Lime and Lignite Fly Ash as Cement Replacement in Hazardous Waste Solidification Process: Case Study of Spent Fluorescent Lamp

Abstract

The main objective of this research is aimed at the usage of lignite fly ash (power plant) and lime as cement replacement in hazardous - waste solidification process of spent fluorescent lamp. The study found that the increasing of waste ratio in solidification process has the trend to increase density and mercury leaching concentration. Different binder ratios and waste ratios produced different strength effects on the solidified sample. Mercury leaching concentration decreased with increasing curing times, whereas the density and the strength trend to decrease after 14 days. In consideration the properties of solidified sample and cost of solidifying material, a ratio of cement to lime to fly ash of 0:30:70 was found to be the most optimum ratio for solidifying spent fluorescent lamps (at a ratio of spent fluorescent lamp to binder of 2:1), with curing time more than 7-days. Accordingly, it is reasonable to assume lime and lignite fly ash are considerably better for use as a cement replacement alternative for spent fluorescent lamp solidification.