Biotechnological valorization of Arthrospira plantensis for heavy metal and rare earth element recovery from multimetallic effluents [Articol]

Abstract

This study aimed to evaluate the bioaccumulation capacity of the cyanobacterium Arthrospira platensis for heavy metals and rare earth elements (REEs) from mono- and polymetallic effluents. Experimental systems were enriched with metals such as Ni, Cu, Zn, Cr, Fe, Sr, Mo, and REEs (Dy, La, Tb, Nd, Sm, Yb) at various concentrations. Metal accumulation in biomass was quantified using neutron activation analysis analysis. Biomass productivity was assessed spectrophotometrically based on a calibration curve, while oxidative stress was evaluated via malondialdehyde (MDA) content using the TBARS assay. Results demonstrated high accumulation capacities, with notable values for Cu (2870 mg/kg), Zn (up to 22500 mg/kg), Ni (1310 mg/kg), and La (>90% recovery). Biomass growth and MDA levels varied depending on the metal combination and concentration, indicating stress responses. A. platensis showed consistent resilience and was effective as a biosorbent, especially under moderate oxidative stress. The findings highlight its applicability in the bioremediation of wastewater containing diverse metal contaminants and its potential use as a matrix for biofortified supplements.