Question

A 2-liter graduated cylinder was used to determine the SVI of an acti- vated sludge sample. The settled volume was 850 mL and the MLSS was 3,000 mg/L. What was the SVI?

a. 283 mL/g
b. 850 mL/g
c. 425 mL/g
d. 142 mL/g

Answer 1

The Sludge Volume Index (SVI) is calculated as 283.33 mL/g by dividing the settled volume by the MLSS concentration, which results in option (a) 283 mL/g when rounded to the nearest whole number.

Step-by-step explanation:

The question is related to calculating the Sludge Volume Index (SVI), which is a concept used in environmental engineering to indicate the volume of sludge settled in a certain amount of time.

To find the SVI, we use the formula SVI = (settled volume in mL/L) / (mixed liquor suspended solids (MLSS) in g/L). Given data states the settled volume is 850 mL and the MLSS concentration is 3,000 mg/L, or 3 g/L.

By substitution, we would get SVI = 850 / 3 = 283.33 mL/g. If we round this number to the nearest whole number, we get 283 mL/g, which is option (a).