RESUMEN
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.
Asunto(s)
Bromuros/líquido cefalorraquídeo , Residuos Peligrosos , Plomo/líquido cefalorraquídeo , Eliminación de Residuos/métodos , Aguas del AlcantarilladoRESUMEN
Lead-rich solid industrial wastes were vitrified by the addition of glass formers in various concentrations, to produce non-toxic vitreous stabilized products that can be freely disposed or used as construction materials. Toxicity of both the as-received industrial solid waste and the stabilized products was determined using standard leaching test procedures. The chemically stable vitreous products were subjected to thermal annealing in order to investigate the extent of crystal separation that could occur during cooling of large pieces of glass. Leaching tests were repeated to investigate the relation between annealing process and chemical stability. X-ray, scanning and transmission electron microscopy techniques were employed to identify the microstructure of stabilized products before and after thermal treatment. Relation between synthesis and processing, chemical stability and microstructure was investigated.