Compressive Strength and Leaching of Lead in Solidified Battery Waste Sludge using Calcium Carbide Waste and Rice Husk Ash

摘要

Alternative uses of hazardous waste have been intensively studied. The aim of this research was to determine the compressive strength and amount of lead leached from solidified battery waste sludge using calcium carbide waste (CCW) and rice husk ash (RHA) as the cementitious binders in solidification. The CCW : RHA binder was tested at mixing ratios and curing times. Results indicated that the optimum ratio of CCW and RHA for the solidified sludge was 0.4:0.6. When the ratio of sludge of 0.25 was used in the solidification, increase of strength in solidified sludge significantly differed as the curing times increased (p0.05). The linear relationship between the development of strength and curing time in solidified sludge was observed. The maximum compressive strength of solidified sludge exhibited at 23.58 ± 1.438 kg/cm2 in 28-day curing. In addition, the highest leaching of lead in solidified sludge with ratio of sludge of 0.25 was found at 2.657 ± 0.036 mg/L in 21-day curing. The optimum ratio of CCW : RHA : sand : w/b ratio : sludge was (0.4:0.6):(2.75):(0.65):(0.25) which provided a compressive strength and the amount of lead leached that met the regulatory limit of Ministry of Industry, Thailand.