Investigation of the Structural and Magnetic Properties of BaM Hexaferrites Prepared from Scrap Iron Filings

In this work, we demonstrate the feasibility of preparing a commercially important type of magnetic oxide, BaM (BaFe12O19) hexaferrite, using scrap iron filings as an iron source. The hexaferrites were prepared by conventional solid state reaction and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and magnetization measurements. XRD patterns of samples prepared by mixing powders extracted from the iron filings with appropriate amounts of barium carbonate and sintering at 1200 °C revealed the presence of a major BaM hexaferrite with small amounts of nonmagnetic α-Fe2O3 oxide phase. On the other hand, SEM images of the samples showed clear crystallization of perfect hexagonal platelets of BaM hexaferrite, which was further confirmed by the Curie temperature determined from the thermomagnetic measurements. The saturation magnetization of the samples was in the range of 45.1– 52.1 emu/g and the remnant magnetization in the range of 14.8 – 19.0 emu/g. These values and the moderate coercivity of ~ 1 kOe suggest that the prepared samples could potentially be useful for high-density magnetic recording. Keywords: Hexaferrite, Solid waste, Magnetic Properties, Structural properties, Magnetic recording.

New Composite Sorbent for Removal of Sulfate Ions from Simulated and Real Groundwater in the Batch and Continuous Tests

The evaluation of groundwater quality in the Dammam formation, Faddak farm, Karbala Governorate, Iraq proved that the sulfate (SO42−) concentrations have high values; so, this water is not suitable for livestock, poultry and irrigation purposes. For reclamation of this water, manufacturing of new sorbent for permeable reactive barrier was required through precipitation of Mg and Fe hydroxides nanoparticles on the activated carbon (AC) surface with best Mg/Fe molar ratio of 7.5/2.5. Mixture of 50% coated AC and 50% scrap iron was applied to eliminate SO42− from contaminated water with efficiency of 59% and maximum capacity of adsorption equals to 9.5 mg/g for a time period of 1 h, sorbent dosage 40 g/L, and initial pH = 5 at 50 mg/L initial SO42− concentration and 200 rpm shaking speed. Characterization analyses certified that the plantation of Mg and Fe nanoparticles onto AC was achieved. Continuous tests showed that the longevity of composite sorbent is increased with thicker bed and lower influent concentration and flow rate. Computer solution (COMSOL) software was well simulated for continuous measurements. The reclamation of real contaminated groundwater was achieved in column set-up with efficiency of 70% when flow rate was 5 mL/min, bed depth was 50 cm and inlet SO42− concentration was 2301 mg/L.

Ibuprophen Removal from Synthetic Effluents Using Electrocoagulation-Peroxidation (ECP)

Concerning water resources, several ordinances and legislation determine standards and conditions for the discharge of effluents into water bodies. However, several contaminants are not covered by these guidelines because they are found in low concentrations and due to little knowledge of their long-term effects. These contaminants are called emergents, and this category includes drugs, such as anti-inflammatory drugs. The electrocoagulation process associated with advanced oxidation comes up as an alternative to conventional effluent treatment processes, and the objective of this work was to evaluate this process using scrap iron as sacrificial electrodes in the treatment of synthetic effluents containing Ibuprofen. High performance liquid chromatography (HPLC) was used to quantify the drug in synthetic effluents. The CCRD 24 was used in an experimental design, having as independent variables evaluated the concentration of contaminants, applied current, the concentration of the primary oxidizing agent H2O2 and the reaction time. The optimized conditions determined by statistical analysis were drug concentration of 5 mg.L-1, H2O2 concentration of 200 mg.L-1, current of 5 A and 150 min. The removals obtained under these conditions were higher than 92% in the aqueous phase, showing that ECP technique has the potential to treat contaminants such as drugs present in effluents and waters.

Ex-situ biogas upgrading to methane and removal of VOCs in a system of zero valent iron and anaerobic granular sludge

In the current study, a novel process of ex-situ biogas upgrading to biomethane is presented which is based on a system consisted of anaerobic sludge and zero valent iron (ZVI). The ZVI when is added in an aquatic system with anaerobic granular sludge generates H2 under anaerobic abiotic conditions. Then, the H2 and CO2 are converted by the hydrogenotrophic methanogens to CH4. Biogas upgrading to biomethane was achieved in 4 days in a system of anaerobic granular sludge, 50 g L1 ZVI initial pH 5 and 20 g L1 NaHCO3. In this system when zero valent scrap iron (ZVSI) was added instead of ZVI required longer period (21 days) to achieve biogas upgrading. Volatile organic compounds (VOCs) analysis in raw biogas (in system of anaerobic sludge and ZVI) showed mainly the reduction of low mass straight- and branched-chain alkanes (C6-C10); however, no other particular trend regarding the removal of other VOCs was observed. H2S and NH3 were found to be substantially reduced, when the anaerobic sludge was exposed to ZVI compared to no decrease in serum bottles free of ZVI.

Production Decision Optimization for Iron and Steel Scrap Remanufacturing considering Carbon Emission and Delivery Time

Under the requirements of the national carbon reduction target, the recycling and remanufacturing of scrap iron and steel are taken by major iron and steel enterprises as requirements for implementing industrial carbon emission reduction and are incorporated into their production strategies. The scheduling optimization of scrap iron and steel remanufacturing processes plays an important role in the energy saving and emission reduction of iron and steel enterprises. In this paper, a remanufacturing production decision model for scrap iron and steel considering both the product delivery time and carbon emissions was established, and a discrete krill swarm algorithm was designed to solve the multiobjective production decision model. The effectiveness of the model and the algorithm was verified by an example, demonstrating a good decision-making reference for the implementation of energy conservation and emission reduction in iron and steel enterprises.

Remediation of scrap iron contaminated by odorants

In general it can be stated that the newly developed remediation process eliminates naturally applied natural gas odorant - tetrahydrothiophene with an aqueous solution of perborate with the addition of acetic acid at normal temperature by immersion of contaminated metal and plastic material. During a detail laboratory study, it was demonstrated by gas chromatography using a specific sulfur chemiluminescent detector that 1 kg of tetrahydrothiophene could be used to decontaminate 1 kg of tetrahydrothiophene 3.5 kg of sodium perborate in the presence of CH3COOH. The total oxidative decomposition time of the odorant occurred in about 20 hours. At elevated temperatures - 40° C - the process proceeds at a slightly higher rate. A higher ratio of perborate to tetrahydrothiophene also has a positive effect on the faster course and degree of decomposition.

Remediation of scrap iron contaminated by odorants

In general it can be stated that the newly developed remediation process eliminates naturally applied natural gas odorant - tetrahydrothiophene with an aqueous solution of perborate with the addition of acetic acid at normal temperature by immersion of contaminated metal and plastic material. During a detail laboratory study, it was demonstrated by gas chromatography using a specific sulfur chemiluminescent detector that 1 kg of tetrahydrothiophene could be used to decontaminate 1 kg of tetrahydrothiophene 3.5 kg of sodium perborate in the presence of CH3COOH. The total oxidative decomposition time of the odorant occurred in about 20 hours. At elevated temperatures - 40° C - the process proceeds at a slightly higher rate. A higher ratio of perborate to tetrahydrothiophene also has a positive effect on the faster course and degree of decomposition.