Hazardous industrial waste stabilization using inorganic phosphates: Investigation of possible mechanisms*

摘要: The present study focuses on the use of phosphate-containing compounds, such as apatites, stabilization additives for solid industrial wastes. examined highly toxic waste contained mainly lead, iron, and bromides. Phosphates (synthetic or natural), when used additives, were found to diminish release lead from stabilized below respective legislative concentration limits, following application DIN 38414 stan- dard leaching method within range pH values 7.5-10.5. synthetic compounds PbO Pb(OH)Br, existing also in waste, additionally studied during simulation experiments, order examine possible mechanisms stabilization, by using same (phosphates). obtained results showed pos- sibility another parallel mechanism, different that proposed literature, which is sorption aqueous ions onto apatite surface. It was suggested can be transformed into less soluble phases through interaction (surface crystal- lization) exposed surface with environment. formation new crys- tals phase sufficiently fast, especially case natural phos- phate mineral additive, most probably due presence calcite, supplies part its carbonate content phases.