Simultaneous recovery of metals and destruction of organic species: Cobalt and phthalic acid

In mixed industrial effluent, the presence of metal ions can retard the destruction of organic contaminants, and the efficiency of recovery of the metal is reduced by the presence of organic species. Results are presented for cobalt-phthalic acid in which both those effects occur. An electrochemical cell alone can be used to recover cobalt at pH 4.5 but is not capable of achieving complete mineralization of phthalic acid by anodic oxidation. A photolytic cell atone can achieve the destruction of phthalic acid at an optimum pH of 2.5 but leaves the metal ions in solution. A combined photolytic-electrochemical system using an activated carbon concentrator cathode is described that achieves the rapid simultaneous pH-independent destruction of phthalic acid and recovery of cobalt.