Mechanochemical remediation of heavy metals contaminated soils: modelling and experiments

The use of mechanochemistry for the remediation of heavy metals contaminated soils is investigated. Specifically, synthetic sandy soils contaminated by Cd(II), Pb(II) and Zn(II) are prepared. The degree of metal immobilization is evaluated after the soil is subjected to mechanical treatment by analyzing the leachable fraction of heavy metals obtained through the “synthetic precipitation leaching procedure (SPLP)”. For the case of soils contaminated by heavy metals concentration levels similar to field contaminated soils, their leachability is reduced to levels lower than the USEPA regulatory threshold for drinkable water. In addition impact velocity of milling media as well as impact energy and frequency are evaluated by means of a simulation model of the used milling apparatus.