Stabilization and solidification of lead in contaminated soils

Lead has been identified as one of the greatest threats to human health and is one of the common contaminants in many hazardous wastes. In this study, a surplus (waste) material, i.e., sulfur, was employed as a binder to stabilize/solidify lead contaminated soils. Soil samples were collected from a battery recovery plant, which had high levels of inorganic lead contaminant. Results obtained from the study indicated that sulfur binders can be used to stabilize/solidify inorganic lead contaminated soil which may or may not contain organic compounds. However, control samples, which used portland cement to solidify the same contaminated soils, showed that portland cement was also an effective binder. The potential applications of these solidified matrixes are also discussed. Due to the excellent physical, engineering and chemical leaching characteristics, sulfur solidified wastes could be used as construction fills, such as a subbase course in road pavement construction. Under some circumstances, use of the sulfur stabilization and solidification process will be a viable choice, especially where excess sulfur, recovered from various industrial desulfurization sites, becomes a waste product which requires disposal. The excess (waste) sulfur can be used as a stabilization agent for treating lead contaminated soil locally. Thus the two waste materials can be combined and converted into an environmentally stable material for recycling without having to be deposited in a landfill site. This by itself meets the requirements for being a sustainable technology as favored by the emerging world-wide trend of the economy for the future.