Wastewater Treatment Operator Certification Test #2 100% VERIFIED ANSWERS 2024/2025 CORR, Exams of Health sciences

Download Wastewater Treatment Operator Certification Test #2 100% VERIFIED ANSWERS 2024/2025 CORR and more Exams Health sciences in PDF only on Docsity! Wastewater Treatment Operator Certification Test #2 100% VERIFIED ANSWERS 2024/2025 CORRECT STUDY SET Study What is the typical BOD removal efficiency in a primary clarifier? A) 10 to 15% B) 40 to 60% C) 20 to 50% D) 95 to 99% C) 20 to 50% (v.1 pg 129) What does the "F" in F/M ratio represent? A) The microorganism population in the aeration tank B) The amount of filamentous bacteria in the activated sludge process C) The MLVSS in the aeration tank D) The food for the microorganisms flowing into the aeration tank, in lbs/day D) The food for the microorganisms flowing into the aeration tank, in lbs/day (v.2 pg 58) Which of the following describes the appearance of healthy activated sludge? A) Thick, greasy, dark tan foam B) Brown with a moderate amount of crisp, white foam C) Clear liquid with clear foam D) Gray liquid with no foam B) Brown with a moderate amount of crisp, white foam What is used to control filamentous organisms? A) Polymer B) Sulfur Dioxide C) Coagulant D) Chlorine D) Chlorine (v.1 pg 399) What are commonly used to control chlorine feed rate for disinfection? A) BOD and MLVSS B) pH and temperature C) Flow and chlorine residual D) DO and TSS C) Flow and chlorine residual (v.1 pg 356) Which toxic gas is commonly found in septic wastewater and smells like rotten eggs? A) Hydrogen Sulfide B) Carbon monoxide C) Hydrogen D) Carbon Dioxide A) Hydrogen Sulfide (v.2 pg 299) What is the permissible exposure limit for chlorine gas vapor during a normal 8 hour workday and a 40 hour work week? A) 0.1 ppm B) 0.5 ppm A) Colloids B) TDS C) Pieces of wood, roots, rags, and other large debris D) COD C) Pieces of wood, roots, rags, and other large debris (v.1 pg 41) What happens when there is more food in the influent to the aeration tank? A) Less oxygen is required in the aeration tank B) More oxygen is required in the aeration tank C) Less organism activity takes place D) Less oxidation takes place B) More oxygen is required in the aeration tank (v.2 pg 19) What impact does temperature have on the reaction rate of microorganisms in wastewater? A) Reaction rate doubles with every 18 degree Fahrenheit increase in temperature until higher temperature inhibits biological activity B) Reaction rate decreases by 20% with every 10 degree Fahrenheit increase in temperature C) Reaction rate of microorganism is not impacted by temperature D) Reaction rate goes to zero A) Reaction rate doubles with every 18 degree Fahrenheit increase in temperature until higher What is commonly used to control the odor of hydrogen sulfide? A) Carbon Dioxide B) Methane C) Chlorine D) Hydrogen C) Chlorine (v.1 pg 398) What is used to determine the amount of microorganisms in the aeration tank? A) Mixed Liquor Suspended Solids (MLSS) B) Influent TSS C) BOD D) Mixed Liquor Volatile Suspended Solids (MLVSS) D) Mixed Liquor Volatile Suspended Solids (MLVSS) (v.2 pg 58) What could happen if the sludge line is isolated by closing the valves on each end for several days? A) It could result in water hammer B) Cavitation C) Gas production could increase the internal pressure and cause the line to fail D) The aerobic condition will cause Zoolgleal mass to grow in large numbers. C) Gas production could increase the internal pressure and cause the line to fail (v.2 pg 152) Which is true about chlorine gas? A) It is 2.5 times lighter than air B) it is 2.5 times heavier than air C) It is 1.5 times heavier than air D) It is 1.5 times lighter than air B) it is 2.5 times heavier than air (v.1 pg 375) Which of the following is typically treated by biological processes? A) Roots and rags B) Sand and eggshells C) Cinders D) Dissolved and non settable organic material D) Dissolved and non settable organic material (v.1 pg 46) Which document is a written record that accurately traces the custody of wastewater samples through all phases of a monitoring program? A) Wastewater Lab Analysis form B) NEPA C) Chain of Custody form D) Diagnostic form C) Chain of Custody form (v.2 pg 498) What could cause a sudden drop in pH of the influent? A) Acidic chemical in the influent B) A strong base was dumped into the collection system C) Ammonia from a factory was discharged into the sewer D) The influent contained sodium hydroxide A) Acidic chemical in the influent (v.2 pg 579) What is the recommended daily maintenance activity for a clarifier? A) Dewater the clarifier by draining the wastewater B) Repaint metal surfaces that have lost their protective coating C) Hose down walls, floor and equipment inside the clarifiers D) Inspect chains, sprockets, and flights. D) Inspect chains, sprockets, and flights (v.1 pg 118) Which of the following could be the cause of ponding in a trickling filter? A) Hydraulic loading is too low B) Clogging of distributor orifices C) Excessive organic loading D) Denitrification C) Excessive organic loading (v.1 pg 192) What could happen if the dissolved oxygen content in the aeration tank is too low? A) Pinpoint floc will develop B) Filamentous organisms could thrive and prevent the sludge sludge floc from settling properly in the secondary clarifier C) 6 hours D) 1.5 to 2 hours D) 1.5 to 2 hours (v.1 pg 43) If you are testing the pH of a wastewater sample, what is the maximum recommended holding time? A) 5 days B) It must be tested immediately C) 24 hours D) 36 hours B) It must be tested immediately (v.2 pg 502) What could cause short circuiting in a clarifier? A) Sludge composition B) Reduction in flowrate C) Uneven weir settings D) Broken sludge pump C) Uneven weir settings (v.1 pg 125) What could cause the slime growth on a rotating biological contactor to appear black? A) It could indicate solids or organic overloading B) High DO in the plant effluent C) Lack of BOD in the influent to the rotating biological contactor D) Low hydraulic loading A) It could indicate solids or organic overloading (v.1 pg 228) What is an air gap? A) A distance between blowers in an activated sludge system B) The vertical distance between the surface of wastewater and the top of basin C) Backflow prevention D) Type of aeration equipment C) Backflow prevention (v.1 pg 503) Which is true about chlorine demand? A) Chlorine demand= Chlorine residual + Chlorine dose B) Chlorine demand= Chlorine does x Chlorine residual C) Chlorine demand= Chlorine residual - Chlorine dose D) Chlorine demand= Chlorine dose - Chlorine residual D) Chlorine demand= Chlorine dose - Chlorine residual (v.1 pg 352) What is accomplished by the activated sludge process? A) Anaerobic bacteria use SO_4 to eat incoming volatile solids B) Remove soluble or finely divided suspended materials C) Anoxic microorganisms destroy incoming BOD D) Zoogleal breaks down influent organics B) Remove soluble or finely divided suspended materials (v.2 pg 16) What is the carbon dioxide content of a properly functioning anaerobic digester? A) 65 to 70% by volume B) 1 to 2% by volume C) 30 to 35% by volume D) 40 to 60% by volume C) 30 to 35% by volume (v.2 pg 158) Which of the following is a collection of individual samples obtained at regular intervals? A) Grab B) Culmination C) Comprehensive D) Composite D) Composite (v.2 pg 499) What is the most common piece of laboratory equipment, which is used mainly to mix chemicals and measure approximate volumes? A) Beaker B) Graduated cylinder C) Pipet D) Flask A) Beaker(v.2 pg 479) What are colloids? A) Solids that settle rapidly B) Dissolved solids C) Solids found in the grit channel D) Very small, finely divided solids that remain dispersed in a liquid for a long time D) Very small, finely divided solids that remain dispersed in a liquid for a long time (v.1 pg 22,144) What is the most common type of grit collector? A) Deflectors B) Weirs C) Chain driven scrapers called "flights" D) Parshall flume C) Chain driven scrapers called "flights" (v.1 pg 87) What is true about surface loading and detention time? A) They stay fairly constant throughout the day B) They are impacted by the influent BOD C) They are indirectly related to flow D) They are directly related to flow D) They are directly related to flow (v.1 pg 118) What is a MSDS? A) A federal law that is designed to protect the health and safety of workers B) A condition in which a persons nose is no longer able to detect odor from a chemical C) A document that contains important information about a chemical, such as safe exposure level, flammability rating, and first aid procedures D A publication written by the federal government that contains all regulations, including those that affect safety and the environment 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) How often should grit be removed from the grit channel? A) Weekly B) Monthly C) Bi-weekly D) Daily D) Daily (v.1 pg 87) What is the typical removal efficiency from bacteria in a primary clarifier? A) 0-5% B) 25-75% C) 5-10% D) 10-20% B) 25-75% (v.1 pg 129) What problem could most likely cause a centrifugal pump to discharge at a reduced rate? A) Damaged impeller B) Slight water leak at the packings C) Pumping against less resistance D) Seal water is dripping slowly A) Damaged impeller (v.1 pg 182) What is the two categories of coliform bacteria? A) Lactose and lauryl tryptose B) Primary and secondary C) Free swimming and stalked D) Total and Fecal D) Total and Fecal (v.2 pg 552) Which of the following is true about the extended aeration process? A) Wasting is not necessary to maintain proper control of the process B) It produces more waste than conventional activated sludge process C) It has low F/M ratio D) It has low MLSS concentration C) It has low F/M ratio (v.1 pg 257) What type of disinfection is gaining popularity, and expected to become a practical alternative to chlorination? A) Sulfur dioxide B) Ultraviolet (UV) disinfection C) Aqueous ammonia D) Caustic soda B) Ultraviolet (UV) disinfection (v.1 pg 303) Where is the proper sampling location for an effluent from a wastewater treatment plant? A) Next to the chlorinator equipment B) At the end of a solids handling facility C) Prior to discharge into receiving waters D) At the head of a chlorine contact chamber C) Prior to discharge into receiving waters What is true if the F/M ratio increases? A) Less DO is required B) Less BOD is available C) DO will not be affected by an increase in F/M ratio D) More DO is needed D) More DO is needed (v.2 pg 53) Who must be included in a hearing conservation program to prevent hearing loss? A) Employees whose normal noise exposure equals or exceeds 65 decibels B) Employees whose normal noise exposure equals or exceeds an 8 hour time weighted average of 85 decibels C) Employees whose normal noise exposure exceeds 45 decibels at any time D) Employees whose normal noise exposure exceeds and 8 hour time weighted average of 25 decibels B) Employees whose normal noise exposure equals or exceeds an 8 hour time weighted average of 85 decibels (v.2 pg 277) What is a major cause of repeated sludge bulk? A) High pH B) High DO C) High food to mircoorganism loading rates D) High nutrient concentration C) High food to mircoorganism loading rates (v.2 pg 71) How can the efficiency of a trickling filter be improved? A) Raise the distributor arm B) Reduce the size of the ventilation ports C) Decrease the amount of the filter media D) Add recirculation What causes primary effluent to become black and odorous? A) Excessive sludge pumping B) Oil leak from the sludge pump C) Crack in the launder D) Improper sludge removal from the clarifier D) Improper sludge removal from the clarifier (v.1 pg 123) What is a biomass? A) Bacteria that change ammonia into oxidized nitrogen B) Organisms that grow in a thread or filamentous form C) A mass of organic material consisting of living organisms that feed on the wastes in sewage D) Wastes such as sand, salt, and calcium that are present in the plant influent C) A mass of organic material consisting of living organisms that feed on the wastes in sewage (v.2 pg 816) What is the color of a pond that is operating properly? A) Brown B) Deep green color C) Clear D) Tan B) Deep green color (v.1 pg 309) What does healthy activated sludge smell like? A) Chlorine B) Raw sewage C) Rotten eggs D) Earthy D) Earthy Which law regulates wastewater discharge to receiving water? A) Wastewater Act B) Clean Water Act C) National Discharge Act D) Federal Effluent Act B) Clean Water Act