Online: ISSN 2784 – 0360 | ISSN – L 2784 – 0360 | Print: ISSN 2784 – 0379 ISSN-L 2784 – 0360

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Harja Maria

Asymmetric Cellulose Acetate Membranes Used in Separation Applications

May 14, 2021 |

Gabriela Ciobanu, Lidia Favier, Maria Harja

ABSTRACT. This work focused on the use of cellulose acetate polymer for the preparation of porous asymmetric membranes using a phase inversion process. These membranes were characterised by scanning electron microscopy, a bubble-point method and sorption measurements. The preparation method used induced membrane anisotropy. The capacity of the membranes in the removal of electrolyte (NaCl) from aqueous solution was investigated. A good retention of 58.6% and a high flux rate of 8.9 × 10–4 m/s using NaCl solution of 200 mg/L concentration were obtained by cellulose acetate membranes prepared with water as non-solvent. The results showed that the membrane performance was affected by the membrane structure, which was determined by the conditions of membrane preparation.

Keywords: cellulose acetate polymer; porous membrane; asymmetric structure; salt rejection.

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Fly Ash Magnetic Adsorbent for Cadmium Ion Removal from an Aqueous Solution

Mar 31, 2021 |

Gabriela Buema, Nicoleta Lupu, Horia Chiriac, Dumitru Daniel Herea, Lidia Favier, Gabriela Ciobanu, Loredana Forminte (Litu), Maria Harja

ABSTRACT. The fly ash generated from a Romanian power plant was used as a starting material in this study. The aim of the study was to obtain a low cost material based on the treatment of fly ash with Fe3O4 for utilization as an adsorbent for cadmium ion removal. The adsorbent that was synthesized was characterized using different techniques. The adsorption process was investigated by the batch technique at room temperature. The quantity of cadmium ion adsorbed was measured spectrophotometrically. The experimental data showed that the material can remove cadmium ions at all three working concentrations. The adsorption capacity increased with an increase in concentration, respectively contact time. The results were analyzed through two kinetic models: pseudo first order and pseudo second order. The kinetics results of cadmium adsorption onto a magnetic material are in good agreement with a pseudo second order model, with a maximum adsorption capacity of 4.03 mg/g, 6.73 mg/g, and 9.65 mg/g. Additionally, the pseudo second order model was linearized into its four types. The results indicated that the material obtained show the ability to remove cadmium ions from an aqueous solution.

Keywords: magnetic adsorbent; adsorption; cadmium ions; kinetic study.

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© by the authors; licensee Journal of Applied Life Sciences and Environment, Iasi, Romania. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)