Investigation of wastewater including heavy metal treatment with membrane bioreactor combined with granulated activated carbon

During the study, treatment wastewater including carbon (COD), nitrogen (NH4+-N), and phosphorus (PO4-3-P) and heavy metals with laboratory scale Membrane Bioreactor (MBR) combine with Granular Activated Carbon system was investigated. There are two tanks in MBR system first one is activated sludge system about 10 L and the other one in membrane chamber about 8 L. Activated sludge was transferred Full Scale MBR system from Middle East Technical University. Concentration of MLSS was about 3.5 g/L and it increase around 12 g/L when it reached to steady-state. After steady-state, treatment system was feed by synthetic wastewater including heavy metals, Arsenic, As, Nickel, Ni, Lead, Pb, Zinc, Zn, concentration of each one was about 200 ppb. The study was conducted in two system. In the first system, MBR system was operated in three different fluxes, which were 16, 20 ve 24 L/m2-h. Concentration of COD, NH4+-N and PO4-3-P in the influent were about 550, 80 ve 25 mg/L respectively. The highest treatment was achieved when the flux was 16 L/m2-h. The heavy metal treatment efficiency of MBR system was 10% for As, For other selected metals were more than 90 % and for Ni it was 91%, for Pb it was 96% and for Zn it was 96%. After treatment of MBR system, treated wastewater was collected for GAC treatment. The flowrate of wastewater during the GAC column was arranged 5 mL/min. After GAC removal, extra 35% for COD, 18 % for NH4+-N and 11% for PO4-3-P treatment was achieved. The As removal was increased about 85% after GAC column. Concentrations of other heavy metals, Ni, Pb and Zn, were less than Limit of Detection which was 3 ppb.