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Trickling Filter Characteristics |
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| The following data is based on industry practices and Brentwood experience. It is compiled from several sources and is incorporated into the Brentwood Industries Trickling Filter Evaluation Program (1) (2). | |
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| TRICKLING FILTER TYPE | ROCK MEDIA | PVC MEDIA | ||||
| Loading Characterization | Low Loading Rate |
Intermediate Loading Rate |
High Loading Rate |
Nitrification | High Rate BOD Removal Only | Roughing Rate |
| HYDRAULIC LOADING (averages) | ||||||
| gal/ft.2-day | 25 to 90 | 90 to 230 | 230 to 900 | 750 to 2880 | 350 to 2880 | 1500 to 4500 |
| gal/ft.2-min | 0.02 to 0.06 | 0.06 to 0.16 | 0.15 to 0.60 | 0.5 to 2.0 | 0.25 to 2.0 | 1.0 to 3.0 |
| m3/m2-day | 1.0 to 3.5 | 3 to 10 | 10 to 40 | 30 to 120 | 15 to 120 | 60 to 180 |
| m3/m2-hr | 0.05 to 0.15 | 0.15 to 0.40 | 0.40 to 1.5 | 1.5 to 5.0 | 0.5 to 5.0 | 2.5 to 7.5 |
| mgd/acre | 1.0 to 4.0 | 4.0 to 10.0 | 10 to 40 | 30 to 120 | 15 to 120 | 60 to 180 |
| ORGANIC LOADING FACTORS | ||||||
| lbs/1000 ft3-day | 5 to 15 | 15 to 30 | 30 to 150 | 10 to 35 | 30 to 300 | 100 to 500 |
| kg/m3-day | 0.08 to 0.24 | 0.25 to 0.50 | 0.5 to 2.5 | 0.15 to 0.50 | 0.5 to 5.0 | 1.5 to 7.5 |
| lbs/acre-ft-day | 200 to 600 | 650 to 1300 | 1300 to 6500 | 400 to 1400 | 1300 to 13000 | 4000 to 20000 |
| RECIRCULATION & DOSAGES | ||||||
| Recycle Ratios | 0.1 to 0.5 | 0.1 to 1.0 | 1.0 to 2.0 | 1.0 to 2.0 | 1.0 to 12.0 | 0.0 to 1.0 |
| Dosing Intervals, 2 Arms (minutes) |
0.5 to 0.25 | 0.5 to 0.25 | 0.5 to 0.25 | 0.5 to 0.25 | 0.5 to 0.25 | 0.5 to 0.25 |
| Dosing Intervals, 4 Arms (minutes) |
0.3 to 0.1 | 0.3 to 0.1 | 0.3 to 0.1 | 0.3 to 0.1 | 0.3 to 0.1 | 0.3 to 0.1 |
| Deluge Rates, 2 Arms (gal/pass or dose-ft2) | 0.01 to 0.02 | 0.03 to 0.08 | 0.15 to 0.45 | 0.5 to 1.5 | 0.25 to 6.5 | 0.5 to 1.5 |
| Deluge Rates, 4 Arms (gal/pass or dose-ft2) | 0.005 to 0.01 | 0.02 to 0.04 | 0.08 to 0.24 | 0.25 to 0.75 | 0.10 to 3.0 | 0.25 to 0.75 |
| Average Water Velocity in Filter Bed (ft/min) |
0.003 to 0.008 | 0.01 to 0.02 | 0.02 to 0.08 | 0.05 to 0.25 | 0.03 to 0.25 | 0.15 to 0.40 |
| Distributor Sweep Velocity (ft/sec) |
1 to 12 | 1 to 12 | 1 to 12 | 1 to 12 | 1 to 12 | 1 to 12 |
| SK RATES | ||||||
| Revs Per Minute, Normal Operation |
1.0 to 2.0 | 1.0 to 2.0 | 1.0 to 2.0 | 1.0 to 2.0 | 1.0 to 2.0 | 1.0 to 2.0 |
| If 2 Arms (inches) | 0.015 to 0.040 | 0.05 to 0.15 | 0.25 to 0.75 | 0.8 to 2.4 | 0.4 to 10.0 | 0.8 to 2.4 |
| If 4 Arms (inches) | 0.01 to 0.02 | 0.03 to 0.06 | 0.1 to 0.4 | 0.4 to 1.2 | 0.20 to 5.2 | 0.4 to 1.2 |
| If 2 Arms (mm) | 0.4 to 1.0 | 1.40 to 3.4 | 6.5 to 20 | 20 to 60 | 10 to 250 | 20 to 60 |
| If 4 Arms (mm) | 0.2 to 0.5 | 0.70 to 1.7 | 3.0 to 10.0 | 10 to 30 | 5 to 125 | 10 to 30 |
| Revs per Minute, Flushing Mode |
0.05 to 0.10 | 0.05 to 0.10 | 0.05 to 0.10 | 0.05 to 0.10 | 0.05 to 0.10 | 0.05 to 0.10 |
| If 2 Arms (inches) | 0.3 to 0.4 | 1.1 to 1.3 | 5.0 to 7.5 | 15 to 25 | 10 to 100 | 15 to 25 |
| If 4 Arms (inches) | 0.15 to 0.20 | 0.5 to 0.6 | 2.5 to 4.0 | 8 to 12 | 4 to 50 | 8 to 12 |
| FILTER FLIES | ||||||
| Number of Flies | Many | Varies | Few | Few to None | Few to None | Few to None |
| SLOUGHING | ||||||
| Frequency | Intermittent | Varies | Continuous | Intermittent | Intermittent | Continuous |
| STANDARD DEPTH OF MEDIA | ||||||
| Depth in Feet | 3 to 8 | 6 to 8 | 6 to 10 | 6 to 30 | 6 to 30 | 6 to 30 |
| Depth in Meters | 1 to 2.5 | 2 to 2.5 | 2 to 3 | 2 to 10 | 2 to 10 | 2 to 10 |
| BOD5 REMOVAL RANGES | ||||||
| Percentage | 80 to 85 | 50 to 70 | 65 to 80 | 80 to 95 | 65 to 85 | 40 to 65 |
| NH3-N REMOVAL RANGES | ||||||
| Nitrification Condition | Well-Nitrified | Some Nitrification | Trace Nitrates | Full Nitrification | Limited Nitrification | No Nitrification |
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References: (1) WEF MOP 8 Design of Municipal Wastewater Treatment Plants: Fourth Edition (1998) (2) Water Pollution Control Federation MOP 8 Wastewater Treatment Plant Design (1977) |
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