1 IV. Wastewater Treatment technologies Topic IV. 9. Wastewater Treatment Facilities with Suspended...
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Transcript of 1 IV. Wastewater Treatment technologies Topic IV. 9. Wastewater Treatment Facilities with Suspended...
1
IV. Wastewater Treatment technologies
Topic IV. 9. Wastewater Treatment Facilities with Suspended Biomass - Aerated Tanks: Kinds, Structures, Basic Technological Parameters
Kinds of Aerated Tanks
I. According to the hydrodynamic conditions Completely mixed reactors Plug flow reactors Diffusion reactors Cell reactors
II. According to the aeration system With pneumatic aeration With surface (mechanical) aeration With combine aeration With pure oxygen supply (oxytanks)
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Kinds of Aerated Tanks
III. According to the activated sludge regeneration Conventional (without activated sludge regeneration) Contact stabilisation (with activated sludge regeneration)
IV. According to activated sludge separation With separate secondary settling tanks With combined aerated tanks/settling compartments With membrane activated sludge separation
V. According to the stages One stage Two stages
VI. According to the structures and distribution Conventional (corridor) Carousel Stepwise wastewater (or air) distribution
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Kinds of Aerated Tanks
Schemesa - without regenerator б - with regenerator
1 - wastewater influent; 2 - aerated tank; 3 - secondary clarifier; 4 - regenerator; 5 - mixed
liquor; 6 - wastewater effluent; 7 - recirculating activated sludge; 8 - waste activated sludge
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Aerated Tanks Structures
Conventional Aerated Tank with Pneumatic Aeration
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Aerated Tanks Structures
Fine Bubbles Pneumatic Aeration System with Distributing Channels and Filtering Plates
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Aerated Tanks Structures
Fine Bubbles Dome-wise
Aerator
Fine Bubbles Disk- wise
Aerator
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Aerated Tanks Structures
Surface (mechanical) Aerator
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Basic Technological ParametersX - activated sludge concentration (SS) in
the aerated tank, g/m3
Rw - aerated tank volume hydraulic load, m3/m2.d
RL - aerated tank organic load, gBOD5/m3.d
RFM - food to micro-organisms ratio (F/M ratio), gBOD5/gSS.d
U - substrate utilisation rate, gBOD5/gVSS.h
x - activated sludge age, d
I - activated sludge index, cm3
r - activated sludge recirculation ratio
EO - specific oxygen demand, gO2/Rw
t - hydraulic retention time, h
Q - wastewater flowrate, m3/h
W - aerated tank volume, m3
Qr - recirculating activated sludge flowrate, m3/h
Xr - recirculating activated sludge concentration, g/m3
QWAS - waste activated sludge flowrate, m3/h
QO2 - oxygen mass rate, g/h
WQRw /
WLQRL /. 0
XWLQRFM ./. 0
WASrx QXXW ./.
rrr XXXQQr /)(/
woO REQ .2