LEACHABILITY OF LEAD FROM AUTO SHREDDER RESIDUES - A CANADIAN PERSPECTIVE

The concentration of the heavy metals; zinc, lead, cadmium, chromium and copper in the solid waste Auto Shredder Residue (ASR) have been measured and their leachability evaluated according to a variety of leaching tests currently employed in North America. The importance of pH and a buffering agent have been identified as key features in determining the leachability of these metals. The results of the study indicate that ASR, while it contains relatively high concentrations of the metals lead (0.28%) and copper (1.11%), when the material is subjected to standardized leaching tests only small quantities of these metals are solubilized and detected in the leachate. In addition, the ASR is capable of absorbing additional quantities of lead ions from solution, with the actual amounts being dependent upon the nature of the lead compounds.