Soil washing using cyclodextrins and their recovery by application of electrochemical technology

In this study, the capacity of decontaminated polluted soils, by using the sequence washing with cyclodextrin-electrochemical treatment was evaluated. The initial step of the process involved contacting polluted soil with cyclodextrin to enhance recovery of phenanthrene from soil. The total phenanthrene removal in a washing column with aqueous solutions of 1% hydroxypropyl-β-cyclodextrin attained a value of almost 70% after 6 days. The second step of this operational strategy concerned regeneration of the washing solution via electrochemical phenanthrene degradation. The phenanthrene was almost totally degraded in 1 day and the extracting ability of this treated solution was confirmed. By application of this combined technology, it is possible to recycle the washing solution reducing the consumption of cyclodextrin solutions. Consequently, it has provided an effective and economic treatment of PAHs polluted soil.