Sustainable Water Purification: Iron Filings for Dye Adsorption

ABSTRACT This study evaluated the storage behavior of groundnut under two experiments. In the first, grains were stored in PVC drums at 40% CO 2 concentration. In the second, hermetic, traditional polyethylene, and jute bags were used, with oxygen absorbers (iron filings, 40 g, and NaCl, 4 g) for 50 kg grains to reduce O 2 levels to ~10%. Cocoon bag was exclusively tested for groundnut storage. Hermetic bags maintained higher CO 2 levels (7.81%) compared to polyethylene (3.48%) after 180 days. Cocoon bag stabilized CO 2 at 48% and O 2 at 9.6%, minimizing free fatty acid changes (0.43% to 0.68%). Thousand‐grain weight losses were minimal, with final weights of 872.20 g. The study demonstrated hermetic systems' potential to reduce post‐harvest losses and maintain seed viability.

Biogas has been widely recognized as a viable alternative energy source; however, its commercial use remains limited due to challenges with storage and transportation. This study elucidates the processes involved in the production, scrubbing, compression, and storage of biogas derived from cow dung, with the aim of enhancing its portability and combustion efficiency. A total of 385 kg of fresh cow dung was anaerobically digested in a 1 m³ floating-dome digester for a retention period of seven days to generate raw biogas. The raw biogas was subsequently purified through a three-stage scrubbing system: carbon dioxide (CO₂) was removed by chemical absorption using 100 g/L calcium oxide (CaO) slurry, hydrogen sulfide (H₂S) was eliminated using 863 g of iron filings via adsorption, and water vapor was extracted using 498 g of silica gel crystals. The purified biogas was compressed to an absolute pressure of 4 bar using a refrigerant compressor and stored in a 23.7 L compressed natural gas (CNG) cylinder. The compression process was completed within 4.54 minutes, with direct proportional relationships observed between compression time, cylinder pressure, and compressor surface temperature. The performance of the compressed biogas was evaluated through water boiling and food cooking tests and compared with raw biogas and conventional fuels (kerosene, firewood, charcoal, and butane gas). The scrubbed and compressed biogas boiled 1 liter of water in 7 minutes and 49 seconds, representing a 33% reduction in boiling time compared to raw biogas (11 minutes and 37 seconds). Similarly, cooking 1 kg of rice required 30 minutes with purified biogas, compared to 45 minutes with raw biogas, indicating a 33% improvement in cooking efficiency. These findings demonstrate that the sequential scrubbing of CO₂, H₂S, and water vapor using locally available materials significantly enhances the calorific value and combustion performance of biogas, while compression facilitates its storage and transportation. The study establishes a replicable low-cost system for producing portable high-energy biogas suitable for domestic applications.

A This article focuses on the study of physicochemical processes occurring during the filtration of carbonated water through a porous medium simulating an oil reservoir. The aim of the research is to understand the mechanisms of enhanced oil recovery (EOR) and to assess the possibilities of CO2 sequestration in depleted reservoirs. The experiments were conducted in a dynamic mode, which allowed approximating laboratory conditions to real technological processes. The relevance of the work is due to the insufficient understanding of chemical reactions during the injection of carbonated water, which limits the effectiveness of existing technologies. The scientific novelty lies in the experimental confirmation of hydrocarbon synthesis, including methane, ethane, propane, and heavy hydrocarbons (С10–С20), under conditions simulating natural processes, which supports the biospheric concept of oil and gas genesis. The dependence of hydrocarbon yield on pressure, filtration rate, and contact time with the catalyst was established. The main results include the formation of hydrogen (68–85% vol.), methane (5–12%), ethane (0.2–0.8%), propane (0.1–0.5%), and carbon monoxide (0.3–1.2%) during filtration through iron filings. Deposition of heavy hydrocarbons on the catalyst was observed, and the concentration of hydrogen increased with increasing pressure from 3 to 12 atm. The Fischer-Tropsch mechanism was confirmed as the main pathway for hydrocarbon synthesis. The obtained data are important for the development of EOR and CO2 sequestration technologies, as well as for deepening the knowledge of hydrocarbon formation processes in nature.

This study systematically evaluated the removal performance of iron–carbon (Fe/C) micro-electrolysis materials with different proportions and preparation methods for nitrogen (N), phosphorus (P) and chemical oxygen demand (COD) in domestic sewage. This study investigated the effects of different Fe/C ratios, hydraulic retention time (HRT), raw materials and sintering bonding conditions on the efficiency of domestic sewage treatment through both static and dynamic experiments. In the static experiments, iron filings (IFs), steel slag (SS), and coconut shell carbon (CSC) were physically mixed, whereas the dynamic tests simulated the continuous treatment of domestic sewage. The results indicated that the Fe/C materials effectively removed P, particularly materials with high Fe/C ratios, which achieved removal rates of 96–98%. The COD removal efficiency of low Fe/C ratio material was better, reaching a removal rate of more than 70% under the optimal conditions. For Fe/C physical mixed materials, SS replacing IFs had excellent performance in ammonia nitrogen (NH4+-N) removal (>93%), but other indicators were poor, which limited its application. Results from the continuous flow experiment indicated that the physically mixed filler with an Fe/C mass ratio of 2:1 showed excellent and stable TP and COD removal rates (98.6% and 92.8%) for the actual domestic sewage. In addition, the Fe/C micro-electrolysis filler sintered at 400 °C using kaolin as a binder exhibited good potential for pollutant removal, providing a feasible solution for reducing energy consumption. This study provides important data support for the development of low-cost and efficient decentralized rural sewage treatment technology.

Introduction: Population growth is accompanied by a significant increase in waste production of all kinds, including that from latrines, which raises serious health and environmental issues. Furthermore, in today’s energy-intensive lifestyle, the exploration and utilisation of new renewable, sustainable, and environmentally friendly energy sources is imperative. Aims: This study aims to explore the potential for energy recovery (biogas) from septic tank sludge in Benin. Place and Duration of Study: Liquid sludge samples were collected from 29 May to 2 June 2023 at the Sludge Treatment Station (STS) in Adjagbo, within the commune of Abomey-Calavi. Methodology: Sludge is subjected to anaerobic co-digestion with simple fruit waste and in the presence of iron filings. The process lasted between 17 and 24 days, depending on the composition of the digester. Results: The raw biogas obtained comprises methane and carbon dioxide in proportions ranging from 55.2% to 65.3% and 34.7% to 44.8% for simple co-digestion, respectively, and between 60.82% and 71.35% and 28.65% to 39.18% in the presence of iron filings. The results demonstrated the effectiveness of iron filings in biogas production and a reduction in process duration during co-digestion compared to simple digestion of fruit waste. Conclusion: This study provides avenues for exploring the valorisation of sludge into renewable energy and considers the use of biodigesters in households as an alternative to conventional septic tanks. The results of this study provide valuable insights to guide effective sludge waste management practices in Benin.

Peroxidase mimics through DEHP-rich plastic wastes upcycling for colorimetric sensing neonicotinoid insecticides.

The incidence of fire accidents resulting from refrigerant leaking following the rupture of air conditioning condenser tubes has escalated in recent years. Corrosion from carboxylic acid is a primary cause in the rupture of copper tubes. The influence of lubricating oil and iron filings generated by the wear of air conditioning compressors on the corrosion of condenser copper tubes is rarely mentioned in the existing research. In order to simulate the environmental conditions inside the air conditioning unit, this study utilizes acetic acid vapor to corrode copper tubes and explores the effects of lubricating oil and iron powder on copper tube corrosion. The results demonstrate that copper corrosion follows a dendritic corrosion pattern, achieving a maximum depth of 51 μm after 28 days in 1% acetic acid vapor. A small amount of copper hydroxy acetate appears in the early stage. Copper hydroxy acetic and basic carbonate copper are converted into acetic acid copper hydrate as the acetic acid vapor increases over time. The ultimate products appear as turquoise-blue crystals. POE lubricant diminishes the corrosion rate by establishing an oil layer barrier that mitigates the volatilization of acetic acid. Iron powder preferentially reacts with acetic acid to initially protect the copper tube. The Fe3+ produced oxidizes the copper in acetic acid, hence the concentration of copper acetate rises, which facilitates the crystallization of copper acetate.

This study reports on the magnetic properties of commercial cornflakes, which are primarily influenced by the iron content. An initial analysis of X-ray fluorescence on a brand of cornflakes evidenced the presence of a high concentration of Cl and up to 10.9 mg/100 g of Fe. After the extraction of iron from the cornflakes of two different brands, as iron filings, X-ray diffraction measurements indicate the presence of crystals of elemental iron, and no traces of other crystals of iron-derived compounds were found. The Fourier Transform Infrared analysis on the iron filings does not show any binding between iron and oxygen, which further discards the presence of iron oxides. The magnetic hysteresis loops of whole powdered cornflakes exhibit weak Langevin-like magnetizations, which principally correspond to the iron used as a fortification element. The diamagnetic behavior of the higher organic material content significantly attenuates this magnetic response. The hysteresis loops of the iron filings reached magnetic saturations 1% and 5% lower than those of a pure iron sample. Additionally, the indirect measurement of magnetic susceptibility of the iron filings by magneto-thermograms revealed only one Curie transition very close to 771 °C, which corresponds to pure elemental iron.

Transport and removal of viruses in soil: Evaluating low-cost filtering materials for groundwater protection.

Effective role and mechanism of scrap iron filings in controlling hydrogen sulfide production in septic tanks.

Nowadays, the green economy dictates the urge for finding innovative construction materials to be compatible with the future needs. The growing potential of electric vehicles (EVs) necessitates the transformation towards sustainable and magnetizable concrete pavement. The primary objectives of this work are to determine the optimal materials and mixing proportions to produce high-performance magnetizable mortars for pavement applications. The experimental testing program includes assessing the magnetic properties through the inductance test, the fresh properties using the mini-slump test, the hardened properties through the compressive strength at 3, 7, and 28 days, and the durability through chemical soundness and abrasion resistance. It may be concluded that the magnetic properties of Portland cement mortars can be enhanced through the incorporation of natural magnetite (25% replacement), slag (25% replacement), and scrap iron fillings (70% replacement), and importantly, the addition of enhancers such as magnets, steel mesh, and/or steel bars. These magnetizable mortars can be used for rigid pavement applications since they have a higher abrasion resistance.

Green tea comes from the Camellia sinensis (L.) Kuntze tea plant, a member of the Theaceae family. In various traditional medicine systems such as Ayurveda, Unani, and homeopathy, it has been widely used for its therapeutic properties, including its astringent, diuretic, stimulant, and cardioprotective effects. Tea, one of the most widely consumed beverages globally, contains a variety of bioactive compounds including caffeine, polyphenols, and minerals, which contribute to its health benefits. With rising concerns over adulteration in widely consumed products like tea and coffee, this study aimed to assess the caffeine content and identify adulterants in different branded and unbranded tea samples from the Udupi district of Karnataka, India. Results revealed that branded teas generally had higher caffeine content and lower levels of adulteration compared to unbranded samples. Several unbranded teas were adulterated with harmful substances such as coal tar dye, iron filings, and leather flakes, posing potential health risks. This research underscores important public health concerns, particularly in regions with limited food safety regulations, and highlights the need for stricter quality control and consumer awareness.

Abstract Solar cookers cannot be used without heat storage during cloudy periods or at night. Heat storage can be used for cooking during cloudy periods and at night. Two storage cooking pots are thus experimentally evaluated to compare their heat storage performances. A latent heat storage material (erythritol) is compared with a sensible heat storage material (powdered iron filings) during solar cooking periods using parabolic dish solar cookers and during storage cooking periods using wonderbag insulating solar cookers. The powdered iron filings storage pot shows a faster temperature rise during the no-load test, attaining a maximum pot temperature above 200 °C compared to 190 °C for the erythritol due to the higher thermal conductivity of iron filings. However, the storage temperature for erythritol at the end of the no-load lest is around 180 °C compared to 140 °C for iron filings. For the storage cooking period, the erythritol storage pot can boil water. In contrast, the iron filings storage pot shows ineffective heat transfer, achieving a maximum temperature of only about 70 °C. For the simultaneous heating and storage test, the iron filings pot shows higher temperatures during the solar cooking period and much lower temperatures during the storage cooking period than the erythritol pot.

Tuned Liquid Dampers (TLDs) are dissipative devices that mitigate vibrations through the out-of-phase movement of a fluid, typically water, inside a container relative to a main structure. Water’s low density and viscosity have led to modifications to enhance their effectiveness. Fluid properties, such as density or viscosity, significantly impact their performance by altering mass and damping, respectively. When magnetorheological fluids are employed, magnetic fields can modify the fluid viscosity, affecting the damping. This study experimentally examines the effect of a magnetic field and ambient parameters on the viscosity of different low-cost, custom-prepared magnetic fluids. A tube filled with magnetic liquids into which diverse non-magnetic spheres are dropped was employed, considering on- and off-states of the magnetic field generated by a pair of Helmholtz coils. The impact on the fluid viscosity variation of different measured variables was statistically analyzed. It was found that in all cases, the variations in ambient temperature and relative humidity had no effect on the results. While the magnetic field had a large effect on the viscosity of the magnetic fluid, for the sunflower oil-based fluids, the spheres used or the concentration of iron filings had a greater effect on the viscosity than the presence of the magnetic field.

Concrete is one of the most used construction materials., Mineral admixtures with pozzolanic characteristics, like silica fume, fly ash, ground granulated blast-furnace slag, and metakaolin, are often used to replace Portland cement in construction projects partially. Concrete faces persistent challenges, such as low tensile strength, brittleness, and a propensity to crack. This comprehensive study explores the improvement of partial substitution of Portland cement concrete properties with fly ash and reinforced with steel fibers and iron filings. In total, 45 cubes (150 mm) and prisms (100x100x500 mm) were tested using an M25 mix, varying the steel fiber volume fractions at 0%, 0.5%, and 1.0%. These specimens were subjected to given curing periods, after which compressive and split tensile strength tests were conducted to assess their performance. For comparison, plain concrete specimens of the same mix were also tested. Also, iron filings were incorporated into the concrete mix at three different percentages (0%, 0.5%, and 1%) to assess their influence on compressive and tensile strengths after 28 days. The results demonstrate that the addition of steel fibers significantly enhances the mechanical properties of concrete. After 28 days, compressive strength increased by 8.5% to 24%, tensile strength improved by 15% to 49.43%, and flexural strength increased by 38.5% to 85%. Similarly, the inclusion of iron filings improved compressive strength by 9.78% initially, followed by a decrease of 13.84% at higher content. Tensile strength increased by 24.05% to 34.43%, while flexural strength improved by 21% to 29.7%. However, both steel fibers and iron filings slightly reduced workability, with slump values ranging from 63 mm to 92 mm depending on the material and its proportion. The outcomes provide a comparative analysis of the effect of steel fibers and iron filings on the mechanical characteristics of concrete, and present valuable understandings for optimizing concrete behavior in construction applications.

Upstream Contamination is a counter-intuitive phenomena of fluid dynamics, where particles can go against the liquid stream and climb, higher containers. Previous studies have attributed the movement of particles against the flow of water to the Marangoni effect, where surface tension gradients drive fluid movement. However, the effect was not enough to account for the motion of particles. Meanwhile, this study challenges that explanation by documenting the ascent of fine particles of Iron Fillings, through a water jet where the lower container exhibited higher surface tension due to an aqueous calcium chloride (CaCl2) solution. Contrary to the Marangoni effect, which predicts that particles should move from areas of lower to higher surface tension, our observations showed that the particles can move upwards even from a higher surface tension to a lower surface tension region. Afterward, other factors influencing this phenomenon were studied, including the height of the upper container from the lower one, the angle between the channel and the horizontal axis, temperature, and surface tension gradient. Each of them, suggests that factors other than surface tension gradients, such as fluid dynamics and turbulence, play a significant role in particle behavior in these conditions. This study can help us understand how some 'safe-ecosystems', cell mechanisms and medicine production can be contaminated in an unthinkable way so that these contaminators can be prevented and a safer ecosystem and medicare development can be ensured and steps to safeguard protoplasm from harmful contaminants can be taken.

The Como Treasure, discovered in 2018 during archaeological excavations in the Roman town of Novum Comum, consists of 1,000 solidi and a few other gold artifacts – three rings, a small piece of an ingot and incomplete and unfinished gold jewelry. It is the most important hoard of Roman gold coins discovered in Central/Western Europe in recent decades. The examination of the solidi allowed for the study of the traces of workmanship and the reconstruction of the operative chain used in Late Antiquity mints. The gold was melted under oxidizing conditions, purified by cupellation and cementation and then assayed. In order to obtain the blanks, foils were made, cut in round plates with iron shears. Then the edges and the weight were adjusted al pezzo with iron files. As some of the impurities visible to the naked eye show on some coins, iron filings from files accidentally got into the filings or gold waste used for melting. Coins were obtained by minting using dies engraved according to a well determined sequence: after a subdivision of the die’s surface with compasses, the figures and finally the inscriptions were engraved. The production process was concluded by checking the weight of the coins. In times of intensive production mints could shorten their production times by recoining old coins. In this case, the purity of the gold was checked by taking a sample from the center of the coins before their recoinage. These different stages required specialized staff and ateliers with different features placed in a building that guaranteed high levels of security and that was well connected to the road network to allow supplies. These characteristics seem to be found in a building unearthed in old excavations in Milan and already interpreted as a bath. On the basis of the information currently available, however, the possibility of it being the mint of the comitatus cannot be ruled out.

End-of-pipe filter to reduce phosphorus concentrations from the effluent of green infrastructure underdrains.

Utilizing of iron filings in geopolymer mortar as a target for climate change mitigation