Background: The wastewater originating from the production of acrylonitrile-butadiene-styrene (ABS) resin is a toxic and refractory industrial wastewater. The purpose of this work is to investigate the characteristics of adsorption and biodegradation of biological activated carbon (BAC) for ABS resin wastewater. Results: More than 80% of chemical oxygen demand (COD), total organic carbon (TOC) and organic nitrogen (Org-N) was removed after the 100th run in BAC with the help of bioregeneration, and the treatment efficiency of BAC was higher than that of adsorption and biodegradation alone. The initial Org-N was mainly transformed into NH4+-N, and the transform efficiency reached 65% after the 100th run. After bioregeneration, the COD and TOC removal efficiencies of BAC reactor reached 88.97% and 86.26%, respectively. The BAC had different bioregeneration efficiencies of 94.41, 64.82, 61.05 and 40.04% for 3, 3-imminodipropiononitrile, 3, 3-oxydipropiononitrile, , -dimethyl-benzylalcohol and acetophenone, respectively, which mainly resulted from the different polarity of the compounds. Conclusion: BAC could protect microorganisms from shock loadings of toxic, refractory and complicated ABS resin wastewater. The mechanism of the organic pollutants removal by BAC consisted of three phases including adsorption, bioregeneration and stability. (c) 2012 Society of Chemical Industry