A new compact scrubber was designed to remove odorous compounds from WWTPs (named Aquilair Plus (TM), for Compact Reticulated Contactor). Hydrodynamics and mass transfer parameters (Delta P, a, k(L)a and k(G)a) were quantified versus superficial gas and liquid velocities (U-SG and U-SL). This study showed that all these parameters increase with U-SG and U-SL, except for k(G)a which is almost independent of U-SL. Thanks to the lab-study, a half-size industrial pilot plant was designed. First results are encouraging. Finally, an economic study showed that Aquilair Plus (TM) allows a gain of 15-40% compared to traditional packed towers. (c) 2007 Elsevier B.V. All rights reserved.