1. The most important reason for chlorinating effluent samples is _. a. Decreasing BOD levels and controlling odors b. Improving scum and grease removal and chemical coagulation c. Disinfection d. Decreasing SS levels 2. The chlorine residual may be determined using the reagent _. a. DPD b. EDTA c. PCBs d. Sodium thiosulfate 3. When…
1. An influent to an aeration basin averages 1,150 gpm at a BOD concentration of 125 mg/L. If the aeration basin is 125 ft long, 40 ft wide and 15 feet deep, what is its organic loading in pounds of BOD/day/1000 cuft? 2. Calculate the aeration loading in pounds of BOD/day/1,000 cuft for the following…
1. The temperature of the incubator used for a BOD test should be maintained at _. a. 20 degrees F b. 35 degrees F c. 2 degrees C d. 35 degrees C 2. What is the basic formula for determining BOD? a. Oxygen depletion of the blank minus oxygen depletion of the sample divided by…
1. An aeration basin is 90 ft long, 25 ft wide and 13 feet deep. If it receives a flow of 0.24 MGD at a BOD concentration of 225 mg/L, what is the basin’s organic loading in pounds of BOD per day per 1,000 cubic feet? 2. If an activated sludge aeration basin receives a…
1. The definition of pH is a. The negative logarithm of the relative hydrogen ion concentration b. The positive logarithm of the relative hydrogen ion concentration c. The negative logarithm of the relative hydroxyl ion concentration d. The positive logarithm of the relative hydroxyl ion concentration 2. How many buffers are recommended for proper calibration…
1. In a lift station with a diameter of 10 feet, you are able to lower the water level 6 inches in 2 minutes. What is the pumping rate in gallons per minute? 2. What is the pumping rate, in gallons per minute, if you are wasting sludge to a 20-ft diameter tank and the…
1. The pH scale ranges from a. 1 to 12 b. 2 to 12 c. 0 to 14 d. 2 to 14 2. Fresh pH buffers should be poured a. Daily b. Weekly c. Monthly d. Per manufacturer’s specifications 3. How often should a pH meter be calibrated to ensure accuracy a. Twice a day…
1. Characteristics that should be measured immediately after the sample is collected are _. a. Velocity and dissolved solids b. Temperature, pH and DO c. Sulfur, iron and copper d. Hardness and alkalinity 2. The best method for collecting residual chlorine samples is _. a. Grab samples during the day b. Composite samples made up…
1. Find pumping rate of lift station if gpm. Wet well diameter: 8 ft Drawdown time: 315 sec Refill time: 523 sec Drawdown distance: 2.26 ft Refill distance: 2.35 ft 2. Wet well diameter: 10 ft, Drawdown time: 5 min, 7 sec, Drawdown distance: 2 ft 4 inches, Refill time: 7 min, 23 sec, Refill…
1. Mixed liquor suspended solids: 3,000 mg/L, Aeration tank: 70 ft long, 42 feet wide, 10 feet deep Find pounds of solids contained in the aeration tank 2. Mixed liquor suspended solids: 5,000 mg/L, Aeration tank: 70 ft long, 42 ft wide, 10 ft deep Find pounds of solids under aeration 3. An activated sludge…
