PMT 108 PRINCIPLES OF WATER TEST 4 EXAM
Q&A 2026 STUDY GUIDE FULL SOLUTION
GRADED A+
◉ Stabilization. Answer: Use of treatment process to render domestic
wastewater residuals less odorous or putrescible
REDUCES PATHOGEN CONTENT
◉ Sludge. Answer: Residual, semi-solid material left from industrial
wastewater or sewage treatment
◉ Thickening. Answer: Process to increase the sludges concentration
and decrease sludges volume by removing some free water so that
sludge remains in fluid state
◉ Dewatering. Answer: Process of natural or mechanical removal of
water from sludge during which sludge is losing its fluidity
Becomes a damp solid and is transported in bulk
◉ Biosolids. Answer: Nutrient rich organic materials derived from
wastewater solids that have been stabilized through processing and
meets us epa or other applicable criteria for use
,◉ Sludge treatment
Primary treatment of domestic wastewater creates sludge
Contains approximately...percent organic material. Answer: 65 percent
◉ Secondary treatment sludge contains about...percent organic material.
Answer: 90 percent
◉ The intention of sludge digestion is to convert the bulky odorous and
putrescible waste into.... Answer: A well digested sludge which can be
easily dewatered and is odor free
◉ Digestion. Answer: Process by which solids generated in primary and
secondary sedimentation basins are stabilized and dewatered
◉ Digestion occurs at almost any temp, best range is.... Answer: 85-95
◉ Aerobic digestion. Answer: Biological oxidation of organic sludge
under aerobic conditions
◉ Anaerobic digestion. Answer: Biochem breakdown of organic solids
in the absence of free oxygen
Anaerobic microbes convert sludge into oxidized materials, new cells,
and gas
, ◉ Thickening. Answer: Continuous stirring for 6-24 hours which draws
off gas bubbles and supernatant
DOUBLES THE THICKNESS OF SLUDGE
◉ Elutriation. Answer: Sludge is washed with water or plants effluent
and chemicals to reduce alkalinity
◉ Chemical coagulation. Answer: Chemical coagulants are added to
enhance the release of water from solids during next step
◉ Dewatering. Answer: Reduces the moisture content of the sludge so
that it can easily be disposed of by landfill, incineration, heat drying,
etc...
Objective is moisture content of 60-80 percent
◉ Belt press filtration. Answer: Belt filter presses employ single or
double moving belts to continuously dewater sludge through one or
more stages of dewatering
◉ Sludge drying beds. Answer: Rely on drainage and evaporation to
effect moisture reduction
Q&A 2026 STUDY GUIDE FULL SOLUTION
GRADED A+
◉ Stabilization. Answer: Use of treatment process to render domestic
wastewater residuals less odorous or putrescible
REDUCES PATHOGEN CONTENT
◉ Sludge. Answer: Residual, semi-solid material left from industrial
wastewater or sewage treatment
◉ Thickening. Answer: Process to increase the sludges concentration
and decrease sludges volume by removing some free water so that
sludge remains in fluid state
◉ Dewatering. Answer: Process of natural or mechanical removal of
water from sludge during which sludge is losing its fluidity
Becomes a damp solid and is transported in bulk
◉ Biosolids. Answer: Nutrient rich organic materials derived from
wastewater solids that have been stabilized through processing and
meets us epa or other applicable criteria for use
,◉ Sludge treatment
Primary treatment of domestic wastewater creates sludge
Contains approximately...percent organic material. Answer: 65 percent
◉ Secondary treatment sludge contains about...percent organic material.
Answer: 90 percent
◉ The intention of sludge digestion is to convert the bulky odorous and
putrescible waste into.... Answer: A well digested sludge which can be
easily dewatered and is odor free
◉ Digestion. Answer: Process by which solids generated in primary and
secondary sedimentation basins are stabilized and dewatered
◉ Digestion occurs at almost any temp, best range is.... Answer: 85-95
◉ Aerobic digestion. Answer: Biological oxidation of organic sludge
under aerobic conditions
◉ Anaerobic digestion. Answer: Biochem breakdown of organic solids
in the absence of free oxygen
Anaerobic microbes convert sludge into oxidized materials, new cells,
and gas
, ◉ Thickening. Answer: Continuous stirring for 6-24 hours which draws
off gas bubbles and supernatant
DOUBLES THE THICKNESS OF SLUDGE
◉ Elutriation. Answer: Sludge is washed with water or plants effluent
and chemicals to reduce alkalinity
◉ Chemical coagulation. Answer: Chemical coagulants are added to
enhance the release of water from solids during next step
◉ Dewatering. Answer: Reduces the moisture content of the sludge so
that it can easily be disposed of by landfill, incineration, heat drying,
etc...
Objective is moisture content of 60-80 percent
◉ Belt press filtration. Answer: Belt filter presses employ single or
double moving belts to continuously dewater sludge through one or
more stages of dewatering
◉ Sludge drying beds. Answer: Rely on drainage and evaporation to
effect moisture reduction
