Problem Solved: BOD Problem - Wastewater Math

americanwaterco...
This question comes from the California Wastewater grade 3 certification exam sample questions that can be found here: www.swrcb.ca.go...
The problem reads:
A secondary effluent has a total BOD of 45 mg/L. A BOD5 test is run on this same secondary effluent at the same time using a nitrification "inhibitor". Using the data for this test is given below, calculate the nitrogenous BOD (Assume a 300 mL BOD bottle is used to run this test).

[@SharpShootr92]

11 years later and you're still helping people. thank you!!

[@AmericanWaterCollege]

The blank depletion should be 0.2 mg/L or less while the sample bottle depletion should be 2 mg/L or more, with at least 1 mg/L left in the sample bottle. Good catch! We will redo this problem. The answer doesn't change, however I did misspeak when talking about the sample bottle DO depletion.

[@suhedaylmaz1627]

American Water College hello i have a question. If we have a 10 day period and BOD values and if instructor ask “estimate rate constant and ultimate BOD using Thomas Method” which equation should we use? Because i try to solve using L_10(1-e^-k.10) but we have two unknown and i dont know what should i do, thank you :))

[@mehakakhtar9201]

pump floe rate

[@nocoho1]

I always wondered what the lecturer looked like! Taken 2 courses from American Water College so I am glad to see some videos on TH-cam before my Grade 3 test.

[@troyrieder5927]

Calcium Chloride, Magnesium Sulfate, Ferric Chloride and Phosphate Buffer are added to the nutrient buffer solution.

[@MrJohnAndrewhall]

I always thought (was told) they used a 7 day BOD in America. The 5bdaybwas particular to the UK because that, supposedly, was the max. time it took for any river in the UK to flow from source to sea.

[@MasterCivilEngineering]

Step by step video solutions for civil engineering questions

[@odirilep]

Thanks, the 0.2 mg/l and 2.0 mg/l is well explained. these vedios are very useful. well done.

[@AmericanWaterCollege]

I'm happy you are experiancing success using all the tools available through American Water College to advance your certification. Keep up the good work. I wish you success on your grade 3 exam. -Joe

[@juanfranmar1225]

Muy clara la explicación, me ayudó mucho para operar mi planta de tratamiento, muchos de sus vídeos lo son. Saludos !

[@abasin08]

Yesterday I took my wastewater B exam for the state of Colorado, and saw a BOD problem with sample dilution, how would you go about with sample dilutions with BOD?
Thank you.

[@sholaraja]

Thank u very much.ur videos very useful to me.keep adding

[@alexanderpanama8861]

Did you have refference book

[@chunhengong6581]

i want to know the chemicals used for the nutrients

[@TheAhmedbenali]

thank you

[@PhotonCherades]

Well done!

[@sholaraja]

depletion should be 0.2 or 2mg/l?please clarify

[@gmwwc]

Build a spreadsheet. This is too tedious to do by hand. Also writing your own spreadsheet with conditional formatting will acquaint you with the formula on a very personal level.
or cheat and download one from one of the reagent suppliers.

[@Rayaann]

THANKS SOO MUCH YOU REALLY HELPED IN MY MATH AT SCHOOL

[@sholaraja]

in the sample

[@A.Goni_Chemist-1986]

wow good vedio which is very effective

[@thyaisrobinson5657]

i got 17.5mg/l

[@mitapervin4842]

Bod discussion den

[@A.Goni_Chemist-1986]

wow good vedio which is very effective