A city discharges 25 MLD domestic sewage into a stream whose average flow is 185 MLD. The velocity of the stream is 2 km/hr. The temperature of both the stream and sewage is 20 °C. The 20 °C BOD5 of the sewage is 80 mg/L, while that of the stream is 1.2 mg/L. The sewage contains no DO, and the stream is 90% saturated upstream of the discharge. At 20 °C, kl, k2, and saturated oxygen concentration is 0.34 per day, 0.65 per day, and 9.1 mg/L respectively. Find the time and distance downstream at which the oxygen deficit is a maximum.

A city discharges 25 MLD domestic sewage into a stream whose average flow is 185 MLD. The velocity of the stream is 2 km/hr. The temperature of both the stream and sewage is 20 °C. The 20 °C BOD5 of the sewage is 80 mg/L, while that of the stream is 1.2 mg/L. The sewage contains no DO, and the stream is 90% saturated upstream of the discharge. At 20 °C, kl, k2, and saturated oxygen concentration is 0.34 per day, 0.65 per day, and 9.1 mg/L respectively. Find the time and distance downstream at which the oxygen deficit is a maximum.

Structural Analysis

6th Edition

ISBN:9781337630931

Author:KASSIMALI, Aslam.

Publisher:KASSIMALI, Aslam.

Chapter2: Loads On Structures

Section: Chapter Questions

Problem 1P

See similar textbooks

Related questions

Q: A municipal wastewater flow of 1,000 m³/d contains 400 mg/L BOD5 and is treated to be in a trickling…

Q: It is estimated that the BOD of raw sewage received at a treatment plant serving a population 20,000…

Q: A city of 50,000 people deposits 30.0 cfs (cubic ft per second) of sewage with a BOD of 101.0 mg/L…

Q: A municipal wastewater flow of 1,000 m³/d contains 400 mg/L BOD5 and is treated to be in a trickling…

Q: 26. An Extended Aeration treatment plant consists of an aeration compartment with a volume of 1320…

A: Calculate the F/M ratio and the volumetric loading.?

Q: A domestic wastewater with BODs of 205 mg/L is treated by a secondary treatment plant that removes…

A: Given, BOD5 = 205 mg/L Initial DO = 9.2 mg/L Final DO = 2 mg/L Bottle volume = 300 ml

Q: A detention pond receives wastewater having a constituent concentration of 500 mg/L. A discharge…

A: Solution Given Data constituent Concentration = 500 mg/L Discharge concentration= 100 mg/L Flow…

Q: The chloride concentration in a brine waste flow of 6.3 L/s is 15000 mg/L. The river flow upstream…

A: step 1-

Q: At the point of mixing of a river and a wastewater point discharge, DO is 5.5 mg/L and DOs is 10.1…

A: It is required to find critical deficit of DO and minimum DO. Critical time of DO deficit and…

Q: A factory is discharging its wastewater into a slowly moving stream that has a mean velocity of 3…

A: Dissolved oxygen sag curve

Q: A city of 5000 persons is to be served by a low rate trickling filter with a synthetic packing (K =…

A: Wastewater treatability and packing coefficient, K= 2.2 constant characteristic of packing used,…

Q: The stream shown below has a flow of 28,000 m³/d, and a cross-sectional area of 35 m². The stream is…

A: k1=0.18/day for BOD assimilation in the riverk3=0.01/day for BOD sedimentation in the…

Q: Three streams are mixing at a junction. The flow rate and total dissolved solids (TDS, a…

Q: You have a DAF with wastewater flow of 650 L/min, with a solids concentration of 15 g/L. Density of…

A: Given: Wastewater flow rate, Q = 650L/min Solids concentration = 15g/L Density of the wastewater =…

Q: Wastewater with DO concentration of 2 mg/L is discharged to a river. The temperature of the river is…

Q: A lagoon with a volume of 1500 m3 reieves an industrial wastewater flow of 100 m3/day containing a…

A: Volume = 1500 m3 Waste water flow = 100m3/day Concentation = mg/l

Q: 2. A lake has a volume of 9 million m³ and an average depth of 3 m. There is an influent stream…

Q: A primary wastewater treatment uses centrifugation for dewatering of primary sedimentation sludge.…

A: Given :- Average daily flow to the treatment plant = 5000 m3/d Total suspended solids in raw waste…

Q: A municipal wastewater flow of 1,000 m³/d contains 400 mg/L BOD5 and is treated to be in a trickling…

Q: The City of Smyrna discharges 0.16 m3/s of treated wastewater into Chattahoochee River. The BOD5 for…

A: Discharge of sewage Qs=0.16 m3/s Discharge of river, QR=0.16 m3/s BOD5 of sewage, =30 mg/L BOD5 of…

Q: Drainage from a former pesticide manufacturing site enters Bear River at river kilometer 240. The…

A: Cin = 5 μgm/L P = 15000 t1/2 = 70 days V = 5 cm/s or 0.05m/s

Q: An activated sludge tank is 30 m long and 10 m wide and has an SWD of 4 m. The wastewater flow is…

Concept explainers

Integrated Solid Waste Management

Integrated Solid Waste Management (ISWM) is a thorough waste suppression, compost, removal and recycling Program. An effective ISWM system considers how to suppress, manage and recycle solid waste in a manner that is most efficiently to protect human health and the surrounding. ISWM system requires evaluation of public wants and demands and then selecting and merging the most effective waste management activities for the proposed demands. The main ISWM activities for solid waste management are Waste prevention, Recycling and Composting, and Combustion and Removal and waste collection in a properly planned, constructed, managed and mitigated landfill areas. Each of these requires careful designing, financing, accumulation, and delivery of activities.

Question

A city discharges 25 MLD domestic sewage into a stream whose
average flow is 185 MLD. The velocity of the stream is 2 km/hr.
The temperature of both the stream and sewage is 20 °C. The 20 °C
BOD5 of the sewage is 80 mg/L, while that of the stream is 1.2
mg/L. The sewage contains no DO, and the stream is 90% saturated
upstream of the discharge. At 20 °C, kl, k2, and saturated oxygen
concentration is 0.34 per day, 0.65 per day, and 9.1 mg/L
respectively.
Find the time and distance downstream at which the oxygen deficit
is a maximum.
Find the minimum value of DO.

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1:Introduction

VIEW

Step 2:Calculation of maximum and minimum oxygen deficit

VIEW

Step 3: Calculate the Maximum Value of DO

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 3 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.

Similar questions

A pharmaceutical wastewater needs a minimum BOD/N/P of 100/3.0/0.7 for biological treatment. The wastewater characteristics are BOD = 740 mg/l, suspended solids = 250 mg/l, soluble nitrogen = 10 mg/l, and soluble phosphorous = 5 mg/l. What ammonium nitrate and phosphoric acid additions would you recommend to ensure adequate nutrients for a daily flow of 28 m3/d?
The lowest flow in the Ozama River in July is about 48 m3/s. The dissolved oxygen concentration of the river just upstream of the discharge point is 4 mg/l and the ultimate BOD of the river is 10 mg/l. A farm discharges 2m3/s of untreated wastewater with a dissolved oxygen concentration of 0.5 mg/l and an ultimate BOD of 300 mg/l. Both the river and the discharge are at 25°C. what is the initial oxygen deficiency after mixing (i.e., as soon as the wastewater and the river have mixed)? What is the ultimate initial BOD after mixing? Can the farm be allowed to continue discharging raw water? Justify your answer.
An industry generates 4 million gallons per day (MGD) (that is 15,000 m^3/ day) of liquid industrial wastewater having BOD5 of 1000 mg/L and first order reaction rate constant of 2.0/day. Because of the high BOD, there is a plan to build an industrial pre-treatment system at an industrial park. Effluent from the pre-treatment will be discharged into the city sewer for final polishing at the city wastewater treatment plant. Determine: a. Percent BOD removal if the wastewater is treated in one 5000 m^3 continous flow stirred tank reactor. b. Percent BOD removal if the wastewater is treated in one 5000 m^3 plug flow reactor. c. Percent BOD removal if the wastewater is treated in one 2500 m^3 continous flow stirred tank reactor followed by one 2500 m^3 plug flow reactor. d. Percent BOD removal if the wastewater is treated in one 2500 m^3 plug flow reactor followed by one 2500 m^3 continous flow stirred tank reactor. e. Percent BOD removal if the wastewater is treated in one 2500 m^3…
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?
You are constructing a sewage lagoon with a 3,100 m3/day inlet/outlet flow rate. You must attain a BOD outflow load of 12 mg/L given a BOD inlet load of 26 mg/L. BOD has a half-life of 2.4 days.What volume is needed for the lagoon and how long would it take for the output BOD concentration to reach 1 ppm if freshwater started to replace the wastewater that was previously entering the lagoon?