The researchers tested a method called Sequencing Batch Reactor to clean up harmful leachate from a dumpsite in Sri Lanka. They found that this method removed a high percentage of pollutants like COD, BOD, and metals from the leachate. By diluting the leachate with water, they were able to effectively treat it before releasing it back into the environment. This study shows that using a Sequencing Batch Reactor followed by a constructed wetland can help improve the quality of water affected by landfill leachate.