This study aims to find a new die purification for wastewater reuse. It consists of the filterability of biological sludge exits of the wastewater treatment plant at Staoueli (Algeria) on porous membranes. The membrane used is a mineral membrane M2 Carbosep (15 Kg/mol). we are interested for the first time in the influence of the transmembrane pressure on the permeate flux for various concentrations in biomass where we deduced that it is necessary to work with transmembrane pressures lower or equal to I bar, because in this field the membrane fouling is minimum and in the second time, we considered the different parameters of evolution (the permeate flux J(v), the turbidity, the biological oxygen demand (BOD5), and the chemical oxygen demand (COD)) for various concentrations in biomass according to time. This process showed good performance in removing the chemical oxygen demand 97.7% for a concentration in biomass of 50g/L and in removing biological oxygen demand 98.8%.