EFFECT OF ALUMINUM SULFATE AND CATIONIC POLYMER ADDITION IN THE MIXED LIQUOR OF A SUBMERGED MEMBRANE BIOREACTOR (SMBR): SLUDGE CHARACTERISTICS AND ORTHOPHOSPHATE REMOVAL IN BATCH EXPERIMENTS

摘要

Submerged Membranes Bioreactors (SMBR) are an established technology for wastewater treatment for water recovery and reuse. However, its routine application is still compromised by the high energy consumption to overcome the fouling effect. This study evaluated the effect of aluminum sulfate and cationic polymer in the orthophosphate removal and sludge filterability improvement in the mixed liquor of a SMBR pilot system. Parameters such as coagulant concentration, filtration time, extracellular polymeric substances (EPS) reduction and orthophosphate removal were evaluated by using a jar-test and a stirred cell. As results, aluminum sulfate and polymer additions improved the filtration index (FI 30 ) from 25% to 32 %, for both chemicals. Time-to-filter (TTF) results evidenced a positive and significant correlation between aluminum sulfate dosage and colloidal EPS reduction.