Leaching of heavy metals under ambient resembling conditions from hydrotreating spent catalysts

► Metals leaching were simulated over a commercial spent hydrotreated catalyst. ► At conditions similar to an environmental situation, leaching of Ni, Mo and V occurs. ► The presence of sulfur and coke species is a key factor for metals leaching. ► Unattended spent hydrotreated catalysts represent a risk for the environment.