Abstract:
In this research, the treatment of wastewater from high-rise building was done to upgrade the treated water quality for gardening. This study was focused on the effect of intermittent aeration time (on/off aeration) on the remove performance for organic carbon, nitrogen and phosphorus by Oxidation-Ditch Membrane Bioreactor (OD-MBR). The intermittent aeration time of OD-MBR in this experiment was varied to : continuous aeration, 60/60, 40/80 30/90, 80/40 and 90/30 minutes. This research can be divided into 4 parts. They were membrane fouling, organic carbon (COD), nitrogen (TKN) and phosphorus (PO43-) removal efficiencies, the effluent quality and the cost evaluation of the system operation. The result shows that the main cause of clogging into pore and fouling on membrane surface of the membrane on OD-MBR system is related to the sludge floc which was pin floc, having size smaller than 57 µm and extracellular polymeric substances (EPS), consisting of proteins and polysaccharides that can be determined by SEM and FT-IR techniques. The highest COD, TKN and PO43- removal efficiencies could be achieved at 88.7%, 81.8% and 37.2% respectively. Moreover, from the treatment cost evaluation for the intermittent aeration mode (on/off aeration) it indicates that the intermittent aeration could consume less energy than the continuous aeration system. Therefore, it can be summarized that the intermittent aeration of 30/90 minute was the most efficiency to remove organic carbon, nitrogen and phosphorus, as well as energy saving in operating the OD-MBR system.