Removal of trace-level toxic oxyanions from aqueous solutions by cocrystallization with chelating hydrogen-bonding ligands

Selenate and selenite oxyanions are crystallized together with sulfate anions using ligands. In this approach, we will take advantage of the tendency of these similar oxyanions to co-precipitate into crystalline solid solutions. Such concomitant removal of sulfate and Se-oxyanions has the benefit of reducing wastewater toxicity from Se removal but softening the effluent water and reducing its tendency to form hard sulfate scales.