During this training course, I study in the Microgravity Labotory at the Castelldefels School of Technology (EPSC) of the Technical University of Catalonia (UPC). Today, the NASA turns on the conquest of the Moon. It is for it that studies are made so that the man can live in this new environment. The problem of the waste is then evoked, because the Moon having a gravity much lower than ours, sorting of the waste will raise problem. Furthermore, it is necessary to know that without gravity (or little, as the case of the Moon), all which is solid and liquid do not part in a homogeneous way as we can see it on Earth. So, my study bases itself on the separation of sediments in a fluid. Thus, the work have consisted on studying the effects of the acoustic wave on bubbles and particles. The influence of the acoustic wave on the bubbles and the particles has been studied for a long time by many researchers.