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At least 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Microwave-Mediated Extraction of Critical Metals from LED E-Waste

This study introduces a microwave-assisted technique for extracting critical minerals from LED electronic waste. The process begins with microwave irradiation, which thermally decomposes the LED’s plastic lens into a brittle, charred residue. During this stage, the LED chip undergoes deflagration—being rapidly ejected from the reflective cavity and becoming embedded within the decomposed lens material. Consequently, the chip is encapsulated in the resulting charred residue. This composite, consisting of the charred lens and the LED chip, can be easily separated from the metallic pins (Fe, Ni, Ag), which remain almost undamaged. Subsequent calcination of the charred material in air exposes the materials making up the LED chip, which contain critical metals (e.g., Ga, As, In, Y, Au). These metals are then extracted through a two-step acid leaching process involving aqua regia followed by hot concentrated hydrochloric acid, yielding them in potentially recoverable forms. The synergistic effect of microwave irradiation and acid treatment achieves an average extraction efficiency of 96% for critical metals. Notably, this approach enables complete and loss-free recovery of the LED chip, offering a practical and efficient solution for LED e-waste recycling.

Bourlinos, Athanasios B.↗
NASA NTRS2013

The Pinnacles of Callisto

Many regions of Callisto feature an unusual landscape consisting of rolling dark plains with interspersed bright knobs (pinnacles) and ridges. In earlier work we interpreted the dark plains as dusty, mass-wasted residue from sublimation from volatile-rich bedrock and the bright knobs (often crater rims) as water ice accumulations at locations sheltered from thermal reradiation from the dusty residue. We simulated evolution of Callisto's craters as a combination of bedrock volatile sublimation, mass wasting of the dark, non-coherent residue, and redeposition of ice, and concluded that the ice pinnacles and ridges might be underlain by tens to hundreds of meters of ice. Here we report the initial work of a new study of pinnacles addressing additional questions: 1) Is there an evolutionary sequence starting, e.g., from a cratered initial surface through growth and formation of a dust mantle and pinnacles, to eventual loss of ice to sublimation resulting in just a dark, dusty surface? 2) What determines the areal density and spatial scale of pinnacles - volatile content of bedrock, crater density, surface age, broad-scale topographic setting? 3) Are pinnacles still forming? Several observations address these questions. In a few places scattered high-albedo blocks approx. 25-60 m in diameter occur in the vicinity of large icy pinnacles. We interpret these blocks to be remnants from the collapse of tall pinnacles that were undermined by mass wasting. Some high-relief icy knobs have developed a skeletonized planform due to mass wasting by avalanching, or perhaps to seeding of new sites of ice deposition on mass-wasted ice blocks. Some areas nearly lack fresh craters with well-defined ejecta and ice-free rims. This may imply rapid transformation of fresh craters by sublimation, mass wasting, and ice reprecipitation. In other areas small sharp-rimmed craters occur which lack ice pinnacles, but the craters nonetheless lack visible ejecta sheets. Our preliminary interpretation is that mass wasting is very efficient on Callisto, or alternatively the dust cover is very thick and lacks competent coarse materials.

bedrock volatile sublimation↗
DOE OSTI2021

Cesium Batch Contact Equilibrium Testing of Crystalline Silicotitanate (CST) Sieve Cuts in SRS Average Simulant and Examination of CST Samples Aged in Caustic and Simulant in Support of Tank Closure Cesium Removal 1A (TCCR-1A)

Batch contact testing to determine cesium equilibrium loading on Crystalline Silicotitanate ion exchange media in Savannah River Site Average Waste Simulant at 25 °C indicated that smaller diameter particles isolated by sieving pretreated CST media may load slightly higher (<10%) amounts of cesium, though the differences are within analytical uncertainty. In addition, ion exchange media sub-samples stored in 2-4 M NaOH and caustic simulant solutions for ~2.5 years were examined by optical microscopy and the 3 M NaOH sample was also analyzed to determine whether changes in the particle size distribution occurred during storage. No visual indications of particle attrition or agglomeration were observed for any sample. Particle size analysis indicated that a slight decrease occurred in the average particle diameter following contact with 3 M NaOH (541 µm average diameter versus 566 µm for the pretreated CST prior to contact). A small increase (from 0 to <0.5 wt. %) in the number of particles ranging from 271 and 322 µm was also observed for the CST sample contacted with 3 M NaOH relative to a sample of the original pretreated material. However, this small change could be due to sub-sampling differences or analytical uncertainty. It does not appear that small particles are formed to a significant degree during CST caustic contact or that small particles which do form (presumably from attrition of larger particles during pretreatment) load significantly more cesium than the bulk material. Minimal other negative consequences were observed associated with CST extended caustic or simulant contact, except for the tendency for more concentrated salt solutions to form some salt crystals which deposit on the media over time.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

OWL Release Process

The Online Waste Library (OWL) provides one consolidated source of information on Department of Energy-managed wastes likely to require deep geologic disposal. With the release of OWL Version 1.0 in fiscal year (FY) 2019, much of the FY2020 work involved developing the OWL change control process and the OWL release process. These two processes (in draft form) were put into use for OWL Version 2.0, which was released in early FY2021. With the knowledge gained, the OWL team refined and documented the two processes in two separate reports. This report addresses the release process starting with a definition of release management in Section 2. Section 3 describes the Information Technology Infrastructure Library (ITIL) framework, part of which includes the three different environments used for release management. Section 4 presents the OWL components existing in the different environments and provides details on the release schedule and procedures.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Decontamination of urban surfaces contaminated with radioactive materials and consequent onsite recycling of the waste water

Enhancing rapid remediation strategies is paramount for recovery after a large-scale nuclear contamination event in an urban environment. Some current strategies recommend use of readily available equipment, materials, and facilities to expedite recovery. For example, applying pressurized water to contaminated surfaces may effectively remove radioactive contamination. In this study, a commercial power washer removes soluble forms of 152 Eu 3 + , 85 Sr 2 + , and 137 Cs + contamination from common porous building materials, and computer simulations characterize the recycling of the resultant contaminated wash water. Pressure washing the porous building materials under spray conditions typical with do-it-yourself units improved decontamination factors (DFs) for 152 Eu compared to low-pressure application of tap water (majority of two-tailed t-test p-values < 0.1), but pressure did not improve DFs for 137 Cs or 85 Sr. For both pressurized and low-pressure applications, adding potassium ions (K + ) to promote ion exchange reactions produced significantly higher DFs for tested radionuclides on asphalt, brick, and concrete. The resultant contaminated wash water can be processed through self-prepared chemical filtration beds of clay and sand. Modeled in a prior study, the beds yielded linear trends (R 2 > 0.98) in sensitivity analyses between most bed configuration variables and bed performance variables, permitting flexible ad-hoc bed design. The experimental and simulation results led to estimates of the remediation rate and waste generated after cleaning 250 m 2 of cesium-contaminated concrete from the combined deployment of a power washer and two different mobile treatment beds. Furthermore, the first treatment bed was designed to reduce treatment time and processed 1900 L of wash solution in 70 min using 880 kg of clay/sand infill material. Designed to reduce the solid waste generated, the second bed processed the same solution volume in 1040 min (17 h) using 170 kg of clay/sand infill material. The results of this analysis warrant further investigation of power washing with recycled salt solution as an effective rapid decontamination method with manageable waste.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1974

Raw Liquid Waste Treatment System and Process

A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, suspended in the sewage water is first separated from the water, in which at least organic matter remains dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material adsorbs the organic matter dissolved in the water and is thereafter supplied in a counter flow direction and combined with the incoming raw sewage to at least facilitate the separation of the non-dissolved settleable materials from the sewage water. Carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

Humphrey, M. F.↗
NASA NTRS1980

Raw liquid waste treatment process

A raw sewage treatment process is disclosed in which substantially all the non-dissolved matter, which is suspended in the sewage water is first separated from the water, in which at least organic matter is dissolved. The non-dissolved material is pyrolyzed to form an activated carbon and ash material without the addition of any conditioning agents. The activated carbon and ash material is added to the water from which the non-dissolved matter was removed. The activated carbon and ash material absorbs organic matter and heavy metal ions, it is believed, are dissolved in the water and is thereafter supplied in a counter current flow direction and combined with the incoming raw sewage to facilitate the separation of the non-dissolved settleable materials from the sewage water. The used carbon and ash material together with the non-dissolved matter which was separated from the sewage water are pyrolyzed to form the activated carbon and ash material.

Humphrey, Marshall F.↗
DOE OSTI2021

OWL Change Control Process

The Online Waste Library (OWL) provides a consolidated source of information on Department of Energy-managed radioactive waste likely to require deep geologic disposal. With the release of OWL Version 1.0 in fiscal year 2019 (FY2019), much of the FY2020 work involved developing the OWL change control process and the OWL release process. These two processes (in draft form) were put into use for OWL Version 2.0, which was released in early FY2021. With the knowledge gained, the OWL team refined and documented the two processes in two separate reports. This report focuses on the change control process and discusses the following: (1) definitions and system components; (2) roles and responsibilities; (3) origin of changes; (4) the change control process including the Change List, Task List, activity categories, implementation examples, and checking and review; and (5) the role of the re lease process in ensuring changes in the Change List are incorporated into a public release.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Electrocatalytic Valorization into H2 and Hydrocarbons of an Aqueous Stream Derived from Hydrothermal Liquefaction

Electrocatalytic oxidation is an attractive process for valorizing the carbon and removal of nitrogen present in the aqueous waste streams at ambient conditions. Here, we evaluated the electrocatalytic oxidation as a function of applied potential over a commercial Pt electrode of aqueous waste stream generated via hydrothermal liquefaction. We validated the conversion of quantifiable carbon (e.g., carboxylic acids, alpha hydroxyacids, alcohols, ketones, amides) and unquantifiable carbon as well as nitrogen removal. The unquantifiable carbon was valorized to quantifiable short chain organic molecules (e.g., acetic). Model studies showed that carboxylic acids, alcohol and ketones converted following (non-) Kolbe chemistry. Amides and alpha hydroxyacids formed carboxylic acids that subsequently converted via (non-) Kolbe chemistry. Ammonia was oxidized into N2. The reaction rate varied for each molecule family with carboxylic acids and ammonia having the highest reaction rates. The main reaction products from the electrocatalytic oxidation at the anode were volatile, short chain hydrocarbons (i.e., olefins, paraffins) and CO generated via Kolbe chemistry, while H2 was generated at the cathode. The parallel denitrification, valorization of carbon, and H2 generation of the aqueous waste can replace and simplify the current unit operations used in a commercial hydrothermal liquefaction process. The high operation potential required to drive the electrocatalytic reaction is responsible for high operation costs; however, they can be either partially subsidized with sale of excess H2 at the current DOE goal of $2/kg H2. Thus, the present work shows how electrocatalytic oxidation can be used to valorize aqueous waste streams into volatile hydrocarbons and H2.

Electrocatalytic oxidation, Aqueous waste valoriza↗
DOE OSTI2024

Direct Feed High-Level Waste APPS Model Glass Testing (DFHLW APPS) Matrix

This report summarizes the data collected during the batching and melting of the Direct Feed High-Level Waste APPS Model Glass Matrix (DFHLW APPS) to serve as a quality-assured validation of the Aspen Process Performance Simulation (APPS) formulation method. Of 15 glasses tested, 12 satisfied all target property constraints. Two glasses, APPS-05 and -06, formed nepheline on canister centerline cooling heat-treatment and failed the Product Consistency Test response limits. Glass APPS-07-2 formed unacceptably high concentrations of crystals (primarily Na3Nd(PO4)2) when heat treated at 950 °C. All other glasses were found to be satisfactory. The measured property values were compared to predicted values from a set of current models. In many cases the current models were found to be inadequate for design of DFHLW glasses. These models are being adjusted to correct for mispredictions. Other models, e.g., density, toxicity characteristic leaching procedure, and sulfur solubility, are adequate for formulation of DFHLW glasses.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Upcycling waste PET into functional multiblock copolymers through controlled macromolecular design

Poly(ethylene terephthalate) (PET) oligomers derived from glycolysis depolymerization were converted into multiblock copolymers through diisocyanate-mediated coupling with dihydroxy-terminated oligomers, enabling precise control over copolymer sequence distribution, connectivity, and mechanical performance. Here, we demonstrate that telechelic PET oligomers isolated directly from depolymerized consumer waste can serve as reactive building blocks for the formation of segmented multiblock copolymers, eliminating the need to revert to monomeric feedstocks. Dihydroxy-terminated PET oligomers (Mw ≈ 8 kg mol−1) were coupled with poly(ethylene oxide) (PEO, Mw ≈ 4 kg mol−1) to form PET-PEO multiblock copolymers with high molar mass (Mw ≈ 160 kg mol−1). We further show that the timing of end-capping reactions provides a key control parameter that governs the competition between chain extension and termination, thereby dictating the resulting multiblock architecture and molecular-weight evolution. Evaluation of their mechanical properties reveals that virgin PET exhibits high modulus (∼3 GPa) and strength (43 MPa) but limited ductility (<10% elongation). In contrast, PET–PEO multiblock copolymers retain comparable tensile strength (44 MPa), albeit while exhibiting dramatically enhanced ductility (>90% elongation), forming tougher materials with efficient stress transfer between the rigid PET domains and the flexible PEO segments. When incorporated into PET/PEO blends at low loadings, the multiblock copolymers serve as effective compatibilizers, yielding materials with an intermediate modulus (1.1–1.2 GPa) and improved elongation compared to uncompatibilized blends. Furthermore, the presence of PEO blocks increases water uptake and gas permeability relative to virgin PET, reflecting the tunability of molecular transport through the copolymeric blocks. To our knowledge, this represents the first report of PET–PEO multiblock copolymers derived from post-consumer PET for gas transport applications. These results demonstrate that multiblock copolymer formation from telechelic PET oligomers provides a versatile platform for tailoring the mechanical and transport behavior of polyester-based materials through controlled macromolecular design and establishes a generalizable strategy for transforming consumer plastic waste into functional segmented polymers without requiring complete depolymerization to monomers.

Watson-Sanders, Shelby [Department of Chemistry, U↗
DOE OSTI2026

Knowledge-Based Hazardous Waste Determinations for Solar Photovoltaic (PV) Modules: A Foundational Study

This report explores using "generator knowledge" to determine whether a solar photovoltaic (PV) module must be managed as hazardous waste prior to recycling or landfilling. Generator knowledge is a legal term and existing regulatory pathway for making a hazardous waste determination that has been used by other industries but is a relatively unknown option to the PV industry. In the United States, a hazardous waste determination often acts as a pre-requisite to recycle or landfill a PV module. The results of the hazardous waste determination dictate whether the PV module must be managed as hazardous waste or nonhazardous solid waste. Managing a PV module as hazardous waste requires compliance with stringent U.S. federal and state hazardous waste law. In addition to increased management costs, which can be ten times higher, legal liability for PV modules regulated as hazardous waste is also heightened with both civil and criminal penalties for noncompliance which includes making an inaccurate or faulty hazardous waste determination. The most common reason a PV module would be regulated as hazardous is if it contains a regulated metal in an amount that equals or exceeds the toxicity characteristic limits. To determine whether a PV module exhibits a hazardous characteristic, the regulated person/entity must "apply knowledge...in light of the materials and processes used." In the absence of adequate knowledge to determine whether the PV module is hazardous, it must be tested using Test Method 1311 Toxicity Characteristic Leaching Procedure (TCLP) or an equivalent EPA-approved method. Although TCLP is the predominant method used to today to make a hazardous waste determination for PV modules, evidence from this study concludes it is not practical to TCLP test every PV module even in a single utility-scale installation, and a scalable solution is needed. This study finds that knowledge-based hazardous waste determinations may allow a regulated person/entity to make a hazardous waste determination for more than one PV module at one time - making this regulatory pathway a potential scalable solution. Through legal analysis and interviews with 44 experts, the authors explore what it means to make an accurate knowledge-based hazardous determination for PV modules considering sources and forms of information as well as potential limitations. The work aims to provide a foundation for building consensus on whether knowledge-based hazardous determinations are a viable, scalable industry approach for solar.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2022

Self-contained, automated, long-term sensor system for monitoring of soil and water nutrients in fields

An automated, fieldable ion-selective sensor system for frequent detection of nutrients in soils or water is set forth. In one aspect, an integrated small form-factor housing includes a battery, processor, a fluid manipulation unit and reservoirs, and a chemical species detection cell. A flow-through sampling head can be connected to the detection cell and a waste reservoir by flexible tubing sealingly connected at opposite ends of the tube. In one aspect, improved performance of the ion-selective sensor includes adding an ion-to-electron transfer interlayer between an ion-selective membrane and its working electrode. In one aspect, the sensor is solid-state and uses printed polymeric composite of POT-MoS$_{2}$. The use of a porous tube for a sampling head and fluid connection at opposite ends allows not only fluid to be removed from the head to the detection cell for measurement but also flow in an opposite direction and out to a waste reservoir to clean and reset for a next sample measurement.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Bona fide upcycling strategy of anhydride cured epoxy and reutilization of decomposed dual monomers into multipurpose applications

Waste epoxy materials become an enormous problem to society and the environment. The advantages of epoxy resins derive from their rigid and chemically stable networks, but these qualities also make them difficult to dispose of or recycle. In this work, we demonstrated an efficient degradation of anhydride cured epoxy resin by aminolysis in aminoethanol without using any catalysts. The epoxy resin was fully decomposed at 160 °C in 4 h, resulting in two distinct high purity monomers (HHPA-OH and BPA-OH). To fully realize this upcycling approach, The BPA-OH was used to synthesize a polyurethane coating with an excellent glass transition temperature (88.9 °C), scratch hardness (8H), gouge hardness (6H), adhesive strength (5B), and strong solvent resistance. The HHPA-OH with two hydroxyl groups was reacted with methacrylic anhydride to form a dimethacrylate monomer which was then used as a viable crosslinker for photo-curable 3D printing thermosetting polymer with tensile strength as high as 64 MPa and impact strength of 4.86 kJ/m 2 . This work demonstrates a feasible pathway to convert anhydride cured epoxy waste to new monomeric recyclates for superior polymer products.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Conformal High-Power-Density Half-Heusler Thermoelectric Modules: A Pathway toward Practical Power Generators

Thermoelectric generators (TEGs) exploiting the Seebeck effect provide a promising solution for waste heat recovery. Among the large number of thermoelectric (TE) materials, half-Heusler (hH) alloys are leading candidates for medium- to high-temperature power generation applications. However, the fundamental challenge in this field has been inhomogeneous material properties at large wafer diameters, insufficient power output from the modules, and rigid form factors of TE modules. This has restricted the transition of TEGs in practical applications for over three decades. Here, we successfully demonstrate large diameter wafers with uniform TE properties, high-power conformal hH TE modules for high-temperature application, and their direct integration on flue gas platforms, such as cylindrical tubes, to form large area flexible TEGs. This new conformal architecture design provides a breakthrough toward medium-/high-temperature TEGs over the conventional BiTe- and polymer-based flexible TEG design. In this work, a variable fill factor and greater flexibility due to the conformal design result in higher device performance as compared to conventional rigid TEG devices. Modules with 72-couple hH legs exhibit a device high-power-density of 3.13 W cm-2 and a total output power of 56.6 W under a temperature difference of 570 degrees C. These results provide a promising pathway toward widespread utilization of thermoelectric technology into the waste heat recovery application and will have a significant impact on the development of practical thermal to electrical converters.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Cesium exhibits different mesoscale segregation and ion pairing than lithium, sodium, or potassium in concentrated alkaline aqueous nitrite solutions

Understanding ion pairing in concentrated alkaline electrolytes facilitates the prediction and control of chemical processes in nuclear waste. While sodium is the dominant alkali metal in such systems, cesium often exhibits distinct bulk behavior relative to lighter alkali cations. Aqueous mixtures of cesium hydroxide and sodium nitrite were compared to alkali hydroxide analogs using small-angle x-ray scattering, revealing that cesium disrupts the sodium nitrite electrolyte structure, forming cesium-rich domains. This mesoscale segregation contrasts with the near-ideal mixing observed in other mixed hydroxide–nitrite systems. Raman spectroscopy indicates cesium–nitrite ion pairing, evidenced by vibrational shifts distinct from those associated with sodium. Multinuclear magnetic resonance spectroscopy further supports cesium–nitrite and cesium–hydroxide association, revealing a distinct local environment for nitrite in cesium-containing solutions. Together, these findings show that cesium promotes a unique solution structure dominated by specific ion pairing within segregated domains. This structural organization may influence radical generation pathways in high-ionic-strength alkaline media relevant to nuclear waste processing and management.

Nienhuis, Emily T. [Pacific Northwest National Lab↗
NASA NTRS1989

Logistics resupply and emergency crew return system for Space Station Freedom

Sometime in the late 1990's, if all goes according to plan, Space Station Freedom will allow the United States and its cooperating partners to maintain a permanent presence in space. Acting as a scientific base of operations, it will also serve as a way station for future explorations of the Moon and perhaps even Mars. Systems onboard the station will have longer lifetimes, higher reliability, and lower maintenance requirements than seen on any previous space flight vehicle. Accordingly, the station will have to be resupplied with consumables (air, water, food, etc.) and other equipment changeouts (experiments, etc.) on a periodic basis. Waste materials and other products will also be removed from the station for return to Earth. The availability of a Logistics Resupply Module (LRM), akin to the Soviet's Progress vehicle, would help to accomplish these tasks. Riding into orbit on an expendable launch vehicle, the LRM would be configured to rendezvous autonomously and dock with the space station. After the module is emptied of its cargo, waste material from the space station would be loaded back into it. The module would then begin its descent to a recovery point on Earth. Logistics Resupply Modules could be configured in a variety of forms depending on the type of cargo being transferred. If the LRM's were cycled to the space station in such a way that at least one vehicle remained parked at the station at all times, the modules could serve double duty as crew emergency return capsules. A pressurized LRM could then bring two or more crew-persons requiring immediate return (because of health problems, system failure, or unavoidable catastrophes) back to Earth. Large cost savings would be accrued by combining the crew return function with a logistics resupply system.

Ahne, D.↗
NASA NTRS1999

Review of historical monitoring data on Techa River contamination

The Mayak Production Association was the first Russian site for the production and separation of plutonium. The extensive increase in plutonium production during 1948-1955, as well as the absence of reliable waste-management technology, resulted in significant releases of liquid radioactive effluent into the rather small Techa River. This resulted in chronic external and internal exposure of about 30,000 residents of riverside communities; these residents form the cohort of an epidemiologic investigation. Analysis of the available historical monitoring data indicates that the following reliable data sets can be used for reconstruction of doses received during the early periods of operation of the Mayak Production Association: Temporal pattern of specific beta activity of river water for several sites in the upper Techa region since July 1951; average annual values of specific beta activity of river water and bottom sediments as a function of downstream distance for the whole river since 1951; external gamma-exposure rates near the shoreline as a function of downstream distance for the whole Techa River since 1952; and external gamma-exposure rate as a function of distance from the shoreline for several sites in the upper and middle Techa since 1951.

NASA Discipline Radiation Health↗