DESIGN OF WASTEWATER TREATMENT PLANT ClarifierSedimentation Tank Design
- Slides: 43
DESIGN OF WASTEWATER TREATMENT PLANT
Clarifier/Sedimentation Tank Design
Design criteria The following design criteria are generally assumed to design a Primary Settling Tank / Sedimentation A) GENERAL No. of Tanks 2 or more (usually) Types of tanks Circular or rectangular Removal of Sludge and Scum Mechanical (usually) Tank bottom slope 60 -150 mm/m Speed of sludge scraper 0. 02 – 0. 05 rpm
B) DIMENSIONS Rectangular Tank Circular Tank C) TECHNICAL Range Typical Length (m) 15 -100 30 Width (m) 3 -30 10 Depth 2. 5 -5 4 Diameter (m) 3 -60 30 Depth (m) 3 -5 4 Bottom slope, (mm/mm) 0. 02 – 0. 05 0. 03 Range Typical Detention Time, t (hr) 1. 0 – 4. 0 2. 0 Flow Through velocity (m/min) 0. 6 – 3. 6 0. 9 SLR (m 3/m 2/hr) at average flow 1. 2 – 2. 5 1. 6 Peak Hourly Flow 2. 0 – 5. 0 4. 2 WLR (m 3/m/d) 125 - 500 250
Primarily used in WWT to separate solids from liquids in effluent streams. Types light Clarifiers Criteria for sizing clarifier (settling tank) Tank depth at the side wall Detention time Overflow rate (surface loading rate) Scour velocity
Criteria For Sizing Clarifier (Settling Tank) -Overflow Rate (Surface Settling Rate)Definition: The average daily flow rate divided by the surface area of the tank. Clarifiers overflow rate @ surface settling rate (m 3/m 2 d) Average daily flowrate (m 3/day) Total surface area of the tank (m 2)
Criteria For Sizing Clarifier (Settling Tank) -Depth Of Tank- Depth of tank The water depth at the side wall measuring from the tank bottom to the top of the overflow weir. Exclude the additional depth resulting from slightly sloping bottom that is provided in both circular and rectangular clarifiers. Effluent weir Influent H Occupied with sludge Effluent weir loading (typical= 250 m 3/m. d) is equal to quantity of WW flowing divided by the total weir length, Lw Average daily flowrate (m 3/day) Total weir length (m)
Criteria For Sizing Clarifier (Settling Tank) -Detention Time- Detention time length of time a particle or a unit volume of WW remains in a reactor Detention time (day) 3 = Tank volume (m ) Average daily flowrate (m 3/day)
CRITERIA FOR SIZING CLARIFIER (SETTLING TANK) -SCOUR VELOCITY Scour Velocity horizontal velocity through the tank to avoid resuspension of settled particles Where: VH = horizontal velocity that will just produce scour (m/s) k = cohesion constant that depends on type of material being scoured (unitless) s=specific gravity of particles g=acceleration due to gravity (9. 81 m/s 2) d=diameter of particles f=Darcy-Weisbach friction factor (unitless)
Example:
Stabilization pond design
In series
Design Parameters
Facultative Pond
Design Criteria � Surface Organic Loading Rate � Depth � Detention Time � Geometry (L/B ratio)
Surface Organic Loading Rate � Related with algae activity and balance between oxygen production and consumption.
Depth
Depth
Depth � Based on volume, V and the required area, A , the depth (H) of pond = V/A. � H = 1. 5 to 2. 0 m
Detention time � In primary detention time, t usually vary from 15 to 45 days.
L/B Ratio
If K = 0. 35 d-1 θ=1. 085 If K = 0. 30 d-1 θ=1. 05
Example
Solution
ANAEROBIC POND DESIGN
Volumetric Loading Rate
Volumetric Loading Rate
Detention Time
Depth
L/B Ratio
AEROBIC POND DESIGN � Design Criteria � Detention time, t = 5 to 10 days � Depth, H = 2. 5 to 4. 0 m � Oxygen Requirement � Power Requirement
Oxygen Requirement
Power Requirement
Activated sludge design
- Clarifier design example
- Ashbridges bay water treatment plant
- Sacramento regional wastewater treatment plant
- Nampa wastewater treatment plant
- Wastewater treatment purpose
- Characteristics of aquaculture wastewater
- Wastewater treatment process primary secondary tertiary
- Municipal wastewater treatment
- Agricultural wastewater treatment technologies
- Anaerobic wastewater treatment
- Agricultural wastewater treatment technologies
- Secondary wastewater treatment
- Wastewater treatment for dairy industry
- Secondary wastewater treatment
- Conclusion of wastewater treatment ppt
- Anaerobic methane digester frq
- "novo wastewater treatment" -honeycomb
- Wastewater infrastructure design in texas
- Horizontal flow grit chamber design example
- Mohra water treatment plant
- Baker water treatment plant
- Water treatment plant
- Water treated from sewage treatment plant
- Dbo water plants
- Ashbridges bay treatment plant
- Wastewater distribution system
- Typical composition of untreated domestic wastewater
- Characteristics of wastewater
- Risk management for water and wastewater utilities
- Optimize wastewater lagoon
- Oregon water treatment certification
- Peak hourly flow wastewater
- Lagos state wastewater management office
- Bioline netafim
- Fertilizer with nitrogen
- Sherwin williams polyurea
- Objective of water pollution
- Scwwa
- Wastewater 101
- Pueblo wastewater
- Design of percolation tank
- Culture tank design
- Vacuum tank design
- Tank design game