A novel static mixer design (screen-type elements) capable of taking advantage of the interfacial characteristics of industrial gas/liquid systems was developed. The interfacial area of contact, and volumetric oxygen transfer coefficient, were investigated using a 25.4mm pipe loop in which liquid superficial velocities of up to 2.0m/s (and gas holdups as high as 0.15) were tested. Volumetric mass transfer coefficients as high as 0.44s(-1) were achieved. The ability of this design to achieve high energy utilization efficiencies is validated by achieving oxygen transfer rate as high as 4.2 kg/kWh in the presence of surfactants. Depending on the process requirements and the interfacial properties of the system, high volumetric oxygen transfer coefficients or high energy utilization efficiencies can be achieved by modifying the contactor design and/or operating conditions. (c) 2005 Published by Elsevier Ltd.