Abstract: A treatment system for removing metal ions from water. Contaminated water is first passed through a nanofiltration membrane system, and then through one or more columns having ion-extracting materials therein. The nanofiltration membrane system involves at least one and preferably multiple nanofiltration membrane units which are capable of removing metal ions from water. To remove any residual metal ions from the permeate generated by the nanofiltration membrane system, the permeate is passed through at least one and preferably multiple columns filled with porous polymer beads having metal ion extracting agents therein (e.g. biomass materials). As a result, highly purified water is produced. When saturated with ions, each bead-containing column is successively cleaned with acid solutions.

Abstract: A treatment system for removing metal ions from water and a method for cleaning the system. Contaminated water is passed through a plurality of columns having ion-extracting agents therein. When saturated with ions, each column is successively cleaned with primary and secondary acid solutions from separate vessels. When the primary acid is saturated with ions, it is membrane-filtered to remove ions therefrom. The secondary acid is then directed into the primary acid vessel, with the purified primary acid being routed back into the system (preferably into the second vessel) for reuse. The column is then rinsed with water, washed with an alkali solution (periodically concentrated using a water-permeable membrane), and rinsed again with water. The system preferably uses three columns, all of which are successively cleaned in the manner described above.