Selective removal of lead and bromide from a hazardous industrial solid waste using Limited Acid Demand and Separation Factor at ambient conditions

A detailed methodology is described for the selective removal of lead and bromide content from an industrial toxic solid waste, containing also large quantities of iron. Limited Acid Demand (LAD) was examined in order to avoid the co-dissolution of undesirable constituents. The Separation Factor (SF), which is the concentration ratio of dissolved constituents in the resulting leaching solution after the application of extraction stage, can describe the selective release of lead against iron, according to the variation of major leaching parameters (i.e. the molarity of used acid and the liquid to solid (L/S) ratio). A general equation, describing the overall leaching process was obtained, containing a specific “inhibition constant” and indicating that when the initial stoichiometry of leaching procedure and the applied L/S ratio are known, then the removal of lead can be predicted.