Use of DEAF cellulose adsorbed and crosslinked white radish (Raphanus sativus) peroxidase for the removal of alpha-naphthol in batch and continuous process

DEAE cellulose bound white radish peroxidase was employed for the treatment of wastewater contaminated with a-naphthol in batch as well as in continuous reactor. Immobilized enzyme could effectively remove about 79%, 87%, 65% a-naphthol in stirred batch process at 30 degrees C, 40 degrees C and 50 degrees C after 5 h treatment, respectively. However, its soluble counterpart under similar experimental conditions could remove 73%, 75%, 53% a-naphthol. FTIR spectra of the obtained product showed the occurrence of polymerization reaction involving C-O-C bond, Immobilized WRP could remove 64% a-naphthol in presence of 3.0 mM CdCl2; however, its soluble counterpart oxidized only 44% of the contaminant. Immobilized preparation after its 6th repeated use was able to oxidize 58% alpha-naphthol. Immobilized enzyme present in the column was used for the continuous removal of alpha-naphthol and the column retained 57% alpha-naphthol removal efficiency after one month operation. The absorption spectra of the treated and untreated alpha-naphthol containing wastewater exhibited a marked difference in the absorption at various wavelengths. Hence, the designed column reactor could be used successfully at a large scale for treatment of water contaminated with various aromatic compounds. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.