| 摘要 |
<p>A method for the evaluation of the pollution characteristics of natural soils by hydrocarbon compounds from samples, in which the sample is heated firstly in a non-oxidising atmosphere and then in an oxidising atmosphere, in the following stages :-a)The sample is heated rapidly to 80 - 120 degrees C. for a determined time ; b) From this temperature, the sample is heated to less than 200 degrees C. on a gradient of 2 - 30 degrees C./mn and this temperature maintained for a determined time; c) The temperature is then raised to a third value, less than 500 degrees C., on a gradient of 10 - 40 degrees C./mn d) The temperature is raised to a fourth value, a maximum of 850 degrees C.; e) From these four stages , four parameters Q0, Q1, Q2 and Q3 are determined, representative of the nature and amount of the hydrocarbons in the sample ; f) After heating to the fourth value, the residues are burned in an oxidizing atmosphere between a temperature greater than 350 degrees C to a maximum of 850 degrees C., at 20 - 50 degrees C/mn ; g) A parameter Q4 i s determined, representative of the amount of residual organic carbon after the pyrolysis ; h) From the five parameters Q0, Q1, Q2, Q3 and Q4,a pollution characteristic of the sample could be derived.</p> |
