Waste Water Treatment MCQ Questions and Answers in Civil Engineering

Question: Grit chamber is similar to which of the following?
a) Screening unit
b) Sedimentation tank
c) Coagulation tank
d) Sand bed

Answer: b

Question: Which of these is not a grit removal equipment installed in the aerated grit chamber?
a) Screw conveyers
b) Tubular conveyers
c) Jet pumps
d) Communitors

Answer: d

Question: Usually while designing what is the range of length of the aerated grit chamber assumed?
a) 7.5-20
b) 4-6 m
c) 25 m
d) 50 m

Answer: a

Question: ________ combines aeration basin and secondary clarifier into single unit.
a) Primary clarifier
b) Aerobic unit
c) Sequential batch reactor
d) Secondary clarifier

Answer: c

Question: Which of the following ion get released from the cation exchange column?
a) H+
b) Na+
c) K+
d) Ca+2

Answer: a

Question: In ion-exchange process, the capital cost is _________ and the operational expenses are ______________
a) Low, high
b) High, low
c) High, high
d) Low, low

Answer: c

Question: Which of the following is not a disadvantage of Ozonation?
a) Chemicals
b) Costs
c) Energy
d) Fire hazard

Answer: a

Question: What is the colour of ozone?
a) Violet
b) White
c) Grey
d) Colourless

Answer: d

Question: How is the electrical requirement for the ozonation process expressed mathematically?
a) EE/O =EEt/ Vlog(Ci-Cf)
b) EE/O =EEt/ (Ci-Cf)
c) EE/O =EEt Vlog(Ci-Cf)
d) EE/O =EEt(Ci-Cf)

Answer: a

Question: Determination of flow increase is used for the monitoring of ___________
a) sea pollution
b) River pollution
c) Lake pollution
d) Tank pollution

Answer: b

Question: On which of the following does the self purification process does not depend?
a) Volume
b) Flow rate
c) Temperature
d) Aquatic species

Answer: d

Question: In which of the following treatment involve oxidation of organic constituents of the wastewater?
a) Primary treatment
b) Secondary treatment
c) Advanced treatment
d) Final treatment

Answer: b

Question: Biological process is used to remove _______
a) Settleable solids
b) Volatile solids
c) Dissolved solids
d) Colloids

Answer: c

Question: Which of these is not an advantage of a trickling filter?
a) Temperature
b) Construction cost
c) Oxygen delivery
d) Electric systems

Answer: a

Question: The effective size of sand of the slow sand filter is __________
a) 0.1-0.2mm
b) 0.2-0.3mm
c) 0.4-0.7mm
d) 1-2mm

Answer: b

Question: In which process of water softening, ion exchange phenomenon takes place?
a) Lime soda process
b) Zeolite process
c) Boiling
d) Demineralization process

Answer: b

Question: Permutit has an exchange value of ________ grams of hardness per m3 of zeolite.
a) 10,000
b) 20,000-30,000
c) 35,000-40,000
d) 40,000-50,000

Answer: c

Question: If the precipitate formed is soft, loose and slimy, these are __________ and if the precipitate is hard and adhering on the inner wall, it is called _____________
a) Sludges, scale
b) Scale, sludges
c) Sludges, rodent
d) Scale, rodent

Answer: a

Question: Fishes can store more quantity of ___________ in their bodies.
a) Mercury
b) Bismuth
c) Palladium
d) Chlorine

Answer: a

Question: Helminth in the water causes __________
a) Hook worm
b) Amoebic dysentery
c) Cholera
d) Typhoid

Answer: a

Question: The decomposition of the matter produces into ___________ and in presence of ____________
a) Carbondioxide and oxygen
b) Oxygen and nitrogen
c) Nitrogen and carbondioxide
d) Nitrogen and chlorine

Answer: a

Question: The type of solids which floats in sewage is __________
a) Suspended solids
b) Settleable solids
c) Dissolved solids
d) Total solids

Answer: a

Question: The decomposition of sewage takes place, causing a pungent smell. Which of the following causes the pungent smell?
a) CO2
b) H2SO4
c) HCL
d) H2S

Answer: d

Question: The Federal Water Pollution Control Act of 1948 was the first major U.S. law to address water pollution.
a) 1945
b) 1946
c) 1947
d) 1948

Answer: d

Question: Who is responsible for the clean-up of oil spill?
a) HWS
b) APS
c) Oil Pollution Act
d) SARA

Answer: c

Question: Which of the following is the physical monitoring of the lake?
a) PH
b) COD
c) BOD
d) Turbidity

Answer: d

Question: The central pollution control board and the department of ocean and environment has established __________ stations over the entire coastal line of the country.
a) 171
b) 172
c) 173
d) 174

Answer: d

Question: The term ‘Sullage’ refers to:
a) Fresh wastewater
b) Septic wastewater
c) Wastewater from kitchen, laundry
d) Toxic wastewater

Answer: c

Question: Which minerals and in what form are present in ground water?
a) Fe & Mn in Ferrous and Manganous
b) Fe & Cu in Ferric and Cupric
c) Fe & Mn in Ferric and manganous
d) Cu & Mn in Cuprous and manganous

Answer: a

Question: Which of the following requires aesthetically pleasant water?
a) Domestic use
b) Industrial use
c) Irrigation
d) Aquaculture

Answer: b

Question: The fluoride concentration for prevention of dental caries is ____________
a) 1mg/l
b) 2mg/l
c) 3mg/l
d) 4mg/l

Answer: a

Question: The process of reducing the fluoride content from water is called _____
a) Chlorination
b) Fluoridation
c) Defluoridation
d) Flocculation

Answer: c

Question: Fluorex is a special mixture of ____________
a) Di-calcium phosphate and carbon
b) Tri-calcium phosphate and hydroxyapatite
c) Di-calcium phosphate and phosphoric acid
d) Tri-calcium phosphate and carbon

Answer: b

Question: Which of these metals does not require alloying for oxidation resistance?
a) Iron
b) Copper
c) Aluminum
d) Molybdenum

Answer: c

Question: How can caustic embrittlement be avoided?
a) Addition of nickel
b) Increasing potential
c) Decreasing carbon
d) Adding tannins

Answer: d

Question: From which of the following methods can toxic chemicals be removed?
a) Sorption
b) Adsorption
c) Absorption
d) Dewatering

Answer: a

Question: What is the percentage of aerobically digested sludge?
a) 0.2-0.5
b) 0.3-0.6
c) 1.0-2.0
d) 1.5-3.0

Answer: c

Question: What is the % of dry solids assumed for a primary sludge from a settling tank at the outlet?
a) 12%
b) 5-7%
c) 8%
d) 9-11%

Answer: b

Question: What is the specific gravity of settleable particles in the grit chamber?
a) 2.98
b) 2.56
c) 2.65
d) 2.89

Answer: c

Question: What is the amount of grit quantities captured by the aerated grit chamber?
a) 0.004-0.20 m3/103.m3
b) 0.25 m3/103.m3
c) <0.004 m3/103.m3
d) 0.5 m3/103.m3

Answer: a

Question: What does SBR stand for?
a) Secondary batch reactor
b) Sequential biological reactor
c) Secondary biological reactor
d) Sequential batch reactor

Answer: d

Question: Ion-free water coming out from the exchanger is known as ____________
a) Potable water
b) Disinfected water
c) Coagulated water
d) Demineralised water

Answer: d

Question: How many oxygen atoms are present in the ozone?
a) 1
b) 2
c) 3
d) 4

Answer: c

Question: Which of the following is not correct regarding Ozonation?
a) Does not requires chemicals
b) Eliminates bad taste
c) Eliminates odour
d) Operational costs are low

Answer: d

Question: At what pH ozonation is carried out?
a) 8
b) 9
c) 11
d) 7

Answer: a

Question: which of the following does not include in the monitoring of river pollution?
a) Assessing the immediate water quality
b) Development activities in the region
c) Determination of flow increase
d) Colour of the water

Answer: d

Question: In a flowing stream, the breakdown of degradable wastes by bacteria ________ dissolved oxygen.
a) Increases
b) Depletes
c) Maintains
d) Improves

Answer: b

Question: Trickling filter is used in which of the following wastewater treatment processes?
a) Primary treatment
b) Secondary treatment
c) Advanced treatment
d) Final treatment

Answer: b

Question: What is the percentage removal of BOD by stabilization ponds?
a) 20%
b) 45%
c) 65%
d) 95%

Answer: c

Question: In which process of water softening, the chemicals are added to remove hardness from water?
a) Lime soda process
b) Zeolite process
c) Boiling
d) Demineralization process

Answer: a

Question: The thickness of the layers of filter sand of zeolite softener is ____________
a) 20cm
b) 30cm
c) 40cm
d) 100cm

Answer: d

Question: __________ poisoning water in Japan is from fishes.
a) Bismuth
b) Arsenic
c) Antimony
d) Palladium

Answer: b

Question: The ____________ is an important requirement of the aquatic life.
a) Dissolved nitrogen
b) Dissolved chlorine
c) Dissolved oxygen
d) Dissolved methane

Answer: c

Question: The presence of which of the following in sewage indicates nitrogen content before decomposition of sewage?
a) Nitrites
b) Nitrates
c) Free ammonia
d) Albuminoid nitrogen

Answer: d

Question: Imhoff cone is used to measure the _______
a) Suspended solids
b) Settleable solids
c) Dissolved solids
d) Total solids

Answer: b

Question: Section __________ of CWA regulates discharges of hazardous substances.
a) 311(b)(2)(B)
b) 311(b)(2)(A)
c) 312(b)(2)(A)
d) 311(b)(1)(A)

Answer: b

Question: Which CWA program controls water pollution by regulating point sources?
a) SPCC
b) PCC
c) NPDES
d) PDA

Answer: c

Question: A large amount of soil can move with the run off called ___________
a) Soil erosion
b) Soil conservation
c) Soil pollution
d) Soil moving

Answer: a

Question: Which one of the below is not an attribute of drinking water?
a) Aesthetics
b) Economic
c) Safety
d) Source

Answer: d

Question: On how many conditions does the intervention of wastewater depend on?
a) 5
b) 7
c) 6
d) 4

Answer: b

Question: What percentage of solids does wastewater contain?
a) 0.5%
b) 5%
c) 0.1%
d) 1%

Answer: c

Question: Which of the following is the pure compound?
a) Sodium fluoride
b) Sodium silico fluoride
c) Hydrofluosilicic acid
d) Sodium fluro carbonate

Answer: a

Question: One cubic metre of bone can treat how much quantity of water containing 3.5 ppm of fluoride?
a) 10m3
b) 100m3
c) 1000m3
d) 10000m3

Answer: b

Question: % chromium mixed with ______ can be used up to 1100^oc
a) Nickel
b) Chromium
c) Aluminum
d) Silicon

Answer: a

Question: Dezincification of brass is prevented by addition of ________
a) Nickel
b) Zinc
c) Arsenic
d) Tungsten

Answer: c

Question: What is the cleaning period for manual grit chambers?
a) 3 days
b) 5 days
c) 48 hours
d) 1 week

Answer: d

Question: What is the term used for reuse of sewage sludge?
a) Compost
b) Solids
c) Biosolids
d) Sludge

Answer: c

Question: Ws = Wsp + Wss What does Wsp stand for in the above equation?
a) Total dry solids
b) Raw primary solids
c) Suspended solids
d) none

Answer: b

Question: Stoke’s law holds good for Reynolds’s number ______
a) Less than 1
b) Equal to 1
c) Greater than 1
d) Nearer to 1

Answer: a

Question: What is required to keep the activated sludge suspended?
a) Carbon-dioxide
b) Nitrogen
c) Oxygen
d) Ammonia

Answer: c

Question: What is the average ozone concentration created during Ozonation?
a) 1000 mg/l
b) 5000 mg/l
c) 10000 mg/l
d) 15000 mg/l

Answer: c

Question: Which of the following methods are used in rural communities?
a) Aerobic digestion
b) Mechanical dewatering
c) Dewatering
d) Composting

Answer: d

Question: Which of the following is a strict anaerobe?
a) Enterobacter
b) Alcaligenes
c) Pseudomonas
d) Methanosarcina

Answer: d