Diagrammatic reference would be highly appreciated... Thanks in advance...

Hi Manthan,

It really depends on the gas/ gasses you want to measure and on the type of surface. Could you provide more information? Are we talking about fluxes from a soil?

Apology for incomplete information... I am willing to analyse Carbon dioxide (which will be generated if the oxygen level is optimum) and methane (which will be generated if the sub surface conditions are anaerobic by methanogenesis) from a landfill site.... !

Moreover the landfill site has been shut down and covered with soil.. so according to the assumption, the conditions might have been anaerobic beneath that layer of soil.. However, I am only concerned with the surface emission and not the horizontal movement of these gases in the subsurface deposits... !

Wow! This is an interesting problem. I also never worked with landfill and I'm not an expert on Methane emissions (although they are also very interesting). But I can tell you the two things I would go for:

if the orography is appropriate (relatively flat surface and at least 200-300 m in diameter), I would use eddy covariance technology. Fast analysers for methane now exist and it will tell you a lot on the fluxes of the two gasses change in time. But it has some costs, you would probably have to spend about 70-90K euros.

another option could be to use the concentration gradient. This approach is used to monitor CO2 efflux continuously. Basically you have to purchase CO2 concentration sensors that you insert at different depths in the soil. In your case: just beneath the soil layer used to cover the landfill; at an intermediate depth; 10 cm below surface and 20 cm above it. To calibrate the efflux estimated from the gradient, you will have to measure the CO2 efflux with an infrared gas anaylser (Licor 8100 for example). This method works perfectly with CO2, but I don't know if sensors are available for methane.

it has the advantage of costing at lot less than eddy covariance (each gradient will cost you around 1500 euros).

Hope I was able to give you some useful information.

Let us know how you solved the problem,

Best,

Simone

First let me have the opportunity to thank both of you.... @ Simone... I will be analysing the samples in the laboratory using Gas Chromatography... So What I actually need to do is, just to collect the sample... now... there where the twist is... I am in a confusion regarding the full proof procedure to collect the sample...

Thank you once again....

I see,

I can't really help then, as I'm not confident with gas chromatography. All I can say is that you should collect the sample trying to disrupt it the least possible. Good luck,

Simone

Dear Manthan you can use the chamber method. You can check my paper on methane surface emission,

@ Pardis.. Yes I will be using static chambers for collecting the gas...

@ Fulvio.... The protocol seems to be containing much valuable information... thanky you for the help...

@ Prof. Fernando... Yours was a really great help..... Thank you very much... !

Manthan, I used static chambers for my thesis work to collect CO2, N2O and CH4, and ran on GC. The construction design is easy to follow using the information Fulvio provided here.