Name _____________________________ Sample Exam CE 326 Principles of Environmental Engineering - First Exam - Closed Book Defendable True/False. If the statement is true as stated, mark it OK. If it is false, correct it by changing the underlined word or words in the sentence so that it will be true. 3 points each. 1. The seven major air pollutants of concern include carbon monoxide, lead, nitrogen oxides, sulfur dioxide, volatile hydrocarbons, ozone, and TCA. 2. The greenhouse effect is a result an accumulation of naturally occurring and anthropogenic gases namely, CO2, methane, nitrous oxide, and CFCs. 3. Ozone depletion in the upper atmosphere (20 - 40 km) is the mainly the result of nitrous oxide release to the atmosphere. 4. Carbon tetrachloride (CCl4) and carbon monoxide are the primary contributors to acid rain. 5. Hydrocarbons, VOCs, and NOx from automotive emissions contribute to photochemical smog which is the primary reason that polluted cities are called non-attainment areas for ozone. 6. The tendency of the atmosphere to resist or enhance vertical motion is termed the Coriolis effect. 7. The lapse rate is defined as the rate of temperature increase (or decrease) experienced by a parcel of air that expands or contracts adiabatically as it is raised through the atmosphere. 8. On average, Americans throw away about 20 pounds of municipal solid waste per person per day. 9. A landfill must be 3,000 m from the nearest airport due to the odors that are associated with the landfilling of municipal solid waste. 10. In a cancer risk assessment the greater the slope factor the greater the risk of cancer. 11. RCRA Subtitle D is the environmental regulation dealing with abandoned hazardous waste sites and the development of the national priorities list (NPL). 12. Henry’s law is important in the design of cyclones for air pollution control. 1 5. Short Answer Problems - 8 points each: 11. Put the letter(s) associated with the following air pollution control equipment next to the indicated item: (A) absorption tower, (B) baghouse, ©) cyclone, (D) adsorption system, (E) electrostatic precipitator, (F) venturi scrubber, (I) incinerator _____ uses corona wire to induce electrical charge ______ uses natural gas and is effective against VOC’s _____ throat section accelerates gas velocity ______ can be wet or dry, wet cleaned by water spray _____ uses trays or inert media to provide surface area ______ efficiency increases as diameter decreases _____ same principle as home vacuum cleaner ______ activated carbon or activated alumina media _____ requires a dry gas stream ______ is often followed by a cyclone _____ must be taken off-line prior to breakthrough ______ historically associated with fire hazard 12. How do modern sanitary landfills minimize many of the environmental problems associated with open dumping (air, water, and land). How is a hazardous waste landfill different from a sanitary landfill? 2 13. Define and explain the significance of the following terms: PCB ____________________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ characteristic waste ________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ ozone hole _______________________________________________________________________ ________________________________________________________________________________ ________________________________________________________________________________ Numerical Problems (20 pts each): 14. What would be the SO2 concentration (in both ppm and g/m3) in the stack gas from a coal burning incinerator (without air pollution control equipment) if the coal contained 3% sulfur? Assume that coal is 97% carbon and 3% sulfur and that all of the sulfur and carbon exit in the stack gas (i.e., there is no ash). Assume that the excess air requirement is 10% and air contains 21% oxygen. Additional information: MW(S) = 32 g/mole; MW©) = 12 g/mole, MW(O2) = 32 g/mole, MW(SO2) = 64 g/mole at STP volume of an ideal gas is 22.4 L/mole; PV=nRT where R= 8.3143 Pa@m3/K@ mole STP =273K and 1 atm (101,325 Pa) 1 m3 = 1000 L C + O2 Y CO2 S + O2 Y SO2 3 15. Assuming that the incinerator (without air pollution control equipment) mentioned in problem (14.) burns 450,000 kg coal per day, what would be the downwind concentration of SO2 in g/m3 for a recipient 3 km downwind and 50 m from the plume centerline? Effective stack height = 80 m, Wind speed = 5 m/s Emission rate of pollutant, E, in g/s Stability Class C, using Martin's equation: sy = 104.0X0.894 and sz = 61.0X0.911 where the dispersion coefficient is in meters and the X distance is in km recipient 50 m Prevailing wind 3 km stack Site boundary 4