A concept of the membrane CTF reactor and the possibility of using it for gas-liquid (slurry) processes has been presented. A modified CTF reactor with rotating shaft replaced by a static helicoidal ribbon guide was proposed. The effects of such parameters as the gas-liquid mixture mass flow rate, the ratio of volumetric flow rates of the phases: gas/liquid, a rotational speed of the internal cylinder on the mass transfer in a two-phase system was determined experimentally. The influence of the liquid viscosity increase on the values of the volumetric mass transfer coefficients have been investigated. Experiments indicated high values of the mass transfer coefficient (k(L)a being of the order of 10(-1) s(-1)), particularly in a high viscosity liquid. A possibility to use CTF reactor in the wet air oxidation process for slurry and sludge wastes treating.