A factory disposes 1.1 m3/s of treated industrial wastewater into a river. The wastewater has an...

A factory disposes 1.1 m³/s of treated industrial wastewater into a river. The wastewater has an ultimate biochemical oxygen demand of 25 mg/L and dissolved oxygen of 2 mg/L. Just upstream of the wastewater outfall, the river has a flow rate of 10 m³/s, ultimate biochemical oxygen demand of 6 mg/L, and oxygen deficit of 2 mg/L. At the river temperature, the saturation concentration of dissolved oxygen is 9 mg/L. The deoxygenation coefficient is 0.19 d^-1 and reaeration coefficient is 0.11 d^-1. The velocity of the river is 0.4 m/s.

(a) What is the ultimate biochemical oxygen demand (mg/l) immediately downstream of the outfall?

(b) What is the dissolved oxygen (mg/L) immediately downstream of the outfall?

(c) What is the oxygen deficit (mg/L) 97 km downstream of the discharge point?

(d) What is the maximum oxygen deficit (mg/l) along the river, and where does it occur (km)?

Expert Solution

Ally Wells answered 1 year ago

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