ZERO EMISSION; AN OPTIMUM WASTEWATER TREATMENT SYSTEM

The Hanshin Water Supply Authority (HWSA) has introduced effective wastewater treatment system to its New Amagasaki water treatment plant (WTP) with the objective of strengthening water quality management, dewatering process improvement, and cake volume reduction. As for the water quality management, turbidity particles including microorganisms in filter backwash water are separated by dissolved air floatation (DAF), and removed from the washwater reclamation system. The exhaust heat energy from the natural gas co-generation system installed into the WTP is used for heating sludge and drying dewatered cake. Heating sludge improves dewaterability and reduces power consumption. It is possible to extend re-utilization field of the cake by heating the dewatered cake into pelletized one, which leads to complete recycling; zero emission. Wastewater treatment system at the plant could reduce microbial risk and environmental load, while decreasing operation and maintenance cost by about 15%.