Ferrous Concentration Research Articles

Removal of chloramphenicol in aqueous solutions by modified humic acid loaded with nanoscale zero-valent iron particles

As a natural organic carbon skeleton, humic acid (HA) was loaded with nanoscale zero-valent iron (nZVI) Particles to remove chloramphenicol (CAP) from aqueous solution. The pore morphology and structure, the type, the distribution and valence state of element, and the class of functional groups on the surface of the material were shown by SEM/EDS, XPS, BET and FTIR. When the load ratio of nZVI on HA was 1:30, the iron content in the material was minimized, the specific gravity of the economic material-HA was increased, and the removal efficiency of CAP was 80.0% or higher. In addition, the mass ratio of nZVI on HA, the dosage of nZVI/HA-30, the initial pH and CAP concentration of the solution, these four general factors, played an important role in the efficiency and equilibrium time of the CAP removal. The removal efficiency of CAP by nZVI/HA-30 was 84.2% when the dosage was 1.0 g (100 mL)−1, the initial concentration of CAP was 30 mg L−1 and the pH was 3. The reaction pathway and removal mechanism of ZVI/HA-30 were studied by the concentration of total and ferrous iron ions in the solution, UV–Vis and MS. The CAP was continuously denitrified and dechlorinated, decomposed into easily degradable substances by nZVI particles supported on HA, which was consistent with the first-order kinetic model within 5 min. This newly synthesized material was economical and efficient, easy to store, effectively prevented agglomeration and passivation of nZVI, and had a good application prospect for removing contaminants from water.

A turn-on/off fluorescent sensor based on nano-structured Mg-Al layered double hydroxide intercalated with salicylic acid for monitoring of ferric ion in human serum samples

The present work aimed to provide a novel chemosensor for ferric ion detection in human serum samples using nano-structured Mg-Al layered double hydroxide intercalated with salicylic acid (Mg-Al LDH–SA) as a sensitive fluorescence probe. The Mg-Al LDH–SA nanomaterial was synthesized and characterized via Fourier transform infrared spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, dynamic light scattering and energy dispersive spectroscopy. The synthesized nanomaterial was applied to determine ferric ions by measuring the fluorescence intensity of Mg-Al LDH–SA sol solution at λem = 404 nm with excitation at λex = 287 nm. In the presence of ferric ions, the fluorescence intensity decreases owing to the formation of a stable complex between ferric ions and salicylic acid. Several important parameters affecting the analytical signal were studied and optimized. Under optimum conditions, the calibration graph was linear in the concentration range of 0.07–100 μmol L−1 with a corresponding detection limit of 26 nmol L−1. The intra- and inter-day relative standard deviations (n = 6 and ferric ion concentration; 50 μmol L−1) were 3.4% and 4.5%, respectively. The method was successfully employed to assess ferric ion in several human serum samples with relative recovery values between 98.7 and 104.6% for the spiked samples.

Employing Sono-Fenton Process for Degradation of 2-Nitrophenol in Aqueous Environment Using Box–Behnken Design Method and Kinetic Study

Removal of 2-nitrophenol (2NP) from aqueous solution was performed using Sono-Fenton process. The Box–Behnken design (BBD) of experiments was used to investigate the influence of operational factors such as pH, initial concentration of hydrogen peroxide and ferrous ions on the removal of 2NP. The ANOVA (analysis of variance) showed a satisfactory prediction second-order regression model and a high determination coefficient value. The optimum conditions predicted by the model were as follows: the [Fe2+] = 10 mg/L, pH 3, and [H2O2] = 475 mg/L. The results showed that at the predicted optimum conditions and after 60 min of reaction, the degradation of 70 mg/L of 2NP and its corresponding Chemical oxygen demand (COD) was 97.8 and 76.5%, respectively. The kinetic study for mineralization of 2NP was investigated and the rate constants (K = 25.4 × 10–3 min–1) and half-life time of mineralization reaction ( $${{t}_{{1/2}}}$$ = 27.28 min) were achieved.

Basics of the Metallic Corrosion in Crude Oils

Corrosion is an often-used term regarding the ferrous metals also the general phenomenon of the formation of metal oxides, sulfides, hydroxides or any certain compound on the metal surface itself. There were found the effect of corrosive compounds in crude oils on the metallic corrosion in most of researches up to certain stage. In the current research it was expected to speculate the effect of sulfur, mercaptans, organic acids and salts in both Murban and Das Blend crude oils on the corrosion rates of seven different types of ferrous metals and variations of the hardness of such metals. The corrosive properties of both crude oils were determined by the standard methods and instruments. The chemical compositions of metals were detected by XRF detector. A batch of similar sized metal coupons was prepared, and those metal coupons were immersed in both crude oils separately. The rates of corrosion of those metal coupons were determined by the weight loss method after 15, 30 and 45 days from the immersion also both initial hardness and hardness after corroded of each metal coupon were tested by Vicker’s hardness tester. The corroded surfaces were observed by the optical microscope also the ferrous concentration and copper concentration of each crude oil sample were measured by the atomic absorption spectroscopy (AAS) after exposed to metals. There were found relatively lower corrosion rates from stainless steels than other metals, higher corrosion rates of four types of metals in Murban crude oil although it was composed lower amount of sulfur, mercaptans, organic acids and higher amount of salts than Das Blend, higher ferrous concentrations in crude oil samples which were exposed to carbon steels than other crude oil samples whereas high concentrations of copper in crude oil samples relevant to the Monel metal and eventually it was a slight reduction of the initial hardness of each metal coupon due to the corrosion.

Corrosion Behavior of X65 Carbon Steel in CO2Containing Liquids with Constant pH and Ferrous Ion Concentration

Corrosion Behavior of X65 Carbon Steel in CO2Containing Liquids with Constant pH and Ferrous Ion Concentration

Removal of iron as oxyhydroxide (FeOOH) from aqueous solution by fluidized-bed homogeneous crystallization

Abstract In this study, iron is removed from aqueous solution using a fluidized-bed crystallizer. Homogeneous oxyhydroxide pellets (FeOOH) were recovered at various value of pH, surface loading (L), and initial ferrous concentration to assess the treatability of iron-containing water. The optimal conditions for treating initial ferrous concentrations of 100–300 mg/L were L = 0.6 kg/m2/h (with 29 m/h of upflow velocity), a bed expansion of 50% and pH = 6.5 yielding the total iron removal (TR) of more than 99% and a corresponding iron crystallization ratio (CR) of 85%. X-ray diffractometry (XRD) revealed that the pellets consisted of a mixture of goethite (α-FeOOH) and lepidocrocite (γ-FeOOH). Scanning electron microscopy (SEM) yielded images of pellets of up to 1 mm in diameter, which were assembled from FeOOH flakes with thicknessess of 0.2–0.4 µm.

Improved organic pollutants removal and simultaneous electricity production via integrating Fenton process and dual rotating disk photocatalytic fuel cell system using bamboo charcoal cathode

A coupling system combining Fenton process with dual rotating disk photocatalytic fuel cell (PFC) was developed to improve methyl orange (MO) removal and simultaneous electricity production, in which the (NH4)3PO4 modified bamboo charcoal (BC) was acted as cathode catalyst. Due to the existence of the N and P containing functional groups on the BC catalyst and the rotating electrode, the hybrid system could efficiently reduce oxygen to generate some hydroxyl radical and related species for MO removal. Therefore, Fenton-PFC-BC with rotation system showed a superior MO removal efficiency of 85%, 2.4 times higher than that in the traditional Fenton-PFC-Pt with aeration system. The radicals inhibition assays and hydrogen peroxide quantitative studies revealed that HO, h+ and O2− were primarily responsible for MO degradation. Furthermore, the MO removal performance for Fenton-PFC-BC with rotation system was investigated at different parameters (such as rotating speed, BC loading, pH and ferrous ion concentration) to obtain optimal operation conditions. Results of energy analysis and reusability experiment showed that the proposed Fenton-PFC-BC with rotation system provided a cost-effective and stable method for the organic degradation and energy recovery.

The Investigation of the Primary Corrosiveness of Crude Oils

Crude oil is a mixture of hydrocarbons with some kinds of trace compounds including corrosive causing compounds. Corrosion is a severe consequence regarding the industry of crude oil refining. The scope of this research was to investigate the contributions of corrosive properties of both Murban and Das Blend crude oils on the corrosion rates of seven different types of ferrous metals which are obligatory in the crude oil refining industry. The sulfur contents, Mercaptans contents, organic acid contents and salt contents of both crude oils were tested by following the standard methodologies and recommended instruments. The elemental composition of each metal coupon was tested by the XRF detector. A batch of similar sized metal coupons was prepared and those metal coupons were immersed separately in both crude oils in homogeneous way. After 15, 30 and 45 days from the immersion the corrosion rates of each type of metal were determined by the relative weight loss method with the aid of a microscopic analysis. The decayed ferrous and copper concentrations in crude oil samples were tested by the atomic absorption spectroscopy (AAS) and the variations of the initial hardness of such metal coupons due to the corrosion were tested as confirmation stages of the formation of the corrosion. There were found some relatively lower corrosion rates from stainless steels with respect to both crude oils among other metals, higher corrosive impact from salts formations of FeS, Fe2O3 and some different trace compounds, higher ferrous and copper concentrations in some of crude oil samples and slight reductions of the initial hardness of most of metal coupons due to the corrosion as the foremost results of the existing research.

Hiệu quả của chế phẩm hữu cơ vi sinh chứa bốn dòng vi khuẩn Rhodopseudomonas sp. đối với hấp thu đạm, nhôm và sắt trong hạt lúa trồng trên đất phèn huyện Phụng Hiệp, tỉnh Hậu Giang ở điều kiện nhà lưới

Acid sulfate soil (ASS) contains high aluminum and ferrous concentrations that might cause the reduction of nutrient uptake and an increase of toxic accumulation. Rhodopseudomonas sp. has ability to reduce aluminum and ferrous toxicity of ASS for rice cultivation. The objectiveof this research was to evaluate the efficacy of biofertilizers containing four acid-resistant R. palustris VNW64, VNS89, TLS06 and VNS02 on theaccumulation of nitrogen and toxic compounds in rice grains. A two factorial experiment was conducted in a randomized complete block design on ASS collected from Phung Hiep district, Hau Giang province under nethouse conditions. Therein, the first factor was biofertilizer application including four mixedbacterial strains, only VNW64 and no biofertilizer application. The second factor was inorganic N fertilizer application containing 0, 50, 75 and 100 kg N ha-1. The results showed that thetreatments applied either with biofertilizer containing four mixed bacterial strains or biofertilizer containing onlyVNW64 helped to increaseN uptake from39.7 to 49.2%, to reduce Al uptake from 18.4 to 30.4% and to reduce Fe uptake from 0.1 to 2.7% in rice. The biofertilizers containing a mixture of four strains or one bacterial strain showed their efficacy in enhancement of N uptake and reduction of Al and Fe accumulation in rice grains when cultivated on ASS.

Evaluation of Single Hydrogel Nanofiber Mechanics Using Persistence Length Analysis.

Polyelectrolyte hydrogel fibers can mimic the extracellular matrix and be used for tissue scaffolding. Mechanical properties of polyelectrolyte nanofibers are crucial in manipulating cell behavior, which metal ions have been found to enable tuning. While metal ions play an important role in manipulating the mechanical properties of the fibers, evaluating the mechanical properties of a single hydrated hydrogel fiber remains a challenging task and a more detailed understanding of how ions modulate the mechanical properties of individual polyelectrolyte polymers is still lacking. In this study, dark-field microscopy and persistence length analysis help directly evaluate fiber mechanics using electrospun fibers of poly(acrylic acid) (PAA), chitosan (CS), and ferric ions as a model system. By comparing the persistence length and estimated Young’s modulus of different nanofibers, we demonstrate that persistence length analysis is a viable approach to evaluate mechanical properties of hydrated fibers. Ferric ions were found to create shorter and stiffer nanofibers, with Young’s modulus estimated at a few kilopascals. Ferric ions, at low concentration, reduce the Young’s modulus of PAA and PAA/CS fibers through the interaction between ferric ions and carboxylate groups. Such interaction was further supported by nanoscale infrared spectroscopy studies of PAA and PAA/CS fibers with different concentrations of ferric ions.

Investigation of Chalcopyrite Leaching Using an Ore-on-a-Chip.

This paper reports on an ore-on-a-chip that enables efficient investigations of mineral leaching using real ore samples. Here, chalcopyrite (CuFeS2) ore samples are cut, polished flat, and sealed against a polydimethylsiloxane microchannel. The leach solution is collected for analysis, and the ore sample is then recovered for surface analysis. Compared to conventional bulk-scale leach tests, the ore-on-a-chip allows for faster, more efficient screening of leach parameters using real ore samples obtained from mine sites. Insight and optimization of leach conditions is demonstrated here for chalcopyrite, which has been extensively studied, yet leach performance is still strongly dependent on the origin of the ore. Two grades of chalcopyrite were chosen for this study (moderate and high purity), and the effect of ferric ion concentration and pH was studied in moderate and high purity chalcopyrite ores, respectively. The leach rate of Cu was faster in the presence of ore impurities (moderate grade) compared to the higher purity ore under the same conditions. The results also suggest that Fe is preferentially leached in the early stages to form an iron-deficient sulfide, according to X-ray photoelectron spectroscopy. Longer leach studies (48 h) reported no measurable surface passivation for the conditions studied. The ore-on-a-chip offers a new approach of case specific leach studies, which will enable rapid and tailored optimization of leach strategies for mineral processing.

Experimental Design Methodology Applied to the Degradation of a Cytostatic Agent the Imatinib Mesylate Using Fenton Process

This manuscript investigates the degradation efficiency of a cytostatic agent imatinib mesylate (IM) by Fenton process. The objective of the study is to determine the effect of initial concentrations of hydrogen peroxide, ferrous ion and IM on the degradation process of IM. In this context, the overall research is conducted in two stages. The first stage of experiments involves the evaluation of the experimental parameters impact on the IM removal using the factorial design; whereas the second one includes the optimization conditions for IM degradation using Doehlert design. Different concentrations of H2O2 (10–50 mmol L−1), Fe(II) (0.5–3 mmol L−1) and IM (0.045–1.7 mmol L−1) are adopted both to assess the main effects of factors and their interactions on the anticancer destruction and to establish the optimum process variables that ensure its total removal. The factorial matrix considering different combinations of factors and levels demonstrates that the concentrations of Fe(II) and IM are the most determining parameters on the removal of the target molecule. The Doehlert matrix reveals that the maximum IM abatement is predicted to be 100.59% (± 0.63) when the optimized reaction conditions are set at 30 mmol L−1 for H2O2 and 2.5 mmol L−1 for Fe(II).

Direct yellow degradation by combined Fenton-enzymatic process

Abstract The removal of direct yellow 106 (DY106, C.I.40300) by a combined process of Fenton oxidation and enzymatic degradation in a sequential or mixed batch reactor is discussed. Experiments were first conducted with the enzymatic and chemical oxidation processes separately in order to determine the effects of various parameters such as pH, ferrous ion, hydrogen peroxide, dye and enzyme concentrations on the overall yield and kinetics of both processes. Decolourization was followed by UV-visible spectroscopy and high performance liquid chromatography (HPLC). Results showed that 89.5 % of DY106 were removed by enzymatic treatment after only 2 min, while 10 min of contact time were necessary to eliminate more than 98 % of 50 mg/L by Fenton’s process. A high performance was achieved under optimized conditions by the mixed combined process with time reduction down to 5 min. The study was also conducted to evaluate the efficiency of combined Fenton’s reaction as a pre-treatment and post treatment process combined with C-peroxidase at different ferrous ions concentrations. The optimal doses of Fe2+ were 2.5 mM, 1m M and 0.8 mM for Fenton, Fenton-enzymatic sequential and mixed processes. Intermediate products absorbing in UV range were detected for single Fenton or enzymatic treatment but were eliminated in all combined enzymatic-Fenton processes. Phytotoxicity tests showed that no toxicity was detected after treatment by combined process.

A parameters study of the novel atmospheric pyrite oxidation process with Lewatit® AF 5 catalyst

A previous study conducted by the authors introduced a novel process for atmospheric pyrite oxidation with Lewatit® AF 5, a micro/mesoporous carbonaceous bead. This paper presents a parameters study of the atmospheric oxidation of the AF 5 catalysed pyrite oxidation process, promoting maximum pyrite oxidation and maximizing the elemental sulphur generation. Tests were conducted in 2 L jacketed reactors with controlled conditions. The study consisted of multiple tests investigating the effect of temperature (75, 80, 85 and 90 °C), initial sulphuric acid concentration (0.25, 0.5 and 1.0 M), initial ferric concentration (0, 1, 5 and 10 g/L), pyrite concentrate to catalyst mass ratio (4:1, 2:1, 1:1 and 1:2), and test slurry solid pulp density (5, 10 and 20 wt%) on the atmospheric leaching of a pyrite concentrate assisted by AF 5. The study indicated that the most effective parameters in the pyrite oxidation are the test temperature and concentrate to catalyst mass ratio. The best tests in terms of overall pyrite oxidation and elemental sulphur production were those with a 1:2 concentrate to catalyst ratio at 90 °C. These tests had an average of 96.2% overall pyrite oxidation and an elemental sulphur yield on average of 51.0%. Increasing temperature from 75 to 90 °C improved overall pyrite oxidation from 71.9 to 93.6%, however elemental sulphur yields of approximately 46.3% were experienced at temperatures below 90 °C versus 43.3% at 90 °C. Other trends experienced in the investigation of the various parameters will be further discussed.

Selective Colorimetric Detection of Fe (III) Using Metallochromic Tannin‐Impregnated Silica Strips

AbstractA solid state sensor tool used for determination of ferric ions (Fe+3) in an aqueous medium was developed using the environmental friendly tannin polyphenolic biomolecule as spectroscopic probe and silica plates as a host strip. The colorimetric recognition of the analyte is based on a tanna‐activated silica dipstick with a determination limit in the ppm level. The best detection of Fe (III) was accomplished in a pH range from 3.2 to 8.8. The metallochromic tannin‐impregnated silica diagnostic tool provided an instant color alteration from yellow to dark purple upon immersion in an aqueous environment of ferric cation as was demonstrated by the coloration measurements. This color shift is proportionally correlated with increasing the ferric concentration. Both qualitative and quantitative studies were performed. The sensor demonstrated high selectivity to Fe (III), while no color change was monitored for other metals. The recognition mechanism of ferric occurs via tannic (polyphenolic)‐Fe (III) polydentate complex creation. Different spectroscopic techniques, including scanning electron microscope, energy dispersive X‐ray spectroscopy as well as elemental mapping were utilized to characterize the tannic‐Fe (III) complex formation on the silica dipstick.

Chalcopyrite Bioleaching Using Adapted Mesophilic Microorganisms: Effects of Temperature, Pulp Density, and Initial Ferrous Concentrations

Chalcopyrite Bioleaching Using Adapted Mesophilic Microorganisms: Effects of Temperature, Pulp Density, and Initial Ferrous Concentrations

Chemical and microbial leaching of base metals from obsolete cell-phone printed circuit boards

Abstract Bioleaching process is recommended for the recovery of metals from electronic waste (E-waste) due to its environment-friendly nature and a rich source of metals present in the E-waste. Each gram of cell phone printed circuit boards (PCBs) powder used in the study contained 275.5, 17.85 and 19.55 mg copper, zinc and nickel as major metal constituents respectively. The chemical leaching by mixture of ferric sulphate and ferrous sulphate (70:30) at 100 g L−1 pulp density was best for copper leaching among the studied systems in which after 4 d of reaction time, 2740 mg copper was solubilized from cell phone PCB powder, while ferric sulphate alone was best for zinc and nickel solubilisation, in which 88 mg zinc and 135 mg nickel were solubilised after 4 d and 7 d of reaction time, respectively. Bioleaching study showed that with acidophilic iron oxidizers, pH 1.8 and initial ferrous concentration 9 g L−1 were optimum for Cu–Zn–Ni extraction from discarded cell phone PCB powder. Cu–Zn–Ni extractions from 10 g L−1 cell phone PCB powder pulp density by the metabolites of iron-oxidizing consortium were 275, 5 and 11 mg, while at 50 and 100 g L−1 pulp density, extractions were 1350, 18 and 53 mg, and 2640, 25 and 100 mg, respectively. The process can be further scaled-up for higher pulp density.

Enhancing ferrate(VI) oxidation process to remove blue 203 from wastewater utilizing MgO nanoparticles

The aim of this study is to investigate the beneficial effect of utilizing MgO nanoparticles on the performance of ferrate(VI) oxidation process to remove blue-203 dye from wastewater. It was also made an attempt to assess the effects of pH, temperature, and MgO nanoparticle dosage on this oxidation process performance. Several sets of batch experiment were conducted to find out the effects of temperature ranging from 25 to 65 °C, pH ranging from 1.5 to 13, ferrate(VI) concentration ranging from 0.5 to 5.9 mg/L and MgO nanoparticles dosage ranging from 0.01 to 0.05 g in 150 mL solution on the removal efficiency. The results showed that adding MgO nanoparticles can improve the performance of ferrate(VI) oxidation removal method significantly, spec. at basic conditions. This synergistic effect can be attributed to the simultaneous adsorption of ferrate(VI) and dye molecules on the surface of nanoparticles. The results also revealed that the reaction between blue-203 dye and ferrate(VI) takes place rapidly at high mixing rate. It means that the required time to complete the removal process is controlled by mixing rate. It was finally concluded that adding MgO nanoparticles was an efficient means to enhance the performance of ferrate(VI) to oxidize blue-203 dye, esp. under basic conditions.

Application of Sono\u2013photo-Fenton process for degradation of phenol derivatives in petrochemical wastewater using full factorial design of experiment

In this study, the degradation and mineralization of petrochemical wastewater containing phenol and nitrophenol with chemical oxygen demand (COD) at 260 mg/L and total organic carbon (TOC) at 100 mg/L, were investigated by Sono–photo-Fenton process. The full factorial design of experiment was used to explore the influence of operational variables such as pH, initial concentration of hydrogen peroxide and Ferrous ions on the removal of COD. The analysis of variance (ANOVA) showed a high determination coefficient value (R2 = 0.9884, R_{text{pred}}^{ 2} = 0.9713, R_{text{adj}}^{ 2} = 0.9822) for removal of COD and satisfactory prediction second-order regression model. The graphical response surface plots were employed to determine the optimum conditions. The operational variables were optimized by the model as follows: the [Fe2+] = 24 mg/L, pH at 3, and [H2O2] = 500 mg/L. The results showed that at the predicted optimum conditions and after 60 min of reaction, the degradation (removal of COD) and mineralization (removal of TOC) were 76.1 and 68.7%, respectively.

Portable and selective colorimetric film and digital image colorimetry for detection of iron

Iron is an important trace element in environmental and biological systems, the development of simple and selective methods for the determination of iron is important. In this work, completely biodegradable tapioca starch was introduced as the substrate to entrap standard chromogenic probes (1,10-phenanthroline) for fabrication of a novel colorimetric sensor for ferrous. A clear plasticized thin film from tapioca starch was fabricated inside a small plastic tube as a portable test kit. A red complex was obtained by exposing the film to a ferrous solution, while no color changes were obtained with various other ions, indicating excellent selectivity. The developed films were applied in conjunction with a digital image colorimetry for quantification of ferrous. Calculated molecular absorption of the red complex showed the widest linear range (0 to 10 mg L-1) with good linearity (R2 < 0.9934) with ferrous concentrations. The developed method provided good inter-day precision (1.75 to 3.97%RSD, 5 days 15 sensors), good accuracy (+2.35% to +4.57% relative error), and low detection limit (0.09 ± 0.01 mg L-1). The concentrations of ferrous ion in soil and water samples quantified by the developed method were not significantly different from atomic absorption spectrophotometry at 95% confidence level. The films were stable for at least three months.