Kentucky Wastewater Treatment Operator
Certification Study Guide | Operator
Practice Questions & Exam Prep
2026/2027
,absorption taking in substance into body of another
acid A substance that increases the hydrogen ion concentration of a solution.
lowers PH
corrosive
activated sludge produced in raw or settled wastewater by the growth of bacteria, in the presence of
dissolved oxygen.
activated sludge process A biological wastewater treatment process which speeds up the decomposition of
wastes in the wastewater being treated. Activated Sludge is added to wastewater
and the mixture (mixed liquor) is aerated and agitated. After some time in the
aeration tank, the activated sludge is allowed to settle out by sedimentation and is
disposed of (wasted) or reused (returned to the aeration tank) as needed, the
remaining wastewater then undergoes more treatment.
adsorption The process of binding or sticking to a surface.
advanced waste treatment Any process of water renovation that upgrades treated wastewater to meet specific
reuse requirements.
aeration the process by which air is circulated through, mixed with or dissolved in a liquid or
substance.
aerobes Bacteria that require oxygen to grow
aerobic bacteria bacteria that use oxygen for cellular respiration
air lift type of pump, air injected at the bottom to lift water to the top, like percolator coffee
pot
algae microscopic plants. live in or on water or on structures near water, make o2 during
day, use o2 at night, affect PH and DO
aliquot A portion of a well-mixed sample removed for testing
alkalinity ability of water to buffer acids
anaerobic Process that does not require oxygen
, anaerobic bacteria bacteria that do not require oxygen to survive
anaerobic digestion is the decomposition of waste under anaerobic conditions to produce biogas and a
compost-like residue
anoxic oxygen deficient less than .5 ppm
bacteria (microbiology) single-celled or noncellular spherical or spiral or rod-shaped
organisms lacking chlorophyll that reproduce by fission
baffle board used to direct flow, uniform velocities, absorb energy, divert, guide, agitate
liquids
base a compound that produces hydroxide ions in solution. raises PH
biomass the total mass of organisms in a given area or volume.
biosolids A primarily organic solid product produced by wastewater treatment processes that
can be beneficially recycled. The word biosolids is replacing the word sludge when
referring to treated waste.
Biochemical Oxygen Demand (BOD) A measure of the amount of dissolved oxygen required to break down the organic
material in a given volume of water through aerobic biological activity
blank sample being tested is not added
buffer A solution that minimizes changes in pH when extraneous acids or bases are added
to the solution.
bulking a condition arising when sludge floats rather than settles in secondary sewage
treatment. can be caused by filamentous bacteria
Carbonaceous Biochemical Oxygen Demand (CBOD) only the BOD required to remove carbon. based
cavitation formation and collapse of gas bubbles due to low pressure. can cause pitting.
makes noise.
centrifuge device to separate substances by spinning them at high speed
Certification Study Guide | Operator
Practice Questions & Exam Prep
2026/2027
,absorption taking in substance into body of another
acid A substance that increases the hydrogen ion concentration of a solution.
lowers PH
corrosive
activated sludge produced in raw or settled wastewater by the growth of bacteria, in the presence of
dissolved oxygen.
activated sludge process A biological wastewater treatment process which speeds up the decomposition of
wastes in the wastewater being treated. Activated Sludge is added to wastewater
and the mixture (mixed liquor) is aerated and agitated. After some time in the
aeration tank, the activated sludge is allowed to settle out by sedimentation and is
disposed of (wasted) or reused (returned to the aeration tank) as needed, the
remaining wastewater then undergoes more treatment.
adsorption The process of binding or sticking to a surface.
advanced waste treatment Any process of water renovation that upgrades treated wastewater to meet specific
reuse requirements.
aeration the process by which air is circulated through, mixed with or dissolved in a liquid or
substance.
aerobes Bacteria that require oxygen to grow
aerobic bacteria bacteria that use oxygen for cellular respiration
air lift type of pump, air injected at the bottom to lift water to the top, like percolator coffee
pot
algae microscopic plants. live in or on water or on structures near water, make o2 during
day, use o2 at night, affect PH and DO
aliquot A portion of a well-mixed sample removed for testing
alkalinity ability of water to buffer acids
anaerobic Process that does not require oxygen
, anaerobic bacteria bacteria that do not require oxygen to survive
anaerobic digestion is the decomposition of waste under anaerobic conditions to produce biogas and a
compost-like residue
anoxic oxygen deficient less than .5 ppm
bacteria (microbiology) single-celled or noncellular spherical or spiral or rod-shaped
organisms lacking chlorophyll that reproduce by fission
baffle board used to direct flow, uniform velocities, absorb energy, divert, guide, agitate
liquids
base a compound that produces hydroxide ions in solution. raises PH
biomass the total mass of organisms in a given area or volume.
biosolids A primarily organic solid product produced by wastewater treatment processes that
can be beneficially recycled. The word biosolids is replacing the word sludge when
referring to treated waste.
Biochemical Oxygen Demand (BOD) A measure of the amount of dissolved oxygen required to break down the organic
material in a given volume of water through aerobic biological activity
blank sample being tested is not added
buffer A solution that minimizes changes in pH when extraneous acids or bases are added
to the solution.
bulking a condition arising when sludge floats rather than settles in secondary sewage
treatment. can be caused by filamentous bacteria
Carbonaceous Biochemical Oxygen Demand (CBOD) only the BOD required to remove carbon. based
cavitation formation and collapse of gas bubbles due to low pressure. can cause pitting.
makes noise.
centrifuge device to separate substances by spinning them at high speed
