Anaerobic treatment of soil wash fluids from a wood preserving site

An integrated system has been developed to remediate soils contaminated wit h pentachlorophenol (PCP) and polycyclic aromatic hydrocarbons (PAHs). This system involves the coupling of two treatment technologies, soil solvent w ashing and anaerobic biotreatment of the extract. Specifically, this study evaluated the effectiveness of the granular activated carbon (GAC) fluidize d-bed reactor to treat a synthetic waste stream of PCP and four PAHs (napht halene, acenaphthene, pyrene, and benzo(b)fluoranthene) under anaerobic con ditions. This waste stream was intended to simulate the wash fluids from a soil washing process treating soils from a wood preserving site. The reacto r achieved a removal efficiency of greater than 99.8% for PCP with conversi on to its dechlorination intermediates ranging from 47% to 77%. Effluent, c arbon extraction, and isotherm data also indicate that naphthalene and acen aphthene were removed from the liquid phase with efficiencies of 86% and 93 %, respectively. Effluent levels of pyrene and benzo(b)fluoranthene were ex tremely low due to the adsorptive capacity of GAC for these compounds. Expe rimental evidence does not suggest that these compounds were chemically tra nsformed within the reactor. (C) 1998 Published by Elsevier Science Ltd. Al l rights reserved.