title: Effect of soil moisture on chlorine deposition.
abstract: The effect of soil moisture on chlorine (Cl(2)) deposition was examined in laboratory chamber experiments at high Cl(2) exposures by measuring the concentration of chloride (Cl(-)) in soil columns. Soil mixtures with varying amounts of clay, sand, and organic matter and with moisture contents up to 20% (w/w) were exposed to ≈3×10(4)ppm Cl(2) vapor. For low water content soils, additional water increased the reaction rate as evidenced by higher Cl(-) concentration at higher soil moisture content. Results also showed that the presence of water restricted transport of Cl(2) into the soil columns and caused lower overall deposition of Cl(2) in the top 0.48-cm layer of soil when water filled ≈60% or more of the void space in the column. Numerical solutions to partial differential equations of Fick's law of diffusion and a simple rate law for Cl(2) reaction corroborated conclusions derived from the data. For the soil mixtures and conditions of these experiments, moisture content that filled 30-50% of the available void space yielded the maximum amount of Cl(2) deposition in the top 0.48cm of soil.
authors.affiliation: Air Force Research Laboratory, Airbase Technologies Division, 139 Barnes Dr. Suite 2, Tyndall AFB, FL 32403, United States. Electronic address: jhearn@leeuniversity.edu.
authors.forename: John
authors.initials: J
authors.lastname: Hearn
authors.affiliation: Universal Technology Corporation, 139 Barnes Dr. Suite 2, Tyndall AFB, FL 32403, United States.
authors.forename: Jeffery
authors.initials: J
authors.lastname: Eichler
authors.affiliation: Air Force Research Laboratory, Airbase Technologies Division, 139 Barnes Dr. Suite 2, Tyndall AFB, FL 32403, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hare
authors.affiliation: Air Force Civil Engineer Center, 139 Barnes Dr. Suite 2, Tyndall AFB, FL 32403, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Henley
mesh_terms: D000538:Aluminum Silicates; D002713:Chlorine / Q000737:chemistry*; D000077215:Clay; D006813:Humidity; D015233:Models, Statistical; D012822:Silicon Dioxide; D012987:Soil / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000538:Aluminum Silicates; D012987:Soil; D002713:Chlorine; D012822:Silicon Dioxide; D000077215:Clay
keywords: Chlorine deposition; Soil moisture; Toxic industrial chemical