Simultaneous adsorption and biodegradation process in fluidized biobarrier reactor is one of emerging methods for eliminating surfactant in waste water. This paper discusses the adsorption process on activated carbon as a part of a biobarrier system. Surfactant used in these experiments is branched sodium dodecyl benzene sulfonate branched in various concentrations of 400, 700, 1000 and 1500 mg/L placed in 250 mL closed-erlenmeyer container (in batch system). Adsorption took part in a glass column of 30 cm length and 2 cm diameter. Total surfactant concentration was measured with COD-chromate analysis and surface tension measurement. Adsorption equilibrium curves in solid (dC/m) and liquid phase (Ce) as well as surfactant concentration versus surface tension were performed. The results showed that surfactant adsorption equilibrium curve rose within equilibrium concentration (Ce) 0 – 533.4 mg/L, then reached plateau with increasing Ce. Critical Micelle Concentration (CMC) Sodium Dodecyl Benzene Sulfonate was 533.4 mg/L. Freundlich equilibrium constants were (1/n) = 1.91 and Kf = 9.97.10-5 in Ce range of 252.6 to 481.2 mg/L. The equilibrium time for adsorption was 24 hours and the minimum fluidization velocity was predicted to be 0.717 cm/s