Chongqing Tangjiatuo WWTP protects water resources of the upper-middle reaches of Yangtze River
Chongqing, located in the area of Three Gorges Reservoir and at the intersection of multiple water bodies, has a large population and boasts prosperous economy, while at the same time, shoulders an arduous responsibility for environmental protection. In 2007, SUEZ NWS took over the management of Chongqing Tangjiatuo Wastewater Treatment Plant by TOT model, starting to provide wastewater treatment services for over one million citizens in Jiangbei District, Yubei District and Liangjiang New Area, Chongqing.
Protecting water resources of the upper-middle reaches of Yangtze River
Located in the middle-upper reaches of Yangtze River and the Three Gorges Reservoir area, Chongqing is China's largest and most populated municipality. It is undoubtedly a huge challenge to provide quality wastewater treatment services for the city populated by over 10 million residents, while at the same time guaranteeing the economic development. The Chongqing municipality therefore implements the most stringent wastewater standards.
CODcr discharge standard
total nitrogen discharge standard
WWTP with most complete processes and advanced technologies
Chongqing Tangjiatuo WWTP, invested and operated by SUEZ NWS, adopts the mature and advanced A-A2O treatment process, sludge digestion and dewatering and INNODRY®2E sludge drying process; it is equipped with the resources recovery and recycling facilities, such as: treated wastewater power generation and wastewater reuse systems. The plant is currently one of the WWTPs with the most complete processes and advanced technologies in Western China and even the whole country.
Harmless treatment and resource recycling of sludge
The plant uses SUEZ' patented INNODRY®2E sludge drying process, which functions to dry the sludge after digestion and dewatering, and bring the water ratio from 75% down to 10%, which has totally changed the original practice of sending the dewatered sludge to the sanitary landfill. Currently, the dried sludge is delivered to a local cement plant, to be mixed with coal as fuel for combustion during its production. In this way, we achieved harmless treatment and resource recycling of sludge.
Exploit resources from wastewater
The plant invested 11 million RMB to build a treated wastewater power plant with an installed capacity of 800Kw, which can directly substitute 10% of the plant's electricity use in production. In addition, the plant is equipped with a water reuse system, which is applied to greening, road cleaning, equipment cooling and other applications in the plant, saving about 96% of the water use across the whole plant.
Tangjiatuo WWTP provides daily municipal wastewater treatment services for 1 million citizens, covering an area of 100 km2 in Jiangbei District, Yubei District, and Liangjiang New Area, Chongqing, with daily wastewater treatment capacity of 400,000 tons, and daily sludge drying capacity of 240 tons. It effectively protects the water resources of the upper-middle reaches of Yangtze River and guards the quality of living in Chongqing.
The plant has creatively adopted resource recycling solutions, such as biogas production from anaerobic digestion of wastewater sludge, treated wastewater power generation, and water reuse facilities, so as to greatly reduce the consumption of natural gas, electricity and water resources. As a result, it saves the natural gas of 4 million Nm3, electricity of 550 kW.h, and water of 3.7 million m3 every year.