This report describes the use of dynamic membranes for the treatment of bleach effluents. The problem sencountered with bleach effluent and their possible treatment by UF are briefly presented.The results concern the performance of Zr (IV), Si (IV) and composite Si (IV) dynamic membranes in a laboratoy batch cell. The most successfull membrane obtained for 3C+E1 effluent treatment is a Si (IV) membrane formed on a polysulfone support; it exhibits a flow of 30 l/m2.h at 200 psi, with a reeduction of 96 % of color, 86 % of COD, 15 % of chloride adn 99 % of blea