Politetcnico di Milano - Dipartimento di Ingegneria Idraulica, Ambientale, Infrastrutture Viarie, Rilevamento
Abstract
A reactive barrier (RB) of transformed red mud (TRM), a by-product of the refinement
of bauxite in alumina production, was fitted adjacent to the anode of an electrokinetic (EK) system
with the aim of enhancing removal and favouring entrapment of chromium added to a low
permeability clayey soil. The innovative study focused on evaluation of the synergic interaction
between the EK system and the RB, and of efficiency when compared to traditional EK
remediation. The results obtained underlined the successful outcome of treatment. In presence of
the TRM RB, 19.4% wt. of total Cr content was detected in the anolyte and 20.6% wt. trapped in
the anodic RB after 6 days, versus 6.6% wt. in the anolyte and 8.8% wt. in the soil adjacent to the
anode following the control run without RB. On increasing duration of treatment up to 12 days,
60.8% wt. of total initial Cr was found in the anolyte and 25.5% wt. trapped in the RB, versus 9.1%
wt. and 5.3% wt., respectively, after a control run of the same duration. Finally, on increasing the
mass of TRM in the RB, 60.6% wt. of initial Cr content was found to have accumulated in the RB,
with Cr being completely absent from the anodic chamber
