Influence of Pigment Extraction on Pb(II) Biosorption of <i>Cladophora</i> and <i>Spirogyra</i> Algae Powder

Abstract

The Cladophora and Spirogyra genera are classified within the green algae division. Species belonging to these genera comprise large filamentous algae, possess significant biomass, and are found in freshwater around the world. These characteristics give Cladophora and Spirogyra high potential to be developed as biological materials. For this study, we harvested fresh Cladophora and Spirogyra and produced algae powder using two of conventional procedures: with pigment extraction and without pigment extraction. The resulting algae powders were subjected to Pb(II) biosorption, and the differences in biosorption rates were subsequently analyzed. Our study found the following: (i) significant differences in cell structure, cell wall thickness, the type and content of cell composition, and the quantity of epiphytes between Cladophora and Spirogyra. This variation influenced the functional groups within the resulting algae powders and their binding sites, which further led to different levels of Pb(II) adsorption. (ii) Glacial acetic acid, a compound commonly employed in pigment extraction procedures, affected the functional groups and the binding sites of the resulting algae powders. For Cladophora algae powder, Pb(II) biosorption was reduced by 16.6 %; whereas for Spirogyra algae powder, Pb(II) biosorption was reduced by 19.8 %. (iii) The pigment extraction procedure exerted the most significant influence on the carbonyl groups and hydroxyl groups in algae powder. (iv) The pigment extraction procedure is not suitable for the preparation of algae powders which will be used for metal ion biosorption.