To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of_______________?

Related Mcqs:

1. For the COD test of sewage, organic matter is oxidised by K2Cr2O7 in the presence of________________?

   A. H2SO4 B. HNO3 C. HCl D. None of these...

2. In sewage having fully oxidised organic matter, the nitrogen exists in the form of________________?

   A. Nitrites B. Nitrates C. Free ammonia D. Aluminoid nitrogen...

3. If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is_________________?

   A. 100 mg/l B. 200 mg/l C. 300 mg/l D. 400 mg/l...

4. If the depletion of oxygen is found to be 5 ppm after incubating a 2.5% solution of sewage sample for 5 days at 21°C, B.O.D. of the sewage is_____________________?

   A. 50 ppm B. 100 ppm C. 150 ppm D. 200 ppm...

5. If the depletion of oxygen is found to be 2.5 mg/litre after incubating 2.5 ml of sewage diluted to 250 ml for 5 days at 20°C, B.O.D. of the sewage is_________________?

   A. 50 mg/l B. 100 mg/l C. 150 mg/l D. 250 mg/l...

6. 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...

7. The sewage treatment units in which anaerobic decomposition of organic matter is used, are called________________?

   A. Imhoff tanks B. Trickling filters C. Sludge sedimentation tanks D. None of these...

8. The density of population over 40 hectares is 250/hectare. If water supply demand per day is 200 litres and sewage discharge is 80% of water supply, the sewage flow in sewers of separate system, is_____________________?

   A. 0.05552 cumec B. 0.05554 cumec C. 0.05556 cumec D. 0.0556 cumec...

9. Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to_______________?

   A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these...

10. Lead acetate test in sewer manhole is done to test the presence of ____________________?

    A. Methane gas B. Hydrogen sulphide C. Carbondioxide gas D. Diesel vapours...