Abstract
The removal of phenolic compounds by using peroxidase of pak-bung (Ipomoea aquatica) was studied for an effective utilization of pak-bung which can be harvested in great quantities as the by-product of channel flow type wastewater treatment process. Peroxidase activities of pak-bung in leaf, stem and root portions were revealed to be 26.9, 28.1 and 44.6 U·g-1 wet weight, respectively. Crude peroxidase extract could be easily prepared by homogenizing pak-bung tissue with tap water. Peroxidase activity of this crude extract could be maintained with only 10% reduction of its activity at storage temperature of -80°C. Optimum treatment condition for phenol solution of 100mg·l-1 was experimentally determined to be as follows; initial pH =5.0, initial H2O2 concentration 2.5mM, initial peroxidase activity 0.3U·ml-1 and reaction time 5 hours. Phenol removal efficiency became higher through divided addition of H2O2, owing to less inactivation of Peroxidase by H2O2. Peroxidase crude extract could also remove 1-naphthol and 8-hydroxyquinoline at removal efficiency over 95%. Moreover, peroxidase crude extract was shown to remove phenol in diluted industrial phenolic wastewater (ca. 1, 000 mg-phenol·l-1) at about 85%.
