SINO-Nutrients – Treatment of wastewater with high industrial share with extreme demands on nutrient elimination in Suzhou, P.R. China

Joint Project of the BMBF initiative IC Major Water

China has experienced rapid industrial and economic development for years. This applies particularly to the Shanghai region. The high water demand and insufficient treatment of waste water from municipalities, industry and agriculture resulted in a considerable deterioration of the quality of available water resources. This applies especially to the Lake Tai, the most important regional water resource. For this reason, the Lake Tai is the Chinese mega water resource that has been providing the highest water protection investments since 2006 within the Major Water Program. In addition, the Lake Tai is the target region of the SIGN (Sino-German Water Supply Network) project funded by the BMBF and focussed on improving the quality of water supply.

The relevance of this water resource to the water supply of the metropolitan region from Wuxi via Suzhou to Shanghai is shown mainly by the significantly increased requirements for the discharge of the wastewater treated by sewage treatment plants in the Taihu catchment area, as communicated within the framework of the 13th Five-Year Plan. For example, they were tightened to a maximum of 10 mg/l for the parameter total nitrogen.

The research project Sino-N, funded under a SINOWATER increase by the BMBF, therefore promotes the further elimination of the nutrients entered into the waters in the SIGN region. Sino-N thus represents a sensible addition to the previous observations made in SIGN.

The aim is to optimize the removal of nutrients from waste water by means of a combined approach consisting of improved wastewater management by means of an indirect discharge cadaster and the use of innovative German process technology for further elimination of phosphorus and, above all, nitrogen.

A downstream anoxic filter for the further reduction of the nitrate-nitrogen (NO3-N) in the wastewater treatment plant is to be investigated on the one hand. On the other hand, an SBR / MBBR reactor with upstream magnesium-ammonium-phosphate precipitation is considered within the framework of the project as well as a deammonification reactor for the treatment of the process waters.

On the basis of the scientifically elaborated results of the experiments carried out, there are subsequently made statements regarding the transferability of the methods used to their large-scale usage as well as corresponding optimization potentials of the sewage treatment plant considered.