Treatment of model soils contaminated with phenolic endocrine-disrupting chemicals with laccase from Trametes sp. in a rotating reactor

An enzymatic treatment system for the remediation of sand contaminated with endocrine-disrupting chemicals (EDCs) was studied. Laccase from Trametes sp. (Laccase Daiwa) decreased the amounts of nonylphenol, octylphenol, bisphenol A and ethynylestradiol (synthetic estrogen) adsorbed on sea sand (2 μmol g^-1) in a test tube with shaking. The phenolic endocrine-disrupting chemicals might have polymerized via enzymatic conversion to their phenoxy radicals. The optimum pH for the enzymatic treatment was approximately 5. A rotating reactor was used for scaling up the enzymatic treatment. The reaction rate increased by rotating the reactor. The optimum speed of revolution was 10-15 rpm for the treatment of nonylphenol. The amounts of octylphenol, bisphenol A, and ethynylestradiol also decreased enzymatically in the reactor. Our enzymatic treatment system with a rotating reactor will be useful for the treatment of soil highly polluted with phenolic EDCs.