BACKGROUND: The presence of sugar and lignin degradation products, viz. furans and phenolics, make the acid hydrolysate toxic to the microbes. This work attempts to develop an efficient method for the abatement of these microbial inhibitors at pilot scale. RESULT: Among various methods for detoxifying fermentation inhibitors from acid hydrolysate of Prosopis juliflora, activated charcoal (2.0%) removed inhibitors almost completely, followed by ion-exchange resins (73% phenolics and 84% furans). The neutralization and alkalinization treatments removed specifically furans and caused higher loss of sugars (similar to 50%), while the enzymatic treatment was more effective on removal of furans. The charcoal detoxification process on scale up (20 L), achieved the abatement of 87-93% phenolics and 87-96% furans from acid hydrolysate. The activated charcoal was regenerated and use of regenerated charcoal removed phenolics and furfurals from acid hydrolysate of P. juliflora by 83% and 86%, respectively. The detoxified hydrolysate on fermentation with Pichia stipitis NCIM 3499 produced 6.85 g L-1 ethanol with 0.35 g g(-1) yield and 0.43 g L-1 h(-1) productivity. CONCLUSION: Activated charcoal adsorption was found to be the most effective and cheap method for abatement of inhibitors. Moreover, regeneration of charcoal and the scalability of the process make it industrially competitive. (C) 2015 Society of Chemical Industry