Characterization of adsorption ability of Spirulina platensis for copper ions removal from aqueous solutions

Among different techniques used to eliminate heavy metals pollution, biosorption using marine algae was found to be an effective method for cleaning aqueous solutions from heavy metals. Due to their low cost ratio and their effectiveness against a wide range of pollutants, marine algae are considered as potential alternative to common techniques used for environmental decontamination and for many industrial applications. Herein, the aim of this study was to highlight the importance of Spirulina platensis as naturally inspired biosorbent, where data obtained with scanning electron microscope detected considerable changes on the algal surface prior and following copper adsorption. Fourier-transform infrared spectroscopy determined a variety of functional groups available for copper binding. Freundlich isotherm model showed a spontaneous, endothermic as well as entropy favorable sorption behavior of copper ions represented by a linear plot. Maximal biosorption (90.6%) was obtained from a 100 mg copper/L and 0.050 g dry biomass solution, pH 7, at 37 degrees C and following 90 min contact time. As such copper was considerably adsorbed on Spirulina platensis surface and hence could be used as an alternative, economic method for copper elimination from aqueous solutions.

Automated summary

Biosorption using marine algae, particularly Spirulina platensis, has been identified as an effective method for removing heavy metals pollution from aqueous solutions. This study highlights the changes that occur on the algal surface during copper adsorption, as well as the functional groups available for copper binding. The Freundlich isotherm model showed a linear plot, indicating spontaneous, endothermic, and entropy favorable sorption behavior. The maximum biosorption rate was found to be 90.6% under specific conditions.