Biosorption of Pb²⁺ Ions Using Immobilized Green Algae Biomass Spirogyra setiformis with Sodium Silicate

Nessa Zarlita (Universitas Negeri Padang)
Mawardi Mawardi (Universitas Negeri Padang)

Formosa Journal of Applied Sciences (FJAS)
Vol. 4 No. 10 (2025): October 2025

This study aims to evaluate the adsorption performance of immobilized green algae Spirogyra setiformis biomass using sodium silicate as a biosorbent for the removal of Pb²⁺ ions from aqueous solutions. The investigated variables include pH, initial metal ion concentration, flow rate, and the influence of Cd²⁺ ion coexistence. The experiments were conducted using a column method, in which 1 g of biosorbent was contacted with Pb²⁺ solutions under various conditions. The analytical results revealed that optimum biosorption occurred at pH 5, achieving an adsorption capacity of 3.67 mg/g. The optimum initial concentration was found to be 300 ppm with an adsorption capacity of 6.87 mg/g, while the optimum flow rate of 20 drops/min resulted in a capacity of 6.92 mg/g.