How much contaminant escapes through a barrier in 30 days?

  • Thread starter Thread starter Sadeq
  • Start date Start date
AI Thread Summary
A structural engineer seeks assistance with a contamination calculation involving a soil barrier with specific properties, including porosity, bulk density, and permeability. The scenario involves a hydraulic head and an initial contaminant concentration, requiring the calculation of contaminant escape over 30 days. Key hints include calculating the mass of solids to water volume ratio and considering discrete transits of bed volumes for the flow through the barrier. The engineer expresses a lack of confidence in this area, highlighting the need for guidance. The discussion emphasizes the importance of understanding groundwater principles, as outlined in a specific textbook.
Sadeq
Messages
103
Reaction score
0
hi all
i am structural engineer, and i tok an environment course because the course options was limted
i have a question to solve but the problem i feel stupied because my back ground in this area is zero
so please help me
the question is

A soil has a porosity of 0.23, a bulk density of 1.87 Mg/m3 and a permeability of 9.6 x10-8
m/s. It is being used as a clean-up barrier 450mm thick underneath a waste deposit that covers 50 x 120 m plan area. There is a hydraulic head of 1.8m across the barrier. If the contaminant concentration in the fluid which passes through the barrier is, initially, 125 mg/l, calculate how much contaminant escapes through the barrier in 30days. The partition coefficient is 25 l/kg. Ignore diffusion and dispersion effects in this case and assume that the thickness of the barrier acts uniformly.
Hints:
1) you will (probably1) need to calculate the ratio of the mass of solids to the volume of water in the soil.
2) you may consider the flow through the barrier as being a number of discrete transits, each comprising one bed-volume which suddenly replaces the previous bed-volume, waits without moving for the length of time indicated by the transit time, and then is suddenly displaced by the next bed volume.
3) I suggest you work out the contaminant that escapes for the first bed-volume; then work out the volume escaping in the second bed-volume. After that you will be able to set up a spreadsheet-based solution for as many bed-volumes as you need.



please help me ,because i feel lost
 
Physics news on Phys.org
It's not within my comfort zone but it seems to be covered well in a textbook,
"Earth Science: The Water Planet" issued by McGraw Hill, chapter 3 Groundwater.

(Google hints)
 
Thank you very much.
I don't have an access for this book.
The main problem this not my major ,so please guide me

I will be thankful fro you for whole of my life
 
Thread 'Confusion regarding a chemical kinetics problem'

Thread 'Confusion regarding a chemical kinetics problem'

TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
View full post »

Thread 'Prove that evolution is constant (Provide at least two arguments to support your position)'

I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
View full post »

Hot Threads

Recent Insights

Back
Top