Effects of pollution and bioleaching process on the mineral composition and texture of contaminated sediments of the Reconquista River, Argentina

TUFO, ANA E.; PORZIONATO, NATALIA F.; CURUTCHET, GUSTAVO

ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH

SPRINGER HEIDELBERG

Lugar: HEIDELBERG; Año: 2018 vol. 25 p. 21368 - 21384

0944-1344

Abstract In this work, we report on the structural and texturalchanges in fluvial sediments from Reconquista River´s basin,Argentina, due to processes of contamination with organicmatter and remediation by bioleaching. The original uncon-taminated matrix showed quartz and phyllosilicates as themain primary mineral constituents and phases of interstratifiedillite-montmorillonite as secondary minerals. It was found thatin contaminated sediments, the presence of organic matter inhigh concentration causes changes in the specific surface area,particle size distribution, size and distribution of micro andmeso, and the morphology of the particles with respect tothe uncontaminated sediment. After the bioleaching process,there were even greater changes in these parameters at thelevel of secondary mineral formation and the appearance ofnanoparticles, which were confirmed by SEM. Especially, wefound the formation of cementing substances such as gypsum,promoting the formation of macroporous aggregates and theweathering of clay components. Our results indicate that thebioleaching not only decreases the content of metals but alsofavors the formation of a material with improved characteris-tics for potential future applications.