Abstract: An electrolytic process and apparatus purifies contaminated bulk aqueous solutions and remediates soil. The apparatus is an electrolytic treatment or remediation unit consisting of one or more electrolytic cells having a cathode chamber separated from at least one anode chamber by a separation membrane. The cathode chamber has cathode plates positioned at an angle to the perpendicular or vertical axis of the cell made of valve metals with an irreducible oxide coating. Non-turbulent flow of the solution in an interfacial zone adjacent to the cathode is controlled by the evolution of hydrogen during electrolysis, resulting in a steady state flow of colloidal particles and cations in the cathode-solution interface sufficient to collapse the Gouy-Chapman layer, thereby causing total and irreversible agglomeration of all colloidal particles. A separation membrane separates cathode and anode chambers and allows conductivity driven ionic transfers, and prevents electro-osmotic reflux of the anolyte.

Abstract: A method of processing an aqueous feed liquid to precipitate at least one metal (e.g., copper, nickel or a combination thereof) in a form to make the metal subsequently removable from the feed liquid by filtration, comprises the initial step of mixing (i) an aqueous feed liquid containing a soluble salt of the metal to be removed, (ii) oxalic acid in excess of that required to react with metal, and (iii) a pH-adjusting liquid in a quantity sufficient to lower the pH of the feed liquid to a point between that at which the feed liquid becomes slightly supersaturated with respect to the oxalate of the metal and that at which precipitation of the metal oxalate is initiated. The mixture is then allowed to stand (either at room temperature or heated to elevated temperatures) for a period of time sufficient to form metal oxalate, and finally the formed metal oxalate is separated from the feed liquid to leave an aqueous liquid suitable for discharge to a sewer line.