Reference no: EM131310558
The ''soil venting'' shown in the figure below is used to treat soil contaminated with volatile, toxic liquids. In the present situation, the porous soil particles are saturated with liquid TCE, a common industrial solvent. The contaminated soil is dug up at the waste site and loaded into a rectangular trough. The soil consists of coarse, porous mineral particles with an average diameter of 3 mm, loosely compacted into a packed bed with a void fraction 0.5.
Air is introduced at the bottom of the trough through a distributor and flows upward around the soil particles. Liquid TCE satiating the pores of the soil particle evaporate into the air stream. Consequently, the TCE concentration in the air stream increases from the bottom to the top of the trough. Usually, the rate of TCE evaporation is slow enough so that the liquid TCE within the soil particle is a constant source for mass transfer, at least until 80% of the volatile TCE soaked within the soil is removed. Under these conditions, the transfer of TCE from the soil particle to the air stream is limited by convective mass transfer across the gas film surrounding the soil particles.
The mass flow rate of air per unit cross section of the empty bedis 0:1 kg/m3.s. The process is carried out at 293 K. At this temperature, the vapor pressure of TCE is 58 mmHg. The molecular diffusion coefficient of TCE vapor in air is given in example 4 of this chapter.
a. What is the gas-film mass-transfer coefficient for TCE vapor in air?
b. At what position in the bed will the TCE vapor in the air stream reach 90% of its saturated vapor pressure? In your solution, you may want to consider a material balance on TCE in the gas phase within a differential volume element of the bed.
Assume the convective mass-transfer resistances associated with air flowing over the top surface of the bed are negligible and that there is no pressure drop of the gas stream through the bed so that the total system pressure remains constant at 1 atm.
Companies protect their digital assets overseas
: Prepare a 3 to 5 paragraph briefing statement that can be used to answer the above question. Your audience will be attendees at a conference for small business owners who are interested in expanding their footprint overseas (sales, offices, produ..
|
Generated matrix forms a magic squares
: Write a C++ program that fills random squares of 3 by 3, with unique numbers from 1 to 9, and tests if the generated matrix forms a Magic Squares.
|
What is the liquid phase mass transfer coefficient
: Estimate the depth of packing if the desired concentration of dissolved CO2 in the outlet liquid is 95% of the saturation value for dissolved CO2 in water under CO2 partial pressure of 2 atm and 20°C.
|
Discuss about the watergate scandal
: Discuss about The Watergate Scandal.In this exercise you are to write a short paper analyzing the Watergate scandal of the early 1970's. Who was involved and what rank or level did the hold. According to our book, name the type of crime this fall..
|
What is gas film mass transfer coefficient for tce vapor
: What is the gas-film mass-transfer coefficient for TCE vapor in air?- At what position in the bed will the TCE vapor in the air stream reach 90% of its saturated vapor pressure?
|
One destination address byte
: Consider a slotted ring of length 20km with a data rate of 100Mbps and 1000 repeaters, each of which introduces a 1-bit delay. Each slot contains room for one source address byte, one destination address byte, two data bytes and 8 control bits for..
|
Estimate the test section velocity in miles
: An open-circuit wind tunnel draws in sea-level standard air and accelerates it through a contraction into a 1 m-by-1 m test section.
|
Evaluate the final dissolved oxygen level
: If 283 K wastewater, initially containing a dissolved oxygen level of 5×10-3 mmol/L and filling the basin to a depth of 4.55 m, is aerated for 9000 s, evaluate the final dissolved oxygen level.
|
Create a server diagram to model the physical view of system
: To present a static model of the system, create a diagram for a layered architecture view of the system.Using the components you identified in your layered view of the system, create an activity diagram that shows how a customer would place an ord..
|