Two strategies for PCB soil remediation: Biodegradation and surfactant extraction

Two strategies for the cleanup of PCB‐contaminated soils are being developed: biodegradation by selected bacteria and extraction with aqueous surfactant solutions. Extensive biodegradation has been demonstrated by Pseudomonas putida strain LB400 in studies with Aroclor‐spiked laboratory soil and soil from a New York State site containing 525 ppm of transformed Aroclor 1242 (depleted of di‐ and trichlorobiphenyls). Solutions of sodium dodecylbenzenesulfonate can extract PCB from soils. A bench‐scale process with four countercurrent stages effected the cleanup of a heavy clayey soil. The PCB was recovered from the surfactant solution by precipitation with calcium chloride, reducing the mass of contaminated material to 3% of the original soil mass.