Biosorption of lead from acidic aqueous solutions using Durvillaea antarctica as adsorbent

Biosorption of Pb2+ from aqueous solutions by dried, brown algae Durvillaea antarctica was studied. A series of batch sorption experiments were carried out, where lead concentration was measured with time in a solution in contact with the algae. The Pb2+ uptake efficiency was determined for different (a) pH levels in the solution (1.5–4), (b) initial lead concentration (200–1200 mg L−1), and (c) contact time between solution and algae (10–10,080 min). osorption kinetics and isotherms were determined from the experimental batch sorption data. The results showed that the second order kinetic model of Ho and Mckay described the biosorption process well; the rate constants ranged from 0.137 to 0.349 mg g−1 min−1 as a function of initial metal concentration. Changes in the pH of the solution did not affect the kinetics significantly for the pH range studied (1.5– 4). Considering conventional empirical isotherm models, the Langmuir model predicts slightly better the biosorption equilibrium at ambient temperature than the Freundlich model at the pH level studied. The Langmuir model showed maximum uptake value of 135.1 mg g−1 and the affinity constant was 2.55 L mg−1. m for future work should be focussed on how to transfer the positive lead batch sorption results to a continuous process that treats lead containing wastewater.