Wastewater Operator certification Study Guide-Grade 2

Wastewater Operator certification Study Guide-Grade 2 General Wastewater Treatment: What is the pressure head caused by? Ans- Water elevation General Wastewater Treatment: What color should the piping be that contains reclaimed water? Ans- purple General Wastewater Treatment: What is the term for the height to which a column of water will rise in a well. Ans- piezometric surface General Wastewater Treatment: In general, what is the maximum practical lift of pumps Ans- 15-25ft General Wastewater Treatment: Which one of the following valves is the best to use in throttling a flow situation? a. gate b. butterfly c. globe d. ball Ans- globe General Wastewater Treatment: Which one of the following devices is used to measure water depths in storage facilities? a. transducer b. Venturi meter c. magnetic sensor d. thermistor Ans- transducer Wastewater Treatment Facilities: The velocity in sanitary sewers is approximately: Ans- 2 ft/s Wastewater Treatment Facilities: The distance between manholes ranges from Ans- 300-500ft Wastewater Treatment Facilities: What should the flow velocity be through a grit channel Ans- 1.0 ft/s Wastewater Treatment Facilities: Grit washers are used to______ a. remove some of the organic matter b. remove large pieces of wood c. remove rags and eggshells d. remove the odors Ans- remove some of the organic matter Wastewater Treatment Facilities: The most common flow-measure device for wastewater is a_____ Ans- parshall flume Wastewater Treatment Facilities: The detention time for primary clarifiers usually has a range of_____hr/s Ans- 1.5-2hr Wastewater Treatment Facilities: The effluent from which process is called mixed liquor dary clarification b. primary clarification c. sludge drying bed or pond d. activated sludge Ans- activated sludge Wastewater Treatment Facilities: Aerobic ponds usually range in depth from ___-____ft Ans- 3-6ft Wastewater Treatment Facilities: Anaerobic ponds usually range in depth from___-___ft Ans- 8-12ft Wastewater Treatment Facilities: Another name for a waste stabilization pond is Ans- raw wastewater lagoon Wastewater sources & characteristics: Typically what average percent of total solids in a domestic wastewater, both dissolved and suspended, are inorganics Ans- 50% Wastewater sources & characteristics: Typically, what average percent of total solids in domestic wastewater, both dissolved and suspended, are inorganics? Ans- 50% Wastewater sources & characteristics: Approx. what % of the dissolved solids in wastewater are inorganics Ans- 87% Wastewater sources & characteristics: Approximately what % of the dissolved solids in wastewater are organics Ans- 12% Wastewater sources & characteristics: Which organism wold most probably be associated with moderate sludge age and effluent water quality Ans- free-swimming ciliates Wastewater sources & characteristics: Which organism would most probably be associated with high suspended solids and biochemical oxygen demand (BOD) Ans- amoebas Wastewater sources & characteristics: High suspended solids and BOD are most probably associated with which type of organisms? Ansflagellates Wastewater sources & characteristics: What organism would most likely enhance the penetration of oxygen into the activated sludge Ansrotifers Rocks/Screens/Comminutors & Grit Removal: Chlorine gas has a specific gravity of Ans- 2.5 specific gravity Rocks/Screens/Comminutors & Grit Removal: Proper flow velocity through a grit channel is indicated when the grit being removed contains a. no organics b. a little organic material c. about half the volume as the grit being removed d. about the same volume as the grit being removed Ans- a little organic material Sedimentation and Flotation: Surface loading and detention time is a clarifier are directly related to: Ans- flow through a clarifier Sedimentation and Flotation: What is the expected range for the removal of settleable solids from a primary clarifier? Ans- 95-99% Sedimentation and Flotation: What condition will occur if sludge is not pumped out of primary clarifiers at regular intervals? Ansclarifier will become septic Sedimentation and Flotation: Secondary clarifiers are usually located after: a. primary clarifier b. an anaerobic digester c. a biological process d. preaeration Ans- a biological process Sedimentation and Flotation: Filter sloughings are a product of: Ans- biological action Sedimentation and Flotation: when one liquid is dissolved in another liquid it is called Ans- an emulsion Sedimentation and Flotation: What is the optimum temperature for digester substances? Ans- 90 degrees F Secondary Treatment: Which one of the following types of wastewater ponds listed below is not classified like the other three? a. polishing pond 2. oxidation pond c. aerobic pond d. raw sewage Ans- aerobic pond Secondary Treatment: What type of pond would receive wastewater form a secondary treatment system? Ans- polishing pond Secondary Treatment: The color of the bio-film on a rotating biological contactor undergoing nitrification would appear? Ansreddish brown to golden Secondary Treatment: The color of the bio-film on a rotating biological contactor that has high sulfur concentrations would appear Ans- chalky white Secondary Treatment: Rotating biological contactors have all the following advantages except: a. high sludge production b. they can handle a large range of flows c. power requirements are low d. low operating costs, as they are east to run Ans- high sludge production Secondary Treatment: A wastewater [plant has a train of three rotating biological contactor (RBC) units. The color of the first RBC is___; the color of the second RBC is_____; and the color of the third RBS C is____ Ans- (1) gray (2) reddish brown (3) reddish brown Activated Sludge: Following the activated sludge what process modification is very sensitive to bulking? a. conventional modification b. extended aeration activate sludge c. complex mix aeration d. pure oxygen Ans- conventional modification Activated Sludge: What modified activated sludge process does not require primary treatment? ete mix aeration b. contact stabilization c. tapered aeration d. step aeration Ans- contact stabilization Activated Sludge