Sorption as a pre-concentration step for metal ions recovery in multi-elemental systems

abstract

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/).

keywords

COMPETITIVE SORPTION; AQUEOUS-SOLUTION; SARGASSUM SP.; HEAVY-METALS; BIOSORPTION; REMOVAL; BIOMASS; CADMIUM; BIOCHAR; SINGLE

subject category

Engineering

authors

Carreira, ARF; Schaeffer, N; Passos, H; Coutinho, JAP

Groups

G4 - Renewable Materials and Circular Economy

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

acknowledgements

This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC). Ana R. F. Carreira acknowledges FCT for the Ph.D. grant SFRH/BD/143612/2019. Nicolas Schaeffer acknowledges the national funds (OE), through FCT-Fundacao para a Ciencia e a Tecnologia, I. P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29th, changed by Law57/2017, of July 19th. Helena Passos acknowledges FCT - Fundacao para a Ciencia e a Tecnologia, I.P. for the researcher contract CEECIND/00831/2017 under the Scientific Employment Stimulus - Individual Call 2017. The authors would like to thank ALGAplus, Lda. for providing algal samples.