Calcium Performance in Paper Sludge Ash as Suppressing Material

Paper sludge (PS) ash is a waste material collected from the paper industry, which containing calcium compound. In the previous research, several paper sludge ashes have been tried into coal fly ashes in order to suppress the leaching of trace elements such as As, Se, and B into the environment. The result showed that paper sludge ashes has potential effect in inhibit the leaching of these trace elements because of the calcium contains in the paper sludge ashes. Therefore, this research provide information about the amount of calcium in paper sludge ash as suppressing material. Nine kinds of paper sludge ashes tested into coal fly ash C (FA C) in order to know the ability of each paper sludge ash in suppressing the leaching of trace elements. Inductively coupled plasma (ICP-AES) used to determine the leaching concentration of As, Se, and B. Then, the kind of calcium in paper sludge ashes were analysed by X-ray diffraction (XRD). Thermal gravimetric analysis (TG) used to determinate Ca(OH)2 and CaCO3. The percentage of CaO in paper sludge ashes analysed by combination ethylene glycol, ICP-AES and TG. This research found the kind of PS which most influential for controlling leached out of trace elements.