WATER QUALITY - Water Quality Engineering in Natural Systems - page 26

2.2. At what temperature does the saturation concen-
tration of dissolved oxygen in water fall below the
minimum desirable level of 5 mg/l?

of incubation and can be described by the same
exponential function as the carbonaceous BOD
(CBOD). If the rate constant is 0.1 d −1 and the
5-day BOD is 20 mg/l, estimate the total BOD
after 20 days and the ultimate BOD.

2.3. A BOD test on an industrial wastewater indicates
that the 5-day BOD is 49 mg/l and that the ulti-
mate carbonaceous BOD is 75 mg/l. Estimate the
decay factor.

2.5. What are the water-quality criteria for the state in
which you live?

2.4. Analyses of an industrial wastewater indicate that
nitrogenous BOD (NBOD) begins after 10 days