Methods and systems for the extraction of metals from an aqueous feed solution containing the metal ions. The aqueous feed solution is contacted with one side of a hydrophilic membrane support while an organic liquid is contacted with an opposite side of the hydrophilic membrane support. Metal ions migrate from the aqueous feed solution through the membrane support and into the organic liquid. The metal ions may be re-extracted from the organic liquid using a strip solution. The steps of extraction and reextraction may be carried out in a system including two hollow fiber membrane modules that each include a plurality of hydrophilic polymer hollow fibers.

A method comprises planarizing a substrate material with a functionalized chemical planarization pad. The functionalized chemical planarization pad includes a plurality of functional groups bonded to a material of the pad. The functional groups are configured to chemically react with the substrate material such that a portion of substrate material bonds to the functional groups. The pad is regenerated by applying a regeneration solution configured to break bonds between the functional groups and substrate material bonded to the functional groups to form removed material. The removed material is complexed in a dissolved complexing agent to form dissolved material in an effluent phase.