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Adsorption behaviour of As(III) onto synthetic iron-based minerals: a comparative study of akaganeite, goethite and magnetite

Ulatowska Justyna.

Physicochemical Problems of Mineral Processing

2022

Vol. 58, iss. 2

art. no. 144818

The present study compares the adsorption capacity of iron-based minerals in removing As(III) from aqueous solutions. The work contains the results of studies carried out on a laboratory scale. The synthetic material was used in three forms as akaganeite, goethite and magnetite. To characterise the minerals before and after adsorption of As(III), specific surface area, particle size distribution, density, and zeta potential were determined. Additionally, digital and optical micrographs, SEM, and FTIR analyses were performed. In the experimental part, the influence of the main parameters on the adsorption efficiency was investigated (pH, initial concentration, contact time, and amount of adsorbent). Adsorption isotherms were fitted by Freundlich, Langmuir, and DubininRadushkevich models. Pseudo-first-order (PFO), pseudo-second-order (PSO), and intraparticle diffusion (IPD) models were used to fit the kinetics data. Linear regression was used to estimate the parameters of isotherm and kinetic models. FTIR measurements gave helpful information on the synthesised minerals and the As(III) removal process. Results show that As(III) adsorption is related to the iron-based adsorbents, and adsorption efficiency increases in the following order: goethite < magnetite < akaganeite.

Use of synthetic zeolite materials from fly ash to remove copper(II) ions from aqueous solutions

Ulatowska Justyna, Stala Łukasz, Nowakowska Alicja, Polowczyk Izabela

Physicochemical Problems of Mineral Processing

2020

Vol. 56, iss. 6

114--124

Water quality and waste management are two chief problems that the modern world is struggling with. Intensified development of the industry not only leads to the production of large amounts of solid waste that must be stored in landfills but can also result in contaminant emissions into the environment. Enormous quantities of ash produced from coal combustion have been a long-term problem of the industry. Literature studies show that fly ash can be used as a material to produce cheap and efficient zeolite-type adsorbents due to abundance of alumina-silicates in their composition. Fly ashes which were processed into zeolites as a result of alkaline hydrothermal treatment were obtained from two power plants in Poland (in Turów and Zgierz). The obtained zeolite materials and raw fly ash samples were characterised in terms of specific surface area, particle size distribution and density. The structure was also investigated using Fourier transform infrared spectroscopy (FTIR) in the mid- infrared wavenumber range. Two raw fly ashes and two zeolite materials were examined for their ability to remove Cu(II) ions from aqueous solutions. The results showed that the amount of adsorbed copper ions by alkaline-modified fly ash was higher than for unmodified fly ash. The ion removal efficiency is high and exceeds 95%.