WASTEWATER TREATMENT
OPERATOR EXAM COMPREHENSIVE
FINAL PAPER QUESTIONS
SOLUTIONS GRADED A+
◉ conservative pollutants. Answer: metals. not altered by
microorganisms
◉ flow. Answer: report only
100gallons per day per person
◉ math p32. Answer:
◉ fecal coliform, e coli. Answer: colony count per 100ml
fecal coliform 200 monthly average, 400 maximum,
e coli 130 monthly average, 240 max
sterile container, grab sample, 6 hr holding time, sodium
thiosulphate to remove cl2
◉ DO. Answer: normal limit 7 mgl
in plant desired 2-4 mgl
must be calibrated
,◉ PH. Answer: measure of hydrogen ions in solution H+,
acidity or alkalinity of solution,
limits usually between 6-9
logrithmic, increase 10x per unit
◉ CL2. Answer: limit, monthly average .011 mgl, daily max .019 mgl
calibrated daily
◉ population loading. Answer: BOD .17
TSS .2
phos .0048
influent 100 gallons
◉ what is the preservative added to samples. Answer: sulfuric acid
to PH less than 2
◉ what acid used to preserve metal samples. Answer: nitric acid
◉ math p 38-40. Answer:
◉ synthesis. Answer: bugs take in BOD and make new cells
, ◉ respiration. Answer: The process by which cells break down
simple food molecules to release the energy they contain. Release
CO2 and water.
◉ activated sludge. Answer: affected by BOD, PH, DO,
mix of bacteria, protozoa, metazoa,
95% of sludge is bugs
◉ TOC. Answer: total organic carbons, normal range 200-250 mgl
measured by burning sample at 550c and measuring cabon dioxide
produced
◉ COD. Answer: chemical oxygen demand
550-700 mgl
amount of oxygen to completely oxidize to CO2 and water
◉ BOD. Answer: better measure of toxicity,
soft, simple, more easily degraded, 1-2 hrs
hard, complex, larger compounds may take hrs or days, attacked by
enzymes secreted by bacteria
◉ slime. Answer: enzymes secreted by bacteria, keeps food close,
and other bacteria close
OPERATOR EXAM COMPREHENSIVE
FINAL PAPER QUESTIONS
SOLUTIONS GRADED A+
◉ conservative pollutants. Answer: metals. not altered by
microorganisms
◉ flow. Answer: report only
100gallons per day per person
◉ math p32. Answer:
◉ fecal coliform, e coli. Answer: colony count per 100ml
fecal coliform 200 monthly average, 400 maximum,
e coli 130 monthly average, 240 max
sterile container, grab sample, 6 hr holding time, sodium
thiosulphate to remove cl2
◉ DO. Answer: normal limit 7 mgl
in plant desired 2-4 mgl
must be calibrated
,◉ PH. Answer: measure of hydrogen ions in solution H+,
acidity or alkalinity of solution,
limits usually between 6-9
logrithmic, increase 10x per unit
◉ CL2. Answer: limit, monthly average .011 mgl, daily max .019 mgl
calibrated daily
◉ population loading. Answer: BOD .17
TSS .2
phos .0048
influent 100 gallons
◉ what is the preservative added to samples. Answer: sulfuric acid
to PH less than 2
◉ what acid used to preserve metal samples. Answer: nitric acid
◉ math p 38-40. Answer:
◉ synthesis. Answer: bugs take in BOD and make new cells
, ◉ respiration. Answer: The process by which cells break down
simple food molecules to release the energy they contain. Release
CO2 and water.
◉ activated sludge. Answer: affected by BOD, PH, DO,
mix of bacteria, protozoa, metazoa,
95% of sludge is bugs
◉ TOC. Answer: total organic carbons, normal range 200-250 mgl
measured by burning sample at 550c and measuring cabon dioxide
produced
◉ COD. Answer: chemical oxygen demand
550-700 mgl
amount of oxygen to completely oxidize to CO2 and water
◉ BOD. Answer: better measure of toxicity,
soft, simple, more easily degraded, 1-2 hrs
hard, complex, larger compounds may take hrs or days, attacked by
enzymes secreted by bacteria
◉ slime. Answer: enzymes secreted by bacteria, keeps food close,
and other bacteria close
