WATER TREATMENT GRADE 2 NEWEST 2025 EXAM COMPLETE 230 QUESTIONS AND CORRECT
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+||BRAND NEW!!
In lime softening facilities, it is normally good practice store a minimum of _____ supply of each
chemical. - answer-1 months
What is the term for a conical tank in which the softening reactions take place quite rapidly as the water
swirls upward trough the unit? - answer-pellet reactor
When magnesium hardness is treated with lime, what is precipitated? - answer-magnesium hydroxide
Why is soda ash needed to remove noncarbonate hardness? - answer-to serve as an additional
carbonate to form calcium carbonate
What happens when quicklime is added to water? - answer-it gets hot and forms hydrated lime in a
slurry
What is carbon dioxide used for in lime softening? - answer-to correct the ph and stabilize the water
prior to filtration
What federal regulation requires tat samples from customers' taps be analyzed for the presence of lead
and copper? - answer-lead and copper rule
Which of the following is the best type of salt to use in the regeneration of ion exchange softener resin?
- answer-rock salt or pellet-type salt
Once the ion exchange resin can no longer remove hardness, it is said to be - answer-exhausted
When backwashing a ion exchange unit, how much should the bed expand from water introduced from
the bottom of the ion exchange column? - answer-50-75%
,Ion exchange processes can typically be used for direct groundwater treatment as long as turbidity and
_________ levels are not excessive. - answer-iron
Weak-base anion exchange resins behave much like their weak-acid counterparts; they do not remove
anions above a ph of - answer-6
Block salt is sometimes used for home softeners, but it is not suitable for larger installations because -
answer-its small surface area does not allow it to dissolve fast enough
What are cations? - answer-positively charged ions, such as calcium and magnesium, that migrate
toward the cathode
What is another term for the service cycle? - answer-operational cycle
What element in source water acts as the precursor to disinfection by-product production? - answer-
total organic carbon
Powdered activated carbon is primarily used to control - answer-organic compounds responsible for
tastes and odors
Gac contractors can be used when formation of trihalomethanes or other disinfection by-products
_______ an adjustment of the disinfectants or other treatment processes. - answer-cannot be
prevented by
Which f the following happens at the surfaces of the pac particles if they are coated with coagulants or
other water treatment chemicals? - answer-they lose their capacity to absorb
How should burning carbon be handled? - answer-it should be covered with a fine mist of spray from a
hose or chemical foam extinguisher
In a slurry feed system, where should the feeder be located to ensure there is no danger that the carbon
will settle out in the feed line because of the low flow velocity? - answer-at exactly the feed point
, In a slurry feed system, day tanks are typically made of what material? - answer-fiberglass
Which type of aerator causes aeration to occur in splash areas and can be used to oxidize iron and to
partially reduce dissolved gasses? - answer-cascade aerator
Which type of aerator is much more efficient in removing dissolved gasses and for oxidizing iron and
manganese? - answer-draft aerato
Which of the following is the normal air-to-water ratio at peak low in a packed tower aerator? - answer-
25:1
____________ aerators draw water into the blade of the aerator and throw the water into the air in tiny
droplets, so that water can pick up oxygen. - answer-surface
Which type of aerator consists of a propeller-like mixing blade mounted on the end of a vertical shaft
driven by a motor? - answer-mechanical aerator
In a slate-and-coke-tray aerator, the aerator is usually constructed to have sloping sides, called
__________, which are used to protect the splash from wind loss and freezing. - answer-splash aprons
List five components of a ring-type cascade aerator. - answer-any five of the following: central feed pipe,
splash guard, catch bowl, deflector plate, collector pan, overflow baffle, spray bottle, outlet, inlet,
aluminum flange
In general, spray aeration i successful in oxidizing iron or manganese and is very successful in increasing
what characteristics of water? - answer-diffused oxygen level
Which of the following is not a component of a typical hollow-fiber module? - answer-reverse osmosis
membrane
Process recovery is typically ________ percent fr surface and can be as high as _________ percent. -
answer-95;97
DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+||BRAND NEW!!
In lime softening facilities, it is normally good practice store a minimum of _____ supply of each
chemical. - answer-1 months
What is the term for a conical tank in which the softening reactions take place quite rapidly as the water
swirls upward trough the unit? - answer-pellet reactor
When magnesium hardness is treated with lime, what is precipitated? - answer-magnesium hydroxide
Why is soda ash needed to remove noncarbonate hardness? - answer-to serve as an additional
carbonate to form calcium carbonate
What happens when quicklime is added to water? - answer-it gets hot and forms hydrated lime in a
slurry
What is carbon dioxide used for in lime softening? - answer-to correct the ph and stabilize the water
prior to filtration
What federal regulation requires tat samples from customers' taps be analyzed for the presence of lead
and copper? - answer-lead and copper rule
Which of the following is the best type of salt to use in the regeneration of ion exchange softener resin?
- answer-rock salt or pellet-type salt
Once the ion exchange resin can no longer remove hardness, it is said to be - answer-exhausted
When backwashing a ion exchange unit, how much should the bed expand from water introduced from
the bottom of the ion exchange column? - answer-50-75%
,Ion exchange processes can typically be used for direct groundwater treatment as long as turbidity and
_________ levels are not excessive. - answer-iron
Weak-base anion exchange resins behave much like their weak-acid counterparts; they do not remove
anions above a ph of - answer-6
Block salt is sometimes used for home softeners, but it is not suitable for larger installations because -
answer-its small surface area does not allow it to dissolve fast enough
What are cations? - answer-positively charged ions, such as calcium and magnesium, that migrate
toward the cathode
What is another term for the service cycle? - answer-operational cycle
What element in source water acts as the precursor to disinfection by-product production? - answer-
total organic carbon
Powdered activated carbon is primarily used to control - answer-organic compounds responsible for
tastes and odors
Gac contractors can be used when formation of trihalomethanes or other disinfection by-products
_______ an adjustment of the disinfectants or other treatment processes. - answer-cannot be
prevented by
Which f the following happens at the surfaces of the pac particles if they are coated with coagulants or
other water treatment chemicals? - answer-they lose their capacity to absorb
How should burning carbon be handled? - answer-it should be covered with a fine mist of spray from a
hose or chemical foam extinguisher
In a slurry feed system, where should the feeder be located to ensure there is no danger that the carbon
will settle out in the feed line because of the low flow velocity? - answer-at exactly the feed point
, In a slurry feed system, day tanks are typically made of what material? - answer-fiberglass
Which type of aerator causes aeration to occur in splash areas and can be used to oxidize iron and to
partially reduce dissolved gasses? - answer-cascade aerator
Which type of aerator is much more efficient in removing dissolved gasses and for oxidizing iron and
manganese? - answer-draft aerato
Which of the following is the normal air-to-water ratio at peak low in a packed tower aerator? - answer-
25:1
____________ aerators draw water into the blade of the aerator and throw the water into the air in tiny
droplets, so that water can pick up oxygen. - answer-surface
Which type of aerator consists of a propeller-like mixing blade mounted on the end of a vertical shaft
driven by a motor? - answer-mechanical aerator
In a slate-and-coke-tray aerator, the aerator is usually constructed to have sloping sides, called
__________, which are used to protect the splash from wind loss and freezing. - answer-splash aprons
List five components of a ring-type cascade aerator. - answer-any five of the following: central feed pipe,
splash guard, catch bowl, deflector plate, collector pan, overflow baffle, spray bottle, outlet, inlet,
aluminum flange
In general, spray aeration i successful in oxidizing iron or manganese and is very successful in increasing
what characteristics of water? - answer-diffused oxygen level
Which of the following is not a component of a typical hollow-fiber module? - answer-reverse osmosis
membrane
Process recovery is typically ________ percent fr surface and can be as high as _________ percent. -
answer-95;97
