Determination of Optimum Condition of Lead (Pb) Biosorption Using Dried Biomass Microalgae Aphanothece sp.

Abstract

Contamination of lead (Pb) in water due to domestic and industrial activities can endanger the environment and human health. One of the heavy metal waste treatments is adsorption using microorganisms (biosorption). In this study, dried microalgae Aphanothece sp. used as biosorbent for binding Pb in aqueous solution. Biosorbent was prepared from the 14 days cultivation of microalgae in a photobioreactor system which was then dried and mashed to the size of 45 mesh. Pb metal biosorption experiments were carried out in a batch system at various initial concentration variations (3.9–18.6 mg/L) and contact times (30–180 minutes) to find the optimum conditions of the biosorption process. The concentration of Pb in solution was analysed using the Atomic Absorption Spectroscopy (AAS). The results of the experiment showed that the highest removal efficiency of Pb metal in the initial concentration variation of 18.6 mg/L and contact time of 30 minutes was 99.9 % with an absorption capacity of 185.64 mg/g. Pb metal adsorption data at equilibrium conditions follows the Langmuir isotherm model equation with R2>0.9. Biosorption kinetics using dried biomass of Aphanothece sp. following the pseudo second-order kinetics model. The results of this study provide an overview of the potential microalgae as Pb metal biosorbent in wastewater treatment on a larger scale.