Comparison of biological activated carbon (BAC) and membrane bioreactor (MBR) for pollutants removal in drinking water treatment

摘要

Biological activated carbon (BAC) and membrane bioreactor (MBR) were systematically comparednfor the drinking water treatment from slightly polluted raw water under the same hydraulicnretention time (HRT) of 0.5 h. MBR exhibited excellent turbidity removal capacity due to thenseparation of the membrane; while only 60% of influent turbidity was intercepted by BAC. Perfectnnitrification was achieved by MBR with the 89% reduction in ammonia; by contrast, BAC onlyneliminated a moderate amount of influent ammonia (by 54.5%). However, BAC was able tonremove more dissolved organic matter (DOM, especially for organic molecules of 3,000 , 500nDaltons) and corresponding disinfection by-product formation potential (DBPFP) in raw water thannMBR. Unfortunately, particulate organic matter (POM) was detected in the BAC effluent. On thenother hand, BAC and MBR displayed essentially the same capacity for biodegradable organicnmatter (BOM) removal. Fractionation of DOM showed that the removal efficiencies of hydrophobicnneutrals, hydrophobic acids, weakly hydrophobic acids and hydrophilic organic matter throughnBAC treatment were 11.7%, 8.8%, 13.9% and 4.8% higher than that through MBR; while MBRnachieved 13.8% higher hydrophobic bases removal as compared with BAC.