Passivation of lead and zinc in contaminated soil by application of granulated red mud

Abstract

With red mud — the waste of alumina refinery was developed to preparate red mud-based particle as remediation material, it was applied to contaminated soil from lead-zinc district and planting leeks was for pot experiments. Sampling at 1,5,10,20,30 days under amount of 0–15% and extracting sequentially, the different phases of lead and zinc were determined. And content of lead and zinc in the leek after 30 days was tested. On that basis, compare trial with applying red mud particles and powder was implemented. Experiment results show that by applying red mud-based particles to lead-zinc contaminated soil, effectiveness of remediation was determined by bio-effective state of lead and zinc to reduce and residual lead and zinc increased. The largest decline of ion-exchange Pb was 44.79% and ion phase Zn 100% reduced. The largest increase of residue Pb and Zn were 72.26%, 45.54%. At the amount of 5%, it showed that joint effects of lead-zinc passivation with combination of photon-remediation and promoted leeks growth. With fixed term extension, ion-exchange phase of lead and zinc increased significantly on the contrary by using red mud powder and the last restored effect of carbonate and residual phase were also not as good as the former in the experiment.