Simulated textile wastewater was degraded using a membraneless electrochemical reactor with immobilized peroxidase on the porous Celite. The optimal current density was 10A m(-2), at which the highest amount of hydrogen (H2O2) could be generated. The decolorization efficiencies of the simulated wastewater using the electrochemical and electroenzymatic methods were 35% and 92%, respectively. Biodegradability, the ratio of 5-day biochemical oxygen demand to chemical oxygen demand (BOD5/COD), was enhanced about 1.88 times when using the electroenzymatic treatment rather than raw wastewater, which could not be achieved by the electrochemical treatment. The toxic unit (TU), calculated using the lethal concentration (LC50) of Daphnia magna (D. Magna), of effluent treated by electroenzymatic method was below 1, whereas those of simulated textile wastewater and effluent treated by electrochemical method were 11.4 and 3.9, respectively. (C) 2008 Elsevier B.V. All rights reserved.