Detoxification of pentachlorophenol and creosote contaminated groundwater by physical extraction: chemical and biological assessment

Abstract

Chemical analyses revealed that polycyclic aromatic hydrocarbons (PAHs) and other organic compounds were present in a perennial freshwater stream that flowed through the abandoned American Creosote Works and into Pensacola Bay, Florida. Moreover, groundwater pumped from a well depth of 21 m at a location adjacent to the site was heavily contaminated with PAHs and other organics. A study was conducted to determine the efficacy of ultrafiltration for removal of organics from groundwater at this U.S. Environmental Protection Agency, Super Fund site. Ultrafiltration reduced the concentration of total identified organics from 210.0 mg/L in groundwater to 1.5 mg/L in the post-filtration permeate. Tests for toxicity/teratogenicity in embryonic inland silversides, Menidia beryllina; and Microtox 15 min EC50's were conducted with: 1) streamwater, 2) untreated groundwater, 3) feedwater used in the ultrafiltration system and 4) permeate water that passed through the ultrafiltration system. A concentration of 100% streamwater caused significant (alpha less than or equal to 0.05) teratogenic responses in fish embryos and larvae; the Microtox EC50 was 3.7% streamwater. Groundwater and feedwater caused significant embryo toxic or teratogenic responses at concentrations of 100, 10, and 1%; the Microtox EC50's were 0.85 and 0.48%, respectively. In contrast, only 100% permeate water caused significant increases in terata, compared to the control response; at 10 and 1% concentrations greater than 90% of hatched larvae appeared normal. The Microtox EC50 was 30% permeate water.