Ferric Chloride Solution Research Articles

Fabrication of a High-Strength, Tough, Swelling-Resistant, Conductive Hydrogel via Ion Cross-Linking, Directional Freeze-Drying, and Rehydration.

Conductive hydrogels have been in huge demand in biomedical and wearable electronics. However, the application of traditional conductive hydrogels is largely limited due to their poor mechanical properties. Here, a conductive hydrogel with excellent mechanical strength and swelling resistance properties is prepared by ion cross-linking, directional freeze-drying, and rehydration. First, the acrylamide and acrylic acid are polymerized in the κ-carrageenan solution to form the hydrogel. Then, the obtained hydrogel is cross-linked with Fe3+ by soaking in ferric chloride solution. Finally, the ionic cross-linked hydrogels are reinforced by directional freeze-drying and rehydration. The resulting hydrogel has excellent tensile strength (5.67 MPa) and high toughness (7.63 MJ/m3). It is worth noting that the hydrogel also had excellent anti-swelling properties. Its mechanical strength and volume almost show no changes after soaking in deionized water for 40 days. In addition, the hydrogel exhibits good ionic conductivity (0.091 S/m), high sensitivity, and excellent stability when applied as a strain sensor. This work proposes a simple method to fabricate a conductive hydrogel with great mechanical properties and swelling resistance, which displays huge potential in varied fields.

Investigating the leaching performance of ferric chloride solution for metallic alloys resulting from reduction smelting of spent lithium-ion batteries

Smelting reduction of spent lithium-ion batteries (LIBs) produces metallic alloys containing Co, Ni, Cu, Mn, and Fe. Finding suitable reagents in terms of efficiency, economics, and friendly environment for the dissolution of these metals from the alloys is very important for the recovery process of the metals. In this work, the employment of ferric chloride solution for the dissolution of the metals from the alloys was studied. The effect of parameters like FeCl3 concentration, temperature, time, and pulp density on the leaching efficiency of metals was investigated. Our results indicate that ferric ions in the leaching solutions act as oxidizing agents for the dissolution of the metals, while chloride anions as ligands for the formation of the complexes of the dissolved metal ions. The best conditions for the dissolution of full metals were 0.7 mol/L FeCl3, 12.5 g/L pulp density, 22oC, and 30 min. In comparison with HCl or H2SO4 leaching agents, ferric chloride shows some advantages like a decrease in the dosage of acids and oxidizing agents, fast reaction kinetics, and low energy consumption. With its advantages, ferric chloride solution is considered a potential leaching agent in the recovery process of valuable metals from spent LIBs.

An invertebrate model in examining the effect of acute ferric iron exposure on proprioceptive neurons

Iron is an essential element for plant and animal life and is found in soil, fresh waters and marine waters. The Fe3+ ion is a vital prosthetic group and cofactor to mitochondrial electron transport complexes and numerous proteins involved in normal functioning. Despite its importance to life-sustaining processes, overexposure results in toxicity. For example, ferric iron (Fe3+) accumulation in the mammalian central nervous system is associated with various neurological disorders. Although current literature addresses the long-term effects of Fe3+ overload, fewer studies exist examining the effects of acute exposure. Using the blue crab (Callinectes sapidus), we investigate the effects of acute Fe3+ overload on proprioception within the propodite-dactylopodite (PD) nerve. For proprioceptive studies, 10- and 20-mM ferric chloride and ferric ammonium citrate solutions were used at 5- and 20- min exposure times. Exposure to 20 mM concentrations of ferric chloride and ferric ammonium citrate reduced excitability in proprioceptive neurons. Thus, Fe3+ likely blocks stretch-activated channels or voltage-gated Na+ channels. The depressive effects of Fe3+ are partly reversible following saline washout, indicating cells are not acutely damaged. Gadolinium (GdCl3, 1 and 10 mM) was used to examine the effects of an additional trivalent ion comparator. Gd3+ depressed PD nerve compound action potential amplitude while increasing the compound action potential duration. This study is relevant in demonstrating the dose-dependent effects of acute Fe3+ and Gd3+ exposure on proprioception and provides a model system to further investigate the mechanisms by which metals act on the nervous system.

Bacterial quality of urinary tract in patients with alkaptonuria

BackgroundThe aim of the current study was to determine whether there is an association between alkaptonuria (AKU) and urinary tract infection (UTI) by exploring the bacterial quality of the urinary tract, as most of the patients with AKU present with frequent occurrence of urinary tract symptoms such as incomplete emptying of urinary bladder, dysuria and nocturia. MethodsStudy samples were collected from 22 participants; 9 from patients with AKU, 9 from individuals who were AKU carriers, and 4 people served as control. Confirmation of AKU diagnosis was established by the ferric chloride test and quantitative determination of urinary homogentisic acid (HGA) levels. ResultsIn the ferric chloride test, the urine samples of AKU patients showed a characteristic black ring upon addition of few drops of ferric chloride solution. During urinary HGA determination, patients with AKU had increased levels of urinary HGA as compared to carriers and controls. The following 10 bacterial species were isolated from the urinary tract of AKU patients, carriers and controls: Sphingomonas paucimobilis, Escherichia coli, Francisella tularensis, Staphylococcus hominis, Staphylococcus haemolyticus, Leuconostoc mesenteroides, Dermacoccus nishinomiyaensis, Kytococcus sedentarius, Serratia fonticola and Granulicatella adiacens. The presence of S. paucimobilis was found in three male patients, and one female each from the carrier and control groups. Almost all study samples were positive for D. nishinomiyaensis and K. sedentarius. S. fonticola and G. adiacens were found only in AKU carrier females. ConclusionsThe results deduced that males show symptoms of arthritis early and more severely than females and by this it appears that there is an association between these symptoms and the percentage of bacterial infection in males that requires more accurate diagnosis and treatment to clarify such relationship. In the current study, males (patients, carriers, and controls) were more likely to have bacterial infections than females (64% vs. 36%). The 16 and 2 bacterial isolates, detected in 7 males and 2 females AKU patients, respectively, revealed that male AKU patients had a 2.3-fold greater rate of bacterial infection than female AKU patients. Therefore, further studies are warranted to investigate if there's any relationship between higher incidence of bacterial infections and development of AKU-related clinical symptoms in the male population.

The effect of tartrate on the mild leaching of low-grade polymetallic complex chalcopyrite ore in acidic ferric chloride solution

The mild leaching of low-grade polymetallic complex chalcopyrite ore (LPCCO) is of great significance, but is limited by the passive film.

Investigating cotton dyeing using exotic wood waste sawdust

Investigating cotton dyeing using exotic wood sawdust. The study investigated the possibility of using extracts from various species of exotic wood, obtained from waste sawdust, for dyeing cotton fabrics. Material from Obeche, Iroko, Merbau, Apple tree, American walnut, Tulip tree, Cumaru and Rosewood were used for the tests. Solutions of oxalic acid, tin chloride, aluminum sulfate and ferric chloride were used as mordants, along with no-mordant tests. The color was determined in the CIE L*a*b* coordinate system. Color fastness was tested using n-hexane for dry cleaning and acidic, alkaline and hydrogen peroxide bleach solutions. The results showed a strong dependence on the type of wood, the mortar used and the washing agent and covered a wide spectrum of color intensity and fastness. The best results were obtained for Rosewood, Merbau and Apple trees, while Tulip tree and American walnut turned out to be practically useless. Among the mordants used, the most intense colors were produced by metal salts, including ferric chloride, which strongly darkened fabrics. Dry cleaning proved to be the mildest of those tested, with the least effect on color fading.

Recovery of Sugar and Nutrients from Algae and Colocasia esculenta (Taro) Leaves Using Chemical Hydrolysis

Algal biomass and Colocasia esculenta (Taro) leaves are available as waste biomass all over India. These biomasses can be used as renewable and sustainable resources for sugars and nutrients. Recovered nutrients and sugars can be used as cheap raw materials for biofuels and biomaterials production. The hydrolysis of dried algal biomass and Colocasia esculenta (Taro) leaves were investigated using 1%, 2%, and 5% solutions of ferric-chloride, nitric acid, and acetic acid for the reaction times of 30 and 60 min at 121 °C and 103.4 kPa (15 psi). 1% and 2% H2SO4 treatments were used as the reference. The solid: liquid ratio was kept at 1:10 for all the experiments. For algal biomass, a 5% acetic acid treatment for 60 min was found to be optimum with a total carbohydrate release of 44.2 mg/g biomass (solubilized monomers-0.82 mg/g of biomass) and N and P solubilization of 1.8 mg total nitrogen/g biomass and 7 mg total phosphorus/g biomass. Moreover, for Colocasia esculenta (Taro) leaves, the maximum carbohydrate yield of 95 mg/g biomass (solubilized monomers-43.6 mg/g of biomass) and nutrient solubilization of 5.02 mg total nitrogen/g biomass was obtained with 5% ferric chloride treatment for 60 min. The results obtained showed that various hydrolyzing agents used in this study acted differently on different types of biomasses. Acetic acid worked best in hydrolyzing the algal biomass, and for the hydrolysis of Taro leaves, ferric chloride and nitric acid were effective. Statistical analysis showed that the chemical concentration was one of the prime factors for releasing P from algal biomass. For carbohydrate release from Taro leaves, either time or concentration, or both, were the prime factors that affected the carbohydrate release.

An extensive XPS analysis on sensitized PBDB-T-SF thin films for photovoltaic applications

A new investigation on the elemental composition and optical properties stability of PBDB-T-SF thin films was performed before and after chemical sensitization by immersion in nitromethane ferric chloride (FeCl 3 ) solution, in order to extend its photovoltaic potential. The paper presents the effect of ferric chloride on PBDB-T-SF thin films (90 ± 5 nm thickness) deposited on glass by spin coating. The optical properties changes were identified by spectrophotometry, simulated and modeled by spectroscopic ellipsometry, remarking a decrease in absorption coefficient, refractive index and extinction coefficient of the individual polymer thin film. The X-ray photoelectron spectroscopy (XPS) analysis shows the changes in terms of elemental composition. Additionally, related to the electrical properties, the study brings clarifications on the unusual increase of resistivity once the film is exposed to light, due to the attachment of iron ions to polymeric chains and to the existence of an iron oxide thin film on the top of polymer layer. These findings contribute to the understanding of the behavior of emerging fluorinated polymers, before and after chemical treatments and exposure to light. • Elemental composition and optical properties stability of PBDB-T-SF thin films • Complementarities between optical analysis and electrical measurements • Different photoconduction behavior of sensitized polymer thin films

Characterization of Fe0@Chitosan/Cellulose structure as effective green adsorbent for methyl Parathion, malachite Green, and levofloxacin Removal: Experimental and theoretical studies

The green hybrid structure of zerovalent iron decorated chitosan/cellulose substrate (Fe0@CH/CF) was synthesized based on sugarcane bagasse. The synthesis procedures involved the isolation of cellulose by acid/alkaline washing followed by simple mixing of cellulose fractions with a chitosan solution. The formed chitosan/cellulose particles were decorated with zerovalent iron by the precipitation of iron from ferric chloride solution (3 M) using the green reducing extract of khaya senegalensis leaves. The product was studied as an adsorbent for levofloxacin, methyl parathion, and malachite green dye in batch adsorption tests. The Fe0@CH/CF achieved saturation adsorption quantities (103.08 mg/g (levofloxacin), 237.8 mg/g (methyl parathion), and 166.5 mg/g (malachite green)) higher than its components. The classic isotherm and kinetic properties of the uptake processes follow the assumptions of the Langmuir and pseudo-first order models, respectively. An advanced monolayer model with one energy was used to illustrate the equilibrium and adsorption mechanisms. Based on the steric parameters, the Fe0@CH/CF can adsorb two to three of levofloxacin (n = 2.92) and methyl parathion (n = 2.57) and up to four molecules of malachite green dye (n = 3.01) per site. The adsorbent shows high active adsorption site density for methyl parathion (107.6 mg/g) as compared to malachite green (64.7 mg/g) and levofloxacin (37.9 mg/g). The Gaussian (levofloxacin (5.9 kJ/mol), methyl parathion (7.4 kJ/mol), and malachite green dye (7.7 kJ/mol)) and adsorption energies (levofloxacin (10.1 kJ/mol), methyl parathion (18.2 kJ/mol), and malachite green dye (10.8 kJ/mol) demonstrate the physisorption mechanisms. The thermodynamic functions reflect the spontaneous and endothermic properties of the reactions.

Effect of Zn2+ content in ferric chloride solution on the structure and lithium storage performance of α-Fe2O3-based anode materials prepared by a facile thermal decomposition method

Effect of Zn2+ content in ferric chloride solution on the structure and lithium storage performance of α-Fe2O3-based anode materials prepared by a facile thermal decomposition method

Quantitative 3D Characterization for Kinetics of Corrosion Initiation and Propagation in Additively Manufactured Austenitic Stainless Steel.

In situ X-ray computed tomography (X-ray CT) is used to investigate the effects of characteristic microstructural features on the pitting initiation and propagation in austenitic stainless steel specimens prepared with laser powder bed fusion (LPBF) additive manufacturing. In situ X-ray CT in probing the mechanism and kinetics of localized corrosion is demonstrated by immersing two LPBF specimens with different porosities in an aggressive ferric chloride solution for the evaluation of corrosion. X-ray CT images are acquired from the specimens after every 8hours of immersion over an extended period of time (216hours). Corrosion pit growth is then quantitatively analyzed with a data-constrained modeling method. The pitting growth mechanism of LPBF stainless steel is found to be different from that of conventional stainless steels. More specifically, the mechanism of corrosion pit initiation is closely correlated with the original lack of fusion porosity (LOF) distribution on the surface of the specimens and preferential pit propagation through the LOF pores inside the specimens. Pit growth kinetics are derived from pit volume changes determined through 3D data analysis. The pit growth kinetics in LPBF specimens are found to vary in the initial pit formation, competitive pit propagation, and the dominant pit growth stages.

Assessing the efficacy of non-destructive testing methods to detect pitting corrosion

ABSTRACT Calibration of the non-destructive testing (NDT) methods for pipeline inspections is commonly done via machined defects with simple shapes and known sizes. However, such defects do not represent, e.g. an actual pit morphology observed in the field, which could lead to the unreliable interpretation of the inspection results. This work proposed a systematic approach to create and characterise real pits in stainless steel pipe specimens to assess the sensitivity of selected NDT methods. Pipe samples with three different diameters and thicknesses were used. Pits of different geometries and dimensions were generated by electrochemical methods, and immersion in an acidic ferric chloride solution filled in pre-drilled holes on the external surface of the specimens. NDT methods including radiography, Eddy current and dye penetrant testing were used for detecting and sizing the pits. The results were then compared with true pit depths obtained from cross-section analysis. Radiography and Eddy current methods failed to detect small pits with depths less than 70 µm. The porous metal cover on the pit mouth affected the detectability of radiography, while it had little impact on Eddy current testing. The findings of this investigation could be used to design training and calibration blocks for NDT methods.

Evaluation of micro-metakaolin and ferric chloride solution in stabilising expansive soils

Expansive soils are generally characterised by their volume change when subjected to variation in water content. This may result in significant damage to supported and nearby structures. In this study, the swelling properties of bentonite material as an expansive soil are first determined. The expansive soil is then improved using two different approaches, namely, micro-metakaolin (Mm) and ferric chloride (FeCl3) solution. The optimum percentages for both additives are determined using laboratory experiments, which are 25 and 1% for the Mmand the ferric chloride solution, respectively. The free swell index of the bentonite after being treated with Mmand ferric chloride solution at the optimum percentages is found to decrease by about 54 and 62%, respectively. Meanwhile, the swelling pressure for the expansive soil decreased by 33 and 43% when mixed with the same optimum values of Mmand ferric chloride solution, respectively. On the basis of the results obtained in this study, the addition of ferric chloride solution achieved better results compared with Mm. This improvement technique may be used to enhance the properties of expansive soils that support different construction engineering projects.

In vitro cytotoxicity against breast cancer using biogenically synthesized gold and iron oxide nanoparticles derived from the hydroethanolic extract of Salvia officinalis L

Nanotechnology has a real-world impact on every aspect of life. Many researchers have been drawn to the biosynthesis of gold and iron oxide nanoparticles (Au-NPs and SPIONS) because they have a wide range of life applications. In this work, a single-step environmentally friendly biosynthesis of Au-NPs and SPIONS is reported by reducing solutions of gold aureate and ferric chloride is reported for the first time using the hydroethanolic extract (HEE) of Salvia officinalis (S. officinalis), an edible plant found in Egypt. The phytochemicals present in HEE were responsible for the reduction as well as stabilization of these nanoparticles. Before using the HEE, it was phytochemically screened for its constituents. Qualitatively, the HEE was found to have comparable levels of phenolics, flavonoids, tannins, proteins, carbohydrates, terpenoids, steroids, and polysaccharides. Quantitatively, total phenolics (236.91 ± 2.15 mg GAE/g extract), flavonoids (91.38 ± 0.97 mg QE/g extract), tannins (101.60 ± 1.33 mg/g extract), proteins (284.62 ± 2.65 mg/g extract), carbohydrates (127.73 ± 1.68 mg/g extract), soluble sugars (52.3 ± 0.67 mg/g extract), and polysaccharides (75.43 ± 1.01 mg/g extract) were estimated. In addition, HPLC analysis revealed the identification of seven phenolic compounds [ferulic (67.26%), chlorogenic (3.12%), caffeic (3.11%), p-coumaric (1.13%), protocatechuic (0.65%), catechin (0.69%), rosmarinic (0.53%)] and three flavonoids [apigenin (5.29%), quercetin-7-O-glucoside (3.39%), and luteolin-7-O-rutinose (2.01%)]. The characterization of the biosynthesized NPs was confirmed by Fourier transform infrared (FT-IR) spectroscopy, UV–Vis absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). In vitro cytotoxic studies showed that Au-NPs, SPIONS, and HEE have an inhibitory effect on the growth of human breast cancer (MCF-7) cells at an IC50 of 6.53, 6.97, and 26.12 µg mL−1, respectively, by comparison with the standard drug (Doxorubicin) effect (0.18 µg mL−1).

Stress corrosion cracking of 316L manufactured by laser powder bed fusion in 6% ferric chloride solution

The stress corrosion cracking (SCC) of 316L stainless steel manufactured by laser powder bed fusion (LPBF) was investigated by slow strain rate tests in 6 wt% FeCl3. The effects of build orientation and surface roughness on the SCC of LPBF 316L were also investigated. LBPF 316L revealed higher uniform elongation compared to wrought 316L. Specimens tested perpendicular to the build direction showed a greater susceptibility to SCC, with cracks propagating along melt pool boundaries with cellular dissolution. The ‘As-built’ LPBF 316 L specimens with higher surface roughness compared to machined (smooth-surfaced) LPBF 316L specimens, also revealed greater SCC susceptibility.

A facile strategy to fabricate phosphorus-free and halogen-free flame retardant polyacrylonitrile fiber based on amidoximation and Fe (III) ion chelation

In this work, we proposed a novel phosphorus-free and halogen-free strategy to prepare flame retardant polyacrylonitrile fibers (FR-PAN). First, PAN fibers were modified with hydroxylamine hydrochloride (HA) to introduce amidoxime groups in PAN fibers (A-PAN), then the A-PAN samples were immersed in ferric chloride solution to chelate Fe3+ to obtain FR-PAN. The micro calorimeter (MCC) test showed that the peak heat release rate (PHRR) and total heat release (THR) of FR-PAN were reduced by 72.9%, and 86.9% respectively. Meanwhile, the limiting oxygen index (LOI) value of FR-PAN increased from 17.0% to 36.7%. TG results demonstrated that amidoxime groups promoted the cyclization and dehydrogenation of PAN in advance. Meanwhile, the released nonflammable NH3 effectively diluted the emission of combustible gases, which acted as a flame retardant role in gas-phase. Fe3+ had synergistic catalytic char formation effect, resulting in a highly dense char layer containing Fe2O3, which isolated oxygen, significantly reduced the emission of toxic gases. This work endowed PAN fibers with good flame retardancy and great potential application in the field of functional fibers.

In Vitro Antioxidant, Cytotoxic, Thrombolytic Activities and Phytochemical Evaluation of Methanol Extract of the Ampelocissus Barbata (Wall.) Leaves

Context: Oxidative stress and pertaining counterbalance mechanism are actively working in the living organisms. The overproduction of reactive oxygen species (ROS) in the ongoing equipoising process requires to be compensated by strong antioxidants. Plants as a rich source of antioxidants not only reduce oxidative stress but also possess cytotoxic, thrombolytic and phytochemical potentials. Aims: To find out the antioxidant, cytotoxic, thrombolytic and phytochemical capabilities of the methanolic extracts of Ampelocissus barbata (Wall.) leaves. Methods and Material: Assessment of the in vitro antioxidant activity of extract was carried out using DPPH radical scavenging assay, determination of reducing power capacity and total phenolic content. The thrombolytic activity was assessed by disintegration of clot and prospective phytochemical activities were by standard qualitative analysis such as Mayer’s, Dragendroff’s Wagner’s and Hager’s Reagent test for alkaloids; Libermann-Burchared and Salkowski Reagent tests for steroid and terpenoids; Molish Reagent, Benedict’s Reagent, Fehling’s Solution A & B reagent test for carbohydrates; Ferric Chloride (5%) Solution, Potassium Dichromate (10%) Solution tests for tannins; Shinoda test and Alkaline reagent test for Flavonoids; Froth tests & Haemolysis test for Saponins. Statistical analysis used: The statistical analysis was carried out using GraphPad Prism and Microsoft excel Results: Appreciable DPPH radical scavenging activity of the extract was observed with the IC50 value of 107.47±1.46 µg/ml. A significant correlation was found between the standard ascorbic acid (AA) and the plant extracts at the p˂0.05 for the reducing power assay where, the activity increased with the concentration of the extracts and the highest absorbance value was 3.025±0.15 and 1.826±0.006 for the AA and the extracts respectively. The plant also accommodates a considerable amount of polyphenols, reflected in the value of gallic acid equivalent 277.397±0.419 mg/ml. Finally, the percentage (%) of clot lysis for the thrombolytic activity was revealed to be 7.031±0.697, 35.297±1.307, and 75.083±0.599 for the water (negative control), extract, and the standard Streptokinase respectively. The study revealed the presence of phytochemicals namely alkaloids, flavonoids, tannins and glycosides. Conclusions: The study disclosed the promising in vitro activity of the plant, which necessitates the further analysis for the isolation and evaluation of the active principles.

Degradation of Amido Black Dye Using Ultra-Violet Light Catalyzed by Iron Oxide Nanoparticles: Kinetics and Mechanism of Degradation

In this study, we investigated the degradation of amido black dye in an aqueous solution using ultra-violet (UV) light catalyzed by iron oxide nanoparticles (nano-Fe). The nano-Fe was synthesized by sodium borohydride reduction of ferric chloride solution and was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray fluorescence spectrophotometry (XRF). The SEM of the nano-Fe showed regular spherical particles, the XRD examination showed a weak and broad peak at Fe (1 1 0), and the XRF study showed that the element with the highest composition was Fe2O3 (60.80%). The degradation experiments showed that the UV light catalyzed by nano-Fe could effectively degrade amido black dye. The nano-Fe/UV system could degrade 5 mg/L of amido black dye up to 93.2% at 254 nm after being irradiated for 60 min. The nano-Fe/UV system could be described by the Langmuir–Hinshelwood kinetic model, and the rate constants (kapp) were 0.0183–0.0323 min−1. Thus, UV light combined with nano-Fe can be applied for the efficient remediation of dye wastewater.

THE SEDIMENTATION BEHAVIOURS OF AlPO4 AND Fe3(PO4)2 PRECIPITATES IN SOLUTIONS OF SODIUM CARBOXYMETHYLCELLULOSE AT DIFFERENT TEMPERATURES

To evaluate the sedimentation of aluminium phosphate [AlPO4] and ferrous phosphate [Fe3(PO4)2] precipitates in sodium carboxymethylcellulose (Na-CMC) biopolymer at different temperatures, batch-wise precipitation and sedimentation tests of AlPO4 and Fe3(PO4)2 in solutions of Na-CMC were carried out at temperatures of 30, 40 and 50oC. The objective was to determine On-set Sedimentation Rate (OSR) and Sedimentation Volume Ratio (SVR) of the metal phosphates. Fixed volume of Na-CMC at different concentrations was mixed with constant volume and known concentration of phosphate ion precursor (disodium hydrogen phosphate solution) in a sedimentation measurement apparatus - PreSed Meter. The resulting solution was mixed separately with constant volume and known concentration of either aluminium ion or iron (II) ion precursor (either aluminium chloride or ferrous chloride solution). The settling of the precipitate so formed was monitored and recorded. Blank sedimentation tests, without Na-CMC, were also run. For every measurement, On-set Sedimentation Rate (OSR) and Sedimentation Volume Ratio (SVR) of the precipitates were computed. It was observed that in the absence of Na-CMC, AlPO4 precipitate readily dissolved into the medium immediately after stirring. Also, in the absence of Na-CMC, OSR and SVR of Fe3(PO4)2 precipitate increased directly with increased temperatures. The test results also indicated that AlPO4 precipitate suspension was poorly influenced by the biopolymer. Poor correlations in OSR (0.50 ≤ R2 ≥ 0.05) and SVR (0.49 ≤ R2 ≥ 0.005) indicating non-dependence with Na-CMC concentration, implying no chemical interactions with Na-CMC, were described for AlPO4 suspension at all temperatures investigated. For Fe3(PO4)2 suspension, good correlations in OSR (R2 = 0.94) and SVR (R2 = 0.93) indicating dependence with Na-CMC concentration, implying chemical interaction with Na-CMC, were obtained at high temperature (50oC). The observations imply that Na-CMC would be good stabilizing agent for drug formulations containing AlPO4. However, suspension of Fe3(PO4)2 in Na-CMC need not be stored in high temperature conditions.

Novel approach to recycling of steel swarf using hydrometallurgy

Steel swarf is a hazardous waste which is challenging to recycle due to its high content of heavy metals and cutting fluids and is today commonly landfilled. The swarf can contain up to 80% iron and represents a potential secondary raw material for production of reagents like ferric chloride, which can be utilized in wastewater treatment. This work presents a novel hydrometallurgical approach for recycling steel swarf and production of ferric chloride by selective separation of iron from heavy metals. Swarf containing 69% iron was leached with hydrochloric acid. A leachate containing 24.600 mg/L Fe with 150 mg/L Mn, 12 mg/L Ni and <1 mg/L Cr and Mo was obtained. The oil-based cutting fluids largely remained in the solid residue with only 1% dissolution in the aqueous phase. These findings showed that ferric chloride solutions of 99% purity can be produced from steel swarf in a single leaching step.