Utilization of Carbonized Sewage Sludge in Preventing Heavy Metal Leakage from Landfill sites

Abstract

Although landfills are the primary method of waste disposal, a leakage of water from the landfill site could cause an environmental pollution. A carbonization technique was recently developed to reduce volumes of sewage sludge; however, carbonized sludge is of limited use. In this study, the usage of carbonized sewage sludge is proposed to prevent pollutants from leaking out of landfills. To confirm this hypothesis, zinc solutions under various pH were used as modified heavy metal-containing leachate. It was found that the carbonized sewage sludge not only neutralized the acidic leachate solution, but also phosphates released from the sludge reacted with heavy metals to form insoluble materials. These experimental results were also assessed on the basis of chemical equilibrium. It was suggested that the usage of carbonized pellets as in landfill site was possible to minimize the environmental pollution by heavy metals leached from landfill.