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

Pentachlorophenol (PCP) is a wood preserving agent that is commonly found in contaminated soils at wood treatment sites. The extraction of PCP from contaminated soils was evaluated using water-ethanol mixtures as solvents. A mixed solvent containing equal proportions of water and ethanol, a water-miscible mixture, proved effective in extracting PCP from both spiked and field contaminated soils. Maximum PCP recovery from soil occurred within the first hour of contact between soil and the mixed solvent. PCP extraction with 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. This water-ethanol mixture was as effective as richer ethanol solutions in removing PCP from field soils found at a wood preserving site, extracting approximately 720 mg/kg PCP from one soil along with hydrocarbons (alkanes and PAHs) present in the field soil.