This proposal addresses the environmentally important task of removing certain hazardous small organic molecules (e.g. aromatic amines, PCBs and polycyclic aromatics) from water by a unique process utilizing enzyme catalysis in an organic phase. In this process, the aqueous phase is separated from in organic phase by a membrane. The enzyme is dissolved in the organic phase, and the membrane is selected to have a cutoff pore size so that the hazardous small organic molecule, but not the enzyme, can pass through the membrane. The organic molecule diffuses into the organic compartment where the enzyme polymerizes the organic into a high molecular weight species which can subsequently by removed from the organic phase via settling or ultrafiltration. To demonstrate the feasibility of this process, 2 chlorophenol (2CP) will be used as the example organic solvent, and the polymerization will take place in perfluorodecalin with horseradish peroxidase as the enzyme catalyst. This catalysis requires free radicals which will be provided by hydrogen peroxide, itself generated by alcohol oxidation catalyzed by alcohol oxidase.