MBR technology helps 2008 games go 'green'
As part of its preparation for the 2008 games, the city of Beijing, China wanted to adopt eco-friendly transportation, power generation and water management technologies...
As part of its preparation for the 2008 games, the city of Beijing, China wanted to adopt eco-friendly transportation, power generation and water management technologies. One of their goals was to process 90% of the city's wastewater and re-use 50% of the treated effluent.
The Chinese government decided to expand the Beixiaohe Wastewater Treatment Plant's capacity from 40,000 to 100,000 m³/day. In June 2006, the Beijing Drainage Group awarded Siemens China a US$18.5 million contract to provide a 60,000 m³/day water reuse system for the Beixiaohe plant. The system includes a Membrane Bioreactor (MBR) system, which treats wastewater for reuse in the Olympic Village central area, fountains and lakes. The Drainage Group chose the Siemens MBR system because it is 60% smaller than conventional treatment technologies, and fit exactly in the plant's existing space. The MBR system contains biological and membrane treatment steps. With 4,864 membranes, the system is one of the largest of its kind in the world. Besides the MBR system, Siemens provided process design, mechanical equipment, electrical and automation systems, instrumentation, installation supervision and operation and maintenance training.
The project had to be completed well before the start of the games on August 8, 2008 -- an aggressive schedule for a system this large and complex. Equipment delivery spanned four continents and six time zones. The coordination logistics for engineering, testing and on-time delivery were complex. To meet the deadline, civil, mechanical, electrical, and installation contractors worked in parallel. At the height of the installation, more than 600 workers were onsite. A further challenge was meeting the membrane installation schedule. The membranes had to be installed when temperatures were above +5 degrees C, as exposure to lower temperatures could permanently damage the membrane fibers. The project team needed enough time to safely assemble the membranes in their respective racks and submerge them in clean water before the cold weather set in. This operation required continuous supervision to avoid damaging the costly membranes.
Three months before the beginning of the 2008 games, Siemens started up the wastewater reuse system. Siemens signed the final acceptance certificate on July 4th -- just one month after commissioning -- and all performance tests on the system were completed by July 24th. This is quite an accomplishment, as if often takes six months to obtain acceptance on a project of this scope.
The MBR treats 60,000 m³/day of water for reuse, and 10,000 m³/day of that water is further treated with a reverse osmosis system for decorative fountains and a "theme" lake.
Says Mr. Shi Lei, the Drainage Group's project manager, "Siemens showed great flexibility in supporting this important project to a successful completion. They constantly adapted to new situations onsite, and adjusted expert supervision accordingly."