Abstract: To achieve energy efficiency, energy management and optimization works across of the entire waste water treatment plant. Some equipment and processes, such as pumps and air blowers related to aeration tanks are particularly need more energy and afford opportunities for major savings. In this technical study, an analysis regarding improvement of energy efficiency in waste water treatment plant is done by enhancing performance of activated sludge feeding from primary clarified tank to anaerobic digestion. Appropriate optimal design process control and efficient operation of anaerobic digester involves employing proper feeding patterns, short sludge retention time, mixing and recycling and others. The ratio of primary and secondary sludge is taken as an influencing factor as well. The ticker the activated sludge from the primary clarified, the more badges is produced, as indicated by the correlation between gas production and chemical oxygen demand/biochemical oxygen demand mass loading. By increasing total suspended solids concentration of the sludge through thickening, the results showed the volume of gas generation is increasing around 15% of design. As a result, the sludge treatment process is configured to operate efficiently thus reducing the active power of the respective equipment at aeration tank.