Treatment and recovery of contaminated railway ballast

Experimental tests of metal extraction from stones sampled from articially contaminated railway ballasts\udare presented and discussed. Metal extraction was performed by washing with aqueous solutions of disodium ethylenediaminetetraacetate\ud(EDTA), at selected concentrations. The eectiveness of the remediation process was evaluated using\udleaching tests.\udThe results indicate that the washing technology represents a successful and aordable solution for the implementation\udof an on-site treatment aimed at a reuse process. Adopting a 0.05 M EDTA solution, extraction yields in the\udrange between 40% and 70% were achieved, depending on contact time and pH of the washing solution