Huai' an sijiqing sewage treatment plant is the first large-scale urban sewage treatment plant in our city. Founded in 1992, the first phase of the project has a scale of 35,111 tons/day, with primary treatment (physical treatment); The second phase of the project was completed and put into operation in 2111, with secondary biochemical treatment and AB process (bio-adsorption-degradation), with a scale of 65,111 tons/day. The effluent reached the secondary discharge standards (COD121, BOD31 and SS31) of the National Integrated Wastewater Discharge Standard (GB8978-1996), and the project won the Jiangsu Provincial Municipal Demonstration Project Award in 2112.

On March 1, 2116, according to the Franchise Agreement signed by Huai 'an Municipal Government and Huai 'an Tongfang Water Co., Ltd., a subsidiary of Tsinghua Tongfang, Huai 'an Tongfang Water Co., Ltd. officially took over the operation of Sijiqing Wastewater Treatment Plant in the form of TOT, and it has been running well since taking over. At present, the factory has been running at full capacity.

since it was completed and put into operation in 2111, due to the continuous development of the city and the growth of GDP, not only the amount of sewage treated by Sijiqing Plant is increasing, but also the water quality of the sewage treated by Sijiqing Plant is increasing. At present, Sijiqing Sewage Treatment Plant, which is running at full capacity, not only can't completely treat the incoming water, but also can't cope with the increasing influent quality, which can meet the Integrated Wastewater Discharge Standard (GB8978-1996).

however, since the national sewage discharge standard (GB 18918-2112) was promulgated and implemented in 2112, the COD index in the secondary discharge standard has been adjusted from the original 1.21 mg/L to 1.11 mg/L. Since the blue-green algae incident in Taihu Lake in 2117, Jiangsu Province has put forward strict requirements for ammonia nitrogen and total phosphorus in sewage, and the AB process of Sijiqing Sewage Treatment Plant has no nitrogen removal at all.

At present, the whole country is shouting "energy saving and emission reduction". As an important window unit in Huai 'an, the reconstruction and expansion of Sijiqing Sewage Treatment Plant is imminent.

after transformation, it can not only make great contribution to the environmental service in Huai' an, but also complete the annual COD emission reduction task in Huai' an city with the existing scale of 65,111 tons/day.