GATE ES topic:water-wastewater-quality-parameters PYQs & Answers

Questions 1–4 of 4. Imported answers require independent review unless marked reviewed.

Which of the following options is/are CORRECTLY listing the species included in Total Kjeldahl Nitrogen (TKN) estimation of an aqueous sample?

Your answerSelect all correct options. You can choose more than one.

Ammoniacal – N

Nitrite – N

Nitrate – N

Organic – N

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The Streeter–Phelps oxygen sag equation for a river is based on a few assumptions. The correct assumption(s) is/are

Your answerSelect all correct options. You can choose more than one.

At any instant the deoxygenation rate is direct proportional to the amount of oxidizable organic material present.

At any instant the deoxygenation rate is inversely proportional to the amount of oxidizable organic material present.

The reoxygenation rate is directly proportional to the dissolved oxygen deficit.

The reoxygenation rate and deoxygenation rate are directly proportional to the saturation concentration of dissolved oxygen.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

You are doing an experiment to find out BOD

of a wastewater. You have taken 25 mL wastewater having ultimate BOD of 75 mg/L and placed it in 300 mL BOD bottle and filled it with dilution water. The initial DO of the diluted sample is 6.5 mg/L. On the 5th day, you were not able to measure the DO due to some unavoidable circumstances. However, the DO at the end of the 7th day is found to be 1.25 mg/L. Assume all the experiments are done at the same temperature, and no biodegradable organics are present in the dilution water. The BOD

of the wastewater sample is ____________ (in mg/L, rounded off to two decimal places).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Average values of the re-aeration rate constant for river X and river Y are 0.92 per day and 1.12 per day, respectively. Average de-oxygenation rate constants for the same rivers are 0.23 per day and 0.35 per day respectively. Then, which of the following statement(s) is/are correct?

Your answerSelect all correct options. You can choose more than one.

Self-purification capacity of river Y is more than that of river X.

Self-purification capacity of river X is more than that of river Y.

River Y has higher turbulence and/or higher velocity and/or higher algal growth compared to river X.

Pollutants in river X are more biodegradable than that in river Y.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE ES topic:water-wastewater-quality-parameters PYQs

How to practice topic:water-wastewater-quality-parameters

Question 30

Question 46

Question 58

Question 45