This study is aimed at developing a strategy for acid blue 74 dye (ab74) removal from synthetic water by activated sludge supported onto activated carbon. Low cost ecofriendly adsorbent has been investigated as alternative to expensive methods for removing dyes. Bacterial laccases have been found from activated sludge; however, their contribution has yet not been quantified. Activated sludge (AS), sludge with certain grade of permeability (PS) and sludge supported onto activated carbon (ACAS) were used to evaluate their capacity to discolor ab74. The zymogram and the oxidation of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) confirmed the presence of laccases either AS or PS. Inhibition assays also evidenced the contribution of laccases to discolor ab74; achieving discoloration of 23.2 % and 19.09 % for AS and PS, respectively. The discoloration of ab74 was found to be most effective in the ACAS cultures than AS and PS. ACAS displayed an interesting synergic effect for ab74 discoloration of 76.6±11 % of efficiency and specific discoloration rate of 5.9±0.4 mg ab74 /h gtreatment. A novel insight is that the activated sludge was able to regenerate in situ the adsorption capacity of the activated carbon; these results are promising to be applied in wastewater treatment technologies.