Remediation of Landfill Leachates with the Use of Modified Ashes from Municipal Sewage Sludge

Abstract

The paper presents investigations into the possibility of using sewage sludge ashes in the process of removal of selected contaminants from landfill leachate. A series of tests was carried out for that purpose using leachate from the Promnik landfill in the Świętokrzyskie Province, Poland. The used sewage sludge ash was obtained by incineration of sewage sludge in laboratory conditions. Additional tests were conducted for sewage sludge ash, which was modified by zeolitization with a fusion method. This modified ash contained zeolite X. The tests were carried out in the process times of 10, 20, 30, 60, 120, 180 and 240 min. Chemical oxygen demand (COD) and selected elements including metals (Cu, Cr, Ni, Pb, Fe, Mg, Zn, Ca, Na, K) were determined in leachate, before and after the treatment process. Furthermore, the following quantities were measured: pH, potential, conductivity, colour and dissolved organic compound (UV254). All analyses performed were compliant with the binding standards. It was observed that ashes used in the experiment proved effective for copper and lead removal from leachate samples. It was shown that the modified ash turned out to be as effective as the ash, which was not subjected to zeolitization with the fusion method. The modified ash of concern can also be used for the removal of organic compounds from landfill leachate.