Sebastian Dudek

Maria Curie-Sklodowska University, Poland

Enhanced arsenic(V) removal by commercially available ion exchanger modified with La(III) ions

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Biography

Sebastian Dudek is a PhD student at the International Doctoral Studies in Chemistry at Maria Curie-Sk?odowska University (Lublin, Poland). Since October 2018 he has worked on a doctoral thesis under the supervision of Prof. Dorota Ko?ody?ska. The topic of his doctoral dissertation concerns the removal of arsenate ions on the ion exchangers modified with lanthanide ions. Since 2019 he has been also employed as a lecturer at the Faculty of Chemistry at MCSU.

Abstract

Arsenic has long been recognized as a toxin and carcinogen. Chronic exposure to arsenic may occur through natural sources such as weathering reactions, volcanic emissions as well as human activities like mining. Of the various risks, exposure to arsenic through contaminated drinking water is probably the greatest threat to human health. Therefore, it requires to look into the problem of arsenic(V) adsorption more intensely to find out an appropriate adsorbent with affinity to arsenate(V) ions. The commercially available adsorbent containing inbuilt iron nanooxide molecules of the goethite structure, Purolite Arsen Xnp (Xnp in short), was chosen to this study. Modification of this sorbent with lanthanum(III) ions lead to obtaining the new material Xnp-La(III). The modification process itself was tested for optimal pH, kinetics, and equilibrium adsorption isotherm study. The sorbent characteristics were made using, among others, SEM, FTIR, and nitrogen adsorption/desorption isotherms. Then, several tests were conducted to compare the adsorption properties of the modified and unmodified material. It was found that Xnp-La(III) was able to completely remove arsenate(V) from water with an initial concentration of up to 50 mg/dm3. Without modification, it was not possible to reach the WHO recommended 10 ?g/dm3 arsenic limit even at an initial concentration of 25 mg/dm3. Moreover, the maximum sorption capacity increased threefold after modification. Such La(III)-based adsorbent can be successfully applied in wastewater purification and used many times after proper regeneration what leads to cost reduction.