14597-18-1P AID: 1825 | 19/06/2015

a)

Determine the flow.

Substitute 105 gal/cap-day for Influent flow and 2,300 cap for Population.

Determine the effluent from the primary clarifier.

Substitute 195 mg/L for and 33% for BOD removal.

Determine the ultimate BOD .

Here, is the biochemical oxygen demand of the sample during the 5 days of incubation period.

Substitute 130.65 mg/L for .

Show the relation to determine the total area of the ponds with a sludge storage depth of 6 ft.

Here, A is the total area of the ponds with a sludge storage depth of 6 ft, C is a constant

with a value of in USCS units and in SI units, Q is the flow, is the ultimate influent Biochemical oxygen demand (BOD) or chemical oxygen demand (COD), T is average water temperature for the pond during winter months, f is the algal

toxicity factor, and is the sulfide or other immediate chemical oxygen demand.

Substitute for C, 0.2415 MGD for Q, 192.13 mg/L for , for T, 1

for f, and 1 for .

Thus,

The total area of the ponds is

b)

Calculate the applied load.

Substitute 105 gal/cap-day for Influent flow, 2,300 cap for Population, and 130.65 mg/L

for .

Calculate the applied loading.

Substitute 263.31 lb/day for and 6.10 ac for A.

Thus,

The applied loading is .

c)

Determine the dimensions of the pond.

The length (L) to width (W) ratio of the pond is 2:1.

Calculate the width of each pond.

Here, a is the area of each single pond and n is the number of ponds.

Substitute 6.10 ac for A and 2 numbers for n.

Determine the length of each pond.

Substitute 258 ft for W.

The sludge storage depth (d) of each pond is 6 ft.

Thus,

The width of each pond is .

The length of each pond is .

The depth of each pond is .