Wet air oxidation process using recycled copper catalyst

A catalytic wet oxidation system comprising:

• a wet oxidation unit;
• a source of an aqueous mixture comprising at least one undesirable constituent fluidly connected to the wet oxidation unit;
• a source of copper catalyst soluble in the aqueous mixture fluidly connected to the aqueous mixture, the aqueous mixture desired to have a solubility pH at which the catalyst is substantially soluble, the solubility pH being below about 4 or above about 12;
• a first pH sensor configured to detect a pH level of the aqueous mixture;
• a pH controller in communication with the first pH sensor configured to generate a first control signal to adjust the pH level of the aqueous mixture to the solubility pH of below about 4 or above about 12 for treatment of the at least one undesirable constituent in the wet oxidation reactor in response to the first pH sensor registering a pH level above about 4 or below about 12;
• and
• a second sensor in communication with the controller, the second sensor configured to detect a pH level of an oxidized aqueous mixture formed in the wet oxidation unit, the pH controller configured to generate a second control signal to adjust the pH level of the oxidized aqueous mixture to a second range at which the catalyst is substantially insoluble downstream of the wet oxidation unit.