Biosorption of lead from aqueous solution by biologically activated date pedicels: batch and column study

Abstract

Biosorption of lead by biologically activated date pedicels using a batch system and a continuous up-flow fixed bed column was studied. Batch experiments were conducted to determine the biosorption capacity, equilibrium time and optimal pH. The maximum biosorption capacity of lead was 11.56 mg g-1 at an optimal pH of 5.2. The Langmuir and Freundlich models were used to explain the equilibrium data. The Langmuir model showed a better fit of data with a correlation coefficient of 0.999. The kinetics of biosorption followed pseudo-second-order model. For continuous biosorption experiments, breakthrough curves were analyzed at different flow rates and porosities of the pedicels’ bed. Breakthrough time, time of saturation, fractional capacity and the optimal area of operation were determined. We concluded that biosorption is favored for its lower rate and porosity.