1. Samples for making laboratory tests on wastewater should be _. a. Collected when possible during the day b. Representative of the wastewater to be tested c. Collected at a convenient location in the plant d. Collected only after the final treatment unit 2. Proper sample collection techniques are specified in _. a. Standard Methods…
1. What is the chlorinator setting, in pounds per day, to treat a flow of 5,500,000 gpd if the chlorine dosage is 5 mg/L? 2. If the flow rate in the problem above is increased to 6,300,000 gpd, how many more pounds per day would be needed (assuming the same dosage rate). 3. If a…
1. An analytical balance is sensitive to the nearest _. a. Milligram b. 1/1,000 mg c. 1/100 mg d. 1/10 mg 2. An Imhoff cone is used to determine _. a. pH b. chlorine residual c. settleable solids d. SS 3. A burette is used to _ a sample. a. Heat b. Titrate c. Filter…
1. In wet oxidation processes an increase in oxidation is due primarily to reacting the sludge with greater quantities of oxygen at elevated temperatures and pressures. 135 a. true b. false 2. Chemical stabilization of sludge finds application at over loaded plants and at plants experiencing stabilization facility upsets. a. true b. false 3. Sludge…
1. If an activated sludge plant discharges 1,500,000 gpd of wastewater with a BOD concentration of 15 mg/L, how many pounds of BOD are discharged each day? 2. If a trickling filter plant receives an influent total suspended solids of 250 mg/L with a flow of 880,000 gallons per day, what would the TSS loading…
1. Stabilized organic material usually gives off obnoxious odors. a. true b. false 2. When doing a 30-minute activated sludge settleability test, a 1000-mL imhoff cone should be used.. 1. true 2. false 3. Dissolved air floatation thickeners that treat primary sludge should be equipped with bottom sludge scrappers and sludge removal equipment. a. true…
Lab results for following problems Influent BOD – 250 mg/L Influent TSS – 264 mg/L Primary clarifier effluent BOD – 160 mg/L Primary clarifier effluent TSS – 112 mg/L Final clarifier effluent BOD – 10 mg/L Final clarifier effluent TSS – 25 mg/L 1. Find overall plant efficiency for TSS 2. Find activated sludge/final clarifier…
1. What is the detention time, in hours, of a clarifier that is 40 ft in diameter, 12 feet deep and receives a flow of 1.11 MGD? Lab Results for remaining 4 problems: Influent BOD = 225 mg/L Influent TSS = 238 mg/L Primary Effluent BOD = 153 mg/L Primary Effluent TSS = 114 mg/L…
1. Jar tests should be followed by on-site tests for more accurate results. a. true b. false 2. Lime stabilization results in a greater volume or mass of sludge a. true b. false 3. Foaming in aerobic digesters is a common problem that is easily corrected by reducing the dissolved oxygen level in the digester….
1. A rectangular clarifier is 75 feet long, 22 feet wide, and 10 feet deep. If it receives a flow of 1,250,000 gallons per day, what is the detention time in hours? 2. A rectangular secondary clarifier is 60 feet long, 30 feet wide and 8 feet deep. If the flow into the clarifier is…
