Microporous polypropylene hollow fiber membranes (HF) impregnated with horseradish peroxidase (HRP) and laccase were used to Study the degradation of selected hydroxylated aromatic compounds (3,4-dimethylphenols, 4-ethylphenol, 2-hydroxy-1,2,3,4tetrahydronaphthalene. 2-hydroxy-decahydronaphthalene and 4-hydroxy-biphenyl). It was found that, with the exception of 2-hydroxy-decahydronaphthalene. all substrates were efficiently degraded (50-100% within 48 h). In preliminary investigations, the transport behavior of the analytes through the membranes before and after enzyme immobilization was studied in batch experiments. In addition, a continuous-flow hollow fiber membrane device was used to examine the degradation performance of the immobilized enzymes on the substrates. It was successfully demonstrated that freshly prepared radish juice can be used to replace the commercially available horseradish peroxidase. The method of overall monitoring used was a combination of solid-phase microextraction/gas chromatography/mass spectrometry (SPME-GC-MS). (C) 2004 Elsevier B.V. All rights reserved.