WATER TREATMENT GRADE 2 EXAM 2025
WITH ACTUAL CORRECT QUESTIONS AND
VERIFIED DETAILED ANSWERS |FREQUENTLY
TESTED QUESTIONS AND SOLUTIONS
|ALREADY GRADED A+|BRAND
NEW!!|GUARANTEED PASS|LATEST UPDATE
once the ion exchange resin can no longer remove hardness, it is said to be
exhausted
when backwashing a ion exchange unit, how much should the bed expand from water introduced from
the bottom of the ion exchange column?
50-75%
ion exchange processes can typically be used for direct groundwater treatment as long as turbidity and
_________ levels are not excessive.
iron
weak-base anion exchange resins behave much like their weak-acid counterparts; they do not remove
anions above a pH of
6
block salt is sometimes used for home softeners, but it is not suitable for larger installations because
its small surface area does not allow it to dissolve fast enough
what are cations?
positively charged ions, such as calcium and magnesium, that migrate toward the cathode
what is another term for the service cycle?
operational cycle
what element in source water acts as the precursor to disinfection by-product production?
total organic carbon
1|Page
,powdered activated carbon is primarily used to control
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.
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?
they lose their capacity to absorb
how should burning carbon be handled?
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?
at exactly the feed point
in a slurry feed system, day tanks are typically made of what material?
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?
cascade aerator
which type of aerator is much more efficient in removing dissolved gasses and for oxidizing iron and
manganese?
draft aerato
which of the following is the normal air-to-water ratio at peak low in a packed tower aerator?
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.
surface
which type of aerator consists of a propeller-like mixing blade mounted on the end of a vertical shaft
driven by a motor?
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.
splash aprons
2|Page
, list five components of a ring-type cascade aerator.
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?
diffused oxygen level
which of the following is NOT a component of a typical hollow-fiber module?
reverse osmosis membrane
process recovery is typically ________ percent fr surface and can be as high as _________ percent.
95;97
in a typical reverse osmosis flow schematic, which of the following components most closely follows the
cartridge filter?
high-pressure pump
what process is defined as the ratio of the volume of product water, or permeate produced, to raw
water treated?
recovery
what term describes the raw water that has undergone pretreatment (acidification or scale inhibitor
addition) prior to entering the membrane arrays?
feedwater
in the precipitative softening plant, what percentage of solids sludge is produced?
5%
which sludge disposal method is most economical for lime-soda ash softening plants?
lagoons
what process is used to concentrate sludge?
thickener
what process is used to dewater sludge?
sand bed
in a rectangular basin, which type of collector uses suction pipes or a submersible pump to withdraw the
sludge from the basin?
floating-bridge siphon collector
in a drying bed, t sand I usually how deep?
3|Page
WITH ACTUAL CORRECT QUESTIONS AND
VERIFIED DETAILED ANSWERS |FREQUENTLY
TESTED QUESTIONS AND SOLUTIONS
|ALREADY GRADED A+|BRAND
NEW!!|GUARANTEED PASS|LATEST UPDATE
once the ion exchange resin can no longer remove hardness, it is said to be
exhausted
when backwashing a ion exchange unit, how much should the bed expand from water introduced from
the bottom of the ion exchange column?
50-75%
ion exchange processes can typically be used for direct groundwater treatment as long as turbidity and
_________ levels are not excessive.
iron
weak-base anion exchange resins behave much like their weak-acid counterparts; they do not remove
anions above a pH of
6
block salt is sometimes used for home softeners, but it is not suitable for larger installations because
its small surface area does not allow it to dissolve fast enough
what are cations?
positively charged ions, such as calcium and magnesium, that migrate toward the cathode
what is another term for the service cycle?
operational cycle
what element in source water acts as the precursor to disinfection by-product production?
total organic carbon
1|Page
,powdered activated carbon is primarily used to control
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.
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?
they lose their capacity to absorb
how should burning carbon be handled?
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?
at exactly the feed point
in a slurry feed system, day tanks are typically made of what material?
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?
cascade aerator
which type of aerator is much more efficient in removing dissolved gasses and for oxidizing iron and
manganese?
draft aerato
which of the following is the normal air-to-water ratio at peak low in a packed tower aerator?
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.
surface
which type of aerator consists of a propeller-like mixing blade mounted on the end of a vertical shaft
driven by a motor?
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.
splash aprons
2|Page
, list five components of a ring-type cascade aerator.
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?
diffused oxygen level
which of the following is NOT a component of a typical hollow-fiber module?
reverse osmosis membrane
process recovery is typically ________ percent fr surface and can be as high as _________ percent.
95;97
in a typical reverse osmosis flow schematic, which of the following components most closely follows the
cartridge filter?
high-pressure pump
what process is defined as the ratio of the volume of product water, or permeate produced, to raw
water treated?
recovery
what term describes the raw water that has undergone pretreatment (acidification or scale inhibitor
addition) prior to entering the membrane arrays?
feedwater
in the precipitative softening plant, what percentage of solids sludge is produced?
5%
which sludge disposal method is most economical for lime-soda ash softening plants?
lagoons
what process is used to concentrate sludge?
thickener
what process is used to dewater sludge?
sand bed
in a rectangular basin, which type of collector uses suction pipes or a submersible pump to withdraw the
sludge from the basin?
floating-bridge siphon collector
in a drying bed, t sand I usually how deep?
3|Page
