WASTE WATER GRADE 1 |3 DIFFERENT
VERSIONS FINAL TEST 2026 QUESTIONS
WITH CORRECT ANSWERS GRADED A+
◍ Vs in anaerobic digester is reduced by.
Answer: Acid formers and methane formers
◍ Thermal valve.
Answer: A fusible element which melts at 260 f when exposed to a flame,
causes a thermal valve to close shutting off the flow of gas. These valves
may be attached to a flame arrester. These valves should be serviced at least
once a year.
◍ Humus.
Answer: Offensive organic matter that is stabilized in the digester
◍ Algae.
Answer: Without light algae use o2 and produce co2. Light only reaches
about three feet depth.
◍ E.
Answer: Lbs per day of TSS unintentionally lost in effulgent
◍ Two types of grit removal.
Answer: Velocity controlled grit chambers, aerated grit chambers.
◍ Detention time of pond.
Answer: 30 to 60 days or longer. DT= A x depth/Q
◍ Acetogenesis.
Answer: Formation of volatile acids
◍ Acid formers.
Answer: Converts part of the complex organic mixture in the influent sludge
, stream into volatile acids( organic acids) including acetic, propionic, and
butyric acids
◍ grab sample.
Answer: One time sample. Chlorine residual, coliform tests, settable solids,
dissolved oxygen, pH, grease and oil, sulfide tests.
◍ Time based composite sample.
Answer: Fixed volume of sample is collected after passage of a set amount
of time over a certain time period.
◍ Niosh limit for chlorine.
Answer: 10 ppm
◍ How to fix WAS flow rate to achieve optimal sludge quality....
Answer: Maintain constant mlss or moves conc or mass, maintain a constant
mcrt, maintain constant food to microorganism ratio.
◍ Settleable solids.
Answer: All settleable solids are TSS but not all TSS are settleable.
◍ WAS flow rate controls .....
Answer: Nitrification, mlss conc, sludge quality, effluent quality, secondary
clarifier capacity, secondary clarifier sludge blanket depth, oxygen
requirements , occurrence of some foam causing organisms.
◍ diurnal flow.
Answer: Low at night between 2 and 5 am, steady steep increase in flow
starting after 5 am, reaching first peak in the late morning or early afternoon,
slight decrease through the afternoon, second peak between 6 and 9 pm, and
a tapering off of to the low flows of 2 am.
◍ Mixing digesters.
Answer: Gas lift or mechanical mixing using pumps or propeller type mixers
are common methods to mix. Centrifugal pumps are becoming more
common.
◍ Activate sludge treatment plant important aspects of operation.
VERSIONS FINAL TEST 2026 QUESTIONS
WITH CORRECT ANSWERS GRADED A+
◍ Vs in anaerobic digester is reduced by.
Answer: Acid formers and methane formers
◍ Thermal valve.
Answer: A fusible element which melts at 260 f when exposed to a flame,
causes a thermal valve to close shutting off the flow of gas. These valves
may be attached to a flame arrester. These valves should be serviced at least
once a year.
◍ Humus.
Answer: Offensive organic matter that is stabilized in the digester
◍ Algae.
Answer: Without light algae use o2 and produce co2. Light only reaches
about three feet depth.
◍ E.
Answer: Lbs per day of TSS unintentionally lost in effulgent
◍ Two types of grit removal.
Answer: Velocity controlled grit chambers, aerated grit chambers.
◍ Detention time of pond.
Answer: 30 to 60 days or longer. DT= A x depth/Q
◍ Acetogenesis.
Answer: Formation of volatile acids
◍ Acid formers.
Answer: Converts part of the complex organic mixture in the influent sludge
, stream into volatile acids( organic acids) including acetic, propionic, and
butyric acids
◍ grab sample.
Answer: One time sample. Chlorine residual, coliform tests, settable solids,
dissolved oxygen, pH, grease and oil, sulfide tests.
◍ Time based composite sample.
Answer: Fixed volume of sample is collected after passage of a set amount
of time over a certain time period.
◍ Niosh limit for chlorine.
Answer: 10 ppm
◍ How to fix WAS flow rate to achieve optimal sludge quality....
Answer: Maintain constant mlss or moves conc or mass, maintain a constant
mcrt, maintain constant food to microorganism ratio.
◍ Settleable solids.
Answer: All settleable solids are TSS but not all TSS are settleable.
◍ WAS flow rate controls .....
Answer: Nitrification, mlss conc, sludge quality, effluent quality, secondary
clarifier capacity, secondary clarifier sludge blanket depth, oxygen
requirements , occurrence of some foam causing organisms.
◍ diurnal flow.
Answer: Low at night between 2 and 5 am, steady steep increase in flow
starting after 5 am, reaching first peak in the late morning or early afternoon,
slight decrease through the afternoon, second peak between 6 and 9 pm, and
a tapering off of to the low flows of 2 am.
◍ Mixing digesters.
Answer: Gas lift or mechanical mixing using pumps or propeller type mixers
are common methods to mix. Centrifugal pumps are becoming more
common.
◍ Activate sludge treatment plant important aspects of operation.
