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In the Streeter-Phelps model, the oxygen deficit is defined as: Select one: a. T

ID: 701569 • Letter: I

Question

In the Streeter-Phelps model, the oxygen deficit is defined as: Select one: a. The departure of the ambient DO concentration from saturation. b. The difference between the predicted saturation DO in water at the temperature of the river and the saturation DO in water at 20°C. c. The difference between the predicted saturation DO in water at the temperature of the river and the saturation DO in water at 4°C, which is the the maximum saturation DO. d. The departure of the lowest DO concentration in the river from saturation in response to the BOD input.

Explanation / Answer

The rate of reaeration (rR ), is defined as-

rR = -kR*D

where,

kR = reaeration time constant

= kR,20°C = 3.9u1/2/H3/2 ......................................................................(I)

u = average stream velocity

H = average stream depth

D = DO deficit

= DOs  - DO

here, DOs = dissolved oxygen concentration at saturation, a function of temperature, salinity, and atmospheric

  pressure (mg/L)

DO = dissolved oxygen concentration (mg/L).

clearly, option (b) is correct.

I hope you can understand the explanation.

thank you!!