Water, energy and usable space are three of the major resource issues facing the world today. While water treatment consumes a comparatively small amount of energy, wastewater treatment is a substantial energy consumer in the urban water cycle.The most typical current arrangement of key unit processes in a wastewater treatment plant has preliminary treatment, primary clarification, the aerobic process (often one variant or another of the activated sludge process), and thereafter secondary clarification before discharge of the treated effluent. In the United States, wastewater treatment accounts for about 3% of the U.S. electrical energy load, similar to that in other developed countries. The energy needs for a typical domestic wastewater treatment plant employing aerobic activated sludge treatment and anaerobic sludge digestion is 0.6 kWh/m3 of wastewater treated, about half of which is for electrical energy to supply air for the aeration basins. Therefore, this presentation discuss the possible paradigm shift of wastewater reclamation in the post era of activated sludge process.