Copyright © 2025 K.G.Matzen. Powered by iglobalwin.com
An aerated grit chamber is a pretreatment facility that enhances sand particle separation through forced aeration.
Application
• Municipal Wastewater Treatment Plants
• Core unit in the pretreatment stage, especially suitable for combined sewer systems (with high sand content).
• Design criteria
• Food processing (containing animal hair, bone debris), papermaking (high fiber impurities), mining wastewater (high-density particles).
• Stormwater Treatment Facilities
An aerated grit chamber is a pretreatment facility that enhances sand particle separation through forced aeration.
Application
• Municipal Wastewater Treatment Plants
• Core unit in the pretreatment stage, especially suitable for combined sewer systems (with high sand content).
• Design criteria
• Food processing (containing animal hair, bone debris), papermaking (high fiber impurities), mining wastewater (high-density particles).
• Stormwater Treatment Facilities
Description
Tank Configuration
• Geometric Features: Rectangular or trapezoidal tank with a length-width ratio ≥4:1, effective water depth of 2–5 m, and a grit hopper at the bottom (slope ≥45°).
Aeration System
• Perforated aeration pipes or micro-porous diffusers arranged along the tank length, positioned 0.6–1.0 m above the tank bottom.
• Air-water ratio controlled at 0.1–0.3 m³ air/m³ sewage.
Inlet and Outlet Structures
• Inlet end equipped with a flow straightening baffle.
• Outlet end fitted with a scum baffle and overflow weir.
Flow and Aeration Dynamics
• Aeration creates a spiral flow pattern (horizontal vortex + vertical eddy current) with a flow velocity of 0.25–0.4 m/s.
• Hydraulic retention time (HRT): 2–5 minutes.
• Surface load: ≤200 m³/(m²• h).
Advantages
Efficient Separation of Inorganic Sand Particles
|
Comparison Items |
Aerated Grit Chamber |
Common Grit Chambers (Horizontal/Vertical Flow) |
|
Sand Particle Removal Rate |
>95% (particle size ≥ 0.2mm) |
70%~85% |
|
Organic Matter Entrainment Rate |
20% (prone to entraining organic matter) |
|
|
Principle: The eddy currents generated by aeration cause sand particles to rub against each other, stripping organic adhesives from their surfaces and improving sand particle purity. |
||
Simultaneous Removal of Scum and Grease
• Aeration agitation promotes the floating of grease and light scum to the water surface, which is then removed by a scum scraper.
• Capable of removing 60%–80% of floating oil (particularly suitable for food processing and slaughterhouse wastewater).
Strong Resistance to Flow Fluctuations
• Adjustable aeration intensity (e.g., variable-frequency blowers) adapts to impact loads with flow variations of ±50%.
Reduced Equipment Wear and Subsequent Blockages
• Efficient removal of sand particles protects downstream pumps, pipelines, and sludge dewatering equipment, reducing wear rate by >40%.
• Prevents sand accumulation in biological tanks (reducing cleaning frequency by over 50%).
Improved Water Quality Homogenization
• The aeration process promotes sewage mixing, mitigating fluctuations in water quality (e.g., pH, temperature), and enhancing the stability of subsequent biological treatment.
Description
Tank Configuration
• Geometric Features: Rectangular or trapezoidal tank with a length-width ratio ≥4:1, effective water depth of 2–5 m, and a grit hopper at the bottom (slope ≥45°).
Aeration System
• Perforated aeration pipes or micro-porous diffusers arranged along the tank length, positioned 0.6–1.0 m above the tank bottom.
• Air-water ratio controlled at 0.1–0.3 m³ air/m³ sewage.
Inlet and Outlet Structures
• Inlet end equipped with a flow straightening baffle.
• Outlet end fitted with a scum baffle and overflow weir.
Flow and Aeration Dynamics
• Aeration creates a spiral flow pattern (horizontal vortex + vertical eddy current) with a flow velocity of 0.25–0.4 m/s.
• Hydraulic retention time (HRT): 2–5 minutes.
• Surface load: ≤200 m³/(m²• h).
Advantages
Efficient Separation of Inorganic Sand Particles
|
Comparison Items |
Aerated Grit Chamber |
Common Grit Chambers (Horizontal/Vertical Flow) |
|
Sand Particle Removal Rate |
>95% (particle size ≥ 0.2mm) |
70%~85% |
|
Organic Matter Entrainment Rate |
20% (prone to entraining organic matter) |
|
|
Principle: The eddy currents generated by aeration cause sand particles to rub against each other, stripping organic adhesives from their surfaces and improving sand particle purity. |
||
Simultaneous Removal of Scum and Grease
• Aeration agitation promotes the floating of grease and light scum to the water surface, which is then removed by a scum scraper.
• Capable of removing 60%–80% of floating oil (particularly suitable for food processing and slaughterhouse wastewater).
Strong Resistance to Flow Fluctuations
• Adjustable aeration intensity (e.g., variable-frequency blowers) adapts to impact loads with flow variations of ±50%.
Reduced Equipment Wear and Subsequent Blockages
• Efficient removal of sand particles protects downstream pumps, pipelines, and sludge dewatering equipment, reducing wear rate by >40%.
• Prevents sand accumulation in biological tanks (reducing cleaning frequency by over 50%).
Improved Water Quality Homogenization
• The aeration process promotes sewage mixing, mitigating fluctuations in water quality (e.g., pH, temperature), and enhancing the stability of subsequent biological treatment.