Waste Iron Research Articles

Efficient phosphate removal from water using ductile cast iron waste: a response surface methodology approach.

Water scarcity is a critical issue worldwide. This study explores a novel method for addressing this issue by using ductile cast iron (DCI) solid waste as an adsorbent for phosphate ions, supporting the circular economy in water remediation. The solid waste was characterized using XRD, XRF, FTIR, and particle size distribution. Wastewater samples of different phosphate ion concentrations are prepared, and the solid waste is used as an adsorbent to adsorb phosphate ions using different adsorbent doses and process time. The removal percentage is attained through spectrophotometer analysis and experimental results are optimized to get the optimum conditions using Design Expert V13. The pseudo-second order (PSO) kinetics model and Langmuir isotherm were fitted with the experimental results with maximum adsorption capacity (qmax = 0.28mg/g). The thermodynamic analysis indicated that this adsorption process was spontaneous based on the negative value of Gibbs free energy (∆G). Additionally, the positive values of enthalpy (∆H) indicated the endothermic nature of this adsorption system. It was able to reach the highest adsorption percentage of 98.9 (%) for phosphate ions from aqueous solutions using response surface methodology (RSM) with optimum conditions of 10mg/L phosphate ion concentration, pH = 8, normal room temperature, 9min adsorption, and 0.5g/L adsorbent dosage.

Nutrient removal efficacy and microbial dynamics in constructed wetlands using Fe(III)-mineral substrates for low carbon-nitrogen ratio sewage treatment.

This study evaluated the roles of two common sources of Fe(III)-minerals-volcanic rock (VR) and synthetic banded iron formations from waste iron tailings (BIF-W)-in vertical flow-constructed wetlands (VFCWs). The evaluation was conducted in the absence of critical environmental factors, including Fe(II), Fe(III), and soil organic matter (SOM), using metagenomic analysis and integrated correlation networks to predict nitrogen removal pathways. Our findings revealed that Fe(III)-minerals enhanced metabolic activities and cellular processes related to carbohydrate decomposition, thereby increasing the average COD removal rates by 10.7% for VR and 5.90% for BIF-W. Notably, VR improved nitrogen removal by 1.70% and 5.40% compared to BIF-W and the control, respectively. Fe(III)-mineral amendment in bioreactors also improved the retention of denitrification and nitrification bacteria (phylum Proteobacteria) and anammox bacteria (phylum Planctomycetes), with increases of 3.60% and 3.20% using VR compared to BIF-W. Metagenomic functional predictionindicated that the nitrogen removal mechanisms in VFCWs with low C/N ratios involve simultaneous partial nitrification, ANAMMOX, and denitrification (SNAD). Network-based analyses and correlation pathways further suggest that the advantages of Fe(III)-minerals are manifested in the enhancement of denitrification microorganisms. Microbial communities may be activated by the functional dissolution of Fe(III)-minerals, which improves the stability of SOM or the conversion of Fe(III)/Fe(II). This study provides new insights into the functional roles of Fe(III)-minerals in VFCWs at the microbial community level, and provides a foundation for developing Fe-based SNAD enhancement technologies.

Electrosynthesis of ferrate from iron waste and seawater salts as Antibacterials for water pollutant treatment

The synthesis of ferrate from waste iron and seawater salt as antibacterial pollutants for Staphylococcus aureus and Escherichia coli in water treatment has been successfully carried out. The synthesis phases comprised the preparation of NaOCl from saltwater, Fe(OH)3 synthesis from iron waste, and the electrosynthesis of ferrate. The successful synthesis was confirmed by XRD at 30.05°, 36.87°, 40.51°, and 75.30° as Na2FeO4 (JCPDS file: 890169), the functional groups of FeO42- at 779 and 879 cm−1 in the FTIR spectrum. Moreover, it was also confirmed by the dominance of Fe and O element content in XRF and SEM-EDX, as well as the stability and ability to produce hydroxide radicals in Fluorescence analysis. Furthermore, tests of the antibacterial effectiveness were carried out with variations in doses, time observation, and method variations (agar well, disc-diffusion, and turbidimetry) using comparison variables positive control (ampicillin) and negative control (distilled water). The test results showed antibacterial ability with the inhibitory zone category “very strong” and “strong” with 100 % inhibition against E. coli bacteria 5.954 x 108 CFU/mL and 4.723 x 108 CFU/mL S. aureus. This ability increases with the dose of ferrate addition and decreases with the observation time of inactivation. Bacterial inactivation occurs through oxidation and coagulation adsorption by reactive oxygen species (ROS). E. coli is more sensitive than S. aureus due to its thinner membrane structure, allowing more manageable penetration. This research is expected to overcome the problem of iron waste while turning it into something useful as an antibacterial treatment of pollutants in the aquatic environment.

Effects of soot and plastic fibers on the performance of SCC

Self-compacting concrete is regarded as one of the newest types of concrete due to its durability, efficiency, viscosity, stability, flowability, and resistance. Today, one of the most pressing environmental challenges is the disposal of solid waste, and one of the plastic materials discarded as waste after use is plastic packaging belts. These are made on the basis of polypropylene, as well as the factory Iron smelting mines are the main source of iron oxide waste production. Studies using recycled plastic fibers (30 mm × 0.3 mm) and waste iron oxide as cost-effective additives in self-compacting concrete (SCC) are presented. The effects on fresh and hardened properties were evaluated at various additive contents. Fresh and hardened properties of self-compacting concrete (SCC) were evaluated with and without fiber and iron oxide additives. Tests included workability (slump flow, funnel), strength (compressive, tensile), and durability (ultrasonic pulse speed, permeability). Experiments revealed that increasing the amount of recycled plastic fibers and waste iron oxide in self-compacting concrete (SCC) led to higher compressive and tensile strengths at both 7 and 28 days. These strength increases ranged from 2 to 9.68 MPa for compressive strength and 1.61–7.44 MPa for tensile strength, compared to the control specimen without additives.

Predicting compressive strength of concrete with iron waste: a BPNN approach

Predicting compressive strength of concrete with iron waste: a BPNN approach

Studies of the Morphology of Hematite Synthesized from Waste Iron Sulfate.

Microwave-based reactions have gained traction in recent years due to their ability to enhance reaction rates and yield while reducing energy consumption. Also, according to the conception of 'waste to materials', various waste feeds are intensively sought to be tested. The experimental setup of this study involved varying pH levels, oxidation agents, and precipitation agents to optimize the synthesis process of iron red based on waste iron sulfate. The selection of oxidation and precipitation agents was found to significantly influence the pigment synthesis process. Various oxidizing agents, including hydrogen peroxide and atmospheric air, were evaluated for their effectiveness in promoting the oxidation of ferrous ions to ferric ions, essential for pigment formation. Additionally, different precipitation agents such as sodium hydroxide and ammonia solution were assessed for their ability to precipitate iron hydroxides and facilitate pigment particle formation. The characterization of synthesized pigments revealed promising results in terms of quality and color properties. Helium Ion Microscopy (HIM) analysis confirmed the formation of well-defined pigment particles with controlled morphology. X-ray diffraction (XRD) studies provided insights into the crystalline structure of the pigments, indicating the presence of characteristic iron oxide phases. By improving this technology, waste iron sulfate can be efficiently transformed into valuable iron pigments, offering a sustainable solution for waste management while meeting the growing demand for high-quality pigments.

Removal enhancement of persistent basic fuchsin dye from wastewater using an eco-friendly, cost-effective Fenton process with sodium percarbonate and waste iron catalyst.

In this comprehensive investigation, we evaluate the efficacy of the Fenton process in degrading basic fuchsin (BF), a resistant dye. Our primary focus is on the utilization of readily available, environmentally benign, and cost-effective reagents for the degradation process. Furthermore, we delve into various operational parameters, including the quantity of sodium percarbonate (SPC), pH levels, and the dimensions of waste iron bars, to optimize the treatment efficiency. In the course of our research, we employed an initial SPC concentration of 0.5 mM, a pH level of 3, a waste iron bar measuring 3.5 cm in length and 0.4 cm in diameter, and a processing time of 10 min. Our findings reveal the successful elimination of the BF dye, even when subjected to treatment with diverse salts and surfactants under elevated temperatures and acidic conditions (pH below 3). This underscores the robustness of the Fenton process in purifying wastewater contaminated with dye compounds. The outcomes of our study not only demonstrate the efficiency of the Fenton process but highlight its adaptability to address dye contamination challenges across various industries. Critically, this research pioneers the application of waste iron bars as a source of iron in the Fenton reaction, introducing a novel, sustainable approach that enhances the environmental and economic viability of the process. This innovative use of recycled materials as catalysts represents a significant advancement in sustainable chemical engineering practices.

Approaching the circular economy: Biological, physicochemical, and electrochemical methods to valorize agro-industrial residues, wastewater, and industrial wastes

The circular economy policy enables the use of waste as an input to generate value repeatedly or at least to have the opportunity to be used a second time to extract valuable substances such as metals, dyes, hydrogen, phosphorus, nitrogen, nutrients, and fertilizers. For this reason, the present paper discusses approaches to valorizing wastewater, communal production, and agricultural wastes. In particular, techniques are considered to valorize biomass, lignin-containing residues, wastewater with a high organic content, sewage sludge, oily sludge, mine tailings, fly ashes, and iron production wastes. The procedures evaluated include biological processes, microbial fuel cells, electrokinetics, electro-demulsification, electrodialysis, and the Fenton process; their rational application promotes the reuse of different chemical and biological compounds to eventually supply some economic sectors with raw materials in a sustainable manner, solve the problem of pollution in the environment, and generate power at the same time. Of particular and emerging interest is the valorization of iron wastes, which serves to obtain low-cost catalysts for wastewater treatment processes. Additionally, the correct characterization of the chemical composition of wastes and determination of their final use allows better results and less time to valorize any wastes considered.

Possibilities of Managing Waste Iron Sorbent FFH after CO2 Capture as an Element of a Circular Economy.

With a growing need to reduce greenhouse gas emissions, innovative carbon dioxide sorbents are being sought. One of the sorbents being tested is nanoparticle ferric hydrosol (FFH). In parallel with sorbent testing, it is also necessary to test the used sorbent after carbon dioxide capture (FFHCO2) and to develop an optimal method for its processing and management. The research described in this article evaluated the potential use of FFHCO2 in dewatering, coagulation and bioleaching processes. The research results indicate that the basic strategy for dealing with waste FFHCO2 sorbent should be to minimize the amount of waste by volume reduction-dewatering. Recycling of FFHCO2 as an iron waste coagulant or its processing products by bioleaching had no technological justification. It is only proposed to recover the material-iron compounds-if it is environmentally and economically justified.

Thermophysical Properties of Concrete Blended with Iron Powder and/or Iron Fibers

Abstract The use of iron waste in concrete is now of considerable importance, mainly because of the benefits for the environment and for improving the strength of concrete. The increased and unused of this industrial byproducts represents a challenge for the environment and human health. This article experimentally explores the influence of utilizing iron powder waste and iron fibers in concrete in order to enhance the thermophysical properties of concrete and reduce the environmental impact resulting from iron waste. The aim of this work is to study the thermophysical properties (thermal conductivity, volumetric heat capacity, thermal diffusivity and thermal effusivity) of concrete with waste iron powder and iron fibers for application in building construction. The iron powder waste was added to the concrete with different percentages of 0%, 5%, 15%, 20% and 25% respectively as a partial replacement of sand. The iron fibers were added with mix proportions including 1.0%, 1.5%, 2.0% and 2.5% by volume of concrete, and in two different arrangements, uniform and random. The thermal conductivity and the volumetric heat capacity of these samples were measured experimentally in the dry state at ambient temperature (20 °C), and at 28 days of age. The effect of the integration of iron powder and fiber on thermal properties was analysed.

Simultaneous removal of nitrogen, phosphorus, and organic matter from oligotrophic water in a system containing biochar and construction waste iron: Performances and biotic community analysis

The issue of combined pollution in oligotrophic water has garnered increasing attention in recent years. To enhance the pollutant removal efficiency in oligotrophic water, the system containing Zoogloea sp. FY6 was constructed using polyester fiber wrapped sugarcane biochar and construction waste iron (PWSI), and the denitrification test of simulated water and actual oligotrophic water was carried out for 35 days. The experimental findings from the systems indicated that the removal efficiencies of nitrate (NO3–−N), total nitrogen (TN), chemical oxygen demand (COD), and total phosphorus (TP) in simulated water were 88.61%, 85.23%, 94.28%, and 98.90%, respectively. The removal efficiencies of actual oligotrophic water were 83.06%, 81.39%, 81.66%, and 97.82%, respectively. Furthermore, the high−throughput sequencing data demonstrated that strain FY6 was successfully loaded onto the biological carrier. According to functional gene predictions derived from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, the introduction of PWSI enhanced intracellular iron cycling and nitrogen metabolism.

Optimizing compressive strength in sustainable concrete: a machine learning approach with iron waste integration

Optimizing compressive strength in sustainable concrete: a machine learning approach with iron waste integration

Extraction of gamma iron oxide (γ-Fe2O3) nanoparticles from waste can: Structure, morphology and magnetic properties

In this work, the transformation of waste iron cans to gamma iron oxide (γ-Fe2O3) nanoparticles following acid leaching precipitation method along with their structural, surface chemistry, and magnetic properties was studied. Highly magnetic iron-based nanomaterials, maghemite with high saturation magnetization have been synthesized through an acid leaching technique by carefully tuning of pH and calcination temperature. The phase composition and crystal structure, surface morphology, surface chemistry, and surface composition of the synthesized γ-Fe2O3 nanoparticles were explored by X-ray diffraction (XRD), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Energy-dispersive X-ray spectroscopy (EDS). The XRD results confirm the cubic spinel structure having crystallite size 26.90–52.15 nm. The XPS study reveals the presence of Fe, O element and the binding energy of Fe (710.31 and 724.48 eV) confirms the formation of γ-Fe2O3 as well. By dynamic light scattering (DLS) method and zeta potential analyzer, the particle size distribution and stability of the systems were investigated. The magnetic behavior of the synthesized γ-Fe2O3 nanoparticles were studied using a vibrating sample magnetometer (VSM) which confirmed the ferrimagnetic particles with saturation magnetization of 54.94 emu/g. The resultant maghemite nanoparticles will be used in photocatalysts and humidity sensing. The net impact of the work stated here is based on the principle of converting waste into useful nanomaterials. Finally, it was concluded that our results can give insights into the design of the synthesis procedure from the precursor to the high-quality gamma iron oxide nanoparticles with high saturation magnetization for different potential applications which are inexpensive and very simple.

Effect of partial replacement of volcanic ashes by waste iron powder on the properties of phosphate inorganic polymers

This study focuses on the effect of partial replacement of volcanic ash (VA) by waste iron powder in the synthesis of phosphate inorganic polymers (PIPs) based of volcanic ashes. For this purpose, 0, 5, 10, 15, and 20% of the waste iron powder were substituted for those of two volcanic ash named MaJ and Mbo. Subsequently, all the powders were mixed with a solution of H3PO4 (6 M) with a liquid/solid mass ratio of 0.45. The raw materials were characterized by XRF, BET, XRD and FTIR. In addition to these characterization techniques, the obtained synthesis products were also characterized by Optical Microscopy. The properties of the 28-day old specimens were evaluated by determining the compressive strength, density, percentage water absorption and porosity. The results obtained show that the increase in iron powder waste leads to a decrease in compressive strength and density and, in parallel, an increase in porosity and water absorption. In combination with the BET analyses, the observation of the optical micrographs shows that for a partial replacement of 10% of the ash powder (Mbo) by the iron powder waste leads to an increase in the specific surface of the synthesis products and an increased presence of voids within the Mbo-based specimens. On the other hand, for the same content, we observe an occupation of the pores within the MaJ-based specimens. All these results show that iron powders wastes lead to an expansion of the pore volumes in our materials and make them more fragile. Therefore, iron powders can be used as a pore-forming agent in the synthesis of porous Mbo-based PIPs and as fillers for MaJ based PIPs.

An investigation of self-sensing and mechanical properties of smart engineered cementitious composites reinforced with functional materials

Abstract In this study, hybrid functional fillers were used to create an electrical network that is used to develop self-damage sensing ability within conventional cementitious mixtures. This electrical network was used to examine the self-sensing properties of cementitious composites under different loading scenarios such as compression, splitting tensile, and cyclic loading for three ages, those are 7, 14, and 28. With the help of a single type of functional filler or fiber, the self-sensing capabilities of the majority of previous works are demonstrated. This study incorporates two types of functional fillers for sustainability and low cost: micro-scale carbon fibers (CF) and waste iron (Ir) powder in the form of microparticles. The purpose of the current work is to fill up the subject’s gap using two different types of functional fillers as a hybrid form. Three hybrid proportions of a micro-scale CF (vol% of mixture) and waste iron powder (Ir) (wt% of cementitious materials) are utilized. These are (0.33, 15), (0.67, 10), and (1.00, 5), respectively. Unlike carbon-based materials, polyvinyl alcohol is used as a mechanical reinforcing fiber 2% by volume of the cementitious mixture. Additionally, a control combination without any fillers has been created. The electrical resistivity of the fabricated samples was monitored during various loading applications for every second to confirm their self-sensing capabilities. Regarding the fractional change in electrical resistivity, the self-sensing behavior was superior for mixes containing high dosages either of waste iron powder or CF in the same hybrid matrix. Quite the contrary to that, the piezoresistivity was modest in the middle hybrid ratio.

A comprehensive study of As(V) removal by starch-coated magnetite nano-adsorbent based on waste iron sludge

Combining natural polymer starch with magnetite nanoparticles (MNPs) can reduce the aggregation of MNPs and enhance their adsorption capacity and stability. Iron sludge from a de‑ironing water plant and starch were employed as basic ingredients in this study. Bare magnetite nanoparticles (MNPs) and starch-coated magnetite nanocomposites (ST2-MNPs) were synthesized by a “green” co-precipitation method for the removal of low-concentration As(V) solutions. TEM, XPS, FTIR, XRD, VSM, BET, and TGA techniques were used to examine the physicochemical properties of the synthesized ST2-MNPs. TEM verified that the magnetite nanoparticles in the composites were evenly distributed. The ST2-MNPs (5.26 nm) possessed a smaller average particle size than MNPs (6.24 nm). And VSM confirmed their remarkable magnetic properties. The starch-to‑iron-sludge ratio was optimized and the influence of adsorbent dosage, pH, and co-existing anions on As(V) adsorption were studied. The acquired arsenate adsorption data were found to be consistent with the Langmuir isotherm model, with maximum adsorption capacities of 23.04 mg/g for MNPs and 42.88 mg/g for ST2-MNPs. This shows that the active sites on MNPs and ST2-MNPs are energetically homogenous, and that the addition of starch coating significantly increases magnetite's adsorption capacity for As(V). The adsorption kinetics follow a Pseudo-second-order kinetic model, indicating chemisorption between As(V) and ST2-MNPs. In addition, the adsorption mechanism of As(V) by ST2-MNPs including chemical adsorption and electrostatic attraction was determined through in-depth discussion of characterization methods and adsorption experiments. This study offers references for the removal of As(V) and the resourceful application of backwash iron sludge.

Green magnetic carbon/alginate biocomposite beads from iron scrap waste for efficient removal of textile dye and heavy metal

The circular economy can help enhance the value of industrial waste and remediate the environment. This study considers the application of iron scrap from steel production as a free resource to produce magnetic adsorbent beads to remove methylene blue dye and lead (II) ions from wastewater. Composite beads were prepared by incorporating iron scrap and activated carbon into a calcium alginate gel using a simple ‘mix and drop’ synthesis. The optimized magnetic beads were stable and offered a large specific surface area. The maximum adsorption capacity of the adsorbent, calculated from the Langmuir isotherm model, was 476.19 mg g−1 for methylene blue and 163.93 mg g−1 for lead (II) ions. This study places emphasis upon the zero-waste principle and employs a scalable synthetic approach for the conversion of waste iron scrap into an adsorbent material capable of delivering significant environmental benefits.

Recycling of Waste Iron Tailings by Biomineralization for Cemented Paste Backfill Production

Recycling of Waste Iron Tailings by Biomineralization for Cemented Paste Backfill Production

Performance analysis of thermally and non-conductive cement mortar prepared from waste iron scraps and magnetite sand

ABSTRACT The existing thermal conductive pavement exploits heating cables as the heat source commonly. However, the poor thermal conductivity of the upper layer in the pavement structure results in a low energy utilisation efficiency. In order to ensure energy transfer efficiency and reduce energy consumption, this paper investigates the application of waste iron scraps and magnetite sand in cement-based materials. The mechanical properties, electrical conductivity and thermal conductivity of cement mortar were tested by ISO method, two-electrode method and plate steady-state method, and the drying shrinkage condition of the specimens was studied by drying shrinkage test. The results showed that there was a critical value of mechanical property enhancement of mortar by waste iron scraps and magnetite sand, while the electrical and thermal conductivity were positively correlated with their admixtures. The study obtained the optimal ratio of waste iron scraps and magnetite sand in the system that would exhibit excellent thermal and mechanical properties while having low electrical conductivity. It can be concluded that this study provides suggestions for solving the problems of low exploitation rate of solid waste and low heat transfer efficiency of thermal conductive pavement.

Waste Iron Dust Derived Iron Oxide Nanoparticles for Efficient Adsorption of Multiple Azo Dyes

Waste Iron Dust Derived Iron Oxide Nanoparticles for Efficient Adsorption of Multiple Azo Dyes