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ABC Wastewater Level 3 - General
This solids treatment method first chemically conditions the solids and then later in the process "throws" the solids out of the water: A. vacuum filter B. belt filter and plate C. centrifuge D. solids concentrators - ✔ ✔ C. centrifuge This solids treatment method maximizes the reduction of moisture and solids: A. incineration B. centrifuge C. thermal treatment D. vacuum filter - ✔ ✔ A. incineration Which solids treatment method removes 100% of the pathogens, water, and organics? A. centrifuge B. chlorine oxidation C. thermal treatment D. incineration - ✔ ✔ D. incineration In general, secondary sludges
A. contain 20 to 25% nonvolatile inorganic matter B. are more fibrous C. have less flocculant than primary sludges D. have a density significantly greater than water - ✔ ✔ A. contain 20 to 25% nonvolatile inorganic matter Which type of centrifuge uses a knife or plow insertion to scrape off the cake from its walls? A. scroll centrifuge B. basket centrifuge C. pressure-cone centrifuge D. disc-nozzle centrifuge - ✔ ✔ B. basket centrifuge Which type of centrifuge uses an outer screw conveyor to move the solids to the discharge point? A. scroll centrifuge B. basket centrifuge C. pressure-cone centrifuge D. disc-nozzle centrifuge - ✔ ✔ A. scroll centrifuge What is the ideal temperature range for methane-forming bacteria in anaerobic digesters? A. 90 to 98° B. 92 to 102°
What type of protozoan is typically associated with a poor treatment process and a young biosolids age? A. sporozoans B. ciliates C. flagellates D. the Sarcondina - ✔ ✔ C. flagellates The most common pathogen identified in waterborne disease outbreaks in the United States is A. Cryptosporidium B. Giardia C. Entamoeba D. Cyclospora - ✔ ✔ B. Giardia The major gas produced by aerobic decomposition is A. nitrogen B. hydrogen sulfide C. carbon dioxide D. methane - ✔ ✔ C. carbon dioxide If an induction motor is rated at 40 amps for a full-load current, what will be the most probable starting sequences amps required? A. 60 to 80 amps B. 80 to 120 amps
C. 120 to 200 amps D. 200 to 320 amps - ✔ ✔ D. 200 to 320 amps Motor insulation material comes in four classes and they are based on A. temperature limitation B. thickness of insulation C. composition of insulation D. type of motor for which the insulation is being used - ✔ ✔ A. temperature limitation The current imbalance between legs of polyphase motors should never exceed A. 1% B. 2% C. 5% D. 10% - ✔ ✔ C. 5% The allowable voltage above or below the value stamped on a motor's nameplate is A. 1% B. 3% C. 5% D. 10% - ✔ ✔ D. 10%
B. self-contained breathing apparatus C. potassium tetraoxide canister type D. activated carbon canister type - ✔ ✔ B. self-contained breathing apparatus Which of the following types of fire extinguishers should be used on electrical fires? A. fire-resistant blanket B. sodium bicarbonate C. carbon dioxide D. soda-acid - ✔ ✔ C. carbon dioxide Which one of the following provides a profile of hazardous substances or mixtures? A. Occupational Safety and Health Administration (OSHA) B. Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) C. Code of Federal Regulations (CFR) D. material safety data sheet (MSDS) - ✔ ✔ D. material safety data sheet (MSDS) An atmosphere is defined as oxygen deficient if it contains less than what percent oxygen by volume? A. 16.5%
B. 18.5%
C. 19.5%
D. 19.8% - ✔ ✔ C. 19.5%
What class of fire involves sodium and magnesium? A. Class A B. Class B C. Class C D. Class D - ✔ ✔ D. Class D What is the proper emergency chlorine kit for a 1-ton chlorine cylinder? A. emergency kit A B. emergency kit B C. emergency kit C D. emergency kit T - ✔ ✔ B. emergency kit B The specific gravity standard for gases is A. water vapor at 100°C B. air C. oxygen D. nitrogen - ✔ ✔ B. air The standard for gases has a density of A. 1.00 g/L
A. O₂⁺³
B. NO₂
C. O₃
D. N₂O - ✔ ✔ C. O₃
Which laboratory glassware can be used to heat liquids in an open flame? A. flasks B. graduated cylinders C. volumetric flasks D. burettes - ✔ ✔ A. flasks When inserting glass tubing into rubber hose or stoppers, never use _______ for lubrication. A. oil B. flame polishing C. water D. lubricating jelly - ✔ ✔ A. oil Electrical units operating in areas exposed to flammable vapors should A. be removed and reinstalled in a separate room B. be housed in a tightly sealed container C. be double-insulated
D. be explosion-proof - ✔ ✔ D. be explosion-proof Usually, what is the percent accuracy of a graduated cylinder ad burette? A. 1% B. 1.5% C. 0.5 and 1%, respectively D. 1% and 0.5%, respectively - ✔ ✔ A. 1% The clarity of a trickling filter's effluent is considered good when the Secchi disk can read at a level of A. 1 ft B. 2 ft C. 3 ft D. 4 ft - ✔ ✔ C. 3 ft The clarity of the effluent from an activated sludge process is considered good when the Secchi disk can be read at a level of A. 3 ft B. 4 ft C. 5 ft D. 6 ft - ✔ ✔ D. 6 ft Sodium chloride is used in the low pressure wet oxidation unit's A. water softener
DATA: Blower air rate output high Organic load normal Hydraulic load normal Borderline low dissolved oxygen Low turbulence throughout aeration tank A. aeration system piping leaking B. excessive air bubble shearing by diffusers C. return sludge rate too high D. underaeration because of low blower speed - ✔ ✔ A. aeration system piping leaking Given the data below, what is the most likely cause of the extended aeration facility problem? DATA: Blower normal Flow normal for dry weather DO level normal Drop pipe air control valves half open Dead spot on surface around one drop pipe Dead spot remains when drop pipe air control valve fully open A. air header pipe clogged B. blower discharge pipe clogged
C. blower intake filter clogged D. drop pipe clogged - ✔ ✔ D. drop pipe clogged An incubator for the BOD test should be controlled at ______ C. A. 15 B. 20 C. 25 D. 30 - ✔ ✔ B. 20 Results of the settleable solids test run using Imhoff cones may be used to A. calculate the Imhoff Settling Index (ISI) B. calculate the pounds of solids pumped to the digester C. indicate the quality of the final effluent D. none of the above - ✔ ✔ B. calculate the pounds of solids pumped to the digester In certain situations, a supervisor encourages the employees to make their own decisions. This is considered to be A. against the rules to follow past experiences in decision-making B. bad form since the supervisor eventually loses control C. highly desirable, since it encourages employee growth and frees the D. supervisor for other tasks
C. decentralized D. unstructured - ✔ ✔ C. decentralized Recognition and job security are indications of A. a good organization B. a good supervisor C. external morale factors D. internal morale factors - ✔ ✔ A. a good organization Generally, as an individual progresses upward in management, reliance on personal technical skill A. changes to the more complex B. decreases C. increases D. remains the same - ✔ ✔ B. decreases What equipment should be calibrated in a treatment plant? A. chemical feeders B. continuous recording chlorine residual analyzer C. continuous recording pressure gauges D. all of the above - ✔ ✔ D. all of the above Special parts that should be carried by the maintenance worker are usually listed in the
A. machine blue print B. machine history record C. machine manufacturer's manual D. work order - ✔ ✔ C. machine manufacturer's manual To protect a wastewater facility against vandalism, you should not use A. combination padlocks on the gates B. fencing around the entire facility C. metal doors D. windows that have plastic panes instead of glass - ✔ ✔ A. combination padlocks on the gates How can the supervisor be certain that scheduled maintenance is completed? A. ask the workers B. hire someone to inspect completed work C. use a form that compares work assigned with work completed D. wait and see if there are any failures - ✔ ✔ C. use a form that compares work assigned with work completed Word has just come down from the top that operating funds are being cut. How should this be handled? A. cut the supplies and repairs in order to balance the budget B. fire some of the less-productive old employees
E. tell the employee to shut up and work or quit and go home - ✔ ✔ A. explain that all employees must do their fair share of the hard work as well Occasionally some of the people on a work crew will indulge in active horseplay. This should be A. discouraged because some of the workers might not like it B. encourage because it promotes good fellowship C. permitted as it is a form of relaxation D. stopped immediately because it is likely to cause an accident - ✔ ✔ D. stopped immediately because it is likely to cause an accident The temperature versus DO relationship for wastewater is such that the A. higher the temperature, the higher the DO saturation level B. higher the temperature, the lower the DO saturation level C. lower the temperature, the lower the DO saturation level D. none of the above - ✔ ✔ B. higher the temperature, the lower the DO saturation level The gas most commonly associated with fresh wastewater is A. carbon dioxide B. carbon monoxide C. hydrogen sulfide D. oxygen - ✔ ✔ D. oxygen
"Hz" stands for A. cycles per second B. hand control C. horizontal phase D. polyphase - ✔ ✔ A. cycles per second Anaerobic wastewater is frequently corrosive to materials it contacts, especially A. coal tar enamel B. concrete C. copper D. plastic - ✔ ✔ B. concrete The electrical disconnect for a pumping station motor can trip out under which one(s) of the following possibilities? A. clogged pump inlet B. low temperature C. strike by lightning D. worn packing - ✔ ✔ C. strike by lightning One of the electric motors in the facility has overheated and caught fire. Select the correct sequence of steps you would take.
- extinguish fire
- test
