Scale formation and stabilization of heavy metal in landfill waste layer

Abstract

Heavy metals contained in waste are landfilled after stabilization and insolubilization treatment, but there is concern that they may leach out depending on the environmental conditions. On the other hand, it has been revealed that some of the heavy metals leached from landfill waste are co-precipitated in calcium scale that is formed near the leachate collection drainage pipes where air can easily enter, and are difficult to flow out of the landfill layer with the leachate. However, since calcium scale is a substance that dissolves in acid, there is concern that it will dissolve when it comes into contact with acid rain, and the coprecipitated heavy metals will flow out. Therefore, in this study, we conducted an acid rain exposure test on the scale, examined the possibility of heavy metals flowing out. From the results of this study, it was clarified that there is almost no leachig that exceeds the effluent standard.