{"id":110433,"date":"2023-07-26T19:31:24","date_gmt":"2023-07-26T19:31:24","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=110433"},"modified":"2023-07-26T19:31:28","modified_gmt":"2023-07-26T19:31:28","slug":"wastewater-treatment-operator-certification-test-2023-questions-and-answers-verified-answers","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2023\/07\/26\/wastewater-treatment-operator-certification-test-2023-questions-and-answers-verified-answers\/","title":{"rendered":"Wastewater Treatment Operator Certification Test 2023 Questions and Answers (Verified Answers)"},"content":{"rendered":"\n<p>What is the methane content in a properly operation anaerobic digester?<\/p>\n\n\n\n<p>A) 30 to 35% by volume<br>B) 1 to 2% by volume<br>C) 65 to 70% by volume<br>D) 15 to 20% by volume<br>C) 65 to 70% by volume (v.2 pg 158)<\/p>\n\n\n\n<p>What will the addition of chlorine gas do to the pH of wastewater?<\/p>\n\n\n\n<p>A) Moderately increase pH<br>B) pH will not be affected<br>C) Significantly increase the pH<br>D) Decrease the pH<br>D) Decrease the pH (v.1 pg 349-350)<\/p>\n\n\n\n<p>What is the purpose of a Parshall flume?<\/p>\n\n\n\n<p>A) measure turbidity<br>B) measure flowrate<br>C) measure settling rate<br>D) measure solids content<br>B) measure flowrate (v.1 pg 43)<\/p>\n\n\n\n<p>What is the typical removal efficiency of settable solids in a primary clarifier?<\/p>\n\n\n\n<p>A) 95 to 99%<br>B) 40 to 60%<br>C) 20 to 50%<br>D) 10 to 15%<br>A) 95 to 99% (v.1 pg 129)<\/p>\n\n\n\n<p>Which of the following is true about pumping scum from a primary clarifier?<\/p>\n\n\n\n<p>A) Pumping scum is less problematic during colder weather.<br>B) Scum rarely leads to plugged pipelines due to its viscous nature.<br>C) Scum causes more piping problems than other substances pumped at a wastewater treatment plant.<br>D) Scum causes the least amount of piping problems among all the substances pumped at a wastewater treatment plant.<br>C) Scum causes more piping problems than other substances pumped at a wastewater treatment plant. (v.2 pg 449)<\/p>\n\n\n\n<p>What might cause thick billows of white sudsy foam in the aeration tank?<\/p>\n\n\n\n<p>A) MLSS is too high<br>B) Temperature in the aeration tank is too low<br>C) Old sludge<br>D) MLSS is too low<br>D) MLSS is too low (v.2 pg 53,75)<\/p>\n\n\n\n<p>What does the &#8220;M&#8221; in F\/M ratio represent?<\/p>\n\n\n\n<p>A) MLSS in aeration tank<br>B) The influent BOD loading rate into the aeration tank<br>C) The mixed liquor volatile suspended solids in the aeration tank<br>D) The mass of inorganic solids in the aeration tank<br>C) The mixed liquor volatile suspended solids in the aeration tank (v.2 pg 16)<\/p>\n\n\n\n<p>In general, how will warmer temperature affect the settling rate of solids in a clarifier?<\/p>\n\n\n\n<p>A) Decrease settling rate<br>B) Increase the settling rate<br>C) Temperature will not affect the settling rate<br>D) Worsen the settling rate<br>B) Increase the settling rate (v.1 pg 134)<\/p>\n\n\n\n<p>What could happen if the digester gas is mixed with air (85 to 95% by volume)?<\/p>\n\n\n\n<p>A) Cause an explosion<br>B) Improve efficiency of digestion<br>C) The bacteria will become aerobic and increase VSR<br>D) The digester becomes safer to operate due to less toxic gas in the system<br>A) Cause an explosion (v.2 pg 158)<\/p>\n\n\n\n<p>How will algae impact the chlorine demand in the pond effluent?<\/p>\n\n\n\n<p>A) Slightly decreases chlorine demand<br>B) Does not affect chlorine demand<br>C) Significantly decreases chlorine demand<br>D) Increases chlorine demand<br>D) Increases chlorine demand<\/p>\n\n\n\n<p>Which of the following is true about positive displacement pumps?<\/p>\n\n\n\n<p>A) It is a type of centrifugal pump<br>B) Suction valve should be closed when the pump is started<br>C) It must never be started with the discharge valve closed<br>D) Adds head to liquid using several impellers<br>C) It must never be started with the discharge valve closed (v.2 pg 435)<\/p>\n\n\n\n<p>What is true about the F\/M ratio?<\/p>\n\n\n\n<p>A) MLVSS data in not required to determine the F\/M ration<br>B) Volume of the secondary clarifier is not needed to determine the F\/M ratio<br>C) The amount of COD or BOD entering the aeration tank does not have to be known to calculate the F\/M ratio.<br>D) The amount of organisms in the aeration tank is not needed to calculate the F\/M ratio<br>B) Volume of the secondary clarifier is not needed to determine the F\/M ratio (v.2 pg 58)<\/p>\n\n\n\n<p>Which of the following is one of the basic rules of laboratory work?<\/p>\n\n\n\n<p>A) Do not leave keys in equipment or vehicles at any time<br>B) Patrol the facilities frequently, and look for suspicious activity or behavior<br>C) never pipet hazardous material with your mouth, even if the pipet has be sterilized<br>D) Lock out and tag out relevant mechanical and electrical equipment before starting any maintenance activity.<br>C) never pipet hazardous material with your mouth, even if the pipet has be sterilized (v.2 pg 493)<\/p>\n\n\n\n<p>What is the recirculation ratio for a trickling filter?<\/p>\n\n\n\n<p>A) Q_r\/Q<br>B) Q\/Q_r<br>C) Q\/Q_r+Q<br>D) Q_r+Q\/Q<br>A) Q_r\/Q<\/p>\n\n\n\n<p>Which of the following is true about COD and BOD?<\/p>\n\n\n\n<p>A) They are direct measurements of organic content in the influent<br>B) They measure the inorganic content of the influent<br>C) They represent the amount of filamentous bacteria in the influent<br>D) They are indirect measurements of the organic content in the influent<br>D) They are indirect measurements of the organic content in the influent<\/p>\n\n\n\n<p>What is the purpose of the grit channel?<\/p>\n\n\n\n<p>A) Remove dissolved and non-settleable organics<br>B) Remove heavy inorganic wastes<br>C) To allow activated sludge to settle<br>D) Remove substances that float and readily settle from the wastewater as part of primary treatment<br>B) Remove heavy inorganic wastes (v.1 pg 84)<\/p>\n\n\n\n<p>Which of the following is true about the extended aeration process?<\/p>\n\n\n\n<p>A) Bugs get more food<br>B) Wasting is not necessary<br>C) It does not produce as much waste sludge as the other processes<br>D) It is very different from the conventional activated sludge process<br>C) It does not produce as much waste sludge as the other processes (v.1 pg 257)<\/p>\n\n\n\n<p>What is the correct formula for solids in raw wastewater?<\/p>\n\n\n\n<p>A) Non-volatile solids + Suspended solids= Total solids in the influent<br>B) Dissolved solids + Settable solids= Total suspended solids<br>C) Colloids + Dissolved solids = Total suspended solids<br>D) Non-settleable solids + Settable solids= Total suspended solids.<br>D) Non-settleable solids + Settable solids= Total suspended solids (v.1 pg 22)<\/p>\n\n\n\n<p>What is the &#8220;freeboard&#8221; in a waste stabilization pond?<\/p>\n\n\n\n<p>A) Operational depth of the pond<br>B) Wooden inlet and outlet structures<br>C) Wooden baffles<br>D) Vertical distance from normal water surface to the top of the levee<br>D) Vertical distance from normal water surface to the top of the levee (v.1 pg 519)<\/p>\n\n\n\n<p>What is one of the requirements for a BOD test?<\/p>\n\n\n\n<p>A) The BOD bottle should be completely filled to the top<br>B) The BOD bottles must be 100 ml in size<br>C) Samples should be incubated at 30 degrees Celsius<br>D) Stoppers should not be installed on the bottles to ensure proper air flow to the samples<br>A) The BOD bottle should be completely filled to the top (v.2 pg 574)<\/p>\n\n\n\n<p>What should be scheduled every 3 months for a flamer arrester in an anaerobic digester?<\/p>\n\n\n\n<p>A) Replacement<br>B) Maintenance<br>C) Flow Test<br>D) Temperature Test<br>C) Flow Test (v.2 pg 162)<\/p>\n\n\n\n<p>What is common practice in an activated sludge process?<\/p>\n\n\n\n<p>A) Waste all activated sludge<br>B) Sludge age of 14 days for conventional system<br>C) Recirculate activated sludge (RAS)<br>D) Limiting DO to increase the mircoorganism population<br>C) Recirculate activated sludge (RAS) (v.2 pg 20,21)<\/p>\n\n\n\n<p>Prior to entering a permit required confined space, what should you verify?<\/p>\n\n\n\n<p>A) a standby person should be at the entrance to the confined space. An additional person is not required<br>B) A standby person should be within 30 feet of the confined space.<br>C) A standby person should be within 50 feet of the confined space.<br>D) A standby person should be located outside the entrance to the confined space, while another person should be within sight or call of the standby person.<br>D) A standby person should be located outside the entrance to the confined space, while another person should be within sight or call of the standby person. (v.2 pg 270)<\/p>\n\n\n\n<p>What is a common way to determine the organic strength of wastes in the influent?<\/p>\n\n\n\n<p>A) Test for the biochemical oxygen demand<br>B) Test for the biological oxygen demand<br>C) Test for the volatile solids reduction<br>D) Test for the carbon and hydrogen concentrations<br>A) Test for the biochemical oxygen demand (v.1 pg 505)<\/p>\n\n\n\n<p>What should you do if you are mildly exposed to chlorine gas?<\/p>\n\n\n\n<p>A) Breathe heavily to inhale clean air<br>B) Cough to release chlorine from lungs<br>C) Immediately evacuate the contaminated area, remain calm, keep warm, breathe lightly, and avoid coughing<br>D) Keep your body as cool as possible<br>C) Immediately evacuate the contaminated area, remain calm, keep warm, breathe lightly, and avoid coughing (v.1 pg 377)<\/p>\n\n\n\n<p>What are the main sources of domestic sewage in the collection system?<\/p>\n\n\n\n<p>A) Canals<br>B) Surface flow<br>C) Ocean outfall<br>D) Households and commercial establishments<br>D) Households and commercial establishments (v.1 pg 33)<\/p>\n\n\n\n<p>Why is it important to maintain a horizontal weir in a clarifier?<\/p>\n\n\n\n<p>A) Prevent sludge bulking<br>B) Prevent short circuiting<br>C) Prevent gasification<br>D) Prevent excessive slime growth<br>B) Prevent short circuiting (v.1 pg 131)<\/p>\n\n\n\n<p>What are mostly removed in the grit channel?<\/p>\n\n\n\n<p>A) Biomass<br>B) Organics<br>C) Dissolved solids<br>D) Sand, eggshells, cinders, and heavier particulate matter<br>D) Sand, eggshells, cinders, and heavier particulate matter (v.1 pg 84)<\/p>\n\n\n\n<p>How often should an anaerobic digester be fed?<\/p>\n\n\n\n<p>A) Several times a day<br>B) Once a day<br>C) Twice a week<br>D) Five times per week<br>A) Several times a day (v.2 pg 185)<\/p>\n\n\n\n<p>What is the health effect of carbon dioxide?<\/p>\n\n\n\n<p>A) Vomiting<br>B) Migraine<br>C) Can lead to asphyxiation<br>D) Rapid heart beat<br>C) Can lead to asphyxiation (v.2 pg 268)<\/p>\n\n\n\n<p>Which of the following enters the headworks of a treatment plant?<\/p>\n\n\n\n<p>A) Effluent<br>B) Supernatant<br>C) WAS<br>D) Influent<br>D) Influent (v.1 pg 33)<\/p>\n\n\n\n<p>Which gas diminishes your sense of smell?<\/p>\n\n\n\n<p>A) Hydrogen<br>B) Hydrogen Sulfide<br>C) Nitrogen<br>D) Ethane<br>B) Hydrogen Sulfide (H_2S) (v.2 pg 268)<\/p>\n\n\n\n<p>What type of microorganisms can use nitrate as a source of oxygen?<\/p>\n\n\n\n<p>A) Aerobic bacteria<br>B) Anaerobic bacteria<br>C) Facultative bacteria<br>D) Zoogleal<br>C) Facultative bacteria (v.1 pg 254)<\/p>\n\n\n\n<p>What is the equivalent of 1 mg\/L<\/p>\n\n\n\n<p>A) 1 ppb<br>B) 10 ppm<br>C) 10 ppb<br>D) 1 ppm<br>D) 1 ppm (v.1 pg 468)<\/p>\n\n\n\n<p>Select the most accurate statement about extended aeration.<\/p>\n\n\n\n<p>A) The bugs are retained in the aeration tank much shorter than the conventional activated sludge system.<br>B) Extended aeration produces the most waste sludge compared to other sludge processes<br>C) An oxidation ditch is usually operated in extended aeration mode, and is used for small flows<br>D) Extended aeration is the least common type of package plant treatment process<br>C) An oxidation ditch is usually operated in extended aeration mode, and is used for small flows (v.1 pg 269)<\/p>\n\n\n\n<p>What is equivalent to organic solids?<\/p>\n\n\n\n<p>A) Volatile Solids<br>B) Fixed Solids<br>C) Suspended Solids<br>D) Colloids<br>A) Volatile Solids (v.1 pg 546)<\/p>\n\n\n\n<p>What should be done if a large amount of organic matter is found in the grit channel?<\/p>\n\n\n\n<p>A) Decrease the velocity of the wastewater<br>B) Inject sodium hydroxide at the headworks<br>C) Raise the pH<br>D) Increase the velocity of the wastewater<br>D) Increase the velocity of the wastewater (v.1 pg 87)<\/p>\n\n\n\n<p>Which flowrate should you use to calculate the hydraulic loading to a trickling filter?<\/p>\n\n\n\n<p>A) Plant inflow<br>B) Plant inflow minus recirculated flow<br>C) Plant inflow plus recirculated flow<br>D) Recirculated flow<br>C) Plant inflow plus recirculated flow (v.1 pg 199)<\/p>\n\n\n\n<p>What is the difference between the sludge from a primary clarifier and secondary clarifier?<\/p>\n\n\n\n<p>A) Secondary sludge is denser than primary sludge<br>B) Primary sludge is denser than secondary sludge<br>C) Specific gravity of secondary sludge is larger than that of a primary sludge<br>D) Primary sludge has a smaller specific weight than secondary sludge<br>B) Primary sludge is denser than secondary sludge (v.1 pg 109)<\/p>\n\n\n\n<p>Which process includes a blower?<\/p>\n\n\n\n<p>A) Trickling filter<br>B) Waste stabilization pond<br>C) Chlorine contact tank<br>D) Activated sludge<br>D) Activated sludge (v.2 pg 28)<\/p>\n\n\n\n<p>How does an activated sludge system remove waste from wastewater?<\/p>\n\n\n\n<p>A) Physical Treatment<br>B) Chemical Treatment<br>C) Biological Treatment<br>D) Radiological Treatment<br>C) Biological Treatment (v.2 pg 16)<\/p>\n\n\n\n<p>Which of the following best describes pre-chlorination?<\/p>\n\n\n\n<p>A) Mainly used for disinfection and requires a large amount of chlorine residual in the wastewater at the chlorine contact chamber.<br>B) Addition of chlorine to wastewater a the entrance to the plant, and used for odor control, BOD reduction, grease removal, and aid sedimentation<br>C) Injection on a well-clarified effluent<br>D) Describes a type of chlorination to address sludge bulking<br>B) Addition of chlorine to wastewater a the entrance to the plant, and used for odor control, BOD reduction, grease removal, and aid sedimentation (v.1 pg 354)<\/p>\n\n\n\n<p>When would you expect reduced algae population and less oxygen released into a pond?<\/p>\n\n\n\n<p>A) Fall and winter, when the weather is cool and sunlight is reduced<br>B) Summer, when there is abundant sunlight<br>C) Spring, when the weather transitions from cool to warm<br>D) When photosynthesis is very effective and at its peak<br>A) Fall and winter, when the weather is cool and sunlight is reduced (v.1 pg 309)<\/p>\n\n\n\n<p>What is the first step of the lockout\/tagout procedure?<\/p>\n\n\n\n<p>A) Shut down the equipment if it is operating<br>B) Operate the energy isolating device so that the equipment is isolated form its energy source<br>C) Lockout the equipment with assigned lock or tag<br>D) Notify all affected employees that a lockout or tagged system is going to be used and the reason why.<br>D) Notify all affected employees that a lockout or tagged system is going to be used and the reason why (v.2 pg 274)<\/p>\n\n\n\n<p>What type of process is the activated sludge system?<\/p>\n\n\n\n<p>A) Anaerobic<br>B) Anoxic<br>C) Aerobic<br>D) Ionic<br>C) Aerobic (v.1 pg 46)<\/p>\n\n\n\n<p>What will happen if too much raw sludge is added to the digester?<\/p>\n\n\n\n<p>A) pH will increase due to the increase in sodium hydroxide<br>B) Acid fermenters will predominate and lower the pH<br>C) pH will not be affected<br>D) Methane fermenters will thrive<br>B) Acid fermenters will predominate and lower the pH (v.2 pg 184)<\/p>\n\n\n\n<p>What might cause sludge to rise in a clarifier?<\/p>\n\n\n\n<p>A) Gasification from aging sludge<br>B) pH is too high<br>C) Sludge withdrawal rate is too high<br>D) Photosynthesis<br>A) Gasification from aging sludge (v.1 pg 129)<\/p>\n\n\n\n<p>What happens when carbon dioxide is removed from a pond?<\/p>\n\n\n\n<p>A) Decreased pH<br>B) pH is not affected<br>C) Increased pH<br>D) Sudden increase in H_2S<br>C) Increased pH (v.1 pg 299)<\/p>\n\n\n\n<p>How much dissolved oxygen should be in a conventional activated sludge system if good effluent is being produced?<\/p>\n\n\n\n<p>A) 6 to 8 mg\/l<br>B) 0.5 to 1 mg\/l<br>C) 4 to 6 mg\/l<br>D) 2 to 4 mg\/l<br>D) 2 to 4 mg\/l (v.2 pg 53)<\/p>\n\n\n\n<p>What is the typical concentration of mixed liquor suspended solids in a conventional activated sludge process?<\/p>\n\n\n\n<p>A) 50 to 1,000 mg\/l<br>B) 1,000 to 4,500 mg\/l<br>C) 4,500 to 5,500 mg\/l<br>D) 5,500 to 6500 mg\/l<br>B) 1,000 to 4,500 mg\/l (v.2 pg 54)<\/p>\n\n\n\n<p>The temperature of the plant influent is<\/p>\n\n\n\n<p>A) Slightly warmer than tap water<br>B) Slightly colder than tap water<br>C) Much cooler than tap water<br>D) Much warmer than tap water<br>A) Slightly warmer than tap water<\/p>\n\n\n\n<p>The purpose of disinfection is to<\/p>\n\n\n\n<p>A) kill all microorganisms in the wastewater<br>B) Stabilize the pH<br>C) Destruction or inactivation of pathogenic bacteria<br>D) Oxidize the minerals in the effluent<br>C) Destruction or inactivation of pathogenic bacteria (v.1 pg 353)<\/p>\n\n\n\n<p>What must you do before entering a room with harmful concentration of chlorine gas in the air?<\/p>\n\n\n\n<p>A) Read the O&amp;M manual<br>B) Wear self-contained breathing apparatus (SCBA)<br>C) Prepare the fire extinguishers<br>D) Cover your mouth and spray aqueous ammonia in the room.<br>B) Wear self-contained breathing apparatus (SCBA) (v.1 pg 375)<\/p>\n\n\n\n<p>What does black sludge at the bottom of a secondary clarifier located downstream of a trickling filter signify?<\/p>\n\n\n\n<p>A) Pumping rate is excessive<br>B) Pumping duration is too long<br>C) Detention time is too short<br>D) Sludge has stayed in the secondary clarifier too long<br>D) Sludge has stayed in the secondary clarifier too long (v.1 pg 138)<\/p>\n\n\n\n<p>If the lab results show that the plant influent sample has a COD of 100 mg\/l and the BOD of 300 mg\/l, which of the following is most likely true?<\/p>\n\n\n\n<p>A) Lab results appear incorrect<br>B) Carbon concentration is very high<br>C) Organic content is unusually high<br>D) COD seems excessive<br>A) Lab results appear incorrect (v.2 pg 541)<\/p>\n\n\n\n<p>If a primary clarifier is placed out of service, then how should a plant with at least two trickling filters operate the system?<\/p>\n\n\n\n<p>A) Operate the filters in parallel<br>B) Divert the influent to several trickling filters<br>C) Operate the filters in series<br>D) Maintain existing operation without changing filter arrangement<br>C) Operate the filters in series (v.1 pg 191)<\/p>\n\n\n\n<p>What is the main reason for preventing a direct connection between potable water pipe and a stuffing box (packings) of a wastewater pump?<\/p>\n\n\n\n<p>A) Wears out the glands quicker<br>B) Glands should not be wet<br>C) Potable water will rapidly destroy the stuffing box<br>D) Cross Connection<br>D) Cross Connection (v.2 pg 414)<\/p>\n\n\n\n<p>Which of the following is true about algae in a pond?<\/p>\n\n\n\n<p>A) During the daytime, the algae will release carbon dioxide<br>B) During the daytime, the algae will release oxygen for the aerobic bacteria<br>C) Algae uses sunlight to produce hydrogen sulfide<br>D) Photosynthesis helps algae create carbon monoxide<br>B) During the daytime, the algae will release oxygen for the aerobic bacteria (v.1 pg 299)<\/p>\n\n\n\n<p>Which of the following is not true about hydrogen sulfide?<\/p>\n\n\n\n<p>A) Hydrogen sulfide is flammable<br>B) Hydrogen sulfide is explosive under certain conditions<br>C) Hydrogen sulfide is lighter than air<br>D) Hydrogen sulfide is toxic<br>C) Hydrogen sulfide is lighter than air (v.2 pg 268,505)<\/p>\n\n\n\n<p>What type of treatment if primarily used to thicken sludge instead of dewater the sludge?<\/p>\n\n\n\n<p>A) DAF<br>B) Sludge drying bed<br>C) Centrifuge<br>D) Vacuum filters<br>A) DAF (v.2 pg 219-227)<\/p>\n\n\n\n<p>Why should sludge at the bottom of a clarifier be removed in a timely manner?<\/p>\n\n\n\n<p>A) To improve the performance of the grit channel<br>B) To maintain a consistent volume of sludge in the drying bed<br>C) To minimize the formation of Chloramines<br>D) To prevent sludge gasification, which causes the sludge to float<br>D) To prevent sludge gasification, which causes the sludge to float (v.1 pg 130)<\/p>\n\n\n\n<p>What is the purpose of sludge digestion?<\/p>\n\n\n\n<p>A) Convert primary and secondary sludge to mostly hydrogen sulfide<br>B) Increase efficiency of the DAF<br>C) Reduce the volume of the sludge and stabilize the solids<br>D) increase solids volume<br>C) Reduce the volume of the sludge and stabilize the solids (v.2 pg 148)<\/p>\n\n\n\n<p>Which of the following is true about trickling filters?<\/p>\n\n\n\n<p>A) It is mostly an anaerobic process<br>B) The three main parts of a trickling filter are media, distribution system, and underdrain<br>C) In computing BOD loading, it is standard practice to include the BOD of the re-circulated effluent<br>D) Filter ponding is usually due to inadequate organic loading<br>B) The three main parts of a trickling filter are media, distribution system, and underdrain (v.1 pg 169)<\/p>\n\n\n\n<p>Which of the following could cause foaming in an anaerobic digester?<\/p>\n\n\n\n<p>A) Temperature is kept constant<br>B) Feeding sludge at a regular, short interval<br>C) Digester is well-mixed<br>D) Organic overload<br>D) Organic overload (v.2 pg 187,207)<\/p>\n\n\n\n<p>Which of the following parameters should be monitored several times a week in a pond?<\/p>\n\n\n\n<p>A) TDS<br>B) MLSS<br>C) Dissolved oxygen, temperature, and pH<br>D) MLVSS<br>C) Dissolved oxygen, temperature, and pH (v.1 pg 315)<\/p>\n\n\n\n<p>Which is true about the temperature in an anaerobic digester?<\/p>\n\n\n\n<p>A) Temperature in a digester should not be changed by more than 1 degree Fahrenheit per day.<br>B) Temperature must be changed significantly according to the sludge loading rate.<br>C) Temperature at the bottom should be higher than at the top of the digester.<br>D) Mesophilic digestion required a temperature between 105 to 108 degrees Fahrenheit.<br>A) Temperature in a digester should not be changed by more than 1 degree Fahrenheit per day (v.2 pg 191)<\/p>\n\n\n\n<p>The effectiveness of disinfection is determined by:<\/p>\n\n\n\n<p>A) The Chlorine residual concentration<br>B) The Chlorine demand<br>C) The Chloramine concentration in the effluent<br>D) The coliform concentration in the effluent<br>D) The coliform concentration in the effluent (v.1 pg 353)<\/p>\n\n\n\n<p>An increase in the acid\/alkalinity ratio for an anaerobic digester means<\/p>\n\n\n\n<p>A) The digester is in an ideal condition<br>B) The carbon dioxide content is decreasing<br>C) Acid concentration is increasing or alkalinity is decreasing<br>D) pH of the sludge in the digester is increasing<br>C) Acid concentration is increasing or alkalinity is decreasing (v.2 pg 191)<\/p>\n\n\n\n<p>Which of the following will not cause short circuiting in a clarifier?<\/p>\n\n\n\n<p>A) Uneven weir settings<br>B) Flow line of launder is low<br>C) Damaged or missing inlet baffles<br>D) Velocity of wastewater is greater in some sections than in others<br>B) Flow line of launder is low (v.1 pg 125,135)<\/p>\n\n\n\n<p>A grab sample is most suited for these constituents<\/p>\n\n\n\n<p>A) BOD<br>B) TSS<br>C) Suspended Solids Concentration<br>D) Residual Chlorine<br>D) Residual Chlorine (v.2 pg 499)<\/p>\n\n\n\n<p>The organic loading to a trickling filter is expressed as<\/p>\n\n\n\n<p>A) lbs BOD\/day\/1000 cuft<br>B) lbs BOD\/day\/1000 sqft<br>C) lbs BOD\/day\/sqft<br>D) lbs BOD\/1000 gallon<br>A) lbs BOD\/day\/1000 cuft (v.1 pg 199)<\/p>\n\n\n\n<p>How often should the sludge at the bottom of a clarifier be pumped?<\/p>\n\n\n\n<p>A) Once a week<br>B) Bi-weekly<br>C) Frequently throughout the day<br>D) Once every three days<br>C) Frequently throughout the day (v.1 pg 130)<\/p>\n\n\n\n<p>Which of the following will not affect the settling characteristics in a clarifier?<\/p>\n\n\n\n<p>A) Temperature<br>B) Short Circuit<br>C) Detention Time<br>D) Depth of launder<br>D) Depth of launder (v.1 pg 134-135)<\/p>\n\n\n\n<p>The best way to evaluate the effluent TSS concentration from a plant is to<\/p>\n\n\n\n<p>A) Check the grab sample at peak flow<br>B) Check the composite sample of TSS<br>C) Check the grab sample at low flow<br>D) Check the grab sample during average flow<br>B) Check the composite sample of TSS (v.1 pg 128)<\/p>\n\n\n\n<p>Which of the following is not associated with an aeration tank?<\/p>\n\n\n\n<p>A) RAS<br>B) WAS<br>C) RBC<br>D) MCRT<br>C) RBC (v.2 pg 56,59)<\/p>\n\n\n\n<p>What creates hydrogen sulfide?<\/p>\n\n\n\n<p>A) Excessive aeration<br>B) Surface active agents<br>C) Organic matter under aerobic condition<br>D) Decomposing organic matter under anaerobic condition<br>D) Decomposing organic matter under anaerobic condition (v.2 pg 299)<\/p>\n\n\n\n<p>A pond with a detention time of less than three days will perform similar to<\/p>\n\n\n\n<p>A) Sedimentation tank<br>B) Aeration tank<br>C) Trickling Filter<br>D) RBC<br>A) Sedimentation tank (v.1 pg 299)<\/p>\n\n\n\n<p>Which type of Bacteria is used for a Trickling Filter?<\/p>\n\n\n\n<p>A) Anaerobic bacteria<br>B) Anoxic bacteria<br>C) Aerobic bacteria<br>D) Facultative bacteria<br>C) Aerobic bacteria (v.1 pg 46)<\/p>\n\n\n\n<p>Which of the following is not associated with a trickling filter?<\/p>\n\n\n\n<p>A) Media<br>B) Filamentous bacteria<br>C) Zoogleal Film<br>D) Recirculation<br>B) Filamentous bacteria (v.1 pg 169)<\/p>\n\n\n\n<p>What is an MCRT?<\/p>\n\n\n\n<p>A) A calculation that indicates the tendency of activated sludge solids to thicken<br>B) A measure of food provided to bacteria in an aeration tank.<br>C) The amount of volatile suspended solids in the mixed liquor of an aeration tank<br>D) An expression of the average time a microorganism will spend in an activated sludge process.<br>D) An expression of the average time a microorganism will spend in an activated sludge process. (v.2 pg 59)<\/p>\n\n\n\n<p>What is the typical BOD removal efficiency in a primary clarifier?<\/p>\n\n\n\n<p>A) 10 to 15%<br>B) 40 to 60%<br>C) 20 to 50%<br>D) 95 to 99%<br>C) 20 to 50% (v.1 pg 129)<\/p>\n\n\n\n<p>What does the &#8220;F&#8221; in F\/M ratio represent?<\/p>\n\n\n\n<p>A) The microorganism population in the aeration tank<br>B) The amount of filamentous bacteria in the activated sludge process<br>C) The MLVSS in the aeration tank<br>D) The food for the microorganisms flowing into the aeration tank, in lbs\/day<br>D) The food for the microorganisms flowing into the aeration tank, in lbs\/day (v.2 pg 58)<\/p>\n\n\n\n<p>Which of the following describes the appearance of healthy activated sludge?<\/p>\n\n\n\n<p>A) Thick, greasy, dark tan foam<br>B) Brown with a moderate amount of crisp, white foam<br>C) Clear liquid with clear foam<br>D) Gray liquid with no foam<br>B) Brown with a moderate amount of crisp, white foam<\/p>\n\n\n\n<p>What is used to control filamentous organisms?<\/p>\n\n\n\n<p>A) Polymer<br>B) Sulfur Dioxide<br>C) Coagulant<br>D) Chlorine<br>D) Chlorine (v.1 pg 399)<\/p>\n\n\n\n<p>What are commonly used to control chlorine feed rate for disinfection?<\/p>\n\n\n\n<p>A) BOD and MLVSS<br>B) pH and temperature<br>C) Flow and chlorine residual<br>D) DO and TSS<br>C) Flow and chlorine residual (v.1 pg 356)<\/p>\n\n\n\n<p>Which toxic gas is commonly found in septic wastewater and smells like rotten eggs?<\/p>\n\n\n\n<p>A) Hydrogen Sulfide<br>B) Carbon monoxide<br>C) Hydrogen<br>D) Carbon Dioxide<br>A) Hydrogen Sulfide (v.2 pg 299)<\/p>\n\n\n\n<p>What is the permissible exposure limit for chlorine gas vapor during a normal 8 hour workday and a 40 hour work week?<\/p>\n\n\n\n<p>A) 0.1 ppm<br>B) 0.5 ppm<br>C) 1 ppm<br>D) 15 ppm<br>B) 0.5 ppm (v.2 pg 268)<\/p>\n\n\n\n<p>What is a vulnerability assessment?<\/p>\n\n\n\n<p>A) Assesses the impact of hydrogen sulfide to a concrete structure<br>B) Analyzes the impact of flow and infiltration problem to the plant hydraulics<br>C) Estimates the vulnerability of aquatic wildlife to excessive algae growth<br>D) Contingency planning to determine the vulnerability of the utility during various types of emergencies and identify corrective actions to reduce the risks<br>D) Contingency planning to determine the vulnerability of the utility during various types of emergencies and identify corrective actions to reduce the risks (v.2 pg 722)<\/p>\n\n\n\n<p>What is the difference between the settling rate of activated sludge and raw sludge?<\/p>\n\n\n\n<p>A) Activated sludge settles slightly faster than raw sludge<br>B) Activated sludge settles at the same rate as raw sludge<br>C) Activated sludge settles slower than raw sludge<br>D) Activated sludge settles much faster than raw sludge<br>C) Activated sludge settles slower than raw sludge (v.1 pg 109)<\/p>\n\n\n\n<p>What should be mostly found in healthy activated sludge?<\/p>\n\n\n\n<p>A) Tiny flagellates<br>B) Amoeboids<br>C) Short Filaments<br>D) Free swimmers and stalked ciliates<br>D) Free swimmers and stalked ciliates (v.2 pg 120,124)<\/p>\n\n\n\n<p>One to two percent of the digester gas in an anaerobic consists of<\/p>\n\n\n\n<p>A) Hydrogen, Nitrogen, Hydrogen sulfide, and other gases<br>B) Methane<br>C) Carbon Dioxide<br>D) CH_4<br>A) Hydrogen, Nitrogen, Hydrogen sulfide, and other gases (v.2 pg 158)<\/p>\n\n\n\n<p>What is true during the colder winter months?<\/p>\n\n\n\n<p>A) Modify operations to decrease solids under aeration to provide less microorganisms to treat the BOD<br>B) Modify operations to increase solids under aeration to provide more microorganisms to treat the BOD<br>C) Biological activity will increase, which results in more overall sludge production<br>D) Microorganisms become more active<br>B) Modify operations to increase solids under aeration to provide more microorganisms to treat the BOD (v.2 pg 71)<\/p>\n\n\n\n<p>What type of sludge would you expect in an aeration tank if the content is dark and has low DO?<\/p>\n\n\n\n<p>A) Sludge that is heavy<br>B) Chlorinated Sludge<br>C) Septic Sludge<br>D) Healthy Sludge<br>C) Septic Sludge (v.2 pg 75)<\/p>\n\n\n\n<p>What could have happen if the volatile acid\/alkalinity ratio starts to increase, and corrective action is not taken immediately?<\/p>\n\n\n\n<p>A) Carbon dioxide content in the digester gas will decrease<br>B) Carbon monoxide content in the digester gas will fluctuate<br>C) pH of the digester sludge will increase<br>D) Carbon dioxide content in the digester gas will increase<br>D) Carbon dioxide content in the digester gas will increase (v.2 pg 191)<\/p>\n\n\n\n<p>What are screenings?<\/p>\n\n\n\n<p>A) Colloids<br>B) TDS<br>C) Pieces of wood, roots, rags, and other large debris<br>D) COD<br>C) Pieces of wood, roots, rags, and other large debris (v.1 pg 41)<\/p>\n\n\n\n<p>What happens when there is more food in the influent to the aeration tank?<\/p>\n\n\n\n<p>A) Less oxygen is required in the aeration tank<br>B) More oxygen is required in the aeration tank<br>C) Less organism activity takes place<br>D) Less oxidation takes place<br>B) More oxygen is required in the aeration tank (v.2 pg 19)<\/p>\n\n\n\n<p>What impact does temperature have on the reaction rate of microorganisms in wastewater?<\/p>\n\n\n\n<p>A) Reaction rate doubles with every 18 degree Fahrenheit increase in temperature until higher temperature inhibits biological activity<br>B) Reaction rate decreases by 20% with every 10 degree Fahrenheit increase in temperature<br>C) Reaction rate of microorganism is not impacted by temperature<br>D) Reaction rate goes to zero<br>A) Reaction rate doubles with every 18 degree Fahrenheit increase in temperature until higher<\/p>\n\n\n\n<p>What is commonly used to control the odor of hydrogen sulfide?<\/p>\n\n\n\n<p>A) Carbon Dioxide<br>B) Methane<br>C) Chlorine<br>D) Hydrogen<br>C) Chlorine (v.1 pg 398)<\/p>\n\n\n\n<p>What is used to determine the amount of microorganisms in the aeration tank?<\/p>\n\n\n\n<p>A) Mixed Liquor Suspended Solids (MLSS)<br>B) Influent TSS<br>C) BOD<br>D) Mixed Liquor Volatile Suspended Solids (MLVSS)<br>D) Mixed Liquor Volatile Suspended Solids (MLVSS) (v.2 pg 58)<\/p>\n\n\n\n<p>What could happen if the sludge line is isolated by closing the valves on each end for several days?<\/p>\n\n\n\n<p>A) It could result in water hammer<br>B) Cavitation<br>C) Gas production could increase the internal pressure and cause the line to fail<br>D) The aerobic condition will cause Zoolgleal mass to grow in large numbers.<br>C) Gas production could increase the internal pressure and cause the line to fail (v.2 pg 152)<\/p>\n\n\n\n<p>Which is true about chlorine gas?<\/p>\n\n\n\n<p>A) It is 2.5 times lighter than air<br>B) it is 2.5 times heavier than air<br>C) It is 1.5 times heavier than air<br>D) It is 1.5 times lighter than air<br>B) it is 2.5 times heavier than air (v.1 pg 375)<\/p>\n\n\n\n<p>Which of the following is typically treated by biological processes?<\/p>\n\n\n\n<p>A) Roots and rags<br>B) Sand and eggshells<br>C) Cinders<br>D) Dissolved and non settable organic material<br>D) Dissolved and non settable organic material (v.1 pg 46)<\/p>\n\n\n\n<p>Which document is a written record that accurately traces the custody of wastewater samples through all phases of a monitoring program?<\/p>\n\n\n\n<p>A) Wastewater Lab Analysis form<br>B) NEPA<br>C) Chain of Custody form<br>D) Diagnostic form<br>C) Chain of Custody form (v.2 pg 498)<\/p>\n\n\n\n<p>What could cause a sudden drop in pH of the influent?<\/p>\n\n\n\n<p>A) Acidic chemical in the influent<br>B) A strong base was dumped into the collection system<br>C) Ammonia from a factory was discharged into the sewer<br>D) The influent contained sodium hydroxide<br>A) Acidic chemical in the influent (v.2 pg 579)<\/p>\n\n\n\n<p>What is the recommended daily maintenance activity for a clarifier?<\/p>\n\n\n\n<p>A) Dewater the clarifier by draining the wastewater<br>B) Repaint metal surfaces that have lost their protective coating<br>C) Hose down walls, floor and equipment inside the clarifiers<br>D) Inspect chains, sprockets, and flights.<br>D) Inspect chains, sprockets, and flights (v.1 pg 118)<\/p>\n\n\n\n<p>Which of the following could be the cause of ponding in a trickling filter?<\/p>\n\n\n\n<p>A) Hydraulic loading is too low<br>B) Clogging of distributor orifices<br>C) Excessive organic loading<br>D) Denitrification<br>C) Excessive organic loading (v.1 pg 192)<\/p>\n\n\n\n<p>What could happen if the dissolved oxygen content in the aeration tank is too low?<\/p>\n\n\n\n<p>A) Pinpoint floc will develop<br>B) Filamentous organisms could thrive and prevent the sludge sludge floc from settling properly in the secondary clarifier<br>C) Settling will improve in the secondary clarifier<br>D) Sludge bulking will be eliminated<br>B) Filamentous organisms could thrive and prevent the sludge sludge floc from settling properly in the secondary clarifier (v.1 pg 254)<\/p>\n\n\n\n<p>What is the expected BOD removal efficiency in a facultative pond?<\/p>\n\n\n\n<p>A) Mostly between 40 to 50%<br>B) Mostly between 30 to 40%<br>C) Mostly between 20 to 30%<br>D) Mostly between 70 to 80%<br>D) Mostly between 70 to 80% (v.1 pg 317)<\/p>\n\n\n\n<p>What is a chloramine?<\/p>\n\n\n\n<p>A) Free chlorine<br>B) A chemical that is formed when chlorine reacts with iron<br>C) Combined chlorine- a chemical that is formed when chlorine reacts with ammonia<br>D) A chemical that is formed when chlorine reacts with air.<br>C) Combined chlorine- a chemical that is formed when chlorine reacts with ammonia (v.1 pg 350)<\/p>\n\n\n\n<p>What is sludge bulking in an activated sludge process?<\/p>\n\n\n\n<p>A) When mixed liquor solids settle slowly and compact to a limited extent<br>B) When old sludge denitrify and cause sludge to rise as a result of gastrification<br>C) When sludge form large aggregates and cause sludge to settle quickly<br>D) When compaction in the secondary clarifier is improved due to chemical injection<br>A) When mixed liquor solids settle slowly and compact to a limited extent (v.2 pg 71)<\/p>\n\n\n\n<p>What is the most common imbalance in an anaerobic digester?<\/p>\n\n\n\n<p>A) Excess methane formation<br>B) Excess nitrogen formation<br>C) Excess acid formation<br>D) Excess carbon dioxide formation<br>C) Excess acid formation (v.2 pg 148)<\/p>\n\n\n\n<p>What is the only reliable method of detecting hydrogen sulfide?<\/p>\n\n\n\n<p>A) Sense of smell<br>B) Atmospheric monitoring<br>C) Color titration<br>D) Lab test<br>B) Atmospheric monitoring (v.2 pg 271)<\/p>\n\n\n\n<p>What is sludge age?<\/p>\n\n\n\n<p>A) An expression of the average time that a microorganism will spend in the activated sludge process, and calculated using total suspended solids removed from the process<br>B) A measure of food provided to bacteria in an aeration tank<br>C) The theoretical time required for water to pass through a tank at any given flowrate<br>D) A rough indicator of the length of time a pound of solids is maintained under aeration<br>D) A rough indicator of the length of time a pound of solids is maintained under aeration (v.2 pg 519)<\/p>\n\n\n\n<p>What is one of the benefits of a COD test over a BOD test?<\/p>\n\n\n\n<p>A) COD test does not require any chemicals to perform the test<br>B) COD test will easily predict the effects of an effluent on the DO in receiving waters<br>C) Shorter test period<br>D) COD test is capable of measuring the biodegradability of matter<br>C) Shorter test period (v.2 pg 541)<\/p>\n\n\n\n<p>What is the typical detention time for a primary clarifier?<\/p>\n\n\n\n<p>A) 3 to 4 hours<br>B) 30 minutes<br>C) 6 hours<br>D) 1.5 to 2 hours<br>D) 1.5 to 2 hours (v.1 pg 43)<\/p>\n\n\n\n<p>If you are testing the pH of a wastewater sample, what is the maximum recommended holding time?<\/p>\n\n\n\n<p>A) 5 days<br>B) It must be tested immediately<br>C) 24 hours<br>D) 36 hours<br>B) It must be tested immediately (v.2 pg 502)<\/p>\n\n\n\n<p>What could cause short circuiting in a clarifier?<\/p>\n\n\n\n<p>A) Sludge composition<br>B) Reduction in flowrate<br>C) Uneven weir settings<br>D) Broken sludge pump<br>C) Uneven weir settings (v.1 pg 125)<\/p>\n\n\n\n<p>What could cause the slime growth on a rotating biological contactor to appear black?<\/p>\n\n\n\n<p>A) It could indicate solids or organic overloading<br>B) High DO in the plant effluent<br>C) Lack of BOD in the influent to the rotating biological contactor<br>D) Low hydraulic loading<br>A) It could indicate solids or organic overloading (v.1 pg 228)<\/p>\n\n\n\n<p>What is an air gap?<\/p>\n\n\n\n<p>A) A distance between blowers in an activated sludge system<br>B) The vertical distance between the surface of wastewater and the top of basin<br>C) Backflow prevention<br>D) Type of aeration equipment<br>C) Backflow prevention (v.1 pg 503)<\/p>\n\n\n\n<p>Which is true about chlorine demand?<\/p>\n\n\n\n<p>A) Chlorine demand= Chlorine residual + Chlorine dose<br>B) Chlorine demand= Chlorine does x Chlorine residual<br>C) Chlorine demand= Chlorine residual &#8211; Chlorine dose<br>D) Chlorine demand= Chlorine dose &#8211; Chlorine residual<br>D) Chlorine demand= Chlorine dose &#8211; Chlorine residual (v.1 pg 352)<\/p>\n\n\n\n<p>What is accomplished by the activated sludge process?<\/p>\n\n\n\n<p>A) Anaerobic bacteria use SO_4 to eat incoming volatile solids<br>B) Remove soluble or finely divided suspended materials<br>C) Anoxic microorganisms destroy incoming BOD<br>D) Zoogleal breaks down influent organics<br>B) Remove soluble or finely divided suspended materials (v.2 pg 16)<\/p>\n\n\n\n<p>What is the carbon dioxide content of a properly functioning anaerobic digester?<\/p>\n\n\n\n<p>A) 65 to 70% by volume<br>B) 1 to 2% by volume<br>C) 30 to 35% by volume<br>D) 40 to 60% by volume<br>C) 30 to 35% by volume (v.2 pg 158)<\/p>\n\n\n\n<p>Which of the following is a collection of individual samples obtained at regular intervals?<\/p>\n\n\n\n<p>A) Grab<br>B) Culmination<br>C) Comprehensive<br>D) Composite<br>D) Composite (v.2 pg 499)<\/p>\n\n\n\n<p>What is the most common piece of laboratory equipment, which is used mainly to mix chemicals and measure approximate volumes?<\/p>\n\n\n\n<p>A) Beaker<br>B) Graduated cylinder<br>C) Pipet<br>D) Flask<br>A) Beaker(v.2 pg 479)<\/p>\n\n\n\n<p>What are colloids?<\/p>\n\n\n\n<p>A) Solids that settle rapidly<br>B) Dissolved solids<br>C) Solids found in the grit channel<br>D) Very small, finely divided solids that remain dispersed in a liquid for a long time<br>D) Very small, finely divided solids that remain dispersed in a liquid for a long time (v.1 pg 22,144)<\/p>\n\n\n\n<p>What is the most common type of grit collector?<\/p>\n\n\n\n<p>A) Deflectors<br>B) Weirs<br>C) Chain driven scrapers called &#8220;flights&#8221;<br>D) Parshall flume<br>C) Chain driven scrapers called &#8220;flights&#8221; (v.1 pg 87)<\/p>\n\n\n\n<p>What is true about surface loading and detention time?<\/p>\n\n\n\n<p>A) They stay fairly constant throughout the day<br>B) They are impacted by the influent BOD<br>C) They are indirectly related to flow<br>D) They are directly related to flow<br>D) They are directly related to flow (v.1 pg 118)<\/p>\n\n\n\n<p>What is the slime growth on a trickling filter called?<\/p>\n\n\n\n<p>A) Filamentous bacteria<br>B) Zoogleal film<br>C) Stalked ciliate<br>D) Acid formers<br>B) Zoogleal film (v.1 pg 169)<\/p>\n\n\n\n<p>What should be done if you observe a small, steady stream of water leakage from the pump packings?<\/p>\n\n\n\n<p>A) tighten the packings until they are water tight<br>B) Replace the packing<br>C) Do nothing. The leakage is required to cool and lubricate the dynamic surface<br>D) Replace the pump<br>C) Do nothing. The leakage is required to cool and lubricate the dynamic surface (v.2 pg 344)<\/p>\n\n\n\n<p>What should be done if the SVI is high and there is an excess of normal filamentous microorganisms in the activated sludge process?<\/p>\n\n\n\n<p>A) Inject hydrogen peroxide in the secondary effluent<br>B) Make sure DO levels is very low in the aeration tank<br>C) Decrease MLSS and sludge age<br>D) Chlorinate the return activated sludge<br>D) Chlorinate the return activated sludge (v.2 pg 60)<\/p>\n\n\n\n<p>When is confined space considered oxygen deficient?<\/p>\n\n\n\n<p>A) In atmosphere where oxygen content is less than 19.5% by volume<br>B) In atmosphere where oxygen content is less than 23.5% by volume<br>C) In atmosphere where oxygen content is less more than 23.5% by volume<br>D) In atmosphere where oxygen content is less than 29.5% by volume<br>A) In atmosphere where oxygen content is less than 19.5% by volume (v.2 pg 267)<\/p>\n\n\n\n<p>Which of the following is not true about chlorine gas?<\/p>\n\n\n\n<p>A) 2.5 times heavier than air<br>B) Extremely toxic<br>C) Common chlorine gas concentration at the treatment plants is 12.5%<br>D) Corrosive in moist atmosphere<br>C) Common chlorine gas concentration at the treatment plants is 12.5% (v.1 pg 375)<\/p>\n\n\n\n<p>What is a &#8220;dead spot&#8221; in an activated sludge process?<\/p>\n\n\n\n<p>A) An area in the secondary clarifier with rising sludge<br>B) An area in the aeration tank that has insufficient mixing<br>C) An area in the aeration tank that has high concentration of DO<br>D) An area in the secondary clarifier with may dead viruses<br>B) An area in the aeration tank that has insufficient mixing<\/p>\n\n\n\n<p>Which of the following is an improper way to control an anaerobic digester?<\/p>\n\n\n\n<p>A) Control the loading rate or food supply<br>B) Control the volatile acid\/alkalinity relationship<br>C) Control mixing<br>D) Control the acid formation so that it is larger than the methane formation<br>D) Control the acid formation so that it is larger than the methane formation (v.2 pg 148)<\/p>\n\n\n\n<p>Which of the following is not true about permitted confined space entry?<\/p>\n\n\n\n<p>A) Wear an approved harness with an attached line<br>B) If the entry is made through a top opening, use a hoisting device with a harness that suspends a person in an upright position<br>C) Testing for atmospheric hazards is not required as long as a blower is in use<br>D) Wear protective clothing when entering a confined space that contains corrosive substances or other substances harmful to the skin<br>C) Testing for atmospheric hazards is not required as long as a blower is in use (v.2 pg 270)<\/p>\n\n\n\n<p>What is a MSDS?<\/p>\n\n\n\n<p>A) A federal law that is designed to protect the health and safety of workers<br>B) A condition in which a persons nose is no longer able to detect odor from a chemical<br>C) A document that contains important information about a chemical, such as safe exposure level, flammability rating, and first aid procedures<br>D A publication written by the federal government that contains all regulations, including those that affect safety and the environment<br>C) A document that contains important information about a chemical, such as safe exposure level, flammability rating, and first aid procedures (v.2 pg 728)<\/p>\n\n\n\n<p>How often should grit be removed from the grit channel?<\/p>\n\n\n\n<p>A) Weekly<br>B) Monthly<br>C) Bi-weekly<br>D) Daily<br>D) Daily (v.1 pg 87)<\/p>\n\n\n\n<p>What is the typical removal efficiency from bacteria in a primary clarifier?<\/p>\n\n\n\n<p>A) 0-5%<br>B) 25-75%<br>C) 5-10%<br>D) 10-20%<br>B) 25-75% (v.1 pg 129)<\/p>\n\n\n\n<p>What problem could most likely cause a centrifugal pump to discharge at a reduced rate?<\/p>\n\n\n\n<p>A) Damaged impeller<br>B) Slight water leak at the packings<br>C) Pumping against less resistance<br>D) Seal water is dripping slowly<br>A) Damaged impeller (v.1 pg 182)<\/p>\n\n\n\n<p>What is the two categories of coliform bacteria?<\/p>\n\n\n\n<p>A) Lactose and lauryl tryptose<br>B) Primary and secondary<br>C) Free swimming and stalked<br>D) Total and Fecal<br>D) Total and Fecal (v.2 pg 552)<\/p>\n\n\n\n<p>Which of the following is true about the extended aeration process?<\/p>\n\n\n\n<p>A) Wasting is not necessary to maintain proper control of the process<br>B) It produces more waste than conventional activated sludge process<br>C) It has low F\/M ratio<br>D) It has low MLSS concentration<br>C) It has low F\/M ratio (v.1 pg 257)<\/p>\n\n\n\n<p>What type of disinfection is gaining popularity, and expected to become a practical alternative to chlorination?<\/p>\n\n\n\n<p>A) Sulfur dioxide<br>B) Ultraviolet (UV) disinfection<br>C) Aqueous ammonia<br>D) Caustic soda<br>B) Ultraviolet (UV) disinfection (v.1 pg 303)<\/p>\n\n\n\n<p>Where is the proper sampling location for an effluent from a wastewater treatment plant?<\/p>\n\n\n\n<p>A) Next to the chlorinator equipment<br>B) At the end of a solids handling facility<br>C) Prior to discharge into receiving waters<br>D) At the head of a chlorine contact chamber<br>C) Prior to discharge into receiving waters<\/p>\n\n\n\n<p>What is true if the F\/M ratio increases?<\/p>\n\n\n\n<p>A) Less DO is required<br>B) Less BOD is available<br>C) DO will not be affected by an increase in F\/M ratio<br>D) More DO is needed<br>D) More DO is needed (v.2 pg 53)<\/p>\n\n\n\n<p>Who must be included in a hearing conservation program to prevent hearing loss?<\/p>\n\n\n\n<p>A) Employees whose normal noise exposure equals or exceeds 65 decibels<br>B) Employees whose normal noise exposure equals or exceeds an 8 hour time weighted average of 85 decibels<br>C) Employees whose normal noise exposure exceeds 45 decibels at any time<br>D) Employees whose normal noise exposure exceeds and 8 hour time weighted average of 25 decibels<br>B) Employees whose normal noise exposure equals or exceeds an 8 hour time weighted average of 85 decibels (v.2 pg 277)<\/p>\n\n\n\n<p>What is a major cause of repeated sludge bulk?<\/p>\n\n\n\n<p>A) High pH<br>B) High DO<br>C) High food to mircoorganism loading rates<br>D) High nutrient concentration<br>C) High food to mircoorganism loading rates (v.2 pg 71)<\/p>\n\n\n\n<p>How can the efficiency of a trickling filter be improved?<\/p>\n\n\n\n<p>A) Raise the distributor arm<br>B) Reduce the size of the ventilation ports<br>C) Decrease the amount of the filter media<br>D) Add recirculation<br>D) Add recirculation (v.1 pg 175)<\/p>\n\n\n\n<p>During the day, what typically happens to a pond as a result of the algae?<\/p>\n\n\n\n<p>A) Algae uses carbon dioxide, which raises pH<br>B) Algae produces carbon dioxide, which lowers pH<br>C) Algae consumes carbon dioxide, which lower pH<br>D) Algae releases carbon dioxide, which raises pH<br>A) Algae uses carbon dioxide, which raises pH (v.1 pg 299)<\/p>\n\n\n\n<p>What should be done to find a small chlorine leak?<\/p>\n\n\n\n<p>A) Spray hypocloric acid near the suspected leak<br>B) Tie a rag on a stick, dip the rag in a strong ammonia solution, and hold the rag near the suspected points<br>C) Release carbon dioxide to trace the leak<br>D) Apply a small quantity of citric acid near the leak<br>B) Tie a rag on a stick, dip the rag in a strong ammonia solution, and hold the rag near the suspected points (v.1 pg 386)<\/p>\n\n\n\n<p>What should you do if there is a thick, dark foam on the surface of an aeration tank?<\/p>\n\n\n\n<p>A) Increase the sludge wasting<br>B) Decrease sludge wasting<br>C) Maintain current MLSS concentration<br>D) Increase the mircoorganism population<br>A) Increase the sludge wasting (v.2 pg 53)<\/p>\n\n\n\n<p>Why is mixing important in an anaerobic digester?<\/p>\n\n\n\n<p>A) Increases the build up of grit<br>B) Speeds up digestion rate<br>C) Achieves heterogeneous content in the digester<br>D) Forms a scum blanket<br>B) Speeds up digestion rate (v.2 pg 176)<\/p>\n\n\n\n<p>Where is the correct location for a vent inside a room storing chlorine gas?<\/p>\n\n\n\n<p>A) 12 inches below the ceiling<br>B) At nose level<br>C) Within 12 inches of the floor<br>D) At the highest point in the room<br>C) Within 12 inches of the floor (v.1 pg 396)<\/p>\n\n\n\n<p>What is the purpose of the seal at the stuffing box in a pump?<\/p>\n\n\n\n<p>A) Increases the discharge flowrate of the pump<br>B) Minimizes cavitation<br>C) Increases brake horsepower<br>D) Lubricates the packing<br>D) Lubricates the packing (v.2 pg 344)<\/p>\n\n\n\n<p>What is the incubation period for the BOD test?<\/p>\n\n\n\n<p>A) Five days +\/- 3 hours<br>B) Five days +\/- 1 hours<br>C) Five days +\/-4 hours<br>D) Five days +\/- 2 hours<br>A) Five days +\/- 3 hours (v.2 pg 574)<\/p>\n\n\n\n<p>What could happen if you are exposed to very high concentration of hydrogen sulfide?<\/p>\n\n\n\n<p>A) Swelling of the hand<br>B) Numbness of the legs<br>C) It could quickly lead to death<br>D) Develop skin rash<br>C) It could quickly lead to death (v.2 pg 268)<\/p>\n\n\n\n<p>What causes primary effluent to become black and odorous?<\/p>\n\n\n\n<p>A) Excessive sludge pumping<br>B) Oil leak from the sludge pump<br>C) Crack in the launder<br>D) Improper sludge removal from the clarifier<br>D) Improper sludge removal from the clarifier (v.1 pg 123)<\/p>\n\n\n\n<p>What is a biomass?<\/p>\n\n\n\n<p>A) Bacteria that change ammonia into oxidized nitrogen<br>B) Organisms that grow in a thread or filamentous form<br>C) A mass of organic material consisting of living organisms that feed on the wastes in sewage<br>D) Wastes such as sand, salt, and calcium that are present in the plant influent<br>C) A mass of organic material consisting of living organisms that feed on the wastes in sewage (v.2 pg 816)<\/p>\n\n\n\n<p>What is the color of a pond that is operating properly?<\/p>\n\n\n\n<p>A) Brown<br>B) Deep green color<br>C) Clear<br>D) Tan<br>B) Deep green color (v.1 pg 309)<\/p>\n\n\n\n<p>What does healthy activated sludge smell like?<\/p>\n\n\n\n<p>A) Chlorine<br>B) Raw sewage<br>C) Rotten eggs<br>D) Earthy<br>D) Earthy<\/p>\n\n\n\n<p>Which law regulates wastewater discharge to receiving water?<\/p>\n\n\n\n<p>A) Wastewater Act<br>B) Clean Water Act<br>C) National Discharge Act<br>D) Federal Effluent Act<br>B) Clean Water Act<\/p>\n\n\n\n<p>1 mg\/l is the same as 1 part per billion (ppb)<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 468)<\/p>\n\n\n\n<p>A SCADA system is capable of monitoring and controlling equipment from a remote location<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 627)<\/p>\n\n\n\n<p>A Discharge Monitoring Report is typically submitted to the regulatory agency on a daily basis<\/p>\n\n\n\n<p>True or False<br>False<\/p>\n\n\n\n<p>A mechanical seal is used to prevent leaks between the pump casing and shaft.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 356)<\/p>\n\n\n\n<p>Alkalinity is the capacity of a liquid to neutralize a base.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 813)<\/p>\n\n\n\n<p>Typical mixed liquor suspended solids concentration is 1,000 to 4,500 mg\/l.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 54)<\/p>\n\n\n\n<p>Turbidity is caused by suspended matters.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 606)<\/p>\n\n\n\n<p>Algae is not essential to the successful operation of both aerobic and facultative ponds.<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 299)<\/p>\n\n\n\n<p>The addition of acid and CO2 will lower the pH of wastewater.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 299)<\/p>\n\n\n\n<p>Hydrogen sulfide will deteriorate concrete structures.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 20)<\/p>\n\n\n\n<p>The higher the pH, the better the disinfection<br>False (v.1 pg 352)<\/p>\n\n\n\n<p>Maintain a dissolved oxygen concentration of 12 to 14 mg\/l in the aeration tank.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 53)<\/p>\n\n\n\n<p>When the velocity of the wastewater in a clarifier is greater in some sections than others, it will lead to short-circuiting.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 135)<\/p>\n\n\n\n<p>The F\/M ratio will decrease when the microorganism population in the aeration tank increases.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 16)<\/p>\n\n\n\n<p>Algae growth will be faster when there is less sunlight.<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 309)<\/p>\n\n\n\n<p>The higher the temperature, the more rapid the rate of disinfection.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 352)<\/p>\n\n\n\n<p>One of the benefits of recirculation for a trickling filter is that it decreases the contact time of the wastewater with the biological film.<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 175)<\/p>\n\n\n\n<p>Maintaining a constant temperature in an anaerobic digester is one way to prevent foaming from recurring.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 187)<\/p>\n\n\n\n<p>Preventative maintenance is a proactive, programmed, and systematic approach to maintenance.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 718)<\/p>\n\n\n\n<p>Abnormal operation in a pond will not occur if it is overloaded with BOD.<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 307)<\/p>\n\n\n\n<p>Anaerobic decomposition of sewage will release hydrogen sulfide.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 20)<\/p>\n\n\n\n<p>Always pour water into acid, and never the other way around.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 302)<\/p>\n\n\n\n<p>Scum escaping in the clarifier effluent could be caused by hydraulic overload.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 124)<\/p>\n\n\n\n<p>Operate an activated sludge system at low MCRT if you have limited aeration capacity.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 59)<\/p>\n\n\n\n<p>Chlorine gas is brown in color.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 268)<\/p>\n\n\n\n<p>Typical suspended solids concentration of domestic influent wastewater is 150 to 400 mg\/l.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 54)<\/p>\n\n\n\n<p>Poor ventilation of a trickling filter could lead to odor problems.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 193)<\/p>\n\n\n\n<p>Sulfur dioxide is used to dechlorinate the effluent prior to discharge to protect aquatic organisms in the receiving waters.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 401)<\/p>\n\n\n\n<p>MCRT describes the average residence time of the activated sludge particle in the return sludge pipe.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 522)<\/p>\n\n\n\n<p>Free chlorine combines with water to form hypochlorous and hydorchloric acids.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 349)<\/p>\n\n\n\n<p>The trickling filter can be controlled by changing the loadings based on sludge age, F\/M ratio, or MCRT.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 58)<\/p>\n\n\n\n<p>The MPN test for coliform does not test for individual pathogenic microorganisms, but uses coliform as an indicator organism to estimate the microorganism population.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 352)<\/p>\n\n\n\n<p>Mixed liquor volatile suspended solids (MLVSS) is used to determine the amount of microorganisms in the aeration tank to treat the incoming waste.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 58)<\/p>\n\n\n\n<p>A manhole, sump, or vault, can be entered without the following confined space entry procedures if it appears safe.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 271)<\/p>\n\n\n\n<p>An increase in the volatile acids\/alkalinity ratio in an anaerobic digester indicates that a problem is developing.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 191)<\/p>\n\n\n\n<p>Chain driven scrappers called flights are commonly used as mechanical grit collectors.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 87)<\/p>\n\n\n\n<p>A facultative bacteria is capable of living under an aerobic condition, but not in an anaerobic condition.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 826)<\/p>\n\n\n\n<p>An impeller is an important part of a centrifugal pump that spins the liquid at high speed.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 339)<\/p>\n\n\n\n<p>Hot bearings in a blower could be caused by defective bearings.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 80)<\/p>\n\n\n\n<p>Class A fire extinguisher should be used for an electrical fire.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 496)<\/p>\n\n\n\n<p>Scum from primary clarifiers consists mainly of grease and other floatable materials.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 183)<\/p>\n\n\n\n<p>One of the ways to resolve an increase in the volatile acid\/alkalinity ratio in an anaerobic digester is to decrease raw sludge feed rates.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 191)<\/p>\n\n\n\n<p>Sludge will not become septic when it remains in a channel or basin for an extended period of time.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 72)<\/p>\n\n\n\n<p>Shallow ponds that are used to treat wastewater are typically 3 to 5 feet deep.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 294)<\/p>\n\n\n\n<p>A slight seal leakage should be observed when a pump is operating to keep the packings cool.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 414)<\/p>\n\n\n\n<p>Total solids = volatile solids + suspended solids<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 22)<\/p>\n\n\n\n<p>The purpose of sludge wasting in an activated sludge process is to control the amount of solids in the primary treatment process.<\/p>\n\n\n\n<p>True or False<br>False (v.2 pg 57)<\/p>\n\n\n\n<p>Chlorine gas in not flammable.<\/p>\n\n\n\n<p>True or False<br>True (v.2 pg 268)<\/p>\n\n\n\n<p>Screening is a part of the pretreatment process that removes larger debris, such as rocks, cans, and bottle.<\/p>\n\n\n\n<p>True or False<br>True (v.1 pg 65)<\/p>\n\n\n\n<p>The best velocity through a grit chamber is 3 foot per second.<\/p>\n\n\n\n<p>True or False<br>False (v.1 pg 84)<\/p>\n\n\n\n<p>What is the main purpose of the activated sludge process?<\/p>\n\n\n\n<p>A) Removal of sand and pebbles<br>B) Removal of settleable solids and floating scum<br>C) Organic solids are liquefied and the solids volume is reduced<br>D) Removal of soluble or finely divided suspended materials that were not removed by the previous treatment.<br>D) Removal of soluble or finely divided suspended materials that were not removed by the previous treatment. (v.2 pg 16)<\/p>\n\n\n\n<p>Where is the primary sludge typically pumped to ?<\/p>\n\n\n\n<p>A) Grit classifier<br>B) Centrifuge<br>C) Sludge digester<br>D) Sludge drying bed<br>C) Sludge digester (v.2 pg 148)<\/p>\n\n\n\n<p>What problem is caused by denitrification?<\/p>\n\n\n\n<p>A) Excessive settling of solids<br>B) Rising sludge in secondary clarifier<br>C) Very short detention time<br>D) Conversion of ammonia to oxidized nitrogen<br>B) Rising sludge in secondary clarifier (v.2 pg 73)<\/p>\n\n\n\n<p>What condition is necessary to perform a BOD test?<\/p>\n\n\n\n<p>A) 5 days at 20 degrees Celsius<br>B) 5 days at 25 degrees Celsius<br>C) 5 days at 30 degrees Celsius<br>D) 5 days at 35 degrees Celsius<br>A) 5 days at 20 degrees Celsius (v.2 pg 574)<\/p>\n\n\n\n<p>What is a fusible plug?<\/p>\n\n\n\n<p>A) a plug on the bottom of a valve to drain sludge during maintenance<br>B) a plug that can be fused to a diffuser in an aeration tank to permanently seal the outlet<br>C) a safety device used to prevent build up of excessive pressure in a chlorine cylinder<br>D) a plug used to seal a leak on a polymer storage tank<br>C) a safety device used to prevent build up of excessive pressure in a chlorine cylinder (v.1 pg 378)<\/p>\n\n\n\n<p>What is usually the last indicator to change in an anaerobic digester that is becoming sour?<\/p>\n\n\n\n<p>A) Volatile acid\/alkalinity ratio<br>B) Temperature<br>C) Color<br>D) pH<br>D) pH (v.2 pg 192)<\/p>\n\n\n\n<p>What information is needed to calculate the F\/M ratio?<\/p>\n\n\n\n<p>A) BOD and MLSS<br>B) BOD and MLVSS<br>C) TSS and MLSS<br>D) MLSS and settled sludge volume<br>B) BOD and MLVSS (v.2 pg 16)<\/p>\n\n\n\n<p>Which chemical is commonly used to control hydrogen sulfide gas?<\/p>\n\n\n\n<p>A) Chlorine<br>B) Ammonia<br>C) Carbon dioxide<br>D) Sodium dioxide<br>A) Chlorine (v.2 pg 506)<\/p>\n\n\n\n<p>What could cause a trickling filter to operate less effectively?<\/p>\n\n\n\n<p>A) Blower inefficiency<br>B) Recirculation<br>C) Plastic Media<br>D) Ponding<br>D) Ponding (v.1 pg 175)<\/p>\n\n\n\n<p>What is MPN?<\/p>\n\n\n\n<p>A) A type of surfactant found in wastewater<br>B) A clump of organic material<br>C) Most Probable Number of coliform group organisms per unit volume of sample water<br>D) A number that indicates the tendency of activated sludge solids to thicken<br>C) Most Probable Number of coliform group organisms per unit volume of sample water (v.2 pg 835)<\/p>\n\n\n\n<p>What is true regarding dissolved solids?<\/p>\n\n\n\n<p>A) They will get caught on a filter<br>B) They are often called colloidal particles<br>C) They will pass through a filter<br>D) They are all inorganic solids<br>C) They will pass through a filter (v.1 pg 21)<\/p>\n\n\n\n<p>Why is chlorine sometimes added at the headworks of the plant?<\/p>\n\n\n\n<p>A) To address denitrification<br>B) Control odor<br>C) To address sludge bulking<br>D) Control fly problems<br>B) Control odor (v.1 pg 354)<\/p>\n\n\n\n<p>What is the purpose of a launder in a primary clarifier?<\/p>\n\n\n\n<p>A) Collects the primary effluent that flows over the weir and conveys it towards the next treatment process<br>B) A pipe that conveys wastewater to the influent of the clarifier<br>C) Blades that scrape sludge from the bottom of the clarifier to the sump<br>D) A power unit that rotates the collector<br>A) Collects the primary effluent that flows over the weir and conveys it towards the next treatment process (v.1 pg 115)<\/p>\n\n\n\n<p>What is the best way to communicate important information to employees?<\/p>\n\n\n\n<p>A) Memo<br>B) Meeting in-person<br>C) Bulletin board in break room<br>D) Send an email<br>B) Meeting in-person (v.2 pg 708-710)<\/p>\n\n\n\n<p>What problems might arise from tightening a gland in a pump?<\/p>\n\n\n\n<p>A) Excessive leakage<br>B) Water hammer<br>C) Wear on the shaft or shaft sleeve<br>D) Cavitation<br>C) Wear on the shaft or shaft sleeve (v.2 pg 344)<\/p>\n\n\n\n<p>What could the oxygen uptake rate test be used for?<\/p>\n\n\n\n<p>A) Determine SVI<br>B) Obtain the F\/M ratio<br>C) Obtain pH of the wastewater<br>D) Detect toxicity in the activated sludge process<br>D) Detect toxicity in the activated sludge process<\/p>\n\n\n\n<p>What does anaerobic bacteria require for metabolism?<\/p>\n\n\n\n<p>A) Dissolved oxygen<br>B) Oxygen from nitrate<br>C) They obtain oxygen by breaking down chemical compounds that contain oxygen, such as sulfate<br>D) Carbon<br>C) They obtain oxygen by breaking down chemical compounds that contain oxygen, such as sulfate (v.2 pg 814)<\/p>\n\n\n\n<p>Which of the following is used to dewater sludge?<\/p>\n\n\n\n<p>A) All choices (B,C,D)<br>B) Drying bed<br>C) Centrifuge<br>D) Vacuum filter<br>A) All choices (B,C,D) (v.1 pg 49)<\/p>\n\n\n\n<p>Which of the following is true about algae in a pond?<\/p>\n\n\n\n<p>A) During the day, it consumes oxygen and releases CO2 for the bacteria in the pond<br>B) During the day, it consumes H2S and releases oxygen for the anaerobic bacteria in the pond<br>C) During the day, it consumes H2S and releases CO2 for the anaerobic bacteria<br>D) During the day, it consumes CO2 and releases oxygen for the aerobic bacteria in the pond<br>D) During the day, it consumes CO2 and releases oxygen for the aerobic bacteria in the pond (v.1 pg 299)<\/p>\n\n\n\n<p>What is the typical BOD in the secondary effluent?<\/p>\n\n\n\n<p>A) between 50 to 100 mg\/l<br>B) between 120 to 300 mg\/l<br>C) Between 5 to 30 mg\/l<br>D) Between 300 to 350 mg\/l<br>C) Between 5 to 30 mg\/l (v.2 pg 573)<\/p>\n\n\n\n<p>What should be done to a chlorine container if liquid chlorine is leaking?<\/p>\n\n\n\n<p>A) Turn it over so that the leaking side is on the bottom to seal the leak<br>B) Turn it to the side<br>C) Apply water on the chlorine leak to slow down the leakage<br>D) Turn it over so that the leaking side is on the top<br>D) Turn it over so that the leaking side is on the top (v.1 pg 388)<\/p>\n\n\n\n<p>In a domestic wastewater system, how many pounds of oxygen are used each day by the microorganisms for each person using the system?<\/p>\n\n\n\n<p>A) 1.3 lb\/day\/person<br>B) 0.17 lb\/day\/person<br>C) 2.4 lbs\/day\/person<br>D) 3.5 lbs\/day\/person<br>B) 0.17 lb\/day\/person (v.1 pg 326)<\/p>\n\n\n\n<p>What terminology indicates the time required to fill a basin at a given flowrate?<\/p>\n\n\n\n<p>A) Detention time<br>B) Short-Circuiting<br>C) Hydraulic loading rate<br>D) Weir overflow rate<br>A) Detention time (v.1 pg 513)<\/p>\n\n\n\n<p>What could happen if the intake of a progressing cavity pump in not kept wet?<\/p>\n\n\n\n<p>A) Increase in head<br>B) Damage to pump<br>C) Slight decrease in flowrate<br>D) Incremental increase in pressure<br>B) Damage to pump<\/p>\n\n\n\n<p>How should you operate an anaerobic digester?<\/p>\n\n\n\n<p>A) The rate of acid formation is more than the methane formation<br>B) The rate of acid formation is less than the methane formation<br>C) The rate of acid formation and methane formation are approximately equal<br>D) The rate of acid formation is predominant and methane formation is negligible<br>C) The rate of acid formation and methane formation are approximately equal (v.2 pg 148)<\/p>\n\n\n\n<p>What is the purpose of a check valve?<\/p>\n\n\n\n<p>A) To isolate a clarifier for maintenance<br>B) To stop flow from entering the headworks<br>C) To throttle flow by turning the nut<br>D) Prevent liquid form flowing in the reverse direction<br>D) Prevent liquid form flowing in the reverse direction (v.2 pg 369)<\/p>\n\n\n\n<p>Which of the following is the best way to detect oxygen deficiency in a confined space?<\/p>\n\n\n\n<p>A) Reliable and calibrated gas monitor\/detector<br>B) Check for odor<br>C) Colormetric test<br>D) DPD<br>A) Reliable and calibrated gas monitor\/detector (v.2 pg 267)<\/p>\n\n\n\n<p>What should be done if filamentous organisms become a problem in the mixed liquor?<\/p>\n\n\n\n<p>A) Lower the pH to 5<br>B) Lower the MCRT to less than 4 days<br>C) Decrease sludge return rate and increase wasting<br>D) Increase DO in aeration tank<br>D) Increase DO in aeration tank (v.2 pg 74)<\/p>\n\n\n\n<p>What is the solids content of a good, thick primary sludge?<\/p>\n\n\n\n<p>A) 0.1 to 0.8% dry solids<br>B) 1 to 2.5% dry solids<br>C) 4 to 8% dry solids<br>D) 8 to 10% dry solids<br>C) 4 to 8% dry solids (v.1 pg 130)<\/p>\n\n\n\n<p>What must be done if you get chlorine in your eyes?<\/p>\n\n\n\n<p>A) Wash eyes with HCl<br>B) Chlorine must be flushed immediately with large amounts of lukewarm water<br>C) Flush eyes with aqueous ammonia<br>D) Apply saline solution to affected eyes<br>B) Chlorine must be flushed immediately with large amounts of lukewarm water (v.1 pg 377)<\/p>\n","protected":false},"excerpt":{"rendered":"<p>What is the methane content in a properly operation anaerobic digester? A) 30 to 35% by volumeB) 1 to 2% by volumeC) 65 to 70% by volumeD) 15 to 20% by volumeC) 65 to 70% by volume (v.2 pg 158) What will the addition of chlorine gas do to the pH of wastewater? A) Moderately [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[],"tags":[],"class_list":["post-110433","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/110433","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=110433"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/110433\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=110433"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=110433"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=110433"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}