Assessment of coagulation-ultrafiltration performance for the treatment of primary wastewater using alum sludge
Résumé
The main purpose of this research was to develop an effective and inexpensive pretreatment for ultrafiltration (UF) membrane process in order to treat a primary effluent for its reuse in several applications by avoiding biological treatment. For that the impacts of reuse alum sludge liquid recovered by the drinking water treatment plant of Boudouaou (Algiers area) has been examined on the water quality in coagulation-sedimentation processes. The tests were carried out on a primary effluent of wastewater treatment plant. The elemental analysis by x-ray fluorescence showed that the tested sludge is composed mainly of Al2O3 (41%) and SiO2 (44%). The efficiency of alum sludge as primary coagulant was compared with a conventional metal-ion coagulant (fresh alum) using a jar test apparatus for simultaneous removals of turbidity, UV254 and chemical oxygen demand (COD). For dose of 30 mg Al/L, the sludge was effective as primary coagulant for removing the turbidity, COD and UV254.