Wastewater Treatment Plant Operations, Exams of Nursing

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WASTEWATER D LICENSE EXAM 2024 WITH ACCURATE SOLUTIONS How many PPB equals one PPM? - Precise Answer One thousand parts per billion equals one part per million If the bubbler system air supply line at the wet well is clogged, what will this cause the pump to do? - Precise Answer Pressure build up in the supply line would signal more water column then there really was, causing the pump to run longer than necessary, possibly not kick off and run continually If the bubbler system air supply line at the wet well has a hole in it above the water level, what will this cause the pump to do? - Precise Answer It would cause a low pressure reading showing a lower water level then there really is, or possible not even kicking on the pump What is the best way to keep within the operating budget? - Precise Answer keep list of purchases and expenses to date during fiscal year comparisons should be made with budget allocations to avoid excess purchases review purchases monthly and compare to budget If a diaphragm pump has 2 check valves open, what will the pump do? - Precise Answer It would not pump properly because 1 check valve should be shut while the other is open A suction lift pump on the inlet side normally reads 2in of mercury on the psi vacuum gauge but not reads 3in of mercury. What is the problem with the pump? - Precise Answer A higher vacuum than normal may indicate a partially plugged or restricted suction line. A lower vacuum may indicate a higher wet well level or a worn pump impeller or wearing rings. One mg per L equals how many pounds per 1 MG? - Precise Answer 8.34 What is the proper way to put packing in a pump? - Precise Answer cut the packing rope about 45 degree angle, place around shaft, be sure to offset/stagger the next joint from the previous How many drips of water should you have coming out of a packing seal? - Precise Answer no drip on a mechanical seal How many drips of water should you have coming out of a packing seal? 2 - Precise Answer what the operation and maintenance manual recommends A one horsepower motor that runs on 110 volts using 10 amps has what efficiency? - Precise Answer most motors run from 80-95% efficiency A motor that has 440 volt supply is usually what phase of power? - Precise Answer 3 phase aging and maturing of a body of water - Precise Answer eutrophication eutrophication - Precise Answer aging and maturing of a body of water If the effluent from a treatment facility contained 5mg/L of BOD, what effect would this have on the receiving stream? - Precise Answer little effect If you are doing a test and add one drop of chemical at a time, what is this method called? - Precise Answer titration If doing a winkler or azide method after adding the first 2 chemicals and the contents of the bottle turn white, what does this mean? - Precise Answer no oxygen left in bottle, it has all been consumed How far from a well should a sewer main be? - Precise Answer 300 feet a connection between a potable water system and a nonpotable water supply - Precise Answer cross connection a disease causing bacteria - Precise Answer pathogenic What diseases are considered to be waterborne? - Precise Answer Giardia and Cryptosporidium Typhoid, Hepatitis, Cholera What are the 3 main components in fertilizer that are in sludge? - Precise Answer nitrogen, potassium, phosphorus application of the various soil and plant sciences to soil management and crop production, scientific agriculture - Precise Answer Agronomy If the filter fecal test is run, what color would the fecal coliform show up as? - Precise Answer blue What is another name for non-filterable solids? - Precise Answer suspended solids If you switch any lead on a three phase motor, what is the result on the motor rotation? - Precise Answer it will reverse rotation What type of plant has these steps: MLSS in aeration, MLSS no aeration, MLSS in aeration? - Precise Answer step feed aeration the electromotive force (EMF) and is the electrical pressure available to cause a flow of current (amperage) when an electrical current is closed - Precise Answer voltage Where is the appropriate place to store a self contained breathing apparatus (SCBA)? - Precise Answer an approved casing hanging outside a chlorination room and unlocked How do you measure the amount of CL2 available in cylinders? - Precise Answer the cylinders are on scales, you determine the beginning weight and subtract the remaining balance to give you the available Cl2 What is the chemical symbol for chlorine? - Precise Answer Cl Two pumps are parallel to each other. Each one produces 300 gpm with 100 ft head. What would be the combined gpm? - Precise Answer over 300 gpm but less than 600gpm What is the purpose of thickening sludge? - Precise Answer to make it economically feasible What is the significant problem of having scum on the top of a pond? - Precise Answer it prevents sunlight from penetrating the algae How far should a sewer line be from a water main? - Precise Answer 50' separation or 10' horizontal and 18'' separation of sewer lines to water lines when they cross or meet at joints What is the best way to get rid of algae? - Precise Answer the first choice is chlorinating or alternative use is copper sulfate In what measurements is fecal reported? - Precise Answer the MPN in Colony Forming Units (CFU) in per 100 mL MPN - Precise Answer most probable number What is the purpose of disinfection? - Precise Answer to reduce pathogenic diseases for safer human contact stable bacteria that can either use dissolved molecular oxygen or oxygen obtained from food materials such as sulfate or nitrate ions - Precise Answer facultative bacteria What is neutral pH? - Precise Answer 7 What is the major problem with using UV disinfection? - Precise Answer the cost of the operation and bulbs are expensive What is not able to be removed by a treatment plant? - Precise Answer dissolved solids A sudden change in _________ of 10-20 mg/L may indicate a problem is developing in a pond and a warning that the pH will rise in 2 to 3 days? - Precise Answer alkalinity waste material which comes mainly from animal or plant sources - Precise Answer organics Hydrogen sulfide gas is noticeable by what characteristics? - Precise Answer rotten odor smell, 2-15 minutes at .01% impairs sense of smell and is near to the ground What is the minimum DO for fish to survive? - Precise Answer 5 to 7 parts per million or mg/L What book do you use to do lab tests? - Precise Answer standard methods What is the purpose of riprap? - Precise Answer prevention of emergent weeds and levee maintenance and repair and to prevent erosion a plate put between two flanges with a hole in the middle used to measure the rate of air flow through the pipes - Precise Answer orifice What is another name for total suspended solids? - Precise Answer non filterable solids How do you check for a chlorine leak? - Precise Answer tie a rag on a stick, dip the rag in a strong ammonia solution and hold the rag near hoses, fittings, and suspected leakage points. It will emit a white gas if there is a leak What is the maximum dry tons allowed to be applied in one year? - Precise Answer 2 dry tons per acre How much heavier is chlorine compared to air? - Precise Answer 2.5 times heavier What is the temperature of an incubator? - Precise Answer 20 degrees celsius. This is the temperature in which you run the BOD tests How often do you need to renew your license? - Precise Answer 3 years and 30 credit hours for renewal Wastewater is what percentage of water? - Precise Answer 99.9% What is an Imhoff cone? - Precise Answer used to measure settleable solids measured in mL/L What is the mandatory years for keeping records for NPDES? - Precise Answer 5 years What regulates the rules of hauling sludge? - Precise Answer 503 EPA Primary clarifier requires __ min-_._ hour detention time - Precise Answer 45 min- 1.5 hours What is the diameter of a manhole? - Precise Answer 48 inches or greater, min diameter of access is 22 inches ft per sec recommended on grit chambers? - Precise Answer 1ft per sec two conditions required to be septic - Precise Answer pH below 7, no DO _ foot depth in lagoons will allow sunlight to penetrate and produce algae. - Precise Answer 3 _ ft of freeboard at highest point of water - Precise Answer 2 fire hydrant needs to be ___ or possibly ___ ft away from a lagoon - Precise Answer 200, 300 _____________ pump motors can be damaged by overloading caused by operating the pump with too low discharge pressure. - Precise Answer centrifugal Samples for making lab tests should be ______________ of the sewage to be tested. - Precise Answer representative __ is measured in mg/L and the ______ cone is measured in mL/L - Precise Answer DO Imhoff ____ is added to water to increase the pH - Precise Answer lime If acid is spilled on the floor, immediately wash with _____ and neutralize with ______ ________________. - Precise Answer water sodium bicarbonate (baking soda) ______ in digesters occurs when sludge withdrawal is too fast - Precise Answer coning _______________ ponds are aerobic on top (oxygen present) and anaerobic (oxygen not present) on bottom - Precise Answer facultative theoretical time it would take the flow to completely displace the effective volume of the tank - Precise Answer detention time used to determine suspended solids' ability to separate from the liquid in the final clarifier - Precise Answer settleometer PPM (parts per million) equal __/_ - Precise Answer mg/L Pretreatment consists of 3 things - Precise Answer bar screen, comminutor, grit chamber the rate at which organisms use the oxygen in water or wastewater while stabilizing decomposable organic matter under aerobic conditions, measures the organic strength of wastes in water - Precise Answer biochemical oxygen demand (BOD) calculation which indicates the tendency of activated sludge solids to thicken or become concentrated during the sedimentation/thickening process - Precise Answer SVI-sludge volume index indicates the settleability of a sludge in a secondary clarifier of effluent the weight in grams of one mL of sldge after settling for 30 minutes - Precise Answer SDI- sludge density index, SDI=100/SVI Food to microorganism ratio, a measure of food provided to bacteria in an aeration tank - Precise Answer F/M ratio ______ in sewer lagoons serves the purpose to replenish DO in water - Precise Answer algae molecular (atmospheric) oygen dissolved in water or wastewater - Precise Answer dissolved oxygen (DO) What will cause the most wear on pump impellers? - Precise Answer grit sewage Emergent vegetation on the pond bottom, such as cattails, may be best controlled by keeping the depth greater than _ foot - Precise Answer 2 an opening between drinking water supply and the point of use in a wastewater treatment plant. This gap prevents the contamination of drinking water by backsiphonage because there is no way wastewater can reach the drinking water. Usually the gap is two times the diameter of the pipe - Precise Answer air gap gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing - Precise Answer flocculation clumping together of very fine particles caused by the use of chemicals. The chemicals neutralize the electrical charges of the fine particles, allowing them to come closer and form larger clumps - Precise Answer coagulation oxidation by aeration will remove what? - Precise Answer hydrogen sulfide What kind of impeller is on most pumps? - Precise Answer open On a centrifugal pump, water enters what? - Precise Answer eye of the impeller ___________ is caused by feeding the digester too fast - Precise Answer foaming __ psi is minimal amount on main water lines, a lesser amount will cause contamination throughout the whole system - Precise Answer 20 the two highest organic producers of high BOD - Precise Answer milk and blood not only a poisonous gas, but will also cause corrosion in the system - Precise Answer hydrogen sulfide gas the physical appearance of ______ sewers are dark brown or black in color, usually with a disagreeable odor - Precise Answer septic type of biological treatment - Precise Answer activated sludge Appreciable quantities of septic sludge "__________" to the surface of primary settling may indicate the sludge is not being pumped in sufficient quantities - Precise Answer burping Fish life is dependent on oxygen dissolved in water in which they live. The dissolved oxygen must be present in at least _ to _ parts per million - Precise Answer 5 to 7 An operator who is to clean a wet well in a lift station that is 20 feet deep should ___________ before entering - Precise Answer ventilate purpose of sewage treatment - Precise Answer to prepare sewage for safe disposal for receiving streams the brownish flocculent culture of organisms developed in an aeration tank under controlled conditions - Precise Answer activated sludge ___________ sedimentation is a physical process. __________ sedimentation is a biological process. ____________ is a chemical process. - Precise Answer primary secondary chlorination _____ in a sewage lagoon serves the purpose to replenish dissolved oxygen in water - Precise Answer algae Sludge applied to land, ___ feet from well, sinkhole, lake, or pond. ___ feet from a dwelling - Precise Answer 300 150 If one layer of packing were placed on top of another layer, what would possibly happen? - Precise Answer scaring of pump shaft How do you store a pH probe? - Precise Answer DI water during use and buffer solution when stored for a period of time Oxygen deficiency becomes a concern when the oxygen level in a confined space is less than? - Precise Answer 19.5% Which of the following provides safety information for potentially hazardous or toxic materials? - Precise Answer MSDS Which of the following potentially hazardous chemicals is a hydrocarbon and may be found in a manhole? - Precise Answer methane If your one ton chlorine cylinder is leaking what type of repair kit should you use? - Precise Answer B Large debris (sticks, rocks, etc), large floating solids, rags, strings, cloth, etc. are categorized as? - Precise Answer screenings The time it takes for a unit volume of wastewater to pass entirely through a system is called? - Precise Answer detention time Many times pumps are used to bring wastewater to the treatment plant. What types of pumps are commonly used to lift influent wastewater? - Precise Answer centrifugal After chlorine, what is the most common eff wastewater disinfection technique or agent used in the US today? - Precise Answer UV radiation What is the standard used to perform a winkler method dissolved oxygen analysis? - Precise Answer .025 N sodium thiosulfate Compacted and hardened sludge in a hopper may be caused by: - Precise Answer excessive quantities of grit in the sludge too infrequent pumping What is the vertical distance between the elevation of the free water surface at the suction and that of the free water surface discharge of a pump called? - Precise Answer static head Which of the following is a type of positive displacement pump? a. axial b. turbine c. piston d. centrifugal - Precise Answer piston Which pair of parameters is typically used to adjust chlorine feed rates? a. chlorine supply and temperature b. sulfur dioxide supply and chlorine supply c. sulfur dioxide supply and flow rate d. chlorine residual and wastewater flow - Precise Answer d. chlorine residual and wastewater flow Chlorine gas is a? - Precise Answer yellowish green gas 2.5 times heavier than air The formation and collapse of gas pockets or bubbles on the blade of a centrifugal pump's impeller is known as what? - Precise Answer cavitation What is your first course of action if you see a slow constant drip from a pump shaft with a packing seal? - Precise Answer make no adjustment When planning to work on or near electrical equipment, be sure to always... - Precise Answer lock and tag out the equipment Which of the following indicates the impeller of a centrifugal pump may be worn or damaged? a. pump is delivering too much flow b. pump is very cold c. impeller speed is too low d. pump is not delivering the design flow - Precise Answer d. pump is not delivering the design flow You have just rewired the motor of a centrifugal pump. The pump is now running but generating little pressure and flow. What is the most likely cause? - Precise Answer wrong direction of impeller rotation from improper wiring When performing your own lab analysis, your testing methods must conform to? - Precise Answer EPA and standard methods What provides the basis for federal regulation of wastewater treatment in the US? - Precise Answer Clean Water Act Water seal connections to wastewater pumps should not connect directly to the city water supply because: - Precise Answer wastewater may be drawn back into the water system As a manager, how will developing good public relations assist your facility? - Precise Answer it will sustain public support for your facility By law, operational records for your lab and facility must be retained for? - Precise Answer 3 years What is the primary function of the wastewater treatment facility operator? - Precise Answer to maintain the requirements set forth in the plant's NPDES permit When organic wastes are discharged to receiving waters, oxygen is depleted by... - Precise Answer bacteria Three diseases potentially carried by wastewater - Precise Answer typhoid fever, dysentery, cholera Centrifugal pump parts include: a. diaphragm Why is a check valve used in conjunction with centrifugal pumps? - Precise Answer to prevent wastewater in the discharge line from flowing back through the pump Which type of test is typically never performed on wastewater influent? - Precise Answer fecal coliform Chlorine is primarily used to... - Precise Answer disinfect The media in a trickling filter is usually placed... - Precise Answer on a tile underdrain system The media of a trickling filter is made of what kind of material? - Precise Answer the media can be synthetic and or natural resources like rock The rotational speed at which a trickling filter distributor arm moves is normally dependent upon what? - Precise Answer the setting of the motor speed on the arm proportional to the flow coming into the plant water that enter the collection system though breaks and openings not consistent with a domestic service is called... - Precise Answer inflow and infiltration What is the ideal velocity of flow through a sanitary sewer main? - Precise Answer 2 ft/sec A grit channel is designed to? - Precise Answer decrease the flow to 1 ft/sec to allow the grit to separate from the flow so it can be removed How long are BOD samples incubated? - Precise Answer 5 days The most important thing to determine the media for a trickling filter is... - Precise Answer media size for maximum surface area The film mass that grows on a trickling filter media is called... - Precise Answer zooglial The ceramic holder used in TSS testing is called the... - Precise Answer gooch crucible In the course of performing a winkler's titration for DO, a white floc forms after the addition of the iodide and sulfide reagents. The white floc indicates? - Precise Answer no DO is present in the sample The dissolved oxygen content of distilled water at sea level and room temp should be approximately how many mg/L? - Precise Answer 8.0mg/L Who is ultimately responsible for compliance with the condition of the NPDES permit? - Precise Answer permitee/city Name 3 elements of the hydrological cycle - Precise Answer evaporation, transpiration, precipitation, percolation, run off, infiltration How many hours of training are required to maintain a state of Missouri wastewater operator certification? - Precise Answer 30 in 3 years What are the impacts of untreated wastewater on the environment? - Precise Answer diseases, pollution, fish kills wildlife protection, water conservation, recreation, drinking water Name 2 pollutants found in wastewater - Precise Answer oil and grease What is the process of wastewater treatment? - Precise Answer biological, chemical, physical process to reduce pollutants in discharge of water preliminary treatment, primary treatment, secondary treatment disinfection name 3 diseases that can be caused by contact with wastewater - Precise Answer typhoid, cholera, dysentery What are the 3 phases water can be found in? - Precise Answer liquid, solid, vapor What are the three types of wastewater? - Precise Answer domestic, industial, and stormwater How does temperature affect settling in a clarifier? - Precise Answer The colder it is, the longer solids take to settle What are the 4 steps of mechanical treatment? - Precise Answer preliminary- headworks primary-sedimentation and floatation secondary-filters, RBC, lagoon, activated sludge tertiary-uv, chemical An operator conducts a test where the 30 min settling volute is multiplied by 1000 and the result divided by the mixed liquor suspended solids value. what is this test called? - Precise Answer settleability svi (sludge volume index) Filamentous bacteria can become a problem due to this oxygen condition: - Precise Answer low DO This aerobic process is where bacteria convert ammonia to nitrite and nitrate? - Precise Answer nitrification This device is used to remove rags, roots, and debris to keep it from entering the treatment facility? - Precise Answer bar screen anaerobic bacteria cannot survive in this type of environment - Precise Answer environment that contains oxygen What is the incubation time and temperature for the analysis of BOD? - Precise Answer 5 days at 20 degrees C What is the oven temp for TSS analysis? - Precise Answer 103-105 What color are the fecal colonies on the membrane filtration method of bacterial analysis? - Precise Answer blue When reading a graduated cylinder or pipette, you read the liquid level at _________________ to determine the correct value. - Precise Answer bottom of meniscus Typically, to be a valid BOD analysis, the sample must have an uptake of _ mg/L and must have _ mg/L remaining. - Precise Answer 2, 1 What is the max hold time for a wastewater bacterial sample? - Precise Answer 8 hours A properly operating primary lagoon cell will remove this percentage of BOD? - Precise Answer 80% Coming in on a Monday, the operator notices the lagoon is gray, this could indicate what condition is occurring? - Precise Answer septic or overloading These chemicals may be used to increase the oxygen in a lagoon with low dissolved oxygen? - Precise Answer ammonium nitrate, sodium nitrate, silver nitrate If an operator allows duckweed to cover a lagoon cell, what is the most likely thing that will happen? - Precise Answer stops sunlight penetration and hinders surface aeration, reducing lagoon DO What are 2 common problems associated with an anaerobic digester that is not working correctly? - Precise Answer foaming, formation of struvite You can find info associated with the requirements for biosolids in this part of the operating permit - Precise Answer standard conditions part III or 3 The sludge removed from facilities with a population equivalent less than 150 is considered this material? - Precise Answer septage The liquid that is removed from a digester when the solids are settled is called? - Precise Answer supernatant This digestion process, if done properly, will produce methane gas? - Precise Answer anaerobic The reasons we digest sludge: 3 - Precise Answer reuse, reduce volatile organics, reduce pathogens