In frame of proposed project, breakup of fluid particles (bubbles and drops) in a turbulent liquid flow will be studied. The probability of particle breakup and size distribution of daughter particles will be established. It will be tested how the breakup process is affected by presence of surfactants in the system. Experiments will be carried out in a channel, in which turbulent energy can be controlled. Velocity field and turbulence characteristics will be measured using PIV. The particle breakup will be recorded by meas of high-speed camera. The experiment will allow to determine the breakup frequency and the size distribution of daughter particles in dependence on local mean shear, turbulence properties (k, ε) and on properties of bubble or drop interface. The final result should be the validation of current models for particle breakup or a new model, useable as breakup kernel in Population Blance Modelling (PBM) simulations.