ABOUT THE CLIENT
MUNICIPAL WASTEWATER IN TAIWAN
The Taoyuan City A7 Water Resources Recycling Center in Taiwan is the first sewage treatment & recycling center in the country to adopt Low-Impact Development (LID) technology. This makes it the first zero-discharge sewage water resources recycling center in Taiwan.
The final effluent meets the government’s defined water standards, which means that the water can be used for cleaning roads, irrigation, landscape as well as being available for various usage in the nearby industrial park. The treatment facilities are fully underground, making room for an ecological landscape park on ground level.
WHAT THE CLIENT NEEDED
STRICT WATER QUALITY STANDARDS
The strict water quality requirements meant that high standards were required for the water treatment design. In addition to the high requirements for general water quality in terms of pH, BOD, and SS – the TOC and NH4-N were requested to be lower than 10 mg/L.
Additionally, the design needed to accommodate water being used in applications such as landscape, washing, toilet flushing, and sprinklers to suppress dust, which needed to meet E. coli discharge requirements of 200 CFU/100mL.
THE SOLUTION
STATE-OF-THE-ART UV DISINFECTION FOR WASTEWATER RECYCLING
The total design flow is 12500CMD with three construction phases. The state-of-the-art Anoxic/Aerobic Membrane Bio-reactor + UV process provides excellent quality for BOD < 5 mg/L, SS <2 mg/L, TOC <5 mg/L, NH4-N < 3 mg/L and E.coli< 100 mg/L.
For the disinfection process, although MBR membrane has the function of rejecting bacteria, this was not sufficient for meeting the disinfection requirements of E.coli <200 CFU/100mL. To solve this, the ULTRAAQUA LOW UVT disinfection systems were conveniently installed directly on the MBR permeate pipeline, using the MBR permeate pump to transfer the water through the UV system.
The LOW UVT UV system was chosen, as it provides excellent disinfection for applications in low UVT environments, being 70% in this instance. The innovative SWIRLFLOW technology makes the LOW UVT able to improve UV exposure, eliminating any chance of ‘dark areas’ with untreated water, resulting in exceptional disinfection and energy efficiency in these environments.
UV design information:
- 2 x MR12-350SS LOW UVT SWIRLFLOW™ (One duty, One standby)
- Peak flow: 300m3 (for Phase 1)
- UVT: 70%
- UV dose, EOLL* > 50 mWs/cm2
