Lead removal by a natural polysaccharide in membrane reactors.

Industrial wastewaters often contain heavy metal ions that are toxic to many living species. Therefore, economic treatment methods are investigated, involving the sorption of metal ions onto wastes or natural materials. In the present work, the ability of sugar beet pulp, a common waste of the sugar industry, to remove Pb2+ polluted waters is investigated. The kinetic and equilibrium experiments were performed in batch reactor in order to determine the Pb2+ adsorption mechanisms onto the polysaccharide. The dynamic studies of Pb2+ fixation onto the natural polysaccharide involve an adsorption reactor coupled with microfiltration membrane in order to confine the adsorbent particles. A mass balance model based on the Langmuir equilibrium isotherm was used to describe the Pb2+ breakthrough curves. This model successfully simulated the entire breakthrough curves whatever the operating conditions used. It provides a useful tool for process simulation and optimisation.