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DOE OSTI2022

AmeriFlux FLUXNET-1F US-CF2 CAF-LTAR Cook West

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-CF2 CAF-LTAR Cook West. This is the FLUXNET version of the carbon flux data for the site US-CF2 CAF-LTAR Cook West produced by applying the standard ONEFlux (1F) software. Site Description - CF2 has operated since May 2017 at the R.J. Cook Agronomy Farm outside of Pullman, Washington, and monitors the conventionally tilled side of a paired-catchment study that is part of the Longterm Agroecosystem Research (LTAR) site common experiment. CF2 is located in “Cook West,” a field that has been in conventional tillage since prior to 1998 and constitutes the Prevalent treatment of the common experiment. In this case, conventional tillage involves chisel plowing after the winter wheat phase of rotations (approximately every 3-4 years) and occasional harrowing. CF2 is paired with the CF1 tower location in “Cook East,” which has been in no-till since 1998 and represents the Alternative treatment of the common experiment. Both fields are planted in the same crops every year. Cook Agronomy Farm is in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Crop rotations are wheat-based and include winter wheat, spring wheat, chickpea, spring canola, and winter peas. Wheat is the principal cash crop, with other crops grown in rotation for diversity, nutrient, and pest management. Soils are predominantly silt loam texture Mollisols in the Palouse, Thatuna, Naff soil series. The CF2 tower replaced US-RC2, which operated 2012-2016 in a neighboring field that was also conventionally tilled. CF2 and RC2 have distinct footprints, aspects, and soil series compositions.

Huggins, Dave↗

DOE OSTI2026

AmeriFlux FLUXNET-1F CA-CF2 Churchill Fen Site 2

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site CA-CF2 Churchill Fen Site 2. This is the FLUXNET version of the carbon flux data for the site CA-CF2 Churchill Fen Site 2 produced by applying the standard ONEFlux (1F) software. Site Description - Fen site dominated by sedges. Flat, high water table. Frozen for long periods each year. Close to Arctic Ocean coast so affected by land/sea breezes and coastal weather.

Tenuta, Mario [University of Manitoba]↗

DOE OSTI2020

Materials Data on CF2 by Materials Project

CF2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two difluoromethane molecules, two fluoroform molecules, and two fluoromethane molecules.

36 MATERIALS SCIENCE↗

DOE OSTI2020

AmeriFlux CA-CF2 Churchill Fen Site 2

This is the AmeriFlux version of the carbon flux data for the site CA-CF2 Churchill Fen Site 2. Site Description - Fen site dominated by sedges. Flat, high water table. Frozen for long periods each year. Close to Arctic Ocean coast so affected by land/sea breezes and coastal weather.

Tenuta, Mario↗

DOE OSTI2020

Materials Data on Sb2H10(CF2)3 by Materials Project

C3SbH10SbF6 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight C3SbH10 clusters and eight SbF6 clusters. In four of the C3SbH10 clusters, there are three inequivalent C+1.33- sites. In the first C+1.33- site, C+1.33- is bonded in a distorted trigonal non-coplanar geometry to one Sb and three H1+ atoms. The C–Sb bond length is 2.12 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the second C+1.33- site, C+1.33- is bonded in a distorted trigonal non-coplanar geometry to one Sb and three H1+ atoms. The C–Sb bond length is 2.12 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the third C+1.33- site, C+1.33- is bonded in a distorted trigonal non-coplanar geometry to one Sb and three H1+ atoms. The C–Sb bond length is 2.12 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. Sb is bonded in a tetrahedral geometry to three C+1.33- and one H1+ atom. The Sb–H bond length is 1.69 Å. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one Sb atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In four of the C3SbH10 clusters, there are three inequivalent C+1.33- sites. In the first C+1.33- site, C+1.33- is bonded in a distorted trigonal non-coplanar geometry to one Sb and three H1+ atoms. The C–Sb bond length is 2.12 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the second C+1.33- site, C+1.33- is bonded in a distorted trigonal non-coplanar geometry to one Sb and three H1+ atoms. The C–Sb bond length is 2.12 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. In the third C+1.33- site, C+1.33- is bonded in a distorted trigonal non-coplanar geometry to one Sb and three H1+ atoms. The C–Sb bond length is 2.12 Å. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. Sb is bonded in a tetrahedral geometry to three C+1.33- and one H1+ atom. The Sb–H bond length is 1.69 Å. There are ten inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one Sb atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C+1.33- atom. In each SbF6 cluster, Sb is bonded in an octahedral geometry to six F1- atoms. There are a spread of Sb–F bond distances ranging from 1.91–1.94 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Sb atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Sb atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Sb atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Sb atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Sb atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one Sb atom.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Quantitative evaluation of perfluorinated alkanethiol molecular order on gold surfaces

Self-assembled monolayers (SAMs) of perfluoroalkanethiols [CF3(CF2)xCH2CH2SH (x = 3, 5, 7, and 9)] on gold were characterized by x-ray photoelectron spectroscopy (XPS), near edge x-ray absorption fine structure (NEXAFS), and static time-of-flight secondary ion mass spectrometry (ToF-SIMS). Perfluoroalkanethiols of several chain lengths were synthesized using a known hydride reduction method for transforming commercially available perfluoroalkyliodides to corresponding perfluoroalkanethiols. This strategy provides improved product yields compared to other known routes based on hydrolysis from the common thioacetyl perfluoroalkyl intermediate. Angle-dependent XPS analysis revealed that CF3(CF2)xCH2CH2SH (x = 5, 7, and 9; F6, F8, and F10, respectively) SAMs on gold exhibited significant enrichment of the terminal CF3 group at the outer monolayer surface with the sulfur present as a metal-bound thiolate located at the monolayer-gold interface. XPS of the CF3(CF2)3CH2CH2SH (F4) monolayer revealed a thin film with a significant (>50%) amount of hydrocarbon contamination consistent with poorly organized monolayers, while the longest thiol (F10) showed XPS signals attributed to substantial ordering and anisotropy. ToF-SIMS spectra from all four SAMs contained molecular ions representative of the particular perfluorinated thiol used to prepare the monolayer. NEXAFS methods were used to determine degrees of ordering and average tilt for molecules comprising monolayers. The SAMs prepared from the longest (F10) thiols exhibited the highest degree of ordering with the molecular axis nearly perpendicular to the gold surface. The degree of ordering decreased significantly with decreasing length of the perfluorocarbon tail.

Biophysics↗

DOE OSTI2020

Materials Data on AgH9C7S2(OF)4 by Materials Project

AgC5H9(SO2)2(CF2)2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of four difluoromethane molecules and one AgC5H9(SO2)2 cluster. In the AgC5H9(SO2)2 cluster, Ag1+ is bonded in a 5-coordinate geometry to two S2- and three O2- atoms. Both Ag–S bond lengths are 2.49 Å. There are a spread of Ag–O bond distances ranging from 2.72–2.98 Å. There are five inequivalent C+0.86+ sites. In the first C+0.86+ site, C+0.86+ is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. The C–S bond length is 1.81 Å. In the second C+0.86+ site, C+0.86+ is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. All C–H bond lengths are 1.10 Å. The C–S bond length is 1.81 Å. In the third C+0.86+ site, C+0.86+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.28 Å) C–O bond length. In the fourth C+0.86+ site, C+0.86+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.23 Å) and one longer (1.31 Å) C–O bond length. In the fifth C+0.86+ site, C+0.86+ is bonded in a distorted water-like geometry to two H1+ and two S2- atoms. Both C–H bond lengths are 1.10 Å. There is one shorter (1.80 Å) and one longer (1.82 Å) C–S bond length. There are nine inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the fifth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.06 Å) and one longer (1.47 Å) H–O bond length. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and two C+0.86+ atoms. In the second S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Ag1+ and two C+0.86+ atoms. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Ag1+ and one C+0.86+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ag1+, one C+0.86+, and one H1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Ag1+ and one C+0.86+ atom. In the fourth O2- site, O2- is bonded in a water-like geometry to one C+0.86+ and one H1+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on AsC2S2(OF3)3 by Materials Project

(CF2)2AsSOF5SO2 crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of eight difluoromethane molecules, four sulfur dioxide molecules, and four AsSOF5 clusters. In each AsSOF5 cluster, As5+ is bonded in an octahedral geometry to one O2- and five F1- atoms. The As–O bond length is 2.02 Å. There are a spread of As–F bond distances ranging from 1.74–1.77 Å. S1+ is bonded in a single-bond geometry to one O2- atom. The S–O bond length is 1.55 Å. O2- is bonded in a distorted bent 120 degrees geometry to one As5+ and one S1+ atom. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one As5+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one As5+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on AgH8C7S2O2F7 by Materials Project

AgC4H8(SO)2(CF2)2CF3 crystallizes in the orthorhombic Pca2_1 space group. The structure is two-dimensional and consists of eight difluoromethane molecules; four fluoroform molecules; and one AgC4H8(SO)2 sheet oriented in the (0, 0, 1) direction. In the AgC4H8(SO)2 sheet, Ag1+ is bonded to three S2- and one O2- atom to form distorted corner-sharing AgS3O tetrahedra. All Ag–S bond lengths are 2.62 Å. The Ag–O bond length is 2.35 Å. There are four inequivalent C+0.86+ sites. In the first C+0.86+ site, C+0.86+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.27 Å) C–O bond length. In the second C+0.86+ site, C+0.86+ is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. The C–S bond length is 1.81 Å. In the third C+0.86+ site, C+0.86+ is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. There is two shorter (1.09 Å) and one longer (1.10 Å) C–H bond length. The C–S bond length is 1.82 Å. In the fourth C+0.86+ site, C+0.86+ is bonded in a distorted water-like geometry to two H1+ and two S2- atoms. Both C–H bond lengths are 1.10 Å. There is one shorter (1.81 Å) and one longer (1.83 Å) C–S bond length. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C+0.86+ atom. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to two equivalent Ag1+ and two C+0.86+ atoms to form distorted corner-sharing SAg2C2 tetrahedra. In the second S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to one Ag1+ and two C+0.86+ atoms. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Ag1+ and one C+0.86+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C+0.86+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on GeC4(BrF5)2 by Materials Project

GeBr2(CF2)2(CF3)2 crystallizes in the tetragonal P4_32_12 space group. The structure is zero-dimensional and consists of four dibromogermane molecules, eight difluoromethane molecules, and eight fluoroform molecules.

36 MATERIALS SCIENCE↗

DOE OSTI2021

AmeriFlux FLUXNET-1F US-CF1 CAF-LTAR Cook East

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-CF1 CAF-LTAR Cook East. This is the FLUXNET version of the carbon flux data for the site US-CF1 CAF-LTAR Cook East produced by applying the standard ONEFlux (1F) software. Site Description - CF1 has operated since May 2017 at the R.J. Cook Agronomy Farm outside of Pullman, Washington, and monitors the no-till side of a paired-catchment study that is part of the Longterm Agroecosystem Research (LTAR) site common experiment. CF1 is located in “Cook East,” a field that has been in no-till management since 1998, and represents the Alternative treatment of the LTAR common experiment. It is paired with the CF2 tower location in “Cook West,” which has been in conventional tillage since prior to 1998 and represents the Prevalent treatments of the common experiment. Cook Agronomy Farm is in the high precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Crop rotations are wheat-based and include winter wheat, spring wheat, chickpea, spring canola, and winter peas. Wheat is the principal cash crop, with other crops grown in rotation for diversity, nutrient, and pest management. Soils are predominantly silt loam texture Mollisols in the Palouse, Thatuna, Naff soil series. The CF1 tower replaced US-RC1, which operated 2012-2016 in a neighboring field that was also in no-till management since 1998. CF1 and RC1 have distinct footprints, aspects, and soil series compositions.

Phillips, Claire L.↗

DOE OSTI2026

AmeriFlux FLUXNET-1F US-RC2 Cook Agronomy Farm - Conventional Till

This is the AmeriFlux Management Project (AMP) created FLUXNET-1F version of the carbon flux data for the site US-RC2 Cook Agronomy Farm - Conventional Till. This is the FLUXNET version of the carbon flux data for the site US-RC2 Cook Agronomy Farm - Conventional Till produced by applying the standard ONEFlux (1F) software. Site Description - RC2 operated from 2013-2016 at the R.J. Cook Agronomy Farm, as part of a cluster of 5 towers (RC1 to RC5) operated for the Regional Approaches to Climate Change (REACCH) USDA-supported research project. The tower predates the Longterm Agroecosystem Research (LTAR) site common experiment, which was established in nearby fields at the Cook Agronomy Farm in 2017. Cook Agronomy Farm is in the high-precipitation agroecological zone of the Columbia Plateau’s dryland cropping region. Wheat-based crop rotations are grown annually. RC2 had conventional tillage management (reduced-till) since at least 1998. It was contrasted with RC1, which had no-till management over the same time period. RC2 captured the same tillage practices as the US-CF2 site established in 2017 as part of LTAR common experiment. However, the towers have distinct footprints, aspects, and soil series composition.

Chi, Jinshu [The Hong Kong University of Science a↗

DOE OSTI2025

PFAS Removal by Ion Exchange Resins: Background and Knowledge Gaps with Respect to the Hanford Site

Per- and polyfluoroalkyl substances (PFAS) have been a rising concern for the past two decades, with the United States Department of Defense and Environmental Protection Agency investing millions of dollars in research into remediation and clean-up technologies. Due to the environmental persistence, toxicity, biological uptake, and ongoing changes in both federal and state regulatory space, understanding the fate and transport of PFAS compounds has been of growing concern to the US Department of Energy (DOE). The DOE’s Hanford Site is investigating historical use of PFAS and will be doing site characterization for PFAS. Thus, PFAS have not yet been identified as a contaminant concern in regulatory documents. Based on historical records that mention the discharge of aqueous film-forming foam containing PFAS and having on-site fire stations (a risk factor for PFAS contamination), it seems likely that environmental releases of PFAS may have occurred. Pump and treat (P&T) remediation is the selected remedy for multiple groundwater contaminant plumes at Hanford. These P&T systems use ion exchange (IX) as a component of aboveground treatment, with the specific resins depending on the target contaminants. There is potential that these IX resins may be able to remove PFAS from groundwater, but investigation is needed to understand affinity/selectivity and removal capacity given the groundwater composition and the operating conditions. This report provides background on PFAS uses and chemistry, then provides a review of IX resin applications for PFAS, identifying knowledge gaps. Recommendations are provided regarding research needed to address knowledge gaps and acquire information needed to propose IX as a future PFAS remediation technology at the Hanford Site, as well as other U.S. Department of Energy sites. Generally, PFAS compounds are fluorinated substances that contain at least one fully fluorinated methyl or methylene carbon – with a few noted exceptions, any chemical with at least a perfluorinated methyl group (–CF3) or a perfluorinated methylene group (–CF2–) is a PFAS. These chemical compounds are characterized as non-biodegradable, non-reactive, non-photolytic, and hydrolysis resistant. This makes them highly recalcitrant within the environment, however polyfluoroalkyl materials are less recalcitrant as the carbon chains contain C–H bonds which are more easily broken than carbon – fluorine (C–F) bonds. The backbone carbon structures are commonly punctuated with a head group, the most well-known of them are perfluorooctanesulfonic acid and perfluorooctanoic acid, which possess a sulfonate and a carboxylate group, respectively. IX resins are marketed for the removal of PFAS from water systems and industrial water, however, the mechanism of removal is not as well understood as for anion or cation removal. A better understanding of the mechanism of removal would enable the development of IX resins that have improved specificity for PFAS removal. Four knowledge gaps were identified: 1) the effect of dissolved ions on the IX resin PFAS removal effectiveness, 2) the effect of additional primary contaminants of concern (PCOCs) or secondary contaminants of concern (SCOCs) on the effectiveness of PFAS via IX resin, 3) the mechanisms of PFAS removal from water, and 4) practical solutions to IX resin regeneration and waste disposal.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗