TEXAS WASTEWATER CLASS C EXAM 2024-2025, Exams of Nursing

Download TEXAS WASTEWATER CLASS C EXAM 2024-2025 and more Exams Nursing in PDF only on Docsity! 1 | P a g e TEXAS WASTEWATER CLASS C EXAM 2024-2025 WITH ACTUAL CORRECT QUESTIONS AND VERIFIED DETAILED ANSWERS |FREQUENTLY TESTED QUESTIONS AND SOLUTIONS |ALREADY GRADED A+|NEWEST|GUARANTEED PASS |LATEST UPDATE What device(s) can be used as an emergency shut-off for the drive unit of a circular clarifier? Shear Pins You are the operator-on-duty. The alarm for the fire detector in the Belt Filter Press Control Room goes off. What type of fire extinguisher would you take to respond to this alarm? Class C When working in an area with two or more floor coverings (for example, grating and checker-plate), be sure that they are always _____. Secured together When working in confined spaces where flammable gases may be present, use only toolsmade of A non sparking alloy A treatment plant should have a valve exercise program in which all plant valves are exercised (opened and closed) Once a year Immediate first aid for burns is to? Flood with cold water Recommended personal hygiene practices to minimize the risk of being infected by wastewater pathogens include 2 | P a g e Changing out of your work clothes and showering before leaving work What is the best protection against the risk of exposure to infections and disease at a wastewater plant? Personal Hygenie Regarding fire extinguisher training in the workplace. The employer must provide what? A written and practiced emergency action plan. The combination of methane and which other gas can be very combustible? Oxygen In what location of the sewer manhole would methane gas be found? At the top Which type of fire is safe for a pressurized water extinguisher or water hose to be used on? Brush Mixing dry granular chlorine (HTH) with petroleum products can cause which of the following? Create a fire or explosive condition The fusible plugs found on a 150lb cylinders and one-ton chlorinecontainers are designed to melt at what temperature range? 158-165 degrees Fahrenheit In the event of a large leak of chlorine is occurring, what is the first action the operator should take? Immediately notify local fire and police departments A Class C type fire involves? Electrical equipment A common fire extinguisher is AB or ABC type. What is the media contained inside these fire extinguishers? Dry Powder This toxic gas impairs one's sense of smell rapidly at high concentrations as it paralyses the respiratory organs. At lower concentrations it has a rotten egg odor. Hydrogen Sulfide Gas Coliform bacteria are: More resistant to chlorination than pathogenic bacteria Coliform bacteria are: Indicators 5 | P a g e large solids Which of the following indicates that the impeller of a centrifugal pump may be worn or damaged? Pump is not delivering the design flow How often should inactive valves be exercised? Quarterly A positive-displacement sludge pump should never be placed into operation With the discharge valve closed A device that causes the wastewater in a vertical riser pipe to rise to an outlet using compressed air is called an Air lift pump If packing is not maintained properly, If packing is not maintained properly, If bearings on a centrifugal pump are running hot, over- or under-lubrication should be checked. If lubrication is satisfactory, the next preventative maintenance check would be to Inspect the alignment of the pump and motor A water-filled mechanical pump seal not only helps to prevent leaks but also Acts as a lubricant for the pump shaft and keeps gritty material from entering the packing box The formation and collapse of gas pockets or bubbles when water reaches boiling point on the blade of a centrifugal pump's impeller are known as what? Cavitation Which of the following is a type of positive-displacement pump? Gear If the pump bearings on horizontal pumps are over-lubricated, the most important effect is that the extra lubricant: This may cause overheating and possible failure of the bearings The primary cause of motor failure is: Moisture, and Vibration overload A water seal on a pump serves a dual purpose. It acts as a lubricant and it keeps gritty material from entering the packing box What could cause a centrifugal above-ground trash pump to be noisy? 6 | P a g e Debris caught in impeller housing. Electrical current is measured as Amperes What can cause a centrifugal pump to get very hot and sound like it's trying to pump gravel or rocks? Cavitation Which type of packing found on centrifugal pumps should not leak? Mechanical Seals What is an inexpensive, replaceable part on a centrifugal pump that allows itself to become worn? Wear Rings What type of horsepower accounts for the efficiency of a pump? Brake Horsepower The work required to move 33,000 ft/lbs per minute is equal to? 1 HP What is a rule of thumb regarding seal water type rope packings? Seal water should leak from the packing at about one drip per second. Which type of switch is supplied as a "normally open" or "normally closed" model? Float Switches What is a typical application for a centrifugal pump? Drain sump pump and reuse water How could severe damage to a positive displacement pump or its piping occur? Starting the pump against a closed discharge valve The majority of pumps used in wastewater treatment are classified as? Positive displacement and centrifugal In a centrifugal pump, the volute is the? The body of the pump What is a rule of thumb regarding pump packing? Never put rings of new packing over the old Which statement below best represents the proper removal and replacement of rope-type packing in a centrifugal pump? 7 | P a g e Always install new packing material and stagger the packing joints Methane Anaerobic is odorless. True One method used to minimize odor generation in sewer lines is to prevent solids deposition by designing a system with a high-flow velocity. What is the recommended design flow velocity to minimize odors? Greater than 2.0 ft/sec A "rotten egg" odor near a trickling filter generally indicates Anaerobic conditions within the filter Odor complaints are increasing at the WWTP. The operator finds most odor is coming from the primary clarifiers where bubbles and chunks are found on the tanks surface. What should be done to correct the problem? Increase the sludge withdrawal from the primary clarifiers. If sludge is not removed frequently enough from the primary clarifier, what could occur? If sludge is not removed frequently enough from the primary clarifier, what could occur? If a facility decides to use an alternative method of biosolids treatment that is not a part of the existing facility operating permit, and the process will be operating in a manner inconsistent with the permit, the facility should: Notify the state regulatory agency before using a new method and modify the operating permit if necessary. FDEP Chapter 62-600 FAC, Domestic WastewaterFacilities, states that all treatment plants shall be what? Fenced Chapter 62-601 FAC, Domestic Wastewater Treatment Plant Monitoring, states that on-site tests for _______________ can be performed Dissolved Oxygen, total residual chlorine, and pH According to FDEP Chapter 62-601 FAC, Domestic Wastewater Treatment Plant Monitoring, discharge monitoring reports (DMRs) for the previous month must be submitted to the department by which day of the following month? the 28th FDEP Chapter 62-620 FAC, Wastewater Facility Permitting, requires applications for permit renewal to be submitted to the department how many days before the expiration of the existing permit? 180 days According to FDEP Chapter 62-600.440 (4)(b) FAC, basic-level disinfection is described as? 10 | P a g e Disc type filters use what type of media? Cloth or steel mesh Plant problem: The operator returns to the treatment facility and finds the power to the RBC units has been off for an extended period of time. A generator is started and power is restored to the RBCs. The operator notices the exposed biomass has dried out due to the extended off time, however, the submerged media growth is thick and heavy. What should the operator do before restarting theRBC unit? Remove excess media growth to prevent an unbalanced condition upon start-up. With regard to troubleshooting RBCs, choose the correct statement: The media surface is visible, so observing biofilm thickness, and condition will help reveal clues to solve the problems. The main action of a mixed media filter is: Straining A ________ is used to measure the weight of samples that may be on filter paper, in evaporating dishes, etc. Analytical Balance As per FDEP administrative code, how often must secondary devices used to report total daily plant flow to be calibrated, or verified for accuracy? Annually What are two types of Primary flow measurement devices? Open channel, and closed conduit If an operator is uncertain how to perform an analytical test, he or she would refer to a book called: Standard methods for the examination of water and wastewater Which statement below is correct regarding grab samples? It is a single sample of wastewater taken at one instant of time from one location Solids that remain in suspension in wastewater and will not pass through a filter are called: Total Suspended Solids (TSS) Which type of sample, where the sample volume or frequency of collection increases or decreases as the flow rate increases or decreases? A portion of a sample A flow-proportioned composite sample A composite sample is 11 | P a g e A series of samples collected at intervals, usually in proportion to the existing flow, and then combined to form a sample representative of flow over a period of time, typically 24 hours An aliquot is: A portion of a sample Measuring the pH of a sample must be performed within ________ after collection. 15 minutes _________ is how close the results of replicate measurements agree. Precision (rePlicate) _______ is how closely the measured value agrees with an accepted reference value. Accuracy (Agree) The FDEP permitted effluent range for pH is between 6 and 8.5 A pH of 12 is _________ times more basic than apH of 7 100,000 A primary clarifier that is operating efficiently should be removing how much BOD? 25-40% Septic wastewater can cause strong odors and also __Corrosion___. What could be the cause of short-circuiting through the primary clarifiers? Uneven or unlevel weirs To determine detention time, you need to know the volume of the tank and what other piece of data? Flow rate Basic data used to determine primary sludge pumping rates include experience, influent suspended solids, sludge total solids, and what other piece of information? Sludge blanket depth What could occur if the velocity is too high in some sections of the clarifier effluent weir than in other sections? Increased amounts of suspended solids could be carried out with the effluent What are designed to minimize the effects of hydraulic short-circuiting caused by density currents? Baffles 12 | P a g e What is the recommended minimum frequency of sludge blanket depth measurements? Once per day Operators should make certain that sludge blanket measurements are measured consistently at the same time each day or shift and which of the following? At the same location in the clarifier If there is excessive sedimentation in the inlet channel, what action should you take to solve the problem? Increase velocity or agitate with air or water Imhoff cones should be used to measure settleable solids for what length of time? 30 minutes Removing rags from the weirs and scum hopper is done as part of Preventative maintenance Advanced Wastewater Treatment (AWT) includes the removal of: Nitrogen According to the FDEP Ch 62-610.469, any utility that is practicing reuse of attached wastewater shall have: An approved cross connection control program According to the FDEP Ch 62-600.400 FAC, when using high-level disinfectant on reclaimed water, any one sample may not exceed how many fecal coliform units, per 100 ml? 25 CFU Where is the location for collecting the TSS sample for meeting the 5mg/L TSS permitted limit when the flow is going to a reclaimed water reuse system? After filtration but before final disinfection. What is the process called that uses large amounts of chemicals in the plant influent to precipitate colloidal solids and phosphorus in the primary clarifier? Chemically enhanced primary treatment Preliminary treatment of wastewater does not include Sludge sedimentation Following coagulation, the next step in a physical-chemical treatment is called Flocculation The primary function of secondary clarifiers is to 15 | P a g e What is the advantage of using plastic media in place of traditional rock type media in the trickling filter? Higher surface area for increased biofilm growth. What powers the rotation of the trickling filters rotary distributor arm? A hydraulic force Which component of the trickling filter assembly rests on the large bearings that are sealed from the influent wastewater? The rotor Problems that are associated with trickling filters include: Problems that are associated with trickling filters include: Which of the following is an example of an attached growth process treatment? Rock media trickling filter The optimum wavelength for UV light for the inactivation of bacteria and pathogens is 253.7nm What is a by-product of ozone when used as a disinfectant? Oxygen According to FDEP ch 62-600.440 FAC, the minimum chlorine residual to meet basic level disinfection is. 1.0 mg/L As the effluent PH increases, the effectiveness of chlorine as a disinfectant. Decreases Which of the following is a parameter to measure when using a UV light system for effluent disinfection? UV transmittance, % What are two main acids formed when using chlorine as a disinfectant? Hypochlorous and Hydrochloric acid What is the disadvantage of using ozone as a disinfectant? Ozone must be generated on site and is unstable Commercially available sodium hypochlorite, also known as industrial bleach, contains what percent of chlorine? 10-15% 16 | P a g e If a gas chlorination system using a 150-pound chlorine cylinder is trying to feed more than 40 lbs/day through a vacuum-type chlorinator, what can happen? Chlorine icing could occur, reducing gas flow. What is the normal range of chlorine gas pressure found within a full 150-pound cylinder of chlorine? 20 to 30 psi What is the normal pressure range of chlorine into the gas chlorinationfeed system? 20-40 PSI The addition of sodium hypochlorite and calcium hypochlorite has what effect on effluent PH? Effluent PH will increase Which of the following is acid formed when chlorine gas is dissolved into a water supply? Hypochlorous acid Which is the correct effluent disinfection requirement for basic level disinfection, as per FDEP Ch 62- 600.440 FAC? No less than 0.5 mg/L total residual chlorine for at 15 minutes at peak hourly flow What are two common methods to measure total chlorine residual? DPD colorimetric and amperometric titration Which statement below would be correct regarding the effluent UVT and turbidity with respect to UV light efficiency? The lower the turbidity and higher the UVT, the better the inactivation Which part of the gas chlorination system is used to measure the rate of flow of chlorine gas? The rotometer Which of the following is a property of chlorine? Gas chlorine fed into effluent will tend to lower the PH of water (which can be used for disinfection) may be mechanically produced by photochemical or electrical methods resembling the natural processes. Ozone Name the two forms of hypochlorite (in alphabetical order) used for disinfection: Calciumhypochlorite, Sodium hypochlorite The two qualities in a final effluent that most affect the performance of an ultraviolet disinfection system are UV transmission and ____________. 17 | P a g e Suspended solids After chlorine, what is the most common effluent wastewater disinfection technique or agent used in the US today? Ultraviolet radiation Plant effluent coliform count fails to meet the required standards for disinfection. The chlorine residual is normal. Disinfectant supplies are not a problem. What is the most probable cause? Contact time is too short If solids have settled in the chlorine contact chamber, what would you expect to be happening to the effluent chlorine residual? The effluent chlorine residual concentration will vary greatly Preventative maintenance and repair on chlorine disinfection equipment require which of the following: Using only manufacturer approved parts This form of disinfection produces no disinfection by-products: UV light According to Chapter 62-600.440 (5) (f) FAC, regarding high level disinfection, any one sample shall not exceed how many fecal coliform values over a 30-day period? 25 The operator of the small wastewater treatment plant uses sodium hypochlorite (bleach) and is experiencing poor fecal coliform kills. What could be the cause of the problem at the plant? The bleach strength has weakened over time The addition of sodium hypochlorite and calcium hypochlorite has what effect on effluent pH? Effluent PH will increase How is sludge age determined? MCRT What is a sludge blanket? Layer of solids on the bottom of the clarifier How much oxygen depletion is needed for a valid BOD test? 2 mg/L The highest removal efficiencies in an RBC will occur with: Warm weather 20 | P a g e Ultraviolet rays What unit is used to quantify fecal coliform results? MPN (Most Probable Number) Which chemical can be used in treating water for phosphorus removal? Ferrous sulfate Typically the presence of light, stiff, and billowy white foam on the surface of an aeration tank is an indicator of ________. What action should you take to correct this problem? High F:M ratio, you should decrease wasting The utility you work for is preparing to implement a new staffing plan. Which of the following is most critical for the successful implementation of this plan? Communicate the plan to the staff in advance? Gravity thickeners are most similar to? Clarifier Which of the following tests is a good way to measure the biological activity and aeration within a biological reactor? SOUR The precipitation of magnesium ammonium phosphate throughout an anaerobic digester system is referred to as: Scaling Which of the following is most likely to reduce the effectiveness of UV treatment? Total Suspended Solids (TSS) The addition of chlorine to effluent until all the chlorine demand is removed and a residual is generated, is referred to as: Breakpoint chlorination If unable to analyze immediately, it is recommended to begin a BOD analysis within at least ____ hours of collection: 6 A 1% solution is equal to: 10,000 mg/L Total Kjeldahl Nitrogen (TKN) refers to: Organic nitrogen and ammonia nitrogen 21 | P a g e If there is a large increase of influent plant solids, you may need to increase the ________in the aeration tank. Mixed Liquor Volatile Suspended Solids (MLVSS) Absorption The process organisms use to transport organic material to their cells Acid pH less than 7 Alkaline pH greater than 7 Acid forming bacteria Anaerobic bacteria that produce volatile acids as waste products Activated sludge process A biological wastewater treatment process in which a mixture of wastewater and activated sludge is agitated and aerated. Aeration detention time The time expressed in hours, which mixed liquor is subjected to aeration in an aeration tank while undergoing the activated sludge process Aeration rate The amount of air supplied to the mixed liquor measured in CFM Aerobic A condition in which "free" or dissolved oxygen is present in water Anaerobic A condition in which "free" or dissolved oxygen nor nitrate/nitrite are not present in water Anoxic The anaerobic aquatic environment that lacks free dissolved oxygen, but does have available oxygen in the form of oxidized nitrogen N03 Aerobic digestion Sludge stabilization using aerobic microorganisms; free oxygen must be available Anaerobic digestion 22 | P a g e Sludge stabilization using anaerobic microorganisms that grow only in environments that lack free oxygen and nitrate Ammonia Breakdown of proteins to form NH3 Ashing In the activated sludge process, small particles of sludge which look like ash are on the surface of the secondary clarifier. Autotroph An organism that can use sunlight or inorganic chemicals as energy sources Heterotroph Organisms that consume and decompose organic matter as an energy source Baffle A structure that directs the wastewater flow or retains floating material Batch Reactor A reactor in which flow is neither entering nor leaving on a continuous basis Billowing Sludge Indicates potential for solids washout in the secondary clarifier. Can be identified by localized clouds of sludge solids rising near the surface Biochemical Oxygen Demand (BOD) A measurement of the amount of oxygen required by the microorganisms to metabolize or digest the organic material in wastewater Biofilm The layer of microorganisms on attached growth media Biological filter A bed of sand, gravel, or broken stone, which wastewater flows or trickles over Biological filtration The process of passing a liquid through a biological filter, thus permitting contact with zoogleal films attached to the media that adsorb and absorb fine suspended solids, colloidal, and dissolved solids. Biological Nutrient Removal (BNR) Treatment technologies that utilize the natural behavior of bacteria to oxidize and remove nitrogen and or phosphorus 25 | P a g e A preliminary treatment device in which influent wastewater is slowed down sufficiently to allow the grit to settle while keeping organic material suspended in flow Head An expression of the pressure or energy of fluids in terms of the height of a vertical column of water Head loss Energy lost from flowing fluids due to friction and turbulence Hydraulic loading The volume of wastewater applied to a unit in a given time Hydoroxide Ion (OH-) must be present to have a pH greater than 7 Hypochlorous acid A compound (HOCl) formed from the reaction of chlorine and water Indicator organisms Microorganisms whose presence indicates the possible presence of pathogenic organisms Organic Matter High-energy carbon compounds usually from plant or animal sources Inorganic matter Material such as sand, salt, iron, calcium Jar test Tests used to determine dosage rates for chemicals such as flocculants Luxury Uptake The ability of poly-P bacteria to accumulate more phosphorus than they would normally need Manometer Used to measure pressure Mean Cell Residence Time (MCRT) Average period that a cell is held in the activated sludge process. Also known as the solids retention time. Mesophilic Temperature between 80-90 F 26 | P a g e Thermophilic Temperature between 120-135 F Methane Flammable gas produced by the decomposition of organic matter Methane-forming bacteria Bacteria, in anaerobic digestion, use volatile acids, produced by another group of bacteria to produce methane gas Mixed Liquor The mixture of wastewater and return activated sludge in the aeration tank Nitrosomonas Bacteria that convert ammonium to nitrite Nitrobacter Bacteria that convert nitrite to nitrate Parshall Flume A specially shaped portion of an open channel with a constricted area to measure flow rate Peak Load The maximum amount of flow rate to wastewater treatment plant Plug Flow Reactor Idealized continuous flow reactor in which fluid particles are discharged in the same order in which they entered Preventative maintenance scheduled lubrication, inspection, and adjuments to equipment Rotameter A flow measuring device utilizing a tapered tube and a float Rotating Biological Reactor (RBC) An attached growth process in which media is rotated through wastewater on a shaft Scum Blanket In anaerobic digestion, a layer of floatable solids that accumulate on the surface Secondary Treatment 27 | P a g e The phase in which dissolved and suspended material is converted into a form more readily separable from the wastewater Septic A condition produced by the growth of anaerobic organisms. The water turns black, has foul odors, and heavy oxygen demand Settlebale solids the matter that will not stay suspended Concentration (SSC) Activated sludge process control, SSC, is determined using the results from the settleometer test (usually 30-minutes) and centrifuge spin test Shear pin A piece of metal that breaks to prevent damage to equipment used in high torque situations Shock Load The arrival of waste that is toxic to organisms in sufficient quantity or strength. Organic or hydraulic overloads can also cause shock Sloughings The material washed off the trickling filter media Sludge The settable solids separated from the liquid during clarification Sludge Age In the activated sludge process, a measure of the length of time a particle of suspended solids has been undergoing aeration. expressed in days Sludge blanket The layer of sludge that forms at the bottom of clarifiers Sludge bulking Poor settling due to low density floc in the activated sludge Sludge Volume Index (SVI) A ratio of the mixed liquor settleability to the MLSS concentration. Indicates the ability of the particular sludge to settle Solids Inventory The pounds of MLSS in the aeration tank and secondary clarifier