(1) Project site:
Hebei Anxin Economic Development Zone (Santai Park).
Jiacheng Sewage Treatment Co., Ltd. in Anxin County.
20,000 m3/d domestic sewage treatment.
(4) Date of operation:
(5) Investment, construction and operation:
It was invested, built and operated by Jiacheng Environmental Protection Engineering Co., Ltd. in the form of BOT.
2. Major environmental problems to be addressed
Centralized treatment of domestic sewage from Anxin Economic Development Zone and improvement of surface water quality in Anxin Economic Development Zone.
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 (GB18918-2002), for the effluent, CODcr≤50mg/L, BOD5≤10mg/L, SS≤10mg/L, TN≤15mg/L, TP≤0.5mg/L, NH3-N≤5 (8) mg/L, pH6-9.
4. Technological process
Influent → bar screen → grit chamber → primary sedimentation tank → biological aerated filter → sand filter → ultraviolet disinfection → effluent. The sludge is transported to the outside for disposal after press filtration and dewatering.
5. Environmental pollution control effects
For the influent, CODcr≤400mg/L, BOD5≤200mg/L, SS≤150mg/L, TN≤40mg/L, TP≤3mg/L, NH3-N≤25mg/L, pH6-9；For the effluent, CODcr≤50mg/L, BOD5≤10mg/L, SS≤10mg/L, TN≤15mg/L, TP≤0.5mg/L, NH3-N≤5 (8) mg/L, pH6-9. The effluent water was used as the water supplement for scenic environment and greening use.
6. Investment and operation cost
The total investment of the project was RMB 47.28 million and the operation cost was RMB 0.39/ t·water.
Highlights: With functions of nitrogen removal, carbon removal and suspended solids interception, the process features less sludge production, strong impact resistance, small floor area and low capital investment, and therefore it is more suitable for advanced treatment of sewage (wastewater).