Efficiency of composite permeable reactive barriers for the removal of Cr(VI) from leachates
(EN)
Κομνιτσας Κωνσταντινος
(EL)
Μπαζδανης Γεωργιος
(EL)
Bazdanis Georgios
(EN)
Komnitsas Konstantinos
(EN)
Bartzas Georgios
(EN)
Πολυτεχνείο Κρήτης
(EL)
Technical University of Crete
(EN)
The present paper uses a novel approach and aims to assess the efficiency of composite permeable reactive barriers (PRBs) containing organic material and elemental sulphur for the clean-up of leachates containing Cr(VI) and acetate. The paper also aims to identify the main mechanisms involved in the removal of Cr(VI). Experiments were carried out in laboratory plexiglas columns, with a diameter of 5 cm and length of 50 cm. The feed contained 10 mg L−1Cr(VI) and chemical oxygen demand (0.6 or 6 g L−1). Under the optimum experimental set-up, the PRB exhibited over a period of 270 d excellent Cr(VI) decontamination potential. X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry as well as Fourier transform infrared spectroscopy were used to characterize the exhausted reactive material, identify newly formed mineral phases and elucidate Cr(VI) removal mechanisms. Sorption of the reduced Cr(III) on the organic material as well as precipitation, mainly as Cr(OH)3, are the main Cr(VI) removal mechanisms.
(EN)
