This paper aims to investigate the three-phase equilibriums to design a bioreactor to degrade trichloroethylene (TCE) and tetrachloroethylene (PCE) by the white-rot fungus Trametes versicolor. The vapour-liquid equilibrium constants were obtained from bibliographic values and these values are 0.392 for TCE and 0.723 for PCE, which show that these two compounds are very volatile. Adsorption of TCE and PCE by dead biomass pellets was studied. Due to the low concentration range studied for both compounds, the linear equation is enough to describe the adsorption equilibrium. The adsorption parameters are 0.110 and 0.176 for TCE and PCE, respectively. Then the equilibrium information obtained was used to calculate the distribution of these contaminants in a three-phase bioreactor in specific degradation conditions and despite it is checked that adsorption is not very high, it is significant (between 12.0% and 12.8%). Moreover, a comparison between TCE and PCE experimental and calculated degradation yields was done to validate the linear isotherm. (C) 2008 Elsevier B.V. All rights reserved.