With this question for wastewater treatment, i can't figure out what formulas to use!

calculate the pounds of solids under aeration of the given plant:

influent bod: 310 mg/l

influent tss: 210 mg/l

aerbay: 110' x 15' x 12 feet deep (operating level of the tank is 10')

aerbay mlss (mixed liquer suspended solids) 2,800 mg/l

effluent bod: 2.5 mg/l

effluent tss: 1.5 mg/l

2884.17 lbs

Explanation:

Data provided:

Influent BOD = 310 mg/l

Influent TSS = 210 mg/l

Dimensions of Aerbay = 110' × 15' × 12'

Operating level of the tank = 10'  

thus,

The operating volume of aerbay = 110 × 15 × 10 =  16500 ft³

also,

1 ft³ = 7.48052 gallons

Thus,

16500 ft³ = 16500 × 7.48052 gallons = 123428.58 gallons  

Now,

Aerbay MLSS (mixed liquor suspended solids) = 2,800 mg/l

Therefore,

Pounds of solids under aeration

= Operating volume of aerbay × concentration of aerbay MLSS

also,

1 mg/L = 8. 3454 × 10⁻⁶ lbs/gallon

thus,

Pounds of solids under aeration

= 123428.58 gallons × ( 2800 × 8. 3454 × 10⁻⁶ lbs/gallon )

or

= 2884.17 lbs