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Title: Chlorine-36 as a tracer of perchlorate origin

Journal Article · · Environmental Science & Technology
DOI:https://doi.org/10.1021/es9012195· OSTI ID:970906
 [1];  [2];  [2];  [3];  [4];  [5];  [6]
  1. University of Illinois, Chicago
  2. University of Illinois
  3. U.S. Geological Survey, Reston, VA
  4. Shaw Environmental, Inc., Lawrenceville, NJ
  5. Texas Tech University, Lubbock
  6. ORNL

Perchlorate (ClO{sub 4}{sup -}) is ubiquitous in the environment. It is produced naturally by atmospheric photochemical reactions, and also is synthesized in large quantities for military, aerospace, and industrial applications. Nitrate-enriched salt deposits of the Atacama Desert (Chile) contain high concentrations of natural ClO{sub 4}{sup -}, and have been exported worldwide since the mid-1800s for use in agriculture. The widespread introduction of synthetic and agricultural ClO{sub 4}{sup -} into the environment has contaminated numerous municipal water supplies. Stable isotope ratio measurements of Cl and O have been applied for discrimination of different ClO{sub 4}{sup -} sources in the environment. This study explores the potential of {sup 36}Cl measurements for further improving the discrimination of ClO{sub 4}{sup -} sources. Groundwater and desert soil samples from the southwestern United States (U.S.) contain ClO{sub 4}{sup -} having high {sup 36}Cl abundances ({sup 36}Cl/Cl = 3100 x 10{sup -15} to 28,800 x 10{sup -15}), compared with those from the Atacama Desert ({sup 36}Cl/Cl = 0.9 x 10{sup -15} to 590 x 10{sup -15}) and synthetic ClO{sub 4}{sup -} reagents and products ({sup 36}Cl/Cl = 0.0 x 10{sup -15} to 40 x 10{sup -15}). In conjunction with stable Cl and O isotope ratios, {sup 36}Cl data provide a clear distinction among three principal ClO{sub 4}{sup -} source types in the environment of the southwestern U.S.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
Work for Others (WFO)
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
970906
Journal Information:
Environmental Science & Technology, Vol. 43, Issue 18
Country of Publication:
United States
Language:
English