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Wastewater Formula Examples

Formula Math Toolbox Example

 Mass Load (kg/day) = Flow {MGD} x Concentration {mg/L} x 3.785 

V6 * V46 * 8.34

Where: V6 is flow in MGD, 
V46 is concentration in mg/L

V452 / V450 * 1000

Where: V452 is 30 min settleometer, V450 is MLSS

V102/V460

Where: V102 is BOD primary effluent lbs, V460 is MLSS lbs

V460 / V101

Where: V460 is MLSS lbs, V101 is TSS lbs in primary effluent

V460 / ( (V350 * V351 * 8.34) + (V131 * V101 * 8.34))

Where: V460=MLSS lbs, V350= WAS Flow (MGD), V351 = RAS/WAS SS {mg/L} V131= Eff TSS {mg/L}, V101=Effluent Flow {MGD}

Note: Typically SRT does not include the Solids in the Secondary Clarifiers 

Method #1

(V460+V413) / (V399+V132)

Where: V460=MLSS lbs, V413=secondary clarifier lbs, V399=WAS lbs, V132=effluent TSS lbs

Method #2

(V461*2.5*8.34) / (( V350*V352*8.34) + (V132*V101*8.34)

Where: V461 = MLVSS,  2.5 Vol of Aeration in MG, V350 = WAS Flow (MGD), V352 RAS/WAS VSS (mg/L)V132 = Eff VSS (mg/L),  V101 = Eff Flow (MGD)

V399/(V102-V131)

Where: V399=WAS lbs, V102= BOD primary effluent lbs, V131= BOD effluent lbs

(V50*8.34*V2)/0.167

Where: V50=Influent BOD, V2=Influent flow

1.8 * V92 + 32

Where: V92 is Influent Water Temperature {C}

(V91 -32) / 1.8

Where: V91 is Influent Water Temperature {F}

V2 * 0.00144

Where: V2 is Flow {GPM}

(1.23*7.48*24) / V7

Where: 1.23 is Tank Volume in Cu Ft

7.48 is gal/Cu Ft

24 is hours in day

V7 is Flow in gals/day

(V1021*1.23*8.34) - (V11 * V1 * 8.34) / V1071

Where:

V1021 = MLSS

1.23 = Aeration Volume

8.34 = lbs/gal

V11 = Inf BOD

V1 = Inf Flow

V1071 = Target F:M

See calculating percent removal for more information on percent removal calculations.

(V11 - V4011) / V11 * 100

Where:

V11=Inf BOD

V4011=Eff BOD

Solids Loading Rate in lbs/sqft = MLSS{mg/L} X (Inf Flow{MGD} + RAS FLow{MGD}) X 8.34{lbs/gal} / Clarifier Surface are in Sq Ft

(V1021 (V1+V1001)8.34) / V4065

Where:

V1021 = MLSS

V1 = Inf Flow

V1001=Ras Flow

8.34 = lbs/gal

V4065 = Clarifier Surface area in Sqft

V14 / 890

 

V14 = Flow in gpd

890 = Surface area in SqFt

Chlorine Demand in mg/L = Chlorine Dose{mg/L} - Chlorine Residual{mg/L}

V4062 - V4063

Where:

V4062 = Chlorine Dose

V4063 = Chlorine Residual

Lab:  Seeded BOD {mg/L} = (Initial DO{mg/L} - Final Do{mg/L}) - (Initial Seed Control DO{mg/L} - Final Seed Control DO{mg/L}) X Volume of Seed Added{mg/L} / Sample Volume {mL/bottle volume mL}

* Volume of Seed added is Seed Material that has been added directly to sample or to seed control bottles

(V4013-V4014)-(V4023-V4024) * 2 / 300

Where:

V4013= Eff BOD Initial DO

V4014= Eff BOD Final DO

V4023=Seed Control Sample Intial DO

V4024=Seed Control Sample Final DO

2= Volume of Seed added

300 = mL / bottle

Lab:  Suspended Solids in {SS} mg/L = Weight of Filtered dry Solids{mg} - Weight of the filter{mg} / Sample volume{ml}X 1000000

 

* See Custom Data Entry TSS Bench Sheet

1.08752 - 1.06619 / 100 * 1000000

Where:

1.08752 = Weight of Filter Dry and Tara Weight

1.06619 = Tara weight

100 = amount of Sample in mililiters

1000000 = Liters

Lab: Volatile Suspended Solids {VSS} mg/L = Weight of filter and Dry Solids{mg} -  Weight of Filter and Ash{mg} / Sample volume {ml} * 1000000

1.08750 - 1.0687 / 100 *1000000

Where:

1.08750 = Weight of Filter Dry and Dry Solids

1.0687 = Weight of Filter and Ash

100 = amount of Sample in mililiters

1000000 = Liters

Langelier Saturation Index = pH - pHs

 

where pHs = (9.3 + A + B) - (C + D)

 

Where:

 

A = (Log 10 [TDS] - 1) / 10  

B = -13.12 x Log10 (oC + 273) + 34.55  

C = Log10 [Ca2+ as CaCO3] - 0.4  

D = Log10 [alkalinity as CaCO3]

V101 = LSI(V102,V103,V104,V105,V106)

 

Where:

 V102: is the measured water pH
 V103: is the TDS
 V104: is the Temperature in Deg C
 V105: is the Hardness in mg/L

 V106: is the Alkalinity in mg/L


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Created on 2/19/2008 2:15 PM.
Last Modified on 3/29/2011 4:10 PM.
Last Modified by Scott Dorner.
Article has been viewed 5047 times.
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