FLORIDA WASTEWATER TEST PAPER 2025/2026
QUESTIONS AND ANSWERS RATED A+
✔✔Grit - ✔✔Consists of particulate materials in wastewater that have specific gravities
of approximately 2.65 and a temp of 15.5 deg. C; Consists of inorganic sand or gravel,
eggshells, bone fragments, fruit and vegetable pieces and seeds, and coffee grounds;
Primarily removed to prevent abrasion of piping and mechanical equipment;
✔✔Aerated Grit Chamber - ✔✔An chamber in which air is inroduced along one side of
the tank providing a helical flow pattern; Enables grit to settle while keeping the smaller
organic material suspended; Also keeps wastewater fresh by adding oxygen; Normally
designed to remove particles of at least .21 mm; Detention time ranges from 2-5
minutes; Air flow rates range from .2-.5 m^3 of air/min/length of tank;
✔✔Grit Removal in Horizontal-Flow Systems - ✔✔Removed through sedimentation by
gravity (Use Stoke's Law or Newton's Law);
✔✔Stoke's Law - ✔✔F_d=6(pi)(nu)(R)(v_s); Where F_d is the frictional force opposing
gravity in (N); (nu) is the dynamic viscosity in (N*s/m^2); R is the radius of the
particulate in (m); (v_s) is the settling velocity in (m/s);
✔✔Flotation - ✔✔The opposite of sedimentation; Utilizes buoyancy to separate solid
particles such as fats, oils, and greases, which cannot be removed through
sedimentation; Accomplished by introducing air at the bottom of a flotation tank;
✔✔FOG - ✔✔Fats, Oils, and Greases; DO NOT have to be part of wastewater stream;
CAN be easily converted into biodiesel and used to generate energy when combined
with digester gas; Or can be used as a supplementary fuel in solid-waste-to-energy
plants;
✔✔Flow-Equalization - ✔✔Implemented to dampen the flow and organic loading rate to
a wastewater treatment facility; Correct for large variations in flow; Can overcome
operational problems associated with large flow variations and improve the performance
of the downstream unit processes.
✔✔In-Line Equalization - ✔✔The process where all the flow pases through the
equalization basin; Has a impact on reducing BOD loading; Is typically used when
stringent dampening of both the flow and organic loading is required;
✔✔Off-Line Equalization - ✔✔The process where only a portion of the flow is diverted
through the equalization basin; Requires that the diverted flow be pumped and mixed
with the plant influent when the influent flow rate to the plant is reduced; Does not
reduce BOD loading as well as in-line Equalization
, ✔✔Equalization Storage Volume - ✔✔Determined by through analysis of cumulative
influent volume and cumulative average influent volume; The cumulative average
influent volume has a steadily increasing rate as it is simply total influent volume/time
period. However, the instanteous rate of inflow (simply, cumulative influent volume), has
two similar end points with average volume (start and end of time period) but varies with
time of day. Tank size is the maximum variation in cumulative inflow volume between
the two.
✔✔Primary Treatment - ✔✔Goal of involved processes is to remove solids through
quiescent (gravity settling); Typically, domestic wastewater is held for a period of ~2
hours; Removes 60% of suspended solids, 30% of BOD, and 20% of Phosphorus;
Removed BOD and Phosphorus are in particulate phase (part of TSS); Coagulants can
be added to improve the removal of particulate matter;
✔✔Settling Tanks - ✔✔Also referred to as Sedimentation Tanks or Clarifiers; Can be
rectangular or circular;
✔✔Sedimentation - ✔✔Solids settle to the bottom of the settling tank where they are
collected as a liquid-solid sludge;
✔✔TSS - ✔✔Total Suspended Solids
✔✔Coagulants in Primary Treatment - ✔✔Added to improve the removal of particulate
matter; May reduce the overall energy costs required during secondary treatment to
biologically convert these particles to CO2, water, and new biomass;
✔✔Primary Sludge - ✔✔Removed during Primary Treatment settling and segregated for
further treatment; Is malodorous, may contain pathogenic organisms, and has a high
water content (perhaps<1% solids); Difficult to dispose of;
✔✔Secondary Treatment - ✔✔A form of biological treatment that utilizes
microorganisms to decompose high energy molecules (abundance of Organic Matter -
Measured as BOD) of outflow from primary clarifiers; Two approaches: Suspended-
Growth Reactors and Attached-Growth Reactors;
✔✔Suspended-Growth Reactors - ✔✔Form of biological (secondary) treatment of
wastewater where microorganisms and wastewater are mixed together;
✔✔Attached-Growth Reactors - ✔✔Form of biological (secondary) treatment of
wastewater where microorganisms are attached to a support structure and wastewater
is passed over the organisms;
✔✔Aeration Tank - ✔✔A Completed Mixed Flow Reactor (CMFR); Site for Biological
(Secondary) Treatment; The majority of BOD is degraded in the presence of oxygen so
air is added to the reactor to supply oxygen; The air must be transferred to the aqueous
QUESTIONS AND ANSWERS RATED A+
✔✔Grit - ✔✔Consists of particulate materials in wastewater that have specific gravities
of approximately 2.65 and a temp of 15.5 deg. C; Consists of inorganic sand or gravel,
eggshells, bone fragments, fruit and vegetable pieces and seeds, and coffee grounds;
Primarily removed to prevent abrasion of piping and mechanical equipment;
✔✔Aerated Grit Chamber - ✔✔An chamber in which air is inroduced along one side of
the tank providing a helical flow pattern; Enables grit to settle while keeping the smaller
organic material suspended; Also keeps wastewater fresh by adding oxygen; Normally
designed to remove particles of at least .21 mm; Detention time ranges from 2-5
minutes; Air flow rates range from .2-.5 m^3 of air/min/length of tank;
✔✔Grit Removal in Horizontal-Flow Systems - ✔✔Removed through sedimentation by
gravity (Use Stoke's Law or Newton's Law);
✔✔Stoke's Law - ✔✔F_d=6(pi)(nu)(R)(v_s); Where F_d is the frictional force opposing
gravity in (N); (nu) is the dynamic viscosity in (N*s/m^2); R is the radius of the
particulate in (m); (v_s) is the settling velocity in (m/s);
✔✔Flotation - ✔✔The opposite of sedimentation; Utilizes buoyancy to separate solid
particles such as fats, oils, and greases, which cannot be removed through
sedimentation; Accomplished by introducing air at the bottom of a flotation tank;
✔✔FOG - ✔✔Fats, Oils, and Greases; DO NOT have to be part of wastewater stream;
CAN be easily converted into biodiesel and used to generate energy when combined
with digester gas; Or can be used as a supplementary fuel in solid-waste-to-energy
plants;
✔✔Flow-Equalization - ✔✔Implemented to dampen the flow and organic loading rate to
a wastewater treatment facility; Correct for large variations in flow; Can overcome
operational problems associated with large flow variations and improve the performance
of the downstream unit processes.
✔✔In-Line Equalization - ✔✔The process where all the flow pases through the
equalization basin; Has a impact on reducing BOD loading; Is typically used when
stringent dampening of both the flow and organic loading is required;
✔✔Off-Line Equalization - ✔✔The process where only a portion of the flow is diverted
through the equalization basin; Requires that the diverted flow be pumped and mixed
with the plant influent when the influent flow rate to the plant is reduced; Does not
reduce BOD loading as well as in-line Equalization
, ✔✔Equalization Storage Volume - ✔✔Determined by through analysis of cumulative
influent volume and cumulative average influent volume; The cumulative average
influent volume has a steadily increasing rate as it is simply total influent volume/time
period. However, the instanteous rate of inflow (simply, cumulative influent volume), has
two similar end points with average volume (start and end of time period) but varies with
time of day. Tank size is the maximum variation in cumulative inflow volume between
the two.
✔✔Primary Treatment - ✔✔Goal of involved processes is to remove solids through
quiescent (gravity settling); Typically, domestic wastewater is held for a period of ~2
hours; Removes 60% of suspended solids, 30% of BOD, and 20% of Phosphorus;
Removed BOD and Phosphorus are in particulate phase (part of TSS); Coagulants can
be added to improve the removal of particulate matter;
✔✔Settling Tanks - ✔✔Also referred to as Sedimentation Tanks or Clarifiers; Can be
rectangular or circular;
✔✔Sedimentation - ✔✔Solids settle to the bottom of the settling tank where they are
collected as a liquid-solid sludge;
✔✔TSS - ✔✔Total Suspended Solids
✔✔Coagulants in Primary Treatment - ✔✔Added to improve the removal of particulate
matter; May reduce the overall energy costs required during secondary treatment to
biologically convert these particles to CO2, water, and new biomass;
✔✔Primary Sludge - ✔✔Removed during Primary Treatment settling and segregated for
further treatment; Is malodorous, may contain pathogenic organisms, and has a high
water content (perhaps<1% solids); Difficult to dispose of;
✔✔Secondary Treatment - ✔✔A form of biological treatment that utilizes
microorganisms to decompose high energy molecules (abundance of Organic Matter -
Measured as BOD) of outflow from primary clarifiers; Two approaches: Suspended-
Growth Reactors and Attached-Growth Reactors;
✔✔Suspended-Growth Reactors - ✔✔Form of biological (secondary) treatment of
wastewater where microorganisms and wastewater are mixed together;
✔✔Attached-Growth Reactors - ✔✔Form of biological (secondary) treatment of
wastewater where microorganisms are attached to a support structure and wastewater
is passed over the organisms;
✔✔Aeration Tank - ✔✔A Completed Mixed Flow Reactor (CMFR); Site for Biological
(Secondary) Treatment; The majority of BOD is degraded in the presence of oxygen so
air is added to the reactor to supply oxygen; The air must be transferred to the aqueous
