Lucaci, A.-R.; Bulgariu, L. Biosorption of Technologically Valuable Metal Ions on Algae Wastes: Laboratory Studies and Applicability. Water 2024, 16, 512, doi:10.3390/w16040512.
Lucaci, A.-R.; Bulgariu, L. Biosorption of Technologically Valuable Metal Ions on Algae Wastes: Laboratory Studies and Applicability. Water 2024, 16, 512, doi:10.3390/w16040512.
Lucaci, A.-R.; Bulgariu, L. Biosorption of Technologically Valuable Metal Ions on Algae Wastes: Laboratory Studies and Applicability. Water 2024, 16, 512, doi:10.3390/w16040512.
Lucaci, A.-R.; Bulgariu, L. Biosorption of Technologically Valuable Metal Ions on Algae Wastes: Laboratory Studies and Applicability. Water 2024, 16, 512, doi:10.3390/w16040512.
Abstract
In the context of circular economy that recommends the most efficient use of waste, algae wastes have a huge potential for valorisation. In this study, algae wastes obtained after alkaline extraction of active compounds from two types of marine algae (green algae – Ulva sp. and red algae – Callithamnion sp.), were used as biosorbents to remove metal ions from aqueous effluents. Their efficiency in the biosorption processes was tested for Zn(II), Cu(II) and Co(II) ions, considered technologically valuable metal ions. The batch mono-component experiments performed under optimal conditions (pH = 5.0; 4.0 g biosorbent/L; 22 ± 1C), showed that more than 75 % of the metal ions are removed when their initial concentration is less than 1.25 mmol/L. The very good fit of the experimental data with the pseudo-second order kinetic model and Langmuir isotherm model, and the high values obtained for the maximum biosorption capacity (qmax: Cu(II) (0.52 mmol/g) > Zn(II) (0.41 mmol/g) > Co(II) (0.39 mmol/g) for G-AWB, and qmax: Cu(II) (1.78 mmol/g) > Zn(II) (1.72 mmol/g) > Co(II) (1.66 mmol/g) for R-AWB) highlights the potential use of these biosorbents to remove such technologically valuable metal ions from industrial wastewater. This possibility was tested using industrial wastewater samples obtained from the metal coating industry. Quantitative removal (> 91 %) of Zn(II), Cu(II) and Co(II) ions was obtained when their initial concentration was adjusted to 50 mg/L. Also, the rapid and efficient desorption of these metal ions from loaded-biosorbents, by simple treatment with small volumes of HNO3 (10-1 mol/L), further emphasizes the possibility of their recovery and reuse in the technological circuit. The results included in this study indicate that algae wastes have the potential to be used in industrial effluents decontamination processes and opens new perspectives for the implementation of circular economy principles.
Keywords
algae wastes; biosorption; technologically valuable metal ions; wastewater; decontamination processes
Subject
Environmental and Earth Sciences, Pollution
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
