(1) Project site:
It is located near Hancheng Toll Station, Zhuhong Road North, Xi’an
Xi’an Sewage Treatment Co., Ltd.
250,000 m3/d sewage treatment.
(4) Date of operation:
(5) Investment, construction and operation:
It was invested, built and operated by the Owner and Thunip Corporation Ltd. was the EPC contractor.
2. Major environmental problems to be addressed
Upgrade and renovation of the sewage treatment plant.
3. Environmental standards and/or main index limits to be followed
According to Grade 1-A standards of the Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002), for the effluent, COD≤50mg/L, SS≤10mg/L, NH3-N≤5mg/L, TN≤15mg/L and TP≤0.5mg/L.
4. Technological process
Coarse bar screen→ aerated grit chamber → fine bar screen→ primary sedimentation tank → superfine bar screen→ anaerobic suspended media zone→ anoxic suspended media zone → anoxic zone → aerobic zone → secondary sedimentation tank → cloth filter → disinfecting tank → effluent.
5. Environmental pollution control effects
For the influent, CODcr 258~1036mg/L, SS 224~789mg/L, NH3-N 16~47mg/L, TN17~68mg/L, TP4.84~17.31mg/L；for the effluent, CODcr 15.2~29.8mg/L, SS 4~7mg/L, NH3-N 0.11~2.75mg/L, TN4.81~9.5mg/L, TP0.14~0.41mg/L.
6. Investment and operation cost
The investment was about RMB 200/t·water, and the operation cost was about RMB 0.4/t·water.
Highlights: The anaerobic ammoxidation is realized in the main process of municipal sewage treatment under ambient temperature and low concentration by using the enhanced denitrification and dephosphorization technology based on the anaerobic-anoxic fluidized bio-carrier. Compared with the traditional A2O process, the TN removal efficiency can be increased by 20% and the total phosphorus removal efficiency by more than 25%, saving land occupation and investment. It is of great significance to the construction, upgrade and renovation and reduction of operation cost of the sewage plant.