For future future flow flow : Q av /day , Q max av = 65000 m /day max = 1.6 Q av av
Calculate the following:
•
Dimension of main collection sump.
•
Diameter of rising pipe.
•
Flow rate and total total head of pumps, knowing knowing that two pumps will pump the flow from elevation 10 to elevation 25m above sea level for a distance of 1200m.
Beirut Arab University
Fourth Year
Faculty of Engineering
Fall 2012-2013
Dept. of Civil Engineering
Wastewater Engineering-CIVE434
Sheet -61- Sewer lines ABCDE, shown in figure
A
B
30m 15l/s
C
30m
30l/s
D
30m
45l/s
E
30m
45l/s
75l/s
Calculate diameter and slope of lines AB, BC, CD, and DE, considering the following that Sewer flow rate = 0.7 water depth of pipe diameter at Q max = 2 Q av Line AB: Q max = 2 Q av Q max = 2 x 15 = 30 l/sec
- d/Dfull = 0.7, then from chart Qmax / Qfull = 0.85 & Vmax / Vfull= 1.15 - Q full = Qmax / o.85 = 30 / 0.85 = 35.3 l/sec . - S = 0.005 From nomogram D = 150 mm
Beirut Arab University
Fourth Year
Faculty of Engineering
Fall 2012-2013
Dept. of Civil Engineering
Wastewater Engineering-CIVE434
Sheet -73
1- For flow rate = 90000 m /d, calculate dimensions of the following: -Screens -Grit chamber -Primary sedimentation tank
3
2- Small community has a discharge of 50000 m /d, and has a Primary Treatment Plant, in raw waste water BOD=300ppm. A- Activated sludge B- Extended aeration tank C- Oxidation ditch i- Calculate the number and dimensions of each type. ii- Calculate dimensions of final settling tank, and volume of sludge.
Beirut Arab University
Fourth Year
Faculty of Engineering
Fall 2012-2013
Dept. of Civil Engineering
Wastewater Engineering-CIVE434
Sheet -8-
1- Ten families are living in a house located away of sewerage system of the city. Septic tank are required to treat the waste water and reusing the treated water in irrigation , Design this system, if each family has 6 persons and average rate of water consumption equal 150 L/d .
2- In a rural area there are many separate houses, each one has a population of 50 persons, and rate of water consumption estimated to be 110 L/person/day, Design a complete drainage system for each house.
Beirut Arab University
Fourth Year
Faculty of Engineering
Fall 2012-2013
Dept. of Civil Engineering
Wastewater Engineering-CIVE434
Sheet -12-
A community has about 2000 persons, and rate of consumption = 200L/c/d. Design the Biological Unit for the small treatment plant.
