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 to strengthen ecological protection in the upper reaches of the Yangtze River.
excellent water quality in Chongqing section of the Yangtze River mainstream
water qualified in water bodies of important rivers, lakes and reservoirs

Our solution

WWTP with the most complete processes and advanced technologies

Chongqing Tangjiatuo WWTP, invested and operated by SUEZ, adopts the mature and advanced A-A2O treatment process, sludge digestion and dewatering and EvaporisTM 2E two-stage 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 most complete WWTPs in terms of processes and advanced technologies in the country.

Harmless treatment and resource recycling of sludge

The plant uses SUEZ' EvaporisTM 2E two-stage sludge drying process, which functions to dry the sludge after digestion and dewatering, and brings the water ratio from 75% down to 10%. This 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 has built a treated wastewater power plant with an installed capacity of 800Kw, which can directly substitute 10% of the plant's electricity usage for 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 94% of the water use across the whole plant.

The results

  • 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 a 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, to greatly reduce the consumption of natural gas, electricity and water resources.
  • In the first selection of “Towards the next centenary goal” benchmark of WWTP, Tangjiatuo WWTP won two benchmarks for its operation management and precise control in critical processing.

million m3/year
water saved by reclaimed wastewater recycling
power saved by hydro-power generation
people benefit from our wastewater treatment services