7 Well mixed with constant flow in and out reactor CSTR is t

7. Well mixed with constant flow in and out reactor (CSTR) is the most frequently used in environmental engineering problems with a steady state assumption. a False b. True 8. Pollutants transport in a porous media is facilitated by following mechanism a. advection b. diffusion c. dispersion d. all of these 9. Dispersion is due to the turbulent diffusion: a. True b. False 1 0 TMDL is. . . a. Total Mcasured Daily Load b. Total Maximum Dairy Load c. Total Monitored Dolphins Life d. Total Maximum Daily Load 11. Organic contaminants in water can include: b. Trihalomethanes (THM) a. Chlorinated hydrocarbons (HC) and Volatile Organic Chemicals (VOC) c. Haloacetic Acids (HAAs) d. All of these 12. NHs is toxic to many aquatic organisms. a. False b. True 13. DO deficit, D is the addition of saturation concentration of the oxygen and current concentration of DO in the water at a given water temperature. a. False b. True 14. Most common BOD expression is BODs which describes the amount of oxygen consumed a, 5 hours b. 5 minutes c. 5 weeks d. 5 days

Solution

7. Answer is b.True, We assume the steady state condition of CSTR for solving environmental enginnering problems. By this assumption the time derivatives are equal to zero.

8. Answer is d.all of these. all the options advection, diffusion and dispersion all of the three mechanism will facilitates the pollutant to pass through porous media. thi process is called multiphase porous medium system.

9. Answer is a.True. dispersion is caused by turbulent diffusion.

10.Answer is d.Total maximum daily load.

11. Answer is d.all of these. all the options are come under organic contaminents in water and those are harmful for health

12. Answer is b.true. Presence of NH3 (ammonia ) in water is dangerous for aquatic organisms.

13. Answer is a.False. Do deficit is the subtraction of current concentration of DO from the saturated DO content.

14. Answer is d.5days. BOD5 means the amount of oxygen consumed in 5 days. In the span of 5 days around 60 to 70% of oxygen gets consumed.