Streamline - Summer 2013 - (Page 43)
BY DONNA LAWSON, WASTEWATER TECH II
A wastewater treatment plant treats
1,500,000 gpd with a 12.5% sodium
hypochlorite solution. If the necessary
feed rate dose is 3.0 mg/L and the
specific gravity of the hypochlorite is
1.03, how many gallons per day of
sodium hypochlorite are required?
What is the F/M ratio for a treatment plant that treats a flow of
2.0 MGD with a BOD concentration
of 150 mg/L and an aeration basin with
a volume of 1.85 MG with a MLVSS
concentration of 3,000 mg/L?
What would the motor horsepower
be if the brake horsepower is 75 HP
and the motor efficiency is 89%?
An operator fed 6.7 gallons of
saturated sodium fluoride while
treating 120,000 gallons of water over
a 24-hr period. What is the calculated
fluoride dose in mg/L?
A sedimentation basin has a weir
which is 87 feet long. Water flows
through the basin at a rate of 1.0 MGD.
What is the overflow rate in gallons per
day per foot of weir for the basin?
2.75 MGD of water was treated with
a fluoride dose of 1.0 mg/L. Find
the sodium fluorosilicate feed rate in
pounds per day. Note: AFI, decimal =
0.607 Purity, decimal = .985
A water treatment plant has four (4)
sedimentation basins. The basins
are 100 feet long, 30 feet wide and 12
feet deep. One of the basins has been
taken out for routine maintenance. Find
the surface overflow rate in gallons per
day per square foot with a daily flow
of 8.25 MGD.
A tank holds 1,000,000 gallons
and has a flow of 8 MGD flowing
through the tank. What is the detention
time in hours?
Find the operating cost ($/hr) of a
50 hp pump, if the power cost is
40 pounds of chlorine was used
to treat 3,250,000 gpd of effluent. If the chlorine residual is 0.5 mg/L,
what is the chlorine demand, mg/L?
Answers on page 44
Table of Contents for the Digital Edition of Streamline - Summer 2013
From the President
From the Executive Director
Generators – Learning from the Past
Does the End Justify the Means?
Clean Out Your Medicine Cabinet!
How is Serving on a Board of an Organization like Owning a Car?
Monitoring Master Meters
2013 Conference Highlights
OilClean from EcoSolutions Naturally Separates Oil from Water
Choosing a Rate Analyst
Ergs, Joules and Other Stuff
Snug and Smug with Solar Power
Fresh Faces: Joey Fagan
Throwing My Loop
Do You Know What Your VRWA Benefits Are?
Welcome New Members
Board of Directors
Index to Advertisers/Ad.com
Streamline - Summer 2013