This text introduces a special class of polymeric ligand exchanger (PLE) with high affinities for anionic ligands. Volume 14 discusses the potential and advantages of micro- and nanofiltration membrane processes for removal of metals; details prevailing equilibrium relationships and supporting experimental data for systems where leaching and ion exchange take place simultaneously; covers cases of uranium cation and gold cyanide anion bisorption and modelling of engineered systems.