Search NASA⌕ Search

SEARCH · Search NASA

Results for “Aqueous waste”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Supercritical waste oxidation of aqueous wastes

For aqueous wastes containing 1 to 20 wt% organics, supercritical water oxidation is less costly than controlled incineration or activated carbon treatment and far more efficient than wet oxidation. Above the critical temperature (374 C) and pressure (218 atm) of water, organic materials and gases are completely miscible with water. In supercritical water oxidation, organics, air and water are brought together in a mixture at 250 atm and temperatures above 400 C. Organic oxidation is initiated spontaneously at these conditions. The heat of combustion is released within the fluid and results in a rise in temperature 600 to 650 C. Under these conditions, organics are destroyed rapidly with efficiencies in excess of 99.999%. Heteroatoms are oxidized to acids, which can be precipitated out as salts by adding a base to the feed. Examples are given for process configurations to treat aqueous wastes with 10 and 2 wt% organics.

Modell, M.↗
NASA NTRSDate not supplied

Supercritical Water Oxidation and a Preliminary Concept for Lunar Application

Abstract: Water is a critical resource for crewed space exploration missions and reclamation of aqueous waste streams presents the only long-term viable option. Although early Artemis missions are considering water as part of the payload manifest, it would be extremely advantageous if follow-on missions were supplied—either in total or in part—by a reclamation technology that would operate autonomously between missions. An attractive technology is currently under ongoing research at NASA Glenn Research Center (GRC) that employs a Supercritical Water Oxidation (SCWO) process to destroy all hydrocarbons in the waste stream. Testing of an aqueous waste stream simulant, typical of what is generated on the International Space Station (ISS), has shown reductions in Total Organic Carbon (TOC) of greater than 99% with reactor residence times less than 30 s. Recent effort has been directed toward developing a conceptual design based on the current tubular reactor used in the evaluation of the conversion of SCWO. This conceptual design along with the results of recent SCWO conversion experiments will be presented. Recent design enhancements to achieve shorter residence times along with “production simulation” tests will be presented. The diagnostics used in assessing the extent of the waste conversion include a total organic carbon (TOC) analysis, Raman analyses, and measurements of pH, turbidity, and conductivity. Results obtained from the modified reactor configuration will also be compared to those of the Phase I configuration presented in earlier work.

SCWO↗
NASA NTRS2003

Lyophilization for Water Recovery From Solid Waste

This abstract describes the development of a solid waste treatment system designed for a near term human exploration mission. The technology being developed is an energy- efficient lyophilization technique that recovers water from spacecraft solid waste. In the lyophilization process water in an aqueous waste is frozen and then sublimed, resulting in the separation of the waste into a dried solid material and liquid water. This technology is ideally suited to applications where water recovery rates approaching 100% are desirable but production of CO, is not. Water contained within solid wastes accounts for approximately 3% of the total water balance. If 100% closure of the water loop is desired the water contained within this waste would need to be recovered. To facilitate operation in microgravity thermoelectric heat pumps have be used in place of traditional fluid cycle heat pumps. A mathematical model of a thermoelectric lyophilizer has been developed and used to generate energy use and processing rate parameters. The results of laboratory investigations and discussions with ALS program management have been used to iteratively arrive at a prototype design. This design address operational limitations which were identified in the laboratory studies and handling and health concerns raised by ALS program management. The current prototype design is capable of integration into the ISS Waste Collection System.

Flynn, Michael↗
NASA NTRS2004

Lyophilization -Solid Waste Treatment

This paper discusses the development of a solid waste treatment system that has been designed for a Mars transit exploration mission. The technology described is an energy-efficient lyophilization technique that is designed to recover water from spacecraft solid wastes. Candidate wastes include feces, concentrated brines from water processors, and other solid wastes that contain free water. The system is designed to operate as a stand-alone process or to be integrated into the International Space Station Waste Collection System. In the lyophilization process, water in an aqueous waste is frozen and then sublimed, separating the waste into a dried solid material and liquid water. The sublimed water is then condensed in a solid ice phase and then melted to generate a liquid product. In the subject system the waste solids are contained within a 0.2 micron bio-guard bag and after drying are removed from the system and stored in a secondary container. This technology is ideally suited to applications such as the Mars Reference Mission, where water recovery rates approaching 100% are desirable but production of CO2 is not. The system is designed to minimize power consumption through the use of thermoelectric heat pumps. The results of preliminary testing of a prototype system and testing of the final configuration are provided. A mathematical model of the system is also described.

Litwiller, Eric↗
NASA NTRS1990

Importance of biological systems in industrial waste treatment potential application to the space station

In addition to having applications for waste management issues on planet Earth, microbial systems have application in reducing waste volumes aboard spacecraft. A candidate for such an application is the space station. Many of the planned experiments generate aqueous waste. To recycle air and water the contaminants from previous experiments must be removed before the air and water can be used for other experiments. This can be achieved using microorganisms in a bioreactor. Potential bioreactors (inorganics, organics, and etchants) are discussed. Current technologies that may be applied to waste treatment are described. Examples of how biological systems may be used in treating waste on the space station.

Revis, Nathaniel↗
NASA NTRS1981

Functional magnetic microspheres

Functional magnetic particles are formed by dissolving a mucopolysaccharide such as chitosan in acidified aqueous solution containing a mixture of ferrous chloride and ferric chloride. As the pH of the solution is raised magnetite is formed in situ in the solution by raising the pH. The dissolved chitosan is a polyelectrolyte and forms micelles surrounding the granules at pH of 8-9. The chitosan precipitates on the granules to form microspheres containing the magnetic granules. On addition of the microspheres to waste aqueous streams containing dissolved ions, the hydroxyl and amine functionality of the chitosan forms chelates binding heavy metal cations such as lead, copper, and mercury and the chelates in turn bind anions such as nitrate, fluoride, phosphate and borate.

Yen, Shiao-Ping S.↗
NASA NTRS1997

Surfactant/Supercritical Fluid Cleaning of Contaminated Substrates

CFC's and halogenated hydrocarbon solvents have been the solvents of choice to degrease and otherwise clean precision metal parts to allow proper function. Recent regulations have, however, rendered most of these solvents unacceptable for these purposes. New processes which are being used or which have been proposed to replace these solvents usually either fail to remove water soluble contaminants or produce significant aqueous wastes which must then be disposed of. In this work, a new method for cleaning surfaces will be investigated. Solubility of typical contaminants such as lubricating greases and phosphatizing bath residues will be studied in several surfactant/supercritical fluid solutions. The effect of temperature, pressure, and the composition of the cleaning mixture on the solubility of oily, polar, and ionic contaminants will be investigated. A reverse micellar solution in a supercritical light hydrocarbon solvent will be used to clean samples of industrial wastes. A reverse micellar solution is one where water is dissolved into a non-polar solvent with the aid of a surfactant. The solution will be capable of dissolving both water-soluble contaminants and oil soluble contaminants. Once the contaminants have been dissolved into the solution they will be separated from the light hydrocarbon and precipitated by a relatively small pressure drop and the supercritical solvent will be available for recycle for reuse. The process will be compared to the efficacy of supercritical CO2 cleaning by attempting to clean the same types of substrates and machining wastes with the same contaminants using supercritical CO2. It is anticipated that the supercritical CO2 process will not be capable of removing ionic residues.

White, Gary L.↗
NASA NTRS2005

Development of a gravity-independent wastewater bioprocessor for advanced life support in space

Operation of aerobic biological reactors in space is controlled by a number of challenging constraints, mainly stemming from mass transfer limitations and phase separation. Immobilized-cell packed-bed bioreactors, specially designed to function in the absence of gravity, offer a viable solution for the treatment of gray water generated in space stations and spacecrafts. A novel gravity-independent wastewater biological processor, capable of carbon oxidation and nitrification of high-strength aqueous waste streams, is presented. The system, consisting of a fully saturated pressurized packed bed and a membrane oxygenation module attached to an external recirculation loop, operated continuously for over one year. The system attained high carbon oxidation efficiencies often exceeding 90% and ammonia oxidation reaching approximately 60%. The oxygen supply module relies on hydrophobic, nonporous, oxygen selective membranes, in a shell and tube configuration, for transferring oxygen to the packed bed, while keeping the gaseous and liquid phases separated. This reactor configuration and operating mode render the system gravity-independent and suitable for space applications.

NASA Discipline Life Support Systems↗
NASA NTRS1977

Catalytic oxidation of waste materials

Aqueous stream of human waste is mixed with soluble ruthenium salts and is introduced into reactor at temperature where ruthenium black catalyst forms on internal surfaces of reactor. This provides catalytically active surface to convert oxidizable wastes into breakdown products such as water and carbon dioxide.

Jagow, R. B.↗
NASA NTRS1993

Development of the Monolith Froth Reactor for Catalytic Wet Oxidation of CELSS Model Wastes

The aqueous phase oxidation of acetic acid, used as a model compound for the treatment of CELSS (Controlled Ecological Life Support System) waste, was carried out in the monolith froth reactor which utilizes two-phase flow in the monolith channels. The catalytic oxidation of acetic acid was carried out over a Pt/Al2O3 catalyst at temperatures and pressures below the critical point of water. The effect of externally controllable parameters (temperature, liquid flow rate, distributor plate orifice size, pitch, and catalyst distance from the distributor plate) on the rate of acetic acid oxidation was investigated. Results indicate reaction rate increased with increasing temperature and exhibited a maximum with respect to liquid flow rate. The apparent activation energy calculated from reaction rate data was 99.7 kJ/mol. This value is similar to values reported for the oxidation of acetic acid in other systems and is comparable to intrinsic values calculated for oxidation reactions. The kinetic data were modeled using simple power law kinetics. The effect of "froth" feed system characteristics was also investigated. Results indicate that the reaction rate exhibits a maximum with respect to distributor plate orifice size, pitch, and catalyst distance from the distributor plate. Fundamental results obtained were used to extrapolate where the complete removal of acetic acid would be obtained and for the design and operation of a full scale CELSS treatment system.

Fisher, John W.↗
NASA NTRS1995

Development of the Monolith Froth Reactor for Catalytic Wet Oxidation of CELSS Model Wastes

The aqueous phase oxidation of acetic acid, used as a model compound for the treatment of CELSS (Controlled Ecological Life Support System) waste, was carried out in the monolith froth reactor which utilizes two-phase flow in the monolith channels. The catalytic oxidation of acetic acid was carried out over a Pt/Al2O3 catalyst, prepared at The University of Tulsa, at temperatures and pressures below the critical point of water. The effect of externally controllable parameters (temperature, liquid flow rate, distributor plate orifice size, pitch, and catalyst distance from the distributor plate) on the rate of acetic acid oxidation was investigated. Results indicate reaction rate increased with increasing temperature and exhibited a maximum with respect to liquid flow rate. The apparent activation energy calculated from reaction rate data was 99.7 kJ/mol. This value is similar to values reported for the oxidation of acetic acid in other systems and is comparable to intrinsic values calculated for oxidation reactions. The kinetic data were modeled using simple power law kinetics. The effect of "froth" feed system characteristics was also investigated. Results indicate that the reaction rate exhibits a maximum with respect to distributor plate orifice size, pitch, and catalyst distance from the distributor plate. Fundamental results obtained were used to extrapolate where the complete removal of acetic acid would be obtained and for the design and operation of a full scale CELSS treatment system.

Abraham, Martin↗
NASA NTRS2003

The effect of drying and size reduction pretreatments on recovery of inorganic crop nutrients from inedible wheat residues

Inorganic nutrients can be easily recovered from ALS crop residue solid wastes by aqueous leaching. However, oven drying and milling pretreatment of these residues has been frequently required to accommodate crop scientists and facility storage limitations. As part of a research study that will compare three different bioreactor technologies for processing these wastes, we realized that different drying and size-reduction pretreatments had been utilized for each technology. This paper compares the effects of residue pretreatment on recovery of nutrients by leaching. Pretreatments included three drying methods [fresh, oven-dried (70 degrees C overnight), and freeze-dried] and two size reduction methods [chopped (2 cm length) and milled (2 mm diameter)]. Determination of mass balances (dry weight and ash content of solids) before and after leaching indicated solubilization was least for fresh residues (23% dry weight loss and 50% for ash loss), and most for freeze-dried residues (41-47% dry weight loss and nearly 100% for ash loss). Mineral recovery of major elements (NO3, PO4, K, Ca, and Mg) in leachates was poorest for fresh residues. P and K recovery in leachates were best for oven-dried residues and Ca, Mg, and N recovery best for freeze-dried residues. The differences in recovery for N, P, and K in leachates were minimal between chopping and milling and slightly better for Ca and Mg from milled residues.

NASA Center KSC↗
NASA NTRS2006

Diffusion Limited Supercritical Water Oxidation (SCWO) in Microgravity Environments

Tests designed to quantify the gravitational effects on thermal mixing and reactant injection in a Supercritical Water Oxidation (SCWO) reactor have recently been performed in the Zero Gravity Facility (ZGF) at NASA s Glenn Research Center. An artificial waste stream, comprising aqueous mixtures of methanol, was pressurized to approximately 250 atm and then heated to 450 C. After uniform temperatures in the reactor were verified, a controlled injection of air was initiated through a specially designed injector to simulate diffusion limited reactions typical in most continuous flow reactors. Results from a thermal mapping of the reaction zone in both 1-g and 0-g environments are compared. Additionally, results of a numerical model of the test configuration are presented to illustrate first order effects on reactant mixing and thermal transport in the absence of gravity.

Hicks, M. C.↗
NASA NTRS1977

Disposal of hypergolic propellants, phase 6 task 4. Disposal pond products

Waste monomethyl hydrazine scrubber liquor, consisting of aqueous solutions containing small amounts of CH4, Cl2, CH3Cl, CH2Cl2, and CHCl3 as well as large amounts of CH3OH is scheduled to be dumped in stabilization ponds along with nitrate and nitrite salt solutions obtained as waste liquors from the N2O4 scrubbers. The wastes are investigated as to the hazardous materials generated by such combinations of items as described as well as the finite lifetime of such materials in the stabilization ponds. The gas liquid chromatograph was used in the investigation. A series of experiments designed to convert nitrate and nitrite salts to the environmentally innocuous N2O and N2 using solar energy is reported. Results indicate that this solar conversion is feasible.

Cohenour, B. C.↗
NASA NTRS1994

Regenerating using aqueous cleaners with ozone and electrolysis

A new process converts organic oil and grease contaminates in used water based cleaners into synthetic surfactants. This permits the continued use of a cleaning solution long after it would have been dumped using previously known methods. Since the organic soils are converted from contaminates to cleaning compounds the need for frequent bath dumps is totally eliminated. When cleaning solutions used in aqueous cleaning systems are exhausted and ready for disposal, they will always contain the contaminates removed from the cleaned parts and drag-in from prior cleaning steps. Even when the cleaner is biodegradable these contaminants will frequently cause the waste cleaning solution to be a hazardous waste. Chlorinated solvents are rapidly being replaced by aqueous cleaners to avoid the new ozone-depletion product-labeling-law. Many industry standard halocarbon based solvents are being completely phased out of production, and their prices have nearly tripled. Waste disposal costs and cradle-to-grave liability are also major concerns for industry today. This new process reduces the amount of water and chemicals needed to maintain the cleaning process. The cost of waste disposal is eliminated because the water and cleaning compounds are reused. Energy savings result by eliminating the need for energy currently used to produce and deliver fresh water and chemicals as well as the energy used to treat and destroy the waste from the existing cleaning processes. This process also allows the cleaning bath to be maintained at the peak performance of a new bath resulting in decreased cycle times and decreased energy consumption needed to clean the parts. This results in a more efficient and cost effective cleaning process.

Mcginness, Michael P.↗
NASA NTRS1977

Reforming of glucose and wood at the critical conditions of water

Reforming of organics in aqueous solutions is being investigated as a potential waste treatment process. Earlier studies showed that glucose in water reacts to form a gaseous mixture of CO, H2, CH4, CO2, C2H6, and C2H4 in the vicinity of the critical conditions of water (374 C, 22 MPa). The earlier work has been extended to determine the effect of variations in temperature and feed concentration on the extent of gasification. The percent gasification decreases with increasing feed concentration, indicating an overall kinetic order less than unity. Surprisingly, the percent gasification decreases with increasing temperature. A number of preliminary experiments were conducted with maple sawdust feed, which was thought to be representative of complex organic wastes from paper and vegetable matter. Once again, no solid products were found under the critical conditions; the percent gasification ranged from 16 to 88 percent, depending on the feed composition and residence time.

Modell, M.↗
NASA NTRS2008

Performance Assessment of the Exploration Water Recovery System

A new water recovery system architecture designed to fulfill the National Aeronautics and Space Administration s (NASA) Space Exploration Policy has been tested at the Marshall Space Flight Center (MSFC). This water recovery system architecture evolved from the current state-of-the-art system developed for the International Space Station (ISS). Through novel integration of proven technologies for air and water purification, this system promises to elevate existing system optimization. The novel aspect of the system is twofold. First, volatile organic compounds (VOC) are removed from the cabin air via catalytic oxidation in the vapor phase, prior to their absorption into the aqueous phase. Second, vapor compression distillation (VCD) technology processes the condensate and hygiene waste streams in addition to the urine waste stream. Oxidation kinetics dictate that removing VOCs from the vapor phase is more efficient. Treating the various waste streams by VCD reduces the load on the expendable ion exchange and adsorption media which follows, as well as the aqueous-phase catalytic oxidation process further downstream. This paper documents the results of testing this new architecture.

Carter. D. Layne↗