Utilization of Byproduct Sulfur for Chromium Waste Treatment

Abstract

Sulfur-based treatment technologies have been the focus of an increasing number of research studies and commercial applications for treating soils and groundwater contaminated with toxic metals. Calcium polysulfide reduces and precipitates some highly soluble metals such as arsenic, lead, copper, and zinc to form metal sulfides, which often are much less soluble than metal hydroxides and remain insoluble within a wider range of pH values. In addition to their ability to immobilize and degrade hazardous wastes, modified sulfur products can be used as binders in solidification/stabilization treatment of hazardous wastes. One of the modified sulfur products that can be used for that purpose is called plasticized sulfur. Plasticized sulfur is made by heating elemental sulfur to the point where it becomes a viscous fluid. At that point hydrocarbon plasticizers are added to maintain a semi-solid consistency of the sulfur as the temperature returns to normal levels. Plasticized sulfur has recently emerged as a possible alternative binding and stabilizing agent for the solidification and stabilization of hazardous, low-level radioactive and mixed wastes. Plasticized sulfur has been used as a binder for solidification/stabilization of wastes contaminated with heavy metals, elemental mercury waste and a variety of mixed wastes.