A wastewater treatment plant (WWTP) discharges its effluent in a river. The regulatory agency wishes to ensure that the DO level five (5) kilometres downstream and beyond from the WWTP is at least equal to 4.2 mg/L. Use the information provided in Table 1.1 to assist the agency in its environmental management. Table 1.1 Parameter values under current conditions Value Parameter Water temperature (°C) Effluent flow from the WWTP (m³/d) River flow upstream of plant (m/s) DOsat at 25°C (mg/L) DO in effluent from the WWTP (mg/L) DO upstream WWTP (mg/L) ka at 20 °C (d) k, at 20°C (d) River velocity, v (m/s) Ultimate BOD in river upstream WWTP, Lo(mg/L) Ultimate BOD in effluent from WWTP, Lo (mg/L) 25.0 17360 0.43 8.38 1.0 6.5 0.458 0.478 0.10 0.0 15.0 a. Compute the DO and the initial ultimate BOD after mixing. b. Compute the initial DO deficit after the effluent mixes with the river. c. Compute the DO concentration five (5) kilometres downstream from the WWTP. d. Determine whether or not the WWTP treatment level satisfies the requirements of the regulatory agency.

A wastewater treatment plant (WWTP) discharges its effluent in a river. The regulatory agency wishes to ensure that the DO level five (5) kilometres downstream and beyond from the WWTP is at least equal to 4.2 mg/L. Use the information provided in Table 1.1 to assist the agency in its environmental management. Table 1.1 Parameter values under current conditions Value Parameter Water temperature (°C) Effluent flow from the WWTP (m³/d) River flow upstream of plant (m/s) DOsat at 25°C (mg/L) DO in effluent from the WWTP (mg/L) DO upstream WWTP (mg/L) ka at 20 °C (d) k, at 20°C (d) River velocity, v (m/s) Ultimate BOD in river upstream WWTP, Lo(mg/L) Ultimate BOD in effluent from WWTP, Lo (mg/L) 25.0 17360 0.43 8.38 1.0 6.5 0.458 0.478 0.10 0.0 15.0 a. Compute the DO and the initial ultimate BOD after mixing. b. Compute the initial DO deficit after the effluent mixes with the river. c. Compute the DO concentration five (5) kilometres downstream from the WWTP. d. Determine whether or not the WWTP treatment level satisfies the requirements of the regulatory agency.

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

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