Fluoride Feed Dose (Available Fluoride Ion)
The pounds-per-day of a fluoridation chemical to hit a target fluoride level.
Example
You enter
- Target fluoride (mg/L) 0.7
- Raw background fluoride (mg/L) 0.1
- Flow (MGD) 2
- Available fluoride ion (0-1): FSA 0.792, NaF 0.452, Na2SiF6 0.607 0.792
- Purity / solution strength (0-1) 0.25
You get
- Chemical feed 50.55
- Pure fluoride ion fed 10.008
Details, formula, and sources
The pounds formula (net dose x flow MGD x 8.34), divided by the AVAILABLE FLUORIDE ION (AFI) fraction and the commercial strength, after first SUBTRACTING the raw background fluoride the water already carries. AFI is fixed per chemical: fluorosilicic acid (H2SiF6) 0.792, sodium fluoride (NaF) 0.452, sodium fluorosilicate (Na2SiF6) 0.607. Feeding a net 0.6 mg/L (0.7 target minus 0.1 raw) into 2 MGD with 25% fluorosilicic acid = 0.6 x 2 x 8.34 / (0.792 x 0.25) = 50.55 lb/day of acid, carrying 10.0 lb/day of fluoride ion. US PHS target 0.7 mg/L. A feed-setpoint aid; the daily lab checks, the SDWA maximum, the exact product assay, and the state fluoridation program govern.
net_dose = target_dose_mg_l - raw_fluoride_mg_l; pure_fluoride_lb_day = net_dose x flow_mgd x 8.34; feed_lb_day = pure_fluoride_lb_day / (afi_fraction x purity_fraction). AFI: fluorosilicic acid 0.792, sodium fluoride 0.452, sodium fluorosilicate 0.607.
Water-fluoridation feed calculation (CDC Water Fluoridation / AWWA practice), the available-fluoride-ion pounds formula, by name; the state fluoridation program, the SDWA maximum, and the product assay govern.
The pounds formula and the available-fluoride-ion fractions are public water-fluoridation practice; the target dose, raw fluoride, flow, and product strength are the plant's values.
Estimate. AHJ and licensed professional govern.
Field names used by the API: target_dose_mg_l, raw_fluoride_mg_l, flow_mgd, afi_fraction, purity_fraction, feed_lb_day, pure_fluoride_lb_day
- Available-fluoride-ion pounds formula feed = (target - raw) x flow MGD x 8.34 / (AFI x purity); dose only the net above the raw backgroundCDC Water Fluoridation / AWWA practice
- AFI by chemical fluorosilicic acid 0.792, sodium fluoride 0.452, sodium fluorosilicate 0.607; US PHS target 0.7 mg/L; the SDWA MCL and the state program governCDC / AWWA water fluoridation