# Civil Engineering - Waste Water Engineering - Discussion

### Discussion :: Waste Water Engineering - Section 1 (Q.No.4)

4.

If 2% solution of a sewage sample is incubated for 5 days at 20°C and depletion of oxygen was found to be 5 ppm, B.O.D. of the sewage is

 [A]. 200 ppm [B]. 225 ppm [C]. 250 ppm [D]. None of these.

Explanation:

No answer description available for this question.

 Md Seraj said: (Feb 26, 2014) D.O consume = 5 ppm. Dilution factor = 100/2 = 50. B.O.D of the sewage = 5*50 = 250 ppm.

 Satya said: (Dec 24, 2014) 2% solution bod 5 ppm. 100% solution 100/2*5 = 250 ppm.

 Nilima said: (Jan 3, 2015) Dilution ratio = 100/% of solution. = 100/2. = 50. B.O.D = 5 x 50 = 250 ppm.

 Dinesh Sharma said: (Jan 26, 2015) BOD = Oxygen consumed x dilution factor. So, BOD = 5x100/2 = 250ppm.

 Roshan said: (Mar 2, 2015) P = Dilution factor = Fraction of waste water in the sample of 300 ml BOD bottle = 2/100 = 0.02. BOD = Oxygen consumed/P = 5/0.02 = 250 ppm.

 Asaithambi said: (Sep 22, 2016) Considering total quantity of sewage =100%, solution of sewage = 2%(sample), depletion of oxygen = 5ppm. Dilution factor = 100/2 = 50. B.O.D = 50 * 5 = 250ppm.

 Santanu said: (Mar 5, 2017) BOD = (DO initial - DO final) x dilution ratio. = 5 x (100/2). = 250ppm.

 Nahid Farjana said: (Sep 26, 2017) DF= 2%= 0.02. DO= 5ppm, BOD= consumed DO/DF. = 5/0.02= 250.

 Noushin said: (Mar 1, 2018) Given, Depletion of oxygen=5ppm Solution of sewage=2% Consider, Total quantity of sewage= 100% We have, BOD = (DO initial -DO final) * Dilution factor. Dilution factor =(Vol of diluted sample/Vol of in diluted sewage sample). DO initial-DO final means depleted oxygen content. Therefore, BOD = 5 * (100/2) = 250ppm.

 Bujjibabu said: (Mar 19, 2018) BOD=(DO intial - DO final) *Dilution factor. Dilution factor=100/% of solution, So, DF=100/2 = 50, BOD=5*50 = 250.

 Raaj said: (Aug 19, 2018) Thank you all for explaining it.

 Uday Kumar said: (Nov 2, 2018) BOD = D.F * DO consumed. D.F. = 100/%of solution, D.F. = 50, BOD = 5 * 50 = 250 ppm.

 Robin said: (May 3, 2019) Oxygen Depletion = DOi - DOf = 5 ppm (Given). Decimal fraction = 0.02 (Given). BOD = (DOi - DOf)/P. So, BOD = 5/0.02 = 250 mg/L.

 Bruno said: (Dec 30, 2019) (Initial do - final do )*dilution factor. 5*50 = 250.

 Tyson said: (Jan 6, 2020) P = Dilution factor = Fraction of waste water in the sample of 300 ml BOD bottle = 2/100 = 0.02. BOD = Oxygen consumed/P = 5/0.02 = 250 ppm.