Energy Evaluation of Combination Processes for Secondary Effluent Treatment

Water reclamation projects are established all over the world to lighten the water stress or scarcity problem. For choosing water reclamation processes not only water qualities but also energy consumption should be considered. This study evaluated the potential of ozonation and ceramic membrane filtration (CMF) combination processes application for water reuse mainly in terms of energy consumption. Energy consumption was calculated based on running experiences of one pilot plant operated by METAWATER CO., with capacity of 7000 m3/day. Considering both PPCPs and MS2 removal target, ozonation, ozonation+CMF and ozonation +coagulaiton+CMF under 4, 6 mg O3/L dose were potential processes. In order to meet the goal, energy consumption for ozonation was in the range from 0.05 to 0.10 kgCO2/m3. Ozonation +CMF and ozonation+coagulation+CMF consumed higher energy with higher product water quality. It was 0.14-0.19 kgCO2/m3. Considering different requirements of various reuses, which process was better should be evaluated case by case. This study showed significance through presenting basic knowledge to choose suitable technology to gain co-benefit of product water quality and energy consumption in water reclamation field.