Jacqueline Quinn

A two and half-year-performance evaluation of a field test on treatment of source zone tetrachloroethene and its chlorinated daughter products using emulsified zero valent iron nanoparticles

A field test of emulsified zero valent iron (EZVI) nanoparticles was conducted at Parris Island, SC, USA and was monitored for two and half years to assess the treatment of subsurface-source zone chlorinated volatile organic compounds (CVOCs) dominated by tetrachloroethene (PCE) and its chlorinated daughter products. Two EZVI delivery methods were used: pneumatic injection and direct injection. In the pneumatic injection plot, 2180 L of EZVI containing 225 kg of iron (Toda RNIP-10DS), 856 kg of corn oil, and 22.5 kg of surfactant were injected to remedy an estimated 38 kg of CVOCs. In the direct injection plot, 572 L of EZVI were injected to treat an estimated 0.155 kg of CVOCs. After injection of the EZVI, significant reductions in PCE and trichloroethene (TCE) concentrations were observed in downgradient wells with corresponding increases in degradation products including significant increases in ethene. In the pneumatic injection plot, there were significant reductions in the downgradient groundwater mass flux values for PCE (>85%) and TCE (>85%) and a significant increase in the mass flux of ethene. There were significant reductions in total CVOC mass (86%); an estimated reduction of 63% in the sorbed and dissolved phases and 93% reduction in the PCE DNAPL mass. There are uncertainties in these estimates because DNAPL may have been mobilized during and after injection. Following injection, significant increases in dissolved sulfide, volatile fatty acids (VFA), and total organic carbon (TOC) were observed. In contrast, dissolved sulfate and pH decreased in many wells. The apparent effective remediation seems to have been accomplished by direct abiotic dechlorination by nanoiron followed by biological reductive dechlorination stimulated by the corn oil in the emulsion.

Travel distance and transformation of injected emulsified zerovalent iron nanoparticles in the subsurface during two and half years

Nanoscale zerovalent iron (NZVI) such as Toda Kogyo RNIP-10DS has been used for site remediation, yet information is lacking regarding how far injected NZVI can travel, how long it lasts, and how it transforms to other minerals in a groundwater system. Previously we reported effective mass destruction of chlorinated ethenes dominated by tetrachloroethene (PCE) using emulsified zerovalent iron (EZVI) nanoparticles of RNIP-10DS in a shallow aquifer (1-6 m below ground surface, BGS) at Site 45, Marine Corps Recruit Depot, Parris Island, South Carolina, USA. Here we report test results on transport and transformation of injected EZVI in the subsurface. We employed two EZVI delivery methods: pneumatic injection and direct injection. Effective delivery of EZVI to the targeted zone was achieved with pneumatic injection showing a travel distance from injection points of up to 2.1 m and direct injection showing a travel distance up to 0.89 m. X-ray diffraction and scanning electron microscopy studies on particles harvested from well purge waters indicated that injected black colored NZVI (α-Fe(0)) was transformed largely to black colored cube-like and plate-like magnetites (Fe3O4, 0.1-1 μm, 0-9 months), then to orange colored irregularly shaped lepidocrocite (γ-FeOOH, 0.1-1 μm, 9 months to 2.5 years), then to yellowish lath-like goethite (α-FeOOH, 2-5 μm, 2.5 years) and ferrihydrite-like spherical particles (0.05-0.1 μm) in the top portion of the aquifer (1-2 m BGS). No α-Fe(0) was found in most monitoring wells three months after injection. The formed iron oxides appeared to have a wider range of particle size (submicron to 5 μm) than the pristine NZVI (35-140 nm). Injected NZVI was largely transformed to magnetite (0.1-1 μm) during two and half years in the lower portion of the aquifer (3-6 m).

Ultrasound pretreatment of elemental iron: kinetic studies of dehalogenation reaction enhancement and surface effects

This work presents data showing the kinetic improvement afforded by ultrasound pretreatment and illustrates the physical and chemical changes that take place at the iron surface. First-order rate constants improved as much as 78% with 2h of ultrasound pretreatment. Scanning electron microscopy (SEM) and surface area analysis were used for confirmation of the physical changes that take place after ultrasound was used on iron surfaces exposed to a variety of conditions. X-ray photoelectron spectroscopy was used to determine chemical surface characteristics before and after ultrasound use. SEM and surface area analysis showed that ultrasound use clears the iron surface of debris increasing the surface area up to 169%. In addition, exposure to ultrasound alters ratios of surface species, such as adventitious carbon to carbonyl carbon and iron to oxygen, and removed hydroxides thus making the iron more reactive to reductive dehalogenation.

The Use of Tribocharging in the Electrostatic Beneficiation of Lunar Simulant

The use of tribocharging as a potential method to provide sufficient charge to several different lunar simulants for electrostatic beneficiation was investigated. The objective was to determine whether specific minerals of interest (e.g., ilmenite) that are present in lunar regolith could be enriched in concentration by beneficiation that would therefore allow for more efficient extraction for in situ resource utilization use. The production of oxygen, water, and other resources on the Moon from raw materials is vital for future missions to the Moon. Successful separation of ilmenite was achieved for a prepared simulant (KSC-1), which is a mixture of pure commercially supplied pyroxene, olivine, feldspar, and ilmenite, in a 4 : 4 : 1 : 1 ratio, showing proof of concept when tribocharged against three different charging materials, namely, Al, Cu, and PTFE. Separation by chemical composition was also observed for existing lunar simulants JSC-1 and JSC-1A; however, the interpretation of the separation was difficult due to the complex mineralogy of the simulants compared to the simple prepared mixture.

Dechlorination of polychlorinated biphenyls using magnesium and acidified alcohols.

Polychlorinated biphenyls (PCBs) were widely used in industry until their regulation in the 1970s. However, due to their inherent stability, they are still a widespread environmental contaminant. A novel method of degradation of PCBs (via hydrodehalogenation) has been observed using magnesium powder, a carboxylic acid, and alcohol solvents and is described in this paper. The rates of degradation were determined while varying the type of acid (formic, acetic, propionic, butyric, valeric, benzoic, ascorbic, and phosphoric), the amount of magnesium from 0.05 to 0.25 g, the amount of acetic acid from 0.5 to 50 μL and the concentration of PCB-151 from 0.1 to 50 μg/mL, as well as the alcohol solvent (methanol, ethanol, propanol, butanol, octanol, and decanol). The results of these studies indicate that the most rapid PCB dechlorination is achieved using a matrix consisting of at least 0.02 g Mg/mL ethanol, and 10 μL acetic acid/mL ethanol in which case 50 ng/μL of PCB-151 is dechlorinated in approximately 40 min.

Introducing the Resource Prospector (RP) Mission

he Resource Prospector (RP) Mission is an in-situ resource utilization (ISRU) technology demonstration mission under study by NASA’s Human Exploration and Operations Mission Directorate’s (HEOMD’s) Advanced Exploration Systems (AES) Division. The mission, currently planned to launch in 2019, will demonstrate prospecting for volatiles and extraction of oxygen from lunar regolith as an ISRU demonstration. The mission will utilize the RESOLVE (Regolith & Environment Science and Oxygen & Lunar Volatile Extraction) payload, developed by NASA. RP will address key Strategic Knowledge Gaps (SKGs) for robotic and human exploration to the moon, Near Earth Asteroids (NEAs), and ultimately Mars. The concept of ‘strategic knowledge gaps’ for all potential human destinations was developed by HEOMD as a guide for Agency investments including robotic precursor missions and the SKGs were externally vetted and contributed to by all three analysis groups for the three key future human destinations: asteroids (Small Bodies Analysis Group or SBAG), the moon (Lunar Exploration Analysis Group or LEAG), and Mars (the Mars Exploration Program Analysis Group or MEPAG), and then vetted by the international space community via the International Space Exploration Coordination Group (ISECG).

The use of mechanical alloying for the preparation of palladized magnesium bimetallic particles for the remediation of PCBs

The kinetic rate of dechlorination of a polychlorinated biphenyl (PCB-151) by mechanically alloyed Mg/Pd was studied for optimization of the bimetallic system. Bimetal production was first carried out in a small-scale environment using a SPEX 8000M high-energy ball mill with 4-μm-magnesium and palladium impregnated on graphite, with optimized parameters including milling time and Pd-loading. A 5.57-g sample of bimetal containing 0.1257% Pd and ball milled for 3 min resulted in a degradation rate of 0.00176 min(-1)g(-1) catalyst as the most reactive bimetal. The process was then scaled-up, using a Red Devil 5400 Twin-Arm Paint Shaker, fitted with custom plates to hold milling canisters. Optimization parameters tested included milling time, number of ball bearings used, Pd-loading, and total bimetal mass milled. An 85-g sample of bimetal containing 0.1059% Pd and ball-milled for 23 min with 16 ball bearings yielded the most reactive bimetal with a degradation rate of 0.00122 min(-1)g(-1) catalyst. Further testing showed adsorption did not hinder extraction efficiency and that dechlorination products were only seen when using the bimetallic system, as opposed to any of its single components. The bimetallic system was also tested for its ability to degrade a second PCB congener, PCB-45, and a PCB mixture (Arochlor 1254); both contaminants were seen to degrade successfully.

Mauna Kea, Hawaii, as an Analog Site for Future Planetary Resource Exploration: Results from the 2010 ILSO-ISRU Field-Testing Campaign

The major advances in knowledge of extraterrestrial bodies come from in situ measurements on robotized measuring devices deployed by international space missions, for example, on the Moon and Mars. It is essential to test these instruments in environments on Earth thatbearacloseresemblancetoplanetaryconditions.Withintheframeworkofthe2010InternationalLunarSurfaceOperationInSituResource Utilization (2010 ILSO-ISRU) Analog Test, a suite of scientific instruments developed for in situ lunar research was field tested and cali- brated on the Mauna Kea volcano in Hawaii on January 27 to February 11, 2010. This site will beused as one ofthe future standard test sites to calibrate instruments forin situ lunarresearch.In 2010, atotalof eight scientificteams tested instrument capabilities at the test site.In this paper, a geological setting for this new field-test site, a description of the instruments that were tested during the 2010 ILSO-ISRU field campaign, and a short discussion of each instrument about the validity and use of the results obtained during the test are provided. These results will serve as reference for future test campaigns. DOI: 10.1061/(ASCE)AS.1943-5525.0000200.

Evaluation of Tribocharged Electrostatic Beneficiation of Lunar Simulant in Lunar Gravity

AbstractTribocharged electrostatic beneficiation of a lunar simulant and actual Apollo regolith has been shown to be successful under a high lunar vacuum in which various degrees of efficient particle separation and mineral enrichment of up to a few hundred percent were achieved. In this paper, electrostatic beneficiation of a lunar simulant at 1/6g, as run on reduced gravity flights (RGFs), is reported. Enrichment of the target mineral ilmenite was achieved as high as 65 and 106% in the two RGF flights undertaken, showing that tribocharged electrostatic beneficiation is a viable process in the lunar environment. It was also shown that the efficiency of the separation was a factor in the orientation of the apparatus in the aircraft because the force of gravity was not perpendicular to the plane of the apparatus during the flight parabolas.

Tribocharging Lunar Simulant in Vacuum for Electrostatic Beneficiation

Electrostatic beneficiation of lunar regolith has potential application for separating minerals for material processing on the moon. This paper describes the use of tribocharging lunar simulant prior to mineral grain separation. The lunar simulant JSC‐1 was sieved into five size fractions: 100μm for characterization, however only the 50–75μm fraction was passed through aluminum, copper and polytetrafluoroethylene (PTFE) inclined plane chargers. The amount of charge acquired by the simulant is dependant upon the difference in the work function of the charging material and the mineral grain composition of the simulant itself. Various charge‐to‐mass ratios (Q/M) for the different tribocharging materials were obtained for JSC‐1 in vacuum as well as in air. XPS, SEM and Raman spectroscopy were used to evaluate the JSC‐1 simulant before and after beneficiation. Results indicate notable changes in mineral composition between pre‐ and post‐beneficiation samples after only a sin...