Oxygen Requirement calculation: Flow: Theoritical kg O2 required/kg of BOD: Inlet BOD: Hence BOD removed: Total O2 required: Oxygen required under Standard condition(SOR):
Hence Calculation of Air required at field condition SWD of Aeration Tank: HLL of Aeration Tank at avg flow: Height of diffuser: Effective Aeration Depth: SOTE: Fraction of O2 in Air: Specific gravity of Air: Hence Air required(SOR/((SOTE X Fraction Air)X( Specific gravity of Hours of of operation: Air): Air required: No of Working Air blower: Capacity of Air Blower: Capacity of Air Blower provided: No of Blower Provided: Hence no of operating Blower: No of standby provided:
Free Air Delivery No of diffusers required No of diffusers provided Calculation of SRT based on excess sludge : Excees sludge generated/kg of BOD: Kg of Total Sludge/day with total TSS load: Hence excess sludge: Sludge solid consistency at bottom of clarifier: Volume of Excess sludge(Qw): Hence sludge concentration(XR): Volume Aeration tank: MLSS concentration(X):
V
VIII
Secondary Clarifier Tank (ETP-TK-214) Flow Overflow Rate Area Diameter required Diameter provided SWD Free Board Total sludge=BOD Load + TSS Load Solid Loading rate Retention Time Weir Loading Feedwell Size
10 7.5 8
0.3 96.25 28.88 1 2.89 10000 109.38 4000
175 14 12.5 3.99 4 2.5 0.5 96.25 7.7 4.29 14 0.7
Sludge Recirculation Pump (ETP-PA-207A/S) Flow Capacity (based on 100% recirculation required during startup)
Head
175 7.3
10
m3/day mg/lt mg/lt (Accoring to sewage manual it may vary from 3000‐5000) mg/lt (Accoring to sewage manual it may vary from0.1‐0.18.) m3 m m2 m m m hrs(As per Sewage manual HRT 12‐24 hr, Hence OK)
175 m3/day 1.5 250 mg/l 250 mg/l 65.63 kg/day(AOR) AOR/[((β C'sw‐C)/Csw) X 1.024^(T‐20) X α XF) Field Temperature 25 Solubility of Oxygen at 20degC Solubility of O2 at field temperature: Design DO concentration Oxygen transfer correction factor Salinity surface tension correction factor Diffuser fouling factor 130.65 kg/day
m m m m % % Nm3/day hr Nm3/hr/basin Nm3/hr Nm3/hr No. No. No.
9.17 9.08 3 0.8 0.95 0.9 1 131.9491645017
mg/l mg/l mg/l mg/l
N m3/hr nos nos
As per CPEEHO Sewage manual the range is 0.25‐0.35 Kg/day Kg/day m3/day mg/l m3 mg/l
m3/day m3/m2.day(Ranges 8‐16, Refer page 687, Table 8‐7, Matcalf Eddy) m2 m m m m kg/day kg/m2.day <120 Hence OK(Refer page 687, Table 8‐7, Matcalf Eddy) hrs m3/m.day<185 Hence OK(Refer Sewage Manual) m(15% to 20% of clarifier dia)
m3/day m3/hr
m
Metcalf Eddy page 429
Refer Table D‐1 Appendix D Metcalf Refer Table D‐1 Appendix D Eddy Metcalf 0.4 topage:1745 0.8 for diffused system and 0.6 to 1.2 for mechanical system Eddy page:1745 0.7 to 0.98 0.65 to 0.9
