Question

Question 4 A contaminated groundwater contains 60 ug/L (i.e., 0.060 mg/L) of ethylbenzene. You are pumping this groundwater out from your client's site, and have to treat it before it is discharged. You have decided to treat it by air stripping, which will volatilize the ethylbenzene and remove it from the water. Assuming this removal occurs as a single-step process, estimate the volume of air (in L) that needs to be contacted with every 1 L of water to lower the ethylbenzene concentration to 3 g/L. The Henry's Law constant for ethylbenzene is 0.0088 atm.m/mol. Assume 20 °C.

Answer 1

8. Amount of ethylbenzene to be removed per 1 Loo water = (60-3) ug x 12 = 57 kg moreda 57 mg to be removed a moles of ethy I benzene ml 106x10 ug/mol =0.54x156 mol of ethyl benzene is water is very small since, amount of ethy I benrene is water is we can assumie density of Water souitiona density of H.O. Mass of watero 1000 mLx 19 = 1000g moles of water = 1000/18 moles of ethyl benzene remaining in water = 3ug, mole mint = 0.03x10-6 mol 1000/18 = 0.54 x 109 mole fraction of ethyl benzene = 0.033184 C nazene - 0.03>

Applying Henry's law partial pressure - PA EXARH , XA mole fract I XA mole fraction of gas in soin 1 KHS henry's louo.' PER= 0054x1090.0088 atm-m3/mol = 4.8* love atm-m3/mol = 408x10° atm4mol pain - - nd App 0 Pair PEB -4.8x10-12 atmam3 408x106 nair NEB . mol. . atmynd Pv=nRT v=nXRXT. 1 p El X000821 x 293 L 408x10-6 = 5,0x106 L. .