Geoscience Reference
In-Depth Information
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EXAMPLE 2.36
Problem:
One million gallons per day equals how many cubic feet per second (cfs)?
Solution:
6
6
3
10
1day
10
gal
×
×
0 1337
.
, 400
ft/gal
133 700
86 400
,
,
1
MGD
=
=
=
=
1 547
.
cfs
1
day
86
s/day
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EXAMPLE 2.37
Problem:
A 10-gal empty tank weighs 4.6 lb. What is the total weight of the tank filled with 6 gal
of water?
Solution:
Weight of water = 6 gal × 8.34 lb/gal = 50.04 lb
Total weight = 50.04 + 4.6 lb = 54.6 lb
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EXAMPLE 2.38
Problem:
The depth of biosolids applied to the biosolids drying bed is 10 in. What is the depth in
centimeters (2.54 cm = 1 in.)?
Solution:
10 in. = 10 × 2.54 cm = 25.4 cm
2.10 THRESHOLD ODOR NUMBER (TON)
The environmental practitioner responsible for water supplies soon discovers that taste and odor
are the most common customer complaints. Odor is typically measured and expressed in terms of a
threshold odor number
(TON), the ratio by which the sample has to be diluted with odor-free water
for the odor to become virtually unnoticeable. In 1989, the USEPA issued a Secondary Maximum
Contaminant Level (SMCL) of 3 TON for odor.
Note:
Secondary Maximum Contaminant Levels are parameters not related to health.
When a dilution is used, a number can be devised in clarifying odor.
VV
V
T
P
TON(threshold odor number) =
(2.3)
T
where
V
T
= Volume tested
V
P
= Volume of dilution with odor-free distilled water
For
V
P
= 0, TON = 1 (lowest value possible)
For
V
P
=
V
T
, TON = 2
For
V
P
= 2
V
T
, TON = 3
⋮
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EXAMPLE 2.39
Problem:
The first detectable odor is observed when a 50-mL sample is diluted to 200 mL with
odor-free water. What is the TON of the water sample?
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