# question need in 4 hours

A 4 MGD WWTP discharges a secondary treated effluent into a receiving stream. The wastewater has the following characteristics:
BOD5= 20 mg/L
DO = 2.0 mg/L
Water Temperature = 24C
The receiving upstream from the point of discharge has the following characteristics:
Flowrate = 18 cfs
BOD5= 4 mg/L
DO= 6 mg/L
Water Temperature = 27C
Cross-sectional Area = 36 sqft
a. 3.2
b. 5.2
c. 7.2
d. 8.4
The reaeration rate is estimated to be 0.4 1/day. (Base e at 20C), and the temperature correction coefficient is 1.024. the deoxygenation rate
constant is estimated to be 0.23 1/day. (Base e at 20C) and the temperature correction coefficient is 1.047. reaeration and deoxygenation are
the only major factors affecting the dissolved oxygen concentration in the stream after mixing with wastewater effluent. Assume the time of
travel in the stream to reach the maximum dissolved oxygen deficit is 3 days. The dissolved oxygen deficit (mg/L) at this location downstream
from the point of discharge is most nearly: WE WRITE ESSAYS FOR STUDENTS  