Electrocoagulation method with iron electrode is used to treat the industrial textile wastewater in batch reactor. The effects of operating parameters such as time and potential electrolysis on the decolourization and COD removal efficiency have been investigated. The results indicate that electrocoagulation is very efficient and able to achieve 100% colour and 84% COD removal in 3 min at potential 600 mV. The effluent wastewater is very clear and its quality exceed the direct discharge standard. Furthermore, the mechanism of electrocoagulation is elucidated by zeta potential measurement. (c) 2005 Elsevier B.V. All rights reserved.