This paper presents the results of a laboratory scale investigation on the remediation of a soil contaminated by a mixture of organic compounds using a two-step process consisting of stripping and biofiltration. The biofilter was packed with the soil under examination in order to use autochthonous microorganisms. To assess the effects of both temperature and superficial velocity of the air stream on process performance different sets of experimental tests were carried out at two air temperatures (50 and 80 degrees C), and at two superficial air velocities (41.0 and 82.0 m h(-1)), corresponding to apparent air residence times in the biofilter column of 38 and 19s respectively. The stripping rate proves to be inversely correlated with the soil-water partitioning coefficient, while no evident correlation was found with the Henry coefficient. It can therefore be concluded that soil-water partitioning is limited by mass transfer while air-water partitioning reaches equilibrium. Temperature influences both stripping rate in the stripping column and degradation capacity in the biofilter. A stripping temperature of 80 degrees C combined with a biofiltration temperature of WC provides the best process performance. (c) 2007 Society of Chemical Industry.
Integrated air stripping for remediation of soils contaminated by organic compounds
NICOLELLA, CRISTIANO;
2007-01-01
Abstract
This paper presents the results of a laboratory scale investigation on the remediation of a soil contaminated by a mixture of organic compounds using a two-step process consisting of stripping and biofiltration. The biofilter was packed with the soil under examination in order to use autochthonous microorganisms. To assess the effects of both temperature and superficial velocity of the air stream on process performance different sets of experimental tests were carried out at two air temperatures (50 and 80 degrees C), and at two superficial air velocities (41.0 and 82.0 m h(-1)), corresponding to apparent air residence times in the biofilter column of 38 and 19s respectively. The stripping rate proves to be inversely correlated with the soil-water partitioning coefficient, while no evident correlation was found with the Henry coefficient. It can therefore be concluded that soil-water partitioning is limited by mass transfer while air-water partitioning reaches equilibrium. Temperature influences both stripping rate in the stripping column and degradation capacity in the biofilter. A stripping temperature of 80 degrees C combined with a biofiltration temperature of WC provides the best process performance. (c) 2007 Society of Chemical Industry.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
