Water Treatment Plant Operation Volume 2 Chapter 17
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Questions and Answers
- 1.
Under the national pollutants discharge lamination system(NPDES) provisions, permits are not required to discharge wastes from a water treatment plant
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Under the national pollutants discharge elimination system (NPDES) provisions, permits are required to discharge wastes from a water treatment plant. The NPDES is a regulatory program that controls water pollution by regulating point sources that discharge pollutants into waters of the United States. A water treatment plant is considered a point source, and therefore, it is subject to the requirements of the NPDES program. This means that a permit is necessary in order to legally discharge wastes from a water treatment plant. Therefore, the statement that permits are not required to discharge wastes from a water treatment plant is false.Rate this question:
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- 2.
The most important part of an operator job is the end product: good portable water
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because the end product of an operator's job is indeed good portable water. This implies that the main objective of an operator is to ensure that the water being produced meets the necessary standards for portability. This could involve tasks such as monitoring water quality, maintaining equipment, and implementing treatment processes to remove impurities. Ultimately, the goal is to provide safe and clean water for consumption by the public.Rate this question:
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- 3.
Not all waters can be treated by using polymers instead of alum
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Polymers are often used as an alternative to alum for water treatment. However, not all types of water can be effectively treated using polymers. Certain water sources may contain specific contaminants or have unique characteristics that require the use of alum or other treatment methods. Therefore, it is true that not all waters can be treated using polymers instead of alum.Rate this question:
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- 4.
During the draining stages of a sedimentation tank, the walls and all the equipment should be completely hose down and inspected for damage
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
During the draining stages of a sedimentation tank, it is important to hose down and inspect the walls and equipment for damage. This is because sedimentation tanks can accumulate sediment and debris over time, which can cause damage to the walls and equipment. By hosing down the tank and inspecting for damage, any potential issues can be identified and addressed before they become more serious. Therefore, the statement "True" is correct.Rate this question:
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- 5.
All gears, sprockets, and moving parts in the sedimentation basin should be lubricated immediately after hosing down to prevent freeze up resulting from exposure to air and and during inspection and repair
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because lubricating the gears, sprockets, and moving parts in the sedimentation basin immediately after hosing down helps to prevent freeze up. Exposure to air can cause these parts to freeze, especially during inspection and repair. By lubricating them, the risk of freeze up is reduced, ensuring that the sedimentation basin operates smoothly and efficiently.Rate this question:
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- 6.
Polymer sludges are not suitable as a soil conditioner
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Polymer sludges are suitable as a soil conditioner. Soil conditioners are substances that improve the physical properties of soil, such as its structure, water retention, and nutrient-holding capacity. Polymer sludges, which are derived from polymers, can be used as soil conditioners to enhance soil quality. They help improve soil structure, increase water infiltration and retention, and promote nutrient availability for plants. Therefore, the statement that polymer sludges are not suitable as a soil conditioner is false.Rate this question:
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- 7.
When removing dried sludge from sand drying beds, the operator must exercise extreme caution so that only the drive sludges picked up with the minimum possible disturbance to the sand and aggregate
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because when removing dried sludge from sand drying beds, it is important to exercise extreme caution to minimize disturbance to the sand and aggregate. This is because any disturbance to the sand and aggregate can lead to contamination and affect the overall quality of the sand. Therefore, the operator must be careful and ensure that only the dried sludge is picked up without causing any unnecessary disturbance to the sand and aggregate.Rate this question:
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- 8.
Brine from an ion exchange unit maybe discharged into wastewater collection
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Brine from an ion exchange unit may be discharged into wastewater collection because ion exchange units are commonly used to remove contaminants from water by exchanging ions. The brine, which contains the removed contaminants, can be discharged into the wastewater collection system for further treatment or disposal. This is a common practice in many industries and municipal water treatment facilities.Rate this question:
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- 9.
Alum sludge has a tendency to call soils to harden; thus, it provides a beneficial
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Alum sludge does not have a tendency to cause soils to harden; therefore, it does not provide a beneficial effect.Rate this question:
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- 10.
Septic tank pumps used to pump sludge, especially the suction hose, must be thoroughly rinsed and disinfected before using any water treatment plant
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Septic tank pumps are used to pump sludge, which contains waste and potentially harmful bacteria. If the suction hose of the pump is not properly rinsed and disinfected before using it in a water treatment plant, it can contaminate the water with harmful bacteria and other contaminants. Therefore, it is important to thoroughly clean and disinfect the pump and its components before using them in a water treatment plant to ensure the safety and quality of the treated water.Rate this question:
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- 11.
What is an operators wants ability with regard to all byproduct and waste from a water treatment plant
- A.
Discharge dirty backwash watering to lakes and rivers
- B.
Disposal into the nearest receiving waters
- C.
Proper disposal and an acceptable and document the matter
- D.
Transport byproduct and waste to storm drains
Correct Answer
C. Proper disposal and an acceptable and document the matterExplanation
The correct answer is "Proper disposal and an acceptable and document the matter." This answer suggests that operators should dispose of the byproduct and waste from a water treatment plant in a proper and acceptable manner, and also document the disposal process. This ensures that the waste is handled in a responsible and environmentally friendly way, and that there is a record of the disposal for regulatory and accountability purposes.Rate this question:
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- 12.
How does water temperature influence the volume of sludge produced
- A.
As temperature increases, the biological activity of the bacteria will increase
- B.
As temperature increases, the flocculation factor of the solids will increase
- C.
As temperature increases, the sedimentation tank bottom attract the solids
- D.
As temperature increases the settling rate of the solids will increase
Correct Answer
D. As temperature increases the settling rate of the solids will increaseExplanation
As the temperature increases, the settling rate of the solids will increase. This is because higher temperatures increase the kinetic energy of particles, causing them to move more quickly and settle at a faster rate. This can be beneficial in wastewater treatment processes, as it allows for more efficient separation of solids from the water.Rate this question:
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- 13.
How does increasing the detention time influence the volume of sludge produced
- A.
The amount of solids that settled out will increase
- B.
The biological activity of the bacteria will increase
- C.
The flocculation factor of the solids will increase
- D.
The sedimentation tank bottom attracts the solids
Correct Answer
A. The amount of solids that settled out will increaseExplanation
Increasing the detention time refers to increasing the amount of time wastewater remains in a sedimentation tank. This allows more time for solids to settle out from the water. As a result, the amount of solids that settle out will increase, leading to an increase in the volume of sludge produced.Rate this question:
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- 14.
The sludge build up any sedimentation tank can interfere with which treatment process
- A.
Coagulation flocculation
- B.
Filtration in disinfection
- C.
Ion exchange and softening
- D.
Screening and sedimentation
Correct Answer
B. Filtration in disinfectionExplanation
The correct answer is Filtration in disinfection. Sludge build-up in a sedimentation tank can interfere with the filtration process during disinfection. Filtration is an important step in the disinfection process as it helps remove any remaining impurities and pathogens from the water. However, if there is sludge build-up in the sedimentation tank, it can clog the filters and reduce their effectiveness, leading to inadequate disinfection of the water. Therefore, it is crucial to prevent sludge build-up and ensure proper maintenance of the sedimentation tank to ensure efficient filtration in disinfection.Rate this question:
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- 15.
What is the purpose of backwash recovery ponds or lagoons after the filters have been back washed
- A.
To protect the local groundwater
- B.
To recycle the water through the treatment plant
- C.
To reuse the solids for enhanced coagulation
- D.
To separate the water from the solids
Correct Answer
D. To separate the water from the solidsExplanation
Backwash recovery ponds or lagoons are used to separate the water from the solids after the filters have been backwashed. This is done to ensure that the solids are properly collected and can be disposed of or reused appropriately. By separating the water from the solids, the water can be further treated or recycled, while the solids can be either reused for enhanced coagulation or disposed of in a proper manner. This helps to maintain the efficiency and effectiveness of the water treatment process and protects the local groundwater from contamination.Rate this question:
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- 16.
What is sludge thickening
- A.
Pretreatment of sludge to facilitate removal of water and subsequent treatment processes
- B.
Treatment by centrifugal or rotational forces to separate solids from liquids
- C.
Treatment that removes or separates a portion of the water present in a sludge or slurry
- D.
Treatment to remove water from the sludge mass to reduce the volume that must be handled
Correct Answer
D. Treatment to remove water from the sludge mass to reduce the volume that must be handledExplanation
Sludge thickening refers to the treatment process of removing water from the sludge mass in order to reduce the volume that needs to be handled. This is done to make the sludge easier to manage and to minimize the costs associated with its transportation and disposal. By removing water, the sludge becomes thicker and more concentrated, allowing for more efficient subsequent treatment processes.Rate this question:
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- 17.
What is sludge conditioning
- A.
Pretreatment of sludge to facilitate removal of water and subsequent treatment processes
- B.
Treatment by centrifugal or rotational forces to separate solids from liquids
- C.
Treatment that removes or separates a portion of the water present in a sludge or slurry
- D.
Treatment to remove water from the sludge mass to reduce the volume that must be handled
Correct Answer
A. Pretreatment of sludge to facilitate removal of water and subsequent treatment processesExplanation
Sludge conditioning refers to the pretreatment of sludge in order to make it easier to remove water and to prepare it for subsequent treatment processes. This process involves various techniques and chemicals that help in breaking down the sludge, improving its dewatering properties, and enhancing the efficiency of the treatment processes that follow. It helps in reducing the volume of sludge that needs to be handled and improves the overall effectiveness of sludge treatment.Rate this question:
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- 18.
When should the cleaning of sedimentation tanks be done
- A.
Before or after peak demand months
- B.
Before schedule visits by regulatory agencies
- C.
When all of the operators are available to help perform this task
- D.
When receiving waters can’t assimilate the water discharges
Correct Answer
A. Before or after peak demand monthsExplanation
The cleaning of sedimentation tanks should be done before or after peak demand months because during peak demand months, the tanks are likely to be filled with a higher volume of sediment and debris. Cleaning the tanks before or after peak demand months ensures that they are operating at optimal efficiency and can handle the increased demand without any issues.Rate this question:
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- 19.
What should happen of the water table is high when draining an in ground tank
- A.
An empty tank could float like a cork in the water surface and caused considerable damage to the tank and piping
- B.
Extra pumps maybe needed to drain the hole
- C.
Nearby Wells maybe adversely affected by draining the groundwater
- D.
The water could drain into a sewer and overload the wastewater treatment plant
Correct Answer
A. An empty tank could float like a cork in the water surface and caused considerable damage to the tank and pipingExplanation
If the water table is high when draining an in-ground tank, an empty tank could float like a cork on the water surface. This can lead to significant damage to the tank and piping.Rate this question:
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- 20.
How can the efficiency of the Sand drying bed dewatering process be greatly improved
- A.
By enhancing the intensity of solar radiation
- B.
By exposing the process to environmental precipitation
- C.
By preconditioning the process sludge with chemical coagulants
- D.
By protecting the drying bed from windy conditions
Correct Answer
C. By preconditioning the process sludge with chemical coagulantsExplanation
Preconditioning the process sludge with chemical coagulants can greatly improve the efficiency of the Sand drying bed dewatering process. Chemical coagulants help in the formation of larger and denser flocs, which settle faster and improve the dewatering process. This reduces the amount of time required for the sludge to dry, resulting in a more efficient process. Additionally, chemical coagulants can also help in reducing the moisture content in the sludge, further improving the dewatering efficiency.Rate this question:
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- 21.
Regulatory agencies have established programs to enforce rules to prevent any waste discharges that could cause what kind of problems
- A.
Harm to aquatic life
- B.
Harm to plant life
- C.
Harm to the environment
- D.
Receiving water discoloration
- E.
Receiving water pollution
Correct Answer(s)
A. Harm to aquatic life
B. Harm to plant life
C. Harm to the environment
D. Receiving water discoloration
E. Receiving water pollutionExplanation
Regulatory agencies have established programs to enforce rules in order to prevent waste discharges that could cause harm to aquatic life, harm to plant life, harm to the environment, receiving water discoloration, and receiving water pollution. These programs aim to protect the ecosystem and maintain the balance of the environment by ensuring that waste discharges do not negatively impact the water bodies and the organisms that depend on them. By enforcing these rules, regulatory agencies work towards maintaining the health and sustainability of aquatic ecosystems and preventing any potential damage caused by waste discharges.Rate this question:
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- 22.
Which water quality indicators are subject to waste discharge limitation
- A.
PH
- B.
Total iron and manganese
- C.
Total residual chlorine
- D.
Turbidity
- E.
Visible forms of waste
Correct Answer(s)
A. PH
B. Total iron and manganese
C. Total residual chlorine
D. Turbidity
E. Visible forms of wasteExplanation
Water quality indicators that are subject to waste discharge limitation include pH, total iron and manganese, total residual chlorine, turbidity, and visible forms of waste. These indicators are monitored and regulated to ensure that waste discharge does not exceed acceptable levels and cause harm to the environment and human health.Rate this question:
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- 23.
How are sludges the watered at water treatment plants
- A.
Belt presses
- B.
Centrifuges
- C.
Filter presses
- D.
Sand drying beds
- E.
Vacuum filters
Correct Answer(s)
A. Belt presses
B. Centrifuges
C. Filter presses
D. Sand drying beds
E. Vacuum filtersExplanation
Sludges at water treatment plants are typically dewatered using various methods such as belt presses, centrifuges, filter presses, sand drying beds, and vacuum filters. These techniques help separate the water from the solid sludge, allowing for easier disposal or further treatment of the sludge.Rate this question:
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- 24.
The amount of sludge accumulated at a water treatment plan depends on which factor
- A.
amount of suspended matter in sourced water
- B.
level of coagulant dosage
- C.
type of coagulant used
- D.
type of consumer served
- E.
type of suspended matter in the source water
Correct Answer(s)
A. amount of suspended matter in sourced water
B. level of coagulant dosage
C. type of coagulant used
E. type of suspended matter in the source waterExplanation
The amount of sludge accumulated at a water treatment plant depends on multiple factors. These factors include the amount of suspended matter in the sourced water, the level of coagulant dosage, the type of coagulant used, and the type of suspended matter in the source water. The presence of suspended matter in the water can lead to the formation of sludge during the treatment process. The level of coagulant dosage and the type of coagulant used can affect the efficiency of the treatment process and the amount of sludge generated. Additionally, different types of suspended matter in the source water may have varying characteristics that influence sludge formation.Rate this question:
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- 25.
What are the advantages of using organic polymers instead of alum to reduced ability at a water treatment plant
- A.
Easier to Dewater sludge
- B.
Eliminates sludge hoppers
- C.
Eliminate sludge scrapers
- D.
Reduces the quantity of sludge produced
- E.
Relatively denser sludge
Correct Answer(s)
A. Easier to Dewater sludge
D. Reduces the quantity of sludge produced
E. Relatively denser sludgeExplanation
Using organic polymers instead of alum in a water treatment plant offers several advantages. Firstly, it makes it easier to dewater sludge, meaning that the process of removing water from the sludge becomes more efficient. Secondly, it reduces the quantity of sludge produced, which is beneficial as it decreases the amount of waste that needs to be managed. Lastly, organic polymers result in relatively denser sludge, which can make handling and disposal of the sludge easier.Rate this question:
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- 26.
Which processes are used by larger plants that produce large volumes of sludge to reduce the volume of sludge that must be handled and ultimately disposed of
- A.
Conditioning
- B.
Dewatering
- C.
Incinerating
- D.
Thawing
- E.
Thickening
Correct Answer(s)
A. Conditioning
B. Dewatering
E. ThickeningExplanation
Larger plants that produce large volumes of sludge need processes to reduce the volume of sludge that must be handled and disposed of. Conditioning is a process that involves adding chemicals or heat to the sludge to break down organic matter and make it easier to handle. Dewatering is the process of removing water from the sludge, further reducing its volume. Thickening is the process of increasing the solids content of the sludge, also reducing its volume. These processes are used in combination to effectively reduce the volume of sludge and make it more manageable for disposal. Incinerating and thawing are not mentioned as processes used for reducing sludge volume.Rate this question:
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- 27.
Which processes are used to dewater sludges
- A.
belt filter presses
- B.
centrifuges
- C.
polymers
- D.
sand drying beds
- E.
Solar lagoons
Correct Answer(s)
A. belt filter presses
B. centrifuges
D. sand drying beds
E. Solar lagoonsExplanation
The processes used to dewater sludges include belt filter presses, centrifuges, sand drying beds, and solar lagoons. Belt filter presses are mechanical devices that apply pressure to remove water from sludge. Centrifuges use centrifugal force to separate water from sludge. Sand drying beds involve spreading sludge on a bed of sand, allowing water to drain out through the sand. Solar lagoons use solar energy to evaporate water from sludge. These processes are commonly used in wastewater treatment plants to reduce the volume and moisture content of sludge.Rate this question:
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- 28.
Which safety precautions must be exercised by operators when working in any closed tank(Confined space)
- A.
Do not operate gasoline engines in the tank
- B.
Provide adequate ventilation of clean air at all times
- C.
Provide a source of water to clean off boots and tools when the operator comes out of the tank
- D.
Testy atmosphere in the tank for flammable, explosive gases, toxic gases, and oxygen deficiencies
- E.
Use the buddy system
Correct Answer(s)
A. Do not operate gasoline engines in the tank
B. Provide adequate ventilation of clean air at all times
C. Provide a source of water to clean off boots and tools when the operator comes out of the tank
D. Testy atmosphere in the tank for flammable, explosive gases, toxic gases, and oxygen deficiencies
E. Use the buddy systemExplanation
When working in a closed tank or confined space, operators must follow several safety precautions. Firstly, they should not operate gasoline engines in the tank to prevent the risk of fire or explosion. Secondly, it is essential to provide adequate ventilation of clean air at all times to ensure a safe working environment and prevent the buildup of harmful gases. Additionally, operators should have access to a source of water to clean off their boots and tools when they come out of the tank, reducing the risk of contamination. Furthermore, it is crucial to test the atmosphere in the tank for flammable, explosive gases, toxic gases, and oxygen deficiencies to identify potential hazards. Lastly, using the buddy system ensures that there is always someone present to provide assistance or raise an alarm in case of an emergency.Rate this question:
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- 29.
Which factors influence the frequency of removal of dried sludge from sand drying beds
- A.
Drying conditions(weather)
- B.
Permeability of sludge
- C.
Porosity of sludge
- D.
Size of drying buds
- E.
Volume of sludge produced
Correct Answer(s)
A. Drying conditions(weather)
D. Size of drying buds
E. Volume of sludge producedExplanation
The frequency of removal of dried sludge from sand drying beds is influenced by drying conditions (weather) because different weather conditions can affect the rate at which the sludge dries. The size of drying beds also plays a role as larger beds can hold more sludge and may require less frequent removal. Additionally, the volume of sludge produced is a factor as larger volumes will require more frequent removal. The permeability and porosity of the sludge may also have an impact on the drying process, but they are not mentioned in the given factors.Rate this question:
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- 30.
why are continues belt filter presses popular for sludge dewatering
- A.
ability to produce relatively dry filter cake
- B.
containment of orders
- C.
ease of operation
- D.
low energy consumption
- E.
small land requirements
Correct Answer(s)
A. ability to produce relatively dry filter cake
C. ease of operation
D. low energy consumption
E. small land requirementsExplanation
Continuous belt filter presses are popular for sludge dewatering due to several reasons. Firstly, they have the ability to produce a relatively dry filter cake, which is desirable for efficient dewatering. Secondly, they are easy to operate, making them user-friendly and convenient for operators. Additionally, continuous belt filter presses have low energy consumption, making them cost-effective and environmentally friendly. Lastly, they have small land requirements, making them suitable for installations with limited space.Rate this question:
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