In this study we evaluated the feasibility of two regeneration strategies of contaminated polymers
employed for ex-situ soil remediation in a two-step process. Soil decontamination is achieved by sorption
of the pollutants on the polymer beads, which are regenerated in a subsequent step. Tested soil was
contaminated with a mixture of 4-chlorophenol and pentachlorophenol, and a commercial polymer,
Hytrel, has been employed for extraction. Removal efficiencies of the polymer-soil extraction are in the
range of 51e97% for a contact time 24 h. Two polymer regeneration strategies, solvent extraction and
biological regeneration (realized in a two-phase partitioning bioreactor), were tested and compared.
Performance was assessed in terms of removal rates and efficiencies and an economic analysis based on
the operating costs has been performed. Results demonstrated the feasibility of both regeneration
strategies, but the bioregeneration was advantageous in that provided the biodegradation of the contaminants
desorbed from the polymer. Practically complete removal for 4-chlorophenol and up to 85%
biodegradation efficiency for pentachlorophenol were achieved. Instead, in the solvent extraction, a
relevant production (184e831 L kgpol
1) of a highly polluted stream to be treated or disposed of is
observed. The cost analysis of the two strategies showed that the bioregeneration is much more
convenient with operating costs of ~12 V/kgpol i.e. more than one order of magnitude lower in comparison
to ~233 V/kgpol of the solvent extraction.