Manganese and Aluminium Recovery from Ferromanganese Slag and Al White Dross by a High Temperature Smelting-Reduction Process

The recovery of Mn and Al from two industrial waste of ferromanganese and aluminum production processes was investigated via implementing a high temperature smelting—aluminothermic reduction process. The experiments were carried out with or without CaO flux addition, and two dross qualities. It was observed that the prepared mixtures of the materials yield homogeneous metal and slag products in terms of chemical composition and the distribution of phases. However, the separation of produced metal phase from the slag at elevated temperatures occurs when a higher amount of CaO is added. Viscosity calculations and equilibrium study indicated that the better metal and slag separation is obtained when the produced slag has lower viscosity and lower liquidus. It was found that the process yields Al-Mn-Si alloys, and it is accompanied with complete recovery of Mn, Si and Fe and the unreacted Al in the process. Moreover, the quality of metal product was less dependent on the slightly different dross quality, and the concentration of minor Ca in metal is slightly increased with significant increase of CaO in the slag phase.

Optimization of multiple parameters for adsorption of arsenic (III) from aqueous solution using Psidium guajava leaf powder

The conventional method of water treatment using activated carbon from several sources has been focused extensively since the last two decades. However, rare attention has been noticed on natural adsorbents such as plant leaves. Therefore, the Psidium guajava (Guava) leaf has been investigated to understand it's adsorption efficacy for Arsenic (III) [As(III)] in this study. The effect of process variables, e.g., pH, concentration of metal ion, adsorbent's particle size, and dosages, are evaluated. Experiments are carried out in batch mode, and the individual and combined parameter's impact on adsorption have been discussed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) is used to characterize the adsorbent's surface. Freundlich and Langmuir's isotherms are used for adsorption equilibrium study. The adsorption parameters are optimized by establishing a regression correlation using central composite design (CCD) of response surface methodology (RSM). The analysis of variance (ANOVA) suggests a high regression coefficient (R2 = 0.9249) for the removal of As(III). Particle size of 0.39 mm; adsorbent's height of 10 cm; metal ion concentration of 30 ppm, and pH 6 are optimized to remove 90.88% As(III) from aqueous solution. HCl is evaluated as a potential solvent for desorption of arsenic from desorption study.

Preparation of Palm Oil Industry’s Biomass-Based Graphene Composite for the Adsorptive Removal of Methylene Blue

The ability of POME-based graphene shell composite (P-GSC), an adsorbent generated from oil palm wastes abundantly available in Malaysia such as POME and PKS, was examined in removing methylene blue (MB) dye by adsorption. Adsorption experiments, involving a batch column study and a batch equilibrium study, were conducted to investigate the efficiency of synthesized P-GSC from PKS as a base material in the removal of MB dye. The batch column study demonstrated that small-sized synthesized P-GSC from PKS as a base material could remove up to 98.5% for concentration. Therefore, the following batch equilibrium study was carried out on small-sized P-GSC only. Adsorption isotherms and kinetic isotherms were studied, from which the experimental data showed that the adsorption exhibited a good fit with the Freundlich model ( R 2 = 0.8923 ) and followed the pseudo-second order model ( R 2 > 0.98 ). FESEM, XPS, and XRD morphological and elemental analysis indicated the successful graphinization of POME on the P-GSC surface. The concept of deploying POME as the carbonaceous source to produce P-GSC, and then, deploying the resultant P-GSC as the adsorbent for MB dye removal has presented promising practical potential. Such cost-effective and environmentally friendly reuse of waste materials is envisioned to promote a ‘zero-waste industry.’

Vapour-Liquid Equilibrium Study for the Carbon Dioxide and Hydrogen Sulphide in Deionized Water and NaCl Aqueous Solution at Temperature from 373.15 to 423.15 K

New vapour liquid equilibrium (VLE) data for carbon dioxide (CO2) and hydrogen sulphide (H2S) mixture in deionized water and NaCl aqueous solution are generated at temperature range from 373.15 to 423.15 K and pressure up to 25.0 MPa. A static-analytic type method, taking advantage of two magnetic capillary samplers for phase sampling is used for this VLE measurements. The VLE data generated in this work are compared against literature data, Duan model and the simplified cubic plus association (CPA-SRK72) Equation of State (EoS) model predictions. From the results, it is demonstrated that the CPA-SRK72 EoS model is able to predict the phase behaviour of CO2 and H2S in water and NaCl aqueous solutions with low absolute average deviation (AAD) against the measured experimental data.