A city discharges 100 cumecs of sewage into a river, which is fully saturated with oxygen and flowing at the rate of 1500 cumec during its lean days with a velocity of 0.1 m/sec. The 5 days BOD of sewage at the given temperature is 280 mg/1. Assume coefficient of purification of the stream (f) as 4.0 and coefficient of deoxygenation (ko base 10) is 0.1 day1. The critical dissolved oxygen deficit is the river is: [Assume D0 of sewage is nil.] [Take river water dissolved oxygen as 9.2 mg/1]

A city discharges 100 cumecs of sewage into a river, which is fully saturated with oxygen and flowing at the rate of 1500 cumec during its lean days with a velocity of 0.1 m/sec. The 5 days BOD of sewage at the given temperature is 280 mg/1. Assume coefficient of purification of the stream (f) as 4.0 and coefficient of deoxygenation (ko base 10) is 0.1 day1. The critical dissolved oxygen deficit is the river is: [Assume D0 of sewage is nil.] [Take river water dissolved oxygen as 9.2 mg/1]

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

See similar textbooks

Similar questions

Population equivalent.
A bottle is filled with river water. The initial dissolved oxygen concentration is 10.2 mg/L. After 5 days the dissolved oxygen concentration is 3.0 mg/L. Calculate the BOD 5. in mg/l
If the BOD of a municipal wastewater at the end of 7 days is 60 mg/L and the ultimate BOD is 85.0 mg/L, what is the first order reaction constant?
A 2% sewage sample (in distilled water) was incubated for 3 days at 27°C temperature. After incubation, dissolved oxygen depletion of 10 mg/Lwas recorded. The biochemical oxygen demand (BOD) rate constant at 27°C was found to be 0.23 day^-1 (at base e). What is the ultimate BOD (in mg/L) of the sewage?
A trickling filter with a volume of 250 m3 is used to treat wastewater with flowrate 30,000 m3/d and BOD5 of 130 mg/L. The OLR in peak conditions is 1.6 times that of average conditions. Calculate the required oxygen supply per unit mass of BOD.
A city discharges 100 cumecs of sewage into a river, which is fully saturated with oxygen and flowing at the rate of 1500 cumecs during its lean days with a velocity of 0.1 m/sec. The 5-days BOD of sewage at the given temperature is 280 mg/l. Find when and where the critical D.O. deficit will occur in the downstream portion of the river, and what is its amount. Assume coefficient of purification of the stream (f) as 4.0, and coefficient of deoxygenation (KD) as 0.1.
A sample of diluted wastewater (diluted 10 times) has a 5-day biological oxygen demand (BOD) of 5 mg/L. If the rate constant is 0.1/d, assuming a first-order chemical reaction, the ultimate BOD of the original wastewater is most nearly (A) 0.50 mg/L (B) 5.0 mg/L (C) 13 mg/L (D) 130 mg/L
A city wishes to discharge wastewater primary effluent to a river which supports a trout. The state requires the city to show that the trout population is protected. Trout require a minimum of 4 mg/l of dissolved oxygen to survive. Determine the minimum downstream dissolved oxygen concentration from the following information about the wastewater discharge and river. Does the minimum dissolved oxygen concentration meet the requirements? Wastewater discharge=0.45m3/s, river flow rate= 8.5 m3/s, river cross-sectional area=19m2, dissolved Oxygen concentration in the wastewater= 0.2mg/l, dissolved oxygen content of the river upstream = 8.1mg/l, saturation dissolved oxygen concentration at 20 C= 9.0 mg/l, BOD concentration in wastewater = 85 mg/l, BOD concentration upstream in the river= 0.2 mg/l, BOD decay constant = 0.2 d-1, and the reaeration constant for the river= 0.4 d-1.
At a small water treatment plant which has 4 filters, the rates of filtration and backwashing are 200 m³/d/m² and 1000 m³/d/m² respectively. Backwashing is done for 15 min per day. The maturation, which occurs initially as the filter is put back into service after cleaning, takes 35 min. It is proposed to recover the water being wasted during backwashing and maturation. The percentage increase in the filtered water produced (up to two decimal places) would be
The treated waste water is being discharged into a river that has a temperature of 15°C. The BOD rate constant determined in the laboratory for this mixed water is 0.12 per day (base e) at 20°C (Temperature coefficient, 1.047). What fraction of maximum oxygen consumption will occur in first four days?
The density of water at 4°C is 1000 kg/m3 at atmosphericpressure. The gravity acceleration constant (g) is 9.81 m/s2. Thespecific gravity of an industrial wastewater (SGww) is 1.32. Whatis the specific weight of this wastewater?