EFFECTS OF ELEVATED TEMPERATURE CURING ON STRENGTH AND LEACHABILITY OF THE SOLIDIFIED WASTES USING LIME AND BHA AS SOLIDIFICATION BINDER
Keywords:
Black husk ash, sodium silicate, thermal activation, strength, leachingAbstract
This work studied the effects of elevated temperature curing on strength and leachability of the solidified wastes. The lime to BHA ratio of 45 : 55 was used as solidification binder. The metalcontaining waste was added to the solidification binders at 10, 30, and 50 wt% by weight of binder. The sample were cured at 40oC and 50oC for 1 day and the followed by room temperature. It was observed that the elevated curing temperature accelerated the dissolution of monosilicate ion [SiO(OH)3 -] and Ca2+ ion from BHA and lime. This resulted in an increase in the rate of strength development at the early ages (1 and 3 days); although a reduction of the strength at later age (28 days) was observed. In addition, the leachability of Pb, Cr, Ni, Cu, Fe, and Zn from the solidified wastes was very low except that of cadmium. This was due to the high buffering capacity of the solidified matrices.
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