Abstract:Wastewater from ABS condensation drying section was treated by biological activated carbon (BAC) and activated carbon without bacteria. The bioregeneration occurring during simultaneous adsorption-biodegradation processes was studied seriously. The organic nitriles and aromatic compouds could be decomposed and transformed, and the removal efficiencies of COD, TOC and Org-N were all more than 80%. The organic nitrogen of ABS wastewater could be transformed into NH3-N, and its transformation efficency was more than 65%. There were a large number of microorganisms on the surface of activated carbon in the BAC, such as long-stem bacteria, vorticella and coccises. The activated carbon provided an attachment surface for microorganisms and protected them from shock loadings of toxic and inhibitory materials, whereas microorganisms bioregenerated the activated carbon.