Filterability of biological sludge on porous membranes

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 1 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 Jv, 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 %.

The results obtained showed that ultrafiltration is an interesting process. The comparison between the analysis results of traditional purification (BOD5 = 30 mg/L, COD = 90 mg/L) and that using the ultrafiltration of biological sludge makes it possible to notice that the latter is better efficient. The decrease of the COD and the BOD5 in the course of time is due to the rejection of foulant by the membrane CARBOSEP M2 which formed a fouling cake on the membrane surface. In addition, the permeate obtained is of very good quality from the physicochemical and bac- COD (mg/L) COD (Initial) COD (Final) MLSS=5g/L MLSS=10g/L MLSS=20g/L MLSS=30g/L MLSS=50g/L Fig. 6. Variation of the COD for different concentrations of biomass.