Operation of Wastewater Treatment Plants (Levels 1-2 Exam Prep) || Questions and 100% Verified Answers.

An Imhoff cone is used to measure________solids. A. suspended B. colloidal C. volatile D. settleable correct answers D. settleable (Operation of Wastewater Treatment Plants, Volume 1 by Kenneth D. Kerri) A _____ flume is widely used for measuring wastewater flow. correct answers Parshall (Operation of Wastewater Treatment Plants, Volume 1 by Kenneth D. Kerri) Velocity of flow in a grit channel must be reduced to a range of ____ to _____ fps in order for grit to properly settle. correct answers .7 to 1.4 fps (Operation of Wastewater Treatment Plants, Volume 1, 3.33 by Kenneth D. Kerri) With respect to grit removal systems, grit is traditionally defined as particles larger than 0.21mm (0.008 in) (65 mesh) and with a specific gravity of greater than ______. correct answers specific gravity of grit is 2.65 or greater (EPA Wastewater Technology Fact Sheet, Screening and Grit Removal) Mechanically cleaned bar screens feature bars set at _____ to _____ degrees from vertical. correct answers Bars set at 0 to 30 degrees from vertical. (EPA Wastewater Technology Fact Sheet, Screening and Grit Removal) Manually cleaned bar screens feature bars set at _____ to _____ degrees from vertical to facilitate cleaning. correct answers Bars set at 30 to 45 degrees from vertical to facilitate cleaning. Primarily used in older or smaller treatment facilities, or in bypass channels. (EPA Wastewater Technology Fact Sheet, Screening and Grit Removal) The BOD test measures the amount of oxygen that is consumed while a sample of wastewater is incubated in the dark at a temperature of _____ °C for _____ days (± _____ hours) correct answers The BOD test measures the amount of oxygen that is consumed while a sample of wastewater is incubated in the dark at a temperature of 20 °C for 5 days (± 3 hours)