posttreatment in 0.1 M iron chloride solution. The obtained hydrogels were characterized by FTIR spectroscopy and scanning electron microscopy as well as tensile and compressive mechanics. Herein, the mechanics of PAM/PAC-Fe(III) hydrogels exhibits both stiffened and toughened properties, benefitting from the synergy between hydrogen bonding and Fe(III)-COO- coordination interactions within the networks. Subsequently, their properties were compared with those of Zr(IV)- and cellulose nanofiber (CNF)-based analogues in our previous studies. Fe(III) species afford the hydrogels more flexibility than the Zr(IV) ones do due to the lower valency and weaker affinity of Fe(III) than those of Zr(IV); PAC-based systems demonstrate broader and/or higher mechanical reinforcement effects than CNF-based ones ascribing to higher carboxylate content and higher dosage of PAC than CNF. In brief, the present research provides an effective approach to fabricate simultaneously stiffened and toughened hydrogels and provides a guidance to rationally design metal-ion mediated PAM-based composite hydrogels.

Композитные мембраны с поверхностным слоем из ацетата целлюлозы для водоочистки и водоподготовки

Microporous composite membranes containing from one to three ultrathin layers were obtained by multistage immersion of a paper base in a solution of cellulose acetate in acetone. The physicochemical properties of membranes have been studied and the parameters of membrane separation of heavy metal ions from tap water have been determined. An increase in the particle size and a decrease in the absolute value of the ζ-potential with an increase in the concentration of cellulose acetate in acetone were revealed. It was found that the porosity of the membranes increased from 47 % to 51 % depending on the number of ultrathin cellulose acetate layers on the substrate surface. A decrease in the moisture absorption of composite membranes and an increase in the contact angle of wetting with distilled water from 30.0° to 68.8°, depending on the number of ultrathin layers, were noted. Microscopic examination of the membrane surface showed that the ultrathin layer consists of many pores with sizes less than 1 micron. The absorption bands in the IR spectra of cellulose acetate and the surface of the composite microporous cellulose acetate (MAC) membrane are identical. The retention capacity of MAC composite membranes, determined by iron ions from an iron (III) chloride solution, ranged from 47.5 to 97.4 % depending on the number of cellulose acetate layers on the substrate surface with a specific productivity of 27.9 to 7399 dm3/(m2·h) and a pressure of 0.35 MPa. A high selectivity of a microporous membrane of three layers of cellulose acetate (MAC3) with respect to heavy metal ions contained in tap water was established: Cr3+ (96 %) > Cu2+ (92 %) > Fe3+ (90 %) > Mn2+ (45 %).

Effect of Thermocycling and Mechanical Loads on Corrosion Resistance of High-Strength Nitrogen Austenitic Steels

The effect of long-term thermocycling and mechanical loads on the corrosion resistance of novel nitrogen austenitic Cr – Ni – Mn steels melted under laboratory conditions is studied in various aggressive environments. The steels are subjected to 400 thermal cycles in the temperature range from –100 to 100°C and to cyclic mechanical loading during 1 × 106 cycles. The structure and the mechanical properties of the steels after the cyclic loading are studied. Tests for resistance to general and pitting corrosion in sea water (3% NaCl) and in an acid environment (0.5M H2SO4 including blasting with hydrogen sulfide), to pitting corrosion in an aqueous solution of iron chloride, to intercrystalline corrosion in a test solution, to corrosion cracking under load, and for cavitation damage in a 3% solution of NaCl are conducted. It is shown that the developed high-strength nitrogen austenitic steels 10Kh19G10N6AM2 and 09Kh19G10N6AM2D2 both in the initial condition and after the thermocycling and cyclic mechanical loading have high resistance to the types of corrosion studied, which exceeds the resistance of steels 04Kh18N9 and 04Kh18AN9. Requirements on the composition and the structure of the steels are developed.

Spectrophotometric Monitoring of Chloride Electrolyte for the Electrochemical Deposition of Permalloy

The use of chloride electrolytes for the electrochemical deposition of the Ni81Fe19 permalloy is promising because sulfate electrolytes are unstable in the presence of sulfur. The magnetic properties of the Ni81Fe19 alloy are very sensitive to the deviation of the composition from the molar ratio of 4.26 between components. In this study, the accuracy of preparing the chloride electrolyte for the electrochemical deposition of a permalloy is controlled using spectrophotometry. Analysis of the spectra of light absorption and scattering by the iron hydroxide colloidal species of the electrolyte reveals that the electrolytic dissociation of bivalent iron and the mechanism of anomalous nickel and iron codeposition depend on the temperature and affect the electrochemical deposition of permalloy films. It is noted that the precipitation of ferrous hydroxide in the form of a colloidal species with boric acid as a complexing agent is a specific feature of ferrous chloride during hydrolysis. It is shown that, after filtrating iron chloride solution, nickel is precipitated from the chloride electrolyte better than iron. It is established that the normal congruent deposition of Ni81Fe19 alloy films takes place and abnormal codeposition is excluded.

Синтез 5-арил-4-ацил-3-гидрокси-1- карбоксиметил-3-пирролин-2-онов

5-Aryl-1,4-disubstituted terahydropyrrole-2,3-diones are five-membered nitrogen heterocycles containing in the first alkyl position or an aryl functionalized substituent and in the fourth position in another state of nature an acyl residue. Trahydropyrrole-2,3-diones constitute a significant class of available and stable substances. Along with this, they easily enter into reactions with various nucleophilic reagents due to the highly reactive carbonyl group in the third position of the heterocycle. The presence of the latter, as well as the carbonyl group of the side chain, makes it possible to form various condensed systems from heterocycles in reactions with binucleophilic reagents. The synthesis of biologically active substances based on 1,4,5-trisubstituted tetrahydropyrrole-2,3-diones is one of the promising ways of using this class of compounds. Previously, it was found that 1,4,5-trisubstituted 3-hydroxy-3-pyrin-2-ones have anti-inflammatory, analgesic, antimicrobial, nootropic, antiplatelet and antiviral activity. We set the task to obtain 5-aryl-4-acyl-3-hydroxy-3-pyrrolin-2-ones, in the first position of the heterocycle there is a carboxymethyl substituent. By setting up a three-component reaction of acylpyruvic acid ether with aromatic aldehydes and glycine in dioxane in dioxane. The structure of the compound was established on the basis of IR and 1H NMR spectroscopy data. Based on the data of 1H NMR spectroscopy and a positive reaction with an alcoholic solution of iron(III) chloride, the predominant presence of compounds in the enol form was established. The article presents the proposed mechanism and schemes of the formula for the synthesis of 5-aryl-4-acyl-3-hydroxy-1-carboxymethyl-3-pyrrolin-2-ones, their physicochemical and spectral characteristics, as well as the yields of the reaction products.

Galvanic Corrosion Behavior between Aluminum and Iron in Chloride Solutions at Near-Neutral pH and Corrosion Prevention By Anodizing

The joints between steels and aluminum alloys are expected to be used as multi-material structures due to their low cost, high stiffness, and high corrosion resistance. When aluminum alloys are connected to steels, galvanic corrosion is expected to occur because the corrosion potentials of aluminum alloys are lower than those of iron and steels. In the case of the galvanic corrosion in chloride solutions at near-neutral pH, the anodic reaction on aluminum alloys are oxide film formation and/or pitting. For pure Al and aluminum alloys, the generation of localized corrosion is evaluated by the critical potential for localized corrosion, such as pitting potential. In this study, the electrode potential under galvanic coupling and pitting potential were compared. Surface modification is effective methods for improvement on corrosion resistance of aluminum alloys. However, there is little research related to the galvanic corrosion between steels and aluminum alloys. In this research, the galvanic corrosion behavior of pure aluminum coupled to pure iron in chloride containing near-neutral pH solutions and the effect of anodizing on galvanic corrosion were investigated.Pure iron and pure aluminum were prepared as specimens in this research. The specimen surface of aluminum was polished down to 0.25 µm with a diamond paste. The iron surface was also polished down to 1 µm with a diamond paste. Diluted synthetic seawater (200 mg/L Cl-, pH 8.2) was used as the electrolyte for electrochemical measurements. The electrode area was ca. 10 mm2. Ag/AgCl (3.33 M KCl) was used as the reference electrode. Galvanic currents and electrode potentials were measured. The distance between iron and aluminum electrodes was kept at 10 mm. A zero resistance ammeter was used to measure the galvanic currents. The electrode potential of pure aluminum was also measured. Additionally, anodizing in sulfuric acid was conducted to pure aluminum in various voltages and times. Galvanic current measurements were carried out between these anodized specimens and pure iron to evaluate the effect of anodizing on galvanic corrosion prevention.The galvanic currents and electrode potentials of pure aluminum coupled to pure iron were measured. The galvanic currents were anodic currents. The oscillations of galvanic currents and electrode potentials were generated during the measurements. Filiform corrosion was observed on pure aluminum after the measurements. The generation of filiform corrosion was caused by higher electrode potentials of pure aluminum coupled to pure iron compared with the initiate potential for filiform corrosion.The time variation of galvanic currents and electrode potentials of anodized aluminum coupled to pure iron were also measured in the diluted synthetic seawater (pH 8.2). Pure aluminum specimens were anodized at 4, 8 and 16 V at 18 s. The oscillations were observed in the galvanic currents of anodized aluminum (4 and 8V); however, no oscillation was measured on the specimen anodized at 16 V. After the measurements, pitting was observed on anodized aluminum (4 and 8V). However, no pitting was observed on the specimen anodized at 16 V. The thickness of anodic oxide film was measured. It was confirmed that the thickness of the oxide film increased with anodizing voltage. Consequently, it was indicated that the galvanic corrosion resistance of pure aluminum for galvanic corrosion was enhanced by the increase of the thickness of the oxide film.

Синтез и свойства 1-аминокарбонилметил-5-арил- 4-ароил-3-гидрокси-3-пирролин-2-онов

3-Hydroxy-3-pyrrolin-2-ones are fully hydrogenated heterocyclic compounds, the base of which is included in a number of biologically active substances and drugs. Scientists' interest in 3-Hydroxy-3-pyrrolin-2-ones is due to the fact that, with their availability and high stability, they also have high reactivity due to the active carbonyl group in the third position of the heterocycle and easily interact with moconucleophiles. In addition, the presence of acyl and ethoxycarbonyl groups in the fourth position of the heterocycle makes it possible to obtain various condensed systems in reactions with binucleophiles, thereby making it possible to expand the range of the indicated compounds. We set the task to prepare 5-aryl-4-acyl-3-hydroxy-3-pyrrolin-2-ones containing an amino-carbonylmethyl substituent in the first position of the heterocycle, which were not previously described in the literature. It was also supposed to establish how the obtained compounds react with hydrazine hydrate. A series of 1-aminocarbonylmethyl-5-aryl-4-aroyl-3-hydroxy-3-pyrrolin-2-ones was obtained by setting up a three-component reaction of aroylpyruvic acid methyl ester with aromatic aldehydes and glycinamide hydrochloride in glacial acetic acid. The structure of the obtained compounds was established on the basis of IR and 1H NMR spectroscopy data. Based on the data of 1H NMR spectroscopy and a positive reaction with an alcoholic solution of iron(III) chloride, the predominant existence of the obtained compounds in the enol form was established. The article describes the mechanism of three-component reactions, the structural formulas of the obtained compounds, their physicochemical properties and spectral characteristics, as well as the yields of the reaction products. We have also studied the interaction of 1-substituted 5-aryl-4-acyl-3-hydroxy-3-pyrrolin- 2-ones with such a binucleophilic reagent as hydrazine hydrate. As a result of refluxing 1-amino-carbonylmethyl-3-hydroxy-4-(4-methoxybenzoyl)-5-(2-chlorophenyl)-3-pyrrolin-2-one and hydrazine hydrate in glacial acetic acid, 2-[4-(2-chlorophenyl)-3-(4-methoxyphenyl)-6-oxo-4,6-dihydropyrrolo [3,4-c] pyrazol-5(1H)-yl] acetamide. The article describes the proposed reaction mechanism, product yield, its physicochemical properties and spectral characteristics.

Reducing the Competition: A Dual-Purpose Ionic Liquid for the Extraction of Gallium from Iron Chloride Solutions.

The separation of gallium from iron by solvent extraction from chloride media is challenging because the anionic chloridometalates, FeCl4− and GaCl4−, display similar chemical properties. However, we report here that the selective separation of gallium from iron in HCl solution can be achieved using the dual-purpose ionic liquid methyltrioctylammonium iodide in a solvent extraction process. In this case, the reduction of Fe3+ to Fe2+ by the iodide counterion was found to inhibit Fe transport, facilitating quantitative Ga extraction by the ionic liquid with minimal Fe extraction from 2 M HCl.

Synthesis of nanospindle-akaganéite and its photocatalytic degradation for methyl orange.

Iron oxyhydroxides as important catalysts and environmental mineral materials have drawn significant interest for their potential applications in the field of wastewater treatment. In this work, we investigated the influence of nonionic surfactant Brij30 or glucose (0.01 wt%) on the formation of iron precipitates in iron(III) chloride solutions for 3 days at 40, 60 and 80 °C. The results showed that the presence of glucose or Brij30 could promote the nanospindle-akaganéite formation and the akaganéite with a length of 300-500 nm obtained at 60 °C was the optimal catalyst for organic photocatalysis degradation. Further, we investigated the capacity of C60 akaganéite for degradation removal of methyl orange (MO) under the action of hydrogen peroxide (H2O2) addition and/or UV irradiation, and in the presence of different radical scavengers at pH 4.5. We also researched the effects of various levels of H2O2 and catalyst, and the reaction pH values. It was found that akaganéites could remove almost 100% of MO under 100 mg·L-1 of catalyst and H2O2 at pH 4.5. Akaganéite maintained 86% of MO removal capacity after four successive cycles. Our results can be used as a reference for the synthesis of environmentally functional material and the application in photocatalytic degradation of organic pollutant.

Immobilization of dopamine on the copolymer of N‐vinyl‐2‐pyrrolidone and allyl glycidyl ether and synthesis of new hydrogels

AbstractAn epoxy‐containing copolymer was synthesized by radical copolymerization of N‐vinyl‐2‐pyrrolidone and allyl glycidyl ether. Further, the obtained copolymer was used to immobilize dopamine. It was found that immobilization of dopamine follows an equation of second general order and is accompanied by opening of the epoxy cycle. The synthesized dopamine‐containing copolymer was used to produce hydrogels that are formed during the treatment thereof with solutions of iron(III) chloride and sodium periodate. The gel formed upon treatment with iron(III) chloride was found to be pH sensitive. It was shown that the hydrogel obtained through oxidation with sodium periodate is capable of complete slow degradation in a saline phosphate buffer at pH 7.5. © 2020 Society of Chemical Industry

Recycling of blast-furnace sludge by thermochemical treatment with spent iron(II) chloride solution from steel pickling

One of the typical wastes produced in blast-furnace (BF) ironmaking is BF sludge, which mostly consists of carbon and iron oxides, but also contains toxic trace metals such as Zn, Pb, Cd, As, and Hg that render the material hazardous. Due to the lack of an established recycling process, BF sludges are landfilled, which is ecologically questionable and costly. Here, we investigate selective removal of Zn, Pb, and Cd from BF sludge by chlorination–evaporation reactions using thermodynamic modelling and laboratory-scale experiments. Specifically, BF sludge was thermochemically treated at 650–1000 °C with a spent iron(II) chloride solution from steel pickling and the effects of process temperature and retention time on removal of Zn, Pb, and Cd were investigated. Zinc and Pb were quantitatively removed from BF sludge thermochemically treated at 900–1000 °C, whereas Fe and C as well as other major elements were mostly retained. The Zn, Pb, and Cd contents in the thermochemically treated BF sludge could be lowered from ∼56 g/kg, ∼4 g/kg, and ∼0.02 g/kg to ≤0.7 g/kg, ≤0.02 g/kg, and ≤0.008 g/kg, respectively, thus rendering the processed mineral residue a non-hazardous raw material that may be re-utilized in the blast furnace or on the sinter band.