The main contents of the design : Determination of process flow, design and calculation of the structures of sewage treatment, sludge treatment structures, the calculation of wastewater treatment plant of plane and elevation layout, accessory building and equipment selection. The main structures in a grid, pumping station, aerated grit tank, SBR reactor, disinfection tank, sludge thickening tank, sludge dewatering workshop. Design completed a total design specification, sewage treatment plant, general layout of a biological cell plane,profile of a sewage treatment plant, sewage and sludge flow elevation map,and optionally four other structures of the plane, profile, a total of 8 pictures of A2 converted into. The size of the sewage treatment plant for 50000m ³ /d, a relatively small amount of effluent treatment, required to achieve "urban sewage treatment plant pollutant discharge standard" (GB 18918 - 2002) in the two standards, SBR method that selected can removal nitrogen and phosphorus effectively[14].
Design material: a town sewage emissions for every 50000m ³, water quality according to the following considerations: CODcr ≤ 330mg/L, BOD5 ≤ 185mg/L, SS ≤ 320mg/L, N ≤ 40 NH3 - mg/L, TN ≤ 50 mg/L, TP ≤ 6 mg/L (the above data can be referred to relevant data to determine).
To achieve "urban sewage treatment plant pollutant discharge standard of water requirements" (GB 18918-2002) in the two standards: COD ≤ 100mg ≤ L-, BOD 30mg L-, SS ≤ 30mg ≤ L-, NH3-N 25mg L-, TN ≤ 20mg ≤ L-, TP 2.0mg L-.
Based on the design:
1) design task book
2) engineering data
3) corresponding design standard
《Urban sewage treatment plant pollutant discharge standard"》(GB 18918-2002)
《Urban sewage treatment plant subsidiary buildings and equipment design standards"》(GJ31 - 89)
4) manual
《Sewage treatment plant process design manual》 (The Second Edition)
After treatment, water quality prediction of COD ≤ 100mg ≤ L-, BOD 30mg L-, SS ≤ 30mg ≤ L-, NH3-N 25mg L-, TN ≤ 20mg ≤ L-, TP 2.0mg L-. To achieve 《urban sewage treatment plant pollutant discharge standard》 (GB18918-2002) in the two standards.
Key words: sequencing batch reactor activated sludge process; activated sludge; nitrogen and phosphorus removal; sewage treatment