Azadirachata indicum (Neem): an effective biosorbent for the removal of lead (II) from aqueous solutions.

Laboratory batch experiments with Azadirachata indicum indicated that this population had an excellent ability to bind lead (II) from its aqueous solution. The experiments carried out examined pH, biomass quantity, time of contact, and temperature dependency. Under optimum conditions, the removal of lead (II) was found to be around 95%. Column experiments were performed to examine the binding of lead (II) to silica-immobilized biomass under flow conditions. During this, a slight decrease in the pH of the effluents was also observed, implying an ion-exchange mechanism for metal binding.