Ammonia stripper

A method for removing ammonia from landfill leachate, the method comprising:

• passing a hot gas stream carrying waste heat from a heat source through an economiser to produce high pressure hot water in a hot water circuit;
• passing said high pressure hot water through a boiler connected to a source of water to produce an output of steam;
• providing an ammonia stripper having:
• an upper end;
• a lower end;
• a leachate inlet connected to a leachate flow path, and an ammonia containing gas outlet, at its upper end;
• a leachate discharge outlet connected to a leachate discharge flow path, a steam inlet connected to the first heat exchanger by a conduit, and a forced air inlet, at the lower end;
• and a randomly packed bed between the upper end and the lower end;
• passing a flow of steam and air in one direction through the ammonia stripper and allowing leachate to flow, under the influence of gravity, in the other direction over the packed bed to releases ammonia from the leachate.

A system for removing ammonia from landfill leachate, the system comprising:

• an economiser for producing high pressure hot water in a hot water circuit from heat exchange with a hot gas stream carrying waste heat;
• a boiler, heated by said high pressure hot water for producing steam;
• an ammonia stripper having:
• a leachate inlet connected to a leachate flow path, and an ammonia containing gas outlet, at an upper end thereof;
• a leachate discharge outlet connected to a leachate discharge flow path, a steam inlet connected to the boiler by a conduit, and a forced air inlet, at a lower end thereof;
• and a randomly packed bed between the upper end and the lower end;
• an ammonia containing gas flow path connected to the ammonia containing gas outlet and a condenser disposed within the ammonia containing gas flow path to condense at least some of the water within ammonia containing gas passing therethrough;
• and
• wherein the condenser has an inlet and an outlet in the ammonia containing gas flow path and an inlet and an outlet in the leachate flow path such that, in use, heat exchange between the ammonia containing gas and the leachate condenses water from the ammonia containing gas and preheats the leachate.