Wastewater Treatment: Operator Responsibilities and Treatment Processes, Exams of Nursing

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As an operator, you are responsible to your employer for maintaining an economical and efficient operating facility. - correct answer TRUE An operator has an obligation to the great numbers of people who rely on down stream water supplies and are totally dependent on the operator's competence and trust worthiness for their welfare - correct answer TRUE Today, the natural purification processes in rivers treat all the waste loads and keep rivers clean. - correct answer FALSE Operators are water quality protectors on the front line of the water pollution battle. - correct answer TRUE The main benefit of a successful wastewater treatment program is the protection of the public health. - correct answer TRUE Without adequate, reliable records of every phase of operation, the effectiveness of your operation has not been documented (recorded). - correct answer TRUE Your records showing a high-quality effluent will mean nothing to citizens visiting your plant unless your plant appears clean and well maintained and the effluent looks good. - correct answer TRUE Safety is never an operator responsibility. - correct answer FALSE Chief operators frequently have the responsibility of training new operators and must encourage all operators to work safely. - correct answer TRUE

The waste water treatment field is changing rapidly and operators, maintenance personnel, foremen, managers, instrumentation experts, and laboratory technicians are sorely needed. - correct answer TRUE What is a treatment plant operator? - correct answer The final and essential link in maintaining and protecting the aquatic environment upon which all life depends on. Why are wastewater treatment plants built? - correct answer To purify soiled water and prevent pollution. How should wastewater treatment plant operators consider their job? - correct answer As a water quality protector on the front line of the water pollution control battle. What is the primary objective of an operator operating a wastewater treatment plant? - correct answer To protect the receiving water quality by continuous and efficient plant performance. How can a well-guided tour for other operators help an operator? - correct answer May allow the other operators to suggest helpful solutions to operational problems. What types of employers might a wastewater treatment plant operator work for? - correct answer A city, sanitation district, or other public agency. A large industry that operates its own treatment plant. A private contractor retained to operate and maintain a municipal or industrial treatment plant. Why do wastewater treatment plant operators need continuous training? Due to - correct answer Advanced or improved equipment. Increasing budgets. Increasing instrumentation. More facility tours. New treatment techniques. Why should an operator be present or at least available during the construction period of a new plant? - correct answer To become familiar with the entire plant, including the equipment and machinery and their operation. Operators are in the field of public relations and must be able to explain the purpose and operation of their plant to which groups? - correct answer City council or directors of the plant. Civic organizations. Officials of regulatory agencies. Representatives of news media. School classes.

Which factors are contributing to the increasing need for trained wastewater treatment plant operators?

• correct answer More sophisticated treatment. Operator certification regulations. Population growth. Regulatory requirements. Retirement of many current operators. All organic materials have one thing in common --- they all contain basic minerals. - correct answer FALSE Most living creatures need oxygen to survive, including fish and other aquatic life. - correct answer TRUE Initial efforts to control human wastes evolved from the need to prevent the spread of diseases. - correct answer TRUE The bacteria that grow in the intestinal tract of diseased humans find the environment in the wastewater treatment plant or receiving waters favorable for their growth and reproduction. - correct answer TRUE One of the primary functions of a treatment plant is the removal of solids from wastewater. - correct answer TRUE Operators try to kill or inactivate pathogenic organisms by disinfection. - correct answer TRUE The weight of non-settleable solids may be calculated by subtracting the weight of dissolved and total solids from the weight of settleable solids. - correct answer TRUE The organic portion of the total solids can be very harmful to receiving waters. - correct answer TRUE Operators should use a standard method for the measurement and evaluation of floatable solids. - correct answer FALSE Nutrient cycles are very complex and involve chemical changes in living organisms. - correct answer TRUE What is the definition of pollution? - correct answer Any interference with the beneficial reuse of water.

What is organic waste? - correct answer Waste material that may come from animal or plant sources. What is inorganic waste? - correct answer Waste material such as sand, salt, iron, or calcium. What happens to fish in receiving waters when bacteria use the entire supply of oxygen from the stream faster than it can be replenished by natural diffusion from the atmosphere? - correct answer They die. The stabilization of a waste means which of the following? - correct answer To convert the waste to a form that resists change. Many serious outbreaks of communicable diseases have been traced to which problem? - correct answer Direct contamination of drinking water or food supplies. What is an operator's best defense against infections and diseases? - correct answer Good personal hygiene. What is the objection to treated wastewater as containing nutrients? - correct answer Nutrients are capable of encouraging excess algae and plant growth in receiving water. Why are floatable solids undesirable in the plant effluent? - correct answer The sight of floatable solids in receiving water indicates the presence of an adequately treated wastewater. Why are ammonia and hydrogen sulfide undesirable in receiving waters? - correct answer They are odorous gases. Substantial amounts of organic industrial waste come from which industries? - correct answer Dairy processing, meatpacking, tanning, vegetable and fruit packing. Waste discharge is may contain what types of toxic substances? - correct answer Cyanide, and heavy metals.

Which substances are objectionable in treated wastewater discharges? - correct answer Highly acidic or alkaline (basic) substances. Pathogenic organisms. Taste and odor producing substances. Toxic substances Weather any problems are caused by the discharge of treated wastewater in the receiving water depends on which factors? - correct answer Amount of flow in the receiving stream or volume of receiving lake that can be used for dilution. Quality of receiving water. Size of flow from the treatment plant. Type or degree of treatment. Uses of the receiving water. Why do operators need to know how to control nutrient cycles? - correct answer To control odors. To protect receiving waters. To treat waste. The length of time required for ways to reach your plant can affect treatment plant efficiency. - correct answer True. Ponds are frequently constructed in rural areas where there is sufficient available land. - correct answer True. The purpose of flow measuring devices is to treat waste. - correct answer False All primary clarifiers, no matter what their shape, must have a means for collecting the settled solids and the floating solids. - correct answer True. Both the trickling filter and the activated sludge treatment processes or anaerobic biological treatment processes. - correct answer True. The activated sludge process is a biological process and it serves the same function as a trickling filter or rotating biological contactor. - correct answer True. Incineration or burial of skimmings from the clarifiers will prevent treatment plant operational problems.

• correct answer True. Algae in ponds produce oxygen for the other organisms to use. - correct answer True.

Both industry and agriculture are discovering the treated effluent may be the most economical source of additional water. - correct answer True. Aerobic and anaerobic sludge digestion processes produce stabilized or digested solids that ultimately must be disposed of in the environment. - correct answer True. What is a sanitary sewer? - correct answer A pipe or conduit (sewer) intended to carry waste water or water-borne waste from homes, businesses, and industries to the treatment works. When are pump stations normally installed? - correct answer When low areas of land must be sewered or where pipe depth under the ground service becomes excessive. How can fluctuating flows from a large pump station be reduced? - correct answer By using variable speed pump or short pumping cycles. What is the purpose of flow measuring devices? - correct answer To measure and record the flow rates and volumes of wastewater treated by the plant. What is the purpose of pre aeriation? - correct answer To freshen the wastewater and to help remove oils and greases. Why is treated wastewater disinfectant before it is discharge to receiving waters? - correct answer To prevent the spread of diseases. Why are debris and trash usually removed from wastewater by a bar screen? - correct answer To protect equipment and reduce any interference with in-plant flow. Why are most sewer pipes laid at a slope steep enough to maintain a wastewater flow of two feet per second (fps) (0.6m/sec)? - correct answer To prevent grit from settling in the pipes. Why should grit be removed early in the plant treatment process? - correct answer Because grit is abrasive and will rapidly wear out pumps and other equipment.

The exact amount of BOD removal in a clarifier depends on which factor? - correct answer The amount of BOD contained in the settled material. What happens when the clear surface water of the primary tank flows over the effluent weir at a high velocity? - correct answer Particles settling to the bottom or those already on the bottom may be picked up and carried from the tank. How is oxygen provided for the organisms living in the biological slime that grows on the RBC media? - correct answer The atmosphere surrounding the media. What are the two major types of bacteria present in a digester? - correct answer Acid formers and gas formers. Why must the effluent from plants in some areas be dechlorinated or detoxified before discharge receiving water? - correct answer To protect aquatic life. What is disinfection? - correct answer A process designed to kill or inactivate pathogenic organisms. If hydrogen sulfide from the collection system reaches your plant, what impact would this have on the plant? - correct answer Concrete in the plant would be damaged. Odor problems could occur. The wastes could be more difficult to treat. Wwaste water enters a treatment plant, it usually flows through a series of pretreatment or liminary treatment processes including which processes? - correct answer Grit removal. Screening. Shredding. Why must operators know the quantity of waste water flow into a treatment plant? - correct answer To adjust aeriation rates. To adjust chlorination rates. To adjust pumping rates. To calculate loadings on treatment plant processes. To calculate treatment efficiency. What are the disadvantages of using a weir to measure waste water flows entering a plant? - correct answer A relatively dead water space occurs just upstream of the weir. As solids accumulate upstream of the weir, the flow reading may become incorrect. Odors and unsightliness - can result from an upstream dead space. Organic solids may settle out upstream of the weir.

Which flow measuring devices are used to measure waste water flows in pipelines? - correct answer Magnetic flow meters. Venturi meters. Why are digestion tanks mixed continuously? - correct answer To avoid the formation of thick scum blankets. To bring the food to the organisms. To provide a uniform temperature. Scum blankets in a digester above the supernatant consist of which items? - correct answer Grease. Hair. Plastics. Rubber goods. Soap. Advanced methods of waste treatment are used to reduce which items from wastewater? - correct answer Nutrient content. Why do regulatory agencies require the disinfection of plant effluent prior to discharge? - correct answer To kill or inactivate pathogenic organisms. To protect the receiving water that is used for a drinking water supply. To protect the receiving water that is used for swimming or waiting. How can solids removed from wastewater by pre treatment process be disposed of? - correct answer By dewatering and then directly burial in an approved sanitary landfill. By incineration with the remaining ash disposed of in a landfill. There are many potential safety hazards around a wastewater treatment plant. - correct answer True. Always wash your hands thoroughly before eating, smoking, or going home. - correct answer True. Stand on a slippery surface while taking material from a bar screen. - correct answer False. Strong's or sewer cleaning operations by maintenance crews make all the sudden surge of wastewater and debris and a resultant greater head loss through the screens. - correct answer True. The totalizer records the total volume of screenings removed by the plant. - correct answer True.

When starting up comminutors and barminutors, always observe the unit to verify that it sounds normal and appears to be operating properly. - correct answer True. When estimating the velocity in a grit channel using a stick or other float, the average velocity in the channel will be slightly higher than you estimate. - correct answer True. A little organic matter in the grit removed from a grit channel usually indicates that proper velocities are being maintained in the channel. - correct answer True. Treat an empty grit washer as a confined space and provide adequate ventilation - correct answer True. Advanced preparation for emergencies can save a lot of extra work and make it possible to keep your plant operating efficiently under unfavorable conditions. - correct answer True. Which problem is created by a treatment plant operating at reduced efficiency? - correct answer An increase in the pollution level of the effluent discharged into receiving water. What is the purpose of screens, racks, comminutors, and grit removal devices? - correct answer To remove rocks, large debris, and grit. Which injuries can a cure from pulling too hard when lifting inlet or outlet gates or pulling heavy, waterlogged debris from the racks? - correct answer Back injuries, hernias, and muscle strains. What should the operator do after broken equipment has been repaired and placed in service again? - correct answer Observe the unit for proper operation. The frequency of sharpening the cutting edges on the cutter of a barmminutor depends on which factor?

• correct answer The type and abrasiveness of the wastewater being treated. What is putrescible materia? - correct answer Material that will decompose under anaerobic conditions and produce nuisance odors.

Why should a grit channel be removed from service during the cleaning operation? - correct answer To prevent the grit from being washed into the downstream treatment processes. Why should grit disposed of by burial be quickly covered with soil? - correct answer To prevent odors and attracting flies and rats. Under what condition should the cyclone liner and screw conveyor of a cyclone grit separator be replaced? - correct answer When excessive wear prevents proper adjustments and the equipment no longer functions as intended. What is detritus? - correct answer The heavy material present in wastewater such as sand, coffee grounds, eggshells, gravel, and cinders. The poor safety record of operators in the past may have been caused by which factors? - correct answer Operators not being aware of unsafe conditions. Operators not immediately correcting and safe conditions when they become obvious. Operators not knowing safe procedures. Pieces of metal, rocks, and similar items may cause which problems in wastewater treatment plants? - correct answer Damage or plug pumps. Jams lets collector mechanisms in settling tanks. Plug pipes. Sand, egg shells, and similar materials including grit may cause which problems in wastewater treatment plants? - correct answer Cause excessive wear in pumps. Plug pipes. Use up valuable space and sludge digesters. Which factors may cause the flow diagram or location of processes in your wastewater treatment plant differ from a typical plant? - correct answer characteristics of the wastewater. Construction, operating, and maintenance costs of various processes. Discharge requirements. Quantity of the waste water. Seasonal variations in the quantity and characteristics of the wastewater. Before starting to read material from a manual clean bar screen, the area should be examined for which types of objects or structures that might interfere with the brake handle and knock you off balance? - correct answer Corners of buildings or diversions structures. Electrical wires. Guardrails. Light posts or overhead lights.

Why is the hydrogen sulfide gas produced by septic conditions undesirable? - correct answer Introduce it talks atmosphere. Can produce an explosive atmosphere. Causes corrosion of concrete, metal, and paint. Has a rotten a odor. Which problems could prevent the mechanism from moving in mechanically cleaned screens? - correct answer Equipment broken. Rake mechanism jammed. Sudden high flows or heavy amounts of debris entering a wastewater treatment plant could be caused by which factors? - correct answer Industrial dumps. Sewer line maintenance. Storm flows. How can desired velocities and a grit channels be achieved? - correct answer By adjusting the weirs. by maintaining the proper number of channels in service. Abnormal operating conditions can develop in grit channels under which conditions? - correct answer During peak canning seasons. during pariotic industrial dumps. During periods of heavy snow melt. During rainstorms. Maintenance of grit washing facilities includes which tasks? - correct answer Examining moving parts for wear. Inspection the entire facility for corrosion damage. Oiling and greasing the equipment in accordance with the plant O & M manual and the manufacturer's instructions. Which items should an operator consider when when reviewing the plans and specifications for the racks and screens facilities of a wastewater treatment plant? - correct answer Is there a sufficient number of standby units? Is there room for a rate when when removing screenings? Is there some place to drain and store screenings? Do the plans and specifications adhere to the operation and maintenance O & M requirements of the facilities? Where is the disposal site for screenings? What items should an operator consider when reviewing the plans and specifications for removal facilities of a waste water treatment plant? - correct answer Are there grit dewatering capabilities? Are there a écrit storage facilities and are they adequate? Are there guardrails around the grit chambers or grit channels? Kendrick grit hoppers people easily? How easily can units be clean? Settling tanks increase the waste water velocity far above the velocity in a collection sewer. - correct answer False.

Pumping skimmed solids to a digester is considered good practice. - correct answer False. There is a great deal and operator can do in terms of clarifier operation to improve or maintain clarifier performance under toxic conditions. - correct answer False. The accumulated sludge on the floor of a clarifier should be removed frequently. - correct answer True. As thick as large as possible should be pumped from the clarifier sump with the least amount of water. - correct answer True. As water temperature increases, be settling rate of particles decreases. - correct answer False. As waste water enters a settling tank it should be evenly distribute dispersed across the entire section of the tank and should flow at the same velocity in all areas toward the discharge end. - correct answer True. Actual detention time for a clarifier is often greater than the detention time calculated using the formula. - correct answer False. Trickling filter sloughings are generally quite low in BOD. - correct answer False. Secondary clarifier tanks, which follow the activated sludge process, are designed to handle small volumes of sludge. - correct answer False. Laboratory tests should be conducted to provide a check on accuracy of the monitoring instrumentation.

• correct answer True. Sufficient gas is produced in combined sedimentation digestion units to serve as a reliable source of energy for power or for heating. - correct answer False.

One method of operating septic tank effluent reaching systems is to apply excellent to half of the system while the other half rest to give the system a chance to recover its precolation capacity. - correct answer True. What is the main difference between primary and secondary clarifiers? - correct answer The density of the sludge handled. What is the purpose of a rectangular sedimentation basin effluent trough? - correct answer Collect the settled wastewater flowing over the weirs. What is the purpose of circular clarifier blades and scrapers squeegees? - correct answer Scrape sludge from the bottom of the clarifier to the sump. During normal operations, which daily operation and maintenance tasks should be performed with regard to clarifier flights? - correct answer Examine bolts for looseness, corrosion, and excessive wear on those parts that can be inspected above the waterline. Why should operators perform an annual inspection on each clarifier? - correct answer To help prevent serious problems and failures in the future when harmful consequences can result. In most plants, why do the surface loading and detention time vary widely throughout the day? - correct answer Due to the hourly changes on plant inflow resulting from the activities of the people and industries in the community. What is the only conclusive method of measuring the efficiency of clarifiers? - correct answer By continually observing the quality of the effluent. Why should clarifier weirs be kept level? - correct answer To help prevent short-circuiting, which reduces the efficiency of the clarifier. Why must fats, oils, hair, and other light material be removed by flotation? - correct answer To remove the material as quickly as possible to avoid odor complaints.

If laboratory results indicate a poorly operating clarifier, how can an operator try to identify the problem? - correct answer By training the clarifier and inspecting the interior. During times when the activated sludge process is upset, why must operators be careful that the return sludge rate does not become too high? - correct answer The resulting turbulence in the tank can upset the sludge blanket. What does a combined sedimentation digestion unit consists of? - correct answer A small clarifier constructed over a sludge digester. When should I gestured sledge be withdrawn from the digester of a combined sedimentation digestion unit? - correct answer When solids start appearing in the supernatant. How is the effluent from a septic tank usually disposed of? - correct answer In underground perforated pipes called leach lines. Which types of sludge handling and sludge disposal systems are used at wastewater treatment plants? - correct answer Burial systems. Digestion systems. Land disposal systems. Which items could cause the clarifier squeegee mechanism to jerk or jump? - correct answer An uneven clarifier floor. Problems with the drive unit. Squeeze that have too much drag. Most clarified that do not produce an acceptable effluent usually sell due to which problems? - correct answer Equipment failures. Excessive hydraulic loadings. Operator errors. The installation of which items will help operators maintain clarifier performance under abnormal conditions? - correct answer Chemical feed systems. Control structures. Instrumentation. Monitoring devices. Which items are probable causes of floating sludge and primary clarifiers? - correct answer Insufficient sledge removal. For lunch blanket is too deep. Sludge collection mechanism, or flights are off. Sludge decomposing in the tank is slipping by gasification. Sludge pump runs but discharges are thin or no sludge is pumped.

Which items are possible clarifier problems in operator could encounter? - correct answer Large amounts of floating scum. Loss of solids over the effluent weirs. PH is low and there are odors. Removal efficiencies are low. Sludge blanket is deep but the pump sludge is thin. Which item should an operator check if loading chunks of sludge are observed on the surface of a clarifier? - correct answer Collector mechanism. Pipes and sludge sump. Plant in fluent. Quality of the supernatant return from the digester. Sludge pump. Which items are general maintenance hints will help keep clarifiers operating properly? - correct answer Always lubricate equipment at the intervals recommended by the manufacture. Clean all equipment and structures regularly. Inspect and correct it possible all the killer willy noises, weeks, pressure and vacuum gauge irregular titties, belts, electric systems, and safety devices. Keep the weird level. Maintain a record and file system for future reference. The sedimentation and flotation units commonly used to treat wastewater include which items? - correct answer Combined sedimentation digestion units. Imhoff tanks. Primary clarifiers. Secondary clarifiers. Short-circuiting in clarifiers can be prevented by which means? - correct answer Proper design of inlet channels. Use of battles. Use of port openings. Use of Weir plates. Detention time for a clarifier can be calculated by the use of which known factors? - correct answer Quantity of flow per day. Tank dimensions or volume. Why should operators review the plans and specifications for a wastewater treatment plant. - correct answer To become familiar with a proposed plant. To learn what will be constructed. To look carefully for potential safety hazards. to offer suggestions on how the plant can be designed for easier and more effective operation and maintenance. When reviewing the plans and specifications for a proposed wastewater treatment plant, which safety items should an operator check? - correct answer Adequate guards must be placed over chain drives, belts, and other moving parts. Adequate lighting must be provided on the clarifier. Cat walks and bridges must have floor plates or grapes from a secured and equipped with toe boards and non-skid surfaces. Do not allow any pipe or conduit to cross on top of cat walks or prejudice safety hooks, poles, or should be stationed at strategic locations.

Under normal operating conditions for combined sedimentation digestion units, which test should be performed daily? - correct answer Hose down the baffles, wieners, come trough, and dump it to remove any grease, scum, or other floating debris. Look and listen for anything unusual. Measure the pH in the digester. Observe the flow through the facility and the operation of the equipment. Remove debris and solids from the bar screen and properly dispose of them by burial. Under which circumstances are at normal operating conditions likely to a cure for a combined sedimentation digestion unit? - correct answer Inflows are higher than design closed due to storm water inflow and infiltration. Solids loading are high due to seasonal or industrial discharges. Toxic substances or high or low pH liquids are released into the collection system. Upon which items should the operator focused during an inspection of a combined sedimentation digestion unit? - correct answer Corrosion damage. Cracks and leaks. On painted surfaces. Worn parts. The maintenance of a good growth of organisms on the filter media is crucial to successful trickling filter operation. - correct answer True. True.trickling filters separate the solids from the wastewater by a straining action. - correct answer False. Higher trickling filter loadings and greater efficiency are possible in warmer climates if aerobic conditions can be reasonably maintained in the filter. - correct answer True. The hydraulic loading apply to a trickling filter is the total volume of liquid, including recirculation, expressed as GPD / sq ft. - correct answer True. High rate trickling filter loadings may be lower for synthetic media. - correct answer False. When you have checked out all the equipment mechanically, starting up the trickling filter portion of the plant is very simple. - correct answer True. slime growth on trickling filter media may be accelerated by recirculating wastewater through the trickling filter prior to treating the main waste water flow stream. - correct answer True.

Operation of clarifiers is interconnected with trickling filter operation. - correct answer True. When increasing the recirculation rate on a tripling filter, be sure they hydraulic loading remains within engineering design limits. - correct answer True. For each incoming hundred pounds of BOD entering a trickling filter treatment plant, there should be at least five pounds of ammonia nitrogen and one pound of orthophosphat. - correct answer True. Since operation of trickling filter is an aerobic process, serious odors are likely to exist. - correct answer False. Good grounds maintenance and cleaning up practice will help to minimize fly problems. - correct answer True. Trickling filters respond quickly to operational changes. - correct answer True. Trees should be planted close to open filters to provide shade. - correct answer False. What is the purpose of trickling filter distributor bearings? - correct answer Allow the distributor arms to rotate. What is the purpose of trickling filter media? - correct answer Provide a large surface area on which the biological slime growth develops. Water trickling filters use recirculation, an additional organic (BOD) loading will be placed on the filter. Why is this added loading omitted in most calculations? - correct answer Because it is difficult to measure in recirculated flows. How can some of the unexpected, frustrating problems encounter during the startup of a new plant be avoided? - correct answer By careful inspection ahead of time.

The ability of an operator to correct deficiencies in trickling filter performance will depend on which factors? - correct answer The operator's alertness and ingenuity as well as the design of the collection system and treatment plant. Rapid changes in the influent load to a trickling filter plant can best be estimated by using which test? - correct answer COD. What is the main indicator of how effectively a trickling filter plant is working? - correct answer Plant effluent. In the operation of trickling filters, which item could cause serious odors? - correct answer Excessively high hydraulic loadings. What should be checked when the trickling filter treated effluent quality is poor? - correct answer Organic load on the filter. Why should the turnbuckles be adjusted occasionally on the guy rods of a trickling filter? - correct answer To keep the rotating distributor arms at the proper level. When reviewing plans for a new trickling filter plant with respect to overhead clearance, what should operate check? - correct answer Electrical power and telephone lines will not interfere with any equipment. What is the purpose of secondary treatment? To remove - correct answer Dissolved solids. Very small suspended solids. (colloids) Clogged void spaces and trickling filters can create which operational problems? - correct answer Ponding. Reduction in overall filter efficiency. What are the benefits of recirculation and the resulting sloughing access or aged growths from trickling filter media? - correct answer Improve ventilation through the filter. Prevent ponding.

Which tasks should be performed by operators during the pre-start activities of a new trickling filter plant? - correct answer Be sure the correct oil and a mount of oil are used in oil reservoirs. Check the distributor arms for even adjustments and level. Record the amount and type of oil each reservoir holds. Remove the packing grease from the filter bearings and replace with proper grease. Why should trickling filter recirculation be done during low and slow periods of the day and night? - correct answer To keep the slime growths wet. To minimize filter fly development. To wash off excess of slime gross. What trickling filter problems can result from recirculation rates that are too low? - correct answer Ponding. Reduced BOD removal efficiency. A tripling filter plant effluent that is high in suspended solids could be caused by which factors? - correct answer Gasification (gentrification) caused by septic sludge in the secondary clarifier. heavy sloughing from the filters. High hydraulic loading or short-circuiting through the secondary or final clarifier. Shock loading caused by toxic wastes or hydraulic or organic overloads. An alert operator will note changes in process units by observing which physical factors in a chick clean filter plant? - correct answer Amount of scum on a clarifier. Appearance of the effluent. Flow rate or height over weirs. Launder levels. Spray pattern. Minor ponding in a trickling filter can be eliminated by which methods? - correct answer Dose the filter with chlorine at about 5 mg / L for several hours. Hand turn or stir the filter service with a rake, fork, or bar. Shut off the flow to the filter for several hours. Spray the filter surface with high pressure water stream. Which items are guidelines for maintaining trickling filter is to prevent odor problems? - correct answer Check the ventilation in the trickling filter. Do everything possible to maintain aerobic conditions in the sewer collection system and in the primary treatment units. Increase the recirculation rate to provide more oxygen to the filter bed and increase sloughing. Keep the waste water splash from the distributor away from exposed structures, grass, and other surfaces. Provide a forced air ventilation system and odor control of the exhaust air stream for covered filters. When are plant in clothes considered abnormal? When there are - correct answer Extreme levels of biochemical oxygen demand (BOD). Extreme levels of suspended solids. High flow rates. Inflow of a septic influent.

Which items are typical influent toxic conditions? - correct answer Excess mount of ammonia. Excessive amounts of heavy metals. Excessive amounts of hydrocarbons. Excessively high or low PH. Which items are probable causes of trickling filter odors? - correct answer Anaerobic waste being applied to the filters. Excessive biological growth. poor housekeeping. Poor ventilation of the filter. Why should operators review plans and specifications for a new plant? - correct answer To become familiar with the proposed plant. To learn what will be constructed. To offer suggestions on how the plant can be designed for easier and more effective operation and maintenance. When reviewing plans for a new plant, operators should carefully study which areas? - correct answer Equipment. Safety aspects. Site. Trickling filter structure. Rotating biological contactors (RBCs) alright primary biological treatment process for domestic and biodegradable industrial waste. - correct answer False. Organisms on the first-stage media of a rotating biological contactor (RBC) are exposed to high levels of BOD and reduce the BOD at a high rate. - correct answer True. Rotating biological contactors are less sensitive to industrial wastes than trickling filters. - correct answer False. If you waste water flow is perpendicular to the rotating media shaft of a rotating biological contactor, the media should be moving to the waste water in the direction of flow. - correct answer False. If the optimum range of influent pH to a rotating biological contactor RBC plant is exceeded at any time due to the industrial waste discharges, for example an increase in treatment efficiency is likely. - correct answer False. One advantange of rotating biological contactor RBC units is the fact that high flows usually wash the slime growths off the media. - correct answer False.

A loss in rotating biological contactor process efficiency can result at the slimes are washed off the media. - correct answer True. Always shut off the power to a rotating biological contactor unit, tag the switch, and lost the main breaker in the off position before working on the unit. - correct answer True. Good personal hygiene must be practiced by operators at all times. - correct answer True. What is a biodegradable waste? - correct answer Organic matter that can be broken down by bacteria to more stable forms that will not create a nuisance or give off foul odors. How is oxygen provided for the organisms in the rotating biological contactor treatment process? - correct answer By rotating disk climb into the settled waste water and then into the atmosphere. How are sloughed slimes in the effluent from rotating biological contactor is removed from the effluent?

• correct answer By settling in the secondary clarifier. What is the purpose of the rotating media of a rotating biological contactor RBC? - correct answer To provide support for organisms. What is soluble BOD? - correct answer A measure of food for microorganisms that is dissolved in the water being treated. As close to a rotating biological contactor unit increase, why will a fluent values of the various water quality indicators increase? - correct answer Because there will be more slimes on the media. Why are rotating biological contactor influent and effluent data often plotted at 7 day moving averages? - correct answer To smooth out daily fluctuations and reveal trends. When doing with nitrification in the rotating biological contactor process, which items are very critical? - correct answer PH and alkalinity.

What are inhibitory substances? - correct answer Materials that kill or restrict the ability of organisms to treat waste. What could be the cause of rotating biological contactor sloughing or loss of biomass? - correct answer Influent wastewater containing toxic or inhibitory substances. Why should slime growth not be washed off the media of a rotating biological contactor? - correct answer Because you will be washing away the organisms that treat the wastewater. What should be done if Greaseballs appear on the water surface in the rotating biological contactor bays? - correct answer Remove them with a dip net or screen device. Why are rotating biological contactors covered? - correct answer To avoid exposure of the media to sunlight, which may cause the media to become brittle. To prevent intense rains from washing off some of the slime process. To protect biological slime grows from freezing. To provide protection for operators from Sun, rain, snow or when while maintaining the equipment. To stop exposure of the media to direct sunlight to prevent the growth of algae. It grit and large organic matter are not removed by pre treatment before the wastewater being treated reaches the rotating biological contactor unit, the material can settle beneath the drums and forms large deposit that can cause which problems? - correct answer Produced septic conditions. Reduce the effect of Tape Vol. Scrape the slimes from the media. Stall the unit. who should instruct the operator on the proper operation of a rotating biological contactor plant and the maintenance of the equipment? - correct answer Design engineer. Manufacturer's representative. Before starting any equipment or allowing any wastewater to enter the rotating biological contactor treatment process, which area should be inspected for clearances? - correct answer Between the chain casing and the media. Between the media and the baffles or the cover support beams. Between the media and the tank wall. Between the roller chain, the sprockets, and the chain casing. Rotating biological contactor treatment plants are not difficult to operate and produces a good excellent provided the operator properly regularly performs which basic duties? - correct answer Inspecting the equipment. Maintaining the equipment. Observing and media. Taking corrective action when necessary. Testing the influent and effluent.

Which items should be checked when inspecting rotating biological contactor equipped? - correct answer Till the motors to determine if they are running hot. Fill the outer housing of the shaft bearing to see if it is running hot. Inspect the belts for proper tension. Inspect the chain drive for alignment and tightness. Listen for unusual noises in the motor bearings. Which items are appropriate safety gear when handling chemicals? - correct answer Goggles or face shield. Impervious gloves. Protective clothing. What are the probable cause of decreased rotating biological contactor treatment efficiency? - correct answer Hydraulic overload. Low waste water temperatures. Organic overload. PH being too high or too low. Which items are probable causes of a noisy chain drive on a rotating biological contactor? - correct answer Chain not fitting the sprockets. Faulty lubrication. This chain. Misalignment an improper assembly. Moving parts rubbing stationary parts. Which items are potential safety hazards when operating a rotating biological contactor unit? - correct answer Infections and diseases. Slippery surfaces. Slow moving equipment. wiring and connections. Hydraulic and organic loadings on rotating biological contactor depends on which factors? - correct answer Absolute total and soluble BOD requirements. Influent soluble BOD. Waste water temperature.