Water Treatment Processes - Mathematics and Statistics for the Environment - page 659

■ EXAMPLE 23.119
Problem: If a total of 72 oz. of calcium hypochlorite (65% available chlorine) is added to 15 gal of
water, what is the percent chlorine strength (by weight) of the solution?

Solution: Convert the ounces of hypochlorite to pounds of hypochlorite:

(72 oz.)/(16 oz./lb) = 4.5 lb chemical

%Avai lablechlorine

100

Hypochlorite (lb)

%Chlorinestrength = ×100

%Availablechlorine
100

Water (lb) + Hypochlo rite (lb)

4.5 lb × 0.65

= × 100

(15gal × 8.34lb/gal) + ( 4lb × 065 )

2.9 lb
125.1 lb

2.9 lb ××=

= ×= 100 100 2.%

+ 2.9 lb 126

23.7.9 C alCulating p erCent s trength u sing l iquid h ypoChlorite
To calculate the percent strength of a chlorine solution, we use Equation 23.93:

%Str engthof hypochlorite

100

Liquid hypochlorite(gal) × 834 . lb/gal ×

(23.93)

%Strengthof hyp ochlorite

= Hypochlorit eesol.(gal) × 834 . lb/gal ×

100

■ EXAMPLE 23.120
Problem : A 12% liquid hypochlorite solution is to be used in making up a hypochlorite solution. If
3.3 gal of liquid hypochlorite are mixed with water to produce 25 gal of hypochlorite solution, what
is the percent strength of the solution?

Solution:

%Str engthof hypochlorite

100

Liquid hypochlorite(gal) × 834 . lb/gal ×

%Strengthof hyp ochlorite

= Hypochlorit eesol.(gal) × 834 . lb/gal ×

100

12
10

x

=

× 3.3 gal × 834 . lb/gal × 25 gal × 834 . lb/gal

0 100

100 ××× ×

×

33 . 834 2 .

x =

25 834 . × 100

33 12
25

. ×

x = = 16 .%