The modification of activated carbon powder (ACP) with ferreous sulfate and the degradation of sodium dodecyl benzene sulfonate (SDBS) under microwave irradiation combined with the modified ACP were studied in this work. The research results showed that the catalytic activity of the modified ACP depended on the concentration and acidity of ferreous sulfate solution as well as immersing time. Also, the influences of irradiation time, initial concentration and acidity of SDBS solution and addition amount of modified ACP on the degradation were assessed. UV-vis spectra. FT-IR spectra, ionic chromatography, HPLC and TOC technologies were brought to bear in assessing the modification and the degradation processes. For modified ACP, under given conditions such as 100 mg/L SDBS solution, 1.20 g/L catalyst dose and pH = 6.0, a high degradation ratio (75.5%) was obtained for 25 mL solution within 90 s microwave irradiation, while it was only 59.59% for unmodified ACP. Furthermore, the degradation ratios Could reach 100% by the appropriate increase of addition dose (e.g. 2.80 g/L) of modified ACP or the extension of irradiation time (e.g. 230 s). Whereas, for unmodified ACP, the corresponding degradation ratios were only 88.71% or 83.54%, respectively. Hence, it can be concluded that the method adopting microwave irradiation combined with the modified ACP reveals many advantages of rapid degradation rate, low cost, no residual intermediates and no secondary pollution in actual application. (C) 2009 Elsevier B.V. All rights reserved.