Treatment of contaminated waste water

摘要

A method and apparatus for removing a group of species of metal ions from an aqueous solution to be purified which involves the steps for each species in succession of adjusting the pH of the aqueous solution to a value where hydroxide precipitates of said species in its highest valency state are insoluble, then passing the aqueous solution through an ion state modification cell to raise the valence of the respective species to its highest valency state thus causing the ion specie to form the insoluble hydroxide, then removing the precipitated hydroxide from the aqueous solution by appropriate steps of settling and press filtering. A magnetic field is imposed between the electrodes which improves the efficiency of the ion state modification step.