Air Pollution and Control Week 10 Answers

                     

Q1. Find the collecting plate area in a horizontal flow, single-stage electrostatic precipitator (ESP) handling an average gas flow of 3.1 m3/s  from a pulverized coal-fired boiler. The required collection efficiency of ESP is 98%. Take drift velocity, ω = 15 cm/sec.

a. 0.189 m2 
b. 64.92 m2 
c. 80.85 m2 
d. 94.54 m2

Answer:- c. 80.85 m2 

Q2. A baghouse filter is having 30 compartments, 220 bags per compartment, and each bag of diameter 12 m and bag length 25 m, with a gas flow rate of 1,500,000 m3/min. Calculate the gross air to cloth ratios. 

  • 0.00241 m/min 
  • 0.0241 m/min 
  • 0.241 m/min 
  • 2.411 m/min

Answer: c

Q3. Calculate the amount of calcium hydroxide (lime) needed to neutralize the HCl (Hydrochloric acid) absorbed from a gas stream having 30 ppm HCl and a flow rate of 15,000 SCFM (Standard Cubic Feet per Minute). Assume an HCl removal efficiency of 98%.

  • 0.04 lb/hr 
  • 1.01 lb/hr 
  • 2.54 lb/hr 
  • 9.6 lb/hr

Answer: c

Q4. What is the maximum toluene removal efficiency possible in a refrigeration-type condenser operating at -125°F if the inlet concentration is 21,000 ppm? Given the outlet partial pressure @ -125°F for toluene is 0.018 mm Hg.

  • 88.58 % 
  • 90.66 % 
  • 98.87 % 
  • 99.88 %

Answer: d

Q5. According to the recently published WHO air quality guidelines, 2021, the permissible limit of SO2 (in µg/m3)  is given as:

  • 20 
  • 40 
  • 60 
  • 80

Answer: b

Q6. Which of the following pollutants is not included in the revised National Ambient Air Quality Standard (NAAQS, 2009):

Answer:- d

Q7. Which of the following Acts is considered as the first act/regulation enacted to address the issue of air pollution:

Answer: b

Q8. According to the notification for e –vehicles for NCR in 2022, the Transport Department, Government of NCT of Delhi is directed to ensure that all the aggregators and delivery service providers should adopt electric vehicles (two-wheelers) in the proportion of ______ within 31st March 2023. 

Answer: d

Q9. Ministry of Road Transport and Highways (MoRTH) decided to move directly from ____________emission standards by 2020

Answer: d

Q10. National Clean Air Programme (NCAP) launched in 2019 targets to reduce 20 % – 30 % of PM2.5 and PM10  concentration by 2024, keeping ______ as the base year for the comparison of concentration.

Answer: d