Reuse potential of residues of artichoke (Cynara scolymus L.) from industrial canning processing as sorbent of heavy metals in multimetallic effluents

• Published in: Industrial crops and products 2019-12, Vol.141, p.111751, Article 111751
• Main Authors: Saavedra, María I., Doval Miñarro, Marta, Angosto, José M., Fernández-López, José A.
• Format: Article
• Language: English
• Subjects: Agrowaste biomass; Artichoke; Competitive adsorption; Cynara scolymus; Heavy metals
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2019.111751

[Display omitted] •Artichoke agrowaste biomass is effective for Pb(II), Cd(II) and Cu(II) sorption.•Taguchi DOE approach was used to identify the optimum level of the factors considered at which maximum sorption capacity was achieved.•Pb(II) was predominantly adsorbed at equilibrium, followed by Cd(II) and Cu(II).•Uptake kinetic was best fitted to the pseudo-second order model.•The share of each metal ion(Si) is a good parameter to study the competitive adsorption. The suitability of reusing artichoke agrowaste biomass from industrial canning processing as a low-cost and ecofriendly sorbent for the bioremoval of Pb(II), Cd(II) and Cu(II) in multi-metallic aqueous solutions is reported. Understanding the dynamic of heavy metals in the sorption process is critical to assess the removal of these contaminants in aquatic systems. The Taguchi approach was used to design a series of experiments to find the optimum conditions for maximum total sorption capacity, analysing the signal-to-noise (S/N) ratio to assess the experimental responses. Ranks of five controllable factors (the initial concentrations of Pb(II), Cd(II) and Cu(II), sorbent dosage and pH), at three levels each one, in a L27 array were conducted in batch sorption tests. The highest sorption capacity (241 μmol·g−1) was shown with initial concentrations of 315 μmol L−1 Cu(II), 445 μmol L−1 Cd(II) and 241 μmol L−1 Pb(II), pH 5 and 0.5 g L−1 of sorbent dosage. The metal ion predominantly adsorbed was Pb(II). Adsorption kinetics followed a pseudo-second order model. The study of the shares of each metal ion on the total sorption capacity revealed that Cd(II) is actually prone to be adsorbed but the presence of Pb(II) and Cu(II) hinders its adsorption. The valorization of artichoke agrowaste biomass as metal sorbent is considered a way to assist in the promotion of a circular economy.