Abstract (EN):
Sorption is here proposed as a promising approach for metal pre-concentration and re-covery from wastewater. A study was carried out on the simultaneous sorption of Co2+, Cu2+, Ni2+ and Zn2+ on macroalgae, microalgae and cyanobacteria. The effect of pH, initial metal concentration, metal competition and time of contact on metal sorption were evaluated. Metal competition hampers sorption at the studied metal concentration ranges. The metal counterion (sulfate, chloride or acetate) did not influence metal sorp-tion. The brown algae Sargassum sp. was the most promising sorbent (qmax = 0.66 +/- 0.03 mmol center dot g-1), followed by the microalgae Phaeodactylum tricornutum (qmax = 0.36 +/- 0.02 mmol center dot g-1) and the cyanobacteria Spirulina sp. (qmax = 0.216 +/- 0.007 mmol center dot g-1). All biomass samples showed preferential sorption of Cu2+. The experimental kinetic data were well described by Ho's model, showing chemisorption to be the main sorption me-chanism. Ion-exchange of Ca2+, K+ and H+ also played a significant role in metal sorption. After sorption, metal recovery was achieved resorting to incineration. The metal content of the obtained biochar was 4639-fold higher when compared to the initial aqueous so-lution concentration.(c) 2023 The Author(s). Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY-NC-ND license (http://creati-vecommons.org/licenses/by-nc-nd/4.0/).
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Nº de páginas:
10