Radiation grafted membranes: innovative materials for the separation of toxic metal ions from industrial effluent.

Toxic metal ions present in industrial effluent lead to a considerable deterioration of ecosystem. A proper effluent treatment approach has to be realized for the separation and the recovery of such metal ions from the waste water. Membranes have shown a promising way to separate metal ions and clean the effluent before discharging them into drains. The most important aspect of the membrane technology is the designing its matrix which suits to selectively bind metal ions from the waste water. Radiation grafting offers unique feature of modifying virtually any polymer film or hollow fibre into a membrane. Desired ion exchange groups or chelating groups may be introduced into the polymer by proper selection of the monomer to be grafted. This method provides excellent control over membrane structure by careful variation in the reaction conditions such as dose, dose rate of the irradiation. As a result, membranes with useful characteristics such as ion exchange capacity and chelating capacity may be designed. The eventual regeneration of membranes for subsequent use in the metal separation makes this process extremely attractive.