S. Grant,

Some of my colleagues have used sprinkler irrigation to remove volatiles from
contaminated ground water (Roy Spalding et al., Univ. of Nebraska, Lincoln, NE).

We have not done isotopes, delta C-13 or delta Cl-37 on chlorinated organic
volatiles in ground or soil gases or groundwater. I believe that one group of
groundwater scientists, perhaps in Canada, did some of this work, but I have
not seen or read any of this literature.

Glen Martin
Water Sciences Laboratory
School of Natural Resource Sciences
University of Nebraska, Lincoln, NE, USA
voice: 402-472-8210;  FAX: 402-472-9599

At 01:02 PM 6/12/98 -0400, you wrote:
>I have recently received the following e-mail. Can anybody help?
>Please reply directly to Steve Grant: [log in to unmask]
>
>Thanks!
>Andrea
>
>>Mime-Version: 1.0 (NeXT Mail 3.3 v118.2)
>>From: Steve Grant <[log in to unmask]>
>>Date: Tue,  2 Jun 98 18:30:18 +0200
>>To: [log in to unmask]
>>Subject: question
>>Cc: [log in to unmask] (Ira P May)
>>Reply-To: [log in to unmask]
>>
>>
>>The chlorinated solvent trichloroethylene (C2HCl3; TCE) is a
>>suspected human carcinogen and a ground-water contaminant at many
>>current and formerly used Army facilities. (Chem Abs Reg No:
>>79-07-6; MW 0.13139 kg/mol; m.p.-84.7 C; b.p 87.2 C; Henry's Law
>>constant, 0.0071 bar m^3/mol; vapor pressure at 25 C, 9.8 kPa;
>>aqueous solubility at 25 C 8.4 mmol/kg) TCE in the subsurface is
>>thought to be partitioned between the gas phase, the aqueous
>>solution phase,  isolated globules of separate organic liquid phase
>>and the soil organic-matter solid phase.
>>
>>Remediation by vapor extraction from the vadoze zone above the
>>water table is commonly employed to remove TCE from contaminated
>>ground. At many sites the concentrations of TCE in the extracted
>>vapors are higher than would be predicted by the concentrations of
>>TCE in the soil solutions. The causes for these elevated TCE
>>concentrations are unknown and of considerable interest to those
>>responsible for environmental clean up. The condensed-phase source
>>of the TCE in extracted vapor cannot be inferred from current
>>measurements.
>>
>>Presumbably the isotopic abundances differ in gaseous TCE depending
>>upon the condensed phase with which the gas is at equilibrium, that
>>is whether the vapor is at equilibrium with aqueous solutions,
>>pure-TCE liquids, or soil organic-matter sorbates.
>>
>>Could the condensed phase providing TCE to the vapor-extractant
>>gases be inferred by the isotopic fractionation of the
>>vapor-extracted TCE?
>>
>>Steve Grant                     office: 603-646-4446
>>CRREL                              fax: 603-646-4561
>>72 Lyme RD                      E-mail: [log in to unmask]
>>Hanover NH 03755-1290 USA
>>
>>(Note: Do NOT reply to [log in to unmask], which is
>>inside the CRREL ``firewall.'' Please reply to the E-mail address in
>>the footer.)
>>
>
>
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