Electrochemical treatment of ammonia in waste-water

Apparatus for diminishing the concentration of ammonium in waste-water, and for disposing of the ammonium as nitrogen gas, wherein:

• the apparatus includes an ammonium-extraction station, which:
• includes a waste-water entry port, for receiving a stream of the waste-water to be treated;
• is operable to extract ammonium out of solution from the waste-water stream;
• includes a treated-water discharge port, for discharging the waste-water stream, now with its dissolved ammonium content reduced, from the apparatus;
• the apparatus includes a body of secondary-water;
• the apparatus includes a secondary-water circuit, comprising water-containment components, which contain the body of secondary-water;
• the apparatus includes an ammonium-transfer station, which is one of the water-containment components of the secondary-water circuit, and which is operable to receive the ammonium extracted from the ammonium-extraction station, and to transfer same into the body of secondary water;
• the apparatus includes an electrolysis station, which is one of the components of the secondary-water circuit;
• the electrolysis station includes an electrolytic cell, which is operable upon being supplied with electrical energy;
• to electrolyse the secondary-water, and to oxidise the ammonium dissolved therein;
• to thermodynamically favour the transformation of the nitrogen component thereof to nitrogen gas;
• the apparatus includes a nitrogen-discharge port, for discharging the resulting nitrogen gas from the electrolysis station;
• the apparatus includes an intermediate tank, which is one of the water-containment components of the secondary-water-circuit;
• the ammonium-transfer station has an ammonium-station-inlet and an ammonium-station-outlet, through which secondary-water respectively enters and leaves the ammonium-transfer station;
• the ammonium-transfer station is so configured that secondary-water in the ammonium-station-outlet is at a higher concentration of dissolved ammonium than secondary-water in the ammonium-station-inlet;
• the electrolysis station has an electrolysis-station-inlet and an electrolysis-station-outlet, through which secondary-water respectively enters and leaves the electrolysis-station;
• the electrolysis station is so configured that secondary water in the electrolysis-station-outlet is at a lower concentration of dissolved ammonium than secondary-water in the electrolysis-station-inlet;
• the secondary-water circuit includes respective conduits that convey secondary water:
• from the ammonium-station-outlet into the intermediate tank;
• from the intermediate tank into the ammonium-station-inlet;
• from the electrolysis-station-outlet into the intermediate tank;
• and
• from the intermediate tank into the electrolysis-station-inlet.