The integral method for the analysis of kinetic data was used to describe the removal of carbon dioxide dissolved in the aqueous phase of a tubular photobioreactor by Aphanothece microscopica Nageli. The effects of the carbon dioxide concentration (3, 15, 25, 50 and 62%), light intensity (960, 3000, 6000, 9000 and 11,000 lux) and temperature (21.5, 25, 30, 35 and 38.5 degrees C) were considered using a central composite design, aiming to determine the most efficient system conditions. Response surface methodology showed the importance of the operational parameters of the photobioreactor on the kinetics of carbon dioxide removal, a good fit of the first order kinetic model to the experimental data being obtained. (c) 2007 Elsevier B.V. All rights reserved.