1.A standard five-day BOD test is run using a mix consisting of four parts distilled water and one part wastewater (no seed) the initial DO of the mix is 9.0 mg/l , and the do after Five days, determined to be 1.0mg/l. what is BOD5?
2.Assume that water recharging an aquifer in 1964 had a tritium concentration of 1200 TU at that time. If this water is not mixed with other waters, predict its tritium concentration in 1970, 1980, 1990, 2000, and 2100.
3.A maximum flow rate of 6 CFS is available for a river model. This corresponds to 30,000 CFS for the prototype. What is the scale of the model in terms of the prototype size?