Five kilograms of a contaminant is quickly spilled into a stream whose character

Question

Five kilograms of a contaminant is quickly spilled into a stream whose characteristics are follows: Volumetric flow rate 3 m3/s; very smooth rectangular channel 20m wide and channel slope of 0.0002. The spread of the contaminant in the direction of flow is affected by diffusion, with a longitudinal diffusion coefficient of 0.5 m2/s. The contaminant also undergoes first-order decay with a rate constant of 2 d-1.Calculate and plot the contaminant concentration as a function of downstream distance at times of 0.5 and 2 h after the spill.

Explanation / Answer

Solution :-

Given:-

Volumetric flow rate = 3m^3/s

width of channel = 20 m

Slope of a channel = 0.0002

Diffusion coefficient = 0.5 m^2/s

Also given the contaminant also undergoes first-order decay ith a rayte constant = 2d^-1

The contaminant concentration as a function of downstream distance distaance at time of 0.5 and 2h after the spill

dq/dt = rc(t) -rq(t)/V

dq/dt = 20*0.0002- 0.5*2h *d^-1

dq/dt = 19.9 - 0.1*d^-1

Based on this the curve will be as follows:-

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.