An analysis of the processes, kinetics and equilibrium of iron's biosorption on immobilized green microalgae

• Published in: South African journal of chemical engineering Vol. 45; pp. 210 - 220
• Main Authors: Diale, P.P., Hildebrandt, D., Glasser, D., Matambo, T.S., Makgato, S.S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2023; Elsevier
• Subjects: Biosorption; Ca-alginate; Desmodesmus sp; Iron; Remediation; Iron; Biosorption; Remediation; Desmodesmus sp; Ca-alginate
• ISSN: 1026-9185
• DOI: 10.1016/j.sajce.2023.05.007

•Comparative study of biosorption mechanisms, equilibrium, and kinetics of iron on immobilized green microalgae was observed.•The pH affect iron metal biosorption.•At the optimum pH of 6, Fe (II) removal was 82% for Ca-alginate beads and 90% for Immobilized Desmodesmus sp.•Among the microalgae species found in the study, Desmodesmus sp. dominated. Various combustion parameters may be adjusted to lower rates of SOx and NOx emissions produced.•Kinetic studies showed that the biosorption of Fe (II) ions on immobilized microalgae cells followed pseudo-second-order. Metals including Cu, Cd, Ni, Pb, Zn, Hg, Fe and Cr can be found in significant concentrations in acid mine drainage effluent from previous gold mining operations. Even at very low levels, heavy metals and their compounds are very toxic, carcinogenic, mutagenic and teratogenic. Acid mine drainage discharge must therefore be properly treated before disposal. In this study, iron removal from acid mine drainage effluent using immobilized green microalgae is explored. The impact of pH on iron metal concentrations was studied at multiple pH values between 2 and 12 using 0.1 M HCl or NaOH solutions. At pH 6, the optimal value, 82% and 90% of Fe (II) were removed from Ca-alginate beads and immobilized Desmodesmus sp., respectively. It was shown that Fe (II) ions were biosorbed by immobilized microalgae cells in a pseudo-second-order manner. This study demonstrated how immobilized green microalgae showed potential to remove iron from acid mine drainage effluent.