Hydroponic waste management system in Kapalai Island, Sabah, Malaysia. To prevent the run off of nitrogenrich waste on to the nearby coral reefs, Kapalai resort has set up a hydroponicsbased waste treatment plant that relies on bacterial films and plants to remove the nitrogen from waste water. Waste water and sewage first flows through septic tanks in which solids settle out. Ozone is then used to sterilise the water which is then passed through a series of large plastic vats planted with water hyacinth. The root systems of these plants develop a bacterial film which breaks down any nitrogenous waste in the water allowing it to be reused and pumped into the sea without damaging the nearby coral reefs.
