PSE 322 EXAM STUDY SET 2025/2026
What two classes of additives, which are often used to pretreat wastewater before a
primary clarifier, play similar roles to additives used on the paper machine? - ANSWER
Coagulants and flocculants
What type of secondary treatment of wastewater does not employ aeration? - ANSWER
Anaerobic
What test of wastewater (treated and untreated) provides a quick way to estimate the
biological oxygen demand? - ANSWER COD
Which of the following membrane types is the most exclusive, mainly just allowing water
to pass? - ANSWER Reverse osmosis
What trend within paper mill systems has tended to increase the levels of salt ions with
the passage of years? - ANSWER Decreased fresh water used per ton of product
What word could be used to describe something that is capable of being broken down
by bacteria, etc., in the environment so that it does not accumulate? - ANSWER
Biodegradable
Why is some long fiber added to process water being sent to a disc save-all? - ANSWER
It acts as a filter medium.
What is the purpose of a gravity strainer installed after a disc save-all system? -
ANSWER Help prepare solids-free water for showers.
According to the US EPA, what is a life cycle assessment (LCA)? - ANSWER A concept
and methodology to evaluate the environmental effects of a product or activity
holistically, by evaluating the whole life cycle of a particular product, process, or
activity
Why is it difficult to find alternative value-added uses for residuals from pulp and paper
operations? - ANSWER Presence of impurities
What three steps do papermakers mainly typically take to minimize the amount of solids
discharged from the mill to a natural waterway? - ANSWER Retention aid use, save-all
use, clarifier use
Of the following, which is the largest contribution to energy that is then consumed for
various purposes such as the drying of paper a typical kraft pulp and paper mill? -
ANSWER Spent pulp liquors
What is the main goal of secondary wastewater treatment using activated sludge? -
ANSWER Consume biological oxygen demand
,An excess of starch in water discharged from a paper mill will contribute to what in the
wastewater? - ANSWER BOD
What is the meaning of the letters "TSS" in terms of wastewater quality? - ANSWER Total
suspended solids
What is the main concern about the environmental impact of some presently used
greaseproof products? - ANSWER INCORRECT
Slower biodegradation than polyethylene
In a compact bioreactor, as might be considered for installation within a paper machine
system, what could be the likely purpose of floating plastic disks having hollow spaces
in them? - ANSWER Allow bacteria to acclimate and to inoculate incoming process
water with bacteria.
Why can kidney technologies be important when a mill management has made a
commitment to run with zero liquid effluent? - ANSWER Highly soluble substances such
as salts otherwise can build up to high levels and cause problems.
What can involve resource extraction, design, manufacture, distribution, use, collection,
all followed by reuse, recycling, energy conversion, or disposal? - ANSWER Life cycle
assessment
What aspect of cellulose makes it possible for a dense layer of dry nanocellulose to
effectively block oxygen more effectively than a similar thickness of polyethylene? -
ANSWER High cohesive energy density due to hydrogen bonding
Chlorinated aromatic compounds would fall into which category of pollutant? - ANSWER
AOX
What is a likely source of algal blooms, anaerobic conditions, fish die-offs, and odors? -
ANSWER Biodegradable substances added to water
An upflow sludge blanket reactor produces what as a byproduct? - ANSWER Biogas,
which includes methane
What favorable outcome is caused by raking, screw press, or a belt filter press? -
ANSWER Higher sludge solids
What is the function of a "skimmer" in a clarifier system for wastewater treatment? -
ANSWER Remove floating scum and foam
Why do filtration membranes (e.g. ultrafiltration) typically show declining rates of
permeability with time of usage in an industrial process? - ANSWER Pore blockages and
filter cake buildup
In the US, when using perfluorochemical to make greaseproof paper products, what is
the maximum carbon chain length? - ANSWER Six
,What liquids are used in the mixtures for the carrying out of "kit" tests for greaseproof
paper? - ANSWER Caster oil, toluene, heptane
In modern papermaking systems there is increased reliance on oxidants (e.g. H2O2 or
ClO2) and enzymatic treatments to that there is less need to employ what? - ANSWER
Toxic organic compounds that serve as biocides
Why is the presence of crystalline domains within cellulose (including within
nanofibrillated cellulose) regarded as an inherent advantage when the goal is to provide
a barrier to oxygen or grease? - ANSWER The diffusing molecules would have to go
around each crystal.
What is the meaning of the letters "BOD" in terms of wastewater quality? - ANSWER
Biological oxygen demand
Which of the following tests estimates the complete amount of organic compounds,
based on their carbon content? - ANSWER TOC
What is the device in which coagulation and settling occur during wastewater
treatment? - ANSWER Clarifier
Which operation used in processing of sludge from wastewater resembles a "gap
former" type of paper machine in key respects? - ANSWER Belt filter press
When papermakers want a product to be able to resist passage of contrasting types of
substances, e.g. both water and air, what is the most common approach taken in
product development? - ANSWER Use of layers
What component of wet-strength resin systems intended to cure under acidic conditions
is now either avoided or minimized due to its health issues? - ANSWER Formaldehyde
Which of the following approaches represents a realistic way to reduce the amount of
fresh water used in papermaking? - ANSWER Replace fresh water used in paper
machine showers with water from the save-all discharge that then passes through a
gravity strainer and canister filters.
What can papermakers do to reduce costs associated with heating of water and or
treating the liquid effluent from the papermaking process? - ANSWER Recirculation of
more of the process water, reducing the need for fresh water.
Agglomeration deinking is well suited for deinking of what kind of wastepaper? -
ANSWER Xerographic prints
Why does a proportion of the mass of recovered paper arriving at a paper recycling mill
end up as sludge? - ANSWER The recycling process removes contaminants such as
plastic and ink, etc. Some fibers wind up as part of the rejects.
What key step in deinking often gets achieved in the pulper? - ANSWER Detachment of
ink particles from fibers
, What kind of problems in the paper mill can result from the presence of
ethylene-vinylacetate (EVA)? - ANSWER Stickies
What type of papermaking additive is most effective when used at a temperature slightly
below the cloud point of its active ingredient? - ANSWER Defoamer
In what way do high-yield fibers, such as TMP, differ from kraft fibers? - ANSWER Their
bonding ability is not hurt significantly by paper recycling.
What is the name for an organic compound that can surround a metal ion with multiple
carboxylic acid groups to form a strong complex? - ANSWER Chelating agent
Which of the following tests is very simple to measure and can be a warning sign of
upsets, such as increased carry-over of contaminants from kraft pulping? - ANSWER
Electrical conductivity
When implementing an online retention control system, what quantity is usually
monitored? - ANSWER White water solids
What type of consistency sensing equipment has no moving parts? - ANSWER
Microwave
What type of printing employs plastic binder that is heated to its melting point during
printing? - ANSWER Xerography
Which of the following types of pulp is susceptible to alkaline darkening if exposed to
high pH? - ANSWER High yield pulp (e.g. ONP)
In a DAF unit, why does the dissolved air become transformed into small bubbles when it
enters a flotation unit? - ANSWER Decreased pressure
The washing unit operation is especially effective for removal of what kind of printing
ink? - ANSWER Flexo
What is a "collector chemical" used for? - ANSWER Flotation deinking
What two classes of additives, which are often used to pretreat wastewater before a
primary clarifier, play similar roles to additives used on the paper machine? - ANSWER
Coagulants and flocculants
What type of secondary treatment of wastewater does not employ aeration? - ANSWER
Anaerobic
What test of wastewater (treated and untreated) provides a quick way to estimate the
biological oxygen demand? - ANSWER COD
Which of the following membrane types is the most exclusive, mainly just allowing water
to pass? - ANSWER Reverse osmosis
What trend within paper mill systems has tended to increase the levels of salt ions with
the passage of years? - ANSWER Decreased fresh water used per ton of product
What word could be used to describe something that is capable of being broken down
by bacteria, etc., in the environment so that it does not accumulate? - ANSWER
Biodegradable
Why is some long fiber added to process water being sent to a disc save-all? - ANSWER
It acts as a filter medium.
What is the purpose of a gravity strainer installed after a disc save-all system? -
ANSWER Help prepare solids-free water for showers.
According to the US EPA, what is a life cycle assessment (LCA)? - ANSWER A concept
and methodology to evaluate the environmental effects of a product or activity
holistically, by evaluating the whole life cycle of a particular product, process, or
activity
Why is it difficult to find alternative value-added uses for residuals from pulp and paper
operations? - ANSWER Presence of impurities
What three steps do papermakers mainly typically take to minimize the amount of solids
discharged from the mill to a natural waterway? - ANSWER Retention aid use, save-all
use, clarifier use
Of the following, which is the largest contribution to energy that is then consumed for
various purposes such as the drying of paper a typical kraft pulp and paper mill? -
ANSWER Spent pulp liquors
What is the main goal of secondary wastewater treatment using activated sludge? -
ANSWER Consume biological oxygen demand
,An excess of starch in water discharged from a paper mill will contribute to what in the
wastewater? - ANSWER BOD
What is the meaning of the letters "TSS" in terms of wastewater quality? - ANSWER Total
suspended solids
What is the main concern about the environmental impact of some presently used
greaseproof products? - ANSWER INCORRECT
Slower biodegradation than polyethylene
In a compact bioreactor, as might be considered for installation within a paper machine
system, what could be the likely purpose of floating plastic disks having hollow spaces
in them? - ANSWER Allow bacteria to acclimate and to inoculate incoming process
water with bacteria.
Why can kidney technologies be important when a mill management has made a
commitment to run with zero liquid effluent? - ANSWER Highly soluble substances such
as salts otherwise can build up to high levels and cause problems.
What can involve resource extraction, design, manufacture, distribution, use, collection,
all followed by reuse, recycling, energy conversion, or disposal? - ANSWER Life cycle
assessment
What aspect of cellulose makes it possible for a dense layer of dry nanocellulose to
effectively block oxygen more effectively than a similar thickness of polyethylene? -
ANSWER High cohesive energy density due to hydrogen bonding
Chlorinated aromatic compounds would fall into which category of pollutant? - ANSWER
AOX
What is a likely source of algal blooms, anaerobic conditions, fish die-offs, and odors? -
ANSWER Biodegradable substances added to water
An upflow sludge blanket reactor produces what as a byproduct? - ANSWER Biogas,
which includes methane
What favorable outcome is caused by raking, screw press, or a belt filter press? -
ANSWER Higher sludge solids
What is the function of a "skimmer" in a clarifier system for wastewater treatment? -
ANSWER Remove floating scum and foam
Why do filtration membranes (e.g. ultrafiltration) typically show declining rates of
permeability with time of usage in an industrial process? - ANSWER Pore blockages and
filter cake buildup
In the US, when using perfluorochemical to make greaseproof paper products, what is
the maximum carbon chain length? - ANSWER Six
,What liquids are used in the mixtures for the carrying out of "kit" tests for greaseproof
paper? - ANSWER Caster oil, toluene, heptane
In modern papermaking systems there is increased reliance on oxidants (e.g. H2O2 or
ClO2) and enzymatic treatments to that there is less need to employ what? - ANSWER
Toxic organic compounds that serve as biocides
Why is the presence of crystalline domains within cellulose (including within
nanofibrillated cellulose) regarded as an inherent advantage when the goal is to provide
a barrier to oxygen or grease? - ANSWER The diffusing molecules would have to go
around each crystal.
What is the meaning of the letters "BOD" in terms of wastewater quality? - ANSWER
Biological oxygen demand
Which of the following tests estimates the complete amount of organic compounds,
based on their carbon content? - ANSWER TOC
What is the device in which coagulation and settling occur during wastewater
treatment? - ANSWER Clarifier
Which operation used in processing of sludge from wastewater resembles a "gap
former" type of paper machine in key respects? - ANSWER Belt filter press
When papermakers want a product to be able to resist passage of contrasting types of
substances, e.g. both water and air, what is the most common approach taken in
product development? - ANSWER Use of layers
What component of wet-strength resin systems intended to cure under acidic conditions
is now either avoided or minimized due to its health issues? - ANSWER Formaldehyde
Which of the following approaches represents a realistic way to reduce the amount of
fresh water used in papermaking? - ANSWER Replace fresh water used in paper
machine showers with water from the save-all discharge that then passes through a
gravity strainer and canister filters.
What can papermakers do to reduce costs associated with heating of water and or
treating the liquid effluent from the papermaking process? - ANSWER Recirculation of
more of the process water, reducing the need for fresh water.
Agglomeration deinking is well suited for deinking of what kind of wastepaper? -
ANSWER Xerographic prints
Why does a proportion of the mass of recovered paper arriving at a paper recycling mill
end up as sludge? - ANSWER The recycling process removes contaminants such as
plastic and ink, etc. Some fibers wind up as part of the rejects.
What key step in deinking often gets achieved in the pulper? - ANSWER Detachment of
ink particles from fibers
, What kind of problems in the paper mill can result from the presence of
ethylene-vinylacetate (EVA)? - ANSWER Stickies
What type of papermaking additive is most effective when used at a temperature slightly
below the cloud point of its active ingredient? - ANSWER Defoamer
In what way do high-yield fibers, such as TMP, differ from kraft fibers? - ANSWER Their
bonding ability is not hurt significantly by paper recycling.
What is the name for an organic compound that can surround a metal ion with multiple
carboxylic acid groups to form a strong complex? - ANSWER Chelating agent
Which of the following tests is very simple to measure and can be a warning sign of
upsets, such as increased carry-over of contaminants from kraft pulping? - ANSWER
Electrical conductivity
When implementing an online retention control system, what quantity is usually
monitored? - ANSWER White water solids
What type of consistency sensing equipment has no moving parts? - ANSWER
Microwave
What type of printing employs plastic binder that is heated to its melting point during
printing? - ANSWER Xerography
Which of the following types of pulp is susceptible to alkaline darkening if exposed to
high pH? - ANSWER High yield pulp (e.g. ONP)
In a DAF unit, why does the dissolved air become transformed into small bubbles when it
enters a flotation unit? - ANSWER Decreased pressure
The washing unit operation is especially effective for removal of what kind of printing
ink? - ANSWER Flexo
What is a "collector chemical" used for? - ANSWER Flotation deinking
