ENV 4053/5055: Chemical Fate and Transport
Homework 1
Due Wed, 9/6/00 
  1. A typical motorcycle emits about 20 g of CO per mile. 


    2. a) What volume of CO would a 5-mile trip produce after the gas cools to 25C (at 1 atm)? (Note that the conversion factor for gases at 25C and 1 atm is 24.465, and not 22.465.) 

    b) Per meter of distance traveled, what volume of air could be polluted so that the air quality standard of 9 ppm is met? 
     

  2. Text Chapter 1, Problem 3 

    3.  
  3. Text Chapter 1, Problem 4 

    4.  
  4. A lagoon with volume 1200 m^3 has been receiving a steady flow of waste at a rate of 100 m^3/day for a long enough time to assume that steady-state conditions apply. The pollutant has a reaction rate coefficient of 0.20/d. The waste entering the lagoon has a concentration of 10 mg/L. Assuming completely mixed conditions, 


    5. a) What is the concentration of the pollutant in the effluent leaving the lagoon? 

    b) If the input waste concentration suddenly increased to 100 mg/L, what would be the effluent concentration 7 days later? 
     

  5. A bar with volume 500 m^3 has 50 smokers in it, each smoking two cigarettes per hour. An individual cigarette emits, among other things, about 1.4 mg of formaldehyde (HCHO). Formaldehyde converts to carbon dioxide with a reaction rate coefficient of 0.40/hr. Fresh air enters the bar at a rate of 1000 m^3/hr, and stale air leaves at the same rate. 


    6. a) Assuming complete mixing, estimate the steady-state concentration of formaldehyde in the air. At 25C and 1 atm of pressure, how does the result compare with the threshold for eye irritation of about 0.05 ppm? 

    b) Suppose the air in the bar is clean when it opens at 5pm. If formaldehyde is emitted from cigarette smoke from 50 smokers who are at the bar starting at 5pm (same mass rate as in part a), what would the concentration be at 6pm? 
     

  6. Text Chapter 1, Problem 6 
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