Application of Geochemical Evaluation to Identify Metals Contamination in Soil at Firing Ranges
Jonathan Myers, Ph.D., Shaw Environmental, Inc., Albuquerque, NM  
Karen Thorbjornsen, Shaw Environmental, Inc., Knoxville, TN   

Tungsten Effects on Soil Environments
Nikolay Strigul, Stevens Institute of Technology, Hoboken, NJ
Washington Braida, Stevens Institute of Technology, Hoboken, NJ
Dimitris Dermatas, Stevens Institute of Technology, Hoboken, NJ
Christos Christodoulatos, Stevens Institute of Technology, Hoboken, NJ
Michael Los, TACOM-ARDEC, US Army Heavy Metals Office, Picatinny Arsenal, Picatinny, NJ

Corrosion Behavior of Tungsten Alloys in the Environment
Abebayo Ogundipe, Stevens Institute of Technology, Hoboken, NJ
Washington Braida, Stevens Institute of Technology, Hoboken, NJ
Dimitris Dermatas, Stevens Institute of Technology, Hoboken, NJ
Christos Christodoulatos, Stevens Institute of Technology, Hoboken, NJ
Michael Los, TACOM-ARDEC, US Army Heavy Metals Office, Picatinny Arsenal, Picatinny, NJ

Evaluation of Phosphate Treatment Methods to Reduce Lead Mobility at Military Small Arms Training Ranges
Dr. R. Mark Bricka, Mississippi State University, Mississippi State, MS 
Mr. Jason Darnell, Mississippi State University, Mississippi State, MS       
Mr. Gene Fabian, US Army Aberdeen Test Center, APG, MD

Recovery and Recycling of Tungsten and Lead from Small Arms Firing Range Soils
Michael F. Warminsky, PE, AMEC Earth and Environmental, Inc., Somerset, NJ
Dr. Steven Larson, U.S. Army Engineer Research and Development Center, Vicksburg, MS

Vertical Distribution and Speciation of Lead at a Recreational Firing Range in Eastern Massachusetts
Jack Duggan, Wentworth Institute of Technology, Boston, MA
Ankit Dhawan, Massachusetts College of Pharmacy and Health Sciences, Boston, MA  

Application of Geochemical Evaluation to Identify Metals Contamination in Soil at Firing Ranges

Jonathan Myers, Ph.D., Shaw Environmental, Inc., 5301 Central Avenue NE, Albuquerque, NM  87108, Tel: 505-262-8726, Fax: 505-262-8855, Email:  jonathan.myers@shawgrp.com
Karen Thorbjornsen, Shaw Environmental, Inc., 312 Directors Drive, Knoxville, TN  37923, Tel: 865-670-2663, Fax: 865-690-3626, Email:  karen.thorbjornsen@shawgrp.com

Lead, antimony, copper, and zinc are expected contaminants in soil at firing ranges due to their presence in bullets and shell casings.  These metals are also naturally occurring in soil, so it is important to distinguish between naturally high background concentrations and actual contamination during site investigations.  Standard statistical tests are prone to high false positive error rates, however, and cannot provide mechanistic explanations for the elevated metal concentrations.  A geochemical evaluation technique has been successfully applied during firing-range investigations to properly identify the contaminated soil samples.  These evaluations are based on the well-established associations of trace elements with specific minerals in the soil matrix.  Correlation plots of trace element concentrations versus major element concentrations are constructed to explore these specific associations.  For example, lead has a natural affinity to adsorb on the surfaces of manganese oxide minerals, and a positive correlation between lead and manganese concentrations is observed for uncontaminated samples.  Anomalous samples that may contain a component of contamination are readily distinguished from uncontaminated samples by their elevated lead/manganese ratios.  Plots of antimony, copper, or zinc versus lead provide supporting evidence for the contaminant source; in oxic soils, covariance of these metal concentrations is not expected unless contamination is present.  These evaluations utilize existing analytical data obtained during typical site investigations, and require only minimal level of effort to perform.  Examples are provided from several firing-range investigations at military installations across the United States, and illustrate the technique’s utility in a variety of geological regimes, soil types, and project sites.  These evaluations have been successfully used to delineate the extent of contamination, identify hot spots for removal actions, confirm the success of remediation efforts, and facilitate site closure decisions.

Tungsten Effects on Soil Environments

Nikolay Strigul, Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA, Tel: 201-216-5681, Fax: 201-216-8303, Email:  nstrigul@stevens-tech.edu
Washington Braida, Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA, Tel: 201-216-5681, Fax: 201-216-8303, Email: wbraida@stevens-tech.edu
Dimitris Dermatas, Stevens Institute of Technology, Civil, Environmental, and Ocean Engineering Department, Castle Point on Hudson, Hoboken, NJ 07030, USA, Tel: 201-216-8926, Fax: 201-216-5352, Email: ddermata@stevens-tech.edu
Christos Christodoulatos, Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, USA, Tel: 201-216-5675, Fax: 201-216-8303, Email: christod@stevens-tech.edu
Michael Los, TACOM-ARDEC, US Army Heavy Metals Office, Picatinny Arsenal, Picatinny, NJ 07806, Tel: 973-724-7038, Fax: 973-724-2034, Email: mlos@pica.army.mil

Tungsten alloys have been used to manufacture different caliber ammunition and kinetic energy penetrators. However, information on the impacts of tungsten on environmental systems is very limited. The objective of this study was to investigate the effects of tungsten on soil community and soil-plant systems. Target compounds were chemical pure tungsten, ammunition grade tungsten, and common alloying elements such as nickel and cobalt. Several different techniques were utilized: soil respiration, TOC (total carbon) analysis, direct microscopic observation on the degradation of starch and micro-cellulose, and plant toxicity using ryegrass. Dissolution of munitions grade tungsten powder significantly acidified soil solution.  Other alloying elements behave different, cobalt increased soil pH while nickel reduced soil pH but not significantly.  Changes in the soil microbial community were analyzed by the spread plate dilution method. Tungsten powder and soluble tungsten were added to soil at ratio ranging from 0.01% to 10%. Tungsten has strong toxic effect on soil microbial community, soil microfauna (nematodes and mites) and plant growth. Tungsten mixed with soils at rates higher than 1% (w/w) inhibited glucose, micro-cellulose and starch degradation. The CO₂ evolution was raised several times in tungsten-polluted soils suggesting the death of a substantial fraction of soil organisms. After three months of incubation, TOC analysis shows that soil amended with 1% and 5% of tungsten (w/w) lost 5.9% and 10.5% of total carbon through CO₂ production, respectively. The changes on soil microbial community after tungsten amendment continue after several weeks. The death of 95% of soil bacteria was observed after 4 months in soils amended with 3% (w/w) of tungsten. The toxicity of the tungsten alloy components to environmental systems appears to follow the order munitions grade W @Co.>> Ni. 

Corrosion Behavior of Tungsten Alloys in the Environment

Abebayo Ogundipe, Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, Tel: 201-216-5329, Fax: 201-216-8303, Email: aogundip@stevens.edu
Washington Braida, Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030, Tel: 201-216-5681, Fax: 201-216-8303, Email: wbraida@stevens.edu
Dimitris Dermatas, Stevens Institute of Technology, Civil, Environmental, and Ocean Engineering Department, Castle Point on Hudson, Hoboken, NJ 07030, Tel: 201-216-8926, Fax: 201-216-5352, Email: ddermata@stevens-tech.edu
Christos Christodoulatos, Center for Environmental Systems, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030,  Tel: 201-216-5675, Fax: 201-216-8303, Email: christod@stevens-tech.edu
Michael Los, TACOM-ARDEC, US Army Heavy Metals Office, Picatinny Arsenal, Picatinny, NJ 07806, Tel: 973-724-7038, Fax: 973-724-2034, Email: mlos@pica.army.com

Tungsten-based alloys are being used or are under evaluation for potential use, in the manufacturing of kinetic energy penetrators for various munitions applications.  Tungsten heavy alloys are mainly composed of tungsten (88-95%) with nickel and cobalt making up usually the remaining fraction of the formulation.  Iron and copper may also be present depending on the particular alloy composition. Tungsten has a wide variety of stereochemistries and oxidation states, making its chemistry the most complex of the transition elements. The limited studies available in the literature on soil adsorption do not address the basic mechanisms of release and transport of tungsten and the effects of complexation on solubility and subsequent bioavailability. The rate of release of ions from the alloy surface and the formation of solid coatings is generally controlled by the redox phenomena prevailing in the surrounding medium.  Factors affecting the rate of corrosion in soils include the soil pH, redox potential, moisture content and its mineralogical and chemical composition. Corrosion of the metal alloys by exposing the solid surface to aqueous solutions or more realistically in soil matrices is currently under study. The corrosion behaviors of 5 munitions grade alloys of interest are being examined. The corrosion products deposited on the alloy surface and the thickness of the surface coating is determined by X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Aqua and oxo complexes of tungsten are of special interest for assessing its subsurface mobility. The dissolution of tungsten and the subsequent formation of condensed polytungstates involve complicated chemical processes. Characterization of the complexes formed as intermediate products of this process is attempted using FTIR techniques. Preliminary experimental results have suggested the presence of non-stoichiometric tungsten oxides as possible intermediates in the process. XRD analysis shows the presence of tungsten bronzes with general formula H_xWO₃.yH₂O and intermetallic compounds.

Evaluation of Phosphate Treatment Methods to Reduce Lead Mobility at Military Small Arms Training Ranges

Dr. R. Mark Bricka, Mississippi State University, Dave C. Swalm School of Chemical Engineering, PO Box 9595, Mississippi State, MS  39762, Tel: 662-325-1615, Fax:  662-325-2482, Email: Bricka@che.msstate.edu
Mr. Jason Darnell, Mississippi State University, Dave C. Swalm School of Chemical Engineering, PO Box 9595, Mississippi State, MS  39762, Tel: 662-325-1615, Fax:  662-325-2482, Email:  jed3@msstate.edu                     
Mr. Gene Fabian, US Army Aberdeen Test Center, Attn: CSTE-DTC-AT-SC-SL-F, 400 Colleran Rd, APG, MD  21005, Tel: 410-278-7421, Email: gfabian@atc.army.mil

The primary goal of the United States Military is to train and equip troops to maintain military readiness to defend the United States and its interests.  Small arms range (SAR) training represents a major element in keeping the military ready to accomplish this mission.

Projectiles utilized as part of SAR training have accumulated in the soil at the SARs as a result of many years of use.  These projectiles are composed of toxic metals.  The projectiles, with weathering, change form allowing the metals to migrate to surface and ground water sources.  Due to the toxicity associated with the metals, the SAR may pose a threat to humans and the environment.  Current lead remediation techniques are costly and inefficient thus new cost effective remediation techniques must be developed and implemented.

Studies show that the treatment of the soil with phosphate-based binders may react with the metals, which results in lowering the solubility of the lead and other metals.  The phosphate based-binders react with the metal ions, such as lead, to form insoluble metal phosphate complexes called pyromorphites as shown in equation 1.

10M²⁺ + 6H₂PO₄^- + 2OH^-     ®      M₁₀(PO₄)₆(OH₂) + 12H+    Eq (1).

Several types of phosphate binders can be used to form the desired pyromorphites, however, the kinetics of the reaction depend on the phosphate complex.  This may be due to the ability of the specific binder to mix efficiently in the contaminated soil or due to the reactive nature of the specific form of phosphate applied to the site.

This paper presents the results of a study to investigate the effect of phosphates on the lead contained in soils collected at military SAR training areas.  Laboratory evaluations consisted of adding various phosphates at different dosages to SAR samples.  After treatment the soils were subjected to a series of leaching tests.  The result of laboratory effort as well as the planned field activities will be presented.

Recovery and Recycling of Tungsten and Lead from Small Arms Firing Range Soils 

Michael F. Warminsky, P.E., AMEC Earth and Environmental, 285 Davidson Avenue, Suite 100, Somerset, NJ 08873, Tel: 732-302-9500 ext 126, Email: mike.warminsky@amec.com
Dr. Steven Larson, U.S. Army Engineer Research and Development Center, 3903 Halls Ferry Rd, Vicksburg, MS 39180, Tel: 601-634-3431, Email: larsons@wes.army.mil

A significant mass of tungsten has been used to produce 5.56 mm ammunition for use at military training facilities as a substitute for lead bullets.  The mass of tungsten used in fixed target/fixed firing position ranges has produced soils that are expected to contain tungsten in the percent by mass concentrations, in addition to legacy lead from past training.  The tungsten industry has been recycling tungsten materials from metal scrap for decades.  The reactivity of tungsten in water, especially in alkaline waters, is exploited in the recycling process.  Tungsten is treated with alkaline water to form soluble tungstates.  This water, laden with high concentrations of tungstates is then neutralized and solid ammonium para-tungstate is separated from the solution and used to produce tungsten metals.  Using the previously developed chemical recovery system coupled with state of the art soil washing techniques, a potential recovery system has been designed for removal of tungsten, as well as legacy lead, from small arms training range berms. 

Vertical Distribution and Speciation of Lead at a Recreational Firing Range in Eastern Massachusetts

Jack Duggan, Ph.D., P.E., Wentworth Institute of Technology, 550 Huntington Avenue, Boston, MA 02115, Tel: 617-989-4181, Fax: 617-989-4170, Email: dugganj@wit.edu
Ankit Dhawan, M.S. Candidate, Massachusetts College of Pharmacy and Health Sciences, 179 Longwood Avenue, Boston, MA02115, Email: ankit_dhawan@yahoo.com

A soil sampling and analysis study was performed to characterize the distribution and speciation of lead shot and lead species at a recreational skeet and trap range in Eastern Massachusetts.  Results indicate the majority of lead is present at 0-2” as both lead shot and lead shot fragments retained on #8 and #16 sieves.  While lead speciation in soils varied with soil cation exchange capacity (CEC), soil acidity and organic carbon content, carbonate species of lead were predominate in soils below a depth of 0-2”.  Concentrations of lead in respirable soil particles were also measured. 

Soil samples were collected in locations at four distances from shooting platforms including prior to, within and beyond the fall zone of the range.  A 0-6” core was collected from each sample location.  The core was separated into three sections (0-2”, 2-4” and 4-6”).  For each section, a particle size distribution was determined.  Samples from each sieved fraction were then analyzed for lead content. Lead shot and fragments from sieved fractions were also separated and quantified.

Lead analysis was performed by flame atomic absorption spectroscopy.  A sequential extraction procedure was performed to measure the speciation of lead in each sieved fraction.  The sequential extraction procedure was used to distinguish exchangeable, soluble, organic, carbonate, and residual forms of lead in each sample. 

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