1. Nitrification inhibition may begin when the alkalinity level drops below _ mg/L as CaCO3. a. 50 b. 60 c. 75 d. 100 2. The nitrification unit effluent COD shows a sudden increase. The probable cause is _. a. decrease in effluent BOD. b. Excessive addition of methanol c. lack of nitrate in effluent d….
1. If the chlorine chemical dose is 3 mg/L and the feed in lbs/day is 280, what is the flow in MGD? 2. A rectangular basin 12 feet long and 9 feet wide is 6 feet deep. It treats a flow of 90,000 gallons per day. Determine the detention time in hours. 3. Determine the…
1. In dissolved air floatation thickeners floated solids are kept out of the effluent by use of _. a. effluent baffles b. hardware cloth screens c. macroscreens d. scum scrapers e. water sprays 2. Cyrogenic oxygen plants are usually shut down _ for maintenance. a. once every six months b. once every year c. once…
1. Water in a pipe travels 210 feet every three minutes. What is the velocity in feet per minute? 2. Convert the answer in #1 to feet per second. 3. A pipe has a diameter of 1 foot and the velocity in that pipe is 2.5 ft/sec. What is the flow rate in cubic feet…
1.Determine the chlorine demand of an effluent it the chlorine dose is 10.0 mg/L and the chlorine residual is 1.1 mg/L. 2. To maintain satisfactory chlorine residual in a plant effluent, the chlorine dose must be 10 mg/L when the flow is 0.37 MGD. Determine the chlorinator setting, (feed rate) in lbs/day 3. Determine the…
1. What is a typical reduction in volume when dewatered sludge is incinerated? a. 20 – 30% b. 35 – 50% c. 55 – 79% d. 80 – 90% 2. What sludge does air floatation typically treat? a. primary b. waste activated c. digested anaerobic 3. Which pump is best for pumping chemicals? a. positive…
To calculate the different loadings on a pond, the information listed under known must be available. Keep in mind math is math – so work these problems even if you don’t have Ponds on your level exam. Good practice. Known Average Depth = 4 ft Average Width = 400 ft Average Length = 600 ft…
1. Following coagulation, the next step in physical-chemical treatment is called _. a. brownian b. destabilization c. flocculation d. precipitation 2. In order to get coagulation to proceed, a chemical change process must occur which is called _. a. brownian b. destabilization c. flocculation d. precipitation 3. The solubility of metals increases as pH _….
Lab results and flow rate for an activated sludge are listed below under the known column. Information helpful to the operator in controlling the process is listed in the unknown column. The aerator or aerator tank volume is 70600 cuft. Known Mixed Liquor Suspended Solids (MLSS) = 1,800 mg/L Mixed Liquor Volatile Content = 76%…
1. In dissolved air floatation thickeners floated solids are kept out of the effluent by use of _. a. effluent baffles b. hardware cloth screens c. macroacreens d. scum scrapers e. water sprays 2. Cryogenic oxygen plants are usually shut down _ for maintenance. a. once very six months b. once every year c. once…
