Plant-based system for abatement of gaseous ammonia contamination of air

摘要

The air in a room can be cleaned of ammonia by passing it through green plants grown hydroponically. The air passes through a falling curtain of droplets of hydroponic water, whereby ammonia goes into solution in the water. Microbes colonised on the roots of the plants break down the ammonia in the hydroponic water. The ammonia containing water is recirculated over the matrix again and again. The device comprises a plant box 23, an air circulation fan 24 and a hydroponic water circulation circuit 25. The plant box comprises a plenum chamber 26 and has an air outlet port 29 in one of the walls 28. Another wall 30 of the plant box comprises a near-vertical matrix panel of porous or fibrous inert material 32 into which plants are rooted. Air is drawn through the panel into the plenum and then through the outlet port by the fan. The hydroponic water circulation circuit comprises a water storage tank 34 from which water is pumped using pump 35 up delivery pipe 36 to water outlet 37. The hydroponic water trickles down the panel, keeping the roots wet. The device freshens stale air in a room, and may be provided as a wall-mounted unit, or as a self standing tower.