Solvent extraction of pentachlorophenol from contaminated soils using water-ethanol mixtures

Pentachlorophenol (PCP) is a wood preserving agent that is commonly found i n contaminated soils at wood treatment sites. The extraction of PCP from co ntaminated soils was evaluated using water-ethanol mixtures as solvents. A mixed solvent containing equal proportions of water and ethanol, a water-mi scibie mixture, proved effective in extracting PCP from both spiked and fie ld contaminated soils. Maximum PCP recovery from soil occurred within the f irst hour of contact between soil and the mixed solvent. PCP extraction wit h the 50% water-ethanol mixture was comparable to extraction using Soxhlet and sonication procedures. In batch extraction experiments, 50% ethanol was effective in recovering PCP from soils spiked with up to 99 mg/kg PCP. Thi s water-ethanol mixture was as effective as richer ethanol solutions in rem oving PCP from field soils found at a wood preserving site, extracting appr oximately 720 mg/kg PCP from one soil along with hydrocarbons (alkanes and PAHs) present in the field soil. (C) 1999 Elsevier Science Ltd. All rights reserved.