Pricing
239/33310–15FE Reference Handbook 10.4 · Environmental · Filtration
1. CMFR Steady Mass Balance2. BOD First-Order Kinetics3. Overflow Rate & Weirs4. Hydraulic Detention Time5. Chick’s Law6. Hardness as CaCO₃7. Recycle Ratio8. Theoretical Oxygen Demand (ThOD)9. PFR First-Order Design Time10. Solids Loading Rate11. Population Growth12. Weir Loading Rate13. Solids Retention Time (Sludge Age)14. CT Disinfection Product15. Food-to-Microorganism Ratio16. Alkalinity as CaCO317. Streeter–Phelps Oxygen Sag18. Sludge Volume Index (SVI)19. Filter Hydraulic Loading20. Chlorine Demand and Residual21. Grit Chamber Overflow and Stokes Settling22. Flow Equalization Volume

Handbook formula

Filter Hydraulic Loading

Approach velocity on the filter box. Also check solids loading. Head loss grows with time until backwash. Declining-rate and constant-rate are two modes.

(m/h)
Hydraulic loading
Plan area of media

Step-by-step solved example

Q=0.12 m³/s, two filters 4 m × 5 m each. v?

QAOR = Q/A
Filter box: v = Q/A on the media plan area.

  1. 1. A

    2×20=40 m².

  2. 2. v

    0.12/40=0.003 m/s=10.8 m/h (rapid).

Answer: v = 10.8 m/h

10 practice questions

0/10 correct

1.Slow sand loading is much

2.Backwash expands the bed so that

3.Q=4 MGD, A=800 ft²: v nearest

4.Anthracite over sand is a

5.Turbidity breakthrough triggers

6.L/d of media (depth/grain) affects

7.With one filter down, v on the rest

8.0.003 m/s in m/h is

9.GAC adsorbers are often rated by

10.Negative pressure in a dirty gravity filter risks