Removing metals from metal containing acidic solutions, such as
contaminated waters and industrial wastewaters, is described. An
amphipathic, heterocyclic, metal-coordinating compound (an extraordinary
ligand) and a sorbent are added to a solution, such that the addition, at
a specific acidic pH of the solution, causes at least some of the
metal-coordinating compound to bind with some of the metal cations and at
least some of the metal-coordinating compound sorbs to the sorbent, along
with any metal cations bound therewith. The compound and the sorbent may
be added to the solution, either together or independently, so that the
compound may bind the metal. The metal binding compound may be a
benzotriazole, a benzothiazole, or another compound to bind a metal. The
sorbent is selected to interact with the metal-coordinating compound in
sequestering the metal from solution as part of a complexation.
Thereafter, the ligand-metal complex may be removed from the solution.