Treatment of phenol and cresol contaminated soil

Abstract

Bench-scale experiments investigated the technical feasibility of innovative treatment options to remediate soil contaminated with phenol and cresols. These experiments resulted in full-scale operations which were followed by an additional bench-scale test to remove residuals. The bench-scale treatments explored were passive evaporation, soil washing, and biodegradation. Passive evaporation reduced concentrations of phenol, ortho-cresol, and meta- and para-cresol 58 to 66%, 55 to 80%, and 36 to 43%, respectively, after 3 weeks. In the soil washing tests, alkaline water adjusted to pH 11.5 and hot water at 50°C both showed relative cleaning efficiencies of approximately 100%. Shake-flask biotreatment experiments found that Alcaligenes eutrophus JMP134 degraded phenol and cresol in untreated soil. After bench-scale experiments, a full-scale soil leaching process using water as an extractant removed more than 99.9% of the phenol and 99.7% of the cresols. To degrade oil and grease remaining in the leached soil, soil column biodegradation studies were performed on washed soil from the leach field. In the presence of a nutrient solution, oil and grease degraded rapidly, and residual phenol and cresols were further reduced.