Category: WASTE WATER Engineering Objective Questions

250+ TOP MCQs on Phosphorus Removal – 2 and Answers

Waste Water Engineering Assessment Questions and Answers on “Phosphorus Removal – 2”.

1. What is the retention time considered for the anaerobic zone for the AO process for removing phosphorus?
a) 0.5-1.5 hrs
b) 1.5-2 hrs
c) 2-4 hrs
d) 4-8 hrs
Answer: a
Clarification: The retention time considered for the anaerobic zone for the AO process for removing phosphorus is 0.5-1.5 hrs. This process involves aerobic oxidation followed by anaerobic digestion. This is a very effective method to remove phosphorus compounds.

2. What is the retention time considered for the aerobic zone for the AO process for removing phosphorus?
a) 1-3 hrs
b) 3-5 hrs
c) 5-8 hrs
d) 8-11 hrs
Answer: a
Clarification: The retention time considered for the aerobic zone for the AO process for removing phosphorus is 1-3 hrs. This process involves aerobic oxidation followed by anaerobic digestion. This is a very effective method to remove phosphorus compounds.

3. What is the retention time considered for the anaerobic zone for the A2O process for removing phosphorus?
a) 0.5-1.5 hrs
b) 1.5-2 hrs
c) 5-7 hrs
d) 3-4 hrs
Answer: a
Clarification: The retention time considered for the anaerobic zone for the A2O process for removing phosphorus is 0.5-1.5 hrs. This process is a modification process of the AO process. This is a very effective method to remove phosphorus compounds.

4. What is the retention time considered for the aerobic zone for the A2O process for removing phosphorus?
a) 0.5-1.5 hrs
b) 1.5-3 hrs
c) 3-4 hrs
d) 4-8 hrs
Answer: d
Clarification: The retention time considered for the aerobic zone for the A2O process for removing phosphorus is 4-8 hrs. This process is a modification process of the AO process. This is a very effective method to remove phosphorus compounds.

5. What is the retention time considered for the anoxic zone for the A2O process for removing phosphorus?
a) 0.5-1 hrs
b) 1-2 hrs
c) 2-4 hrs
d) 4-6 hrs
Answer: a
Clarification: The retention time considered for the anoxic zone for the A2O process for removing phosphorus is 0.5-1 hrs. This process is a modification process of the AO process. This is a very effective method to remove phosphorus compounds.

6. What is the retention time considered for the anoxic zone for the University of Cape Town treatment process for removing phosphorus?
a) 2-4 hrs
b) 4-6 hrs
c) 6-8 hrs
d) 8-10 hrs
Answer: a
Clarification: The retention time considered for the anoxic zone for the University of Cape Town treatment process for removing phosphorus is 2-4 hrs. The MLSS level maintained is 3000-4000 mg/L. The internal recirculation considered is 200-400%.

7. What is the retention time considered for the anaerobic zone for the University of Cape Town treatment process for removing phosphorus?
a) 1-2 hrs
b) 3-4 hrs
c) 4-8 hrs
d) 8-12 hrs
Answer: a
Clarification: The retention time considered for the anaerobic zone for the University of Cape Town treatment process for removing phosphorus is 1-2 hrs. The MLSS level maintained is 3000-4000 mg/L. The internal recirculation considered is 200-400%.

8. What is the retention time considered for the aerobic zone for the University of Cape Town treatment process for removing phosphorus?
a) 4-12 hrs
b) 3-4 hrs
c) 1-2 hrs
d) 5-6 hrs
Answer: a
Clarification: The retention time considered for the aerobic zone for the University of Cape Town treatment process for removing phosphorus is 4-12 hrs. The MLSS level maintained is 3000-4000 mg/L. The internal recirculation considered is 200-400%.

9. What is the retention time considered for the aerobic zone for the Virginia Initiative Plant treatment process for removing phosphorus?
a) 4-6 hrs
b) 10-12 hrs
c) 2-4 hrs
d) 1-2 hrs
Answer: a
Clarification: The retention time considered for the aerobic zone for the Virginia Initiative Plant treatment process for removing phosphorus is 4-6 hrs. The MLSS level maintained is 2000-4000 mg/L. The internal recirculation considered is 100-200% for the anoxic tank.

10. What is the retention time considered for the aerobic zone for the Virginia Initiative Plant treatment process for removing phosphorus?
a) 3-5 hrs
b) 7-9 hrs
c) 1-2 hrs
d) 4-6 hrs
Answer: c
Clarification: The retention time considered for the anaerobic zone for the Virginia Initiative Plant treatment process for removing phosphorus is 1-2 hrs. The MLSS level maintained is 2000-4000 mg/L. The internal recirculation considered is 100-200% for the anoxic tank.

Waste Water Engineering Assessment Questions,

250+ TOP MCQs on Ion Exchange Media Properties – 2 and Answers

Tough Waste Water Engineering Questions and Answers on “Ion Exchange Media Properties – 2”.

1. What is the SAC resin made up of?
a) Styrene and vinyl benzene
b) Divinyl benzene
c) Benzene and styrene
d) Styrene and divinyl benzene
Answer: d
Clarification: The SAC resin is made up of styrene and divinyl benzene. The functional group is sulphonic acid. These resins maybe gel or macro porous in nature.

2. In a SAC resin, what is the preferred cross linking?
a) 6-8%
b) 8-10%
c) 10-12%
d) 12-14%
Answer: a
Clarification: Usually SAC resins with 6-8% cross-linking divinyl benzene is used. This resin is used to remove alkalinity, EMA and CO2. In case of no degassed this is used to remove CO2.

3. What is the WAC resin made up of?
a) Polyacrylic acid
b) Polyacrylic acid with a carboxylic acid functional group
c) Acrylic acid with a carboxylic acid functional group
d) Acrylic acid
Answer: b
Clarification: The WAC resin constitutes the Polyacrylic acid with a carboxylic acid functional group. This resin removes alkalinity. This resin also removes hardness.

4. Which type of character does the strong basic acid type I have?
a) High basicity
b) Low basicity
c) High boiling point
d) Low boiling point
Answer: a
Clarification: The strong basic acid type I has high overall basicity. Therefore this gives good effluent quality. Indian FFIP is a type of type I SBA.

5. Which type of character does the strong basic acid type II have?
a) High basicity
b) Low basicity
c) High boiling point
d) Low boiling point
Answer: b
Clarification: The strong basic acid type II has low basicity. Therefore this requires more caustic acid for regeneration. Indian NIP is a type of strong basic acid type II.

6. For which type of pollutant contained in water the macro porous type of weak basic acid is used?
a) Organic contaminant
b) Inorganic contaminant
c) Heavy metals
d) Monochromic ions
Answer: a
Clarification: To remove organic content macro porous weak base anion resin is used. Weak basic acids can be regenerated with stoichiometric regenerated. For treatment of waters which do not provide organic fouling gel type is used.

7. Which of these is not a characteristic for coarse particle sized resins?
a) Poor rate of exchange
b) More attrition loss
c) Low pressure drop
d) Good backwash expansion
Answer: d
Clarification: Coarse particle sized resins have a poor rate of exchange. These have high attrition loss. They don’t have a good backwash expansion.

8. What is the uniform coefficient of resin?
a) Ratio of 40% retained to ratio of 90% retained
b) Ratio of 40% retained to ratio of 70% retained
c) Ratio of 40% retained to ratio of 80% retained
d) Ratio of 30% retained to ratio of 90% retained
Answer: a
Clarification: Ratio of 40% retained to ratio of 90% retained is defined as a uniform coefficient. Effective size is defined as the screen opening that will retain 90% of the screenings. Particle size distribution is determined by sieve analysis.

9. What is the specific gravity of anion resin?
a) 1.05-1.115
b) 4.4-7.3
c) 1.15-1.23
d) 1.23-1.56
Answer: a
Clarification: The specific gravity of anion resin is 1.05-1.115. Cations are denser than anions. The density of cation resins are 1.2-1.3 gm.

10. What is the surface area of the gel resin?
a) 0.01m2/gm
b) 0.5 m2/gm
c) 1-2m2/gm
d) 2-4 m2/gm
Answer: a
Clarification: The surface area of the gel resin is 0.01 m2/gm. The surface area is extremely negligible. Macro porous resins have larger areas.

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250+ TOP MCQs on Storm Water Flow and Answers

Waste Water Engineering Multiple Choice Questions on “Storm Water Flow”.

1. Storm water can even occur as snow melts.
a) True
b) False
Answer: a
Clarification: Storm water, also spelled stormwater, is water that originates during precipitation events and snow/ice melts. Stormwater can soak into the soil (infiltrate), be held on the surface and evaporate or runoff and end up in nearby streams, rivers or other water bodies (surface water).

2. Which of the following is not a negative effect of storm water?
a) Volume
b) Runoff
c) Potential contaminants
d) Evaporation
Answer: d
Clarification: In developed environments, unmanaged storm water can create two major issues: one related to the volume and timing of runoff water (flooding) and the other related to potential contaminants that the water is carrying (water pollution).

3. Pollutants entering surface waters during precipitation events is termed ________
a) Runoff
b) Polluted runoff
c) Contaminated runoff
d) Water flow
Answer: b
Clarification: Pollutants entering surface waters during precipitation events is termed polluted runoff. Daily human activities result in the deposition of pollutants on roads, lawns, roofs, farm fields, etc.

4. Water is recycled into the atmosphere by vegetation through the process called ______
a) Evaporation
b) Evapotranspiration
c) Precipitation
d) Runoff
Answer: b
Clarification: Before development occurred most rainfall soaked into the ground and contributed to groundwater recharge or was recycled into the atmosphere by vegetation through evapotranspiration.

5. Stream erosion can be caused by excess ______
a) Precipitation
b) Evapotranspiration
c) Penetration
d) Transpiration
Answer: a
Clarification: Stream erosion can be caused by excess pollutants from the increased stormwater flow. It can further lead to weed invasion and alter natural flow regimes.

6. Storm water is a major cause of urban flooding.
a) True
b) False
Answer: a
Clarification: Storm water is a major cause of urban flooding. When the storm water overwhelms the capacity of drainage systems, urban flooding is caused.

7. Which of these is a single event?
a) Monsoon rain
b) Flash flood
c) Flood
d) Volcano eruption
Answer: b
Clarification: Flash flood is considered as a single event. It occurs for a short period of time without prior notice and with major after effects.

8. What is the amount spent in the UK every year because of flooding?
a) £250
b) £260
c) £270
d) £280
Answer: c
Clarification: According to the Federal Emergency Management Agency almost 40 percent of small businesses never reopen their doors following a flooding disaster. In the UK, urban flooding is estimated to cost £270 million a year (as of 2007) in England and Wales; 80,000 homes are at risk.

9. When was SWMM developed?
a) 1970
b) 1980
c) 1990
d) 2000
Answer: a
Clarification: SWMM was first developed in 1970 and has undergone four major upgrades since those years. It stands for Storm Water Management System.

10. Which year was the SWMM approved?
a) 2000
b) 2002
c) 2005
d) 2008
Answer: c
Clarification: SWMM 5 was approved FEMA Model Approval Page in May 2005 with this note about the versions that are approved on the FEMA Approval Page SWMM 5 Version 5.0.005 (May 2005) and up for NFIP modeling.

11. In which of the months does the maximum sewage flow occur in India?
a) March
b) May
c) July
d) September
Answer: c
Clarification: In India, the maximum sewage flow occurs in the month of June and July. This is because maximum precipitation occurs in these months. Hence the adequate storm water creates maximum sewage.

12. Which of the following runoff formula is correct w.r.t. Kuitchling formula?
a) I = 2567 / (t+20)
b) I = 2667 / (t+20)
c) I = 2676 / (t+10)
d) I =2867 (t+10)
Answer: b
Clarification: Runoff according to the Kuitchling formula is given by,
I = 2667 / (t+20) (for storm once in 10 years)
I = 3084 / (t+20) (for storm once in 15 years)
Where t is time (minutes) and I is precipitation (mm/hr).