Modelling gas generation in radioactive waste repositories

International Nuclear Information System (INIS)

Agg, P.J.

1992-07-01

In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (Author)

Radioactive waste gas processing systems

International Nuclear Information System (INIS)

Kita, Kaoru; Minemoto, Masaki; Takezawa, Kazuaki.

1981-01-01

Purpose: To effectively separate and remove only hydrogen from hydrogen gas-containing radioactive waste gases produced from nuclear power plants without using large scaled facilities. Constitution: From hydrogen gas-enriched waste gases which contain radioactive rare gases (Kr, Xe) sent from the volume control tank of a chemical volume control system, only the hydrogen is separated in a hydrogen separator using palladium alloy membrane and rare gases are concentrated, volume-decreased and then stored. In this case, an activated carbon adsorption device is connected at its inlet to the radioactive gas outlet of the hydrogen separator and opened at its outlet to external atmosphere. In this system, while only the hydrogen gas permeates through the palladium alloy membrane, other gases are introduced, without permeation, into the activated carbon adsorption device. Then, the radioactive rare gases are decayed by the adsorption on the activated carbon and then released to the external atmosphere. (Furukawa, Y.)

Gas formation in drum waste packages of Paks NPP

International Nuclear Information System (INIS)

Molnar, M.; Palcsu, L.; Svingor, E.; Szanto, Z.; Futo, I.; Ormai, P.

2000-01-01

Gas composition measurements have been carried out by mass spectrometry analysis of samples taken from the headspace of ten drum waste packages generated and temporarily stored at Paks NPP. Four drums contained compacted solid waste, three drums were filled with grouted (solidified) sludge and three drums contained solid waste without compaction. The drums have been equipped with a special gas outlet system to make repeated sampling possible. Based on the first measurements significant differences in the gas composition and the rate of gas generation among the drums were found. (author)

Slurry growth and gas retention in synthetic Hanford waste

International Nuclear Information System (INIS)

Bryan, S.A.; Pederson, L.R.; Scheele, R.D.

1992-09-01

This work seeks to establish chemical and physical processes responsible for the generation and retention of gases within waste from a particular high-level waste tank on the Hanford Site, Tank 101-SY, through the use of synthetic wastes on a laboratory scale. The goal of these activities is to support the development of mitigation/remediation strategies for Tank 101-SY. Laboratory studies of aged synthetic waste have shown that gas generation occurs thermally at a significant level at current tank temperatures. Gas compositions include the same gases produced in actual tank waste, primarily N 2 , N 2 O, and H 2 . Gas stoichiometries have been shown to be greatly influenced by several organic and inorganic constituents within the synthetic waste. Retention of gases in the synthetic waste is in the form of bubble attachment to solid particles

Gas generation from transuranic waste degradation: an interim assessment

International Nuclear Information System (INIS)

Molecke, M.A.

1979-10-01

A review of all available, applicable data pertaining to gas generation from the degradation of transuranic waste matrix material and packaging is presented. Waste forms are representative of existing defense-related TRU wastes and include cellulosics, plastics, rubbers, concrete, process sludges, and mild steel. Degradation mechanisms studied were radiolysis, thermal, bacterial, and chemical corrosion. Gas generation rates are presented in terms of moles of gas produced per year per drum, and in G(gas) values for radiolytic degradation. Comparison of generation rates is made, as is a discussion of potential short- and long-term concerns. Techniques for reducing gas generation rates are discussed. 6 figures, 10 tables

Postoperative environmental anesthetic vapour concentrations following removal of the airway device in the operating room versus the postanesthesia care unit.

Science.gov (United States)

Cheung, Sara K; Özelsel, Timur; Rashiq, Saifee; Tsui, Ban C

2016-09-01

This study was designed to compare waste anesthetic gas (WAG) concentrations within patients' breathing zones after removal of the patient's airway device in the postanesthesia care unit (PACU) vs in the operating room (OR). Following Research Ethics Board approval and patient consent, we recruited patients undergoing surgery who received volatile anesthesia via an endotracheal tube or supraglottic airway. Patients had their airway device removed in the OR or in the PACU depending on the attending anesthesiologist's preference. Upon the patient's arrival in the PACU, concentrations of exhaled sevoflurane and desflurane were measured at their breathing zone (i.e., 15 cm from the patient's mouth and nose) using a single-beam infrared spectrophotometer. Seventy patients were recruited during the five-month study period. The median [interquartile range] WAG levels in the patients' breathing zones were higher when their airway devices were removed in the PACU vs in the OR. The WAG levels for sevoflurane were 0.7 [0.4-1.1] parts per million (ppm) vs 0.5 [0.4-0.7] ppm, respectively; median difference, 0.3; 95% confidence interval (CI), 0.1 to 0.6; P = 0.04. The WAG levels for desflurane were 2.4 [1.2-3.4] ppm vs 4.1 [2.5-5.2] ppm, respectively; median difference, 1.5; 95% CI, 0.3 to 2.7; P = 0.04. After a volatile-based anesthetic, our results suggest that removal of the airway device in the PACU vs in the OR increases the amount of waste anesthetic gas in a patient's breathing zone and thus potentially in the PACU nurse's working zone.

Radiolytic gas generation from cement-based waste hosts for DOE low-level radioactive wastes

International Nuclear Information System (INIS)

Dole, L.R.; Friedman, H.A.

1986-01-01

Using cement-based immobilization binders with simulated radioactive waste containing sulfate, nitrate, nitrite, phosphate, and fluoride anions, the gamma- and alpha-radiolytic gas generation factors (G/sub t/, molecules/100 eV) and gas compositions were measured on specimens of cured grouts. These tests studied the effects of; (1) waste composition; (2) the sample surface-to-volume ratio; (3) the waste slurry particle size; and (4) the water content of the waste host formula. The radiolysis test vessels were designed to minimize the ''dead'' volume and to simulate the configuration of waste packages

MOCVD waste gas treatment

International Nuclear Information System (INIS)

Geelen, A. van; Bink, P.H.M.; Giling, L.J.

1993-01-01

A large scale production of GaAs based solar cells with MOCVD will give rise to a considerable use of arsine. Therefore a gas treatment system is needed to convert the waste gases into less toxic compounds. In this study seven different gas treatment systems for MOCVD are compared by quantifying the environmental aspects. The systems are divided in wet systems, adsorption systems and thermal systems. The smallest amount of waste is produced by adsorption and thermal systems. Adsorption systems use the smallest amount of energy. The amount of primary materials used for the equipment varies per system. All systems are safe, but adsorption systems are simplest. At the moment, adsorption systems are probably the best choice from an environmental point of view. Nevertheless thermal systems have some potential advantages which make them interesting for the future

Estimating retained gas volumes in the Hanford tanks using waste level measurements

International Nuclear Information System (INIS)

Whitney, P.D.; Chen, G.; Gauglitz, P.A.; Meyer, P.A.; Miller, N.E.

1997-09-01

The Hanford site is home to 177 large, underground nuclear waste storage tanks. Safety and environmental concerns surround these tanks and their contents. One such concern is the propensity for the waste in these tanks to generate and trap flammable gases. This report focuses on understanding and improving the quality of retained gas volume estimates derived from tank waste level measurements. While direct measurements of gas volume are available for a small number of the Hanford tanks, the increasingly wide availability of tank waste level measurements provides an opportunity for less expensive (than direct gas volume measurement) assessment of gas hazard for the Hanford tanks. Retained gas in the tank waste is inferred from level measurements -- either long-term increase in the tank waste level, or fluctuations in tank waste level with atmospheric pressure changes. This report concentrates on the latter phenomena. As atmospheric pressure increases, the pressure on the gas in the tank waste increases, resulting in a level decrease (as long as the tank waste is open-quotes softclose quotes enough). Tanks with waste levels exhibiting fluctuations inversely correlated with atmospheric pressure fluctuations were catalogued in an earlier study. Additionally, models incorporating ideal-gas law behavior and waste material properties have been proposed. These models explicitly relate the retained gas volume in the tank with the magnitude of the waste level fluctuations, dL/dP. This report describes how these models compare with the tank waste level measurements

Assessment of gas flammability in transuranic waste container

International Nuclear Information System (INIS)

Connolly, M.J.; Loehr, C.A.; Djordjevic, S.M.; Spangler, L.R.

1995-01-01

The Safety Analysis Report for the TRUPACT-II Shipping Package [Transuranic Package Transporter-II (TRUPACT-II) SARP] set limits for gas generation rates, wattage limits, and flammable volatile organic compound (VOC) concentrations in transuranic (TRU) waste containers that would be shipped to the Waste Isolation Pilot Plant (WIPP). Based on existing headspace gas data for drums stored at the Idaho National Engineering Laboratory (INEL) and the Rocky Flats Environmental Technology Site (RFETS), over 30 percent of the contact-handled TRU waste drums contain flammable VOC concentrations greater than the limit. Additional requirements may be imposed for emplacement of waste in the WIPP facility. The conditional no-migration determination (NMD) for the test phase of the facility required that flame tests be performed if significant levels of flammable VOCs were present in TRU waste containers. This paper describes an approach for investigating the potential flammability of TRU waste drums, which would increase the allowable concentrations of flammable VOCS. A flammability assessment methodology is presented that will allow more drums to be shipped to WIPP without treatment or repackaging and reduce the need for flame testing on drums. The approach includes experimental work to determine mixture lower explosive limits (MLEL) for the types of gas mixtures observed in TRU waste, a model for predicting the MLEL for mixtures of VOCS, hydrogen, and methane, and revised screening limits for total flammable VOCs concentrations and concentrations of hydrogen and methane using existing drum headspace gas data and the model predictions

Preventing Buoyant Displacement Gas Release Events in Hanford Double-Shell Waste Tanks

Energy Technology Data Exchange (ETDEWEB)

Meyer, Perry A.; Stewart, Charles W.

2001-01-01

This report summarizes the predictive methods used to ensure that waste transfer operations in Hanford waste tanks do not create waste configurations that lead to unsafe gas release events. The gas release behavior of the waste in existing double-shell tanks has been well characterized, and the flammable gas safety issues associated with safe storage of waste in the current configuration are being formally resolved. However, waste is also being transferred between double-shell tanks and from single-shell tanks into double-shell tanks by saltwell pumping and sluicing that create new wastes and waste configurations that have not been studied as well. Additionally, planning is underway for various waste transfer scenarios to support waste feed delivery to the proposed vitrification plant. It is critical that such waste transfers do not create waste conditions with the potential for dangerous gas release events.

A prospective-controlled study of pregnant veterinary staff exposed to inhaled anesthetics and X-rays

International Nuclear Information System (INIS)

Shuhaiber, S.; Radee, I. C.; Sakkar, M.; Koren, G.; Einarson, A.

2002-01-01

Most veterinary staff are women of reproductive age. They are exposed to 'waste' anesthetic gas and ionizing radiation in their workplace, which may endanger fetal safety. Presently, exposure of female veterinary staff to these health hazards has not been adequately addressed in the medical literature. Our primary objective was to investigate the incidence of major malformations associated with occupational exposure to inhaled anesthetics and/or radiation among pregnant veterinary staff. The secondary objective was to determine the rates of other adverse outcomes. We prospectively collected data on and followed-up women occupationally exposed to inhaled anesthetics and/or radiation in veterinary practices in Ontario, and compared them to controls matched for maternal age gestational age at the time of call to the Motherisk Program. A total of 95 women wee prospectively enrolled and followed-up. Among the participants there were 87 (93.5%) and 88 (92.8%) live births in the study and control groups, respectively. There were 4 (4.8%) major birth defects in the study group and 3 (3.4%) in the control group. The rates of spontaneous abortion were also similar, 6 (6.4%) cases in the study group and 7(7.4%) cases in the control group. These results suggest that Ontario female veterinary staff exposed to inhaled anesthetics and/or radiation do not seem to be at an increased risk for major malformations above baseline risk. (author)

Continuous organic waste digester and methane gas generator

Energy Technology Data Exchange (ETDEWEB)

Araneta, V.A.

1979-01-01

A patent on the construction of a utility model of an industrial product of a continuous organic-waste digester and methane-gas generator is described. It comprises an airtight chamber to receive slurry of organic waste; a gas-water scrubber to purge carbon dioxide, odor-omitting gases and froth or scrum from newly formed methane gas evolving from said slurry of organic wastes; and two dually functioning slurry-feed and -discharge pipes connected to a reversible pump. It has one pipe with an opening at the base of an airtight chamber and the other pipe with up-ended openings below the fluid level of the slurry to be accumulated in the airtight chamber.

An innovative technique to improve safety of volatile anesthetics suction from the cardiopulmonary bypass circuit

Directory of Open Access Journals (Sweden)

Francesco De Simone

2017-01-01

Full Text Available Context: Myocardial injury during cardiac surgery on cardiopulmonary bypass (CPB is a major determinant of morbidity and mortality. Preclinical and clinical evidence of dose- and time-related cardioprotective effects of volatile anesthetic drugs exist and their use during the whole surgery duration could improve perioperative cardiac protection. Even if administering volatile agents during CPB are relatively easy, technical problems, such as waste gas scavenging, may prevent safe and manageable administration of halogenated vapors during CPB. Aims: The aim of this study is to improve the safe administration of volatile anesthesia during CPB. Settings and Design: Tertiary teaching hospital. Subjects and Methods: We describe an original device that collects and disposes of any volatile anesthetic vapors present in the exit stream of the oxygenator, hence preventing its dispersal into the operating theatre environment and adaptively regulates pressure of oxygenator chamber in the CPB circuit. Results: We have so far applied a prototype of this device in more than 1300 adult cardiac surgery patients who received volatile anesthetics during the CPB phase. Conclusions: Widespread implementation of scavenging system like the one we designed may facilitate the perfusionist and the anesthesiologist in delivering these cardioprotective drugs with beneficial impact on patients' outcome without compromising on safety.

Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

International Nuclear Information System (INIS)

Souza, Kátina M.; Braz, Leandro G.; Nogueira, Flávia R.; Souza, Marajane B.; Bincoleto, Lahis F.; Aun, Aline G.; Corrente, José E.; Carvalho, Lídia R.; Braz, José Reinaldo C.; Braz, Mariana G.

2016-01-01

Highlights: • Anesthesiologists exposed to the most commonly used anesthetic gases were evaluated. • No alterations were detected for lymphocyte DNA damage detected by the comet assay. • Decreased frequencies of basal cells were detected in exfoliated buccal cells (BMCyt). • Increased frequencies of micronucleus and cytotoxicity were observed in BMCyt assay. • Anesthesiologists have genomic instability due to occupational exposure. - Abstract: Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N 2 O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N 2 O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170 ppm for N 2 O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and pyknosis, and

Occupational exposure to anesthetics leads to genomic instability, cytotoxicity and proliferative changes

Energy Technology Data Exchange (ETDEWEB)

Souza, Kátina M.; Braz, Leandro G.; Nogueira, Flávia R.; Souza, Marajane B.; Bincoleto, Lahis F.; Aun, Aline G. [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil); Corrente, José E.; Carvalho, Lídia R. [Instituto de Biociências de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Bioestatística, Botucatu (Brazil); Braz, José Reinaldo C. [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil); Braz, Mariana G., E-mail: mgbraz@hotmail.com [Faculdade de Medicina de Botucatu, UNESP − Univ Estadual Paulista, Departamento de Anestesiologia, Botucatu (Brazil)

2016-09-15

Highlights: • Anesthesiologists exposed to the most commonly used anesthetic gases were evaluated. • No alterations were detected for lymphocyte DNA damage detected by the comet assay. • Decreased frequencies of basal cells were detected in exfoliated buccal cells (BMCyt). • Increased frequencies of micronucleus and cytotoxicity were observed in BMCyt assay. • Anesthesiologists have genomic instability due to occupational exposure. - Abstract: Data on the genotoxic and mutagenic effects of occupational exposure to the most frequently used volatile anesthetics are limited and controversial. The current study is the first to evaluate genomic instability, cell death and proliferative index in exfoliated buccal cells (EBC) from anesthesiologists. We also evaluated DNA damage and determined the concentrations of the anesthetic gases most commonly used in operating rooms. This study was conducted on physicians who were allocated into two groups: the exposed group, which consisted of anesthesiologists who had been exposed to waste anesthetic gases (isoflurane, sevoflurane, desflurane and nitrous oxide − N{sub 2}O) for at least two years; and the control group, which consisted of non-exposed physicians matched for age, sex and lifestyle with the exposed group. Venous blood and EBC samples were collected from all participants. Basal DNA damage was evaluated in lymphocytes by the comet assay, whereas the buccal micronucleus (MN) cytome (BMCyt) assay was applied to evaluate genotoxic and cytotoxic effects. The concentrations of N{sub 2}O and anesthetics were measured via a portable infrared spectrophotometer. The average concentration of waste gases was greater than 5 parts per million (ppm) for all of the halogenated anesthetics and was more than 170 ppm for N{sub 2}O, expressed as a time-weighted average. There was no significant difference between the groups in relation to lymphocyte DNA damage. The exposed group had higher frequencies of MN, karyorrhexis and

A review of literature relevant to gas production in radioactive waste

International Nuclear Information System (INIS)

Norris, G.H.

1987-11-01

A review of relevant recent papers on gas generation in low-level wastes and intermediate-level wastes is presented. Chemical, microbiological, radiolytic and thermal reactions are considered for both unconditioned wastes and wastes conditioned in cement, or bitumen, or polymer. Possible reaction mechanisms are identified and the effects of temperature and pressure are evaluated. Estimations of the production of combustible gases (which also have the potential to form explosive mixtures) have been taken from the literature. The implications of gas production for pressurisation (and possible rupture) of waste drums and of a repository are assessed. Waste-treatment schemes for the reduction of gas-generation capacity of several waste-types are highlighted. Recommendations for further work are summarised. (author)

Treatment of off-gas from radioactive waste incinerators

International Nuclear Information System (INIS)

1989-01-01

An effective process reducing volume of radioactive wastes is incineration of combustible wastes. Appropriate design of the off-gas treatment system is necessary to ensure that any releases of airborne radionuclides into the environment are kept below acceptable limits. In many cases, the off-gas system must be designed to accommodate chemical constituents in the gas stream. The purpose of this publication is to provide the most up-to-date information regarding off-gas treatment as well as an account of some of the developments so as to aid users in the selection of an integrated system for a particular application. The choice of incinerator/off-gas system combination depends on the wastes to be treated, as well as other factors, such as regulatory requirements. Current problems and development needs are discussed. Following comprehensive discussions of the various factors affecting a choice, various incinerator and off-gas treatment systems are recommended for the various types of wastes that may be treated: low PVC content solid, high PVC content solid, organic liquid and resins. The economics or costs of the off-gas system and an evaluation of the overall cost effectiveness of incineration or direct burial is not discussed in detail. This publication is specifically directed toward technical aspects and addresses: incineration types and origin, sources and characteristics of off-gas streams; descriptions of available technologies for off-gas treatment; basic component design requirements and component description; operational experience of plants in active operation and their current practices; legal aspects and safety requirements; remaining problems to be solved and development trends in plant design and component structure. This report seeks to broaden and enhance the understanding of the developed technology and to indicate areas where improvements can be made by further research and development. 110 refs

Safe Management of Waste Generated during Shale Gas Operations

Science.gov (United States)

Kukulska-Zając, Ewa; Król, Anna; Holewa-Rataj, Jadwiga

2017-04-01

Exploration and exploitation of hydrocarbon deposits, regardless of their type, are connected with the generation of waste, which may have various environmental effects. Such wastes may pose a serious risk to the surrounding environment and public health because they usually contain numerous potentially toxic chemicals. Waste associated with exploration and exploitation of unconventional hydrocarbon deposits is composed of a mixture of organic and inorganic materials, the qualitative and quantitative composition of which changes widely over time, depending on numerous factors. As a result the proper characteristic of this type of waste is very important. Information gained from detailed chemical analyses of drilling chemicals, drilling wastes, and flowback water can be used to manage shale gas-related wastes more appropriately, to develop treatment methods, to store the waste, and assess the potential environmental and health risk. The following paper will focus mainly on the results of research carried out on waste samples coming from the unconventional hydrogen exploration sites. Additionally, regulatory frameworks applicable to the management of wastes produced during this type of works will be discussed. The scope of research concerning physicochemical parameters for this type of wastes will also be presented. The presented results were obtained during M4ShaleGas project realization. The M4ShaleGas project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 640715.

Evaluation of greenhouse gas emissions from waste management approaches in the islands.

Science.gov (United States)

Chen, Ying-Chu

2017-07-01

Concerns about waste generation and climate change have attracted worldwide attention. Small islands, which account for more than one-sixth of the global land area, are facing problems caused by global climate change. This study evaluated the greenhouse gas emissions from five small islands surrounding Taiwan. These islands - Penghu County, Liuqui Island, Kinmen County, Matsu Island and Green Island - have their own waste management approaches that can serve as a guideline for waste management with greenhouse gas mitigation. The findings indicate that the total annual greenhouse gas emissions of the islands ranged from 292.1 to 29,096.2 [metric] tonne CO 2 -equivalent. The loading waste volumes and shipping distances were positively related to greenhouse gas emissions from transportation. The greenhouse gas emissions from waste-to-energy plants, mainly carbon dioxide and nitrous oxide, can be offset by energy recovery (approximately 38.6% of greenhouse gas emissions from incineration). In addition, about 34% and 11% of waste generated on the islands was successfully recycled and composted, respectively. This study provides valuable insights into the applicability of a policy framework for waste management approaches for greenhouse gas mitigation.

Status and integration of studies of gas generation in Hanford wastes

International Nuclear Information System (INIS)

Pederson, L.R.; Bryan, S.A.

1996-10-01

The purpose of this report is to review recent progress in determining the mechanism, kinetics, and stoichiometry of gas generation in Hanford waste tanks. Information has been gathered from the results of (1) laboratory studies with simulated wastes; (2) laboratory studies with actual waste core samples (Tanks SY-101 and SY-103); (3) studies of thermal and radiolytic reactions in the gas phase; (4) gas solubility evaluations; and (5) in-tank gas composition data. The results of laboratory studies using simulated wastes, which were aimed at determining chemical mechanisms responsible for gas generation, are summarized in Section 2. Emphasized are findings from work performed at the Georgia Institute of Technology (GIT), which was conducted under subcontract to Pacific Northwest National Laboratory (PNNL) and completed in FY 1996. Thermally activated pathways for the decomposition of hydroxyethylethylene-diaminetriacetic acid (HEDTA, trisodium salt) in simulated wastes were established by this work, among other accomplishments

Status and integration of studies of gas generation in Hanford wastes

Energy Technology Data Exchange (ETDEWEB)

Pederson, L.R.; Bryan, S.A.

1996-10-01

The purpose of this report is to review recent progress in determining the mechanism, kinetics, and stoichiometry of gas generation in Hanford waste tanks. Information has been gathered from the results of (1) laboratory studies with simulated wastes; (2) laboratory studies with actual waste core samples (Tanks SY-101 and SY-103); (3) studies of thermal and radiolytic reactions in the gas phase; (4) gas solubility evaluations; and (5) in-tank gas composition data. The results of laboratory studies using simulated wastes, which were aimed at determining chemical mechanisms responsible for gas generation, are summarized in Section 2. Emphasized are findings from work performed at the Georgia Institute of Technology (GIT), which was conducted under subcontract to Pacific Northwest National Laboratory (PNNL) and completed in FY 1996. Thermally activated pathways for the decomposition of hydroxyethylethylene-diaminetriacetic acid (HEDTA, trisodium salt) in simulated wastes were established by this work, among other accomplishments.

The Influence of Allocation on the Carbon Footprint of Electricity Production from Waste Gas, a Case Study for Blast Furnace Gas

Directory of Open Access Journals (Sweden)

Joeri Van Mierlo

2013-03-01

Full Text Available Producing electricity from waste gas is an after treatment for waste gas while recovering the energy content. This paper addresses the methodology to calculate the effect that waste gas energy recovery has on lowering the impact of climate change. Greenhouse gases are emitted while burning the waste gas. However, a thorough study should include the production of the feedstock as well as the production of the infrastructure. A framework is developed to calculate the environmental impact of electricity production from waste gas with a life cycle approach. The present paper has a twofold purpose: to assess the climate change impact of generating electricity with blast furnace gas (BFG as a waste gas from the steel industry; and to establish a sensitivity assessment of the environmental implications of different allocation rules.

Boundaries matter: Greenhouse gas emission reductions from alternative waste treatment strategies for California’s municipal solid waste

DEFF Research Database (Denmark)

Vergara, Sintana E.; Damgaard, Anders; Horvathc, Arpad

2011-01-01

How waste is managed – whether as a nuisance to be disposed of, or as a resource to be reused – directly affects local and global environmental quality. This analysis explores the GHG benefits of five treatment options for residual municipal solid waste (MSW) in California: Business As Usual...... landfills. Using two different waste LCA models, EASEWASTE (a Danish model) and WARM (a U.S. model), we find that improved biogenic waste management through anaerobic digestion and waste reduction can lead to life-cycle GHG savings when compared to Business As Usual. The magnitude of the benefits depends...... strongly on a number of model assumptions: the type of electricity displaced by waste-derived energy, how biogenic carbon is counted as a contributor to atmospheric carbon stocks, and the landfill gas collection rate. Assuming that natural gas is displaced by waste-derived energy, that 64% of landfill gas...

Feasibility of waste gas turbogenerators on motor ships

Energy Technology Data Exchange (ETDEWEB)

Steczek, M

1979-01-01

Using the waste gas energy, on any motor ship, electrical energy can be generated by means of a vapour cycle process without fuel costs. In the article, it is shown that engine performance on such a waste gas turbo generator can generate the power needed on board for operating the ship. This technical investigation is followed by a feasibility calculation which shows that such an installation is paid off very quickly with today's fuel costs.

The causes of the municipal solid waste and the greenhouse gas emissions from the waste sector in the United States.

Science.gov (United States)

Lee, Seungtaek; Kim, Jonghoon; Chong, Wai K O

2016-10-01

The United States generated approximately 730kg of waste per capita in 2013, which is the highest amount of waste among OECD countries. The waste has adverse effects to human health and the environment. One of the most serious adverse effects is greenhouse gas emissions, especially methane (CH4), which causes global warming. However, the United States' amount of waste generation is not decreasing, and the recycling rate is only 26%, which is lower than other OECD countries. In order to decrease waste generation and greenhouse gas emissions, identifying the causality of the waste generation and greenhouse gas emissions from waste sector should be made a priority. The research objective is to verify whether the Environmental Kuznets Curve relationship is supported for waste generation and GDP across the U.S. Moreover, it also confirmed that total waste generation and recycling of waste influences carbon dioxide emissions from the waste sector. Based on the results, critical insight and suggestions were offered to policymakers, which is the potential way to lower the solid waste and greenhouse gas emissions from the waste sector. This research used annually based U.S. data from 1990 to 2012, and these data were collected from various data sources. To verify the causal relationship, the Granger causality test was applied. The results showed that there is no causality between GDP and waste generation, but total waste and recycling generate significantly increasing and decreasing greenhouse gas emissions from the waste sector, respectively. This implies that waste generation will not decrease even if GDP increases. And, if waste generation decreases or the recycling rate increases, greenhouse gas emission will decrease. Based on these results, increasing the recycling rate is first suggested. The second suggestion is to break the causal relationship between MSW and greenhouse gas emission from the waste sector. The third is that the U.S. government should benchmark a

Evaluation of Gas Retention in Waste Simulants: Tall Column Experiments

Energy Technology Data Exchange (ETDEWEB)

Schonewill, Philip P.; Gauglitz, Phillip A.; Shimskey, Rick W.; Denslow, Kayte M.; Powell, Michael R.; Boeringa, Gregory K.; Bontha, Jagannadha R.; Karri, Naveen K.; Fifield, Leonard S.; Tran, Diana N.; Sande, Susan; Heldebrant, David J.; Meacham, Joseph E.; Smet, Dave; Bryan, Wesley E.; Calmus, Ronald B.

2014-05-16

Gas generation in Hanford’s underground waste storage tanks can lead to gas accumulation within the layer of settled solids (sludge) at the tank bottom. The gas, which typically has hydrogen as the major component together with other flammable species, is formed principally by radiation-driven chemical reactions. Accumulation of these gases within the sludge in a waste tank is undesirable and limits the amount of tank volume for waste storage. Further, accumulation of large amounts of gas in the sludge may potentially result in an unacceptable release of the accumulated gas if the sludge-layer density is reduced to less than that of the overlying sludge or that of the supernatant liquid. Rapid release of large amounts of flammable gases could endanger personnel and equipment near the tank. For this reason, a thorough understanding of the circumstances that can lead to a potentially problematic gas accumulation in sludge layers is needed. To respond to this need, the Deep Sludge Gas Release Event Program (DSGREP) was commissioned to examine gas release behavior in sludges.

Gas generation by self-radiolysis of tritiated waste materials

International Nuclear Information System (INIS)

Tadlock, W.E.; Abell, G.C.; Steinmeyer, R.H.

1980-01-01

Studies simulating the effect of self-radiolysis in disposal packages containing tritiated waste materials show hydrogen to be the dominant gas-phase product. Pressure buildup and gas composition over various tritiated octane and tritiated water samples are designed to give worst case results. One effect of tritium fixation agents is to reduce pressure buildup. The results show that development of explosive gas mixtures is unlikely and that maximum pressure buildup in typical Mound Facility waste packages can be expected to be <0.25 MPa

Study on removal technology for thorium in the waste gas-lamp mantle

International Nuclear Information System (INIS)

Shi Yucheng; Wang Chengbao; Zhang Ping; Xu Lingqi; Jiang Shangen

1999-01-01

The author describes thorium removal technology and its application in the handling of the waste gas-lamp mantle that produced during the production of gas-lamp process. After laboratory test, pilot test, trial run and engineering scale use, the thorium removal technology is mainly as follows: soak the waste gas-lamp mantle into the ceramic vat with the nitric acid solution twice and wash it with the tap water twice. The volume of the ceramic vat is 500 L and the concentration of the nitric acid solution is 2 mol/L. After handling, the thorium removal rate can reach 99.97% and the residual thorium will be less than 160 Bq/kg. The waste gas-lamp mantle can be buried under the ground or be handled in the other ways just as the harmless waste. The nitric acid solution, in which gas-lamp mantle has been soaked, should be extracted with TBP, then back extracted with diluted hydrochloric acid. After supplementing the thorium nitrate into the back extracted liquid, the liquid can be reused in the gas-lamp mantle production. The waste water from the handling process can be handled together with waste water from production process

Flammable gas production in Land 2 and Land 3/4 radioactive waste repositories

International Nuclear Information System (INIS)

1988-02-01

Geological, radiolytic and microbiological sources of gas are considered in relation to Land 2 and Land 3/4 type radioactive waste repositories. Geological sources are potentially the most troublesome and it is concluded that site investigation work should be designed to detect gas trap structures, reservoir lithologies or source rocks. Known source and reservoir lithologies should not be considered as suitable for the siting of waste repositories. Radiolytic and microbiological sources will depend on waste characteristics. A detailed review of the literature on radiolytic gas generation is presented and conclusions from this work indicate that water in waste and matrix should be kept to a minimum. Similarly, the level of radioactivity stored in each waste container should be kept to the minimum compatible with the storage design. Microbiological gas sources will be reduced by maintaining the cellulose content of the waste at a minimum. It is suggested that the removal of organics from the waste stream would be beneficial in terms of potential gas production. (author)

Air pollution from industrial waste gas emissions is associated with cancer incidences in Shanghai, China.

Science.gov (United States)

Cong, Xiaowei

2018-05-01

Outdoor air pollution may be associated with cancer risk at different sites. This study sought to investigate outdoor air pollution from waste gas emission effects on multiple cancer incidences in a retrospective population-based study in Shanghai, China. Trends in cancer incidence for males and females and trends in waste gas emissions for the total waste gas, industrial waste gas, other waste gas, SO 2 , and soot were investigated between 1983 and 2010 in Shanghai, China. Regression models after adjusting for confounding variables were constructed to estimate associations between waste gas emissions and multiple cancer incidences in the whole group and stratified by sex, Engel coefficient, life expectancy, and number of doctors per 10,000 populations to further explore whether changes of waste gas emissions were associated with multiple cancer incidences. More than 550,000 new cancer patients were enrolled and reviewed. Upward trends in multiple cancer incidences for males and females and in waste gas emissions were observed from 1983 to 2010 in Shanghai, China. Waste gas emissions came mainly from industrial waste gas. Waste gas emissions was significantly positively associated with cancer incidence of salivary gland, small intestine, colorectal, anus, gallbladder, thoracic organs, connective and soft tissue, prostate, kidney, bladder, thyroid, non-Hodgkin's lymphoma, lymphatic leukemia, myeloid leukemia, and other unspecified sites (all p emissions and the esophagus cancer incidence was observed (p emissions was associated with multiple cancer incidences.

Anesthetic action of volatile anesthetics by using Paramecium as a model.

Science.gov (United States)

Zhou, Miaomiao; Xia, Huimin; Xu, Younian; Xin, Naixing; Liu, Jiao; Zhang, Shihai

2012-06-01

Although empirically well understood in their clinical administration, volatile anesthetics are not yet well comprehended in their mechanism studies. A major conundrum emerging from these studies is that there is no validated model to assess the presumed candidate sites of the anesthetics. We undertook this study to test the hypothesis that the single-celled Paramecium could be anesthetized and served as a model organism in the study of anesthetics. We assessed the motion of Paramecium cells with Expert Vision system and the chemoresponse of Paramecium cells with T-maze assays in the presence of four different volatile anesthetics, including isoflurane, sevoflurane, enflurane and ether. Each of those volatiles was dissolved in buffers to give drug concentrations equal to 0.8, 1.0, and 1.2 EC50, respectively, in clinical practice. We could see that after application of volatile anesthetics, the swimming of the Paramecium cells was accelerated and then suppressed, or even stopped eventually, and the index of the chemoresponse of the Paramecium cells (denoted as I ( che )) was decreased. All of the above impacts were found in a concentration-dependent fashion. The biphasic effects of the clinical concentrations of volatile anesthetics on Paramecium simulated the situation of high species in anesthesia, and the inhibition of the chemoresponse also indicated anesthetized. In conclusion, the findings in our studies suggested that the single-celled Paramecium could be anesthetized with clinical concentrations of volatile anesthetics and therefore be utilized as a model organism to study the mechanisms of volatile anesthetics.

Comparing the greenhouse gas emissions from three alternative waste combustion concepts

International Nuclear Information System (INIS)

Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

2012-01-01

Highlights: ► Significant GHG reductions are possible by efficient WtE technologies. ► CHP and high power-to-heat ratio provide significant GHG savings. ► N 2 O and coal mine type are important in LCA GHG emissions of FBC co-combustion. ► Substituting coal and fuel oil by waste is beneficial in electricity and heat production. ► Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO 2 -eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

Manual on oil-gas industry waste utilization radioecological safety

International Nuclear Information System (INIS)

Kudryashev, V.A.; Lukashenko, S.N.; Tuleushev, A.Zh.; Marabaev, Zh.N.; Pasysaev, V.A.; Kayukov, P.G.; Kozhakhmetov, N.B.; Shevtsov, S.P.

2003-01-01

The development of a new document - 'Manual on radio-ecologically safe utilization of waste from oil-and-gas production' is carried out. This document regulates the whole cycle of environment protection measures at waste utilization for the named industry in Kazakhstan and is aimed on lowering the radiation risks and assurance of radioecological safety both at present and for the future. The document presents a set regulations necessary for radioactive wastes handling in the oil-gas industry. The normative document was agreed in both the Ministry of Health of the Republic of Kazakhstan (RK) and Ministry of Environment Protection of RK

Comparing the greenhouse gas emissions from three alternative waste combustion concepts.

Science.gov (United States)

Vainikka, Pasi; Tsupari, Eemeli; Sipilä, Kai; Hupa, Mikko

2012-03-01

Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO(2)-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved. Copyright © 2011 Elsevier Ltd. All rights reserved.

Waste gas could provide power for ships

Energy Technology Data Exchange (ETDEWEB)

1970-07-18

Dual-fuel engines are not new, but a version has been produced which, when used on ships carrying liquefied natural gas (LNG) could operate almost completely on waste gas. In its gas-operating mode, an engine can use the waste gas boiled off an LNG cargo. This wastage, normally allowed to escape to atmosphere, is about 0.25% of the cargo per day. Calculations have shown that this is enough to provide almost all the propulsion needs of a tanker under full cargo. This design is important in that it is suitable for the larger vessels now being required to carry LNG from N. Africa to North America, a journey where the costs of fuel are very considerable. Tests on the engine have indicated that power output is reduced to something like 80% of power under diesel fuel. However, additional advantages, such as cleaner engines with reduced maintenance costs, will help to tip the economic balance even further in favor of the dual purpose unit. This system also is applicable to stationary generating plant, again particularly on LNG tankage units where the same degree of gas boil-off applies.

Gas generation from radiolytic attack of TRU-contaminated hydrogenous waste

International Nuclear Information System (INIS)

Zerwekh, A.

1979-06-01

In 1970, the Waste Management and Transportation Division of the Atomic Energy Commission ordered a segregation of transuranic (TRU)-contaminated solid wastes. Those below a contamination level of 10 nCi/g could still be buried; those above had to be stored retrievably for 20 y. The possibility that alpha-radiolysis of hydrogenous materials might produce toxic, corrosive, and flammable gases in retrievably stored waste prompted an investigation of gas identities and generation rates in the laboratory and field. Typical waste mixtures were synthesized and contaminated for laboratory experiments, and drums of actual TRU-contaminated waste were instrumented for field testing. Several levels of contamination were studied, as well as pressure, temperature, and moisture effects. G (gas) values were determined for various waste matrices, and degradation products were examined

Radioactive gas waste processing device

International Nuclear Information System (INIS)

Soma, Koichi.

1996-01-01

The present invention concerns a radioactive gas waste processing device which extracts exhaust gases from a turbine condensator in a BWR type reactor and releases them after decaying radioactivity thereof during temporary storage. The turbine condensator is connected with an extracting ejector, a preheater, a recombiner for converting hydrogen gas into steams, an off gas condensator for removing water content, a flow rate control valve, a dehumidifier, a hold up device for removing radiation contaminated materials, a vacuum pump for sucking radiation decayed-off gases, a circulation water tank for final purification and an exhaustion cylinder by way of connection pipelines in this order. An exhaust gas circulation pipeline is disposed to circulate exhaust gases from an exhaust gas exit pipeline of the recycling water tank to an exhaust gas exit pipeline of the exhaust gas condensator, and a pressure control valve is disposed to the exhaust gas circulation pipeline. This enable to perform a system test for the dehumidification device under a test condition approximate to the load of the dehumidification device under actual operation state, and stabilize both of system flow rate and pressure. (T.M.)

Gas generation and migration analysis for TRU waste disposal system

International Nuclear Information System (INIS)

Ando, Kenichi; Noda, Masaru; Yamamoto, Mikihiko; Mihara, Morihiro

2005-09-01

In TRU waste disposal system, significant quantities of gases may be generated due to metal corrosion, radiolysis effect and microorganism activities. It is therefore recommended that the potential impact of gas generation and migration on TRU waste repository should be evaluated. In this study, gas generation rates were calculated in the repository and gas migration analysis in the disposal system were carried out using two phase flow model with results of gas generation rates. First, the time dependencies of gas generation rate in each TRU waste repositories were evaluated based on amounts of metal, organic matter and radioactivity. Next, the accumulation pressure of gases and expelled pore water volume nuclides in the repository were calculated by TOUGH2 code. After that, the results showed that the increase of gas pressure was the range of 1.3 to 1.4 MPa. In the repository with and without buffer, the rate of expelled pore water was 0.006 - 0.009 m 3 /y and 0.018 - 0.24m 3 /y, respectively. In addition, the radioactive gas migration through the repository and geosphere are evaluated. And re-saturation analysis is also performed to evaluate the initial condition of the system. (author)

Greenhouse gas accounting and waste management

DEFF Research Database (Denmark)

Gentil, Emmanuel; Christensen, Thomas Højlund; Aoustin, E.

2009-01-01

Accounting of emissions of greenhouse gas (GHG) is a major focus within waste management. This paper analyses and compares the four main types of GHG accounting in waste management including their special features and approaches: the national accounting, with reference to the Intergovernmental...... specifically, the clean development mechanism (CDM) methodology, introduced to support cost-effective reduction in GHG emissions. These types of GHG accounting, in principle, have a common starting point in technical data on GHG emissions from specific waste technologies and plants, but the limited...... Panel on Climate Change (IPCC), the corporate level, as part of the annual reporting on environmental issues and social responsibility, life-cycle assessment (LCA), as an environmental basis for assessing waste management systems and technologies, and finally, the carbon trading methodology, and more...

Control Decisions for Flammable Gas Hazards in Waste Transfer Systems

International Nuclear Information System (INIS)

KRIPPS, L.J.

2000-01-01

This report describes the control decisions for flammable gas hazards in waste transfer systems (i.e., waste transfer piping and waste transfer-associated structures) made at control decision meetings on November 30, 1999a and April 19, 2000, and their basis. These control decisions, and the analyses that support them, will be documented in an amendment to the Final Safety Analysis Report (FSAR) (CHG 2000a) and Technical Safety Requirements (TSR) (CHG 2000b) to close the Flammable Gas Unreviewed Safety Question (USQ) (Bacon 1996 and Wagoner 1996). Following the Contractor Tier I review of the FSAR and TSR amendment, it will be submitted to the US. Department of Energy (DOE), Office of River Protection (ORP) for review and approval. The control decision meeting on November 30, 1999 to address flammable gas hazards in waste transfer systems followed the control decision process and the criteria for control decisions described in Section 3.3.1.5 of the FSAR. The control decision meeting agenda, attendance list, and introductory and background presentations are included in Attachments 1 through 4. The control decision discussions on existing and other possible controls for flammable gas hazards in waste transfer systems and the basis for selecting or not selecting specific controls are summarized in this report

Dew point, internal gas pressure, and chemical composition of the gas within the free volume of DWPF canistered waste forms

International Nuclear Information System (INIS)

Harbour, J.R.; Herman, D.T.; Crump, S.; Miller, T.J.; McIntosh, J.

1996-01-01

The Defense Waste Processing Facility (DWPF) produced 55 canistered waste forms containing simulated waste glass during the four Waste Qualification campaigns of the DWPF Startup Test Program. Testing of the gas within the free volume of these canisters for dew point, internal gas pressure, and chemical composition was performed as part of a continuing effort to demonstrate compliance with the Waste Acceptance Product Specifications. Results are presented for six glass-filled canisters. The dew points within the canisters met the acceptance criterion of < 20 degrees C for all six canisters. Factors influencing the magnitude of the dew point are presented. The chemical composition of the free volume gas was indistinguishable from air for all six canisters. Hence, no foreign materials were present in the gas phase of these canisters. The internal gas pressures within the sealed canisters were < 1 atm at 25 degrees C for all six canisters which readily met the acceptance criterion of an internal gas pressure of less than 1.5 atm at 25 degrees C. These results provided the evidence required to demonstrate compliance with the Waste Acceptance Product Specifications

Improvement of anaerobic bio-hydrogen gas production from organic sludge waste

International Nuclear Information System (INIS)

Lee, S.; Lee, Y. H.

2009-01-01

Microbial hydrogen gas production from organic matters stands out as one of the most promising alternatives for sustainable green energy production. Based on the literature review, investigation of anaerobic bio-hydrogen gas production from organic sludge waste using a mixed culture has been very limited. The objective of this study was to assess the anaerobic bio-hydrogen gas production from organic sludge waste under various conditions. (Author)

Waste gas combustion in a Hanford radioactive waste tank

International Nuclear Information System (INIS)

Travis, J.R.; Fujita, R.K.; Spore, J.W.

1994-01-01

It has been observed that a high-level radioactive waste tank generates quantities of hydrogen, ammonia, nitrous oxide, and nitrogen that are potentially well within flammability limits. These gases are produced from chemical and nuclear decay reactions in a slurry of radioactive waste materials. Significant amounts of combustible and reactant gases accumulate in the waste over a 110- to 120-d period. The slurry becomes Taylor unstable owing to the buoyancy of the gases trapped in a matrix of sodium nitrate and nitrite salts. As the contents of the tank roll over, the generated waste gases rupture through the waste material surface, allowing the gases to be transported and mixed with air in the cover-gas space in the dome of the tank. An ignition source is postulated in the dome space where the waste gases combust in the presence of air resulting in pressure and temperature loadings on the double-walled waste tank. This analysis is conducted with hydrogen mixing studies HMS, a three-dimensional, time-dependent fluid dynamics code coupled with finite-rate chemical kinetics. The waste tank has a ventilation system designed to maintain a slight negative gage pressure during normal operation. We modeled the ventilation system with the transient reactor analysis code (TRAC), and we coupled these two best-estimate accident analysis computer codes to model the ventilation system response to pressures and temperatures generated by the hydrogen and ammonia combustion

A model of gas generation and transport within TRU [transuranic] waste drums

International Nuclear Information System (INIS)

Smith, F.G. III.

1987-01-01

Gas generation from the radiolytic decomposition of organic material contaminated with plutonium is modeled. Concentrations of gas throughout the waste drum are determined using a diffusional transport model. The model accurately reproduces experimentally measured gas concentrations. With polyethylene waste in unvented drums, the model predicts that hydrogen gas can accumulate to concentrations greater than 4 mole percent (lower flammable limit) with about 5 Ci of plutonium. Polyethylene provides a worst case for combustible waste material. If the drum liner is punctured and a carbon composite filter vent is installed in the drum lid, the plutonium loading can be increased to 240 Ci without generating flammable gas mixtures. 5 refs., 7 figs., 4 tabs

Gas distribution effects on waste properties: Viscosities of bubbly slurries

International Nuclear Information System (INIS)

Gauglitz, P.A.; Shah, R.R.; Davis, R.L.

1994-09-01

The retention and episodic release of flammable gases are critical safety concerns for double-shell tanks that contain waste slurries. The rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles. The presence of gas bubbles is expected to affect the rheology of the sludge, but essentially no literature data are available to assess the effect of bubbles. Accordingly, the objectives of this study are to develop models for the effect of gas bubbles on the viscosity of a particulate slurry, develop an experimental method (capillary rheometer), collect data on the viscosity of a bubbly slurry, and develop a theoretical basis for interpreting the experimental data from the capillary rheometer

Component design considerations for gas turbine HTGR waste-heat power plant

International Nuclear Information System (INIS)

McDonald, C.F.; Vrable, D.L.

1976-01-01

Component design considerations are described for the ammonia waste-heat power conversion system of a large helium gas-turbine nuclear power plant under development by General Atomic Company. Initial component design work was done for a reference plant with a 3000-MW(t) High-Temperature Gas-Cooled Reactor (HTGR), and this is discussed. Advanced designs now being evaluated include higher core outlet temperature, higher peak system pressures, improved loop configurations, and twin 4000-MW(t) reactor units. Presented are the design considerations of the major components (turbine, condenser, heat input exchanger, and pump) for a supercritical ammonia Rankine waste heat power plant. The combined cycle (nuclear gas turbine and waste-heated plant) has a projected net plant efficiency of over 50 percent. While specifically directed towards a nuclear closed-cycle helium gas-turbine power plant (GT-HTGR), it is postulated that the bottoming waste-heat cycle component design considerations presented could apply to other low-grade-temperature power conversion systems such as geothermal plants

78 FR 64905 - Carriage of Conditionally Permitted Shale Gas Extraction Waste Water in Bulk

Science.gov (United States)

2013-10-30

...-ZA31 Carriage of Conditionally Permitted Shale Gas Extraction Waste Water in Bulk AGENCY: Coast Guard... availability of a proposed policy letter concerning the carriage of shale gas extraction waste water in bulk... transport shale gas extraction waste water in bulk. The policy letter also defines the information the Coast...

Slurry growth, gas retention, and flammable gas generation by Hanford radioactive waste tanks: Synthetic waste studies, FY 1991

International Nuclear Information System (INIS)

Bryan, S.A.; Pederson, L.R.; Ryan, J.L.; Scheele, R.D.; Tingey, J.M.

1992-08-01

Of 177 high-level waste storage tanks on the Hanford Site, 23 have been placed on a safety watch list because they are suspected of producing flammable gases in flammable or explosive concentrate. One tankin particular, Tank 241-SY-101 (Tank 101-SY), has exhibited slow increases in waste volume followed by a rapid decrease accompanied by venting of large quantities of gases. The purpose of this study is to help determine the processes by which flammable gases are produced, retained, and eventually released from Tank 101-SY. Waste composition data for single- and double-shell waste tanks on the flammable gas watch listare critically reviewed. The results of laboratory studies using synthetic double-shell wastes are summarized, including physical and chemical properties of crusts that are formed, the stoichiometry and rate ofgas generation, and mechanisms responsible for formation of a floating crust

Radiolytic gas production from concrete containing Savannah River Plant waste

International Nuclear Information System (INIS)

Bibler, N.E.

1978-01-01

To determine the extent of gas production from radiolysis of concrete containing radioactive Savannah River Plant waste, samples of concrete and simulated waste were irradiated by 60 Co gamma rays and 244 Cm alpha particles. Gamma radiolysis simulated radiolysis by beta particles from fission products in the waste. Alpha radiolysis indicated the effect of alpha particles from transuranic isotopes in the waste. With gamma radiolysis, hydrogen was the only significant product; hydrogen reached a steady-state pressure that increased with increasing radiation intensity. Hydrogen was produced faster, and a higher steady-state pressure resulted when an organic set retarder was present. Oxygen that was sealed with the wastes was depleted. Gamma radiolysis also produced nitrous oxide gas when nitrate or nitrite was present in the concrete. With alpha radiolysis, hydrogen and oxygen were produced. Hydrogen did not reach a steady-state pressure at 137 Cs and 90 Sr), hydrogen will reach a steady-state pressure of 8 to 28 psi, and oxygen will be partially consumed. These predictions were confirmed by measurement of gas produced over a short time in a container of concrete and actual SRP waste. The tests with simulated waste also indicated that nitrous oxide may form, but because of the low nitrate or nitrite content of the waste, the maximum pressure of nitrous oxide after 300 years will be 238 Pu and 239 Pu will predominate; the hydrogen and oxygen pressures will increase to >200 psi

High-level waste vitrification off-gas cleanup technology

International Nuclear Information System (INIS)

Hanson, M.S.

1980-01-01

This brief overview is intended to be a basis for discussion of needs and problems existing in the off-gas clean-up technology. A variety of types of waste form and processes are being developed in the United States and abroad. A description of many of the processes can be found in the Technical Alternative Documents (TAD). Concurrently, off-gas processing systems are being developed with most of the processes. An extensive review of methodology as well as decontamination factors can be found in the literature. Since it is generally agreed that the most advanced solidification process is vitrification, discussion here centers about the off-gas problems related to vitrification. With a number of waste soldification facilities around the world in operation, it can be shown that present technology can satisfy the present requirement for off-gas control. However, a number of areas within the technology base show potential for improvement. Fundamental as well as verification studies are needed to obtain the improvements

In situ rheology and gas volume in Hanford double-shell waste tanks

International Nuclear Information System (INIS)

Stewart, C.W.; Alzheimer, J.M.; Brewster, M.E.; Chen, G.; Reid, H.C.; Shepard, C.L.; Terrones, G.; Mendoza, R.E.

1996-09-01

This report is a detailed characterization of gas retention and release in 6 Hanford DS waste tanks. The results came from the ball rheometer and void fraction instrument in (flammable gas watch list) tanks SY-101, SY-103, AW-101, AN-103, AN-104, and AN-105 are presented. Instrument operation and derivation of data reduction methods are presented. Gas retention and release information is summarized for each tank and includes tank fill history and instrumentation, waste configuration, gas release, void fraction distribution, gas volumes, rheology, and photographs of the waste column from extruded core samples. Potential peak burn pressure is computed as a function of gas release fraction to portray the 'hazard signature' of each tank. It is shown that two tanks remain well below the maximum allowable pressure, even if the entire gas content were released and ignited, and that none of the others present a hazard with their present gas release behavior

Probe into Environmental Kuznets Characteristics and Causes of Wastewater,Waste Gas, and Solid Wastes in Wuhan City

Institute of Scientific and Technical Information of China (English)

刘耀彬; 李仁东

2004-01-01

Environmental Kuznets characteristics and causes of waste water, waste gas, and solid wastes in Wuhan city was researched; By comparing the variation of "three wastes", i.e. waste water, waste gas, and solid wastes, the model between standardized per capita GDP and values of "three wastes" discharge was established and the causes were analyzed based on the theory of environmental economics. The results show that 1) the total amount is fluctuantly increasing, but the discharges of the three kinds are temporarily different, 2) the curve conforms to the three-power function, in which the curve descends from 1985 to 1994, and the curve preliminary shows the environmental Kuznets characteristics from 1995 to 2001, 3) the simulated calculation illustrates that the turning point of this environmental Kuznets curve would be over 25007.25 Yuan per caprta, and 4) the economic development, changing of industry structure, energy resource structure, and environmental policies are the main factors leading to the Environmental Kuznets Curve in Wuhan city.

Increased productivity through waste reduction effort in oil and gas company

Science.gov (United States)

Hidayati, J.; Silviana, NA; Matondang, RA

2018-02-01

National companies engaged in oil and gas activities in the upstream sector. In general, the on going operations include drilling, exploration, and production activities with the result being crude oil channelled for shipment. Production activities produce waste gas (flare) of 0.58 MMSCFD derived from 17.05% of natural gas produced. Gas flares are residual gases that have been burning through flare stacks to avoid toxic gases such as H2S and CO that are harmful to human health and the environment. Therefore, appropriate environmental management is needed; one of them is by doing waste reduction business. Through this approach, it is expected that waste reduction efforts can affect the improvement of environmental conditions while increasing the productivity of the company. In this research begins by identifying the existence of problems on the company related to the amount of waste that is excessive and potentially to be reduced. Alternative improvements are then formulated and selected by their feasibility to be implemented through financial analysis, and the estimation of alternative contributions to the level of productivity. The result of this research is an alternative solution to solve the problem of the company by doing technological based engineering by reusing gas flare into fuel for incinerator machine. This alternative contributes to the increased productivity of material use by 23.32%, humans 83.8%, capital 10.13 %, and waste decreased by 0.11%.

Gas generation from low-level radioactive waste: Concerns for disposal

International Nuclear Information System (INIS)

Siskind, B.

1992-01-01

The Advisory Committee on Nuclear Waste (ACNW) has urged the Nuclear Regulatory Commission (NRC) to reexamine the topic of hydrogen gas generation from low-level radioactive waste (LLW) in closed spaces to ensure that the slow buildup of hydrogen from water-bearing wastes in sealed containers does not become a problem for long-term safe disposal. Brookhaven National Laboratory (BNL) has prepared a report, summarized in this paper, for the NRC to respond to these concerns. The paper discusses the range of values for G(H 2 ) reported for materials of relevance to LLW disposal; most of these values are in the range of 0.1 to 0.6. Most studies of radiolytic hydrogen generation indicate a leveling off of pressurization, probably because of chemical kinetics involving, in many cases, the radiolysis of water within the waste. Even if no leveling off occurs, realistic gas leakage rates (indicating poor closure by gaskets on drums and liners) will result in adequate relief of pressure for radiolytic gas generation from the majority of commercial sector LLW packages. Biodegradative gas generation, however, could pose a pressurization hazard even at realistic gas leakage rates. Recommendations include passive vents on LLW containers (as already specified for high integrity containers) and upper limits to the G values and/or the specific activity of the LLW

Day-surgery patients anesthetized with propofol have less postoperative pain than those anesthetized with sevoflurane.

LENUS (Irish Health Repository)

Tan, Terry

2012-02-01

BACKGROUND: There have been recent studies suggesting that patients anesthetized with propofol have less postoperative pain compared with patients anesthetized with volatile anesthetics. METHODS: In this randomized, double-blind study, 80 patients undergoing day-case diagnostic laparoscopic gynecological surgery were either anesthetized with IV propofol or sevoflurane. The primary outcome measured was pain on a visual analog scale. RESULTS: Patients anesthetized with propofol had less pain compared with patients anesthetized with sevoflurane (P = 0.01). There was no difference in any of the other measured clinical outcomes. CONCLUSIONS: The patients anesthetized with propofol appeared to have less pain than patients anesthetized with sevoflurane.

Toluene : biological waste-gas treatment, toxicity and microbial adaptation

NARCIS (Netherlands)

Weber, F.J.

1995-01-01

Due to the increasing stringent legislation concerning the emission of volatile organic compounds, there is nowadays a growing interest to apply biological waste-gas treatment techniques for the removal of higher concentrations of specific contaminants from waste gases. Fluctuations in the

Flammable gas tank waste level reconciliation tank 241-SX-105

International Nuclear Information System (INIS)

Brevick, C.H.; Gaddie, L.A.

1997-01-01

Fluor Daniel Northwest was authorized to address flammable gas issues by reconciling the unexplained surface level increases in Tank 241-SX-105 (SX-105, typical). The trapped gas evaluation document states that Tank SX-105 exceeds the 25% of the lower flammable limit criterion, based on a surface level rise evaluation. The Waste Storage Tank Status and Leak Detection Criteria document, commonly referred to as the Welty Report is the basis for this letter report. The Welty Report is also a part of the trapped gas evaluation document criteria. The Welty Report contains various tank information, including: physical information, status, levels, and dry wells. The unexplained waste level rises were attributed to the production and retention of gas in the column of waste corresponding to the unaccounted for surface level rise. From 1973 through 1980, the Welty Report tracked Tank SX-105 transfers and reported a net cumulative change of 20.75 in. This surface level increase is from an unknown source or is unaccounted for. Duke Engineering and Services Hanford and Lockheed Martin Hanford Corporation are interested in determining the validity of unexplained surface level changes reported in the Welty Report based upon other corroborative sources of data. The purpose of this letter report is to assemble detailed surface level and waste addition data from daily tank records, logbooks, and other corroborative data that indicate surface levels, and to reconcile the cumulative unaccounted for surface level changes as shown in the Welty Report from 1973 through 1980. Tank SX-105 initially received waste from REDOX starting the second quarter of 1955. After June 1975, the tank primarily received processed waste (slurry) from the 242-S Evaporator/Crystallizer and transferred supernate waste to Tanks S-102 and SX-102. The Welty Report shows a cumulative change of 20.75 in. from June 1973 through December 1980

Titration calorimetry of anesthetic-protein interaction: negative enthalpy of binding and anesthetic potency.

Science.gov (United States)

Ueda, I; Yamanaka, M

1997-04-01

Anesthetic potency increases at lower temperatures. In contrast, the transfer enthalpy of volatile anesthetics from water to macromolecules is usually positive. The transfer decreases at lower temperature. It was proposed that a few selective proteins bind volatile anesthetics with negative delta H, and these proteins are involved in signal transduction. There has been no report on direct estimation of binding delta H of anesthetics to proteins. This study used isothermal titration calorimetry to analyze chloroform binding to bovine serum albumin. The calorimetrically measured delta H cal was -10.37 kJ.mol-1. Thus the negative delta H of anesthetic binding is not limited to signal transduction proteins. The binding was saturable following Fermi-Dirac statistics and is characterized by the Langmuir adsorption isotherms, which is interfacial. The high-affinity association constant, K, was 2150 +/- 132 M-1 (KD = 0.47 mM) with the maximum binding number, Bmax = 3.7 +/- 0.2. The low-affinity K was 189 +/- 3.8 M-1 (KD = 5.29 mM), with a Bmax of 13.2 +/- 0.3. Anesthetic potency is a function of the activity of anesthetic molecules, not the concentration. Because the sign of delta H determines the temperature dependence of distribution of anesthetic molecules, it is irrelevant to the temperature dependence of anesthetic potency.

Effectiveness of the Vertical Gas Ventilation Pipes for Promoting Waste Stabilization in Post-Closure Phase

Directory of Open Access Journals (Sweden)

Yasumasa Tojo

2015-06-01

Full Text Available To make inside of the municipal solid waste (MSW landfill aerobic as much as possible is thought to be preferable for promoting waste stabilization, reducing pollutant's load in leachate, minimizing greenhouse gas emission and shortening post-closure-care period. In Japan, installation of semi-aerobic landfill structure has widely spread in order to promote waste stabilization in MSW landfill from 1980s. In semi-aerobic landfill structure, outlet of main leachate collection pipe is opened to atmosphere. Heat generated by aerobic degradation of waste causes natural convection and natural aeration arises from the outlet of leachate collection pipe to the gas vents. It is so-called stack effect. This air flow is thought to be effective for purifying leachate flowing through drainage layer and leachate collection pipes. And it is also thought to be contributing to expanding aerobic region in waste layer in landfill. Recently, measures attempting the promotion of waste stabilization are taken at several landfills at where stabilization of waste delays, in which many vertical gas vents are newly installed and close structure to semi-aerobic landfill is created. However, in many cases, these gas vents are not connected to leachate collection pipes. Many vertical gas vents are just installed without scientific proof regarding whether they can contribute for waste stabilization. In this study, how such installation of gas vents is effective for waste stabilization and aerobization of waste layer was discussed by numerical analysis. In numerical analysis, heat transfer, gas movement by pressure, gas diffusion, biological degradation of organic matter, and heat generation by biodegradation were taken into account. Simulations were carried out by using the general purpose simulator of finite element method. Three types of landfill structure were assumed. As the results, the following information were obtained. In dig-down type landfill, installation of gas

Optimisation of environmental gas cleaning routes for solid wastes cogeneration systems. Part II - Analysis of waste incineration combined gas/steam cycle

International Nuclear Information System (INIS)

Holanda, Marcelo R.; Perrella Balestieri, Jose A.

2008-01-01

In the first paper of this paper (Part I), conditions were presented for the gas cleaning technological route for environomic optimisation of a cogeneration system based in a thermal cycle with municipal solid waste incineration. In this second part, an environomic analysis is presented of a cogeneration system comprising a combined cycle composed of a gas cycle burning natural gas with a heat recovery steam generator with no supplementary burning and a steam cycle burning municipal solid wastes (MSW) to which will be added a pure back pressure steam turbine (another one) of pure condensation. This analysis aims to select, concerning some scenarios, the best atmospheric pollutant emission control routes (rc) according to the investment cost minimisation, operation and social damage criteria. In this study, a comparison is also performed with the results obtained in the Case Study presented in Part I

Radiolytic gas generation in plutonium contaminated waste materials

International Nuclear Information System (INIS)

Kazanjian, A.R.

1976-01-01

Many plutonium contaminated waste materials decompose into gaseous products because of exposure to alpha radiation. The gases generated (usually hydrogen) over long-storage periods may create hazardous conditions. To determine the extent of such hazards, knowing the gas generation yields is necessary. These yields were measured by contacting some common Rocky Flats Plant waste materials with plutonium and monitoring the enclosed atmospheres for extensive periods of time. The materials were Plexiglas, polyvinyl chloride, glove-box gloves, machining oil, carbon tetrachloride, chlorothene VG solvent, Kimwipes (dry and wet), polyethylene, Dowex-1 resin, and surgeon's gloves. Both 239 Pu oxide and 238 Pu oxide were used as radiation sources. The gas analyses were made by mass spectrometry and the results obtained were the total gas generation, the hydrogen generation, the oxygen consumption rate, and the gas composition over the entire storage period. Hydrogen was the major gas produced in most of the materials. The total gas yields varied from 0.71 to 16 cm 3 (standard temperature pressure) per day per curie of plutonium. The oxygen consumption rates varied from 0.0088 to 0.070 millimoles per day per gram of plutonium oxide-239 and from 0.0014 to 0.0051 millimoles per day per milligram 238 Pu

Production and use of waste gas. Situation in Flanders.; Winnen en benutten van stortgas. Situatie in Vlaanderen.

Energy Technology Data Exchange (ETDEWEB)

Maes, G.; Beckers, H.

1997-08-01

Waste gas is an energy rich gas that origins by the anaerobic degradation of organic material, an d mainly consists of methane and carbon dioxide. To make an estimate of the amount of gas that comes free in function of time at a certain landfill , the multifasemodel can be used. This model is based on a first order reaction, by which is supposed that the speed of the degradation process is proportional to the amount of organic material still present in the landfill. Furthermore the model takes the different fractions of organic material which each have a different degradation speed into account. The model assumes that the waste gas production starts 1 year after dumping and immediately is optimal. From then on the waste gas production decreases exponential. In total about 9 million cubic meter waste gas per year is used in Flanders, which is less than 10% of the total amount of waste gas that comes free. If all waste gas would be extracted and used, about 78 million cubic meters natural gas would be saved at the moment. The amount of projects for application will grow in the future. Especially because of the stimulating measures for use of waste gas. So a reduced environmental tax must be paid in case of use of waste gas and 1 BEF/kWh is paid if electricity is produced with waste gas. In a number of our neighboring countries, waste gas is extracted and used on a large scale.

Gas production in anaerobic dark-fermentation processes from agriculture solid waste

Science.gov (United States)

Sriwuryandari, L.; Priantoro, E. A.; Sintawardani, N.

2017-03-01

Approximately, Bandung produces agricultural solid waste of 1549 ton/day. This wastes consist of wet-organic matter and can be used for bio-gas production. The research aimed to apply the available agricultural solid waste for bio-hydrogen. Biogas production was done by a serial of batches anaerobic fermentation using mix-culture bacteria as the active microorganism. Fermentation was carried out inside a 30 L bioreactor at room temperature. The analyzed parameters were of pH, total gas, temperature, and COD. Result showed that from 3 kg/day of organic wastes, various total gases of O2, CH4, H2, CO2, and CnHn,O2 was produced.

Exergy analysis of waste emissions from gas flaring

Directory of Open Access Journals (Sweden)

Olawale Saheed ISMAIL

2016-07-01

Full Text Available Gas flaring produces a stream of waste gases at high temperature and pressure which contains carbon monoxide, Hydrogen Sulphide etc. The resultant effect of which is detrimental to our planet and, consequently, to the life of both the living and the non-living things. It’s well known that gas flaring contributes in no small measure to the global warming. Exergy analysis is applied in this work to analyze waste emissions from gas flaring so as to have a model through which impact of gas flaring can be measured. The study considers both the thermo-mechanical exergy and the chemical exergy of these gases. Relevant data on gas flaring activities in the Niger-Delta region of Nigeria between the periods of fifteen (15 years was obtained from the Nigerian National Petroleum Corporation (NNPC. A computer program (Exergy Calculator was developed based on the equations generated in the Model. Exergy associated with gas flaring activities in Nigeria between the periods of 1998 through 2012 was calculated. The results show that 1 mscf (in thousand cubic feet of flared gases generate 0.000041 MWh of energy leading to a value of 440158.607 MWh of energy for the period under review.The analysis provides important conclusions and recommendations for improving oil platforms operationsin in order to safeguard the environment, health of the populace, and maximize recovered exergy from gas flaring.

Gas Generation in Radioactive Wastes - MAGGAS Predictive Life Cycle Model

International Nuclear Information System (INIS)

Streatfield, R.E.; Hebditch, D.J.; Swift, B.T.; Hoch, A.R.; Constable, M.

2006-01-01

Gases may form from radioactive waste in quantities posing different potential hazards throughout the waste package life cycle. The latter includes surface storage, transport, placing in an operating repository, storage in the repository prior to backfill, closure and the post-closure stage. Potentially hazardous situations involving gas include fire, flood, dropped packages, blocked package vents and disruption to a sealed repository. The MAGGAS (Magnox Gas generation) model was developed to assess gas formation for safety assessments during all stages of the waste package life cycle. This is a requirement of the U.K. regulatory authorities and Nirex and progress in this context is discussed. The processes represented in the model include: Corrosion, microbial degradation, radiolysis, solid-state diffusion, chemico-physical degradation and pressurisation. The calculation was split into three time periods. First the 'aerobic phase' is used to model the periods of surface storage, transport and repository operations including storage in the repository prior to backfill. The second and third periods were designated 'anaerobic phase 1' and 'anaerobic phase 2' and used to model the waste packages in the post-closure phase of the repository. The various significant gas production processes are modeled in each phase. MAGGAS (currently Version 8) is mounted on an Excel spreadsheet for ease of use and speed, has 22 worksheets and is operated routinely for assessing waste packages (e.g. for ventilation of stores and pressurisation of containers). Ten operational and decommissioning generic nuclear power station waste streams were defined as initial inputs, which included ion exchange materials, sludges and concentrates, fuel element debris, graphite debris, activated components, contaminated items, desiccants and catalysts. (authors)

Problems of comprehensive use of waste hydrogen-containing gas in petrochemistry

Energy Technology Data Exchange (ETDEWEB)

Kulikov, V M; Grabovskiy, O G; Yevplanov, A I

1979-01-01

At enterprises of the Ministry of the Petrochemical Industry, gas wastes, containing 60-70% CH/sub 4/ and 25-30% H/sub 2/, are practically completely used as boiler and furnace fuel. The situation is different with gases with a high H/sub 2/ content. Gases containing 70-90% H/sub 2/ are not used, and are emitted into the atmosphere. The gases are not detoxified by burning in torches, and the air basin is polluted by organic compounds contained in these gases that are harmful to people's health. Emitting combustible gases into the atmosphere is the result of fears of burning gases with a high H/sub 2/ content in burners designed to burn gases at a slower flame propagation speed, as well as a low gas pressure and their uneven exit. At the Kuybyshev synthetic alcohol plant, waste gases of the following composition (rounded) are formed: H2, 76; CH4, 8; C2H4, 7; C3H8, 1; CO2, 8%. The gas also contains fractions of a percent of ethane, propane, butylene and butadiene. The lowest combustion heat of 1 cubic meter of gas under normal conditions is 3875 kcal. The gas pressure is 0.2 kg-force/square cm. About 1500 cubic meters of gas form per hour. A hearth fantail burner developed by the Kuybyshev Polytechnical Institute is suggested for burning waste gas. Using waste gases in the petrochemical industry will enable a savings of less than or equal to 60,000 tons of equivalent fuel per year.

Anesthetic drug wastage in the operation room: A cause for concern

Directory of Open Access Journals (Sweden)

Kapil Chaudhary

2012-01-01

Full Text Available Context: The cost of anesthetic technique has three main components, i.e., disposable supplies, equipments, and anesthetic drugs. Drug budgets are an easily identifiable area for short-term savings. Aim: To assess and estimate the amount of anesthetic drug wastage in the general surgical operation room. Also, to analyze the financial implications to the hospital due to drug wastage and suggest appropriate steps to prevent or minimize this wastage. Settings and Design: A prospective observational study conducted in the general surgical operation room of a tertiary care hospital. Materials and Methods: Drug wastage was considered as the amount of drug left unutilized in the syringes/vials after completion of a case and any ampoule or vial broken while loading. An estimation of the cost of wasted drug was made. Results: Maximal wastage was associated with adrenaline and lignocaine (100% and 93.63%, respectively. The drugs which accounted for maximum wastage due to not being used after loading into a syringe were adrenaline (95.24%, succinylcholine (92.63%, lignocaine (92.51%, mephentermine (83.80%, and atropine (81.82%. The cost of wasted drugs for the study duration was 46.57% (Rs. 16,044.01 of the total cost of drugs issued/loaded (Rs. 34,449.44. Of this, the cost of wastage of propofol was maximum being 56.27% (Rs. 9028.16 of the total wastage cost, followed by rocuronium 17.80% (Rs. 2856, vecuronium 5.23% (Rs. 840, and neostigmine 4.12% (Rs. 661.50. Conclusions: Drug wastage and the ensuing financial loss can be significant during the anesthetic management of surgical cases. Propofol, rocuronium, vecuronium, and neostigmine are the drugs which contribute maximally to the total wastage cost. Judicious use of these and other drugs and appropriate prudent measures as suggested can effectively decrease this cost.

Targets Involved in Cardioprotection by the Non-Anesthetic Noble Gas Helium

NARCIS (Netherlands)

Weber, Nina C.; Smit, Kirsten F.; Hollmann, Markus W.; Preckel, Benedikt

2015-01-01

Research data from the past decade indicate that noble gases like xenon and helium exert profound cardioprotection when applied before, during or after organ ischemia. Of all noble gases, especially helium, has gained interest in the past years because it does not have an anesthetic "side effect"

Waste tank ventilation rates measured with a tracer gas method

International Nuclear Information System (INIS)

Huckaby, J.L.; Evans, J.C.; Sklarew, D.S.; Mitroshkov, A.V.

1998-08-01

Passive ventilation with the atmosphere is used to prevent accumulation of waste gases and vapors in the headspaces of 132 of the 177 high-level radioactive waste Tanks at the Hanford Site in Southeastern Washington State. Measurements of the passive ventilation rates are needed for the resolution of two key safety issues associated with the rates of flammable gas production and accumulation and the rates at which organic salt-nitrate salt mixtures dry out. Direct measurement of passive ventilation rates using mass flow meters is not feasible because ventilation occurs va multiple pathways to the atmosphere (i.e., via the filtered breather riser and unsealed tank risers and pits), as well as via underground connections to other tanks, junction boxes, and inactive ventilation systems. The tracer gas method discussed in this report provides a direct measurement of the rate at which gases are removed by ventilation and an indirect measurement of the ventilation rate. The tracer gas behaves as a surrogate of the waste-generated gases, but it is only diminished via ventilation, whereas the waste gases are continuously released by the waste and may be subject to depletion mechanisms other than ventilation. The fiscal year 1998 tracer studies provide new evidence that significant exchange of air occurs between tanks via the underground cascade pipes. Most of the single-shell waste tanks are connected via 7.6-cm diameter cascade pipes to one or two adjacent tanks. Tracer gas studies of the Tank U-102/U-103 system indicated that the ventilation occurring via the cascade line could be a significant fraction of the total ventilation. In this two-tank cascade, air evidently flowed from Tank U-103 to Tank U-102 for a time and then was observed to flow from Tank U-102 to Tank U-103

Influence of mechanical-biological waste pre-treatment methods on the gas formation in landfills

International Nuclear Information System (INIS)

Bockreis, A.; Steinberg, I.

2005-01-01

In order to minimise emissions and environmental impacts, only pre-treated waste should be disposed of. For the last six years, a series of continuous experiments has been conducted at the Institute WAR, TU Darmstadt, in order to determine the emissions from pre-treated waste. Different kinds of pre-treated waste were incubated in several reactors and various data, including production and composition of the gas and the leachate, were collected. In this paper, the interim results of gas production and the gas composition from different types of waste after a running time of six years are presented and discussed

Advanced Off-Gas Control System Design For Radioactive And Mixed Waste Treatment

International Nuclear Information System (INIS)

Nick Soelberg

2005-01-01

Treatment of radioactive and mixed wastes is often required to destroy or immobilize hazardous constituents, reduce waste volume, and convert the waste to a form suitable for final disposal. These kinds of treatments usually evolve off-gas. Air emission regulations have become increasingly stringent in recent years. Mixed waste thermal treatment in the United States is now generally regulated under the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. These standards impose unprecedented requirements for operation, monitoring and control, and emissions control. Off-gas control technologies and system designs that were satisfactorily proven in mixed waste operation prior to the implementation of new regulatory standards are in some cases no longer suitable in new mixed waste treatment system designs. Some mixed waste treatment facilities have been shut down rather than have excessively restrictive feed rate limits or facility upgrades to comply with the new standards. New mixed waste treatment facilities in the U. S. are being designed to operate in compliance with the HWC MACT standards. Activities have been underway for the past 10 years at the INL and elsewhere to identify, develop, demonstrate, and design technologies for enabling HWC MACT compliance for mixed waste treatment facilities. Some specific off-gas control technologies and system designs have been identified and tested to show that even the stringent HWC MACT standards can be met, while minimizing treatment facility size and cost

Toluene removal in a biofilm reactor for waste gas treatment

DEFF Research Database (Denmark)

Pedersen, A.R.; Arvin, E.

1997-01-01

A lab-scale trickling filter for treatment of toluene-containing waste gas was investigated. The filter performance was investigated for various loads of toluene. Two levels of the gas flow were examined, 322 m d(-1) and 707 m d(-1). The gas inlet concentrations were varied in the range from 0...

Greenhouse gas emissions from solid waste in Beijing: The rising trend and the mitigation effects by management improvements.

Science.gov (United States)

Yu, Yongqiang; Zhang, Wen

2016-04-01

Disposal of solid waste poses great challenges to city managements. Changes in solid waste composition and disposal methods, along with urbanisation, can certainly affect greenhouse gas emissions from municipal solid waste. In this study, we analysed the changes in the generation, composition and management of municipal solid waste in Beijing. The changes of greenhouse gas emissions from municipal solid waste management were thereafter calculated. The impacts of municipal solid waste management improvements on greenhouse gas emissions and the mitigation effects of treatment techniques of greenhouse gas were also analysed. Municipal solid waste generation in Beijing has increased, and food waste has constituted the most substantial component of municipal solid waste over the past decade. Since the first half of 1950s, greenhouse gas emission has increased from 6 CO2-eq Gg y(-1)to approximately 200 CO2-eq Gg y(-1)in the early 1990s and 2145 CO2-eq Gg y(-1)in 2013. Landfill gas flaring, landfill gas utilisation and energy recovery in incineration are three techniques of the after-emission treatments in municipal solid waste management. The scenario analysis showed that three techniques might reduce greenhouse gas emissions by 22.7%, 4.5% and 9.8%, respectively. In the future, if waste disposal can achieve a ratio of 4:3:3 by landfill, composting and incineration with the proposed after-emission treatments, as stipulated by the Beijing Municipal Waste Management Act, greenhouse gas emissions from municipal solid waste will decrease by 41%. © The Author(s) 2016.

Gas retention and release behavior in Hanford single-shell waste tanks

International Nuclear Information System (INIS)

Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

1996-12-01

This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large (∼100 m 3 ) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given

ACCURACY OF NONINVASIVE ANESTHETIC MONITORING IN THE ANESTHETIZED GIRAFFE (GIRAFFA CAMELOPARDALIS)

DEFF Research Database (Denmark)

Bertelsen, Mads F; Grøndahl, Carsten; Stegmann, George F

2017-01-01

This study evaluated the accuracy of pulse oximetry, capnography, and oscillometric blood pressure during general anesthesia in giraffes (Giraffa camelopardalis). Thirty-two giraffes anesthetized for physiologic experiments were instrumented with a pulse oximeter transmittance probe positioned...... on the tongue and a capnograph sampling line placed at the oral end of the endotracheal tube. A human size 10 blood pressure cuff was placed around the base of the tail, and an indwelling arterial catheter in the auricular artery continuously measured blood pressure. Giraffes were intermittently ventilated...... using a Hudson demand valve throughout the procedures. Arterial blood for blood gas analysis was collected at multiple time points. Relationships between oxygen saturation as determined by pulse oximetry and arterial oxygen saturation, between arterial carbon dioxide partial pressure and end...

Optimization of methane gas recovery from waste material and possibilities for its utilization

Energy Technology Data Exchange (ETDEWEB)

Shim, K C

1981-01-01

Sewer gas (biogas) can be generated from anaerobic decomposition of different waste substances, e.g. from sludge obtained in sewage works, from household refuse and from agricultural waste. In order to run a sewage works economically the managers of the plants are now obliged to show more interest in the maximum usage of this gas. Even though in most of the municipal waste water treatment plants in the Federal Republic of Germany the digesters are available, one quarter of the annual gas production remains unused. In view of the so-called 'energy crisis', it seems foolish to burn off sewer gas, a valuable source of energy and one, moreover, produced at high cost. Laboratory tests were carried out with agricultural wastes and with sludge and household refuse to analyse the sludge digestion process and determine the optimum conditions required by the process. Finally, the situation in Korea, where there are 30,000 biogas plants, is summarized. (Refs. 5).

Comparison of waste anesthetic gases in operating rooms with or without an scavenging system in a Brazilian University Hospital

Directory of Open Access Journals (Sweden)

Leandro Gobbo Braz

2017-09-01

Full Text Available Background and objectives: Occupational exposure to waste anesthetic gases in operating room without active scavenging system has been associated with adverse health effects. Thus, this study aimed to compare the trace concentrations of the inhalational anesthetics isoflurane and sevoflurane in operating room with and without central scavenging system. Method: Waste concentrations of isoflurane and sevoflurane were measured by infrared analyzer at different locations (near the respiratory area of the assistant nurse and anesthesiologist and near the anesthesia station and at two times (30 and 120 min after the start of surgery in both operating room types. Results: All isoflurane and sevoflurane concentrations in unscavenged operating room were higher than the US recommended limit (2 parts per million, regardless of the location and time evaluated. In scavenged operating room, the average concentrations of isoflurane were within the limit of exposure, except for the measurements near the anesthesia station, regardless of the measurement times. For sevoflurane, concentrations exceeded the limit value at all measurement locations and at both times. Conclusions: The exposure to both anesthetics exceeded the international limit in unscavenged operating room. In scavenged operating room, the concentrations of sevoflurane, and to a lesser extent those of isoflurane, exceeded the recommended limit value. Thus, the operating room scavenging system analyzed in the present study decreased the anesthetic concentrations, although not to the internationally recommended values. Resumo: Justificativa e objetivos: A exposição ocupacional aos resíduos de gases anestésicos em salas de operação (SO sem sistema ativo de exaustão tem sido associada a efeitos adversos à saúde. Assim, o objetivo do estudo foi comparar os resíduos dos anestésicos inalatórios isoflurano e sevoflurano em SO com e sem sistema de exaustão. Método: Concentrações residuais

Biodigestor for organic waste gas; Biodigestor para o gas do lixo organico

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Carla Miranda; Fernandes, Carla Barbosa; Souza, Aline Vieira da Silva e; Melo, Cibelly Caroliny Santos; Sales, Jefferson Santos; Frade, Marcelo Lorenzo; Machado, Marcus Vinicius; Frade, Matheus Costa; Gomes, Natashua Lauar; Costa, Pedro Henrique de Andrade; Moraes, Rodrigo de Almeida; Estrella, Thales Goncalves; Lima, Miriam Cristina Pontello Barbosa [Centro Universitario de Belo Horizonte (UniBH), MG (Brazil)], e-mails: carlam.ferreira@yahoo.com.br, miriam.pontello@gmail.com

2011-07-01

This article to present an alternative reuse os the gas produced by garbage, through the construction of a digester, with a view to preserving the environment through renewable energy. The energy produced by this system is obtained from the decomposition of organic waste is biogas, made up of gases such as methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). This experiment verifies the possibility of using methane gas as an alternative to the operation of a domestic stove. (author)

Design and operation of off-gas cleaning systems at high level liquid waste conditioning facilities

International Nuclear Information System (INIS)

1988-01-01

The immobilization of high level liquid wastes from the reprocessing of irradiated nuclear fuels is of great interest and serious efforts are being undertaken to find a satisfactory technical solution. Volatilization of fission product elements during immobilization poses the potential for the release of radioactive substances to the environment and necessitates effective off-gas cleaning systems. This report describes typical off-gas cleaning systems used in the most advanced high level liquid waste immobilization plants and considers most of the equipment and components which can be used for the efficient retention of the aerosols and volatile contaminants. In the case of a nuclear facility consisting of several different facilities, release limits are generally prescribed for the nuclear facility as a whole. Since high level liquid waste conditioning (calcination, vitrification, etc.) facilities are usually located at fuel reprocessing sites (where the majority of the high level liquid wastes originates), the off-gas cleaning system should be designed so that the airborne radioactivity discharge of the whole site, including the emission of the waste conditioning facility, can be kept below the permitted limits. This report deals with the sources and composition of different kinds of high level liquid wastes and describes briefly the main high level liquid waste solidification processes examining the sources and characteristics of the off-gas contaminants to be retained by the off-gas cleaning system. The equipment and components of typical off-gas systems used in the most advanced (large pilot or industrial scale) high level liquid waste solidification plants are described. Safety considerations for the design and safe operation of the off-gas systems are discussed. 60 refs, 31 figs, 17 tabs

Greenhouse gas accounting and waste management.

Science.gov (United States)

Gentil, Emmanuel; Christensen, Thomas H; Aoustin, Emmanuelle

2009-11-01

Accounting of emissions of greenhouse gas (GHG) is a major focus within waste management. This paper analyses and compares the four main types of GHG accounting in waste management including their special features and approaches: the national accounting, with reference to the Intergovernmental Panel on Climate Change (IPCC), the corporate level, as part of the annual reporting on environmental issues and social responsibility, life-cycle assessment (LCA), as an environmental basis for assessing waste management systems and technologies, and finally, the carbon trading methodology, and more specifically, the clean development mechanism (CDM) methodology, introduced to support cost-effective reduction in GHG emissions. These types of GHG accounting, in principle, have a common starting point in technical data on GHG emissions from specific waste technologies and plants, but the limited availability of data and, moreover, the different scopes of the accounting lead to many ways of quantifying emissions and producing the accounts. The importance of transparency in GHG accounting is emphasised regarding waste type, waste composition, time period considered, GHGs included, global warming potential (GWP) assigned to the GHGs, counting of biogenic carbon dioxide, choice of system boundaries, interactions with the energy system, and generic emissions factors. In order to enhance transparency and consistency, a format called the upstream-operating-downstream framework (UOD) is proposed for reporting basic technology-related data regarding GHG issues including a clear distinction between direct emissions from waste management technologies, indirect upstream (use of energy and materials) and indirect downstream (production of energy, delivery of secondary materials) activities.

Treatment of off-gas evolved from thermal decomposition of sludge waste

International Nuclear Information System (INIS)

Doo-Seong Hwang; Yun-Dong Choi; Gyeong-Hwan Jeong; Jei-Kwon Moon

2013-01-01

Korea Atomic Energy Research Institute (KAERI) started a decommissioning program of a uranium conversion plant. The treatment of the sludge waste, which was generated during the operation of the plant, is one of the most important tasks in the decommissioning program of the plant. The major compounds of sludge waste are nitrate salts and uranium. The sludge waste is denitrated by thermal decomposition. The treatment of off-gas evolved from the thermal decomposition of nitrate salts in the sludge waste is investigated. The nitrate salts in the sludge were decomposed in two steps: the first decomposition is due to the ammonium nitrate, and the second is due to the sodium and calcium nitrate and calcium carbonate. The components of off-gas from the decomposition of ammonium nitrate at low temperature are NH 3 , N 2 O, NO 2 , and NO. In addition, the components from the decomposition of sodium and calcium nitrate at high temperature are NO 2 and NO. Off-gas from the thermal decomposition is treated by the catalytic oxidation of ammonia and selective catalytic reduction (SCR). Ammonia is converted into nitrogen oxides through the oxidation catalyst and all nitrogen oxides are removed by SCR treatment besides nitrous oxide, which is greenhouse gas. An additional process is needed to remove nitrous oxide, and the feeding rate of ammonia in SCR should be controlled properly for evolved nitrogen oxides. (author)

Residue analyses on 2-amino-4-phenylthiazole, a piscine anesthetic, in fishes, 3

International Nuclear Information System (INIS)

Suzuki, Akira; Shimura, Masaru; Kikuchi, Takahiko; Sekizawa, Yasuharu

1977-01-01

The major biotransformation product of 2-amino-phenylthiazole in rainbow trout (Salmo gairdneri irideus) was isolated from water following exposure of fish to the anesthetic. The isolated crystalline metabolite was shown by means of ultraviolet, infrared and optical rotatory dispersion spectroscopy and gas chromatography to be identical to 2-amino-4-phenylthiazole-2-N-β-mono-D-glucopyranosiduronic acid, the major biotransformation product previously found in medaka (killifish, Oryzias latipes). The major biotransformation product in carp (Cyprinus carpio) was also identified as 2-amino-4-phenylthiazole-2-N-β-mono-D-glucopyranosiduronic acid by molecular sieve, thin layer and gas chromatography. Conversion of 2-amino-4-phenylthiazole to the N-glycuronyl conjugate was 8 and 12%, respectively, in rainbow trout and carp as shown by thin layer chromatography of extracts from fish treated with 3 H-labeled anesthetic. In addition, a minor metabolite of the anesthetic in rainbow trout was isolated as a yellowish-white crystalline powder and identified as 2-acetamino-4-(4'-hydroxyphenyl)-thiazole by means of ultraviolet and infrared spectroscopy, NMR and mass spectrometry. Chromatography suggested that this same metabolite was also formed in carp but in concentrations too low for isolation and definitive identification. (auth.)

Acid gas control process and apparatus for waste fired incinerators

International Nuclear Information System (INIS)

Kubin, P.Z.; Stepan, J.E.

1992-01-01

This patent describes a process for reducing noxious emission produced in a waste material incinerator. It comprises incinerating solid waste material in a furnace section of the waste material incinerator; providing an additive to an additive supply storage unit; conveying the additive to an additive injection means that communicates with the furnace section of the waste material incinerator; injecting the additive into a turbulent reaction zone of the furnace section such that acid gas content, acid dewpoint temperature and the level of corrosion in the incinerator are reduced

Simultaneous improvement of waste gas purification and nitrogen removal using a novel aerated vertical flow constructed wetland.

Science.gov (United States)

Zhang, Xinwen; Hu, Zhen; Ngo, Huu Hao; Zhang, Jian; Guo, Wenshan; Liang, Shuang; Xie, Huijun

2018-03-01

Insufficient oxygen supply is identified as one of the major factors limiting organic pollutant and nitrogen (N) removal in constructed wetlands (CWs). This study designed a novel aerated vertical flow constructed wetland (VFCW) using waste gas from biological wastewater treatment systems to improve pollutant removal in CWs, its potential in purifying waste gas was also identified. Compared with unaerated VFCW, the introduction of waste gas significantly improved NH 4 + -N and TN removal efficiencies by 128.48 ± 3.13% and 59.09 ± 2.26%, respectively. Furthermore, the waste gas ingredients, including H 2 S, NH 3 , greenhouse gas (N 2 O) and microbial aerosols, were remarkably reduced after passing through the VFCW. The removal efficiencies of H 2 S, NH 3 and N 2 O were 77.78 ± 3.46%, 52.17 ± 2.53%, and 87.40 ± 3.89%, respectively. In addition, the bacterial and fungal aerosols in waste gas were effectively removed with removal efficiencies of 42.72 ± 3.21% and 47.89 ± 2.82%, respectively. Microbial analysis results revealed that the high microbial community abundance in the VFCW, caused by the introduction of waste gas from the sequencing batch reactor (SBR), led to its optimized nitrogen transformation processes. These results suggested that the VFCW intermittently aerated with waste gas may have potential application for purifying wastewater treatment plant effluent and waste gas, simultaneously. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gas retention and release behavior in Hanford single-shell waste tanks

Energy Technology Data Exchange (ETDEWEB)

Stewart, C.W.; Brewster, M.E.; Gauglitz, P.A.; Mahoney, L.A.; Meyer, P.A.; Recknagle, K.P.; Reid, H.C.

1996-12-01

This report describes the current understanding of flammable gas retention and release in Hanford single-shell waste tanks based on theory, experimental results, and observations of tank behavior. The single-shell tanks likely to pose a flammable gas hazard are listed and described, and photographs of core extrusions and the waste surface are included. The credible mechanisms for significant flammable gas releases are described, and release volumes and rates are quantified as much as possible. The only mechanism demonstrably capable of producing large ({approximately}100 m{sup 3}) spontaneous gas releases is the buoyant displacement, which occurs only in tanks with a relatively deep layer of supernatant liquid. Only the double-shell tanks currently satisfy this condition. All release mechanisms believed plausible in single-shell tanks have been investigated, and none have the potential for large spontaneous gas releases. Only small spontaneous gas releases of several cubic meters are likely by these mechanisms. The reasons several other postulated gas release mechanisms are implausible or incredible are also given.

Effects of post-disposal gas generation in a repository for spent fuel, high-level waste and long-lived intermediate level waste sited in opalinus clay

International Nuclear Information System (INIS)

Johnson, L.; Marschall, P.; Zuidema, P.; Gribi, P.

2004-07-01

This comprehensive report issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at post-disposal gas generation in a repository for spent fuel and highly radioactive wastes in Opalinus clay strata. This study provides a comprehensive treatment of the issue of gas generation in a repository for spent fuel (SF), vitrified high-level waste (HLW) and long-lived intermediate-level waste (ILW), sited in the Opalinus clay of the Zuercher Weinland in northern Switzerland. The issue of how gas generation in and transport from waste repositories may influence disposal system performance has been under study for many years, both at Nagra and internationally. The report consists of three main parts: (i) A synthesis of basic information on the host rock and on details of repository construction; (ii) A discussion on gas transport characteristics of the engineered barrier system and the geosphere; (iii) A discussion on the effects of gas on system performance, based on the available information on gas generation, gas transport properties and gas pathways provided in the previous parts of the report. Simplified model calculations based on a mass balance approach for the gas generated within the repository are presented and discussed

Improving cost-effectiveness for the furnace in a full-scale refinery plant with reuse of waste tail gas fuel

Energy Technology Data Exchange (ETDEWEB)

Lee, Chien-Li [Department of Leisure and Recreation Management, Diwan University, Tainan (China); Hou, Shuhn-Shyurng [Department of Mechanical Engineering, Kun Shan University (China); Lee, Wen-Jhy [Department of Environmental Engineering, National Cheng Kung University (China); Jou, Chih-Ju G. [Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, 2, Juoyue Rd., Nantz District, Kaohsiung 811 (China)

2010-02-15

The waste tail gas fuel emitted from refinery plant in Taiwan e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement fuel. In this study, it was slowly added to the fuel stream of a heater furnace to replace natural gas for powering a full-scale distillation process. The waste tail gas fuel contained on average 60 mol% of hydrogen. On-site experimental results show that both the flame length and orange-yellowish brightness decrease with increasing proportion of waste gas fuel in the original natural gas fuel. Moreover, the adiabatic flame temperature increases as the content of waste gas fuel is increased in the fuel mixture since waste gas fuel has a higher adiabatic flame temperature than that of natural gas. The complete replacement of natural gas by waste gas fuel for a heater furnace operating at 70% loading (i.e. 3.6 x 10{sup 7} kcal/h of combustion capacity) will save 5.8 x 10{sup 6} m{sup 3} of natural gas consumption, and 3.5 x 10{sup 4} tons (or 53.4%) of CO{sub 2} emission annually. Recovering and reusing the waste tail gas fuel as natural gas replacement will achieve tremendous savings of natural gas usage and effectively lower the emission of carbon dioxide. (author)

Flaring versus thermal incineration of waste gases in the oil and gas industry

International Nuclear Information System (INIS)

Smolarski, G.M.

1999-01-01

The efficient combustion of waste gases at oil processing plants, battery or well sites is discussed. Several problem situations are examined, field test results are reviewed, and custom design systems are explained including modifications to systems to conserve fuel. It is shown that combustion of waste gases in fuel efficient thermal incinerators is a practical means of disposal, particularly for sour or toxic gas of low heating value. These gases contain noxious compounds that may cause odours or adverse health effects. Results of a field tests of a portable in-situ incinerator show that compared to flaring (to oxide waste gas), incineration is a more efficient form of waste management. Emission tests also prove the superior performance of incineration. The feasibility of incinerating oil storage tank vapours was also demonstrated. Tests were also conducted with a fuel-efficient Glycol Still Off-Gas Incinerator which was developed to control toxic waste emissions. Glycol dehydration removes water vapour from natural gas. The key compounds that are removed by glycol are aromatic hydrocarbons or BTEX compounds (benzene, toluene, ethylbenzene and xylene), and sulphur compounds. The main design considerations for any incinerator are temperature, turbulence and residence time. An incinerator exit temperature of 760 degrees C is generally needed to reduce sulphur compounds. 2 refs., 8 tabs., 7 figs

Norm waste in oil and gas industry: The Syrian experience

International Nuclear Information System (INIS)

Al-Masri, M.S.; Suman, H.

2001-01-01

This paper describes the Syrian experience in respect to Naturally Occurring Radioactive Materials (NORM) waste in Syrian oil and gas industry. NORM can be concentrated and accumulated in tubing and surface equipment of oil and gas production lines in the form of scale and sludge. NORM waste (scale, sludge, production water) is therefore generated during cleaning, physical or chemical treatment of streams. Uncontrolled disposal of this type of waste could lead to environmental pollution, and thus eventually to exposure of members of the public. The presence of NORM in Syrian oil fields has been recognized since 1987 and AECS has initiated several studies, in cooperation with oil companies, to manage such type of waste. Three categories of NORM waste in Syrian oil fields were identified. Firstly, hard scales from either decontamination of contaminated equipment and tubular using high-pressure water systems or mechanical cleaning at site are considered to contain the highest levels of radium isotopes ( 226 Ra, 228 Ra, 224 Ra). Secondly, sludge wastes are generated with large amount but low levels of radium isotopes were found. Thirdly, contaminated soil with 226 Ra as a result of uncontrolled disposal of production water was also considered as NORM waste. The first waste type (scale) is stored in Standard storage barrels in a controlled area; the number of barrels is increasing with time. High levels of radium isotopes were found in these scales. The options for disposal of these wastes are still under investigations; one of the most predominant thinking is the re-injection into abundant wells. For sludge waste, plastic lined disposal pits were constructed in each area for temporary storage. Moreover, big gas power stations have been built and operated since the last ten years. Maintenance operations for these stations produce tens of tones of scales containing radon daughters, 210 Pb and 210 Po with relatively high concentrations. The common practice used to dispose

Considerations for reduction of gas generation in a low-level radioactive waste repository

International Nuclear Information System (INIS)

Cho, Chan Hee; Son, Jung Kwon; Lee, Myung Chan; Song, Myung Jae

1997-01-01

In a low-level radioactive waste repository, H 2 , CO 2 , and CH 4 will be generated principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. The metal corrosion model incorporates a three-stage process encompassing aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. A prediction is made for gas concentrations and generation rates over an assessment period of ten thousand years in a radioactive waste repository. The results suggest that H 2 is the principal gas generated within the radioactive waste cavern. The generation rates of CO 2 and CH 4 are likely to be insignificant by comparison with H 2 . Therefore, an effective way to decrease gas generation in a radioactive waste repository seems to be to reduce metal content since the generation rate of H 2 is most sensitive to the concentration of steel

Flammable gas tank waste level reconcilliation tank 241-SX-102

International Nuclear Information System (INIS)

Brevick, C.H.; Gaddie, L.A.

1997-01-01

Fluoro Dynel Northwest (FDNW) was authorized to address flammable gas issues by reconciling the unexplained surface level increases in Tank 24 1-S-1 1 1 (S-I 1 1, typical). The trapped gas evaluation document (ref 1) states that Tank SX-102 exceeds the 25% of the lower flammable limit (FL) criterion (ref 2), based on a surface level rise evaluation. The Waste Storage Tank Status and Leak Detection Criteria document, commonly referred to as the ''Wallet Report'' is the basis for this letter report (ref 3). The Wallet Report is also a part of the trapped gas evaluation document criteria. The Wallet Report contains various tank information, including: physical information, status, levels, and dry wells, see Appendix A. The unexplained waste level rises were attributed to the production and retention of gas in the column of waste corresponding to the unacquainted for surface level rise. From 1973 through 1980, the Wallet Report tracked Tank S- 102 transfers and reported a net cumulative change of 19.95 in. This surface level increase is from an unknown source or is unacquainted for. Duke Engineering and Services Hanford (DASH) and Leached Martin Hanford Corporation (LMHC) are interested in determining the validity of the unexplained surface level changes reported in the 0611e Wallet Report based upon other corroborative sources of data. The purpose of this letter report is to assemble detailed surface level and waste addition data from daily tank records, logbooks, and other corroborative data that indicate surface levels, and to reconcile the cumulative unacquainted for surface level changes as shown in the Wallet Report from 1973 through 1980

Protocol for the quantification of greenhouse gas emissions from waste management activities

International Nuclear Information System (INIS)

2013-10-01

The Waste Sector GHG Protocol is intended to provide guidelines for calculating and reporting greenhouse gas (GHG) emissions associated with a waste management service, over a specific time period (usually one year) and based on simple operational data. The Protocol itself has evolved with time, going through 4 version updates. The different versions correspond to evolutions initiated by the original Entreprises pour l'Environnement Working Group (Seche Environnement, Suez Environnement and Veolia Environnement) but also to the suggestions and feedback provided by several waste associations that have reviewed and commented on the Protocol. As a result, several worldwide associations have validated and used the Protocol for their own greenhouse gas inventories. The version 5 of the Waste Sector GHG Protocol has received the 'Built on the GHG Protocol' label. With such label, the Waste Sector Protocol reinforces its desire to be the reference tool for the waste sector by ensuring its users of a total and transparent coherence and conformity with the GHG Protocol Corporate Standard's requirements. The Protocol is also available on the following web page: http://www.ghgprotocol.org/Tools-Built-on-GHG-Protocol. The Waste Sector GHG Protocol aims at: Providing a consistent and transparent approach to quantify, report and verify GHG direct (scope 1), indirect (scope 2) and avoided emissions of waste management actors; Establishing best practice across the waste sector for the implementation of coherent and homogeneous GHG emissions inventories; Explaining waste sector's particularities in terms of GHG emissions (diffuse emission from landfills, GHG avoided emissions, carbon sequestration); Helping companies to take proper commitments and stakeholders to understand and verify those commitments. The Protocol consists of a manual with two additional documents: A 'Frequently Asked Questions' document; A 'Follow-up of modifications

Laboratory optimization tests of technetium decontamination of Hanford Waste Treatment Plant low activity waste melter off-gas condensate simulant

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, Kathryn M.L. [Savannah River Site (SRS), Aiken, SC (United States); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States)

2015-11-01

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable simplified operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste.

Potential for the energetic use of waste gas in Flanders; Potentieel voor het energetisch gebruik van stortgassen in Vlaanderen

Energy Technology Data Exchange (ETDEWEB)

De Spiegeleer, E. [Vlaamse Instelling voor Technologisch Onderzoek, Mol (Belgium)

1999-03-01

The department of Natural Resources and Energy of the Ministry of the Flemish Community wanted to know the stand of affairs of the use of waste gas on the Flemish landfills in 1998. On the basis of a multi-phase model for waste gas production (according Dutch model) and data provided by the operators, the waste gas potential could be calculated for each landfill. The total waste gas production in Flanders is estimated at 75 million m3 in 1999. This brings the extracting amount of waste gas at 60 million m3 (in optimal circumstances, extracting efficiency 80%). Because the activities will continue for some years on categorie2 landfills, the waste gas production will increase. But the global waste gas potential will decrease as an effect of the evolution in the composition (less organic material) and the amount of waste that will be dumped, plus the landfills will be closed gradually. The possible savings of primary energy and the reduced CO2-emissions by the energetic apply of the global waste potential in Flanders is being estimated at about 695.000 GJ or 63.000 ton CO2. The generation of electricity with the help of a gas engine-generator unit is from technical and economical point of view the most achievable option for the operators. The price of the delivered energy is decisive for the cost-effectiveness of concrete investment projects. Only subsidies of the government makes the pay-back time for waste gas projects acceptable.

Gas cylinder disposal pit remediation waste minimization and management

International Nuclear Information System (INIS)

Alas, C.A.; Solow, A.; Criswell, C.W.; Spengler, D.; Brannon, R.; Schwender, J.M.; Eckman, C.K.; Rusthoven, T.

1995-01-01

A remediation of a gas cylinder disposal pit at Sandia National Laboratories, New Mexico has recently been completed. The cleanup prevented possible spontaneous releases of hazardous gases from corroded cylinders that may have affected nearby active test areas at Sandia's Technical Area III. Special waste management, safety, and quality plans were developed and strictly implemented for this project. The project was conceived from a waste management perspective, and waste minimization and management were built into the planning and implementation phases. The site layout was planned to accommodate light and heavy equipment, storage of large quantities of suspect soil, and special areas to stage and treat gases and reactive chemicals removed from the pit, as well as radiation protection areas. Excavation was a tightly controlled activity using experienced gas cylinder and reactive chemical specialists. Hazardous operations were conducted at night under lights, to allow nearby daytime operations to function unhindered. The quality assurance plan provided specific control of, and documentation for, critical decisions, as well as the record of daily operations. Both hand and heavy equipment excavation techniques were utilized. Hand excavation techniques were utilized. Hand excavation techniques allows sealed glass containers to be exhumed unharmed. In the end, several dozen thermal batteries; 5 pounds (2.3 kg) of lithium metal; 6.6 pounds (3.0 kg) of rubidium metal; several kilograms of unknown chemicals; 140 cubic yards (107 cubic meters) of thorium-contaminated soil; 270 cubic yards (205 cubic meters) of chromium-contaminated soil; and 450 gas cylinders, including 97 intact cylinders containing inert, flammable, toxic, corrosive, or oxidizing gases were removed and effectively managed to minimize waste

Models for recurrent gas release event behavior in hazardous waste tanks

International Nuclear Information System (INIS)

Anderson, D.N.; Arnold, B.C.

1994-08-01

Certain radioactive waste storage tanks at the United States Department of Energy Hanford facilities continuously generate gases as a result of radiolysis and chemical reactions. The congealed sludge in these tanks traps the gases and causes the level of the waste within the tanks to rise. The waste level continues to rise until the sludge becomes buoyant and ''rolls over'', changing places with heavier fluid on top. During a rollover, the trapped gases are released, resulting, in a sudden drop in the waste level. This is known as a gas release event (GRE). After a GRE, the wastes leading to another GRE. We present nonlinear time waste re-congeals and gas again accumulates leading to another GRE. We present nonlinear time series models that produce simulated sample paths that closely resemble the temporal history of waste levels in these tanks. The models also imitate the random GRE, behavior observed in the temporal waste level history of a storage tank. We are interested in using the structure of these models to understand the probabilistic behavior of the random variable ''time between consecutive GRE's''. Understanding the stochastic nature of this random variable is important because the hydrogen and nitrous oxide gases released from a GRE, are flammable and the ammonia that is released is a health risk. From a safety perspective, activity around such waste tanks should be halted when a GRE is imminent. With credible GRE models, we can establish time windows in which waste tank research and maintenance activities can be safely performed

Hanford Low-Activity Waste Processing: Demonstration of the Off-Gas Recycle Flowsheet - 13443

Energy Technology Data Exchange (ETDEWEB)

Ramsey, William G.; Esparza, Brian P. [Washington River Protection Solutions, LLC, Richland, WA 99532 (United States)

2013-07-01

Vitrification of Hanford Low-Activity Waste (LAW) is nominally the thermal conversion and incorporation of sodium salts and radionuclides into borosilicate glass. One key radionuclide present in LAW is technetium-99. Technetium-99 is a low energy, long-lived beta emitting radionuclide present in the waste feed in concentrations on the order of 1-10 ppm. The long half-life combined with a high solubility in groundwater results in technetium-99 having considerable impact on performance modeling (as potential release to the environment) of both the waste glass and associated secondary waste products. The current Hanford Tank Waste Treatment and Immobilization Plant (WTP) process flowsheet calls for the recycle of vitrification process off-gas condensates to maximize the portion of technetium ultimately immobilized in the waste glass. This is required as technetium acts as a semi-volatile specie, i.e. considerable loss of the radionuclide to the process off-gas stream can occur during the vitrification process. To test the process flowsheet assumptions, a prototypic off-gas system with recycle capability was added to a laboratory melter (on the order of 1/200 scale) and testing performed. Key test goals included determination of the process mass balance for technetium, a non-radioactive surrogate (rhenium), and other soluble species (sulfate, halides, etc.) which are concentrated by recycling off-gas condensates. The studies performed are the initial demonstrations of process recycle for this type of liquid-fed melter system. This paper describes the process recycle system, the waste feeds processed, and experimental results. Comparisons between data gathered using process recycle and previous single pass melter testing as well as mathematical modeling simulations are also provided. (authors)

MAC-sparing effect of nitrous oxide in sevoflurane anesthetized sheep and its reversal with systemic atipamezole administration

Science.gov (United States)

Scanu, Antonio; Melosu, Valentino; Careddu, Giovanni Mario; Sotgiu, Giovanni

2018-01-01

Introduction Nitrous oxide (N2O) is an anesthetic gas with antinociceptive properties and reduces the minimum alveolar concentration (MAC) for volatile anesthetic agents, potentially through mechanisms involving central alpha2-adrenoceptors. We hypothesized that 70% N2O in the inspired gas will significantly reduce the MAC of sevoflurane (MACSEVO) in sheep, and that this effect can be reversed by systemic atipamezole. Materials and methods Animals were initially anesthetized with SEVO in oxygen (O2) and exposed to an electrical current as supramaximal noxious stimulus in order to determine MACSEVO (in duplicates). Thereafter, 70% N2O was added to the inspired gas and the MAC re-determined in the presence of N2O (MACSN). A subgroup of sheep were anesthetized a second time with SEVO/N2O for re-determination of MACSN, after which atipamezole (0.2 mg kg-1, IV) was administered for MACSNA determinations. Sheep were anesthetized a third time, initially with only SEVO/O2 to re-determine MACSEVO, after which atipamezole (0.2 mg kg-1, IV) was administered for determination of MACSA. Results MACSEVO was 2.7 (0.3)% [mean (standard deviation)]. Addition of N2O resulted in a 37% reduction of MACSEVO to MACSN of 1.7 (0.2)% (p <0.0001). Atipamezole reversed this effect, producing a MACSNA of 3.1 (0.7)%, which did not differ from MACSEVO (p = 0.12). MACSEVO did not differ from MACSA (p = 0.69). Cardiorespiratory variables were not different among experimental groups except a lower ETCO2 in animals exposed to SEVO/N2O. Conclusions N2O produces significant MACSEVO-reduction in sheep; this effect is completely reversed by IV atipamezole confirming the involvement of alpha2-adrenoreceptors in the MAC-sparing action of N2O. PMID:29315308

Electron beam application in gas waste treatment in China

International Nuclear Information System (INIS)

Wu Haifeng

2003-01-01

In the most recent decade, electron beam waste treatment technology attracted serious attention from environment policymaker and industrial leaders in power industry in China. Starting in middle of 1980's, Chinese research institute began experiment of electron beam treatment on flue gas. By the end of 2000, two 10,000 cubic meters per hour small scale electron beam gas purifying station were established in Sichuang province and Beijing. Several electron beam gas purifying demonstration projects are under construction. With robust economy and strong energy demand, needless to say, in near future, electron beam gas purifying technology will have a bright prospect in China. (author)

Process and device for decontamination of the waste gas of the fuel circuit of a fusion reactor from tritium and/or deuterium in waste gas containing them in chemically bound form

International Nuclear Information System (INIS)

Penzhorn, R.D.; Glugla, M.

1987-01-01

The invention concerns a process and a device for the decontamination of the wate gases of the fuel circuit of a fusion reactor from tritum and/or deuterium in waste gas containing them in chemically bound form, in which the waste gas is taken over an oxidation catalyst and then over a hot metal bed, tritium and/or deuterium is released from its compounds, separated from the waste gas and is returned to the fuel circuit. The process is intended to prevent losses of tritum and/or deuterium by permeation and the high loading of the hot metal getter materials, as occurs in the previously known corresponding process, and to avoid the formation of nitrogen oxides. This is achieved by: a) The catalytic oxidation reaction being carried out at a temperature of 200 0 C to 300 0 C. b) The gas mixture then being brought into contact with a hot metal bed at 200 0 C to 300 0 C to remove the remaining O 2 and for the selective conversion of the proportion of water into the hydrogen isotope. c) The gas mixture being brought into contact with a diaphragm made of palladium or a palladium-silver alloy at 400 0 C to 450 0 C to decompose the ammonia, all the released hydrogen isotope being passed through the diaphragm, separated from the remaining waste gas flow and removed. (orig.) [de

Critique of Hanford Waste Vitrification Plant off-gas sampling requirements

International Nuclear Information System (INIS)

Goles, R.W.

1996-03-01

Off-gas sampling and monitoring activities needed to support operations safety, process control, waste form qualification, and environmental protection requirements of the Hanford Waste Vitrification Plant (HWVP) have been evaluated. The locations of necessary sampling sites have been identified on the basis of plant requirements, and the applicability of Defense Waste Processing Facility (DWPF) reference sampling equipment to these HWVP requirements has been assessed for all sampling sites. Equipment deficiencies, if present, have been described and the bases for modifications and/or alternative approaches have been developed

Gas flow in and out of a nuclear waste container

International Nuclear Information System (INIS)

Zwahlen, E.D.; Pigford, T.H.; Chambre, P.L.; Lee, W.W.L.

1989-05-01

We analyze the flow of gases out of and into a high-level-waste container in the unsaturated tuff of Yucca Mountain. Containers are expected to fail eventually by localized cracks and penetrations. Even though the penetrations may be small, argon gas initially in the hot container can leak out. As the waste package cools, the pressure inside the container can become less than atmospheric, and air can leak in. 14 C released from the hot fuel-cladding surface can leak out of penetrations, and air inleakage can mobilize additional 14 C and other volatile radioactive species as it oxidizes the fuel cladding and the spent fuel. In an earlier paper we studied the gas flow through container penetrations occurring at the time of emplacement. Here we analyze the flow of gas for various penetration sizes occurring at 300 years. 3 refs., 2 figs

Combination gas producing and waste-water disposal well

Science.gov (United States)

Malinchak, Raymond M.

1984-01-01

The present invention is directed to a waste-water disposal system for use in a gas recovery well penetrating a subterranean water-containing and methane gas-bearing coal formation. A cased bore hole penetrates the coal formation and extends downwardly therefrom into a further earth formation which has sufficient permeability to absorb the waste water entering the borehole from the coal formation. Pump means are disposed in the casing below the coal formation for pumping the water through a main conduit towards the water-absorbing earth formation. A barrier or water plug is disposed about the main conduit to prevent water flow through the casing except for through the main conduit. Bypass conduits disposed above the barrier communicate with the main conduit to provide an unpumped flow of water to the water-absorbing earth formation. One-way valves are in the main conduit and in the bypass conduits to provide flow of water therethrough only in the direction towards the water-absorbing earth formation.

Project on effects of gas in underground storage facilities for radioactive waste (Pegasus project)

International Nuclear Information System (INIS)

Haijtink, B.; McMenamin, T.

1993-01-01

Whereas the subject of gas generation and gas release from radioactive waste repositories has gained in interest on the international scene, the Commission of the European Communities has increased its research efforts on this issue. In particular, in the fourth five-year R and D programme on management and storage of radioactive waste (1990-94), a framework has been set up in which research efforts on the subject of gas generation and migration, supported by the CEC, are brought together and coordinated. In this project, called Pegasus, about 20 organizations and research institutes are involved. The project covers theoretical and experimental studies of the processes of gas formation and possible gas release from the different waste types, LLW, ILW and HLW, under typical repository conditions in suitable geological formations such as clay, salt and granite. In this report the present status of the various research activities are described and 13 papers have been selected

Influence of fuel composition on the non-oxidizing heating of steel in a waste gas atmosphere

Energy Technology Data Exchange (ETDEWEB)

Minkler, W [LOI Industrieofenanlagen G.m.b.H., Essen (Germany, F.R.)

1979-04-01

On the basis of a number of graphs and data on theoretical combustion temperatures and the difference between the heating value of the fuel and the waste gas in respect of 1 m/sup 3/ of waste gas, the author demonstrates the influence of fuel composition on the non-oxidizing heating of steel in a waste gas atmosphere derived from five different fuels. A rotary-hearth furnace is described for the non-oxidizing heating of pressings from plain carbon and alloy steel.

Quantifying greenhouse gas emissions from municipal solid waste dumpsites in Cameroon.

Science.gov (United States)

Ngwabie, N Martin; Wirlen, Yvette L; Yinda, Godwin S; VanderZaag, Andrew C

2018-03-02

Open dumpsites that receive municipal solid waste are potentially significant sources of greenhouse gas (GHG) emissions into the atmosphere. There is little data available on emissions from these sources, especially in the unique climate and management of central Africa. This research aimed at quantifying CH 4 , N 2 O and CO 2 emissions from two open dumpsites in Cameroon, located in Mussaka-Buea, regional headquarters of the South West Region and in Mbellewa-Bamenda, regional headquarters of the North West Region. Emissions were measured during the wet season (May 2015 and August 2016) at the Mussaka and Mbellewa dumpsites respectively. Dumpsite surfaces were partitioned into several zones for emission measurements, based on the current activity and the age of the waste. Static flux chambers were used to quantify gas emission rates thrice a day (mornings, afternoons and evenings). Average emissions were 96.80 ± 144 mg CH 4 m -2  min -1 , 0.20 ± 0.43 mg N 2 O m -2  min -1 and 224.78 ± 312 mg CO 2 m -2  min -1 in the Mussaka dumpsite, and 213.44 ± 419 mg CH 4 m -2  min -1 , 0.15 ± 0.15 mg N 2 O m -2  min -1 and 1103.82 ± 1194 mg CO 2 m -2  min -1 at the Mbellewa dumpsite. Emissions as high as 1784 mg CH 4 m -2  min -1 , 2.3 mg N 2 O m -2  min -1 and 5448 mg CO 2 m -2  min -1 were measured from both dumpsites. Huge variations observed in emissions between the different zones on the waste surface were likely a result of the heterogeneous nature of the waste, different stages in waste decomposition and different environmental conditions within the waste. Management activities that disturb waste, such as spreading and compressing potentially increase gas emissions, while covering waste with a layer of soil potentially mitigate gas emissions. Recommendations were for dumpsites to be upgraded to sanitary landfills, and biogas production from such landfills should be exploited to reduce CH 4 emissions

Dust removal from waste gas arising from fluidized beds

International Nuclear Information System (INIS)

Soltys, L.

1992-01-01

Two types dust removal equipment mostly useful for dust removal from waste gas from fluidized beds, i.e. electrofilters and pulsatory bag filters were presented. Their features and functional properties were compared. (author). 7 refs, 4 figs

Local Anesthetic-Induced Neurotoxicity

NARCIS (Netherlands)

Verlinde, Mark; Hollmann, Markus W.; Stevens, Markus F.; Hermanns, Henning; Werdehausen, Robert; Lirk, Philipp

2016-01-01

This review summarizes current knowledge concerning incidence, risk factors, and mechanisms of perioperative nerve injury, with focus on local anesthetic-induced neurotoxicity. Perioperative nerve injury is a complex phenomenon and can be caused by a number of clinical factors. Anesthetic risk

Possibilities for gas turbine and waste incinerator integration

NARCIS (Netherlands)

Korobitsyn, M.A.; Jellema, P.; Hirs, Gerard

1999-01-01

The aggressive nature of the flue gases in municipal waste incinerators does not allow the temperature of steam in the boiler to rise above 400°C. An increase in steam temperature can be achieved by external superheating in a heat recovery steam generator positioned behind a gas turbine, so that

FY 1994 report on the development of wood-waste/agri-waste pyrolytic gasification technology and utilization technology of gas product; 1994 nendo mokushitsukei haikibutsu no netsubunkai gas ka gijutsu to seisei gas no riyo gijutsu kaihatsu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-03-01

This 5-year joint project (FY 1990 to 1994) by Japan and the Philippines is aimed at joint research and development of (thermal decomposition/gasification and power generation system) for transforming large quantities of wood-wastes/agri-wastes left unutilized in the Philippines into electric power, in which thermal decomposition/gasification of the wastes is combined with a gas engine system. The field tests of the demonstration plant successfully produce power of 100 kW by burning only the low-calorie gas with a heating value near critical level for self-sustained combustion, obtained by gasification of sawdust by the fluidized gasifier and refined, attaining the object of the project. It is confirmed that a 200 to 300 kW class commercial plant can be designed and constructed basically by scaling up the 100 kW demonstration plant. The other data obtained by the field tests include those for improved operability and maintainability, gas purification, and reducing sizes of the facilities, including utility facilities. (NEDO)

TRU waste transportation -- The flammable gas generation problem

International Nuclear Information System (INIS)

Connolly, M.J.; Kosiewicz, S.T.

1997-01-01

The Nuclear Regulatory Commission (NRC) has imposed a flammable gas (i.e., hydrogen) concentration limit of 5% by volume on transuranic (TRU) waste containers to be shipped using the TRUPACT-II transporter. This concentration is the lower explosive limit (LEL) in air. This was done to minimize the potential for loss of containment during a hypothetical 60 day period. The amount of transuranic radionuclide that is permissible for shipment in TRU waste containers has been tabulated in the TRUPACT-II Safety Analysis Report for Packaging (SARP, 1) to conservatively prevent accumulation of hydrogen above this 5% limit. Based on the SARP limitations, approximately 35% of the TRU waste stored at the Idaho National Engineering and Environmental Lab (INEEL), Los Alamos National Lab (LANL), and Rocky Flats Environmental Technology Site (RFETS) cannot be shipped in the TRUPACT-II. An even larger percentage of the TRU waste drums at the Savannah River Site (SRS) cannot be shipped because of the much higher wattage loadings of TRU waste drums in that site's inventory. This paper presents an overview of an integrated, experimental program that has been initiated to increase the shippable portion of the Department of Energy (DOE) TRU waste inventory. In addition, the authors will estimate the anticipated expansion of the shippable portion of the inventory and associated cost savings. Such projection should provide the TRU waste generating sites a basis for developing their TRU waste workoff strategies within their Ten Year Plan budget horizons

Experimental and modelling investigations of the biogeochemistry of gas production from low and intermediate level radioactive waste

International Nuclear Information System (INIS)

Small, Joe; Nykyri, Mikko; Helin, Mika; Hovi, Ulla; Sarlin, Tuija; Itaevaara, Merja

2008-01-01

The degradation of organic wastes and the corrosion of metallic wastes and steel containers in low and intermediate level radioactive waste (LLW/ILW) repositories are important processes that affect repository geochemistry and the speciation and transport of radionuclides. Gas is generated in association with these degradation processes and this has the potential to overpressure the repository, which can promote transport of groundwater and gas, and consequently radionuclide transport. Microbial activity plays an important role in organic degradation, corrosion and gas generation through the mediation of reduction-oxidation reactions. A large-scale gas generation experiment has been established at the LLW/ILW repository, Olkiluoto, Finland to examine gas generation from LLW in waste drums disposed of in the operational VLJ Repository (VLJ is a Finnish acronym which translates to 'reactor operating waste'). The experiment has monitored, for a period of 9 a, the rate and composition of gas generated, and the aqueous geochemistry and microbe populations present at various locations within the experiment. There is considerable heterogeneity within the experiment, such that pH is observed to vary from pH 5.5 to pH 10 between organic-rich waste and water associated with concrete. The heterogeneity results in competing anaerobic processes occurring together in the experiment but within different niches. Microbial activity initially dominant in organic waste has after 7 a reduced the alkalinity of the concrete influenced regions. The experiment has been modelled using a biogeochemical reaction-transport code (GRM) using a blind testing approach. Using independent data, the model was able to reproduce, within a factor of two, the rate of gas production. In addition, the model represented the main anaerobic microbial processes leading to methanogenesis and the observed spatial and temporal variations in aqueous and gaseous species. In order to model the experiment, its

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

International Nuclear Information System (INIS)

Gauglitz, P.A.; Rassat, S.D.; Powell, M.R.

1995-08-01

Several of the underground nuclear storage tanks at Hanford have been placed on a flammable gas watch list, because the waste is either known or suspected to generate, store, and episodically release flammable gases. Because retention and episodic release of flammable gases from these tanks containing radioactive waste slurries are critical safety concerns, Pacific Northwest Laboratory (PNL) is studying physical mechanisms and waste properties that contribute to the episodic gas release from these storage tanks. This study is being conducted for Westinghouse Hanford Company as part of the PNL Flammable Gas project. Previous investigations have concluded that gas bubbles are retained by the slurry or sludge that has settled at the bottom of the tanks; however, the mechanisms responsible for the retention of these bubbles are not well understood. Understanding the rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles and the dynamics of how these bubbles are released from the waste. The presence of gas bubbles is expected to affect the rheology of the sludge, specifically its viscosity and tensile and shear strengths, but essentially no literature data are available to assess the effect of bubbles. The objectives of this study were to conduct experiments and develop theories to understand better how bubbles are retained by slurries and sludges, to measure the effect of gas bubbles on the viscosity of simulated slurries, and to measure the effect of gas bubbles on the tensile and shear strengths of simulated slurries and sludges. In addition to accomplishing these objectives, this study developed correlations, based on the new experimental data, that can be used in large-scale computations of waste tank physical phenomena

Gas bubble retention and its effect on waste properties: Retention mechanisms, viscosity, and tensile and shear strengths

Energy Technology Data Exchange (ETDEWEB)

Gauglitz, P.A.; Rassat, S.D.; Powell, M.R. [and others

1995-08-01

Several of the underground nuclear storage tanks at Hanford have been placed on a flammable gas watch list, because the waste is either known or suspected to generate, store, and episodically release flammable gases. Because retention and episodic release of flammable gases from these tanks containing radioactive waste slurries are critical safety concerns, Pacific Northwest Laboratory (PNL) is studying physical mechanisms and waste properties that contribute to the episodic gas release from these storage tanks. This study is being conducted for Westinghouse Hanford Company as part of the PNL Flammable Gas project. Previous investigations have concluded that gas bubbles are retained by the slurry or sludge that has settled at the bottom of the tanks; however, the mechanisms responsible for the retention of these bubbles are not well understood. Understanding the rheological behavior of the waste, particularly of the settled sludge, is critical to characterizing the tendency of the waste to retain gas bubbles and the dynamics of how these bubbles are released from the waste. The presence of gas bubbles is expected to affect the rheology of the sludge, specifically its viscosity and tensile and shear strengths, but essentially no literature data are available to assess the effect of bubbles. The objectives of this study were to conduct experiments and develop theories to understand better how bubbles are retained by slurries and sludges, to measure the effect of gas bubbles on the viscosity of simulated slurries, and to measure the effect of gas bubbles on the tensile and shear strengths of simulated slurries and sludges. In addition to accomplishing these objectives, this study developed correlations, based on the new experimental data, that can be used in large-scale computations of waste tank physical phenomena.

Modelling greenhouse gas emissions for municipal solid waste management strategies in Ottawa, Ontario, Canada

Energy Technology Data Exchange (ETDEWEB)

Mohareb, Adrian K. [Technology Early Action Measures (TEAM) Office, 55 Murray Street, Suite 230, Ottawa, ON (Canada); Warith, Mostafa A.; Diaz, Rodrigo [Department of Civil Engineering, Ryerson University, 350 Victoria Street, Toronto, ON (Canada)

2008-09-15

Human-induced climate change, through the emission of greenhouse gases, may result in a significant negative impact on Earth. Canada is one of the largest per capita emitters of greenhouse gas, generating 720 megatonnes (Mt) carbon dioxide equivalents (CO{sub 2}e), or per capita emissions of 23.2 t CO{sub 2}e. The solid waste sector in Canada was directly responsible for 25 Mt CO{sub 2}e in 2001, of which 23 Mt CO{sub 2}e were produced by landfill gas (LFG). A modelling exercise was undertaken to determine greenhouse gas (GHG) emissions from the waste sector using the waste disposal, recycling, and composting data from Ottawa, Ontario, Canada for the year 2003, as well as the results of an audit of residential units performed in the same year. This evaluation determined that, among the options examined, waste incineration, further source separation of recyclables, and anaerobic digestion of an organic wastes have the greatest benefits for reducing GHG emissions in the City of Ottawa's waste sector. Challenges surrounding the installation of incineration facilities in Canada suggest that improved diversion of recyclable materials and anaerobic digestion of organic materials are the optimal options for the City of Ottawa to pursue. (author)

Composition and activity variations in bulk gas of drum waste packages of Paks NPP

International Nuclear Information System (INIS)

Molnar, M.; Palcsu, L.; Svingor, E.; Szanto, Zs.; Futo, I.; Ormai, P.

2001-01-01

To obtain reliable estimates of the quantities and rates of the gas production a series of measurements was carried out in drum waste packages generated and temporarily stored at the site of Paks Nuclear Power Plant (Paks NPP). Ten drum waste packages were equipped with sampling valves for repeated sampling. Nine times between 04/02/2000 and 19/07/2001 qualitative gas component analyses of bulk gases of drums were executed. Gas samples were delivered to the laboratory of the ATOMKI for tritium and radiocarbon content measurements.(author)

Laboratory Optimization Tests of Technetium Decontamination of Hanford Waste Treatment Plant Direct Feed Low Activity Waste Melter Off-Gas Condensate Simulant

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-12-23

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable less integrated operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste.

Characterization of industrial waste from a natural gas distribution company and management strategies: a case study of the East Azerbaijan Gas Company (Iran).

Science.gov (United States)

Taghipour, Hassan; Aslhashemi, Ahmad; Assadi, Mohammad; Khodaei, Firoz; Mardangahi, Baharak; Mosaferi, Mohammad; Roshani, Babak

2012-10-01

Although a fundamental prerequisite for the successful implementation of any waste management plan is the availability of sufficient and accurate data, there are few available studies regarding the characterization and management of gas distribution company waste (GDCW). This study aimed to characterize the industrial waste generated by the East Azerbaijan Gas Distribution Company (EAGDC) and to present environmental management strategies. The EAGDC serves 57 cities and 821 villages with a total population of more than 2.5 million as well as numerous industrial units. The methodology of this study was based on a checklist of data collected from each zone of the company, site visits (observation), and quantity and quality analysis according to the formal data available from different zones. The results indicate that more than 35 different kinds of industrial solid waste are generated in different industrial installations. The most important types of generated waste include empty barrels (including mercaptans, diesel fuel, deionized waters and oil), faulty gas meters and regulators, a variety of industrial oils, sleeves, filter elements and faulty pipes, valves and fittings. The results indicated that, currently, GDCW is generally handled and disposed of with domestic waste, deposited in companies' installation yards and stores or, sometimes, recycled through non-scientific approaches that can create health risks to the public and the environment, even though most of the GDCW was determined to be recyclable or reusable materials. This study concludes that gas distribution companies must pay more attention to source reduction, recycling and reusing of waste to preserve natural resources, landfill space and the environment.

Environmental release of carbon-14 gas from a hypothetical nuclear waste repository

International Nuclear Information System (INIS)

Lehto, M.A.; Merrell, G.B.

1994-01-01

Radioisotopes may form gases in a spent nuclear fuel waste package due to elevated temperatures or degradation of the fuel rods. Radioactive carbon-14, as gaseous carbon dioxide, is one of the gaseous radioisotopes of concern at an underground disposal facility for spent nuclear fuel and high-level radioactive waste. Carbon-14 dioxide may accumulate inside an intact waste container. Upon breach of the container, a potentially large pulse of carbon-14 dioxide gas may be released to the surrounding environment, followed by a lower, long-term continuous release. If the waste were disposed of in an unsaturated geologic environment, the carbon-14 gas would begin to move through the unsaturated zone to the accessible environment. This study investigates the transport of radioactive carbon-14 gas in geologic porous media using a one-dimensional analytical solution. Spent nuclear fuel emplaced in a deep geologic repository located at a generic unsaturated tuff site is analyzed. The source term for the carbon-14 gas and geologic parameters was obtained from previously published materials. The one-dimensional analytical solution includes diffusion, advection, radionuclide retardation, and radioactive decay terms. Two hypothetical sites are analyzed. One is dominated by advective transport, and the other is dominated by diffusive transport. The dominant transport mechanism at an actual site depends on the site characteristics. Results from the simulations include carbon-14 dioxide travel times to the accessible environment and the total release to the environment over a 10,000-year period. The results are compared to regulatory criteria

[Effects of superphosphate addition on NH3 and greenhouse gas emissions during vegetable waste composting].

Science.gov (United States)

Yang, Yan; Sun, Qin-ping; Li, Ni; Liu, Chun-sheng; Li, Ji-jin; Liu, Ben-sheng; Zou, Guo-yuan

2015-01-01

To study the effects of superphosphate (SP) on the NH, and greenhouse gas emissions, vegetable waste composting was performed for 27 days using 6 different treatments. In addition to the controls, five vegetable waste mixtures (0.77 m3 each) were treated with different amounts of the SP additive, namely, 5%, 10%, 15%, 20% and 25%. The ammonia volatilization loss and greenhouse gas emissions were measured during composting. Results indicated that the SP additive significantly decreased the ammonia volatilization and greenhouse gas emissions during vegetable waste composting. The additive reduced the total NH3 emission by 4.0% to 16.7%. The total greenhouse gas emissions (CO2-eq) of all treatments with SP additives were decreased by 10.2% to 20.8%, as compared with the controls. The NH3 emission during vegetable waste composting had the highest contribution to the greenhouse effect caused by the four different gases. The amount of NH3 (CO2-eq) from each treatment ranged from 59.90 kg . t-1 to 81.58 kg . t-1; NH3(CO2-eq) accounted for 69% to 77% of the total emissions from the four gases. Therefore, SP is a cost-effective phosphorus-based fertilizer that can be used as an additive during vegetable waste composting to reduce the NH3 and greenhouse gas emissions as well as to improve the value of compost as a fertilizer.

Microbial Community in a Biofilter for Removal of Low Load Nitrobenzene Waste Gas.

Directory of Open Access Journals (Sweden)

Jian Zhai

Full Text Available To improve biofilter performance, the microbial community of a biofilter must be clearly defined. In this study, the performance of a lab-scale polyurethane biofilter for treating waste gas with low loads of nitrobenzene (NB (< 20 g m-3 h-1 was investigated when using different empty bed residence times (EBRT (64, 55.4 and 34 s, respectively. In addition, the variations of the bacterial community in the biofilm on the longitudinal distribution of the biofilters were analysed by using Illumina MiSeq high-throughput sequencing. The results showed that NB waste gas was successfully degraded in the biofilter. High-throughput sequencing data suggested that the phylum Actinobacteria and genus Rhodococcus played important roles in the degradation of NB. The variations of the microbial community were attributed to the different intermediate degradation products of NB in each layer. The strains identified in this study were potential candidates for purifying waste gas effluents containing NB.

Greenhouse gas contribution of municipal solid waste collection: A case study in the city of Istanbul, Turkey.

Science.gov (United States)

Korkut, Nafiz E; Yaman, Cevat; Küçükağa, Yusuf; Jaunich, Megan K; Demir, İbrahim

2018-02-01

This article estimates greenhouse gas emissions and global warming factors resulting from collection of municipal solid waste to the transfer stations or landfills in Istanbul for the year of 2015. The aim of this study is to quantify and compare diesel fuel consumption and estimate the greenhouse gas emissions and global warming factors associated with municipal solid waste collection of the 39 districts of Istanbul. Each district's greenhouse gas emissions resulting from the provision and combustion of diesel fuel was estimated by considering the number of collection trips and distances to municipal solid waste facilities. The estimated greenhouse gases and global warming factors for the districts varied from 61.2 to 2759.1 t CO 2 -eq and from 4.60 to 15.20 kg CO 2 -eq t -1 , respectively. The total greenhouse gas emission was estimated as 46.4E3 t CO 2 -eq. Lastly, the collection data from the districts was used to parameterise a collection model that can be used to estimate fuel consumption associated with municipal solid waste collection. This mechanistic model can then be used to predict future fuel consumption and greenhouse gas emissions associated with municipal solid waste collection based on projected population, waste generation, and distance to transfer stations and landfills. The greenhouse gas emissions can be reduced by decreasing the trip numbers and trip distances, building more transfer stations around the city, and making sure that the collection trucks are full in each trip.

Drug interactions: volatile anesthetics and opioids.

Science.gov (United States)

Glass, P S; Gan, T J; Howell, S; Ginsberg, B

1997-09-01

Multiple drugs are used to provide anesthesia. Volatile anesthetics are commonly combined with opioids. Several studies have demonstrated that small doses of opioid (i.e., within the analgesic range) result in a marked reduction in minimum alveolar concentration (MAC) of the volatile anesthetic that will prevent purposeful movement in 50% of patients at skin incision). Further increases in opioid dose provide only a further small reduction in MAC. Thus, a ceiling effect of the opioid is observed at a MAC value of the volatile anesthetic equal to its MAC awake. Recovery from anesthesia when an opioid is combined with a volatile anesthetic is dependent on the rate of decrease of both drugs to their respective concentrations that are associated with adequate spontaneous ventilation and awakening. Through an understanding of the pharmacodynamic interaction of volatile anesthetics with opioids and the pharmacokinetic processes responsible for the recovery from drug effect, optimal dosing schemes can thus be developed. A review of these pharmacodynamic and pharmacokinetic principles that will allow clinicians to administer drugs to provide a more optimal anesthetic is provided.

Using TOUGH2 to model the coupled effects of gas generation, repository consolidation, and multiphase brine and gas flow at the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Freeze, G.A.; Larson, K.W.; Davies, P.B.; Webb, S.W.

1995-01-01

The Waste Isolation Pilot Plant (WIPP) is a US Department of Energy facility designed to demonstrate the safe underground disposal of transuranic waste. Following waste emplacement, each room will be backfilled with crushed salt. Due to deviatoric stress introduced by excavation, the walls of the waste disposal rooms in the repository will deform over time, consolidating waste containers and salt backfill, thereby decreasing the void volume of the repository. Long-term repository assessment must consider the processes of gas generation, room closure and expansion due to salt creep, and multiphase (brine and gas) fluid flow, as well as the complex coupling between these three processes. Stone (1992) used the mechanical creep closure code SANCHO to simulate the closure of a single, perfectly sealed disposal room filled with waste and backfill. The results of the SANCHO f-series simulations provide a relationship between gas generation, room closure, and room pressure. Several methods for coupling this relationship with multiphase fluid flow into and out of a room were examined by Freeze et al. TOUGH2 was employed to couple the processes of gas generation, room closure/consolidation, and multiphase brine and gas flow. Two empirically-based methods for approximating salt creep and room consolidation were implemented in TOUGH2: the pressure-time-porosity line interpolation approach and the fluid-phase-salt approach. Both approaches utilized links to the SANCHO f-series simulation results to calculate room-void-volume changes with time during a simulation

18 CFR 2.400 - Statement of interpretation of waste concerning natural gas as the primary energy source for...

Science.gov (United States)

2010-04-01

... interpretation of waste concerning natural gas as the primary energy source for qualifying small power production... concerning natural gas as the primary energy source for qualifying small power production facilities. For purposes of deciding whether natural gas may be considered as waste as the primary energy source pursuant...

Molten salt hazardous waste disposal process utilizing gas/liquid contact for salt recovery

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.

1984-01-01

The products of a molten salt combustion of hazardous wastes are converted into a cooled gas, which can be filtered to remove hazardous particulate material, and a dry flowable mixture of salts, which can be recycled for use in the molten salt combustion, by means of gas/liquid contact between the gaseous products of combustion of the hazardous waste and a solution produced by quenching the spent melt from such molten salt combustion. The process results in maximizing the proportion of useful materials recovered from the molten salt combustion and minimizing the volume of material which must be discarded. In a preferred embodiment a spray dryer treatment is used to achieve the desired gas/liquid contact

Reduction of energy cost and CO2 emission for the furnace using energy recovered from waste tail-gas

International Nuclear Information System (INIS)

Jou, Chih-Ju G.; Wu, Chung-Rung; Lee, Chien-Li

2010-01-01

In this research, the waste tail gas emitted from petrochemical processes, e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement of natural gas (NG). On-site experimental results show that both the flame length and orange-yellowish brightness decrease with more proportion of waste gas fuel added to the natural gas, and that the adiabatic temperature of the mixed fuel is greater than 1800 o C. A complete replacement of natural gas by the recovered waste gas fuel will save 5.8 x 10 6 m 3 of natural gas consumption, and 3.5 x 10 4 tons of CO 2 emission annually. In addition, the reduction of residual O 2 concentration in flue gases from 4% to 3% will save 1.1 x 10 6 m 3 of natural gas consumption, reduce 43.0% of NO x emission, and 1.3 x 10 3 tons of CO 2 emission annually. Thus, from the viewpoint of the overall economics and sustainable energy policy, recovering the waste tail gas energy as an independent fuel source to replace natural gas is of great importance for saving energy, reducing CO 2 emission reduction, and lowering environmental impact.

Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

International Nuclear Information System (INIS)

Gillow, J.B.; Francis, A.

2011-01-01

Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid (∼70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO 2 ) and methane (CH 4 ) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

Sodium channels as targets for volatile anesthetics

Directory of Open Access Journals (Sweden)

Karl F. Herold

2012-03-01

Full Text Available The molecular mechanisms of modern inhaled anesthetics although widely used in clinical settings are still poorly understood. Considerable evidence supports effects on membrane proteins such as ligand- and voltage-gated ion channels of excitable cells. Na+ channels are crucial to action potential initiation and propagation, and represent potential targets for volatile anesthetics. Inhibition of presynaptic Na+ channels leads to reduced neurotransmitter release at the synapse and could therefore contribute to the mechanisms by which volatile anesthetics produce their characteristic effects: amnesia, unconsciousness, and immobility. Early studies on crayfish and squid giant axon showed inhibition of Na+ currents by volatile anesthetics. Subsequent studies using native neuronal preparations and heterologous expression systems with various mammalian Na+ channel isoforms implicated inhibition of presynaptic Na+ channels in anesthetic actions. Volatile anesthetics reduce peak Na+ current and shift the voltage of half-maximal steady-state inactivation towards more negative potentials, thus stabilizing the fast-inactivated state. Furthermore recovery from fast-inactivation is slowed together with an enhanced use-dependent block during pulse train protocols. These effects can reduce neurotransmitter release by depressing presynaptic excitability, depolarization and Ca entry, and ultimately transmitter release. This reduction in transmitter release is more portent for glutamatergic vs. GABAergic terminals. Involvement of Na+ channel inhibition in mediating the immobility caused by volatile anesthetics has been demonstrated in animal studies, in which intrathecal infusion of the Na+ channel blocker tetrodotoxin increases volatile anesthetic potency, whereas infusion of the Na+ channels agonist veratridine reduces anesthetic potency. These studies indicate that inhibition of presynaptic Na+ channels by volatile anesthetics is involved in mediating some of

Laboratory Optimization Tests of Decontamination of Cs, Sr, and Actinides from Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, K. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-01-06

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable less integrated operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also substantially decrease the LAW vitrification mission duration and quantity of glass waste.

Recycling of blast furnace sludge by briquetting with starch binder: Waste gas from thermal treatment utilizable as a fuel.

Science.gov (United States)

Drobíková, Klára; Plachá, Daniela; Motyka, Oldřich; Gabor, Roman; Kutláková, Kateřina Mamulová; Vallová, Silvie; Seidlerová, Jana

2016-02-01

Steel plants generate significant amounts of wastes such as sludge, slag, and dust. Blast furnace sludge is a fine-grained waste characterized as hazardous and affecting the environment negatively. Briquetting is one of the possible ways of recycling of this waste while the formed briquettes serve as a feed material to the blast furnace. Several binders, both organic and inorganic, had been assessed, however, only the solid product had been analysed. The aim of this study was to assess the possibilities of briquetting using commonly available laundry starch as a binder while evaluating the possible utilization of the waste gas originating from the thermal treatment of the briquettes. Briquettes (100g) were formed with the admixture of starch (UNIPRET) and their mechanical properties were analysed. Consequently, they were subjected to thermal treatment of 900, 1000 and 1100°C with retention period of 40min during which was the waste gas collected and its content analysed using gas chromatography. Dependency of the concentration of the compounds forming the waste gas on the temperature used was determined using Principal component analysis (PCA) and correlation matrix. Starch was found to be a very good binder and reduction agent, it was confirmed that metallic iron was formed during the thermal treatment. Approximately 20l of waste gas was obtained from the treatment of one briquette; main compounds were methane and hydrogen rendering the waste gas utilizable as a fuel while the greatest yield was during the lowest temperatures. Preparation of blast furnace sludge briquettes using starch as a binder and their thermal treatment represents a suitable method for recycling of this type of metallurgical waste. Moreover, the composition of the resulting gas is favourable for its use as a fuel. Copyright © 2015 Elsevier Ltd. All rights reserved.

Health Hazard Evaluation Report HETA 84-204-1600, Dental Health Associates, Paoli, Pennsylvania. [Nitrous oxide

Energy Technology Data Exchange (ETDEWEB)

Crandall, M.S.

1985-06-01

Area air and breathing-zone samples were analyzed for nitrous oxide at Dental Health Associates, Paoli, Pennsylvania on August 2, 1984. The evaluation was requested by a dental assistant because of general concern about the extent of nitrous oxide exposure, especially since the office was not equipped with a waste-anesthetic gas-scavenging system. The author recommends installing a waste anesthetic gas scavenging system with a dedicated exhaust. The nitrous oxide delivery and mixing system should be checked for leaks monthly and work practices for handling nitrous oxide should be improved.

Health Hazard Evaluation Report HETA 84-412-1612, Drs. Youdelman and Teig, Brentwood, New York. [Nitrous oxide

Energy Technology Data Exchange (ETDEWEB)

Crandall, M.S.

1985-07-01

Environmental and breathing zone samples were analyzed for nitrous-oxide (10102440) at two oral surgery clinics in Holbrook and Brentwood, New York on July 30 to 31, 1984. The evaluation was requested by the dentists because of general concern regarding the extent of exposure to nitrous oxide. The Brentwood office was equipped with a waste anesthetic gas scavenging system. Recommendations include checking the nitrous-oxide delivery and mixing systems at both clinics, installing a waste anesthetic gas scavenging system with a dedicated exhaust at the Holbrook office, and improving work practices at the Brentwood clinic.

A thermodynamic approach on vapor-condensation of corrosive salts from flue gas on boiler tubes in waste incinerators

International Nuclear Information System (INIS)

Otsuka, Nobuo

2008-01-01

Thermodynamic equilibrium calculation was conducted to understand the effects of tube wall temperature, flue gas temperature, and waste chemistry on the type and amount of vapor-condensed 'corrosive' salts from flue gas on superheater and waterwall tubes in waste incinerators. The amount of vapor-condensed compounds from flue gases at 650-950 deg. C on tube walls at 350-850 deg. C was calculated, upon combustion of 100 g waste with 1.6 stoichiometry (in terms of the air-fuel ratio). Flue gas temperature, rather than tube wall temperature, influenced the deposit chemistry of boiler tubes significantly. Chlorine, sulfur, sodium, potassium, and calcium contents in waste affected it as well

Gas retention and release behavior in Hanford double-shell waste tanks

Energy Technology Data Exchange (ETDEWEB)

Meyer, P.A.; Brewster, M.E.; Bryan, S.A. [and others

1997-05-01

This report describes the current understanding of flammable gas retention and release in Hanford double-shell waste tanks AN-103, AN-104, AN-105, AW-101, SY-101, and SY-103. This knowledge is based on analyses, experimental results, and observations of tank behavior. The applicable data available from the void fraction instrument, retained gas sampler, ball rheometer, tank characterization, and field monitoring are summarized. Retained gas volumes and void fractions are updated with these new data. Using the retained gas compositions from the retained gas sampler, peak dome pressures during a gas burn are calculated as a function of the fraction of retained gas hypothetically released instantaneously into the tank head space. Models and criteria are given for gas generation, initiation of buoyant displacement, and resulting gas release; and predictions are compared with observed tank behavior.

Gas retention and release behavior in Hanford double-shell waste tanks

International Nuclear Information System (INIS)

Meyer, P.A.; Brewster, M.E.; Bryan, S.A.

1997-05-01

This report describes the current understanding of flammable gas retention and release in Hanford double-shell waste tanks AN-103, AN-104, AN-105, AW-101, SY-101, and SY-103. This knowledge is based on analyses, experimental results, and observations of tank behavior. The applicable data available from the void fraction instrument, retained gas sampler, ball rheometer, tank characterization, and field monitoring are summarized. Retained gas volumes and void fractions are updated with these new data. Using the retained gas compositions from the retained gas sampler, peak dome pressures during a gas burn are calculated as a function of the fraction of retained gas hypothetically released instantaneously into the tank head space. Models and criteria are given for gas generation, initiation of buoyant displacement, and resulting gas release; and predictions are compared with observed tank behavior

Mechanisms of gas retention and release: Experimental results for Hanford waste tanks 241-AW-101 and 241-AN-103

Energy Technology Data Exchange (ETDEWEB)

Rassat, S.D.; Gauglitz, P.A.; Bredt, P.R.; Mahoney, L.A.; Forbes, S.V.; Tingey, S.M.

1997-09-01

The 177 storage tanks at Hanford contain a vast array of radioactive waste forms resulting, primarily, from nuclear materials processing. Through radiolytic, thermal, and other decomposition reactions of waste components, gaseous species including hydrogen, ammonia, and the oxidizer nitrous oxide are generated within the waste tanks. Many of these tanks are known to retain and periodically release quantities of these flammable gas mixtures. The primary focus of the Flammable Gas Project is the safe storage of Hanford tank wastes. To this end, we strive to develop an understanding of the mechanisms of flammable gas retention and release in Hanford tanks through laboratory investigations on actual tank wastes. These results support the closure of the Flammable Gas Unreviewed Safety Question (USQ) on the safe storage of waste tanks known to retain flammable gases and support resolution of the broader Flammable Gas Safety Issue. The overall purpose of this ongoing study is to develop a comprehensive and thorough understanding of the mechanisms of flammable gas retention and release. The first objective of the current study was to classify bubble retention and release mechanisms in two previously untested waste materials from Tanks 241-AN-103 (AN-103) and 241-AW-101 (AW-101). Results were obtained for retention mechanisms, release characteristics, and the maximum gas retention. In addition, unique behavior was also documented and compared with previously studied waste samples. The second objective was to lengthen the duration of the experiments to evaluate the role of slowing bubble growth on the retention and release behavior. Results were obtained for experiments lasting from a few hours to a few days.

Mechanisms of gas retention and release: Experimental results for Hanford waste tanks 241-AW-101 and 241-AN-103

International Nuclear Information System (INIS)

Rassat, S.D.; Gauglitz, P.A.; Bredt, P.R.; Mahoney, L.A.; Forbes, S.V.; Tingey, S.M.

1997-09-01

The 177 storage tanks at Hanford contain a vast array of radioactive waste forms resulting, primarily, from nuclear materials processing. Through radiolytic, thermal, and other decomposition reactions of waste components, gaseous species including hydrogen, ammonia, and the oxidizer nitrous oxide are generated within the waste tanks. Many of these tanks are known to retain and periodically release quantities of these flammable gas mixtures. The primary focus of the Flammable Gas Project is the safe storage of Hanford tank wastes. To this end, we strive to develop an understanding of the mechanisms of flammable gas retention and release in Hanford tanks through laboratory investigations on actual tank wastes. These results support the closure of the Flammable Gas Unreviewed Safety Question (USQ) on the safe storage of waste tanks known to retain flammable gases and support resolution of the broader Flammable Gas Safety Issue. The overall purpose of this ongoing study is to develop a comprehensive and thorough understanding of the mechanisms of flammable gas retention and release. The first objective of the current study was to classify bubble retention and release mechanisms in two previously untested waste materials from Tanks 241-AN-103 (AN-103) and 241-AW-101 (AW-101). Results were obtained for retention mechanisms, release characteristics, and the maximum gas retention. In addition, unique behavior was also documented and compared with previously studied waste samples. The second objective was to lengthen the duration of the experiments to evaluate the role of slowing bubble growth on the retention and release behavior. Results were obtained for experiments lasting from a few hours to a few days

Assessment of alternative disposal methods to reduce greenhouse gas emissions from municipal solid waste in India.

Science.gov (United States)

Yedla, Sudhakar; Sindhu, N T

2016-06-01

Open dumping, the most commonly practiced method of solid waste disposal in Indian cities, creates serious environment and economic challenges, and also contributes significantly to greenhouse gas emissions. The present article attempts to analyse and identify economically effective ways to reduce greenhouse gas emissions from municipal solid waste. The article looks at the selection of appropriate methods for the control of methane emissions. Multivariate functional models are presented, based on theoretical considerations as well as the field measurements to forecast the greenhouse gas mitigation potential for all the methodologies under consideration. Economic feasibility is tested by calculating the unit cost of waste disposal for the respective disposal process. The purpose-built landfill system proposed by Yedla and Parikh has shown promise in controlling greenhouse gas and saving land. However, these studies show that aerobic composting offers the optimal method, both in terms of controlling greenhouse gas emissions and reducing costs, mainly by requiring less land than other methods. © The Author(s) 2016.

A novel technique for finding gas bubbles in the nuclear waste containers using Muon Scattering Tomography

Science.gov (United States)

Dobrowolska, M.; Velthuis, J.; Frazão, L.; Kikoła, D.

2018-05-01

Nuclear waste is deposited for many years in the concrete or bitumen-filled containers. With time hydrogen gas is produced, which can accumulate in bubbles. These pockets of gas may result in bitumen overflowing out of the waste containers and could result in spread of radioactivity. Muon Scattering Tomography is a non-invasive scanning method developed to examine the unknown content of nuclear waste drums. Here we present a method which allows us to successfully detect bubbles larger than 2 litres and determine their size with a relative uncertainty resolution of 1.55 ± 0.77%. Furthermore, the method allows to make a distinction between a conglomeration of bubbles and a few smaller gas volumes in different locations.

Waste management - sewage - special wastes

International Nuclear Information System (INIS)

1987-01-01

The 27 papers represent a cross-section of the subject waste management. Particular attention is paid to the following themes: waste avoidance, waste product utilization, household wastes, dumping technology, sewage sludge treatments, special wastes, seepage from hazardous waste dumps, radioactive wastes, hospital wastes, purification of flue gas from waste combustion plants, flue gas purification and heavy metals, as well as combined sewage sludge and waste product utilization. The examples given relate to plants in Germany and other European countries. 12 papers have been separately recorded in the data base. (DG) [de

Microbial Gas Generation Under Expected Waste Isolation Pilot Plant Repository Conditions: Final Report

Energy Technology Data Exchange (ETDEWEB)

Gillow, J.B.; Francis, A.

2011-07-01

Gas generation from the microbial degradation of the organic constituents of transuranic (TRU) waste under conditions expected in the Waste Isolation Pilot Plant (WIPP) was investigated. The biodegradation of mixed cellulosic materials and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, hypalon, leaded hypalon, and neoprene) was examined. We evaluated the effects of environmental variables such as initial atmosphere (air or nitrogen), water content (humid ({approx}70% relative humidity, RH) and brine inundated), and nutrient amendments (nitogen phosphate, yeast extract, and excess nitrate) on microbial gas generation. Total gas production was determined by pressure measurement and carbon dioxide (CO{sub 2}) and methane (CH{sub 4}) were analyzed by gas chromatography; cellulose degradation products in solution were analyzed by high-performance liquid chromatography. Microbial populations in the samples were determined by direct microscopy and molecular analysis. The results of this work are summarized.

Operational improvement to the flue gas cleaning system in radioactive waste incineration facilities

International Nuclear Information System (INIS)

Zheng Bowen; Li Xiaohai; Wang Peiyi

2012-01-01

After years of operation, some problems, such as corrosion and waste water treatment, have been found in the first domestic whole-scale radioactive waste incineration facility. According to the origin of the problems, the flue gas cleaning system has been optimized and improved in terms of technical process, material and structure. It improves the operational stability, extends the equipment life-time, and also reduces the amount of secondary waste. In addition, as major sources of problems, waste management, operational experiences and information exchange deserve more attention. (authors)

Gas production, composition and emission at a modern disposal site receiving waste with a low-organic content

DEFF Research Database (Denmark)

Scheutz, Charlotte; Fredenslund, Anders Michael; Nedenskov, Jonas

2011-01-01

AV Miljø is a modern waste disposal site receiving non-combustible waste with a low-organic content. The objective of the current project was to determine the gas generation, composition, emission, and oxidation in top covers on selected waste cells as well as the total methane (CH4) emission from....... The results indicated that the gas composition in the shredder waste was governed by chemical reactions as well as microbial reactions. CH4 mass balances from three individual waste cells showed that a significant part (between 15% and 67%) of the CH4 generated in cell 1.3 and 2.2.2 was emitted through...

Landfill gas from solid urban waste - an opportunity evaluation

International Nuclear Information System (INIS)

Gramatikov, Plamen; Kovachev, Vassil; Gramatikova, Marija

2004-01-01

The problems (technical, economic, social etc.) which have to be solved by municipal waste treatment, especially in Central/East European towns, are discussed in this work. Percentages of products and calorific values of the main solid organic wastes are estimated. Different urban waste utilisation methods - Landfills Anaerobic digestion, Incineration, Refuse-derived fuels, Pyrolysis and Gasification are comment in this paper. These methods are compared using the town of Blagoevgrad (Bulgaria) as an example. It is round that a well established landfill gas production technology offers simplicity of collection (such as is practised in most of low and moderately developed countries like Bulgaria), relatively simple operation and maintenance, improvement of the environmental protection and of the energy production (based on the local disposal and renewable energy sources) and is more feasible for the East European urban concentrations. (Author)

Waste management and climate protection. Contribution of Bavarian waste management for greenhouse gas minimization; Abfallwirtschaft und Klimaschutz. Beitrag der bayerischen Abfallwirtschaft zur Treibhausgas-Minderung

Energy Technology Data Exchange (ETDEWEB)

Peche, R.; Kreibe, S. [bifa Umweltinstitut, Augsburg (Germany)

2007-08-15

bifa created a material flow model for approximately 23 million tons of Bavarian municipal and industrial waste that incorporates collection of waste, waste disposal and processing and treatment of residual material. bifa determined the influence of these material flows on emissions of greenhouse gases. The analysis shows that the Bavarian waste management achieved a reduction of greenhouse gases in the municipal and industrial waste sector that amounted to 3.2 million tons of carbon dioxide equivalents (CO{sub 2}E) in 2003, thus reducing environmental impact considerably. To see the overall reduction of greenhouse gases it is however necessary to compare the system of waste collection, waste treatment and waste processing with a fictitious scenario of waste disposal exclusively via landfill. This would cause an environmental load of 9.58 million tons CO{sub 2}E. Together with the amount of reduction attained in 2003, an overall reduction of greenhouse gas emissions of 12.78 millions tons CO{sub 2}E has thus been achieved by the Bavarian waste management. Analysis of possible future waste processing and waste avoidance measures showed two areas with significant additional potential for the reduction of greenhouse gas emissions. One is waste avoidance - e. g. through increased municipal counselling - however, this is difficult to realize. The other possibility is the optimisation of bio-waste processing. (orig.)

Reduction of energy cost and CO{sub 2} emission for the furnace using energy recovered from waste tail-gas

Energy Technology Data Exchange (ETDEWEB)

Jou, Chih-Ju G.; Wu, Chung-Rung; Lee, Chien-Li [Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, No. 2, Jhuoyue Road, Nanzih District, Kaohsiung 811 (China)

2010-03-15

In this research, the waste tail gas emitted from petrochemical processes, e.g. catalytic reforming unit, catalytic cracking unit and residue desulfurization unit, was recovered and reused as a replacement of natural gas (NG). On-site experimental results show that both the flame length and orange-yellowish brightness decrease with more proportion of waste gas fuel added to the natural gas, and that the adiabatic temperature of the mixed fuel is greater than 1800 C. A complete replacement of natural gas by the recovered waste gas fuel will save 5.8 x 10{sup 6} m{sup 3} of natural gas consumption, and 3.5 x 10{sup 4} tons of CO{sub 2} emission annually. In addition, the reduction of residual O{sub 2} concentration in flue gases from 4% to 3% will save 1.1 x 10{sup 6} m{sup 3} of natural gas consumption, reduce 43.0% of NO{sub x} emission, and 1.3 x 10{sup 3} tons of CO{sub 2} emission annually. Thus, from the viewpoint of the overall economics and sustainable energy policy, recovering the waste tail gas energy as an independent fuel source to replace natural gas is of great importance for saving energy, reducing CO{sub 2} emission reduction, and lowering environmental impact. (author)

The potential for buoyant displacement gas release events in Tank 241-SY-102 after waste transfer from Tank 241-SY-101

International Nuclear Information System (INIS)

Wells, BE; Meyer, P.E.; Chen, G.

2000-01-01

Tank 241-SY-101 (SY-101) is a double-shell, radioactive waste storage tank with waste that, before the recent transfer and water back-dilution operations, was capable of retaining gas and producing buoyant displacement (BD) gas release events (GREs). Some BD GREs caused gas concentrations in the tank headspace to exceed the lower flammability limit (LFL). A BD GRE occurs when a portion of the nonconvective layer retains enough gas to become buoyant, rises to the waste surface, breaks up, and releases some of its stored gas. The installation of a mixer pump in 1993 successfully mitigated gas retention in the settled solids layer in SY-101 and has since prevented BD GREs. However, operation of the mixer pump over the years caused gas retention in the floating crust layer and a corresponding accelerated waste level growth. The accelerating crust growth trend observed in 1997--98 led to initiation of sequences of waste removal and water back-dilutions in December 1999. Waste is removed from the mixed slurry layer in Tank SY-101 and transferred into Tank 241-Sy-102 (SY-102). Water is then added back to dissolve soluble solids that retain gas. The initial transfer of 89,500 gallons of SY-101 waste, diluted in-line at 0.94:1 by volume with water, to SY-102 was conducted in December 1999. The second transfer of 230,000 gallons of original SY-101 waste, diluted approximately 0.9:1, was completed in January 2000, and the third transfer of 205,500 gallons of original SY-101 waste diluted at 0.9:1 was completed in March 2000

DOE mixed waste metals partition in a rotary kiln wet off-gas system

International Nuclear Information System (INIS)

Burns, D.B.; Looper, M.G.

1994-01-01

In 1996, the Savannah River Site plans to begin operation of the Consolidated Incineration Facility (CIF) to treat solid and liquid RCRA hazardous and mixed wastes. Test burns were conducted using surrogate CIF wastes spiked with hazardous metals and organics. The partition of metals between the kiln bottom ash, scrubber blowdown solution, and stack gas was measured as a function of kiln temperature, waste chloride content, and waste form (liquid or solid). Three waste simulants were used in these tests, a high and low chloride solid waste mix (paper, plastic, latex, PVC), and a liquid waste mix (benzene and chlorobenzene). An aqueous solution containing: antimony, arsenic, barium, cadmium, chromium, lead, mercury, nickel, silver, and thallium was added to the waste to determine metals fate under various combustion conditions. Test results were used to divide the metals into three general groups, volatile, semi-volatile, and nonvolatile metals. Mercury was the only volatile metal. No mercury remained in the kiln bottom ash under any incineration condition. Lead, cadmium, thallium, and silver exhibited semi-volatile behavior. The partition between the kiln ash, blowdown, and stack gas depended on incineration conditions. Chromium, nickel, barium, antimony, and arsenic exhibited nonvolatile behavior, with greater than 90 wt % of the metal remaining in the kiln bottom ash. Incineration temperature had a significant effect on the partition of volatile and semi-volatile metals, and no effect on nonvolatile metal partition. As incineration temperatures were increased, the fraction of metal leaving the kiln increased. Three metals, lead, cadmium, and mercury showed a relationship between chloride concentration in the waste and metals partition. Increasing the concentration of chlorides in the waste or burning liquid waste versus solid waste resulted in a larger fraction of metal exiting the kiln

Assessment of potential greenhouse gas mitigation of available household solid waste treatment technologies

Directory of Open Access Journals (Sweden)

Hoang Minh Giang

2013-11-01

Full Text Available Current household solid waste treatment practices in most cities in Vietnam caused a great amount of direct greenhouse gas (GHG emissions. Available solid waste treatment technologies should be seriously taken  into consideration as a wedge of GHG mitigation in waste sector base on presently Vietnamese economic conditions. This study aim to evaluate the potential amount of GHG mitigation from current domestic solid waste treatment technologies in Vietnam including landfills and composting from various management scenarios. In oder to use Tier 2 model of IPCC 2006 for GHG estimation from landfills, an analysis on current household solid waste management system of the city was obtained by using material flow analysis approach. A case study in Hanoi, the capital city of Vietnam was carried out in this research. As a result, there was a reduced of over 70% of the amount of CH4 emissions and  up to 53% of total GHG saving (CO2-eq from avoiding organic waste to landfill. In addition, applying an energy recovery from LFG system to available landfills would lead to aproximately 75% of GHG saved compare to current emission of waste sector.Doi: http://dx.doi.org/10.12777/wastech.1.1.10-16Citation: Giang, H.M.,Luong, N.D., and Huong, L.T.M.2013. Assessment of potential greenhouse gas mitigation of available household solid waste treatment technologies. . Waste Technology 1(1:6-9. Doi: http://dx.doi.org/10.12777/wastech.1.1.10-16

Cogeneration from Poultry Industry Wastes -- Part I: Indirectly Fired Gas Turbine Application

DEFF Research Database (Denmark)

Peretto, A.; Bianchi, M.; Cherubini, F.

2003-01-01

The availability of wet biomass as waste from a agriculture and farms and the need to meet the environmental standards force to investigate all options in order to dispose this waste. The possible treatments usually strongly depend on the biomass characteristics, namely water content, density....... Different plant configurations have been considered in order to make use of the oil and of the meat and bone meal, which are the by-products of the chicken cooking process. In particular, the process plant can be integrated with an energy supply plant which can consist of a Indirectly Fired Gas Turbine....../production and of return of the investments (Part II). Keywords: biomass, cogeneration, Gas Turbine, IFGT...

Off-Gas Analysis During the Vitrification of Hanford Radioactive Waste Samples

International Nuclear Information System (INIS)

Ha, B.C.; Ferrara, D.M.; Crawford, C.L.; Choi, A.S.; Bibler, N.E.

1998-01-01

This paper describes the off-gas analysis of samples collected during the radioactive vitrification experiments. Production and characterization of the Hanford waste-containing LAW and HAW glasses are presented in related reports from this conference

Well-to-Wheels Analysis of Compressed Natural Gas and Ethanol from Municipal Solid Waste

Energy Technology Data Exchange (ETDEWEB)

Lee, Uisung [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Wang, Michael [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

2016-10-01

The amount of municipal solid waste (MSW) generated in the United States was estimated at 254 million wet tons in 2013, and around half of that generated waste was landfilled. There is a huge potential in recovering energy from that waste, since around 60% of landfilled material is biomass-derived waste that has high energy content. In addition, diverting waste for fuel production avoids huge fugitive emissions from landfills, especially uncontrolled CH₄ emissions, which are the third largest anthropogenic CH₄ source in the United States. Lifecycle analysis (LCA) is typically used to evaluate the environmental impact of alternative fuel production pathways. LCA of transportation fuels is called well-to-wheels (WTW) and covers all stages of the fuel production pathways, from feedstock recovery (well) to vehicle operation (wheels). In this study, the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET^®) model developed by Argonne National Laboratory is used to evaluate WTW greenhouse gas (GHG) emissions and fossil fuel consumption of waste-derived fuels. Two waste-to-energy (WTE) pathways have been evaluated – one for compressed natural gas (CNG) production using food waste via anaerobic digestion, and the other for ethanol production from yard trimmings via fermentation processes. Because the fuel production pathways displace current waste management practices (i.e., landfilling waste), we use a marginal approach that considers only the differences in emissions between the counterfactual case and the alternative fuel production case.

General anesthetics in children: neurotoxic or neuroprotective?

Directory of Open Access Journals (Sweden)

Jéssica Farias Rebouças

2017-02-01

Full Text Available Introduction: general anesthetics are involved in neuroprotection in adults after ischemic events and cognitive impairment, thus, they also may be associated with learning disorders in children exposed to them before three years of age. Objective: Describe about the neurotoxic effects of general anesthetics in experimental animals and children. Method: This is a systematic review, performed from search in databases and on PubMed using the keywords "neurotoxicity" and "general anesthetics," and "general anesthetics," "neurotoxicity", "children", "young child "and" pediatric ". Results: The search resulted in 185 articles. Out of these, 78 met our inclusion criteria. We found that there was a significant evidence of neurotoxicity induced by general anesthetics in experimental animals that were just born, resulting in late and permanent cognitive deficits. This effect was associated with multiple exposures, exposure length of time and combination of drugs. However, some studies found cognitive impairment after a single exposure to anesthetic. Conclusion: There is insufficient evidence to state that general anesthetics are neurotoxic and have the potential to trigger learning and behavior disabilities in children. However, we suggest caution in indicating surgery in children under three years old, analyzing risk-benefit and inserting the family in the decision process.   Keywords: Neurotoxicity; Neuroprotection; Cognitive Impairment; Children; General Anesthesics

Bench scale experiments for the remediation of Hanford Waste Treatment Plant low activity waste melter off-gas condensate

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, Kathryn M.L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, Michael [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2017-08-11

The Low Activity Waste (LAW) vitrification facility at the Hanford Waste Treatment and Immobilization Plant (WTP) will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The plan for disposition of this stream during baseline operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. The primary reason to recycle this stream is so that the semi-volatile 99Tc isotope eventually becomes incorporated into the glass. This stream also contains non-radioactive salt components that are problematic in the melter, so diversion of this stream to another process would eliminate recycling of these salts and would enable simplified operation of the LAW melter and the Pretreatment Facilities. This diversion from recycling this stream within WTP would have the effect of decreasing the LAW vitrification mission duration and quantity of glass waste. The concept being tested here involves removing the ⁹⁹Tc so that the decontaminated aqueous stream, with the problematic salts, can be disposed elsewhere.

Analysis the potential gas production of old municipal solid waste landfill as an alternative energy source: Preliminary results

Science.gov (United States)

Hayati, A. P.; Emalya, N.; Munawar, E.; Schwarzböck, T.; Lederer, J.; Fellner, J.

2018-03-01

The MSW landfill produces gas which is represent the energy resource that lost and polluted the ambient air. The objective of this study is to evaluate the potential gas production of old landfill as an alternative energy source. The study was conducted by using 10 years old waste in landfill simulator reactor (LSR). Four Landfills Simulator Reactors (LSR) were constructed for evaluate the gas production of old MSW landfilled. The LSR was made of high density poly ethylene (HDPE) has 50 cm outside diameter and 150 cm of high. The 10 years old waste was excavated from closed landfill and subsequently separated from inorganic fraction and sieved to maximum 50 mm size particle prior emplaced into the LSR. Although quite small compare to the LSR containing fresh waste has been reported, the LRS containing 10 years old waste still produce much landfill gas. The landfill gas produced of LSR operated with and without leachate recirculation were about 29 and 21 litter. The composition of landfill gas produced was dominated by CO2 with the composition of CH4 and O2 were around 12.5% and 0.2 %, respectively.

On the thermodynamics of waste heat recovery from internal combustion engine exhaust gas

Science.gov (United States)

Meisner, G. P.

2013-03-01

The ideal internal combustion (IC) engine (Otto Cycle) efficiency ηIC = 1-(1/r)(γ - 1) is only a function of engine compression ratio r =Vmax/Vmin and exhaust gas specific heat ratio γ = cP/cV. Typically r = 8, γ = 1.4, and ηIC = 56%. Unlike the Carnot Cycle where ηCarnot = 1-(TC/TH) for a heat engine operating between hot and cold heat reservoirs at TH and TC, respectively, ηIC is not a function of the exhaust gas temperature. Instead, the exhaust gas temperature depends only on the intake gas temperature (ambient), r, γ, cV, and the combustion energy. The ejected exhaust gas heat is thermally decoupled from the IC engine and conveyed via the exhaust system (manifold, pipe, muffler, etc.) to ambient, and the exhaust system is simply a heat engine that does no useful work. The maximum fraction of fuel energy that can be extracted from the exhaust gas stream as useful work is (1-ηIC) × ηCarnot = 32% for TH = 850 K (exhaust) and TC = 370 K (coolant). This waste heat can be recovered using a heat engine such as a thermoelectric generator (TEG) with ηTEG> 0 in the exhaust system. A combined IC engine and TEG system can generate net useful work from the exhaust gas waste heat with efficiency ηWH = (1-ηIC) × ηCarnot ×ηTEG , and this will increase the overall fuel efficiency of the total system. Recent improvements in TEGs yield ηTEG values approaching 15% giving a potential total waste heat conversion efficiency of ηWH = 4.6%, which translates into a fuel economy improvement approaching 5%. This work is supported by the US DOE under DE-EE0005432.

Treatment of waste using a hybrid gas- water stabilized torch

Czech Academy of Sciences Publication Activity Database

Van Oost, G.; Hrabovský, Milan; Kopecký, Vladimír; Konrád, Miloš; Hlína, Michal; Kavka, Tetyana; Beeckman, E.; Verstraeten, J.

2005-01-01

Roč. 5, č. 1 (2005), s. 7-12. ISBN 4-9900642-4-8 R&D Projects: GA ČR GA202/05/0669 Institutional research plan: CEZ:AV0Z20430508 Keywords : Thermal plasma * pyrolysis * waste treatment Subject RIV: BL - Plasma and Gas Discharge Physics

Mechanisms of gas retention and release: Experimental results for Hanford single-shell waste tanks 241-A-101, 241-S-106, and 241-U-103

International Nuclear Information System (INIS)

Rassat, S.D.; Caley, S.M.; Bredt, P.R.; Gauglitz, P.A.; Rinehart, D.E.; Forbes, S.V.

1998-09-01

The 177 underground waste storage tanks at the Hanford Site contain millions of gallons of radioactive waste resulting from the purification of nuclear materials and related processes. Through various mechanisms, flammable gas mixtures of hydrogen, ammonia, methane, and nitrous oxide are generated and retained in significant quantities within the waste in many (∼25) of these tanks. The potential for large releases of retained gas from these wastes creates a flammability hazard. It is a critical component of the effort to understand the flammability hazard and a primary goal of this laboratory investigation to establish an understanding of the mechanisms of gas retention and release in these wastes. The results of bubble retention experimental studies using waste samples from several waste tanks and a variety of waste types support resolution of the Flammable Gas Safety Issue. Gas bubble retention information gained in the pursuit of safe storage will, in turn, benefit future waste operations including salt-well pumping, waste transfers, and sluicing/retrieval

Atmospheric Pressure Effect of Retained Gas in High Level Waste

International Nuclear Information System (INIS)

Weber, A.H.

1999-01-01

Isolated high level waste tanks in H-Area have unexplained changes in waste-level which have been attributed to environmental effects including pressure, temperature, and relative humidity. Previous studies at SRS have considered waste-level changes from causes not including the presence of gas in the salt cake. This study was undertaken to determine the effect of atmospheric pressure on gas in the salt cake and resultant changes in the supernate level of Tank 41H, and to model that effect if possible. A simple theory has been developed to account for changes in the supernate level in a high level waste tank containing damp salt cake as the response of trapped gases to changes in the ambient pressure. The gas is modeled as an ideal gas retained as bubbles within the interstitial spaces in the salt cake and distributed uniformly throughout the tank. The model does not account for consistent long term increases or decreases in the tank level. Any such trend in the tank level is attributed to changes in the liquid content in the tank (from condensation, evaporation, etc.) and is removed from the data prior to the void estimation. Short term fluctuations in the tank level are explained as the response of the entrained gas volume to changes in the ambient pressure. The model uses the response of the tank level to pressure changes to estimate an average void fraction for the time period of interest. This estimate of the void is then used to predict the expected level response. The theory was applied to three separate time periods of the level data for tank 41H as follows: (1) May 3, 1993 through August 3, 1993, (2) January 23, 1994 through April 21, 1994, and (3) June 4, 1994 through August 24, 1994. A strong correlation was found between fluctuations in the tank level and variations in the ambient pressure. This correlation is a clear marker of the presence of entrained gases in the tank. From model calculations, an average void fraction of 11 percent was estimated to

TRU Waste Sampling Program: Volume I. Waste characterization

International Nuclear Information System (INIS)

Clements, T.L. Jr.; Kudera, D.E.

1985-09-01

Volume I of the TRU Waste Sampling Program report presents the waste characterization information obtained from sampling and characterizing various aged transuranic waste retrieved from storage at the Idaho National Engineering Laboratory and the Los Alamos National Laboratory. The data contained in this report include the results of gas sampling and gas generation, radiographic examinations, waste visual examination results, and waste compliance with the Waste Isolation Pilot Plant-Waste Acceptance Criteria (WIPP-WAC). A separate report, Volume II, contains data from the gas generation studies

Evaluation of Gas Retention in Waste Simulants: Intermediate-Scale Column and Open-Channel-Depth Tests

Energy Technology Data Exchange (ETDEWEB)

Powell, Michael R.; Gauglitz, Phillip A.; Denslow, Kayte M.; Fischer, Christopher M.; Heldebrant, David J.; Prowant, Matthew S.; Sande, Susan; Davis, James M.; Telander, Monty R.

2014-02-14

Gas generation in Hanford’s radioactive waste storage tanks can lead to gas accumulation within the layer of settled solids (sludge) at the tank bottom. The gas, which may be hazardous and/or flammable, is formed principally by radiation-driven chemical reactions. Accumulation of these gases within the sludge increases the sludge-layer volume, which decreases the available tank volume for waste storage. Further, accumulation of large amounts of gas in the sludge can potentially result in a relatively rapid release of the accumulated gas if the sludge-layer density is reduced to less than that of the overlying sludge or that of the supernatant liquid. The potential for rapid release of large amounts of hazardous and/or flammable gases is a safety hazard that needs to be managed. Accordingly, a thorough understanding is needed of the circumstances that can lead to problematic gas accumulation in sludge layers. The Deep-Sludge Gas Release Event Project (DSGREP) is tasked with developing an improved understanding of these gas release events.

Equipment design guidance document for flammable gas waste storage tank new equipment

International Nuclear Information System (INIS)

Smet, D.B.

1996-01-01

This document is intended to be used as guidance for design engineers who are involved in design of new equipment slated for use in Flammable Gas Waste Storage Tanks. The purpose of this document is to provide design guidance for all new equipment intended for application into those Hanford storage tanks in which flammable gas controls are required to be addressed as part of the equipment design. These design criteria are to be used as guidance. The design of each specific piece of new equipment shall be required, as a minimum to be reviewed by qualified Unreviewed Safety Question evaluators as an integral part of the final design approval. Further Safety Assessment may be also needed. This guidance is intended to be used in conjunction with the Operating Specifications Documents (OSDs) established for defining work controls in the waste storage tanks. The criteria set forth should be reviewed for applicability if the equipment will be required to operate in locations containing unacceptable concentrations of flammable gas

Uncertainty and sensitivity analyses for gas and brine migration at the Waste Isolation Pilot Plant, May 1992

International Nuclear Information System (INIS)

Helton, J.C.; Bean, J.E.; Butcher, B.M.; Garner, J.W.; Vaughn, P.; Schreiber, J.D.; Swift, P.N.

1993-08-01

Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis, stepwise regression analysis and examination of scatterplots are used in conjunction with the BRAGFLO model to examine two phase flow (i.e., gas and brine) at the Waste Isolation Pilot Plant (WIPP), which is being developed by the US Department of Energy as a disposal facility for transuranic waste. The analyses consider either a single waste panel or the entire repository in conjunction with the following cases: (1) fully consolidated shaft, (2) system of shaft seals with panel seals, and (3) single shaft seal without panel seals. The purpose of this analysis is to develop insights on factors that are potentially important in showing compliance with applicable regulations of the US Environmental Protection Agency (i.e., 40 CFR 191, Subpart B; 40 CFR 268). The primary topics investigated are (1) gas production due to corrosion of steel, (2) gas production due to microbial degradation of cellulosics, (3) gas migration into anhydrite marker beds in the Salado Formation, (4) gas migration through a system of shaft seals to overlying strata, and (5) gas migration through a single shaft seal to overlying strata. Important variables identified in the analyses include initial brine saturation of the waste, stoichiometric terms for corrosion of steel and microbial degradation of cellulosics, gas barrier pressure in the anhydrite marker beds, shaft seal permeability, and panel seal permeability

Mechanisms and modelling of gas migration from deep radioactive waste repositories

International Nuclear Information System (INIS)

Rodwell, W.R.; Nash, P.J.

1992-06-01

This report discusses the mechanisms by which gas is able to migrate through the far-field. The mechanisms available are diffusion or advection of gas dissolved in groundwater or free gas phase flow as either bubbles or a continuous stream of gas. Modelling approaches adopted to assess the migration are (a) simple use of Darcy's law with an effective permeability to gas, (b) the development of a model based on the representation of the far-field rock as a bundle of capillaries with a suitable distribution of radii, and (c) the use of a numerical model of two-phase flow in porous media. Finally, surveys have been carried out of published work on gas escape from underground storage caverns and of literature relating to gas movement from underground hydrocarbon accumulations to determine whether these may be potential sources of data or understanding of underground gas migration relevant to that from deep waste repositories. (author)

Assessment of waste management options in the oil and gas industry in Ghana using nuclear analytical techniques

International Nuclear Information System (INIS)

Ahialey, W. K.

2013-07-01

Ghana's oil find is growing steadily as more discoveries are being made. Oil and gas exploration and production coupled with their related activities produce wastes. These wastes could be put into three primary categories such as produced water, drilling cuttings and associated wastes (any other waste related with the exploration, development and production of crude oil or natural gas). These wastes may contain varying amount of contaminants such as heavy metals, suspended solid particles and radioactive materials such as Ra-226 or Rn-228, product of U-238 decay that occur in some geologic formations and sediments. The main objective of this study is to assess the waste management practices in the oil and gas industry in Ghana by qualification and quantification of waste generated during exploration and production, examining the system put in place by oil and gas companies to manage these wastes and also determine some basic contaminants in some of these wastes brought to shore for management. Waste samples were taken from Tema Oil Refinery (TOR) and Zeal Environmental Technology Limited at Takoradi. The samples were analyzed by Neutron Activation Analysis (NAA) and Flame Atomic Absorption Spectrometry (FAAS) analytical methods to determine heavy metals (Pb, Cd, Cr, Hg, As, Ag, Ba, Se) in the oily waste water, oil based mud, block and ash samples. The results showed that the levels of heavy metals were below the EPA permissible limit for discharge into the natural drainage except the level of Pb in the mud samples taken from Zeal before treatment. The levels ranged from 3.99mg/l to 7.44mgl. Even though these levels were above 0.1mg/l discharge standard limit, there was no cause for alarm because the levels dropped below the EPA limit after treatment. Furthermore, the quantity of general garbage deposited in the landfill at Takoradi be Zeal Environmental Technology Limited from 2011 to 2012 increased from 497m 3 to 1,314.29m 3 respectively. (author)

Position for determining gas-phase volatile organic compound concentrations in transuranic waste containers. Revision 2

Energy Technology Data Exchange (ETDEWEB)

Connolly, M.J.; Liekhus, K.J. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R. [Benchmark Environmental Corp. (United States)

1998-06-01

In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations.

Position for determining gas phase volatile organic compound concentrations in transuranic waste containers. Revision 1

International Nuclear Information System (INIS)

Connolly, M.J.; Liekhus, K.J.; Djordjevic, S.M.; Loehr, C.A.; Spangler, L.R.

1995-08-01

In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering Laboratory (INEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations

Position for determining gas-phase volatile organic compound concentrations in transuranic waste containers. Revision 2

International Nuclear Information System (INIS)

Connolly, M.J.; Liekhus, K.J.

1998-06-01

In the conditional no-migration determination (NMD) for the test phase of the Waste Isolation Pilot Plant (WIPP), the US Environmental Protection Agency (EPA) imposed certain conditions on the US Department of Energy (DOE) regarding gas phase volatile organic compound (VOC) concentrations in the void space of transuranic (TRU) waste containers. Specifically, the EPA required the DOE to ensure that each waste container has no layer of confinement that contains flammable mixtures of gases or mixtures of gases that could become flammable when mixed with air. The EPA also required that sampling of the headspace of waste containers outside inner layers of confinement be representative of the entire void space of the container. The EPA stated that all layers of confinement in a container would have to be sampled until DOE can demonstrate to the EPA that sampling of all layers is either unnecessary or can be safely reduced. A test program was conducted at the Idaho National Engineering and Environmental Laboratory (INEEL) to demonstrate that the gas phase VOC concentration in the void space of each layer of confinement in vented drums can be estimated from measured drum headspace using a theoretical transport model and that sampling of each layer of confinement is unnecessary. This report summarizes the studies performed in the INEEL test program and extends them for the purpose of developing a methodology for determining gas phase VOC concentrations in both vented and unvented TRU waste containers. The methodology specifies conditions under which waste drum headspace gases can be said to be representative of drum gases as a whole and describes a method for predicting drum concentrations in situations where the headspace concentration is not representative. The methodology addresses the approach for determining the drum VOC gas content for two purposes: operational period drum handling and operational period no-migration calculations

Waste Isolation Pilot Plant: Alcove Gas Barrier trade-off study

International Nuclear Information System (INIS)

Lin, M.S.; Van Sambeek, L.L.

1992-07-01

A modified Kepner-Tregoe method was used for a trade-off study of Alcove Gas Barrier (AGB) concepts for the Waste Isolation Pilot Plant. The AGB is a gas-constraining seal to be constructed in an alcove entrance drift. In this trade-off study, evaluation criteria were first selected. Then these criteria were classified as to their importance to the task, assigning a weighting value to each aspect. Eleven conceptual design alternatives were developed based on geometrical/geological considerations, construction materials, constructibility, and other relevant factors and evaluated

Interaction of Local Anesthetics with Biomembranes Consisting of Phospholipids and Cholesterol: Mechanistic and Clinical Implications for Anesthetic and Cardiotoxic Effects

Directory of Open Access Journals (Sweden)

Hironori Tsuchiya

2013-01-01

Full Text Available Despite a long history in medical and dental application, the molecular mechanism and precise site of action are still arguable for local anesthetics. Their effects are considered to be induced by acting on functional proteins, on membrane lipids, or on both. Local anesthetics primarily interact with sodium channels embedded in cell membranes to reduce the excitability of nerve cells and cardiomyocytes or produce a malfunction of the cardiovascular system. However, the membrane protein-interacting theory cannot explain all of the pharmacological and toxicological features of local anesthetics. The administered drug molecules must diffuse through the lipid barriers of nerve sheaths and penetrate into or across the lipid bilayers of cell membranes to reach the acting site on transmembrane proteins. Amphiphilic local anesthetics interact hydrophobically and electrostatically with lipid bilayers and modify their physicochemical property, with the direct inhibition of membrane functions, and with the resultant alteration of the membrane lipid environments surrounding transmembrane proteins and the subsequent protein conformational change, leading to the inhibition of channel functions. We review recent studies on the interaction of local anesthetics with biomembranes consisting of phospholipids and cholesterol. Understanding the membrane interactivity of local anesthetics would provide novel insights into their anesthetic and cardiotoxic effects.

Study on the correlation between volatile fatty acids and gas production in dry fermentation of kitchen waste

Science.gov (United States)

Li, Qiangqiang; Ma, Yunfeng; Du, Boying; Wang, Qi; Hu, Qiongqiong; Bian, Yushan

2018-02-01

In this study, continuous kitchen waste fermentation and anaerobic digestion experiments were conducted to analyze the gas production potential, and to study the correlation between gas production rate and volatile fatty acid (VFAs) and its component concentration. During the experiment, the total solid(TS) concentration of the reaction system was increased by adding the kitchen waste, analysis of kitchen waste dry fermentation process to start, run, imbalance and imbalance after recovery and the parameters in the process of realizing the change trend and influencing factors of dry fermentation process, pH and ammonia concentration.

Sensitivity Analysis of Population in The Generation of Hazardous and Non-Harzardous Wastes, and Gas from Dumpsites of Ogbomosoland in Nigeria

Directory of Open Access Journals (Sweden)

Samson O. Ojoawo

2013-01-01

Full Text Available This paper applies the principles of system dynamics modeling in studying the pattern of population changes and the corresponding non-hazardous wastes and gas being generated from the dumpsites of Ogbomosoland, Nigeria. The five (5 Local government Areas (LGAs of Ogbomosoland were categorized as Urban (Ogbomoso North and Ogbomoso South and Rural (Oriire, Ogo Oluwa and Suurulere based on the size, population of residents, consumption pattern and socio-economic activities of the area. A sensitivity analysis of the simulated variables i.e the population, wastes and gas, was performed by employing the developed model results. Findings showed that the wastes and gas increased with the increased population in the 1000 years period. Also, gas production exceeds wastes generation rates for the rural LGAs in all cases. After a 25 years benchmark, when the simulated population of the urban and rural LGAs are respectively 303,411 and 344,735, the rates of waste generation are 3.33x106 and 6.22 x106 m 3 , while the corresponding rates of gas production is 2.44x103 and 6.47x103 m 3 in same order. The study concludes that wastes and gas generation from dumpsites are highly sensitive to population growth. It also concluded that the rate of gas generation is higher in organic wastes of the rural LGAs. The maximum population permissible in the model is 300,000 thus design of full-fledge landfills is recommended to replace the existing dumpsites in the study area.

Anesthetic equipment, facilities and services available for pediatric ...

African Journals Online (AJOL)

2011-04-09

Apr 9, 2011 ... standards and increased use of disposable anesthetic equipment. An audit of equipment and facilities for anesthetic care in pediatric patients is important and should be carried out periodically to appraise the situation for upgrading of essential anesthetic facilities and equipment. Appendix A. 18th March, ...

Neural network models for biological waste-gas treatment systems.

Science.gov (United States)

Rene, Eldon R; Estefanía López, M; Veiga, María C; Kennes, Christian

2011-12-15

This paper outlines the procedure for developing artificial neural network (ANN) based models for three bioreactor configurations used for waste-gas treatment. The three bioreactor configurations chosen for this modelling work were: biofilter (BF), continuous stirred tank bioreactor (CSTB) and monolith bioreactor (MB). Using styrene as the model pollutant, this paper also serves as a general database of information pertaining to the bioreactor operation and important factors affecting gas-phase styrene removal in these biological systems. Biological waste-gas treatment systems are considered to be both advantageous and economically effective in treating a stream of polluted air containing low to moderate concentrations of the target contaminant, over a rather wide range of gas-flow rates. The bioreactors were inoculated with the fungus Sporothrix variecibatus, and their performances were evaluated at different empty bed residence times (EBRT), and at different inlet styrene concentrations (C(i)). The experimental data from these bioreactors were modelled to predict the bioreactors performance in terms of their removal efficiency (RE, %), by adequate training and testing of a three-layered back propagation neural network (input layer-hidden layer-output layer). Two models (BIOF1 and BIOF2) were developed for the BF with different combinations of easily measurable BF parameters as the inputs, that is concentration (gm(-3)), unit flow (h(-1)) and pressure drop (cm of H(2)O). The model developed for the CSTB used two inputs (concentration and unit flow), while the model for the MB had three inputs (concentration, G/L (gas/liquid) ratio, and pressure drop). Sensitivity analysis in the form of absolute average sensitivity (AAS) was performed for all the developed ANN models to ascertain the importance of the different input parameters, and to assess their direct effect on the bioreactors performance. The performance of the models was estimated by the regression

Efficiency of energy recovery from municipal solid waste and the resultant effect on the greenhouse gas balance.

Science.gov (United States)

Gohlke, Oliver

2009-11-01

Global warming is a focus of political interest and life-cycle assessment of waste management systems reveals that energy recovery from municipal solid waste is a key issue. This paper demonstrates how the greenhouse gas effects of waste treatment processes can be described in a simplified manner by considering energy efficiency indicators. For evaluation to be consistent, it is necessary to use reasonable system boundaries and to take the generation of electricity and the use of heat into account. The new European R1 efficiency criterion will lead to the development and implementation of optimized processes/systems with increased energy efficiency which, in turn, will exert an influence on the greenhouse gas effects of waste management in Europe. Promising technologies are: the increase of steam parameters, reduction of in-plant energy consumption, and the combined use of heat and power. Plants in Brescia and Amsterdam are current examples of good performance with highly efficient electricity generation. Other examples of particularly high heat recovery rates are the energy-from-waste (EfW) plants in Malmö and Gothenburg. To achieve the full potential of greenhouse gas reduction in waste management, it is necessary to avoid landfilling combustible wastes, for example, by means of landfill taxes and by putting incentives in place for increasing the efficiency of EfW systems.

Distribution of radium in oil and gas industry wastes from Malaysia

International Nuclear Information System (INIS)

Omar, M.; Ali, H.M.; Abu, M.P.; Kontol, K.M.; Ahmad, Z.; Ahmad, S.H.S.S.; Sulaiman, I.; Hamzah, R.

2004-01-01

Radium concentrations in 470 samples of the various types of waste from oil and gas industries were analysed using gamma spectrometers. The results showed that the radium concentration varied within a wide range. The highest mean 226 Ra and 228 Ra concentrations of 114,300 and 130,120 Bq/kg, respectively, were measured in scales. Overall, 75% of the waste, mostly sludge and extraction residue lies within the normal range of radium concentration in soils of Malaysia. However, some platform sludge can have radium concentration up to 560 Bq/kg

Distribution of radium in oil and gas industry wastes from Malaysia.

Science.gov (United States)

Omar, M; Ali, H M; Abu, M P; Kontol, K M; Ahmad, Z; Ahmad, S H S S; Sulaiman, I; Hamzah, R

2004-05-01

Radium concentrations in 470 samples of the various types of waste from oil and gas industries were analysed using gamma spectrometers. The results showed that the radium concentration varied within a wide range. The highest mean 226Ra and 228Ra concentrations of 114,300 and 130,120 Bq/kg, respectively, were measured in scales. Overall, 75% of the waste, mostly sludge and extraction residue lies within the normal range of radium concentration in soils of Malaysia. However, some platform sludge can have radium concentration up to 560 Bq/kg.

Process and device for the decontamination of the waste gas of the fuel cycle of a fusion reactor of waste gas components containing tritium and/or deuterium in chemically bound form

International Nuclear Information System (INIS)

Penzhorn, R.D.; Glugla, M.; Schuster, P.

1987-01-01

The waste gas of the fuel cycle of a fusion reactor consists of a mixture of about 85% He and Ar and about 15% of deuteriated and/or tritiated ammonia, methane, water and hydrogen, apart from impurities such as CO, CO 2 , N 2 and O 2 . According to the invention, after oxidation of CO to CO 2 on an oxidation catalyst and after the reduction of water to hydrogen and the removal of O 2 by an O 2 getter metal, ammonia and methane are catalytically decomposed. The released hydrogen isotopes are separated for reuse via a membrane permeable to hydrogen, while the decontaminated waste gas is taken away to the environment. (orig.) [de

The effect of dilution on the gas retention behavior of Tank 241-SY- 103 waste

International Nuclear Information System (INIS)

Bredt, P.R.; Tingey, S.M.

1996-01-01

Twenty-five of the 177 underground waste storage tanks on the Hanford Site have been placed on the Flammable Gas watch list. These 25 tanks, containing high-level waste generated during plutonium and uranium processing, have been identified as potentially capable of accumulating flammable gases above the lower flammability limit (Babad et al. 1991). In the case of Tanks 241-SY-101 and 241-SY-103, it has been proposed that diluting the tank waste may mitigate this hazard (Hudson et al. 1995; Stewart et al. 1994). The effect of dilution on the ability of waste from Tank 241-SY-103 to accumulate gas was studied at Pacific Northwest National Laboratory. A similar study has been completed for waste from Tank 241-SY-101 (Bredt et al. 1995). Because of the additional waste-storage volume available in Tank 241-SY-103 and because the waste is assumed to be similar to that currently in Tank 241-SY-101, Tank 241-SY-103 became the target for a demonstration of passive mitigation through in-tank dilution. In 1994, plans for the in-tank dilution demonstration were deferred pending a decision on whether to pursue dilution as a mitigation strategy. However, because Tank 241-SY-103 is an early retrieval target, determination of how waste properties vary with dilution will still be required

Hydrogen-rich gas as a product of two-stage co-gasification of lignite/waste mixtures

Czech Academy of Sciences Publication Activity Database

Straka, Pavel; Bičáková, Olga

2014-01-01

Roč. 39, č. 21 (2014), s. 10987-10995 ISSN 0360-3199 Institutional support: RVO:67985891 Keywords : co-gasification * waste plastics * lignite * hydrogen-rich gas Subject RIV: DM - Solid Waste and Recycling Impact factor: 3.313, year: 2014 http://authors.elsevier.com/sd/article/S0360319914014025

Combination gas-producing and waste-water disposal well. [DOE patent application

Science.gov (United States)

Malinchak, R.M.

1981-09-03

The present invention is directed to a waste-water disposal system for use in a gas recovery well penetrating a subterranean water-containing and methane gas-bearing coal formation. A cased bore hole penetrates the coal formation and extends downwardly therefrom into a further earth formation which has sufficient permeability to absorb the waste water entering the borehole from the coal formation. Pump means are disposed in the casing below the coal formation for pumping the water through a main conduit towards the water-absorbing earth formation. A barrier or water plug is disposed about the main conduit to prevent water flow through the casing except for through the main conduit. Bypass conduits disposed above the barrier communicate with the main conduit to provide an unpumped flow of water to the water-absorbing earth formation. One-way valves are in the main conduit and in the bypass conduits to provide flow of water therethrough only in the direction towards the water-absorbing earth formation.

Regulatory off-gas analysis from the evaporation of Hanford simulated waste spiked with organic compounds.

Science.gov (United States)

Saito, Hiroshi H; Calloway, T Bond; Ferrara, Daro M; Choi, Alexander S; White, Thomas L; Gibson, Luther V; Burdette, Mark A

2004-10-01

After strontium/transuranics removal by precipitation followed by cesium/technetium removal by ion exchange, the remaining low-activity waste in the Hanford River Protection Project Waste Treatment Plant is to be concentrated by evaporation before being mixed with glass formers and vitrified. To provide a technical basis to permit the waste treatment facility, a relatively organic-rich Hanford Tank 241-AN-107 waste simulant was spiked with 14 target volatile, semi-volatile, and pesticide compounds and evaporated under vacuum in a bench-scale natural circulation evaporator fitted with an industrial stack off-gas sampler at the Savannah River National Laboratory. An evaporator material balance for the target organics was calculated by combining liquid stream mass and analytical data with off-gas emissions estimates obtained using U.S. Environmental Protection Agency (EPA) SW-846 Methods. Volatile and light semi-volatile organic compounds (1 mm Hg vapor pressure) in the waste simulant were found to largely exit through the condenser vent, while heavier semi-volatiles and pesticides generally remain in the evaporator concentrate. An OLI Environmental Simulation Program (licensed by OLI Systems, Inc.) evaporator model successfully predicted operating conditions and the experimental distribution of the fed target organics exiting in the concentrate, condensate, and off-gas streams, with the exception of a few semi-volatile and pesticide compounds. Comparison with Henry's Law predictions suggests the OLI Environmental Simulation Program model is constrained by available literature data.

Radiolytic gas production during long-term storage of nuclear wastes

International Nuclear Information System (INIS)

Bibler, N.E.

1976-01-01

Gases produced by in situ radiolysis of sealed solidified nuclear wastes during long-term storage could conceivably breach containment. Therefore, candidate waste forms (matrices containing simulated nuclear wastes) were irradiated with 60 Co-γ and 244 Cm-α radiation. These forms were: cement containing simulated fission product sludges, vermiculite containing organic liquids, and cellulosics contaminated with α-emitting transuranic isotopes. For cement waste forms exposed to γ-radiolysis, an equilibrium hydrogen pressure was reached that was dose rate dependent. For α-radiolysis, equilibrium was not reached. With organic wastes (n-octane on vermiculite), H 2 and traces of CO 2 and CH 4 were produced, and O 2 was consumed with both radiations. Only energy absorbed by the organic material was effective in producing H 2 . At low dose rates with both α- and γ-irradiations, G(H 2 ) was 4.5 and G(-O 2 ) was 5.0. Also, equilibrium was not obtained. For cellulosic material, H 2 , CO 2 , and CO were produced in the ratio of 1.0:0.7:0.3, and O 2 was consumed. With α-radiolysis, G(gas) was dose dependent; measured values ranged from 2.2 to 0.6 as the dose increased. Implications of all these results on long-term storage of radioactive waste are discussed. Some data from an actual nuclear wasteform are also presented

Hazardous waste disposal in relationship to radon gas emanation in atmosphere

International Nuclear Information System (INIS)

Fang, H.Y.

1990-01-01

Radioactive/toxic radon gas (Rn) produced naturally in the ground by the normal decay of uranium (U) and radium (Ra) is widely distributed in trace amounts in the earth's crust. It is a colorless, odorless and tasteless element and is one of the six generally known noble gases which are inert gases lacking the usual or anticipated chemical or biological action. Most radon gas is concentrated in the oxidation belt which is at a relatively shallow depth from the ground surface. Under normal conditions, the amount of radon gas seeping into the atmosphere or entering into residential buildings is very little and will not be harmful to human health. In recent years, due to population growth, a progressive living standard and industrial progress, many natural farm lands, forests and wetlands have been destroyed by conversion into residential and industrial compounds; consequently, such construction activities and industrial waste disposal changes the dynamic equilibrium of the ecosystem which can trigger and accelerate radon gas emanation and mobilization. This change is the major reason for the problem of indoor radon concentration which has significantly increased in recent years. Recent findings indicate that radon is not a totally inert element as previously thought. It can be influenced by local environments such as temperature, pH value, ion exchange, redox reaction, etc. to some degree. Also radon gas interacts with soil, water, air and others; unfortunately, the interface mechanisms between radon and the environment are not yet clearly understood and little information on these aspects is available. In this paper only the hazardous waste disposal causes for radon emanation are discussed. To deal with such complex phenomena, a new approach is presented that assumes radon gas interaction with the environment through dust in the air and suspensions in the water and soil-water system

Analysis of Induced Gas Releases During Retrieval of Hanford Double-Shell Tank Waste

International Nuclear Information System (INIS)

Wells, Beric E.; Cuta, Judith M.; Hartley, Stacey A.; Mahoney, Lenna A.; Meyer, Perry A.; Stewart, Charles W.

2002-01-01

Radioactive waste is scheduled to be retrieved from Hanford double-shell tanks AN-103, AN-104, AN-105, and AW-101 to the vitrification plant beginning about 2009. Retrieval may involve decanting the supernatant liquid and/or mixing the waste with jet pumps. In these four tanks, which contain relatively large volumes of retained gas, both of these operations are expected to induce buoyant displacement gas releases that can potentially raise the tank headspace hydrogen concentration to very near the lower flammability limit. This report describes the theory and detailed physical models for both the supernatant decant and jet mixing processes and presents the results from applying the models to these operations in the four tanks. The technical bases for input parameter distributions are elucidated

Testing various types of agricultural wastes for the production of generator gas

Energy Technology Data Exchange (ETDEWEB)

Kjellstroem, B

1982-05-08

The aim of the project was to get an improved basis for the assessment of aretes which was required for use in a Swedish gas generator. It was found that waste which possessed high contents of ashes with a low melting point were unsuitable as a fuel. Four types of waste were tested. The shells of coconuts were applicable as fuel. The design of the generator had to be modified in order to use pellets of straw or compressed sugar-canes.

Removal of Contaminants from Waste Streams at Gas Evolving Flow-Through Porous Electrodes

International Nuclear Information System (INIS)

Mahmoud Saleh, M.

1999-01-01

Electrochemical techniques have been used for the removal of inorganic and organic toxic materials from industrial waste streams. One of the most important branch of these electrochemical techniques is the flow-through porous electrode. Such systems allow for the continuous operation and hence continuous removal of the contaminants from waste streams at high rates and high efficiency. However, when there is an evolution of gas bubbles with the removal process, the treatment process needs a much different treatment of both the design and the mathematical treatment of the such these systems. The evolving gas bubbles within the electrode decrease the pore electrolyte conductivity of the porous electrodes, decrease the efficiency and make the current more non-uniform. This cause the under utilization of the reaction area and finally make the electrode inoperable. In this work the harmful effects of the gas bubbles on the performance of the porous electrode will be modeled. The model accounts for the effects of kinetic, mass transfer and gas bubbles resistance on the overall performance of the electrode. This will help in optimizing the operating conditions and the cell design

Development of a gas-generation model for the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Brush, L.H.; Storz, L.J.; Garner, J.W.

1993-01-01

Design-basis transuranic (TRU) waste to be emplaced in the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico may generate significant quantities of gas, which may affect the performance of the WIPP with respect to regulations for radioactive and/or chemically hazardous waste constituents. We are developing a model to predict gas generation in WIPP disposal rooms during and after filling and sealing. Currently, the model includes: (1) oxic and anoxic corrosion of steels and other Fe-base alloys, including passivation and depassivation; (2) microbial degradation of cellulosics with O 2 , NO 3 - , FeO(OH), SO 4 2- , or CO 2 as the electron acceptor; (3) α radiolysis of brine; (4) consumption of CO 2 and, perhaps, H 2 S by Ca(OH) 2 (in cementitious materials) and CaO (a potential backfill additive). The code simulates these processes and interactions among them by converting reactants (steels, cellulosics, etc.) to gases and other products at experimentally observed or estimated rates and plotting temporal reaction paths in three-dimensional phase diagrams for solids in the Fe-H 2 O-CO 2 -H 2 -H 2 S system

A new understanding of inert gas narcosis

International Nuclear Information System (INIS)

Zhang Meng; Gao Yi; Fang Haiping

2016-01-01

Anesthetics are extremely important in modern surgery to greatly reduce the patient’s pain. The understanding of anesthesia at molecular level is the preliminary step for the application of anesthetics in clinic safely and effectively. Inert gases, with low chemical activity, have been found to cause anesthesia for centuries, but the mechanism is unclear yet. In this review, we first summarize the progress of theories about general anesthesia, especially for inert gas narcosis, and then propose a new hypothesis that the aggregated rather than the dispersed inert gas molecules are the key to trigger the narcosis to explain the steep dose-response relationship of anesthesia. (topical review)

Coupled multiphase flow and closure analysis of repository response to waste-generated gas at the Waste Isolation Pilot Plant (WIPP)

Energy Technology Data Exchange (ETDEWEB)

Freeze, G.A.; Larson, K.W. [INTERA Inc., Austin, TX (United States); Davies, P.B. [Sandia National Laboratories, Albuquerque, NM (United States)

1995-10-01

A long-term assessment of the Waste Isolation Pilot Plant (WIPP) repository performance must consider the impact of gas generation resulting from the corrosion and microbial degradation of the emplaced waste. A multiphase fluid flow code, TOUGH2/EOS8, was adapted to model the processes of gas generation, disposal room creep closure, and multiphase (brine and gas) fluid flow, as well as the coupling between the three processes. System response to gas generation was simulated with a single, isolated disposal room surrounded by homogeneous halite containing two anhydrite interbeds, one above and one below the room. The interbeds were assumed to have flow connections to the room through high-permeability, excavation-induced fractures. System behavior was evaluated by tracking four performance measures: (1) peak room pressure; (2) maximum brine volume in the room; (3) total mass of gas expelled from the room; and (4) the maximum gas migration distance in an interbed. Baseline simulations used current best estimates of system parameters, selected through an evaluation of available data, to predict system response to gas generation under best-estimate conditions. Sensitivity simulations quantified the effects of parameter uncertainty by evaluating the change in the performance measures in response to parameter variations. In the sensitivity simulations, a single parameter value was varied to its minimum and maximum values, representative of the extreme expected values, with all other parameters held at best-estimate values. Sensitivity simulations identified the following parameters as important to gas expulsion and migration away from a disposal room: interbed porosity; interbed permeability; gas-generation potential; halite permeability; and interbed threshold pressure. Simulations also showed that the inclusion of interbed fracturing and a disturbed rock zone had a significant impact on system performance.

Coupled multiphase flow and closure analysis of repository response to waste-generated gas at the Waste Isolation Pilot Plant (WIPP)

International Nuclear Information System (INIS)

Freeze, G.A.; Larson, K.W.; Davies, P.B.

1995-10-01

A long-term assessment of the Waste Isolation Pilot Plant (WIPP) repository performance must consider the impact of gas generation resulting from the corrosion and microbial degradation of the emplaced waste. A multiphase fluid flow code, TOUGH2/EOS8, was adapted to model the processes of gas generation, disposal room creep closure, and multiphase (brine and gas) fluid flow, as well as the coupling between the three processes. System response to gas generation was simulated with a single, isolated disposal room surrounded by homogeneous halite containing two anhydrite interbeds, one above and one below the room. The interbeds were assumed to have flow connections to the room through high-permeability, excavation-induced fractures. System behavior was evaluated by tracking four performance measures: (1) peak room pressure; (2) maximum brine volume in the room; (3) total mass of gas expelled from the room; and (4) the maximum gas migration distance in an interbed. Baseline simulations used current best estimates of system parameters, selected through an evaluation of available data, to predict system response to gas generation under best-estimate conditions. Sensitivity simulations quantified the effects of parameter uncertainty by evaluating the change in the performance measures in response to parameter variations. In the sensitivity simulations, a single parameter value was varied to its minimum and maximum values, representative of the extreme expected values, with all other parameters held at best-estimate values. Sensitivity simulations identified the following parameters as important to gas expulsion and migration away from a disposal room: interbed porosity; interbed permeability; gas-generation potential; halite permeability; and interbed threshold pressure. Simulations also showed that the inclusion of interbed fracturing and a disturbed rock zone had a significant impact on system performance

Bio-Gas production from municipal sludge waste using anaerobic membrane bioreactor

International Nuclear Information System (INIS)

Lee, Y. H.; Lee, S.

2009-01-01

A laboratory scale anaerobic membrane bioreactor (AnMBR) system for the bio-methane gas production was operated for 60 days with municipal sludge wastes as a sole carbon source. The AnMRR system utilized the external cross-flow membrane module and was equipped with on-line data acquisition which enables continuous monitoring of the performance of both bioreactor and membrane through the analyses of pH, temperature, gas production; permeate flow rate, and transmembrane pressure (TMP). Such a configuration also provides an efficient tool to study rapid variations of monitoring membrane pressure (TMP). (Author)

Treatment of waste water from flue gas cleaning; Behandlung von Abwasser der Rauchgasreinigung

Energy Technology Data Exchange (ETDEWEB)

Ogiermann, Klaus; Meyerhoff, Thomas [Berkefeld - VWS Deutschland GmbH, Celle (Germany); Hagen, Klaus [Berkefeld - VWS Deutschland GmbH, Bayreuth (Germany); Basabe, Juan Luis [HPD Process Engineering S.A., Bilbao (Spain); Vendrup, Michael [Krueger A/S, Soeborg (Denmark)

2012-11-01

Strict limits must be adhered to for treating waste water incurred during flue gas desulphurisation (FGD). One and two-stage precipitation processes have proven themselves in FGD waste water treatment. Metals can be removed with the MetClean {sup registered} process. Another option is evaporation. Waste water ZLD systems (Zero Liquid Discharge) recover, via a falling film evaporator with subsequent crystallisation, more than 98 % of the water and produce, aside from the condensate, only solid material that can be disposed of in landfill. A further development, named ZLD CoLD trademark, significantly reduces the investment and operating costs of this solution. (orig.)

Demonstration of an on-site PAFC cogeneration system with waste heat utilization by a new gas absorption chiller

Energy Technology Data Exchange (ETDEWEB)

Urata, Tatsuo [Tokyo Gas Company, LTD, Tokyo (Japan)

1996-12-31

Analysis and cost reduction of fuel cells is being promoted to achieve commercial on-site phosphoric acid fuel cells (on-site FC). However, for such cells to be effectively utilized, a cogeneration system designed to use the heat generated must be developed at low cost. Room heating and hot-water supply are the most simple and efficient uses of the waste heat of fuel cells. However, due to the short room-heating period of about 4 months in most areas in Japan, the sites having demand for waste heat of fuel cells throughout the year will be limited to hotels and hospitals Tokyo Gas has therefore been developing an on-site FC and the technology to utilize tile waste heat of fuel cells for room cooling by means of an absorption refrigerator. The paper describes the results of fuel cell cogeneration tests conducted on a double effect gas absorption chiller heater with auxiliary waste heat recovery (WGAR) that Tokyo Gas developed in its Energy Technology Research Laboratory.

Controlled Landfill Project in Yolo County, California for Environmental Benefits of Waste Stabilization and Minimization of Greenhouse Gas Emissions

Science.gov (United States)

Yazdani, R.; Augenstein, D.; Kieffer, J.; Cohen, K.

2003-12-01

The Department of Public Works of Yolo County, California, USA has been testing an advanced approach to landfill bioreactors, controlled (or "enhanced") landfilling, at its Yolo County Central Landfill site near Davis, CA, since 1994. Overall objectives have been the management of waste landfilling for: (1) rapid completion of total gas generation; (2) maximum, high-efficiency gas capture; (3) waste volume reduction; and (4) maximum greenhouse gas and carbon sequestration benefits. Methane generation is controlled and enhanced through carefully managed moisture additions, and by taking advantage of landfill temperature elevation. The generated landfill methane, an important greenhouse gas, is recovered with high efficiency through extraction from a porous recovery layer beneath a surface geomembrane cover. Instrumentation included a total of 56 moisture and 15 temperature sensors in the two cells, gas flow monitoring by positive displacement gas meters, and accurate quantification of liquid inputs and outputs. Gas composition, waste volume reduction, base hydrostatic head, and a range of environmental compliance parameters has been monitored since 1995. Partitioning gas tracer tests using the injection of two gases at dilute concentrations in the landfill have also been initiated to compute the fraction of pore space occupied by water between the points of tracer injection and tracer measurement. There has been rapid waste volume reduction in the enhanced cell that corresponds to the solids' reduction to gas. Monitoring is planned for the next several years, until stabilization parameters are determined complete. Encouraging performance is indicated by: (1) sensor data; (2) gas generation results; (3) data from landfill cores; and (4) decomposition-related indicators including rapid volume reduction. When data are synthesized, project results have attractive implications for new approaches to landfill management. Over seven-years, methane recoveries have averaged

Offsite commercial disposal of oil and gas exploration and production waste :availability, options, and cost.

Energy Technology Data Exchange (ETDEWEB)

Puder, M. G.; Veil, J. A.

2006-09-05

A survey conducted in 1995 by the American Petroleum Institute (API) found that the U.S. exploration and production (E&P) segment of the oil and gas industry generated more than 149 million bbl of drilling wastes, almost 18 billion bbl of produced water, and 21 million bbl of associated wastes. The results of that survey, published in 2000, suggested that 3% of drilling wastes, less than 0.5% of produced water, and 15% of associated wastes are sent to offsite commercial facilities for disposal. Argonne National Laboratory (Argonne) collected information on commercial E&P waste disposal companies in different states in 1997. While the information is nearly a decade old, the report has proved useful. In 2005, Argonne began collecting current information to update and expand the data. This report describes the new 2005-2006 database and focuses on the availability of offsite commercial disposal companies, the prevailing disposal methods, and estimated disposal costs. The data were collected in two phases. In the first phase, state oil and gas regulatory officials in 31 states were contacted to determine whether their agency maintained a list of permitted commercial disposal companies dedicated to oil. In the second stage, individual commercial disposal companies were interviewed to determine disposal methods and costs. The availability of offsite commercial disposal companies and facilities falls into three categories. The states with high oil and gas production typically have a dedicated network of offsite commercial disposal companies and facilities in place. In other states, such an infrastructure does not exist and very often, commercial disposal companies focus on produced water services. About half of the states do not have any industry-specific offsite commercial disposal infrastructure. In those states, operators take their wastes to local municipal landfills if permitted or haul the wastes to other states. This report provides state-by-state summaries of the

21 CFR 868.5560 - Gas mask head strap.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a patient's...

Municipal Solid Waste Gasification Plant Integrated With SOFC and Gas Turbine

DEFF Research Database (Denmark)

Bellomare, Filippo; Rokni, Masoud

2012-01-01

An interesting source of producing energy with low pollutants emission and reduced environmental impact are the biomasses; particularly using Municipal Solid Waste (MSW) as fuel, can be a competitive solution not only to produce energy with negligible costs but also to decrease the storage...... in landfills. A Municipal Solid Waste Gasification Plant Integrated with Solid Oxide Fuel Cell (SOFC) and Gas Turbine (GT) has been studied and the plant is called IGSG (Integrated Gasification SOFC and GT). Gasification plant is fed by MSW to produce syngas by which the anode side of a SOFC is fed wherein...

Gas cooled reactor decommissioning. Packaging of waste for disposal in the United Kingdom deep repository

International Nuclear Information System (INIS)

Barlow, S.V.; Wisbey, S.J.; Wood, P.

1998-01-01

United Kingdom Nirex Limited has been established to develop and operate a deep underground repository for the disposal of the UK's intermediate and certain low level radioactive waste. The UK has a significant Gas Cooled Reactor (GCR) programme, including both Magnox and AGR (Advanced Gas-cooled Reactor) capacity, amounting to 26 Magnox reactors, 15 AGR reactors as well as research and prototype reactor units such as the Windscale AGR and the Windscale Piles. Some of these units are already undergoing decommissioning and Nirex has estimated that some 15,000 m 3 (conditioned volume) will come forward for disposal from GCR decommissioning before 2060. This volume does not include final stage (Stage 3) decommissioning arisings from commercial reactors since the generating utilities in the UK are proposing to adopt a deferred safe store strategy for these units. Intermediate level wastes arising from GCR decommissioning needs to be packaged in a form suitable for on-site interim storage and eventual deep disposal in the planned repository. In the absence of Conditions for Acceptance for a repository in the UK, the dimensions, key features and minimum performance requirements for waste packages are defined in Waste Package Specifications. These form the basis for all assessments of the suitability of wastes for disposal, including GCR wastes. This paper will describe the nature and characteristics of GCR decommissioning wastes which are intended for disposal in a UK repository. The Nirex Waste Package Specifications and the key technical issues, which have been identified when considering GCR decommissioning waste against the performance requirements within the specifications, are discussed. (author)

Control of waste well casing vent gas from a thermal enhanced oil recovery operation

International Nuclear Information System (INIS)

Peavy, M.A.; Braun, J.E.

1991-01-01

This paper presents an overview of a waste gas treatment system designed to control emissions from thermally enhanced oil recovery wells. This case study discusses the need, design, installation and operations of the system. Oryx Energy Company (Oryx) operates approximately 940 wells in the Midway-Sunset (MWSS) field under casing vapor recovery systems. The emissions collected from well casing vent gas cotaining hydrocarbons and hydrogen sulfide that are collected and processed through casing vapor recovery skids. These skids are composed of condensers, compressors, and pumps that separate fluids from the waste gas stream. The non-condensible gas is then disposed of in incinerators that reduce the hydrocarbon and sulfur emissions into the atmosphere. Approximately 91,000 lbs/day of hydrocarbon and 10,116 lbs/day of sulfur dioxide are removed from the atmosphere from wells contained within these systems operated by Oryx. These hydrocarbons yield approximately 550 barrels of oil per day (BOPD). The system helps manage the pressure differential from the reservoir into each wellbore and contributes to improved ambient air quality in Kern County, California

Life cycle assessment of fuels for district heating: A comparison of waste incineration, biomass- and natural gas combustion

International Nuclear Information System (INIS)

Eriksson, Ola; Finnveden, Goeran; Ekvall, Tomas; Bjoerklund, Anna

2007-01-01

The aim of this consequential life cycle assessment (LCA) is to compare district heating based on waste incineration with combustion of biomass or natural gas. The study comprises two options for energy recovery (combined heat and power (CHP) or heat only), two alternatives for external, marginal electricity generation (fossil lean or intense), and two alternatives for the alternative waste management (landfill disposal or material recovery). A secondary objective was to test a combination of dynamic energy system modelling and LCA by combining the concept of complex marginal electricity production in a static, environmental systems analysis. Furthermore, we wanted to increase the methodological knowledge about how waste can be environmentally compared to other fuels in district-heat production. The results indicate that combustion of biofuel in a CHP is environmentally favourable and robust with respect to the avoided type of electricity and waste management. Waste incineration is often (but not always) the preferable choice when incineration substitutes landfill disposal of waste. It is however, never the best choice (and often the worst) when incineration substitutes recycling. A natural gas fired CHP is an alternative of interest if marginal electricity has a high fossil content. However, if the marginal electricity is mainly based on non-fossil sources, natural gas is in general worse than biofuels

LOCAL ANESTHETICS IN PATIENTS WITH CARDIOVASCULAR DISEASES.

Directory of Open Access Journals (Sweden)

risto Daskalov

2015-03-01

Full Text Available A significant problem in the dental medicine is pain alleviation. Many studies in the dental anesthesiology result in the production of new agents for locoregional anesthesia. Objective: This article aim to present the results of the last studies on the effect of the local anesthetics used in the oral surgery on patients with cardiovascular diseases. Material: A general review of the existing literature on the effect of the adrenaline, included as vasoconstrictor in the local anesthetics, used in patients with cardiovascular diseases is made. The benefits of vasoconstrictors for the quality of the anesthetic effect are proven. Conclusion: A small amount of adrenaline in the anesthetic solution does not result in complications development in patients with controlled cardiovascular diseases. Articaine is recommended agent of first choice for local anesthesia in the oral surgery.

Mining utilization of residues of exhaust gas cleaning from waste incinerators; Bergtechnische Verwertung von Abgasreinigungsrueckstaenden aus Verbrennungsanlagen

Energy Technology Data Exchange (ETDEWEB)

Werthmann, Rainer [K+S Entsorgung GmbH, Kassel (Germany). Abfallchemie und Zulassungen

2013-03-01

The exhaust gas purification of a household incinerator or a substitute fuel power plant intends to remove dust, heavy metal compounds and acid harmful gases from the exhaust gas in order to comply with the immission-control legal limits. The particulate matter contains volatile heavy metal chlorides which precipitate as a solid matter. The enhanced amount of water-soluble salts is conspicuous. The concentration of soluble components is limited to 10,000 mg/L in the 1:10 eluate due to the landfill regulation. Thus, the residues of exhaust gas cleaning are predestined for an underground waste disposal in salt mines. Under this aspect, the author of the contribution under consideration reports on the mining utilization of residues of exhaust gas cleaning from waste incinerators.

Can anesthetic treatment worsen outcome in status epilepticus?

Science.gov (United States)

Sutter, Raoul; Kaplan, Peter W

2015-08-01

Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus". Copyright © 2015 Elsevier Inc. All rights reserved.

Modelling of far-field gas migration from a deep radioactive waste repository

International Nuclear Information System (INIS)

Rodwell, W.R.; Nash, P.J.

1992-01-01

In assessing the post-closure safety of a deep radioactive waste repository, it is necessary to show that gas generated within the repository can migrate away, through the far-field geology, without affecting repository safety. This paper discusses the contribution of various mechanisms to gas migration through the far field; for example, diffusion of dissolved gas versus gas-phase movement, and bubble flow versus formation of a connected gas stream. It outlines different approaches to modelling gas movement from a repository, with simple semi-analytical models furnishing physical insights into the factors controlling gas migration in the absence of directly applicable experimental data, and more comprehensive numerical computations allowing the exploration of more detailed behaviour when appropriate data is obtained. If gas can induce groundwater movement, this could accelerate the transport of water-borne contaminants. Processes by which this could occur are noted, and the current status of work on possible effects of gas migration on groundwater movement in fractured hard rocks is indicated. 14 refs., 4 figs

Gas generation by corrosion of Cu- and Ti-base materials in simulated waste isolation pilot plant environments

International Nuclear Information System (INIS)

Westerman, R.E.; Telander, M.R.

1994-09-01

A mined geologic repository for demonstrating the safe management and disposal of defense- related transuranic (TRU) waste is being developed by the U.S. Department of Energy near Carlsbad, New Mexico. The site, designated the Waste Isolation Pilot Plant (WIPP), is located in the bedded salt of the Salado Formation, at a depth of 655 m (2150 ft) below the land surface. Eight storage panels of seven rooms each will be mined. The panels, access ways, and shafts will be sealed before the site is decommissioned. At the present time, a large quantity of transuranic wastes are being, temporarily, stored in steel drums and steel waste boxes at waste generator sites. Under current plans, these wastes would be transported to and emplaced within the WIPP site, without additional modification of the original packaging. Additional metal articles (Fe- and Al-based alloys, for example) are contained within the waste containers as contaminated waste materials. Butcher describes several potentially negative effects of highly pressurized gas on the WIPP site. It will tend to retard room closure; it could contribute to fractures within the disturbed rock zone; it has the potential of leaking from the site, possibly causing perceptual, technical, or regulatory concerns; it can contribute to two-phase gas-driven flow from the repository; and it could possibly degrade the repository sealing system. The site-preessurization concerns led to selecting of alternative container materials. Of the metallic container materials considered, copper-base and titanium-base alloys were judged to offer the best combination of properties when fabricability, availability, technology status, cost, and gas-generation potential were taken into account

The comparison of fossil carbon fraction and greenhouse gas emissions through an analysis of exhaust gases from urban solid waste incineration facilities.

Science.gov (United States)

Kim, Seungjin; Kang, Seongmin; Lee, Jeongwoo; Lee, Seehyung; Kim, Ki-Hyun; Jeon, Eui-Chan

2016-10-01

In this study, in order to understand accurate calculation of greenhouse gas emissions of urban solid waste incineration facilities, which are major waste incineration facilities, and problems likely to occur at this time, emissions were calculated by classifying calculation methods into 3 types. For the comparison of calculation methods, the waste characteristics ratio, dry substance content by waste characteristics, carbon content in dry substance, and (12)C content were analyzed; and in particular, CO2 concentration in incineration gases and (12)C content were analyzed together. In this study, 3 types of calculation methods were made through the assay value, and by using each calculation method, emissions of urban solid waste incineration facilities were calculated then compared. As a result of comparison, with Calculation Method A, which used the default value as presented in the IPCC guidelines, greenhouse gas emissions were calculated for the urban solid waste incineration facilities A and B at 244.43 ton CO2/day and 322.09 ton CO2/day, respectively. Hence, it showed a lot of difference from Calculation Methods B and C, which used the assay value of this study. It is determined that this was because the default value as presented in IPCC, as the world average value, could not reflect the characteristics of urban solid waste incineration facilities. Calculation Method B indicated 163.31 ton CO2/day and 230.34 ton CO2/day respectively for the urban solid waste incineration facilities A and B; also, Calculation Method C indicated 151.79 ton CO2/day and 218.99 ton CO2/day, respectively. This study intends to compare greenhouse gas emissions calculated using (12)C content default value provided by the IPCC (Intergovernmental Panel on Climate Change) with greenhouse gas emissions calculated using (12)C content and waste assay value that can reflect the characteristics of the target urban solid waste incineration facilities. Also, the concentration and (12)C content

Waste isolation pilot plant performance assessment: Radionuclide release sensitivity to diminished brine and gas flows to/from transuranic waste disposal areas

Energy Technology Data Exchange (ETDEWEB)

Day, Brad A.; Camphouse, R. C.; Zeitler, Todd R. [Sandia National Laboratories, Carlsbad (United States)

2017-03-15

Waste Isolation Pilot Plant repository releases are evaluated through the application of modified parameters to simulate accelerated creep closure, include capillary pressure effects on relative permeability, and increase brine and gas saturation in the operations and experimental (OPS/EXP) areas. The modifications to the repository model result in increased pressures and decreased brine saturations in waste areas and increased pressures and brine saturations in the OPS/EXP areas. Brine flows up the borehole during a hypothetical drilling intrusion are nearly identical and brine flows up the shaft are decreased. The modified parameters essentially halt the flow of gas from the southern waste areas to the northern nonwaste areas, except as transported through the marker beds and anhydrite layers. The combination of slightly increased waste region pressures and very slightly decreased brine saturations result in a modest increase in spallings and no significant effect on direct brine releases, with total releases from the Culebra and cutting and caving releases unaffected. Overall, the effects on total high-probability mean releases from the repository are insignificant, with total low-probability mean releases minimally increased. It is concluded that the modified OPS/EXP area parameters have an insignificant effect on the prediction of total releases.

Development of bio-gas using crop wastes and pig dung ...

African Journals Online (AJOL)

Effect of crop wastes on the production of pig dung bio-gas was investigated. Beans husks, peels of cassava, plantain and yam were processed with fresh dung of pig. Bacterial and fungal counts in the digesting materials ranged from 1.5 x 1011cfu/ml to 3.5 x 1011cfu/ml and 0.8 x 1011sfu/ml to 1.4 x1011sfu/ml respectively.

Design of off-gas cleaning systems for high-level waste vitrification

International Nuclear Information System (INIS)

Hanson, M.S.; Kaser, J.D.

1976-01-01

High-level wastes are generally nitric acid solutions. Vitrification converts the nitrate salts to oxides, forming nitrogen oxides (NO/sub x/) as a by-product. These NO/sub x/ releases can be controlled by nitric acid recovery or by conversion of the NO/sub x/ to an acceptable species for release, such as N 2 O or N 2 . The off-gas system must also be capable of controlling any fission products which may be voltatilized in appreciable quantities and may be controlled in the off-gas system by absorption or adsorption. Whichever method is used, the recovered fission products must somehow be converted to a safe disposal form. Proposed off-gas systems are described, and areas requiring research and development are discussed

Characterization and Regeneration of Pt-Catalysts Deactivated in Municipal Waste Flue Gas

DEFF Research Database (Denmark)

Rasmussen, Søren Birk; Kustov, Arkadii; Due-Hansen, Johannes

2006-01-01

Severe deactivation was observed for industrially aged catalysts used in waste incineration plants and tested in lab-scale. Possible compounds that cause deactivation of these Pt-based CO oxidation catalysts have been studied. Kinetic observations of industrial and model catalysts showed...... that siloxanes were the most severe catalyst poisons, although acidic sulfur compounds also caused deactivation. Furthermore, a method for on-site regeneration without shutdown of the catalytic flue gas cleaning system has been developed, i.e. an addition of H-2/N-2 gas to the off-gas can completely restore...... the activity of the deactivated catalysts. (c) 2006 Elsevier B.V. All rights reserved....

The use of compound topical anesthetics: a review.

Science.gov (United States)

Kravitz, Neal D

2007-10-01

The author reviewed the history of, federal regulations regarding, risks of and adverse drug reactions of five compound topical anesthetics: tetracaine, adrenaline/epinephrine and cocaine (TAC); lidocaine, adrenaline/epinephrine and tetracaine (LET); lidocaine, tetracaine and phenylephrine (TAC 20 percent Alternate); lidocaine, prilocaine and tetracaine (Profound); and lidocaine, prilocaine, tetracaine and phenylephrine with thickeners (Profound PET). The author reviewed clinical trials, case reports, descriptive articles, and U.S. Food and Drug Administration (FDA) regulations and recent public advisory warnings regarding the federal approval of and risks associated with the use of compound topical anesthetics. Compound topical anesthetics are neither FDA-regulated nor -unregulated. Some compounding pharmacies bypass the new FDA drug approval process, which is based on reliable scientific data and ensures that a marketed drug is safe, effective, properly manufactured and accurately labeled. Two deaths have been attributed to the lay use of compound topical anesthetics. In response, the FDA has announced the strengthening of its efforts against unapproved drug products. Compound topical anesthetics may be an effective alternative to local infiltration for some minimally invasive dental procedures; however, legitimate concerns exist in regard to their safety. Until they become federally regulated, compound topical anesthetics remain unapproved drug products whose benefits may not outweigh their risks for dental patients.

Studies Related to Chemical Mechanisms of Gas Formation in Hanford High-Level Nuclear Wastes

International Nuclear Information System (INIS)

Barefield, E. Kent; Liotta, Charles L.; Neumann, Henry M.

2002-01-01

The objective of this work is to develop a more detailed mechanistic understanding of the thermal reactions that lead to gas production in certain high-level waste storage tanks at the Hanford, Washington site. Prediction of the combustion hazard for these wastes and engineering parameters for waste processing depend upon both a knowledge of the composition of stored wastes and the changes that they undergo as a result of thermal and radiolytic decomposition. Since 1980 when Delagard first demonstrated that gas production (H2and N2O initially, later N2 and NH3)in the affected tanks was related to oxidative degradation of metal complexants present in the waste, periodic attempts have been made to develop detailed mechanisms by which the gases were formed. These studies have resulted in the postulation of a series of reactions that account for many of the observed products, but which involve several reactions for which there is limited, or no, precedent. For example, Al(OH)4 has been postulated to function as a Lewis acid to catalyze the reaction of nitrite ion with the metal complexants, NO is proposed as an intermediate, and the ratios of gaseous products may be a result of the partitioning of NO between two or more reactions. These reactions and intermediates have been the focus of this project since its inception in 1996

Radiolytic gas formation in high-level liquid waste solutions

International Nuclear Information System (INIS)

Brodda, B.-G.; Dix, Siegfried; Merz, E.R.

1989-01-01

High-level fission product waste solutions originating from the first-cycle raffinate stream of spent fast breeder reactor fuel reprocessing have been investigated gas chromatographically for their radiolytic and chemical gas production. The solutions showed considerable formation of hydrogen, carbon dioxide and dinitrogen oxide, whereas atmospheric oxygen was consumed completely within a short time. In particular, carbon dioxide resulted from the radiolytic degradation of entrained organic solvent. After nearly complete degradation of the organic solvent, the influence of hydrazine and nitrogen dioxide on hydrogen formation was investigated. Hydrazinium hydroxide led to the formation of dinitrogen oxide and nitrogen. After 60 d, the concentration of dinitrogen oxide had reduced to zero, whereas the amount of nitrogen formed had reached a maximum. This may be explained by simultaneous chemical and radiolytic reactions leading to the formation of dinitrogen oxide and nitrogen and photolytic fission of dinitrogen oxide. Addition of sodium nitrite resulted in the rapid formation of dinitrogen oxide. The rate of hydrogen production was not changed significantly after the addition of hydrazine or nitrite. The results indicate that under normal operating conditions no dangerous hydrogen radiolysis yields should develop in the course of reprocessing and high-level liquid waste tank storage. Organic entrainment may lead to enhanced radiolytic decomposition and thus to considerable hydrogen production rates and pressure build-up in closed systems. (author)

Vasoconstriction Potency Induced by Aminoamide Local Anesthetics Correlates with Lipid Solubility

Directory of Open Access Journals (Sweden)

Hui-Jin Sung

2012-01-01

Full Text Available Aminoamide local anesthetics induce vasoconstriction in vivo and in vitro. The goals of this in vitro study were to investigate the potency of local anesthetic-induced vasoconstriction and to identify the physicochemical property (octanol/buffer partition coefficient, pKa, molecular weight, or potency of local anesthetics that determines their potency in inducing isolated rat aortic ring contraction. Cumulative concentration-response curves to local anesthetics (levobupivacaine, ropivacaine, lidocaine, and mepivacaine were obtained from isolated rat aorta. Regression analyses were performed to determine the relationship between the reported physicochemical properties of local anesthetics and the local anesthetic concentration that produced 50% (ED50 of the local anesthetic-induced maximum vasoconstriction. We determined the order of potency (ED50 of vasoconstriction among local anesthetics to be levobupivacaine > ropivacaine > lidocaine > mepivacaine. The relative importance of the independent variables that affect the vasoconstriction potency is octanol/buffer partition coefficient > potency > pKa > molecular weight. The ED50 in endothelium-denuded aorta negatively correlated with the octanol/buffer partition coefficient of local anesthetics (r2=0.9563; P<0.001. The potency of the vasoconstriction in the endothelium-denuded aorta induced by local anesthetics is determined primarily by lipid solubility and, in part, by other physicochemical properties including potency and pKa.

Nocebo-induced hyperalgesia during local anesthetic injection.

Science.gov (United States)

Varelmann, Dirk; Pancaro, Carlo; Cappiello, Eric C; Camann, William R

2010-03-01

Common practice during local anesthetic injection is to warn the patient using words such as: "You will feel a big bee sting; this is the worst part." Our hypothesis was that using gentler words for administration of the local anesthetic improves pain perception and patient comfort. One hundred forty healthy women at term gestation requesting neuraxial analgesia were randomized to either a "placebo" ("We are going to give you a local anesthetic that will numb the area and you will be comfortable during the procedure") or "nocebo" ("You are going to feel a big bee sting; this is the worst part of the procedure") group. Pain was assessed immediately after the local anesthetic skin injection using verbal analog scale scores of 0 to 10. Median verbal analog scale pain scores were lower when reassuring words were used compared with the harsher nocebo words (3 [2-4] vs 5 [3-6]; P words improves the subjective experience during invasive procedures.

Guides to pollution prevention: Selected hospital waste streams

International Nuclear Information System (INIS)

1990-06-01

The hazardous wastes generated by general medical and surgical hospitals are small in volume relative to those of industrial facilities; however, the wastes are of a wide variety. Some of the hazardous materials used by hospitals that become part of their waste streams include chemotherapy and antineoplastic chemicals, solvents, formaldehyde, photographic chemicals, radionuclides, mercury, waste anesthetic gases; and other toxic, corrosive and miscellaneous chemicals. Additional wastes such as infectious waste, incinerator exhaust, laundry-related waste, utility wastes, and trash were not addressed in the guide. Reducing the generation of these materials at the source, or recycling the wastes on- or off-site, will benefit hospitals by reducing disposal costs and lowering the liabilities associated with hazardous waste disposal. The guide provides an overview of hospital waste generating processes and presents options for minimizing waste generation through source reduction and recycling

Anesthetic salts used in dentistry: a literature review

Directory of Open Access Journals (Sweden)

Guilherme Klein Parise

2017-08-01

Full Text Available Local anesthetics allow a better and suitable control of pain in patients that submit to dental treatments. The pharmacology of local anesthetics is too complex, therefore it is important to know how to select the correct drug to each procedure to be accomplished. Thus, it is concluded that the production of a literary review material is of great relevance in order to gather current and important information about the local anesthetics most used in dentistry.

Questioning the accuracy of greenhouse gas accounting from agricultural waste: a case study.

Science.gov (United States)

Chung, Matthew L; Shilton, Andrew N; Guieysse, Benoit; Pratt, Chris

2013-01-01

The New Zealand Greenhouse Gas Inventory (the NZ Inventory) uses country-specific data to quantify CH emissions from anaerobic ponds treating dairy farm effluent (315 Gg CO equivalent [CO-e] in 2009). In this study, we used literature data to: (i) evaluate the accuracy of the NZ Inventory's parameters used to quantify these CH emissions; and (ii) determine whether the NZ Inventory's scope is capturing the full spectrum of sources with bio-CH potential entering anaerobic ponds. The research indicated that the current NZ Inventory methodology is underestimating CH emissions from anaerobic ponds across New Zealand by 264 to 603 Gg CO-e annually. Moreover, the NZ Inventory is currently not accounting for (i) manure from supplementary feed pads and stand-off pads (annual CH emissions = 207-330 Gg CO-e); (ii) waste milk (153-280 Gg CO-e); and (iii) supplementary feed waste (90-216 Gg CO-e). Annual CH emissions from anaerobic ponds on dairy farms across New Zealand are thus more likely to be 1029 to 1744 Gg CO-e, indicating that the NZ Inventory is reporting as little as 18% of actual CH emissions produced by this sector. These additional wastes are not accounted for in the methodology prescribed by the Intergovernmental Panel on Climate Change for estimating CH emissions from dairy manure. Consequently, other significant dairying nations will also probably be underestimating their waste CH emissions. Our research highlights that, if governments attempt to include country-specific emission factors in their greenhouse gas inventories, these factors must be based on an assessment of the full spectrum of sources contributing to greenhouse gas emissions within any given sector. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Potential for a solids fire during an ITP waste tank deflagration and the impact on gas pressure

International Nuclear Information System (INIS)

Thomas, J.K.

1993-07-01

During the In-Tank Precipitation (ITP) process, solid deposits may form at the water-line on internal waste tank surfaces. These solids may be combustible due to the presence of tetraphenylborate compounds and hence there is a potential that a waste tank deflagration could ignite a solids fire. The work described in this report evaluates the potential for a waste tank deflagration to ignite a solids fire and the subsequent effect on gas pressure. Thermal analyses were performed using a one-dimensional conduction model, radiative heat flux values calculated with the Deflagration Pressure Analysis Code (DPAC), and effective deposit properties calculated from the component properties. It was shown that a solids fire could only be ignited by a waste tank deflagration for a limited range of cases. For the best-estimate mixtures, a solids fire could not be ignited prior to the time the peak gas pressure is reached and would not increase the peak pressure. For the upper-bound mixtures, the thickness of the solid layer which could be ignited is insufficient to increase the energy released by the deflagration by a significant amount. It was also shown that these conclusions are relatively insensitive to uncertainties related to deposit composition. Thus, the contribution from a solids fire to the gas pressure resulting from a waste tank deflagration may be neglected

Comparison of alternative flue gas dry treatment technologies in waste-to-energy processes.

Science.gov (United States)

Dal Pozzo, Alessandro; Antonioni, Giacomo; Guglielmi, Daniele; Stramigioli, Carlo; Cozzani, Valerio

2016-05-01

Acid gases such as HCl and SO2 are harmful both for human health and ecosystem integrity, hence their removal is a key step of the flue gas treatment of Waste-to-Energy (WtE) plants. Methods based on the injection of dry sorbents are among the Best Available Techniques for acid gas removal. In particular, systems based on double reaction and filtration stages represent nowadays an effective technology for emission control. The aim of the present study is the simulation of a reference two-stage (2S) dry treatment system performance and its comparison to three benchmarking alternatives based on single stage sodium bicarbonate injection. A modelling procedure was applied in order to identify the optimal operating configuration of the 2S system for different reference waste compositions, and to determine the total annual cost of operation. Taking into account both operating and capital costs, the 2S system appears the most cost-effective solution for medium to high chlorine content wastes. A Monte Carlo sensitivity analysis was carried out to assess the robustness of the results. Copyright © 2016. Published by Elsevier Ltd.

Comparison of anesthetic agents in the sea otter

Energy Technology Data Exchange (ETDEWEB)

Williams, T.D.; Kocher, F.H.

1978-01-01

Five anesthetic agents (CI744, etorphine, fentanyl, ketamine hydrochloride, and halothane) were tested to establish the dosage of a safe, effective, short-acting anesthetic for use in the sea otter. Etorphine, at a dosage of 0.75 mg per adult otter and used in conjunction with diazepam, at a dosage of 1.25 mg per adult otter, met most of the requirements for use under field conditions. Halothane, administered through an anesthetic machine, proved to be effective for use in a veterinary hospital.

The benefits of flue gas recirculation in waste incineration.

Science.gov (United States)

Liuzzo, Giuseppe; Verdone, Nicola; Bravi, Marco

2007-01-01

Flue gas recirculation in the incinerator combustion chamber is an operative technique that offers substantial benefits in managing waste incineration. The advantages that can be obtained are both economic and environmental and are determined by the low flow rate of fumes actually emitted if compared to the flue gas released when recirculation is not conducted. Simulations of two incineration processes, with and without flue gas recirculation, have been carried out by using a commercial flowsheeting simulator. The results of the simulations demonstrate that, from an economic point of view, the proposed technique permits a greater level of energy recovery (up to +3%) and, at the same time, lower investment costs as far as the equipment and machinery constituting the air pollution control section of the plant are concerned. At equal treatment system efficiencies, the environmental benefits stem from the decrease in the emission of atmospheric pollutants. Throughout the paper reference is made to the EC legislation in the field of environmental protection, thus ensuring the general validity in the EU of the foundations laid and conclusions drawn henceforth. A numerical example concerning mercury emission quantifies the reported considerations and illustrates that flue gas recirculation reduces emission of this pollutant by 50%.

Cogeneration from poultry industry wastes: Indirectly fired gas turbine application

International Nuclear Information System (INIS)

Bianchi, M.; Cherubini, F.; De Pascale, A.; Peretto, A.; Elmegaard, B.

2006-01-01

The availability of wet biomass as waste from a lot of industrial processes, from agriculture and farms and the need to meet the environmental standards force to investigate all options in order to dispose this waste. The possible treatments usually strongly depend on biomass characteristics, namely water content, density, organic content, heating value, etc. In particular, some of these wastes can be burnt in special plants, using them as energy supply for different processes. The study carried out with this paper is concerned with the promising utilization of the organic wastes from an existing poultry industry as fuel. Different plant configurations have been considered in order to make use of the oil and of the meat and bone meal, which are the by-products of the chicken cooking process. In particular, the process plant can be integrated with an energy supply plant, which can consist of an indirectly fired gas turbine. Moreover, a steam turbine plant or a simplified system for the supply of the only technological steam are investigated and compared. Thermodynamic and economic analysis have been carried out for the examined configurations in order to outline the basic differences in terms of energy savings/production and of return of the investments

Development of a simple and sensitive method for the characterization of odorous waste gas emissions by means of solid-phase microextraction (SPME) and GC-MS/olfactometry.

Science.gov (United States)

Kleeberg, K K; Liu, Y; Jans, M; Schlegelmilch, M; Streese, J; Stegmann, R

2005-01-01

A solid-phase microextraction (SPME) method has been developed for the extraction of odorous compounds from waste gas. The enriched compounds were characterized by gas chromatography-mass spectrometry (GC-MS) and gas chromatography followed by simultaneous flame ionization detection and olfactometry (GC-FID/O). Five different SPME fiber coatings were tested, and the carboxen/polydimethylsiloxane (CAR/PDMS) fiber showed the highest ability to extract odorous compounds from the waste gas. Furthermore, parameters such as exposure time, desorption temperature, and desorption time have been optimized. The SPME method was successfully used to characterize an odorous waste gas from a fat refinery prior to and after waste gas treatment in order to describe the treatment efficiency of the used laboratory scale plant which consisted of a bioscrubber/biofilter combination and an activated carbon adsorber. The developed method is a valuable approach to provide detailed information of waste gas composition and complements existing methods for the determination of odors. However, caution should be exercised if CAR/PDMS fibers are used for the quantification of odorous compounds in multi-component matrices like waste gas emissions since the relative affinity of each analyte was shown to differ according to the total amount of analytes present in the sample.

Determination of Intrinsic Permeability for Packed Waste of Indonesian Solid Waste

Directory of Open Access Journals (Sweden)

Benno Rahardyan

2010-11-01

Full Text Available Gas permeability and intrinsic permeability are the major parameters to promote aeration for packed waste. The objectives of this research are to identify physical parameters of gas transfer from a various type of packed wastes and examine ventilation design theory for landfill to enhance waste stabilization. Method to determine value of gas permeability and intrinsic permeability for packed waste is by flushing the packed column containing various type and physical characteristics of wastes with an air pump. Permeability was calculated by measuring pressure gradient on sampling points of the column using inclined manometer at distance 10 cm, 23 cm, 46 cm, 69 cm, 92 cm and 115 cm from origin. Gas permeability is specifically relied on physical parameters of wastes as follows, density, moisture content, particle size and gas velocity on the surface of compacted waste layer. Compost has finer pore structure and smaller pore size than leaves as well as mixed organic (65% and inorganic wastes (35%. The experiment found the intrinsic permeability of leaves waste are in the order of 10-11 to 10-8 m2, 10-11 to 10-9 m2 for compost and 10-9 m2 for mixed organic (65% and inorganic wastes (35%.

Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements

DEFF Research Database (Denmark)

Cai, Zuansi; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

2003-01-01

Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filter in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration...... more than 5 MPa after 7 days. The tank leaching tests revealed that leaching of heavy metals was not significantly affected by the use of chemically stabilised flue gas ashes from waste incineration. Assuming that diffusion controls the leaching process it was calculated that less than 1% of the metals...... would teach during a 100-year period from a 0.5 m thick concrete stab exposed to water on one side. Leaching of the common ions Ca, Cl, Na and SO4 was increased 3-20 times from the specimens with chemically stabilised flue gas ashes from waste incineration. However, the quantities leached were still...

Retrofit acid gas emission control for municipal waste incineration application of dry sorbent injection

International Nuclear Information System (INIS)

Zmuda, J.T.; Smith, P.V.

1991-01-01

Dry sorbent injection (DSI) has been successfully demonstrated on coal fired boiler applications as a means of reducing sulfur dioxide emissions. More recently, the dry sorbent injection process was applied to an existing municipal waste incinerator to provide acid gas emission controls. The results obtained from the successful demonstration of the sorbent injection system on an existing municipal incinerator are presented. Removal efficiencies of compounds such as HCl, SO 2 , SO 3 , mercury, and others by the use of sorbent injection are shown. Effects of the DSI system on downstream equipment, such as electrostatic precipitators, fabric filters, ash handling systems, and waste management is included. The impacts of the DSI system on the furnace is also discussed. In this paper a discussion of dry sorbent injection as a means of reducing acid gas and other emissions from existing municipal waste incinerators which may be affected by the regulations is presented. An application case study will outline typical exhaust conditions, expected pollution reductions, capital and operating costs, and type of available sorbents and their costs

Challenges Encountered Using Ophthalmic Anesthetics in Space Medicine

Science.gov (United States)

Bayuse, T.; Law, J.; Alexander, D.; Moynihan, S.; LeBlanc, C.; Langford, K.; Magalhaes, L.

2015-01-01

On orbit, ophthalmic anesthetics are used for tonometry and off-nominal corneal examinations. Proparacaine has been flown traditionally. However, the manufacturers recently changed its storage requirements from room temperature storage to refrigerated storage to preserve stability and prolong the shelf-life. Since refrigeration on orbit is not readily available and there were stability concerns about flying proparacaine unrefrigerated, tetracaine was selected as an alternative ophthalmic anesthetic in 2013. We will discuss the challenges encountered flying and using these anesthetics on the International Space Station.

Local Anesthetics: Review of Pharmacological Considerations

Science.gov (United States)

Becker, Daniel E; Reed, Kenneth L

2012-01-01

Local anesthetics have an impressive history of efficacy and safety in medical and dental practice. Their use is so routine, and adverse effects are so infrequent, that providers may understandably overlook many of their pharmacotherapeutic principles. The purpose of this continuing education article is to provide a review and update of essential pharmacology for the various local anesthetic formulations in current use. Technical considerations will be addressed in a subsequent article. PMID:22822998

A SIGNAL ENHANCED PORTABLE RAMAN PROBE FOR ANESTHETIC GAS MONITORING

Directory of Open Access Journals (Sweden)

S. Schlüter

2015-03-01

Full Text Available The spontaneous Raman scattering technique is an excellent tool for a quantitative analysis of multi-species gas mixtures. It is a noninvasive optical method for species identification and gas phase concentration measurement of all Raman active molecules, since the intensity of the species specific Raman signal is linearly dependent on the concentration. Applying a continuous wave (CW laser it typically takes a few seconds to capture a gas phase Raman spectrum at room temperature. Nevertheless in contrast to these advantages the weak Raman signal intensity is a major drawback. Thus, it is still challenging to detect gas phase Raman spectra in alow-pressure regime with a temporal resolution of only a few 100 ms. In this work a fully functional gas phase Raman system for measurements in the low-pressure regime (p ≥ 980 hPa (absolute is presented. It overcomes the drawback of a weak Raman signal by using a multipass cavity. A description of the sensor setup and of the multipass arrangement will be presented. Moreover the complete functionality of the sensor system will be demonstrated by measurements at an anesthesia simulator under clinical relevant conditions and in comparison to a conventional gas monitor.

A proposal for a test method for assessment of hazard property HP 12 ("Release of an acute toxic gas") in hazardous waste classification - Experience from 49 waste.

Science.gov (United States)

Hennebert, Pierre; Samaali, Ismahen; Molina, Pauline

2016-12-01

A stepwise method for assessment of the HP 12 is proposed and tested with 49 waste samples. The hazard property HP 12 is defined as "Release of an acute toxic gas": waste which releases acute toxic gases (Acute Tox. 1, 2 or 3) in contact with water or an acid. When a waste contains a substance assigned to one of the following supplemental hazards EUH029, EUH031 and EUH032, it shall be classified as hazardous by HP 12 according to test methods or guidelines (EC, 2014a, 2014b). When the substances with the cited hazard statement codes react with water or an acid, they can release HCl, Cl 2 , HF, HCN, PH 3 , H 2 S, SO 2 (and two other gases very unlikely to be emitted, hydrazoic acid HN 3 and selenium oxide SeO 2 - a solid with low vapor pressure). Hence, a method is proposed:For a set of 49 waste, water addition did not produce gas. Nearly all the solid waste produced a gas in contact with hydrochloric acid in 5 min in an automated calcimeter with a volume >0.1L of gas per kg of waste. Since a plateau of pressure is reached only for half of the samples in 5 min, 6 h trial with calorimetric bombs or glass flasks were done and confirmed the results. Identification of the gases by portable probes showed that most of the tested samples emit mainly CO 2 . Toxic gases are emitted by four waste: metallic dust from the aluminum industry (CO), two air pollution control residue of industrial waste incinerator (H 2 S) and a halogenated solvent (organic volatile(s) compound(s)). HF has not been measured in these trials started before the present definition of HP 12. According to the definition of HP 12, only the H 2 S emission of substances with hazard statement EUH031 is accounted for. In view of the calcium content of the two air pollution control residue, the presence of calcium sulphide (EUH031) can be assumed. These two waste are therefore classified potentially hazardous for HP 12, from a total of 49 waste. They are also classified as hazardous for other properties (HP 7

Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

Energy Technology Data Exchange (ETDEWEB)

Khongkrapan, Parin; Thanompongchart, Patipat; Tippayawong, Nakorn; Kiatsiriroat, Tanongkiat [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand)

2013-07-01

In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2) in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

Waste incinerating plant

Energy Technology Data Exchange (ETDEWEB)

1972-12-01

This plant is provided with a NKK-Ferunst type reciprocating stage fire lattice which has a good ventilating effect and a proper stirring and loosening effect, achieving a high combustion rate, and has also a gas flow system by which gas can flow in the reverse direction to adjust its flow for seasonal variations in the quality of waste. Also, a room in which the exhaust gas is mixed is provided in this plant as a help for the complete neutralization and combustion of acid gas such as hydrogen chloride and imperfect combustion gas from plastic waste contained in wastes. In this system, waste can accept a sufficient radiant heat from the combustion gas, the furnace wall, and the ceiling; even on the post combustion fire lattice the ashes are given heat enough to complete the post combustion, so that it can be completely reduced to ashes. For these reasons, this type of incinerator is suitable for the combustion of low-calorie wastes such as city wastes. The harmful gases resulting from the combustion of wastes are treated completely by desulfurization equipment which can remove the oxides of sulfur. This type of plant also can dispose of a wide variety of wastes, and is available in several capacities from 30 tons per 8 hr to 1,200 tons per 24 hr.

Addition of lacal anesthetics to contrast media. Pt. 2

International Nuclear Information System (INIS)

Nilsson, P.; Almen, T.; Golman, K.; Jonsson, K.; Nyman, U.; Malmoe Allmaenna Sjukhus

1988-01-01

The acute intravenous toxicity (i.v. LD 50 ) of solutions of the ratio 1.5 contrast media metrizoate or diatrizoate and the ratio 3.0 contrast medium metrizamide was determined in mice with and without the addition of local anesthetics to the solutions. The two local anesthetics mepivacaine or lidocaine were added to final concentrations up to 2.0 mg/ml of the contrast medium solutions. This corresponds to clinically used concentrations. All additions of local anesthetics to the solutions increased the mortalities caused by the contrast medium solutions. Addition of local anesthetics to a final concentration of 2 mg/ml approximately doubled the acute intravenous toxicity of the contrast media. The ratio 3 contrast media produce less hypertonic solutions than the ratio 1.5 contrast media and should be preferred for angiography because they cause less pain and do not require the addition of local anesthetics which increase the acute toxicity of the solutions. (orig.)

Gas Fermentation-A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks.

Science.gov (United States)

Liew, FungMin; Martin, Michael E; Tappel, Ryan C; Heijstra, Björn D; Mihalcea, Christophe; Köpke, Michael

2016-01-01

There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields.

Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses

Science.gov (United States)

Peterson, B. V.; Hummerick, M.; Roberts, M. S.; Krumins, V.; Kish, A. L.; Garland, J. L.; Maxwell, S.; Mills, A.

2004-01-01

Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis,1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste

Developments in odour control and waste gas treatment biotechnology: a review.

Science.gov (United States)

Burgess, J E; Parsons, S A; Stuetz, R M

2001-02-01

Waste and wastewater treatment processes produce odours, which can cause a nuisance to adjacent populations and contribute significantly to atmospheric pollution. Sulphurous compounds are responsible for acid rain and mist; many organic compounds of industrial origin contribute to airborne public health concerns, as well as environmental problems. Waste gases from industry have traditionally been treated using physicochemical processes, such as scrubbing, adsorption, condensation, and oxidation, however, biological treatment of waste gases has gained support as an effective and economical option in the past few decades. One emergent technique for biological waste gas treatment is the use of existing activated sludge plants as bioscrubbers, thus treating the foul air generated by other process units of the wastewater treatment system on site, with no requirement for additional units or for interruption of wastewater treatment. Limited data are available regarding the performance of activated sludge diffusion of odorous air in spite of numerous positive reports from full-scale applications in North America. This review argues that the information available is insufficient for precise process design and optimization, and simultaneous activated sludge treatment of wastewater and airborne odours could be adopted worldwide.

Implementation of Exhaust Gas Recirculation for Double Stage Waste Heat Recovery System on Large Container Vessel

DEFF Research Database (Denmark)

Andreasen, Morten; Marissal, Matthieu; Sørensen, Kim

2014-01-01

Concerned to push ships to have a lower impact on the environment, the International Maritime Organization are implementing stricter regulation of NOx and SOx emissions, called Tier III, within emission control areas (ECAs). Waste Heat Recovery Systems (WHRS) on container ships consist...... of recovering some of the waste heat from the exhaust gas. This heat is converted into electrical energy used on-board instead of using auxiliary engines. Exhaust Gas Recirculation (EGR) systems, are recirculating a part of the exhaust gas through the engine combustion chamber to reduce emissions. WHRS combined...... with EGR is a potential way to improve system efficiency while reducing emissions. This paper investigates the feasibility of combining the two systems. EGR dilutes the fuel, lowering the combustion temperature and thereby the formation of NOx, to reach Tier III limitation. A double stage WHRS is set up...

Comparison of the temperature and humidity in the anesthetic breathing circuit among different anesthetic workstations: Updated guidelines for reporting parallel group randomized trials.

Science.gov (United States)

Choi, Yoon Ji; Min, Sam Hong; Park, Jeong Jun; Cho, Jang Eun; Yoon, Seung Zhoo; Yoon, Suk Min

2017-06-01

For patients undergoing general anesthesia, adequate warming and humidification of the inspired gases is very important. The aim of this study was to evaluate the differences in the heat and moisture content of the inspired gases with low-flow anesthesia using 4 different anesthesia machines. The patients were divided into 11 groups according to the anesthesia machine used (Ohmeda, Excel; Avance; Dräger, Cato; and Primus) and the fresh gas flow (FGF) rate (0.5, 1, and 4 L/min). The temperature and absolute humidity of the inspired gas in the inspiratory limbs were measured at 5, 10, 15, 30, 45, 60, 75, 90, 105, and 120 minutes in 9 patients scheduled for total thyroidectomy or cervical spine operation in each group. The anesthesia machines of Excel, Avance, Cato, and Primus did not show statistically significant changes in the inspired gas temperatures over time within each group with various FGFs. They, however, showed statistically significant changes in the absolute humidity of the inspired gas over time within each group with low FGF anesthesia (P humidity of the inspired gas over time within each group with an FGF of 4 L/min (P humidities of the inspired gas for all anesthesia machines were lower than the recommended values. There were statistical differences in the provision of humidity among different anesthesia workstations. The Cato and Primus workstations were superior to Excel and Avance. However, even these were unsatisfactory in humans. Therefore, additional devices that provide inspired gases with adequate heat and humidity are needed for those undergoing general anesthetic procedures.

Technoeconomic Optimization of Waste Heat Driven Forward Osmosis for Flue Gas Desulfurization Wastewater Treatment

Energy Technology Data Exchange (ETDEWEB)

Gingerich, Daniel B [Carnegie Mellon Univ., Pittsburgh, PA (United States); Bartholomew, Timothy V [Carnegie Mellon Univ., Pittsburgh, PA (United States); Mauter, Meagan S [Carnegie Mellon Univ., Pittsburgh, PA (United States)

2017-06-26

With the Environmental Protection Agency’s recent Effluent Limitation Guidelines for Steam Electric Generators, power plants are having to install and operate new wastewater technologies. Many plants are evaluating desalination technologies as possible compliance options. However, the desalination technologies under review that can reduce wastewater volume or treat to a zero-liquid discharges standard have a significant energy penalty to the plant. Waste heat, available from the exhaust gas or cooling water from coal-fired power plants, offers an opportunity to drive wastewater treatment using thermal desalination technologies. One such technology is forward osmosis (FO). Forward osmosis utilizes an osmotic pressure gradient to passively pull water from a saline or wastewater stream across a semi-permeable membrane and into a more concentrated draw solution. This diluted draw solution is then fed into a distillation column, where the addition of low temperature waste heat can drive the separation to produce a reconcentrated draw solution and treated water for internal plant reuse. The use of low-temperature waste heat decouples water treatment from electricity production and eliminates the link between reducing water pollution and increasing air emissions from auxiliary electricity generation. In order to evaluate the feasibility of waste heat driven FO, we first build a model of an FO system for flue gas desulfurization (FGD) wastewater treatment at coal-fired power plants. This model includes the FO membrane module, the distillation column for draw solution recovery, and waste heat recovery from the exhaust gas. We then add a costing model to account for capital and operating costs of the forward osmosis system. We use this techno-economic model to optimize waste heat driven FO for the treatment of FGD wastewater. We apply this model to three case studies: the National Energy Technology Laboratory (NETL) 550 MW model coal fired power plant without carbon

Some study on radiation resistance and reliability of piston ring of waste gas compressor for fast breeder experimental reactor

International Nuclear Information System (INIS)

Muramatsu, Takio; Hidaka, Tsukasa

1976-01-01

In the fast breeder experimental reactor ''Joyo'', the gaseous wastes such as reactor cover argon, reactor seal nitrogen gas, fuel handling waste gas etc. shall be collected, compressed and storaged for decaying their activity. Compressors applied in the above process have new type oilless piston rings of Teflon filled with graphite, which might be affected by radioactivity of the waste gases. This report deals with some study on the gamma iradiation effects on the plastic piston rings such as tensile strength, elongation, shock and hardness effects under several irradiation doses and on durability test of the irradiated piston rings under the same compression ratio. (auth.)

Design and manufacturing concrete cells for shielding and storing radioactive semi liquid waste (resin) from MPR-GAS

International Nuclear Information System (INIS)

Pudjijanto-MS; Bahdir-Johan

2003-01-01

Semi liquid or quasi solid waste on Multipurpose Reactor G.A. Siwabessy (MPR-GAS) produced from operating resin rinsing systems and resin disposal systems during changes insert trap resin. Volume of the disposal resin waste in the filter mixed-bed per operation rinsing period are approx. 1.00 m 3 (in the Primary Cooling Water Treatment System) with activity ∼ 18.6 Ci/m 3 (0.688 TBq/m 3 ), 0.50 m 3 (in the Radioisotope Storage Pool Water Treatment System) with activity approx ∼ 0.162 Ci/m 3 (5.99 x 10 3 MBq/m 3 ) and 0.50 m 3 (in the Interim Spent Fuel Storage Pool Water Treatment System) with activity ∼ 0.162 Ci/m 3 (5.99 x 10 3 MBq/m 3 ) respectively. On the discharging and unloading, the gross radioactivity concentration of the resin waste loaded in the disposal resin waste tank are approx. 10 Ci/m 3 (0.37 TBq/m 3 ). After 6 months delayed, this activity is still 0.32 Ci/m 3 (11.84 GBq/m 3 ). Based on this data, some concrete cells to storage resin waste as semi liquid or quasi solid waste produced continuously by MPR-GAS installation has been designed and manufactured eternally

The recovery of waste and off-gas in Large Combustion Plants subject to IPPC National Permit in Italy.

Science.gov (United States)

Di Marco, Giuseppe; Manuzzi, Raffaella

2018-03-01

The recovery of off-gas, waste, and biomass in Large Combustion Plants for energy production gives the opportunity to recycle waste and by-products and to recover materials produced in agricultural and industrial activities. The paper illustrates the Italian situation regarding the production of energy from off-gas, biomass, and waste in Large Combustion Plants subject to Integrated Pollution Prevention and Control (IPPC) National Permit. Moreover, it focuses on the 4 Italian Large Combustion Plants producing energy from biomass and waste. For these ones it illustrates the specific issues related to and provides a description of the solutions adopted in the 4 Italian plants. Given that air emission performance is the most relevant aspect of this kind of plants, the paper specifically focuses and reports results about this subject. In particular, in Italy among 113 LCPs subject to IPPC National Permit we have found that 4 plants use as fuel waste (i.e. solid or liquid biomasses and Solid Recovered Fuels), or a mixture of waste and traditional fuels (co-combustion of Solid Recovered Fuels and coal), and that 11 plants use as fuel off-gases listed in Annex X (i.e. Refinery Fuel Gas, Syngas, and gases produced in iron and steel industries). Moreover, there are 2 IPPC chemical plants that recovery energy from different off-gases not listed in Annex X. Regarding the 4 LCPs that produce energy from waste combustion or co-combustion, we find that they take into account all the specific issues related to this kind of plants (i.e. detailed waste characterization, waste acceptance procedures, waste handling and storage, waste pretreatment and emissions to air), and adopt solutions that are best available techniques to prevent pollution. Moreover for one of these plants, the only one for which we have a significant set of monitoring data because it obtained the IPPC National Permit in 2008, we find that energy efficiency and air emissions of the principal pollutants are in

Operating Room Environment Control. Part A: a Valve Cannister System for Anesthetic Gas Adsorption. Part B: a State-of-the-art Survey of Laminar Flow Operating Rooms. Part C: Three Laminar Flow Experiments

Science.gov (United States)

Meyer, J. S.; Kosovich, J.

1973-01-01

An anesthetic gas flow pop-off valve canister is described that is airtight and permits the patient to breath freely. Once its release mechanism is activated, the exhaust gases are collected at a hose adapter and passed through activated coal for adsorption. A survey of laminar air flow clean rooms is presented and the installation of laminar cross flow air systems in operating rooms is recommended. Laminar flow ventilation experiments determine drying period evaporation rates for chicken intestines, sponges, and sections of pig stomach.

Detomidine reduces isoflurane anesthetic requirement (MAC) in horses.

Science.gov (United States)

Steffey, Eugene P; Pascoe, Peter J

2002-10-01

To quantitate the dose- and time-related magnitude of the anesthetic sparing effect of, and selected physiological responses to detomidine during isoflurane anesthesia in horses. Randomized cross-over study. Three, healthy, young adult horses weighing 485 ± 14 kg. Horses were anesthetized on two occasions to determine the minimum alveolar concentration (MAC) of isoflurane in O 2 and then to measure the anesthetic sparing effect (time-related MAC reduction) following IV detomidine (0.03 and 0.06 mg kg -1 ). Selected common measures of cardiopulmonary function, blood glucose and urinary output were also recorded. Isoflurane MAC was 1.44 ± 0.07% (mean ± SEM). This was reduced by 42.8 ± 5.4% and 44.8 ± 3.0% at 83 ± 23 and 125 ± 36 minutes, respectively, following 0.03 and 0.06 mg kg -1 , detomidine. The MAC reduction was detomidine dose- and time-dependent. There was a tendency for mild cardiovascular and respiratory depression, especially following the higher detomidine dose. Detomidine increased both blood glucose and urine flow; the magnitude of these changes was time- and dose-dependent CONCLUSIONS: Detomidine reduces anesthetic requirement for isoflurane and increases blood glucose concentration and urine flow in horses. These changes were dose- and time-related. The results imply potent anesthetic sparing actions by detomidine. The detomidine-related increased urine flow should be considered in designing anesthetic protocols for individual horses. Copyright © 2002 Association of Veterinary Anaesthetists and American College of Veterinary Anesthesia and Analgesia. Published by Elsevier Ltd. All rights reserved.

Validation of the bispectral index as an indicator of anesthetic depth in Thoroughbred horses anesthetized with sevoflurane.

Science.gov (United States)

Tokushige, Hirotaka; Kakizaki, Masashi; Ode, Hirotaka; Okano, Atsushi; Okada, Jun; Kuroda, Taisuke; Wakuno, Ai; Ohta, Minoru

2016-01-01

To evaluate the bispectral index (BIS) as an indicator of anesthetic depth in Thoroughbred horses, BIS values were measured at multiple stages of sevoflurane anesthesia in five horses anesthetized with guaifenesin and thiopental following premedication with xylazine. There was no significant difference between the BIS values recorded at end-tidal sevoflurane concentrations of 2.8% (median 60 ranging from 47 to 68) and 3.5% (median 71 ranging from 49 to 82) in anesthetized horses. These BIS values during anesthesia were significantly lower (Phorses (median 98 ranging from 98 to 98) or sedated horses (median 92 ranging from 80 to 93). During the recovery phase, the BIS values gradually increased over time but did not significantly increase until the horses showed movement. In conclusion, the BIS value could be useful as an indicator of awakening during the recovery period in horses, as previous reported.

Co-processing of agricultural plastic waste and switchgrass via tail gas reactive pyrolysis

Science.gov (United States)

Mixtures of agricultural plastic waste in the form of polyethylene hay bale covers (PE) (4-37%) and switchgrass were investigated using the US Department of Agriculture’s tail gas reactive pyrolysis (TGRP) at different temperatures (400-570 deg C). TGRP of switchgrass and plastic mixtures significan...

Intravenous sub-anesthetic ketamine for perioperative analgesia

Directory of Open Access Journals (Sweden)

Andrew W Gorlin

2016-01-01

Full Text Available Ketamine, an N-methyl-d-aspartate antagonist, blunts central pain sensitization at sub-anesthetic doses (0.3 mg/kg or less and has been studied extensively as an adjunct for perioperative analgesia. At sub-anesthetic doses, ketamine has a minimal physiologic impact though it is associated with a low incidence of mild psychomimetic symptoms as well as nystagmus and double vision. Contraindications to its use do exist and due to ketamine′s metabolism, caution should be exercised in patients with renal or hepatic dysfunction. Sub-anesthetic ketamine improves pain scores and reduces perioperative opioid consumption in a broad range of surgical procedures. In addition, there is evidence that ketamine may be useful in patients with opioid tolerance and for preventing chronic postsurgical pain.

Recovery Act: Brea California Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

Energy Technology Data Exchange (ETDEWEB)

Galowitz, Stephen

2012-12-31

The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Olinda Landfill near Brea, California. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting Project reflected a cost effective balance of the following specific sub-objectives: • Meeting the environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas • Utilizing proven and reliable technology and equipment • Maximizing electrical efficiency • Maximizing electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Olinda Landfill • Maximizing equipment uptime • Minimizing water consumption • Minimizing post-combustion emissions • The Project produced and will produce a myriad of beneficial impacts. o The Project created 360 FTE construction and manufacturing jobs and 15 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. o By combining state-of-the-art gas clean up systems with post combustion emissions control systems, the Project established new national standards for best available control technology (BACT). o The Project will annually produce 280,320 MWh’s of clean energy o By destroying the methane in the landfill gas, the Project will generate CO2 equivalent reductions of 164,938 tons annually. The completed facility produces 27.4 MWnet and operates 24 hours a day, seven days a week.

Development and testing of prototype alpha waste incinerator off-gas systems

International Nuclear Information System (INIS)

Freed, E.J.; Becker, G.W.

1982-01-01

A test program is in progress at Savannah River Laboratory (SRL) to confirm and develop incinerator design technology for an SRP production Alpha Waste Incinerator (AWI) to be built in the mid-1980's. The Incinerator Components Test Facility (ICTF) is a full-scale (5 kg/h), electrically heated, controlled-air prototype incinerator built to burn nonradioactive solid waste. The incinerator has been operating successfully at SRL since March 1979 and has met or exceeded all design criteria. During the first 1-1/2 years of operation, liquid scrubbers were used to remove particulates and hydrochloric acid from the incinerator exhaust gases. A dry off-gas system is currently being tested to provide data to Savannah River Plant's proposed AWI

Thirty ways to temporize on waste

International Nuclear Information System (INIS)

Marshall, E.

1987-01-01

Congress must decide in the coming weeks whether it should try to revive the civil nuclear waste program or yield to politics and apply an anesthetic for a couple of years. The program is in such poor shape that Congress may have to do something. Thirty proposals have been introduced; most would derail or postpone the present plan for disposing of nuclear waste. About 50 members of Congress would like to call a moratorium on field research at potential waste repository sites. They see this as the best way out of the present impasse-if a moratorium is a way out. But this decision would come as a blow to the nuclear utilities, already hard-pressed on several fronts. The last thing they want is a general review of the waste program. The options available for dispersing of nuclear wastes are discussed

Microbial aspects of gas generation from low level radioactive waste simulant

International Nuclear Information System (INIS)

Kidby, D.W.; Billington, R.S.

1992-01-01

This report details the experimental work undertaken to further the understanding of the kinetics of methanogenesis associated with radioactive LLW disposal. A series of treatments were established by inoculating a LLW simulant and investigating the kinetics of methanogenesis in small Wheaton bottles. Treatments were set up to study the effects of waste compaction, the addition of metal to the simulant, the initial aerobic phase, pH and temperature on gas production. A separate experiment was also established to determine whether cellulose in the simulant acted as a biogas precursor. Results are presented from the head space gas analysis and the solid and liquid phase analyses undertaken over a 600 day period. (Author)

Gas generation in deep radioactive waste repositories: a review of processes, controls and models

International Nuclear Information System (INIS)

Jones, M.A.

1990-10-01

Gas generation within radioactive waste repositories may produce two general problems: 1) breaching of engineered and natural barriers due to high gas pressures; 2) enhanced radiological risk due to reduced groundwater travel times and/or greater aqueous or gaseous activities reaching the biosphere. As a result of these concerns, HMIP must be aware of the current status of relevant research, together with any associated deficiencies. This report addresses the current status of published research on near-field gas generation from worldwide sources and documents the important gas generating processes, the factors controlling them and models available to simulate them. In the absence of suitable models, outline technical specifications for corrosion and microbial degradation gas generation models are defined and the deficiencies in the current understanding of gas generation are highlighted; a conceptual research programme to correct these deficiencies is presented. (author)

Co-pyrolysis of waste tire/coal mixtures for smokeless fuel, maltenes and hydrogen-rich gas production

Czech Academy of Sciences Publication Activity Database

Bičáková, Olga; Straka, Pavel

2016-01-01

Roč. 116, MAY 15 (2016), s. 203-213 ISSN 0196-8904 Grant - others:OPPK(XE) CZ.2.16/3.1.00/21538 Program:OPPK Institutional support: RVO:67985891 Keywords : waste tires * coal * co-pyrolysis * smokeless fuel * tar * hydrogen -rich gas Subject RIV: DM - Solid Waste and Recycling Impact factor: 5.589, year: 2016 http://www.sciencedirect.com/science/article/pii/S0196890416300991

Roadmapping the Resolution of Gas Generation Issues in Packages Containing Radioactive Waste/Materials - A Status Report

International Nuclear Information System (INIS)

Luke, D.E.; Hamp, S.

2002-01-01

Gas generation issues, particularly hydrogen, have been an area of concern for the transport and storage of radioactive materials and waste in the Department of Energy (DOE) Complex. Potentially combustible gases can be generated through a variety of reactions, including chemical reactions and radiolytic decomposition of hydrogen-containing material. Since transportation regulations prohibit shipment of explosives and radioactive materials together, it was decided that hydrogen generation was a problem that warranted the execution of a high-level roadmapping effort. This paper discusses the major gas generation issues within the DOE Complex and the research that has been and is being conducted by the transuranic (TRU) waste, nuclear materials, and spent nuclear fuels (SNF) programs within DOE's Environmental Management (EM) organizations to address gas generation concerns. This paper presents a ''program level'' roadmap that links technology development to program needs and identifies the probability of success in an effort to understand the programmatic risk associated with the issue of gas generation. This paper also presents the status of the roadmap and follow-up activities

Preparation of activated carbon from waste plastics polyethylene terephthalate as adsorbent in natural gas storage

Science.gov (United States)

Yuliusman; Nasruddin; Sanal, A.; Bernama, A.; Haris, F.; Ramadhan, I. T.

2017-02-01

The main problem is the process of natural gas storage and distribution, because in normal conditions of natural gas in the gas phase causes the storage capacity be small and efficient to use. The technology is commonly used Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG). The weakness of this technology safety level is low because the requirement for high-pressure CNG (250 bar) and LNG requires a low temperature (-161°C). It takes innovation in the storage of natural gas using the technology ANG (Adsorbed Natural Gas) with activated carbon as an adsorbent, causing natural gas can be stored in a low pressure of about 34.5. In this research, preparation of activated carbon using waste plastic polyethylene terephthalate (PET). PET plastic waste is a good raw material for making activated carbon because of its availability and the price is a lot cheaper. Besides plastic PET has the appropriate characteristics as activated carbon raw material required for the storage of natural gas because the material is hard and has a high carbon content of about 62.5% wt. The process of making activated carbon done is carbonized at a temperature of 400 ° C and physical activation using CO2 gas at a temperature of 975 ° C. The parameters varied in the activation process is the flow rate of carbon dioxide and activation time. The results obtained in the carbonization process yield of 21.47%, while the yield on the activation process by 62%. At the optimum process conditions, the CO2 flow rate of 200 ml/min and the activation time of 240 minutes, the value % burn off amounted to 86.69% and a surface area of 1591.72 m2/g.

Anesthetic equipment, facilities and services available for pediatric ...

African Journals Online (AJOL)

Background: Facilities and equipment are known to contribute to improved patient care and outcome. Hospitals for sub‑specialized pediatric anesthetic service are routinely available worldwide. In Nigeria, such hospitals now exist. It is therefore relevant to study the facilities and equipment available for pediatric anesthetic ...

[Anesthetic management of four patients with Fournier syndrome].

Science.gov (United States)

Sato, Rui; Tomioka, Toshiya; Orii, Ryo; Yamada, Yoshitsugu

2008-03-01

We experienced anesthetic managements of four patients with Fournier syndrome. In the anesthetic management of the patients with Fournier syndrome the following three points should be kept in mind; (a) the necessity of careful preoperative examination, (b) the better anesthesia, and (c) the careful postoperative care.

THE EFFECT OF LOCAL ANESTHETICS ON TEAR PRODUCTION

African Journals Online (AJOL)

that local anesthetics measure only basic secretion thus reducing normal tear production/secretion, which is both reflex and basic. This could be attributed to the fact that local anesthetics have an adrenergic potentiating effects and because lacrimal fluid receive a preganglionic parasympathetic supply from lacrimal muscles ...

Computed tomography and blood gas analysis of anesthetized bloodhounds with induced pneumothorax

International Nuclear Information System (INIS)

Walker, M.; Hartsfield, S.; Matthews, N.; White, G.; Slater, M.; Thoos, J.

1993-01-01

Increasingly severe degrees of pneumothorax were produced in 6 adult anesthetized bloodhounds. Computed tomography (CT) of the thorax was performed on each dog to evaluate the effects of pneumo thorax on thoracic and on pulmonary cross-sectional area (TA and PA). Arterial PO 2 (PaO 2 ) and PCO 2 (PaCO 2 ), heart rate (HR), and mean arterial blood pressure (MAP) were determined and related to the severity of pneumothorax. Volumes of air equal to 1, 1.5 and 2 times functional residual capacity of the lung produced approximately 33%, 40%, and 50% reductions in pulmonary area respectively. These amounts of atelectasis correspond to a radiographically “moderate” degree of pneumothorax. As severity of pneumothorax increased, thoracic area consistently increased, PaO 2 consistently decreased, and PaCO 2 consistently increased, with all being statistically significant relationships (p 0.2)

Process for separation of inert fission gases for waste gas of a reprocessing plant for nuclear fuel

International Nuclear Information System (INIS)

Schnez, H.

1980-01-01

The inert fission gases Kr and Xe released in the resolver and other waste gases are taken to an acid regeneration plant. Part of the inert fission gases is separated by compression, cooling and filtering and deposited. The other part flows back to the resolver as flushing gas so that a flushing gas circuit is formed, which prevents explosive gas mixtures occurring. (DG) [de

Blood profiles in unanesthetized and anesthetized guinea pigs (Cavia porcellus).

Science.gov (United States)

Williams, Wendy R; Johnston, Matthew S; Higgins, Sarah; Izzo, Angelo A; Kendall, Lon V

2016-01-01

The guinea pig is a common animal model that is used in biomedical research to study a variety of systems, including hormonal and immunological responses, pulmonary physiology, corticosteroid response and others. However, because guinea pigs are evolutionarily a prey species, they do not readily show behavioral signs of disease, which can make it difficult to detect illness in a laboratory setting. Minimally invasive blood tests, such as complete blood counts and plasma biochemistry assays, are useful in both human and veterinary medicine as an initial diagnostic technique to rule in or rule out systemic illness. In guinea pigs, phlebotomy for such tests often requires that the animals be anesthetized first. The authors evaluated hematological and plasma biochemical effects of two anesthetic agents that are commonly used with guinea pigs in a research setting: isoflurane and a combination of ketamine and xylazine. Hematological and plasma biochemical parameters were significantly different when guinea pigs were under either anesthetic, compared to when they were unanesthetized. Plasma proteins, liver enzymes, white blood cells and red blood cells appeared to be significantly altered by both anesthetics, and hematological and plasma biochemical differences were greater when guinea pigs were anesthetized with the combination of ketamine and xylazine than when they were anesthetized with isoflurane. Overall these results indicate that both anesthetics can significantly influence hematological and plasma biochemical parameters in guinea pigs.

Upgraded biogas from municipal solid waste for natural gas substitution and CO2 reduction--a case study of Austria, Italy, and Spain.

Science.gov (United States)

Starr, Katherine; Villalba, Gara; Gabarrell, Xavier

2015-04-01

Biogas is rich in methane and can be further purified through biogas upgrading technologies, presenting a viable alternative to natural gas. Landfills and anaerobic digestors treating municipal solid waste are a large source of such biogas. They therefore offer an attractive opportunity to tap into this potential source of natural gas while at the same time minimizing the global warming impact resulting from methane emissions in waste management schemes (WMS) and fossil fuel consumption reduction. This study looks at the current municipal solid waste flows of Spain, Italy, and Austria over one year (2009), in order to determine how much biogas is generated. Then it examines how much natural gas could be substituted by using four different biogas upgrading technologies. Based on current waste generation rates, exploratory but realistic WMS were created for each country in order to maximize biogas production and potential for natural gas substitution. It was found that the potential substitution of natural gas by biogas resulting from the current WMS seems rather insignificant: 0.2% for Austria, 0.6% for Italy and 0.3% for Spain. However, if the WMS is redesigned to maximize biogas production, these figures can increase to 0.7% for Austria, 1% for Italy and 2% for Spain. Furthermore, the potential CO2 reduction as a consequence of capturing the biogas and replacing fossil fuel can result in up to a 93% reduction of the annual national waste greenhouse gas emissions of Spain and Italy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inventories and reduction scenarios of urban waste-related greenhouse gas emissions for management potential.

Science.gov (United States)

Yang, Dewei; Xu, Lingxing; Gao, Xueli; Guo, Qinghai; Huang, Ning

2018-06-01

Waste-related greenhouse gas (GHG) emissions have been recognized as one of the prominent contributors to global warming. Current urban waste regulations, however, face increasing challenges from stakeholders' trade-offs and hierarchic management. A combined method, i.e., life cycle inventories and scenario analysis, was employed to investigate waste-related GHG emissions during 1995-2015 and to project future scenarios of waste-driven carbon emissions by 2050 in a pilot low carbon city, Xiamen, China. The process-based carbon analysis of waste generation (prevention and separation), transportation (collection and transfer) and disposal (treatment and recycling) shows that the main contributors of carbon emissions are associated with waste disposal processes, solid waste, the municipal sector and Xiamen Mainland. Significant spatial differences of waste-related CO 2e emissions were observed between Xiamen Island and Xiamen Mainland using the carbon intensity and density indexes. An uptrend of waste-related CO 2e emissions from 2015 to 2050 is identified in the business as usual, waste disposal optimization, waste reduction and the integrated scenario, with mean annual growth rates of 8.86%, 8.42%, 6.90% and 6.61%, respectively. The scenario and sensitivity analysis imply that effective waste-related carbon reduction requires trade-offs among alternative strategies, actions and stakeholders in a feasible plan, and emphasize a priority of waste prevention and collection in Xiamen. Our results could benefit to the future modeling of urban multiple wastes and life-cycle carbon control in similar cities within and beyond China. Copyright © 2018 Elsevier B.V. All rights reserved.

Thermal and combined thermal and radiolytic reactions involving nitrous oxide, hydrogen, and nitrogen in the gas phase; comparison of gas generation rates in supernate and solid fractions of Tank 241-SY-101 simulated waste

International Nuclear Information System (INIS)

Bryan, S.A.; Pederson, L.R.

1995-03-01

This report summarizes progress made in evaluating me by which flammable gases are generated in Hanford double-shell tank wastes, based on the results of laboratory tests using simulated waste mixtures. Work described in this report. was conducted at Pacific Northwest Laboratory (PNL) for the Flammable Gas Safety Project, the purpose of which is to develop information needed to support Westinghouse Hanford Company (WHC) in their efforts to ensure the safe interim storage of wastes at the Hanford Site. This work is related to gas generation studies being performed at Georgia Institute of Technology (GIT), under subcontract to PNL, using simulated wastes, and to studies being performed at VMC using actual wastes

Valorization of Calcium Carbonate-Based Solid Wastes for the Treatment of Hydrogen Sulfide from the Gas Phase

OpenAIRE

Pham Xuan , Huynh; Pham Minh , Doan; Galera Martinez , Marta; Nzihou , Ange; Sharrock , Patrick

2015-01-01

International audience; This paper focuses on the valorization of calcium carbonate-based solid wastes for theremoval of hydrogen sulfide from gas phase. Two solid wastes taken from industrial sites for theproduction of sodium carbonate and sodium bicarbonate by the Solvay process® were analyzedby different physico-chemical methods. Calcium carbonate was found as the main component ofboth the solid wastes. Trace amounts of other elements such as Mg, Al, Fe, Si, Cl, Na etc. werealso present in...

Hydrogen production from food wastes and gas post-treatment by CO2 adsorption

International Nuclear Information System (INIS)

Redondas, V.; Gómez, X.; García, S.; Pevida, C.; Rubiera, F.; Morán, A.; Pis, J.J.

2012-01-01

Highlights: ► The dark fermentation process of food wastes was studied over an extended period. ► Decreasing the HRT of the process negatively affected the specific gas production. ► Adsorption of CO 2 was successfully attained using a biomass type activated carbon. ► H 2 concentration in the range of 85–95% was obtained for the treated gas-stream. - Abstract: The production of H 2 by biological means, although still far from being a commercially viable proposition, offers great promise for the future. Purification of the biogas obtained may lead to the production of highly concentrated H 2 streams appropriate for industrial application. This research work evaluates the dark fermentation of food wastes and assesses the possibility of adsorbing CO 2 from the gas stream by means of a low cost biomass-based adsorbent. The reactor used was a completely stirred tank reactor run at different hydraulic retention times (HRTs) while the concentration of solids of the feeding stream was kept constant. The results obtained demonstrate that the H 2 yields from the fermentation of food wastes were affected by modifications in the hydraulic retention time (HRT) due to incomplete hydrolysis. The decrease in the duration of fermentation had a negative effect on the conversion of the substrate into soluble products. This resulted in a lower amount of soluble substrate being available for metabolisation by H 2 producing microflora leading to a reduction in specific H 2 production. Adsorption of CO 2 from a gas stream generated from the dark fermentation process was successfully carried out. The data obtained demonstrate that the column filled with biomass-derived activated carbon resulted in a high degree of hydrogen purification. Co-adsorption of H 2 S onto the activated carbon also took place, there being no evidence of H 2 S present in the bio-H 2 exiting the column. Nevertheless, the concentration of H 2 S was very low, and this co-adsorption did not affect the CO 2

The effect of dilution on the gas-retention behavior of Tank 241-SY-101 waste

International Nuclear Information System (INIS)

Bredt, P.R.; Tingey, S.M.; Shade, E.H.

1995-09-01

The effect of dilution on gas retention in waste from Tank 241-SY-101 was investigated. A composite sample was prepared from material collected during the Window ''C'' and Window ''E'' sampling events. The composite contained material from both the convective and nonconvective layer in the proportions existing in the tank. Operation of the mixer pump in Tank 241-SY-101 has homogenized the tank material, and dilution of the current waste would require additional mixing; therefore, no attempt was made to use unhomogenized tank waste to prepare the composite. The composite was diluted with 2 M NaOH at ratios of 0.5:1, 0.75: 1, 1:1, and 3:1 per volume (2 M NaOH:tank waste)

Contribution of plastic waste recovery to greenhouse gas (GHG) savings in Spain.

Science.gov (United States)

Sevigné-Itoiz, Eva; Gasol, Carles M; Rieradevall, Joan; Gabarrell, Xavier

2015-12-01

This paper concentrates on the quantification of greenhouse gas (GHG) emissions of post-consumer plastic waste recovery (material or energy) by considering the influence of the plastic waste quality (high or low), the recycled plastic applications (virgin plastic substitution or non-plastic substitution) and the markets of recovered plastic (regional or global). The aim is to quantify the environmental consequences of different alternatives in order to evaluate opportunities and limitations to select the best and most feasible plastic waste recovery option to decrease the GHG emissions. The methodologies of material flow analysis (MFA) for a time period of thirteen years and consequential life cycle assessment (CLCA) have been integrated. The study focuses on Spain as a representative country for Europe. The results show that to improve resource efficiency and avoid more GHG emissions, the options for plastic waste management are dependent on the quality of the recovered plastic. The results also show that there is an increasing trend of exporting plastic waste for recycling, mainly to China, that reduces the GHG benefits from recycling, suggesting that a new focus should be introduced to take into account the split between local recycling and exporting. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aspects on the gas generation and migration in repositories for high level waste in salt formations

International Nuclear Information System (INIS)

Ruebel, Andre; Buhmann, Dieter; Meleshyn, Artur; Moenig, Joerg; Spiessl, Sabine

2013-07-01

In a deep geological repository for high-level waste, gases may be produced during the post-closure phase by several processes. The generated gases can potentially affect safety relevant features and processes of the repository, like the barrier integrity, the transport of liquids and gases in the repository and the release of gaseous radionuclides from the repository into the biosphere. German long-term safety assessments for repositories for high-level waste in salt which were performed prior 2010 did not explicitly consider gas transport and the consequences from release of volatile radionuclides. Selected aspects of the generation and migration of gases in repositories for high-level waste in a salt formation are studied in this report from the viewpoint of the performance assessment. The knowledge on the availability of water in the repository, in particular the migration of salt rock internal fluids in the temperature field of the radioactive waste repository towards the emplacement drifts, was compiled and the amount of water was roughly estimated. Two other processes studied in this report are on the one hand the release of gaseous radionuclides from the repository and their potential impact in the biosphere and on the other hand the transport of gases along the drifts and shafts of the repository and their interaction with the fluid flow. The results presented show that there is some gas production expected to occur in the repository due to corrosion of container material from water disposed of with the backfill and inflowing from the host rock during the thermal phase. If not dedicated gas storage areas are foreseen in the repository concept, these gases might exceed the storage capacity for gases in the repository. Consequently, an outflow of gases from the repository could occur. If there are failed containers for spent fuel, radioactive gases might be released from the containers into the gas space of the backfill and subsequently transported together

Relationship between potency and boiling point of general anesthetics: a thermodynamic consideration.

Science.gov (United States)

Dastmalchi, S; Barzegar-Jalali, M

2000-07-20

The most important group of nonspecific drugs is that of the general anesthetics. These nonspecific compounds vary greatly in structure, from noble gases such as Ar or Xe to complex steroids. Since the development of clinical anesthesia over a century ago, there has been a vast amount of research and speculation concerning the mechanism of action of general anesthetics. Despite these efforts, the exact mechanism remains unknown. Many theories of narcosis do not explain how unconsciousness is produced at a molecular level, but instead relate some physicochemical property of anesthetic agents to their anesthetic potencies. In this paper, we address some of those physicochemical properties, with more emphasis on correlating the anesthetic potency of volatile anesthetics to their boiling points based on thermodynamic principles.

Laboratory Evaporation Testing Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

Energy Technology Data Exchange (ETDEWEB)

Adamson, Duane J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, Charles A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, Charles L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilmarth, William R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-01-01

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream, LAW Off-Gas Condensate, from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of canistered glass waste forms. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to be within acceptable concentration ranges in the LAW glass. Diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the impact of potential future disposition of this stream in the Hanford tank farms, and investigates auxiliary evaporation to enable another disposition path. Unless an auxiliary evaporator is used, returning the stream to the tank farms would require evaporation in the 242-A evaporator. This stream is expected to be unusual because it will be very high in corrosive species that are volatile in the melter

Laboratory Evaporation Testing Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

International Nuclear Information System (INIS)

Adamson, Duane J.; Nash, Charles A.; McCabe, Daniel J.; Crawford, Charles L.; Wilmarth, William R.

2014-01-01

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream, LAW Off-Gas Condensate, from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of canistered glass waste forms. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to be within acceptable concentration ranges in the LAW glass. Diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the impact of potential future disposition of this stream in the Hanford tank farms, and investigates auxiliary evaporation to enable another disposition path. Unless an auxiliary evaporator is used, returning the stream to the tank farms would require evaporation in the 242-A evaporator. This stream is expected to be unusual because it will be very high in corrosive species that are volatile in the melter

Upgraded biogas from municipal solid waste for natural gas substitution and CO2 reduction – A case study of Austria, Italy, and Spain

International Nuclear Information System (INIS)

Starr, Katherine; Villalba, Gara; Gabarrell, Xavier

2015-01-01

Highlights: • Biogas can be upgraded to create biomethane, a substitute to natural gas. • Biogas upgrading was applied to landfills and anaerobic digestors in 3 countries. • Up to 0.6% of a country’s consumption of natural gas could be replaced by biomethane. • Italy could save 46% of the national CO 2 emissions attributed to the waste sector. • Scenarios were created to increase biomethane production. - Abstract: Biogas is rich in methane and can be further purified through biogas upgrading technologies, presenting a viable alternative to natural gas. Landfills and anaerobic digestors treating municipal solid waste are a large source of such biogas. They therefore offer an attractive opportunity to tap into this potential source of natural gas while at the same time minimizing the global warming impact resulting from methane emissions in waste management schemes (WMS) and fossil fuel consumption reduction. This study looks at the current municipal solid waste flows of Spain, Italy, and Austria over one year (2009), in order to determine how much biogas is generated. Then it examines how much natural gas could be substituted by using four different biogas upgrading technologies. Based on current waste generation rates, exploratory but realistic WMS were created for each country in order to maximize biogas production and potential for natural gas substitution. It was found that the potential substitution of natural gas by biogas resulting from the current WMS seems rather insignificant: 0.2% for Austria, 0.6% for Italy and 0.3% for Spain. However, if the WMS is redesigned to maximize biogas production, these figures can increase to 0.7% for Austria, 1% for Italy and 2% for Spain. Furthermore, the potential CO 2 reduction as a consequence of capturing the biogas and replacing fossil fuel can result in up to a 93% reduction of the annual national waste greenhouse gas emissions of Spain and Italy

Dose-Dependent Protective Effect of Inhalational Anesthetics Against Postoperative Respiratory Complications

DEFF Research Database (Denmark)

Grabitz, Stephanie D; Farhan, Hassan N; Ruscic, Katarina J

2017-01-01

OBJECTIVES: Inhalational anesthetics are bronchodilators with immunomodulatory effects. We sought to determine the effect of inhalational anesthetic dose on risk of severe postoperative respiratory complications. DESIGN: Prospective analysis of data on file in surgical cases between January 2007...... with endotracheal intubation. INTERVENTIONS: Median effective dose equivalent of inhalational anesthetics during surgery (derived from mean end-tidal inhalational anesthetic concentrations). MEASUREMENTS AND MAIN RESULTS: Postoperative respiratory complications occurred in 6,979 of 124,497 cases (5.61%). High...... inhalational anesthetic dose of 1.20 (1.13-1.30) (median [interquartile range])-fold median effective dose equivalent versus 0.57 (0.45-0.64)-fold median effective dose equivalent was associated with lower odds of postoperative respiratory complications (odds ratio, 0.59; 95% CI, 0.53-0.65; p

Methane gas generation from waste water extraction process of crude palm oil in experimental digesters

Science.gov (United States)

Dillon, A.; Penafiel, R.; Garzón, P. V.; Ochoa, V.

2015-12-01

Industrial processes to extract crude palm oil, generates large amounts of waste water. High concentrations of COD, ST, SV, NH4 + and low solubility of O2, make the treatment of these effluents starts with anaerobic processes. The anaerobic digestion process has several advantages over aerobic degradation: lower operating costs (not aeration), low sludge production, methane gas generation. The 4 stages of anaerobic digestion are: hydrolysis, acidogenic, acetogenesis and methanogenesis. Through the action of enzymes synthesized by microbial consortia are met. The products of each step to serve as reagents is conducted as follows. The organic load times and cell hydraulic retention, solids content, nutrient availability, pH and temperature are factors that influence directly in biodigesters. The objectives of this presentation is to; characterize the microbial inoculum and water (from palm oil wasted water) to be used in biodigestores, make specific methanogenic activity in bioassays, acclimatize the microorganisms to produce methane gas using basal mineral medium with acetate for the input power, and to determine the production of methane gas digesters high organic load.

Pilot-plant for NOx, SO2, HCl removal from flue-gas of municipal waste incinerator by electron beam irradiation

International Nuclear Information System (INIS)

Doi, Takeshi; Suda, Shoichi; Morishige, Atsushi; Tokunaga, Okihiro; Aoki, Yasushi; Sato, Shoichi; Komiya, Mikihisa; Hashimoto, Nobuo; Nakajima, Michihiro.

1992-01-01

A pilot-Plant for NO x , SO 2 and HCl removal from flue-gas of municipal waste incinerator by electron beam irradiation was designed and its construction at Matsudo City Waste Disposal Center was planned. The flue-gas of 1,000 Nm 3 /hr is guided from the waste incinerator flue-gas line of 30,000 Nm 3 /hr to the Pilot-Plant to be processed by spraying Ca(OH) 2 slurry (NKK-LIMAR Process) and irradiating high-energy electron beam of an accelerator. NO x , SO 2 and HCl are removed simultaneously from the flue-gas by the enhanced reaction with Ca(OH) 2 under irradiation. According to the basic research performed using a small size reactor at TRCRE of JAERI, the electron beam irradiation process was proved to be very effective for these harmful gases removal. Based on this result, the Pilot-Plant was designed for the demonstration of NO x , SO 2 and HCl removal performance using electron accelerator of maximum energy 0.95 MeV and maximum power 15 kW. The designing and planning were promoted by NKK in cooperation with JAERI and Matsudo City. (author)

Production and disposal of waste materials from gas and oil extraction from the Marcellus Shale Play in Pennsylvania

Science.gov (United States)

Maloney, Kelly O.; Yoxtheimer, David A.

2012-01-01

The increasing world demand for energy has led to an increase in the exploration and extraction of natural gas, condensate, and oil from unconventional organic-rich shale plays. However, little is known about the quantity, transport, and disposal method of wastes produced during the extraction process. We examined the quantity of waste produced by gas extraction activities from the Marcellus Shale play in Pennsylvania for 2011. The main types of wastes included drilling cuttings and fluids from vertical and horizontal drilling and fluids generated from hydraulic fracturing [i.e., flowback and brine (formation) water]. Most reported drill cuttings (98.4%) were disposed of in landfills, and there was a high amount of interstate (49.2%) and interbasin (36.7%) transport. Drilling fluids were largely reused (70.7%), with little interstate (8.5%) and interbasin (5.8%) transport. Reported flowback water was mostly reused (89.8%) or disposed of in brine or industrial waste treatment plants (8.0%) and largely remained within Pennsylvania (interstate transport was 3.1%) with little interbasin transport (2.9%). Brine water was most often reused (55.7%), followed by disposal in injection wells (26.6%), and then disposed of in brine or industrial waste treatment plants (13.8%). Of the major types of fluid waste, brine water was most often transported to other states (28.2%) and to other basins (9.8%). In 2011, 71.5% of the reported brine water, drilling fluids, and flowback was recycled: 73.1% in the first half and 69.7% in the second half of 2011. Disposal of waste to municipal sewage treatment plants decreased nearly 100% from the first half to second half of 2011. When standardized against the total amount of gas produced, all reported wastes, except flowback sands, were less in the second half than the first half of 2011. Disposal of wastes into injection disposal wells increased 129.2% from the first half to the second half of 2011; other disposal methods decreased. Some

Assessment of microbial processes on gas production at radioactive low-level waste disposal sites

International Nuclear Information System (INIS)

Weiss, A.J.; Tate, R.L. III; Colombo, P.

1982-05-01

Factors controlling gaseous emanations from low level radioactive waste disposal sites are assessed. Importance of gaseous fluxes of methane, carbon dioxide, and possible hydrogen from the site, stems from the inclusion of tritium and/or carbon-14 into the elemental composition of these compounds. In that the primary source of these gases is the biodegradation of organic components of the waste material, primary emphasis of the study involved an examination of the biochemical pathways producing methane, carbon dioxide, and hydrogen, and the environmental parameters controlling the activity of the microbial community involved. Initial examination of the data indicates that the ecosystem is anaerobic. As the result of the complexity of the pathway leading to methane production, factors such as substrate availability, which limit the initial reaction in the sequence, greatly affect the overall rate of methane evolution. Biochemical transformations of methane, hydrogen and carbon dioxide as they pass through the soil profile above the trench are discussed. Results of gas studies performed at three commercial low level radioactive waste disposal sites are reviewed. Methods used to obtain trench and soil gas samples are discussed. Estimates of rates of gas production and amounts released into the atmosphere (by the GASFLOW model) are evaluated. Tritium and carbon-14 gaseous compounds have been measured in these studies; tritiated methane is the major radionuclide species in all disposal trenches studied. The concentration of methane in a typical trench increases with the age of the trench, whereas the concentration of carbon dioxide is similar in all trenches

Laboratory Scoping Tests Of Decontamination Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, Kathryn M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nash, Charles A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, Charles L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); McCabe, Daniel J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Wilmarth, William R. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2014-01-21

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task seeks to examine the potential treatment of this stream to remove radionuclides and subsequently disposition the decontaminated stream elsewhere, such as the Effluent Treatment Facility (ETF), for example. The treatment process envisioned is very similar to that used for the Actinide Removal Process (ARP) that has been operating for years at the Savannah River Site (SRS), and focuses on using mature radionuclide removal technologies that are also

Anesthetic neuroprotection: antecedents and an appraisal of preclinical and clinical data quality.

Science.gov (United States)

Ishida, Kazuyoshi; Berger, Miles; Nadler, Jacob; Warner, David S

2014-01-01

Anesthetics have been studied for nearly fifty years as potential neuroprotective compounds in both perioperative and resuscitation medicine. Although anesthetics present pharmacologic properties consistent with preservation of brain viability in the context of an ischemic insult, no anesthetic has been proven efficacious for neuroprotection in humans. After such effort, it could be concluded that anesthetics are simply not neuroprotective in humans. Moreover, pharmacologic neuroprotection with non-anesthetic drugs has also repeatedly failed to be demonstrated in human acute brain injury. Recent focus has been on rectification of promising preclinical neuroprotection data and subsequent failed clinical trials. This has led to consensus guidelines for the process of transferring purported therapeutics from bench to bedside. In this review we first examined the history of anesthetic neuroprotection research. Then, a systematic review was performed to identify major clinical trials of anesthetic neuroprotection. Both the preclinical neuroprotection portfolio cited to justify a clinical trial and the design and conduct of that clinical trial were evaluated using modern standards that include the Stroke Therapy Academic Industry Roundtable (STAIR) and Consolidated Standards of Reporting Trials (CONSORT) guidelines. In publications intended to define anesthetic neuroprotection, we found overall poor quality of both preclinical efficacy analysis portfolios and clinical trial designs and conduct. Hence, using current translational research standards, it was not possible to conclude from existing data whether anesthetics ameliorate perioperative ischemic brain injury. Incorporation of advances in translational neuroprotection research conduct may provide a basis for more definitive and potentially successful clinical trials of anesthetics as neuroprotectants.

Cell shape changes induced by cationic anesthetics

Science.gov (United States)

1976-01-01

The effects of local anesthetics on cultivated macrophages were studied in living preparations and recorded in still pictures and time-lapse cine-micrographs. Exposure to 12mM lidocaine or 1.5 mM tetracaine resulted in rounding in 10-15 min. Rounding was characterized by cell contraction, marked increase in retraction fibrils, withdrawal of cell processes, and, in late stages, pulsation-like activity and zeiosis. Cells showed appreciable membrane activity as they rounded. Respreading was complete within 15 min of perfusion in drug-free medium and entailed a marked increase in surface motility over control periods. As many as eight successive cycles of rounding and spreading were obtained with lidocaine without evidence of cell damage. The effects of anesthetics were similar to those observed with EDTA, but ethylene- glycol-bis(beta-aminoethylether)-N, N'-tetraacetic acid-Mg was ineffective. Rounding was also induced by benzocaine, an anesthetic nearly uncharged at pH 7.0. Quaternary (nondischargeable) compounds were of low activity, presumably because they are slow permeants. Lidocaine induced rounding at 10 degrees C and above but was less effective at 5 degrees C and ineffective at 0 degrees C. Rounding by the anesthetic was also obtained in media depleted or Na or enriched with 10 mM Ca or Mg. The latter finding, together with the failure of tetrodotoxin to induce rounding, suggests that the anesthetic effect is unrelated to inhibition of sodium conductance. It is possible that the drugs influence divalent ion fluxes or some component of the contractile cells' machinery, but a metabolic target of action cannot yet be excluded. PMID:814194

ANESTHETIC MANAGEMENT FOR A PATIENT WITH ACUTE INTERMITTENT PORPHYRIA

Directory of Open Access Journals (Sweden)

Nenad Savić

2010-09-01

Full Text Available Acute intermittent porphyria is a rare metabolic disorder resulting from a partial deficiency of porphobilinogen deaminase, enzyme in the heme biosynthetic pathway. Its inheritance is autosomal dominant. A deficiency of porphobilinogen deaminase is not sufficient by its self to produce acute intermittent porphyria, and other activating factors must also be present. These include some drugs, hormones, infection, injury and alcohol. Besides others, anesthetics have been implicated in the triggering of a number of severe porphyric reactions. Although there is no clinical evidence, the fear of hypothesized porphyrinogenicity of repetitive anesthetics exposures still remains. Despite these doubts, we report here the case of uneventful repeated exposure to anesthetics in a patient suffering from acute intermittent porphyria, within a fifteen- month period. On both occasions, the patient was safely exposed to certain anesthetics included: propofol, sevoflurane, rocuronium, midazolam and fentanyl.

Analysis of Indirect Emissions Benefits of Wind, Landfill Gas, and Municipal Solid Waste Generation

Science.gov (United States)

Techniques are introduced to calculate the hourly indirect emissions benefits of three types of green power resources: wind energy, municipal solid waste (MSW) combustion, and landfill gas (LFG) combustion. These techniques are applied to each of the U.S. EPA's eGRID subregions i...

Life cycle greenhouse gas impacts of ethanol, biomethane and limonene production from citrus waste

Science.gov (United States)

Pourbafrani, Mohammad; McKechnie, Jon; MacLean, Heather L.; Saville, Bradley A.

2013-03-01

The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA�

Life cycle greenhouse gas impacts of ethanol, biomethane and limonene production from citrus waste

International Nuclear Information System (INIS)

Pourbafrani, Mohammad; MacLean, Heather L; Saville, Bradley A; McKechnie, Jon

2013-01-01

The production of biofuel from cellulosic residues can have both environmental and financial benefits. A particular benefit is that it can alleviate competition for land conventionally used for food and feed production. In this research, we investigate greenhouse gas (GHG) emissions associated with the production of ethanol, biomethane, limonene and digestate from citrus waste, a byproduct of the citrus processing industry. The study represents the first life cycle-based evaluations of citrus waste biorefineries. Two biorefinery configurations are studied—a large biorefinery that converts citrus waste into ethanol, biomethane, limonene and digestate, and a small biorefinery that converts citrus waste into biomethane, limonene and digestate. Ethanol is assumed to be used as E85, displacing gasoline as a light-duty vehicle fuel; biomethane displaces natural gas for electricity generation, limonene displaces acetone in solvents, and digestate from the anaerobic digestion process displaces synthetic fertilizer. System expansion and two allocation methods (energy, market value) are considered to determine emissions of co-products. Considerable GHG reductions would be achieved by producing and utilizing the citrus waste-based products in place of the petroleum-based or other non-renewable products. For the large biorefinery, ethanol used as E85 in light-duty vehicles results in a 134% reduction in GHG emissions compared to gasoline-fueled vehicles when applying a system expansion approach. For the small biorefinery, when electricity is generated from biomethane rather than natural gas, GHG emissions are reduced by 77% when applying system expansion. The life cycle GHG emissions vary substantially depending upon biomethane leakage rate, feedstock GHG emissions and the method to determine emissions assigned to co-products. Among the process design parameters, the biomethane leakage rate is critical, and the ethanol produced in the large biorefinery would not meet EISA�

The importance of solid waste management and its reverse logistics in fuel gas city of Campina Grande – PB

Directory of Open Access Journals (Sweden)

Joselia Fernandes Nascimento

2016-04-01

Full Text Available This research aimed to identify the importance of controlling the solid waste management process generated in the posts of Campina Grande-PB fuels, still checking the current level of adequacy of the same with respect to Reverse Logistics for the proper disposal of lubricating oils used and / or contaminated, their waste and packaging. The population consisted of 56 gas stations, authorized by the National Agency of Petroleum, Natural Gas and Biofuels (ANP, and resulted in a sample, for this study, 35 stations, representing 62.50% of the universe. Data collection was carried out with the use of questionnaires and research is characterized exploratory and descriptive. The results show that 51.43% of respondents know the important role of controlling, but most do not have enough knowledge regarding PNRS, LR and management of solid waste, however, has actions that are appropriate for the proper disposal waste.

Tolerance to acute isovolemic hemodilution. Effect of anesthetic depth

NARCIS (Netherlands)

van der Linden, Philippe; de Hert, Stefan; Mathieu, Nathalie; Degroote, Françoise; Schmartz, Denis; Zhang, Haibo; Vincent, Jean-Louis

2003-01-01

BACKGROUND: Acceptance of a lower transfusion trigger in the perioperative period requires study of the effects of anesthetic depth on the tolerance to acute isovolemic anemia. Anesthetic agents with negative effects on the cardiovascular system may exert proportionately greater depressant effects

Toxic keratopathy due to abuse of topical anesthetic drugs.

Science.gov (United States)

Yeniad, Baris; Canturk, Serife; Esin Ozdemir, Fatma; Alparslan, Nilufer; Akarcay, Koray

2010-06-01

To describe 8 cases of toxic keratopathy due to abuse of topical anesthetic drugs. Clinical findings from patients with toxic keratopathy were investigated retrospectively. Two patients had toxic keratopathy bilaterally. Five of 8 patients had an ocular history of a corneal foreign body, 1 had basal membrane dystrophy, 1 had ultraviolet radiation, and 1 had chemical burn. All patients had undergone psychiatric consultation. Four patients had anxiety disorder and 1 had bipolar disease. Clinical signs were improved in all patients with discontinuation of topical anesthetic drug use along with adjunctive psychiatric treatment. Penetrating keratoplasty was performed in 2 patients. Toxic keratopathy due to topical anesthetic abuse is a curable disease. Early diagnosis and prevention of topical anesthetic drug use are the most important steps in the treatment of this condition. As these patients commonly exhibit psychiatric disorders, adjunctive psychiatric treatment may help to break the chemical addiction.

Probabilistic modelling of gas generation in nuclear waste repositories under consideration of new studies performed at the WIPP

International Nuclear Information System (INIS)

Niemeyer, M.; Wilhelm, S.; Poppei, J.

2012-01-01

Document available in extended abstract form only. The inventory of a nuclear waste repository includes significant amounts of metal and organic matter. Under the prevailing conditions in a repository in a salt formation in contact with water, these materials tend to react and transform under significant gas production. This increases the pressure and potentially leads to an enhanced transport of radio nuclides. Therefore, these phenomena need to be understood and characterized in detail for the assessment of the safety of the repository A modelling code, GASGEN, developed by AF-Consult Switzerland Ltd to predict the evolution of gas production by microbial processes and anaerobic corrosion of metal, was applied at two locations of repositories in salt rock in Germany. Therein, the microbial decomposition of organic waste components is modelled by the sub-processes of denitrification, reduction of sulphates, fermentation and methano-genesis. The models differentiate between highly degradable cellulose and materials of lesser degradability, such as polymers. Gas production through anaerobic corrosion of metal is mainly due to the iron content of the waste. In addition, the precipitation of carbonate from alkaline materials in the inventory (e.g. cement) is considered. The inventories of contained waste, which determine the amount of gas that can be produced, are subject to uncertainties. The rates of the various reactions also depend on numerous factors and are therefore variable. In order to cover this variability, gas production is modelled probabilistically. In this way the behaviour of the gas generation can be estimated together with its bandwidth Figure 1. In addition to the produced amounts of gas, the model calculations also consider the potential of acidification of the fluid enclosed in the repository chambers and the effect of a changing pH-level on the rate of corrosion. Based on results, the effect of a pH-dependent corrosion rate is illustrated and the

Natural gas storage in microporous carbon obtained from waste of the olive oil production

Directory of Open Access Journals (Sweden)

Cecilia Solar

2008-12-01

Full Text Available A series of activated carbons (AC were prepared from waste of the olive oil production in the Cuyo Region, Argentine by two standard methods: a physical activation by steam and b chemical activation with ZnCl2. The AC samples were characterized by nitrogen adsorption at 77 K and evaluated for natural gas storage purposes through the adsorption of methane at high pressures. The activated carbons showed micropore volumes up to 0.50 cm³.g-1 and total pore volumes as high as 0.9 cm³.g-1. The BET surface areas reached, in some cases, more than 1000 m².g-1. The methane adsorption -measured in the range of 1-35 bar- attained values up to 59 V CH4/V AC and total uptakes of more than 120 cm³.g-1 (STP. These preliminary results suggest that Cuyo's olive oil waste is appropriate for obtaining activated carbons for the storage of natural gas.

Technologies for gas cooled reactor decommissioning, fuel storage and waste disposal. Proceedings of a technical committee meeting

International Nuclear Information System (INIS)

1998-09-01

Gas cooled reactors (GCRs) and other graphite moderated reactors have been important part of the world's nuclear programme for the past four decades. The wide diversity in status of this very wide spectrum of plants from initial design to decommissioning was a major consideration of the International Working group on Gas Cooled Reactors which recommended IAEA to convene a Technical Committee Meeting dealing with GCR decommissioning, including spent fuel storage and radiological waste disposal. This Proceedings includes papers 25 papers presented at the Meeting in three sessions entitled: Status of Plant Decommissioning Programmes; Fuels Storage Status and Programmes; waste Disposal and decontamination Practices. Each paper is described here by a separate abstract

Gaseous radioactive waste processing system

International Nuclear Information System (INIS)

Onizawa, Hideo.

1976-01-01

Object: To prevent explosion of hydrogen gas within gaseous radioactive waste by removing the hydrogen gas by means of a hydrogen absorber. Structure: A coolant extracted from a reactor cooling system is sprayed by nozzle into a gaseous phase (hydrogen) portion within a tank, thus causing slipping of radioactive rare gas. The gaseous radioactive waste rich in hydrogen, which is purged in the tank, is forced by a waste gas compressor into a hydrogen occlusion device. The hydrogen occlusion device is filled with hydrogen occluding agents such as Mg, Mg-Ni alloy, V-Nb alloy, La-Ni alloy and so forth, and hydrogen in the waste gas is removed through reaction to produce hydrogen metal. The gaseous radioactive waste, which is deprived of hydrogen and reduced in volume, is stored in an attenuation tank. The hydrogen stored in the hydrogen absorber is released and used again as purge gas. (Horiuchi, T.)

Scientometrics of anesthetic drugs and their techniques of administration, 1984–2013

Directory of Open Access Journals (Sweden)

Vlassakov KV

2014-12-01

Full Text Available Kamen V Vlassakov, Igor Kissin Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, USA Abstract: The aim of this study was to assess progress in the field of anesthetic drugs over the past 30 years using scientometric indices: popularity indices (general and specific, representing the proportion of articles on a drug relative to all articles in the field of anesthetics (general index or the subfield of a specific class of anesthetics (specific index; index of change, representing the degree of growth in publications on a topic from one period to the next; index of expectations, representing the ratio of the number of articles on a topic in the top 20 journals relative to the number of articles in all (>5,000 biomedical journals covered by PubMed; and index of ultimate success, representing a publication outcome when a new drug takes the place of a common drug previously used for the same purpose. Publications on 58 topics were assessed during six 5-year periods from 1984 to 2013. Our analysis showed that during 2009–2013, out of seven anesthetics with a high general popularity index (≥2.0, only two were introduced after 1980, ie, the inhaled anesthetic sevoflurane and the local anesthetic ropivacaine; however, only sevoflurane had a high index of expectations (12.1. Among anesthetic adjuncts, in 2009–2013, only one agent, sugammadex, had both an extremely high index of change (>100 and a high index of expectations (25.0, reflecting the novelty of its mechanism of action. The index of ultimate success was positive with three anesthetics, ie, lidocaine, isoflurane, and propofol, all of which were introduced much longer than 30 years ago. For the past 30 years, there were no new anesthetics that have produced changes in scientometric indices indicating real progress. Keywords: anesthetics, anesthetic adjuvants, mortality, safety margins, therapeutic indices

Processing mixed-waste compressed-gas cylinders at the Oak Ridge Reservation

International Nuclear Information System (INIS)

Morris, M.I.; Conley, T.B.; Osborne-Lee, I.W.

1998-05-01

Until recently, several thousand kilograms of compressed gases were stored at the Oak Ridge Reservation (ORR), in Oak Ridge, Tennessee, because these cylinders could not be taken off-site in their state of configuration for disposal. Restrictions on the storage of old compressed-gas cylinders compelled the Waste Management Organization of Lockheed Martin Energy Systems, Inc. (LMES) to dispose of these materials. Furthermore, a milestone in the ORR Site Treatment Plan required repackaging and shipment off-site of 21 cylinders by September 30, 1997. A pilot project, coordinated by the Chemical Technology Division (CTD) at the Oak Ridge National Laboratory (ORNL), was undertaken to evaluate and recontainerize or neutralize these cylinders, which are mixed waste, to meet that milestone. Because the radiological component was considered to be confined to the exterior of the cylinder, the contents (once removed from the cylinder) could be handled as hazardous waste, and the cylinder could be handled as low-level waste (LLW). This pilot project to process 21 cylinders was important because of its potential impact. The successful completion of the project provides a newly demonstrated technology which can now be used to process the thousands of additional cylinders in inventory across the DOE complex. In this paper, many of the various aspects of implementing this project, including hurdles encountered and the lessons learned in overcoming them, are reported

Upgraded biogas from municipal solid waste for natural gas substitution and CO{sub 2} reduction – A case study of Austria, Italy, and Spain

Energy Technology Data Exchange (ETDEWEB)

Starr, Katherine [Sostenipra, Department of Chemical Engineering, Universitat Autonoma de Barcelona, Bellaterra (Spain); Villalba, Gara, E-mail: gara.villalba@uab.es [Sostenipra, Department of Chemical Engineering, Universitat Autonoma de Barcelona, Bellaterra (Spain); Sostenipra, Institute de Ciencia i Technologia Ambientals (ICTA), Universitat Autonoma de Barcelona, Bellaterra (Spain); Gabarrell, Xavier [Sostenipra, Department of Chemical Engineering, Universitat Autonoma de Barcelona, Bellaterra (Spain); Sostenipra, Institute de Ciencia i Technologia Ambientals (ICTA), Universitat Autonoma de Barcelona, Bellaterra (Spain)

2015-04-15

Highlights: • Biogas can be upgraded to create biomethane, a substitute to natural gas. • Biogas upgrading was applied to landfills and anaerobic digestors in 3 countries. • Up to 0.6% of a country’s consumption of natural gas could be replaced by biomethane. • Italy could save 46% of the national CO{sub 2} emissions attributed to the waste sector. • Scenarios were created to increase biomethane production. - Abstract: Biogas is rich in methane and can be further purified through biogas upgrading technologies, presenting a viable alternative to natural gas. Landfills and anaerobic digestors treating municipal solid waste are a large source of such biogas. They therefore offer an attractive opportunity to tap into this potential source of natural gas while at the same time minimizing the global warming impact resulting from methane emissions in waste management schemes (WMS) and fossil fuel consumption reduction. This study looks at the current municipal solid waste flows of Spain, Italy, and Austria over one year (2009), in order to determine how much biogas is generated. Then it examines how much natural gas could be substituted by using four different biogas upgrading technologies. Based on current waste generation rates, exploratory but realistic WMS were created for each country in order to maximize biogas production and potential for natural gas substitution. It was found that the potential substitution of natural gas by biogas resulting from the current WMS seems rather insignificant: 0.2% for Austria, 0.6% for Italy and 0.3% for Spain. However, if the WMS is redesigned to maximize biogas production, these figures can increase to 0.7% for Austria, 1% for Italy and 2% for Spain. Furthermore, the potential CO{sub 2} reduction as a consequence of capturing the biogas and replacing fossil fuel can result in up to a 93% reduction of the annual national waste greenhouse gas emissions of Spain and Italy.

FY 1992 report on the development of wood-waste/agri-waste pyrolytic gasification technology and utilization technology of gas product; 1992 nendo mokushitsukei haikibutsu no netsubunkai gas ka gijutsu to seisei gas no riyo gijutsu kaihatsu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-03-01

It is urgently necessary for the Philippines, which has no promising energy source to replace imported oil and lacks hard currencies, to reduce dependence on oil. The country, consisting of a number of islands, has faced many difficulties in construction of large-scale power transmission grids covering wide areas, which greatly retard development of local industries and dissemination of electricity. Therefore, great expectations have been placed on the techniques this project plans to develop for utilization of wastes as the energy source. This 5-year project (FY 1990 to 1994) is aimed at joint research and development of (thermal decomposition/gasification and power generation system) for transforming large quantities of wood-wastes/agri-wastes left unutilized into electric power, in which thermal decomposition/gasification of the wastes is combined with gas engine/power generator systems, and thereby to establish the systems suitable for the developing country. The major R and D results obtained in FY 1992 as the third year include on-the-spot surveys, tests for validating elementary techniques, designs and fabrication of part of the demonstration plant, and invitation of Philippine researchers to Japan. (NEDO)

FY 1991 report on the development of wood-waste/agri-waste pyrolytic gasification technology and utilization technology of gas product; 1991 nendo mokushitsukei haikibutsu no netsubunkai gas ka gijutsu to seisei gas no riyo gijutsu kaihatsu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-03-01

It is urgently necessary for the Philippines, which has no promising energy source to replace imported oil and lacks hard currencies, to reduce dependence on oil. The country, consisting of a number of islands, has faced many difficulties in construction of large-scale power transmission grids covering wide areas, which greatly retard development of local industries and dissemination of electricity. Therefore, great expectations have been placed on the techniques this project plans to develop for utilization of wastes as the energy source. This 5-year project (FY 1990 to 1994) is aimed at joint research and development of (thermal decomposition/gasification and power generation system) for transforming large quantities of wood-wastes/agri-wastes left unutilized into electric power, in which thermal decomposition/gasification of the wastes is combined with gas engine/power generator systems, and thereby to establish the systems suitable for the developing country. The major R and D results obtained in FY 1991 as the second year include on-the-spot surveys, tests for validating elementary techniques, designs and fabrication of part of the demonstration plant, and invitation of Philippine researchers to Japan. (NEDO)

FY 1990 report on the development of wood-waste/agri-waste pyrolytic gasification technology and utilization technology of gas product; 1990 nendo mokushitsukei haikibutsu no netsubunkai gas ka gijutsu to seisei gas no riyo gijutsu kaihatsu hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-03-01

It is urgently necessary for the Philippines, which has no promising energy source to replace imported oil and lacks hard currencies, to reduce dependence on oil. The country, consisting of a number of islands, has faced many difficulties in construction of large-scale power transmission grids covering wide areas, which greatly retard development of local industries and dissemination of electricity. Therefore, great expectations have been placed on the techniques this project plans to develop for utilization of wastes as the energy source. This 5-year project (FY 1990 to 1994) is aimed at joint research and development of (thermal decomposition/gasification and power generation system) for transforming large quantities of wood-wastes/agri-wastes left unutilized into electric power, in which thermal decomposition/gasification of the wastes is combined with gas engine/power generator systems, and thereby to establish the systems suitable for the developing country. The major R and D results obtained in FY 1990 as the initial year include negotiations with the Philippines, on-the-spot surveys for the demonstration plant sites and conditions, and conceptual designs of the demonstration plant. (NEDO)

Organic compound emissions from a landfarm used for oil and gas solid waste disposal.

Science.gov (United States)

Lyman, Seth N; Mansfield, Marc L

2018-04-13

Solid or sludgy hydrocarbon waste is a by-product of oil and gas exploration and production. One commonly used method of disposing of this waste is landfarming. Landfarming involves spreading hydrocarbon waste on soils, tilling it into the soil, and allowing it to biodegrade. We used a dynamic flux chamber to measure fluxes of methane, a suite of 54 nonmethane hydrocarbons, and light alcohols from an active and a remediated landfarm in eastern Utah. Fluxes from the remediated landfarm were not different from a polytetrafluoroethylene (PTFE) sheet or from undisturbed soils in the region. Fluxes of methane, total nonmethane hydrocarbons, and alcohols from the landfarm in active use were 1.41 (0.37, 4.19) (mean and 95% confidence limits), 197.90 (114.72, 370.46), and 4.17 (0.03, 15.89) mg m -2  hr -1 , respectively. Hydrocarbon fluxes were dominated by alkanes, especially those with six or more carbons. A 2-ha landfarm with fluxes of the magnitude we observed in this study would emit 95.3 (54.3, 179.7) kg day -1 of total hydrocarbons, including 11.2 (4.3, 33.9) kg day -1 of BTEX (benzene, toluene, ethylbenzene, and xylenes). Solid and sludgy hydrocarbon waste from the oil and gas industry is often disposed of by landfarming, in which wastes are tilled into soil and allowed to decompose. We show that a land farm in Utah emitted a variety of organic compounds into the atmosphere, including hazardous air pollutants and compounds that form ozone. We calculate that a 2-ha landfarm facility would emit 95.0 ± 66.0 kg day -1 of total hydrocarbons, including 11.1 ± 1.5 kg day -1 of BTEX (benzene, toluene, ethylbenzene, and xylenes).

Radiation Protection and the Management of Radioactive Waste in the Oil and Gas Industry

International Nuclear Information System (INIS)

2010-01-01

The oil and gas industry, a global industry operating in many Member States, makes extensive use of radiation generators and sealed and unsealed radioactive sources, some of which are potentially dangerous to human health and the environment if not properly controlled. In addition, significant quantities of naturally occurring radioactive material (NORM) originating from the reservoir rock are encountered during production, maintenance and decommissioning. The oil and gas industry operates in all climates and environments, including the most arduous conditions, and is continuously challenged to achieve high efficiency of operation while maintaining a high standard of safety and control - this includes the need to maintain control over occupational exposures to radiation, as well as to protect the public and the environment through proper management of wastes that may be radiologically and chemically hazardous. The oil and gas industry is organizationally and technically complex, and relies heavily on specialized service and supply companies to provide the necessary equipment and expertise, including expertise in radiation safety. This training manual is used by the IAEA as the basis for delivering its training course on radiation protection and the management of radioactive waste in the oil and gas industry. Enclosed with this manual is a CD-ROM that contains the presentational material used in the training course, the course syllabus and additional notes for course presenters. The course material is based principally on IAEA Safety Reports Series No. 34 Radiation Protection and the Management of Radioactive Waste in the Oil and Gas Industry, published by the IAEA in 2003. The training course is aimed at regulatory bodies; oil and gas field operators and support companies; workers and their representatives; health, safety and environmental professionals; and health and safety training officers. A pilot training course was held in the Syrian Arab Republic in 2000 as

Methodology for flammable gas evaluations

Energy Technology Data Exchange (ETDEWEB)

Hopkins, J.D., Westinghouse Hanford

1996-06-12

There are 177 radioactive waste storage tanks at the Hanford Site. The waste generates flammable gases. The waste releases gas continuously, but in some tanks the waste has shown a tendency to trap these flammable gases. When enough gas is trapped in a tank`s waste matrix, it may be released in a way that renders part or all of the tank atmosphere flammable for a period of time. Tanks must be evaluated against previously defined criteria to determine whether they can present a flammable gas hazard. This document presents the methodology for evaluating tanks in two areas of concern in the tank headspace:steady-state flammable-gas concentration resulting from continuous release, and concentration resulting from an episodic gas release.

Corrosion in the off-gas system of a radioactive-waste incinerator

International Nuclear Information System (INIS)

Jenkins, C.F.; Peters, J.J.

1987-01-01

Corrosion in a low-level radioactive-waste incinerator off-gas system at the Department of Energy's Savannah River Plant is discussed. Severe corrosive attack and failure of an alloy 600 part exposed to high-temperature (>1000 0 C) gases was observed. Rapid attack of carbon steel components, and cracking of austenitic stainless steel parts also occurred at locations where lower gas temperatures and periodic condensate exposure occurred. Investigation showed HCl, SO 2 , SO 3 and phosphorus-oxides were present and contributed to the failures. Mechanisms of high-temperature failure include alloy separation and reactions with phosphorus. Coupons placed in the exhaust stream have provided information for selection of future materials of construction for system components. Several nickel- and iron-base alloys, and a stainless steel with an aluminum-diffusion coating were investigated

Experiments on the possible usage of liquid industrial wastes from a paint and lacquer factory for flue gas desulphurization

Energy Technology Data Exchange (ETDEWEB)

Trzepierczynska, I.; Lech-Brzyk, K. [Technical University of Wroclaw, Wroclaw (Poland). Inst. of Environment Protection Engineering

1995-12-31

In this paper, the complex solution of environment protection against flue gases (comprising sulphur dioxide) and alkaline industrial wastewater is provided. Industrial wastes from a paint and lacquer factory were examined and their usage for sulphur dioxide absorption was determined. The combined method of alkaline waste neutralization and flue gas desulphurization is proposed. The liquid wastes come from the POLIFARB SA plant in Wroclaw. 9 refs., 7 tabs.

Evaluation of local anesthetic and antipyretic activities of Cinchona ...

African Journals Online (AJOL)

Purpose: To evaluate the local anesthetic and antipyretic activities of an aqueous extract of Cinchona officinalis (C. officinalis) in experimental animal models. Methods: Various doses of the aqueous extract was tested for its local anesthetic activity in guinea pigs and frogs using intracutaneous and plexus anesthesia, ...

Co-pyrolysis of waste tire/coal mixtures for smokeless fuel, maltenes and hydrogen-rich gas production

International Nuclear Information System (INIS)

Bičáková, Olga; Straka, Pavel

2016-01-01

Highlights: • Co-pyrolysis of waste tires/coal mixtures yields mainly smokeless fuel (55–74 wt%). • Alternatively, the smokeless fuel can serve as carbonaceous sorbent. • The obtained tar contained maltenes (80–85 wt%) and asphaltenes (6–8 wt%). • Tar from co-pyrolysis can serve as heating oil or a source of maltenes for repairing of asphalt surfaces. • The hydrogen-rich gas was obtained (61–65 vol% H_2, 24–25 vol% CH_4, 1.4–2 vol% CO_2). - Abstract: The processing of waste tires with two different types of bituminous coal was studied through the slow co-pyrolysis of 1 kg of waste tire/coal mixtures with 15, 30 and 60 wt% waste tires on a laboratory scale. The waste tire/coal mixtures were pyrolysed using a quartz reactor in a stationary bed. The mixtures were heated at a rate 5 °C/min up to the final temperature of 900 °C with a soaking time of 30 min at the required temperature. The mass balance of the process and the properties of the coke and tar obtained were evaluated, further, the influence of the admixture in the charge on the amount and composition of the obtained coke and tar was determined. It was found that the smokeless fuel/carbonaceous sorbent and a high yield of tar for further use can be obtained through the slow co-pyrolysis. The obtained tars contained mostly maltenes (80–85 wt%). FTIR analysis showed that the maltenes from the co-pyrolysis of coal/waste tires exhibited significantly lower aromaticity as compared with that from coal alone. The gas obtained from pyrolysis or co-pyrolysis of waste tire/coal mixtures contained a high amount of hydrogen (above 60 vol%) and methane (above 20 vol%).

Positional Arrangements of Waste Exhaust Gas Ducts of C-Type Balanced Chimney Heating Devices on Building Façades

Directory of Open Access Journals (Sweden)

Erkan AVLAR

2009-01-01

Full Text Available In Turkey today, with the increase in availability of natural gas,detached heating devices are being preferred over existingheating devices. Due to the lack of chimneys in existing buildingsin Turkey or the presence of chimneys that fail to conformto standards, the use of C-type balanced chimney devices has increased.C-type balanced chimney devices take the combustionair directly from the outside by a specific air duct as detachedheating equipment, with enclosed combustion chambers anda specific waste gas exhaust duct, and they are ventilated independentlyof the field of equipment. Because of their essentiality,the use of a chimney is not required in these devices;the waste gas is exhausted through walls, windows, doors, orbalconies. The natural gas is a clean fossil fuel that requires nostorage in buildings and is easy to use. However, water vapor,carbon dioxide and nitrogen oxides are produced by the combustionof natural gas. It is widely known that high concentrationsof these products can have some adverse effects onhumans such as dizziness, headaches and nausea. As a result,the waste products could recoil through wall openings on thefaçade to create unhealthy indoor environments that could bedangerous to human health. Therefore, the importance of standardsand regulations about the positional arrangements of thewaste gas exhaust ducts of C-type balanced chimney devices onbuilding façades is increasing. In this research, we analyze thestudies of the Institution of Turkish Standards, Chamber of MechanicalEngineers, gas distribution companies, municipalitiesand authorized firms and compare the criteria to determine thenecessary application method. According to our comparison ofthe references accessed, the criteria are not uniform.

Release to the gas phase of metals, S and Cl during combustion of dedicated waste fractions

DEFF Research Database (Denmark)

Pedersen, Anne Juul; van Lith, Simone Cornelia; Frandsen, Flemming

2010-01-01

The release to the gas phase of inorganic elements such as alkali metals. Cl, S, and heavy metals in Waste-to-Energy (WtE) boilers is a challenge. Besides the risk of harmful emissions to the environment, inorganic elements released from the grate may cause severe ash deposition and corrosion...... and the link to the formation of fly ash and aerosols in full-scale waste incinerators. The release of metals, S and Cl from four dedicated waste fractions was quantified as a function of temperature in a lab-scale fixed-bed reactor. The waste fractions comprised chromated copper arsenate (CCA) impregnated....... The lab-scale release results were then compared with results from a related, full-scale partitioning study, in which test runs with the addition of similar, dedicated waste fractions to a base-load waste had been performed in a grate-fired WtE boiler. In general, the elements Al, Ca, Cr, Cu, Fe, Mg, Si...

METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

Energy Technology Data Exchange (ETDEWEB)

WEBER RA

2009-01-16

The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient potential energy to break up material and release gas and are assigned to waste group B. These tanks are considered to represent a potential induced flammable gas release hazard, but no spontaneous buoyant displacement flammable gas release hazard. Tanks that are not waste group C tanks and have an energy ratio {ge} 3.0, but that pass the third criterion (buoyancy ratio < 1.0, see below) are also assigned to waste group B. Even though the designation as

METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

Energy Technology Data Exchange (ETDEWEB)

FOWLER KD

2007-12-27

This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 7 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs. The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. The first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient

R and D for an off-gas treatment system for a slagging pyrolysis radioactive waste incinerator. Final report for Phase I

International Nuclear Information System (INIS)

Christian, J.D.; Kirstein, B.E.; Pence, D.T.

1978-01-01

Preliminary evaluations were made of off-gas treatment needs for a slagging pyrolysis incinerator (SPI) of Andco--Torrax design for the treatment of radioactive waste at the INEL. Approximate decontamination factors (DFs) for particulates of 10 7 and for volatilized radionuclides of 10 3 will be required across the off-gas system. If lead is present in the waste at concentrations greater than 25-to-120 g/metric ton, volatilized lead will result in formation of substantial deposits in the off-gas system and regenerative towers. A review was made of radioactive incinerator development. Particulate and volatile component removal mechanisms and devices were reviewed. Three off-gas treatment systems were proposed for the SPI which will provide DFs for particulates of 10 8 . 9 figures, 7 tables

Emissions from US waste collection vehicles

International Nuclear Information System (INIS)

Maimoun, Mousa A.; Reinhart, Debra R.; Gammoh, Fatina T.; McCauley Bush, Pamela

2013-01-01

Highlights: ► Life-cycle emissions for alternative fuel technologies. ► Fuel consumption of alternative fuels for waste collection vehicles. ► Actual driving cycle of waste collection vehicles. ► Diesel-fueled waste collection vehicle emissions. - Abstract: This research is an in-depth environmental analysis of potential alternative fuel technologies for waste collection vehicles. Life-cycle emissions, cost, fuel and energy consumption were evaluated for a wide range of fossil and bio-fuel technologies. Emission factors were calculated for a typical waste collection driving cycle as well as constant speed. In brief, natural gas waste collection vehicles (compressed and liquid) fueled with North-American natural gas had 6–10% higher well-to-wheel (WTW) greenhouse gas (GHG) emissions relative to diesel-fueled vehicles; however the pump-to-wheel (PTW) GHG emissions of natural gas waste collection vehicles averaged 6% less than diesel-fueled vehicles. Landfill gas had about 80% lower WTW GHG emissions relative to diesel. Biodiesel waste collection vehicles had between 12% and 75% lower WTW GHG emissions relative to diesel depending on the fuel source and the blend. In 2011, natural gas waste collection vehicles had the lowest fuel cost per collection vehicle kilometer travel. Finally, the actual driving cycle of waste collection vehicles consists of repetitive stops and starts during waste collection; this generates more emissions than constant speed driving

Physiologically available cyanide (PAC) in manufactured gas plant waste and soil samples

International Nuclear Information System (INIS)

Magee, B.; Taft, A.; Ratliff, W.; Kelley, J.; Sullivan, J.; Pancorbo, O.

1995-01-01

Iron-complexed cyanide compounds, such as ferri-ferrocyanide (Prussian Blue), are wastes associated with former manufactured gas plant (MGP) facilities. When tested for total cyanide, these wastes often show a high total cyanide content. Because simple cyanide salts are acutely toxic, cyanide compounds can be the subject of concern. However, Prussian Blue and related species are known to have a low order of human and animal toxicity. Toxicology data on complexed cyanides will be presented. Another issue regarding Prussian Blue and related species is that the total cyanide method does not accurately represent the amount of free cyanide released from these cyanide species. The method involves boiling the sample in an acidic solution under vacuum to force the formation of HCN gas. Thus, Prussian Blue, which is known to be low in toxicity, cannot be properly evaluated with current methods. The Massachusetts Natural Gas Council initiated a program with the Massachusetts Department of Environmental Protection to develop a method that would define the amount of cyanide that is able to be converted into hydrogen cyanide under the pH conditions of the stomach. It is demonstrated that less than 1% of the cyanide present in Prussian Blue samples and soils from MGP sites can be converted to HCN under the conditions of the human stomach. The physiologically available cyanide method has been designed to be executed at a higher temperature for one hour. It is shown that physiologically available cyanide in MGP samples is < 5--15% of total cyanide

Foaming and Antifoaming and Gas Entrainment in Radioactive Waste Pretreatment and Immobilization Processes. Final Report

International Nuclear Information System (INIS)

Wasan, Darsh T.

2007-01-01

The Savannah River Site (SRS) and Hanford site are in the process of stabilizing millions of gallons of radioactive waste slurries remaining from production of nuclear materials for the Department of Energy (DOE). The Defense Waste Processing Facility (DWPF) at SRS is currently vitrifying the waste in borosilicate glass, while the facilities at the Hanford site are in the construction phase. Both processes utilize slurry-fed joule-heated melters to vitrify the waste slurries. The DWPF has experienced difficulty during operations. The cause of the operational problems has been attributed to foaming, gas entrainment and the rheological properties of the process slurries. The rheological properties of the waste slurries limit the total solids content that can be processed by the remote equipment during the pretreatment and meter feed processes. Highly viscous material can lead to air entrainment during agitation and difficulties with pump operations. Excessive foaming in waste evaporators can cause carryover of radionuclides and non-radioactive waste to the condensate system. Experimental and theoretical investigations of the surface phenomena, suspension rheology and bubble generation of interactions that lead to foaming and air entrainment problems in the DOE High Level and Low Activity Radioactive Waste separation and immobilization processes were pursued under this project. The first major task accomplished in the grant proposal involved development of a theoretical model of the phenomenon of foaming in a three-phase gas-liquid-solid slurry system. This work was presented in a recently completed Ph.D. thesis (9). The second major task involved the investigation of the inter-particle interaction and microstructure formation in a model slurry by the batch sedimentation method. Both experiments and modeling studies were carried out. The results were presented in a recently completed Ph.D. thesis. The third task involved the use of laser confocal microscopy to study

Prototype demonstration of dual sorbent injection for acid gas control on municipal solid waste combustion units

Energy Technology Data Exchange (ETDEWEB)

None

1994-05-01

This report gathered and evaluated emissions and operations data associated with furnace injection of dry hydrated lime and duct injection of dry sodium bicarbonate at a commercial, 1500 ton per day, waste-to-energy facility. The information compiled during the project sheds light on these sorbents to affect acid gas emissions from municipal solid waste combustors. The information assesses the capability of these systems to meet the 1990 Clean Air Act and 1991 EPA Emission Guidelines.

Strategies to Reduce Greenhouse Gas Emissions from Laparoscopic Surgery.

Science.gov (United States)

Thiel, Cassandra L; Woods, Noe C; Bilec, Melissa M

2018-04-01

To determine the carbon footprint of various sustainability interventions used for laparoscopic hysterectomy. We designed interventions for laparoscopic hysterectomy from approaches that sustainable health care organizations advocate. We used a hybrid environmental life cycle assessment framework to estimate greenhouse gas emissions from the proposed interventions. We conducted the study from September 2015 to December 2016 at the University of Pittsburgh (Pittsburgh, Pennsylvania). The largest carbon footprint savings came from selecting specific anesthetic gases and minimizing the materials used in surgery. Energy-related interventions resulted in a 10% reduction in carbon footprint per case but would result in larger savings for the whole facility. Commonly implemented approaches, such as recycling surgical waste, resulted in less than a 5% reduction in greenhouse gases. To reduce the environmental emissions of surgeries, health care providers need to implement a combination of approaches, including minimizing materials, moving away from certain heat-trapping anesthetic gases, maximizing instrument reuse or single-use device reprocessing, and reducing off-hour energy use in the operating room. These strategies can reduce the carbon footprint of an average laparoscopic hysterectomy by up to 80%. Recycling alone does very little to reduce environmental footprint. Public Health Implications. Health care services are a major source of environmental emissions and reducing their carbon footprint would improve environmental and human health. Facilities seeking to reduce environmental footprint should take a comprehensive systems approach to find safe and effective interventions and should identify and address policy barriers to implementing more sustainable practices.

Microbial gas generation under expected Waste Isolation Pilot Plant repository conditions

International Nuclear Information System (INIS)

Francis, A.J.; Gillow, J.B.; Giles, M.R.

1997-03-01

Gas generation from the microbial degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository was investigated at Brookhaven National Laboratory. The biodegradation of mixed cellulosics (various types of paper) and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, neoprene, hypalon, and leaded hypalon) was examined. The rate of gas production from cellulose biodegradation in inundated samples incubated for 1,228 days at 30 C was biphasic, with an initial rapid rate up to approximately 600 days incubation, followed by a slower rate. The rate of total gas production in anaerobic samples containing mixed inoculum was as follows: 0.002 mL/g cellulose/day without nutrients; 0.004 mL/g cellulose/day with nutrients; and 0.01 mL/g cellulose/day in the presence of excess nitrate. Carbon dioxide production proceeded at a rate of 0.009 micromol/g cellulose/day in anaerobic samples without nutrients, 0.05 micromol/g cellulose/day in the presence of nutrients, and 0.2 micromol/g cellulose/day with excess nitrate. Adding nutrients and excess nitrate stimulated denitrification, as evidenced by the accumulation of N 2 O in the headspace (200 micromol/g cellulose). The addition of the potential backfill bentonite increased the rate of CO 2 production to 0.3 micromol/g cellulose/day in anaerobic samples with excess nitrate. Analysis of the solution showed that lactic, acetic, propionic, butyric, and valeric acids were produced due to cellulose degradation. Samples incubated under anaerobic humid conditions for 415 days produced CO 2 at a rate of 0.2 micromol/g cellulose/day in the absence of nutrients, and 1 micromol/g cellulose/day in the presence of bentonite and nutrients. There was no evidence of biodegradation of electron-beam irradiated plastic and rubber

Trash to Gas: Converting Space Waste into Useful Supply Products

Science.gov (United States)

Tsoras, Alexandra

2013-01-01

The cost of sending mass into space with current propulsion technology is very expensive, making every item a crucial element of the space mission. It is essential that all materials be used to their fullest potential. Items like food, packaging, clothing, paper towels, gloves, etc., normally become trash and take up space after use. These waste materials are currently either burned up upon reentry in earth's atmosphere or sent on cargo return vehicles back to earth: a very wasteful method. The purpose of this project was to utilize these materials and create useful products like water and methane gas, which is used for rocket fuel, to further supply a deep space mission. The system used was a thermal degradation reactor with the configuration of a down-draft gasifier. The reactor was loaded with approximately 100g of trash simulant and heated with two external ceramic heaters with separate temperature control in order to create pyrolysis and gasification in one zone and incineration iri a second zone simultaneously. Trash was loaded into the top half of the reactor to undergo pyrolysis while the downdraft gas experienced gasification or incineration to treat tars and maximize the production of carbon dioxide. Minor products included carbon monoxide, methane, and other hydrocarbons. The carbon dioxide produced can be sent to a Sabatier reactor to convert the gas into methane, which can be used as rocket propellant. In order to maximize the carbon dioxide and useful gases produced, and minimize the unwanted tars and leftover ashen material, multiple experiments were performed with altered parameters such as differing temperatures, flow rates, and location of inlet air flow. According to the data received from these experiments, the process will be further scaled up and optimized to ultimately create a system that reduces trash buildup while at the same time providing enough useful gases to potentially fill a methane tank that could fuel a lunar ascent vehicle or

Shipment and Disposal of Solidified Organic Waste (Waste Type IV) to the Waste Isolation Pilot Plant (WIPP)

International Nuclear Information System (INIS)

D'Amico, E. L; Edmiston, D. R.; O'Leary, G. A.; Rivera, M. A.; Steward, D. M.

2006-01-01

In April of 2005, the last shipment of transuranic (TRU) waste from the Rocky Flats Environmental Technology Site to the WIPP was completed. With the completion of this shipment, all transuranic waste generated and stored at Rocky Flats was successfully removed from the site and shipped to and disposed of at the WIPP. Some of the last waste to be shipped and disposed of at the WIPP was waste consisting of solidified organic liquids that is identified as Waste Type IV in the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC) document. Waste Type IV waste typically has a composition, and associated characteristics, that make it significantly more difficult to ship and dispose of than other Waste Types, especially with respect to gas generation. This paper provides an overview of the experience gained at Rocky Flats for management, transportation and disposal of Type IV waste at WIPP, particularly with respect to gas generation testing. (authors)

Greenhouse gas emissions from municipal solid waste management in Vientiane, Lao PDR.

Science.gov (United States)

Babel, Sandhya; Vilaysouk, Xaysackda

2016-01-01

Municipal solid waste (MSW) is one of the major environmental problems throughout the world including in Lao PDR. In Vientiane, due to the lack of a collection service, open burning and illegal dumping are commonly practised. This study aims to estimate the greenhouse gas (GHG) emission from the current situation of MSW management (MSWM) in Vientiane and proposes an alternative solution to reduce the GHG emission and environmental impacts. The 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories (IPCC 2006 model) are used for the estimation of GHG emission from landfill and composting. For the estimation of GHG emission from open burning, the Atmospheric Brown Clouds Emission Inventory Manual (ABC EIM) is used. In Vientiane, a total of 232, 505 tonnes year(-1) of MSW was generated in 2011. Waste generation in Vientiane is 0.69 kg per capita per day, and about 31% of the total MSW generated was directly sent to landfill (71,162 tonnes year(-1)). The total potential GHG emission from the baseline scenario in 2011 was 110,182 tonnes year(-1) CO2-eq, which is 0.15 tonne year(-1) CO2-eq per capita. From the three MSWM scenarios proposed, scenario S3, which includes recycling, composting and landfilling, seems to be an effective solution for dealing with MSW in Vientiane with less air pollution, and is environmentally friendly. The total GHG emission in scenario S3 is reduced to 91,920 tonnes year(-1) CO2-eq (47% reduction), compared with the S1 scenario where all uncollected waste is diverted to landfill. © The Author(s) 2015.

Generation of electricity and combustible gas by utilization of agricultural waste in Nara canal area water board

International Nuclear Information System (INIS)

Joyo, P.; Memon, F.; Sohag, M.A.

2005-01-01

Biomass in an important source of energy, however, it is not fully utilized in Sindh. The various types of biomass normally used for the generation of energy are extensively available in the province. These are forest debris and thinning; residue from wood products industry; agricultural waste; fast-growing trees and crops; wood and wood waste; animal manures and non-hazardous organic portion of municipal solid waste. Since agriculture is pre-dominant in Sindh, it has a large amount of agricultural waste available in most of the areas. Agriculture wastes like rice husk, wheat straw, cotton stalks, and sugarcane bagasse can be utilized to produce gas and afterwards electricity. Pakistan Agricultural Research Council (PARC) has found that at most of the locations of Sindh, agricultural waste is available more than the energy requirements of that particular area. Biomass can also generate electricity (or heat) in one of the several processes, can be used in a piston driven engine, high efficiency gas turbine generator or a fuel cell to produce electricity. Biomass gasifies have gained attention for their efficiency, economy and environment-friendly. The Nara Canal Area Water Board is facing acute problem of electricity in the O and M of its drainage network and running of tube wells. The frequent breakdown and irregular supply of power is badly affecting in the management of drainage system and control of rising water-table, however, it is anticipated that the generation of electricity through biomass can address this acute problem and greatly help in controlling water logging and salinity in Sindh. (author)

Greenhouse gas emission mitigation relevant to changes in municipal solid waste management system.

Science.gov (United States)

Pikoń, Krzysztof; Gaska, Krzysztof

2010-07-01

Standard methods for assessing the environmental impact of waste management systems are needed to underpin the development and implementation of sustainable waste management practice. Life cycle assessment (LCA) is a tool for comprehensively ensuring such assessment and covers all impacts associated with waste management. LCA is often called "from cradle to grave" analysis. This paper integrates information on the greenhouse gas (GHG) implications of various management options for some of the most common materials in municipal solid waste (MSW). Different waste treatment options for MSW were studied in a system analysis. Different combinations of recycling (cardboard, plastics, glass, metals), biological treatment (composting), and incineration as well as land-filling were studied. The index of environmental burden in the global warming impact category was calculated. The calculations are based on LCA methodology. All emissions taking place in the whole life cycle system were taken into account. The analysis included "own emissions," or emissions from the system at all stages of the life cycle, and "linked emissions," or emissions from other sources linked with the system in an indirect way. Avoided emissions caused by recycling and energy recovery were included in the analysis. Displaced emissions of GHGs originate from the substitution of energy or materials derived from waste for alternative sources. The complex analysis of the environmental impact of municipal waste management systems before and after application of changes in MSW systems according to European Union regulations is presented in this paper. The evaluation is made for MSW systems in Poland.

Topical anesthetic versus lidocaine infiltration in arteriovenous fistula cannulation

Directory of Open Access Journals (Sweden)

Anisha George

2014-01-01

Full Text Available Background: End stage renal disease (ESRD patients on maintenance hemodialysis undergo arterio-venous fistula (AVF cannulation prior to each hemodialysis session for blood access. Prior to cannulation lidocaine infiltration is done, which is often perceived as painful. Eutectic mixture of local anesthetic (EMLA has been found to significantly reduce pain associated with radial artery cannulation compared with lidocaine infiltration. Aims: To evaluate the efficacy of EMLA compared to infiltration of lidocaine in hemodialysis patients for AVF cannulation. Materials and Methods: A single-centre, crossover study of patients with an AVF on regular maintenance hemodialysis was performed in the dialysis unit of a tertiary care teaching hospital. The site of AVF, number of attempts for AVF cannulation and cannula insertion time were recorded. The patients were asked about the acceptability of application of the anesthetic, delay between anesthetic and cannulation and to score the pain on cannulation. Results: Fifty patients were included in the study. With the visual analog scale, pain score on infiltration was 4.8. Pain score on cannulation after topical application was 2.9 and after infiltration, 2.0. The number of attempts for cannulation and the cannula insertion time were similar. Anesthesia was more stressful in the injectable group rather than the topical group (P < 0.001. Delay between anesthetic and cannulation was unacceptable in the topical group (P < 0.001. Patient compliance was better during infiltration compared to topical (P < 0.005. Mean pain score during infiltration of anesthetic was significantly higher than cannulation pain after either anesthetic, although pain on cannulation was higher in the topical group (P < 0.001. Conclusions: EMLA offers a suitable alternative to lidocaine infiltration for patients using AVF for blood access.

Paired assessment of volatile anesthetic concentrations with synaptic actions recorded in vitro.

Directory of Open Access Journals (Sweden)

Stuart J McDougall

Full Text Available The volatile anesthetic isoflurane poses a number of experimental challenges in the laboratory. Due to its rapid evaporation, the open conditions of most in vitro electrophysiological recording systems make the determination of actual isoflurane concentrations a challenge. Since the absolute anesthetic concentration in solution is directly related to efficacy, concentration measurements are important to allow comparisons between laboratory and clinical studies. In this study we quantify the sources of isoflurane loss during experimentation and describe a method for the measurement of isoflurane concentrations using gas chromatography and mass spectrometry simultaneous to in vitro electrophysiological measurements. Serial samples of perfused bath solution allowed correlation of isoflurane concentrations with ongoing biological effects. Saturated physiological solutions contained 13.4 +/- 0.2 mM isoflurane and were diluted to desired "nominal" concentrations for experiments. The perfusion system established stable isoflurane concentrations within the bath by 2 minutes. However, bath isoflurane concentrations varied substantially and unpredictably between experiments. The magnitudes of such discrepancies in isoflurane concentrations spanned clinically important levels. Our studies suggest that, despite countermeasures, solution handling significantly impacted the isoflurane content in the tissue bath. The magnitude of these discrepancies appears to necessitate systematic direct measurement of bath isoflurane concentrations during most in vitro conditions.

Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke.

Science.gov (United States)

Wang, Hailian; Li, Peiying; Xu, Na; Zhu, Ling; Cai, Mengfei; Yu, Weifeng; Gao, Yanqin

2016-01-01

Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

LABORATORY OPTIMIZATION TESTS OF TECHNETIUM DECONTAMINATION OF HANFORD WASTE TREATMENT PLANT LOW ACTIVITY WASTE OFF-GAS CONDENSATE SIMULANT

Energy Technology Data Exchange (ETDEWEB)

Taylor-Pashow, K.; Nash, C.; McCabe, D.

2014-09-29

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility again. Alternate disposition of this stream would eliminate recycling of problematic components, and would enable de-coupled operation of the LAW melter and the Pretreatment Facilities. Eliminating this stream from recycling within WTP would also decrease the LAW vitrification mission duration and quantity of glass waste. This LAW Off-Gas Condensate stream contains components that are volatile at melter temperatures and are problematic for the glass waste form. Because this stream recycles within WTP, these components accumulate in the Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Approximately 32% of the sodium in Supplemental LAW comes from glass formers used to make the extra glass to dilute the halides to acceptable concentrations in the LAW glass, and diverting the stream reduces the halides in the recycled Condensate and is a key outcome of this work. Additionally, under possible scenarios where the LAW vitrification facility commences operation prior to the WTP Pretreatment facility, identifying a disposition path becomes vitally important. This task examines the potential treatment of this stream to remove radionuclides and subsequently disposition the decontaminated stream elsewhere, such as the Effluent Treatment Facility (ETF), for example. The treatment process envisioned is very similar to that used for the Actinide Removal Process (ARP) that has been operating for years at the Savannah River Site (SRS), and focuses on using mature radionuclide removal technologies that are also

Radioactivity in wastes generated from shale gas exploration and production - North-Eastern Poland.

Science.gov (United States)

Jodłowski, Paweł; Macuda, Jan; Nowak, Jakub; Nguyen Dinh, Chau

2017-09-01

In the present study, the K-40, U-238, Ra-226, Pb-210, Ra-228 and Th-228 activity concentrations were measured in 64 samples of wastes generated from shale gas exploration in North-Eastern Poland. The measured samples consist of drill cuttings, solid phase of waste drilling muds, fracking fluids, return fracking fluids and waste proppants. The measured activity concentrations in solid samples vary in a wide range from 116 to around 1100 Bq/kg for K-40, from 14 to 393 Bq/kg for U-238, from 15 to 415 Bq/kg for Ra-226, from 12 to 391 Bq/kg for Pb-210, from a few Bq/kg to 516 Bq/kg for Ra-228 and from a few Bq/kg to 515 Bq/kg for Th-228. Excluding the waste proppants, the measured activity concentrations in solid samples oscillate around their worldwide average values in soil. In the case of the waste proppants, the activity concentrations of radionuclides from uranium and thorium decay series are significantly elevated and equal to several hundreds of Bq/kg but it is connected with the mineralogical composition of proppants. The significant enhancement of Ra-226 and Ra-228 activity concentrations after fracking process was observed in the case of return fracking fluids, but the radium isotopes content in these fluids is comparable with that in waste waters from copper and coal mines in Poland. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mechanisms of gas generation from simulated SY tank farm wastes: FY 1995 progress report

International Nuclear Information System (INIS)

Barefield, E.K.; Boatright, D.; Deshpande, A.; Doctorovich, F.; Liotta, C.L.; Neumann, H.M.; Seymore, S.

1996-07-01

The objective of this work is to develop a better understanding of the mechanism of formation of flammable gases in the thermal decomposition of metal complexants such as HEDTA and sodium glycolate in simulated SY tank farm waste mixtures. This report summarizes the results of work done at the Georgia Institute of Technology in fiscal year 1995. Topics discussed are (1) long-term studies of the decomposition of HEDTA in simulated waste mixtures under an argon atmosphere at 90 and 120 degrees C, including time profiles for disappearance of HEDTA and appearance of products and the quantitative analysis of the kinetic behavior; (2) considerations of hydroxylamine as an intermediate in the production of nitrogen containing gases by HEDTA decomposition; (3) some thoughts on the revision of the global mechanism for thermal decomposition of HEDTA under argon; (4) preliminary long-term studies of the decomposition of HEDTA in simulated waste under an oxygen atmosphere at 120 degrees C; (5) estimation of the amount of NH 3 in the gas phase above HEDTA reaction mixtures; and (6) further, examination of the interaction of aluminum with nitrite ion using 27 Al NMR spectroscopy. Section 2 of this report describes the work conducted over the last three years at GIT. Section 3 contains a discussion of the kinetic behavior of HEDTA under argon; Section 4 discusses the role of hydroxylamine. Thermal decomposition of HEDTA to ED3A is the subject of Section 5, and decomposition of HEDTA in simulated waste mixtures under oxygen is covered in Section 6. In Section 7 we estimate ammonia in the gas phase; the role of aluminum is discussed in Section 8

Improved Hydrogen Gas Getters for TRU Waste Transuranic and Mixed Waste Focus Area - Phase 2 Final Report

Energy Technology Data Exchange (ETDEWEB)

Stone, Mark Lee

2002-04-01

Alpha radiolysis of hydrogenous waste and packaging materials generates hydrogen gas in radioactive storage containers. For that reason, the Nuclear Regulatory Commission (NRC) limits the flammable gas (hydrogen) concentration in the Transuranic Package Transporter-II (TRUPACT-II) containers to 5 vol% of hydrogen in air, which is the lower explosion limit. Consequently, a method is needed to prevent the build up of hydrogen to 5 vol% during the storage and transport of the TRUPACT-II containers (up to 60 days). One promising option is the use of hydrogen getters. These materials scavenge hydrogen from the gas phase and irreversibly bind it in the solid phase. One proven getter is a material called 1,4-bis (phenylethynyl) benzene, or DEB. It has the needed binding rate and capacity, but some of the chemical species that might be present in the containers could interfere with its ability to remove hydrogen. This project is focused upon developing a protective polymeric membrane coating for the DEB getter material, which comes in the form of small, irregularly shaped particles. This report summarizes the experimental results of the second phase of the development of the materials.

The role of quantitative uncertainty in the safety analysis of flammable gas accidents in Hanford waste tanks

International Nuclear Information System (INIS)

Bratzel, D.R.

1998-01-01

Following a 1990 investigation into flammable gas generation, retention, and release mechanisms within the Hanford Site high-level waste tanks, personnel concluded that the existing Authorization Basis documentation did not adequately evaluate flammable gas hazards. The US Department of Energy Headquarters subsequently declared the flammable gas hazard as an unresolved safety issue. Although work scope has been focused on resolution of the issue, it has yet to be resolved due to considerable uncertainty regarding essential technical parameters and associated risk. Resolution of the Flammable Gas Safety Issue will include the identification of a set of controls for the Authorization Basis for the tanks which will require a safety analysis of flammable gas accidents. A traditional nuclear facility safety analysis is based primarily on the analysis of a set of bounding accidents to represent the risks of the possible accidents and hazardous conditions at a facility. While this approach may provide some indication of the bounding consequences of accidents for facilities, it does not provide a satisfactory basis for identification of facility risk or safety controls when there is considerable uncertainty associated with accident phenomena and/or data as is the case with potential flammable gas accidents at the Hanford Site. This is due to the difficulties in identifying the bounding case and reaching consensus among safety analysts, facility operations and engineering, and the regulator on the implications of the safety analysis results. In addition, the bounding cases are frequently based on simplifying assumptions that make the analysis results insensitive to variations among facilities or the impact of alternative safety control strategies. The existing safety analysis of flammable gas accidents for the Tank Waste Remediation system (TWRS) at the Hanford Site has these difficulties. However, Hanford Site personnel are developing a refined safety analysis approach

Multivariable analysis of anesthetic factors associated with time to extubation in dogs.

Science.gov (United States)

Kleine, Stephanie; Hofmeister, Erik; Egan, Katrina

2014-12-01

The purpose of this study was to identify factors that prolong the time to extubation in dogs. Anesthetic records of 900 dogs at a university teaching hospital were searched. Multiple linear regression was used to compare independent predictors (patient demographics, anesthetic and intraoperative variables) with the dependent variable (time to extubation). Induction with propofol (P temperature (P = 0.0000), and by 0.096 minutes for every 1 minute increase in anesthetic duration (P = 0.000). Anesthetic variables, which can be manipulated by the anesthetist, include choice of premedication and induction drugs, hypothermia, and duration of anesthesia. Published by Elsevier Ltd.

Fundamentals of gas flow in shale; What the unconventional reservoir industry can learn from the radioactive waste industry

Science.gov (United States)

Cuss, Robert; Harrington, Jon; Graham, Caroline

2013-04-01

Tight formations, such as shale, have a wide range of potential usage; this includes shale gas exploitation, hydrocarbon sealing, carbon capture & storage and radioactive waste disposal. Considerable research effort has been conducted over the last 20 years on the fundamental controls on gas flow in a range of clay-rich materials at the British Geological Survey (BGS) mainly focused on radioactive waste disposal; including French Callovo-Oxfordian claystone, Belgian Boom Clay, Swiss Opalinus Clay, British Oxford Clay, as well as engineered barrier material such as bentonite and concrete. Recent work has concentrated on the underlying physics governing fluid flow, with evidence of dilatancy controlled advective flow demonstrated in Callovo-Oxfordian claystone. This has resulted in a review of how advective gas flow is dealt with in Performance Assessment and the applicability of numerical codes. Dilatancy flow has been shown in Boom clay using nano-particles and is seen in bentonite by the strong hydro-mechanical coupling displayed at the onset of gas flow. As well as observations made at BGS, dilatancy flow has been shown by other workers on shale (Cuss et al., 2012; Angeli et al. 2009). As well as experimental studies using cores of intact material, fractured material has been investigated in bespoke shear apparatus. Experimental results have shown that the transmission of gas by fractures is highly localised, dependent on normal stress, varies with shear, is strongly linked with stress history, is highly temporal in nature, and shows a clear correlation with fracture angle. Several orders of magnitude variation in fracture transmissivity is seen during individual tests. Flow experiments have been conducted using gas and water, showing remarkably different behaviour. The radioactive waste industry has also noted a number of important features related to sample preservation. Differences in gas entry pressure have been shown across many laboratories and these may be

Greenhouse gas footprint and the carbon flow associated with different solid waste management strategy for urban metabolism in Bangladesh.

Science.gov (United States)

Islam, K M Nazmul

2017-02-15

Greenhouse gas (GHG) emissions from municipal solid waste (MSW) and associated climate change consequences are gripping attention globally, while MSW management as a vital subsystem of urban metabolism significantly influences the urban carbon cycles. This study evaluates the GHG emissions and carbon flow of existing and proposed MSW management in Bangladesh through scenario analysis, including landfill with landfill gas (LFG) recovery, waste to energy (WtE), and material recovery facility (MRF). The analysis indicates that, scenario H 2 and H 5 emitted net GHGs -152.20kg CO 2 eq. and -140.32kg CO 2 eq., respectively, in comparison with 420.88kg CO 2 eq. of scenario H 1 for managing per ton of wastes during the reference year 2015. The annual horizontal carbon flux of the waste input was 319Gg and 158Gg during 2015 in Dhaka and Chittagong, respectively. An integrated strategy of managing the wastes in the urban areas of Bangladesh involving WtE incineration plant and LFG recovery to generate electricity as well as MRF could reverse back 209.46Gg carbon and 422.29Gg carbon to the Chittagong and Dhaka urban system, respectively. This study provides valuable insights for the MSW policy framework and revamp of existing MSW management practices with regards to reduction of GHGs emissions from the waste sector in Bangladesh. Copyright © 2016 Elsevier B.V. All rights reserved.

Screening the Hanford tanks for trapped gas

International Nuclear Information System (INIS)

Whitney, P.

1995-10-01

The Hanford Site is home to 177 large, underground nuclear waste storage tanks. Hydrogen gas is generated within the waste in these tanks. This document presents the results of a screening of Hanford's nuclear waste storage tanks for the presence of gas trapped in the waste. The method used for the screening is to look for an inverse correlation between waste level measurements and ambient atmospheric pressure. If the waste level in a tank decreases with an increase in ambient atmospheric pressure, then the compressibility may be attributed to gas trapped within the waste. In this report, this methodology is not used to estimate the volume of gas trapped in the waste. The waste level measurements used in this study were made primarily to monitor the tanks for leaks and intrusions. Four measurement devices are widely used in these tanks. Three of these measure the level of the waste surface. The remaining device measures from within a well embedded in the waste, thereby monitoring the liquid level even if the liquid level is below a dry waste crust. In the past, a steady rise in waste level has been taken as an indicator of trapped gas. This indicator is not part of the screening calculation described in this report; however, a possible explanation for the rise is given by the mathematical relation between atmospheric pressure and waste level used to support the screening calculation. The screening was applied to data from each measurement device in each tank. If any of these data for a single tank indicated trapped gas, that tank was flagged by this screening process. A total of 58 of the 177 Hanford tanks were flagged as containing trapped gas, including 21 of the 25 tanks currently on the flammable gas watch list

Monitoring gas retention and slurry transport during the transfer of waste from Tank 241-C-106 to Tank 241-AY-102

International Nuclear Information System (INIS)

Stewart, C.W.; Erian, F.F.; Meyer, P.A.

1997-07-01

The retained gas volume can be estimated by several methods. All of these methods have significant uncertainties, but together they form a preponderance of evidence that describes the gas retention behavior of the tank. The methods are (1) an increase in nonconvective layer thickness; (2) a waste surface level rise (surface level effect [SLE] model); (3) the barometric pressure effect (BPE model); (4) direct void measurement; and (5) the consequences of the transfer process. The nonconvective layer thickness can be determined with sufficient accuracy to describe the overall waste configuration by means of temperature profiles or densitometer indications. However, the presence of a nonconvective layer does not necessarily indicate significant gas retention, and small changes in layer thickness that could quantify gas retention cannot be detected reliably with the methods available. The primary value of this measurement is in establishing the actual open-quotes fluffing factorclose quotes for thermal calculations. Surface level rise is not a useful measure of gas retention in Tank 241-C-106 (C-106) since the waste level fluctuates with regular makeup water additions. In Tank 241-AY-102 (AY-102) with the existing ventilation system it should be possible to determine the gas retention rate within 30-60% uncertainty from the surface level rise, should a significant rise be observed. The planned ventilation system upgrades in AY- 102 will greatly reduce the exhaust flow and the headspace humidity, and the evaporation rate should be significantly lower when transfers begin. This could reduce the uncertainty in gas retention rate estimates to around ± 10%

Norm waste management in Malaysia

International Nuclear Information System (INIS)

Muhamat Omar

2000-01-01

There are a number of industries generating NORM wastes in Malaysia. These include oil and gas and minerals/ores processing industries. A safe management of radioactive wastes is required. The existing guidelines are insufficient to help the management of oil and gas wastes. More guidelines are required to deal with NORM wastes from minerals/ores processing industries. To ensure that radioactive wastes are safely managed and disposed of, a National Policy on the Safe Management of Radioactive Waste is being developed which also include NORM waste. This paper describes the current status of NORM waste management in Malaysia. (author)

Anesthetic Approach to a Child with Noonan's Syndrome

Directory of Open Access Journals (Sweden)

Zehra Hatipoglu

2015-03-01

Full Text Available Noonan syndrome is characterized by fascial and physical features along with congenital heart disease. In these patients, fascial features include short webbed neck, micrognathia, limited mouth opening and high arched palate. Pulmonary stenosis and hypertrophic obstructive cardiomyopathy are highly prevalent in Noonan's syndrome. The anesthetic management is important because of difficult airway and severe cardiac abnormalities. We reported that anesthetic management of a child with Noonan's syndrome. [Cukurova Med J 2015; 40(Suppl 1: 47-50

Possibilities of mercury removal in the dry flue gas cleaning lines of solid waste incineration units.

Science.gov (United States)

Svoboda, Karel; Hartman, Miloslav; Šyc, Michal; Pohořelý, Michael; Kameníková, Petra; Jeremiáš, Michal; Durda, Tomáš

2016-01-15

Dry methods of the flue gas cleaning (for HCl and SO2 removal) are useful particularly in smaller solid waste incineration units. The amount and forms of mercury emissions depend on waste (fuel) composition, content of mercury and chlorine and on the entire process of the flue gas cleaning. In the case of high HCl/total Hg molar ratio in the flue gas, the majority (usually 70-90%) of mercury is present in the form of HgCl2 and a smaller amount in the form of mercury vapors at higher temperatures. Removal of both main forms of mercury from the flue gas is dependent on chemical reactions and sorption processes at the temperatures below approx. 340 °C. Significant part of HgCl2 and a small part of elemental Hg vapors can be adsorbed on fly ash and solid particle in the air pollution control (APC) processes, which are removed in dust filters. Injection of non-impregnated active carbon (AC) or activated lignite coke particles is able to remove mainly the oxidized Hg(2+) compounds. Vapors of metallic Hg(o) are adsorbed relatively weakly. Much better chemisorption of Hg(o) together with higher sorbent capacity is achieved by AC-based sorbents impregnated with sulfur, alkali poly-sulfides, ferric chloride, etc. Inorganic sorbents with the same or similar chemical impregnation are also applicable for deeper Hg(o) removal (over 85%). SCR catalysts convert part of Hg(o) into oxidized compounds (HgO, HgCl2, etc.) contributing to more efficient Hg removal, but excess of NH3 has a negative effect. Both forms, elemental Hg(o) and HgCl2, can be converted into HgS particles by reacting with droplets/aerosol of poly-sulfides solutions/solids in flue gas. Mercury captured in the form of water insoluble HgS is more advantageous in the disposal of solid waste from APC processes. Four selected options of the dry flue gas cleaning with mercury removal are analyzed, assessed and compared (in terms of efficiency of Hg-emission reduction and costs) with wet methods and retrofits for more

Paradigms and mechanisms of inhalational anesthetics mediated neuroprotection against cerebral ischemic stroke

Directory of Open Access Journals (Sweden)

Hailian Wang

2016-01-01

Full Text Available Cerebral ischemic stroke is a leading cause of serious long-term disability and cognitive dysfunction. The high mortality and disability of cerebral ischemic stroke is urging the health providers, including anesthesiologists and other perioperative professioners, to seek effective protective strategies, which are extremely limited, especially for those perioperative patients. Intriguingly, several commonly used inhalational anesthetics are recently suggested to possess neuroprotective effects against cerebral ischemia. This review introduces multiple paradigms of inhalational anesthetic treatments that have been investigated in the setting of cerebral ischemia, such as preconditioning, proconditioning and postconditioning with a variety of inhalational anesthetics. The pleiotropic mechanisms underlying these inhalational anesthetics-afforded neuroprotection against stroke are also discussed in detail, including the common pathways shared by most of the inhalational anesthetic paradigms, such as anti-excitotoxicity, anti-apoptosis and anti-inflammation. There are also distinct mechanisms involved in specific paradigms, such as preserving blood brain barrier integrity, regulating cerebral blood flow and catecholamine release. The ready availability of these inhalational anesthetics bedside and renders them a potentially translatable stroke therapy attracting great efforts for understanding of the underlying mechanisms.

[Removal of toluene from waste gas by honeycomb adsorption rotor with modified 13X molecular sieves].

Science.gov (United States)

Wang, Jia-De; Zheng, Liang-Wei; Zhu, Run-Ye; Yu, Yun-Feng

2013-12-01

The removal of toluene from waste gas by Honeycomb Adsorption Rotor with modified 13X molecular sieves was systematically investigated. The effects of the rotor operating parameters and the feed gas parameters on the adsorption efficiency were clarified. The experimental results indicated that the honeycomb adsorption rotor had a good humidity resistance. The removal efficiency of honeycomb adsorption rotor achieved the maximal value with optimal rotor speed and optimal generation air temperature. Moreover, for an appropriate flow rate ratio the removal efficiency and energy consumption should be taken into account. When the recommended operating parameters were regeneration air temperature of 180 degrees C, rotor speed of 2.8-5 r x h(-1), flow rate ratio of 8-12, the removal efficiency kept over 90% for the toluene gas with concentration of 100 mg x m(-3) and inlet velocity of 2 m x s(-1). The research provided design experience and operating parameters for industrial application of honeycomb adsorption rotor. It showed that lower empty bed velocity, faster rotor speed and higher temperature were necessary to purify organic waste gases of higher concentrations.

Ways to achieve optimum utilization of waste gas heat in cement kiln plants with cyclone preheaters

Energy Technology Data Exchange (ETDEWEB)

Steinbiss, E

1986-02-01

Kiln exit gases and the exhaust gases from clinker coolers often cannot be fully utilized in drying plants. In such cases a part of the heat content of the gases should be utilized for water heating. In addition, it is possible to utilize the waste gas heat in conventional steam boilers, with which, depending on design, it is possible to generate electricity at a rate of between 10-30 kWh/t (net output). A new and promising method of utilization of waste gas heat is provided by precalcining systems with bypass, in which up to 100% of the kiln exit gases can be economically bypassed and be utilized in a steam boiler, without requiring any cooling. A development project, already started, gives information on the operational behaviour of such a plant and on the maximum energy recoverable. Alternatively, the bypass gases may, after partial cooling with air or preheater exit gas, be dedusted and then utilized in a grinding/drying plant. Furthermore, they can be used in the cement grinding process for the drying of wet granulated blastfurnace slag or other materials. For this it is not necessary to dedust the bypass gases.

METHODOLOGY & CALCULATIONS FOR THE ASSIGNMENT OF WASTE FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

Energy Technology Data Exchange (ETDEWEB)

TU, T.A.

2007-01-04

Waste stored within tank farm double-shell tanks (DST) and single-shell tanks (SST) generates flammable gas (principally hydrogen) to varying degrees depending on the type, amount, geometry, and condition of the waste. The waste generates hydrogen through the radiolysis of water and organic compounds, thermolytic decomposition of organic compounds, and corrosion of a tank's carbon steel walls. Radiolysis and thermolytic decomposition also generates ammonia. Nonflammable gases, which act as dilutents (such as nitrous oxide), are also produced. Additional flammable gases (e.g., methane) are generated by chemical reactions between various degradation products of organic chemicals present in the tanks. Volatile and semi-volatile organic chemicals in tanks also produce organic vapors. The generated gases in tank waste are either released continuously to the tank headspace or are retained in the waste matrix. Retained gas may be released in a spontaneous or induced gas release event (GRE) that can significantly increase the flammable gas concentration in the tank headspace as described in RPP-7771, Flammable Gas Safety Isme Resolution. Appendices A through I provide supporting information. The document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste and characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 6 is the annual update of the flammable gas Waste Groups for DSTs and SSTs.

Apneic oxygenation combined with extracorporeal arteriovenous carbon dioxide removal provides sufficient gas exchange in experimental lung injury

DEFF Research Database (Denmark)

Nielsen, Niels Dalsgaard; Kjærgaard, Benedict; Koefoed-Nielsen, Jacob

2008-01-01

We hypothesized that apneic oxygenation, using an open lung approach, combined with extracorporeal CO2 removal, would provide adequate gas exchange in acute lung injury. We tested this hypothesis in nine anesthetized and mechanically ventilated pigs (85-95 kg), in which surfactant was depleted fr....../min. Thus, the method provided adequate gas exchange in this experimental model, suggesting that it might have potential as an alternative treatment modality in acute lung injury.......We hypothesized that apneic oxygenation, using an open lung approach, combined with extracorporeal CO2 removal, would provide adequate gas exchange in acute lung injury. We tested this hypothesis in nine anesthetized and mechanically ventilated pigs (85-95 kg), in which surfactant was depleted from...

21 CFR 868.5430 - Gas-scavenging apparatus.

Science.gov (United States)

2010-04-01

...) Identification. A gas-scavenging apparatus is a device intended to collect excess anesthetic, analgesic, or trace gases or vapors from a patient's breathing system, ventilator, or extracorporeal pump-oxygenator, and to conduct these gases out of the area by means of an exhaust system. (b) Classification. Class II...

Flammable gas tank safety program: Technical basis for gas analysis and monitoring

International Nuclear Information System (INIS)

Sherwood, D.J.

1995-01-01

Flammable gases generated in radioactive liquids. Twenty-five high level radioactive liquid waste storage tanks located underground at the Hanford Site are on a Flammable Gas Watch List because they contain waste which tends to retain the gases generated in it until rather large quantities are available for sudden release to the tank head space; if a tank is full it has little dome space, and a flammable concentration of gases could be produced--even if the tank is ventilated. If the waste has no tendency to retain gas generated in it then a continual flammable gas concentration in the tank dome space is established by the gas production rate and the tank ventilation rate (or breathing rate for unventilated tanks); this is also a potential problem for Flammable Gas Watch List tanks, and perhaps other Hanford tanks too. All Flammable Gas Watch List tanks will be fitted with Standard Hydorgen Monitoring Systems so that their behavior can be observed. In some cases, such as tank 241-SY-101, the data gathered from such observations will indicate that tank conditions need to be mitigated so that gas release events are either eliminated or rendered harmless. For example, a mixer pump was installed in tank 241-SY-101; operating the pump stirs the waste, replacing the large gas release events with small releases of gas that are kept below twenty-five percent of the lower flammability limit by the ventilation system. The concentration of hydrogen measured in Hanford waste tanks is greater than that of any other flammable gas. Hydrogen levels measured with a Standard Hydrogen Monitoring System in excess of 0.6 volume percent will cause Westinghouse Hanford Company to consider actions which will decrease the amount of flammable gas in the tank

Composition, preparation, and gas generation results from simulated wastes of Tank 241-SY-101

International Nuclear Information System (INIS)

Bryan, S.A.; Pederson, L.R.

1994-08-01

This document reviews the preparation and composition of simulants that have been developed to mimic the wastes temporarily stored in Tank 241-SY-101 at Hanford. The kinetics and stoichiometry of gases that are generated using these simulants are also compared, considering the roles of hydroxide, chloride, and transition metal ions; the identities of organic constituents; and the effects of dilution, radiation, and temperature. Work described in this report was conducted for the Flammable Gas Safety Program at Pacific Northwest Laboratory, (a) whose purpose is to develop information that is necessary to mitigate potential safety hazards associated with waste tanks at the Hanford Site. The goal of this research and of related efforts at the Georgia Institute of Technology (GIT), Argonne National Laboratory (ANL), and Westinghouse Hanford Company (WHC) is to determine the thermal and thermal/radiolytic mechanisms by which flammable and other gases are produced in Hanford wastes, emphasizing those stored in Tank 241-SY-101. A variety of Tank 241-SY-101 simulants have been developed to date. The use of simulants in laboratory testing activities provides a number of advantages, including elimination of radiological risks to researchers, lower costs associated with experimentation, and the ability to systematically alter simulant compositions to study the chemical mechanisms of reactions responsible for gas generation. The earliest simulants contained the principal inorganic components of the actual waste and generally a single complexant such as N-(2-hydroxyethyl) ethylenediaminetriacetic acid (HEDTA) or ethylenediaminetriacetic acid (EDTA). Both homogeneous and heterogeneous compositional forms were developed. Aggressive core sampling and analysis activities conducted during Windows C and E provided information that was used to design new simulants that more accurately reflected major and minor inorganic components

Possibilities of Mercury Removal in the Dry Flue Gas Cleaning Lines of Solid Waste Incineration Units

Czech Academy of Sciences Publication Activity Database

Svoboda, Karel; Hartman, Miloslav; Šyc, Michal; Pohořelý, Michael; Kameníková, Petra; Jeremiáš, Michal; Durda, Tomáš

2016-01-01

Roč. 166, JAN 15 (2016), s. 499-511 ISSN 0301-4797 R&D Projects: GA TA ČR TE02000236 Institutional support: RVO:67985858 Keywords : waste incineration * mercury removal * flue gas Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 4.010, year: 2016

Developments in, and environmental impacts of, electricity generation from municipal solid waste and landfill gas combustion

International Nuclear Information System (INIS)

Porteous, A.

1993-01-01

The 1991 NFFO allocations for renewable energy generation are reviewed with emphasis on electricity from municipal solid waste (MSW) and landfill gas (LFG) combustion tranches. The implications of materials recovery on the calorific value of MSW are considered, as are the environmental impacts of both MSW and LFG combustion with special reference to air pollutant emissions. The performance and economics of state of the art incineration and LFG power generating plants are examined. It is shown that energy recovery from these wastes can be both cost effective and environmentally desirable. (Author)

Anesthetizing the obese child

DEFF Research Database (Denmark)

Mortensen, Anette; Lenz, Katja; Abildstrøm, Hanne

2011-01-01

drugs. This has important implications on how to estimate the optimal drug dose. This article offers a review of the literature on definition, prevalence and the pathophysiology of childhood obesity and provides suggestions on preanesthetic evaluation, airway management and dosage of the anesthetic...... drugs in these patients. The authors highlight the need of supplemental studies on various areas of the subject....

Economic assessment of greenhouse gas reduction through low-grade waste heat recovery using organic Rankine cycle (ORC)

Energy Technology Data Exchange (ETDEWEB)

Imran, Muhammad; Park, Byung Sik; Kim, Hyouck Ju; Usman, Muhammad [University of Science and Technology, Daejeon (Korea, Republic of); Lee, Dong Hyun [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

2015-02-15

Low-grade waste heat recovery technologies reduce the environmental impact of fossil fuels and improve overall efficiency. This paper presents the economic assessment of greenhouse gas (GHG) reduction through waste heat recovery using organic Rankine cycle (ORC). The ORC engine is one of the mature low temperature heat engines. The low boiling temperature of organic working fluid enables ORC to recover low-temperature waste heat. The recovered waste heat is utilized to produce electricity and hot water. The GHG emissions for equivalent power and hot water from three fossil fuels-coal, natural gas, and diesel oil-are estimated using the fuel analysis approach and corresponding emission factors. The relative decrease in GHG emission is calculated using fossil fuels as the base case. The total cost of the ORC system is used to analyze the GHG reduction cost for each of the considered fossil fuels. A sensitivity analysis is also conducted to investigate the effect of the key parameter of the ORC system on the cost of GHG reduction. Throughout the 20-year life cycle of the ORC plant, the GHG reduction cost for R245fa is 0.02 $/kg to 0.04 $/kg and that for pentane is 0.04 $/kg to 0.05 $/kg. The working fluid, evaporation pressure, and pinch point temperature difference considerably affect the GHG emission.

Anesthetic activity of Brazilian native plants in silver catfish (Rhamdia quelen

Directory of Open Access Journals (Sweden)

Lenise de Lima Silva

Full Text Available There is an increasing demand for inexpensive and safe anesthetics that can reduce fish stress caused by some procedures such as capture and handling. In this context, the present study evaluated the potential of essential oils (EO of three Brazilian native plants (Hesperozygis ringens, Lippia sidoides and Ocotea acutifolia as anesthetics for the silver catfish - Rhamdia quelen. Moreover, an analysis was made of the chemical composition of these oils and their influence on stress parameter. EO of H. ringens and O. acutifolia were effective as anesthetics, without behavioral side effects. EO of O. acutifolia (150 µL L-1 promoted an increase in blood glucose level. Regarding to the composition, pulegone accounts for 96.63% of the EO of H. ringens, and caryophyllene oxide amounts to 56.90% of the EO of O. acutifolia. Two chemotypes, thymol and carvacrol (68.40% and 67.89%, respectively were verified for EO of L. sidoides. Both samples of EO of L. sidoides showed anesthetic activity in silver catfish, but exposure also caused loss of mucus and mortality. Thus, only the EO of H. ringens and O. acutifolia are advised for anesthetic use

Comparison of potential greenhouse gas emissions from disposal of MSW in sanitary landfills vs. waste-to-energy facilities

International Nuclear Information System (INIS)

Taylor, H.F.

1991-01-01

The Environmental Protection Agency (EPA) estimates the US currently generates about 160 million tons of municipal solid waste (MSW) per year, and this figure will exceed 200 million tons annually by the year 2000. About 80 percent of the MSW will be disposed of in landfills and waste-to-energy (WTE) facilities, both of which generate greenhouse gases, namely methane and carbon dioxide. This paper provides an introductory level analysis of the potential long term greenhouse gas emissions from these two MSW disposal alternatives. Carbon dioxide credits are derived for fossil fuel offset by WTE and methane emissions are converted to equivalent CO 2 emissions in order to derive a single emission figure for comparison of the greenhouse contribution of the two disposal strategies. A secondary analysis is presented to compare the net equivalent CO 2 emissions from WTE facilities to those from landfills with methane gas recovery, combustion and energy generation. The conclusion is, that for a given amount of MSW, landfilling contributes to the greenhouse effect about 10 times more than a modern Waste-To-Energy facility. Even with 50% of all landfill methane emissions recovered and converted to electricity, the contribution to the greenhouse effect by the landfill alternative is about 6 times greater than the waste-to-energy alternative

Cardiovascular responses to microinjections of GABA or anesthetics into the rostral ventrolateral medulla of conscious and anesthetized rats

Directory of Open Access Journals (Sweden)

Lacerda J.E.C.

2003-01-01

Full Text Available The rostral ventrolateral medulla (RVLM contains neurons involved in tonic and reflex control of arterial pressure. We describe the effects of gamma-aminobutyric acid (GABA and anesthetics injected into the RVLM of conscious and urethane (1.2 g/kg, iv anesthetized Wistar rats (300-350 g. In conscious rats, bilateral microinjection of GABA (50 nmol/200 nl induced a small but significant decrease in blood pressure (from 130 ± 3.6 to 110 ± 5.6 mmHg, N = 7. A similar response was observed with sodium pentobarbital microinjection (24 nmol/200 nl. However, in the same animals, the fall in blood pressure induced by GABA (from 121 ± 8.9 to 76 ± 8.8 mmHg, N = 7 or pentobarbital (from 118 ± 4.5 to 57 ± 11.3 mmHg, N = 6 was significantly increased after urethane anesthesia. In contrast, there was no difference between conscious (from 117 ± 4.1 to 92 ± 5.9 mmHg, N = 7 and anesthetized rats (from 123 ± 6.9 to 87 ± 8.7 mmHg, N = 7 when lidocaine (34 nmol/200 nl was microinjected into the RVLM. The heart rate variations were not consistent and only eventually reached significance in conscious or anesthetized rats. The right position of pipettes was confirmed by histology and glutamate microinjection into the RVLM. These findings suggest that in conscious animals the RVLM, in association with the other sympathetic premotor neurons, is responsible for the maintenance of sympathetic vasomotor tone during bilateral RVLM inhibition. Activity of one or more of these premotor neurons outside the RVLM can compensate for the effects of RVLM inhibition. In addition, the effects of lidocaine suggest that fibers passing through the RVLM are involved in the maintenance of blood pressure in conscious animals during RVLM inhibition.

Occurrence of paresthesia after dental local anesthetic administration in the United States.

Science.gov (United States)

Garisto, Gabriella A; Gaffen, Andrew S; Lawrence, Herenia P; Tenenbaum, Howard C; Haas, Daniel A

2010-07-01

Several studies have suggested that the likelihood of paresthesia may depend on the local anesthetic used. The purpose of this study was to determine if the type of local anesthetic administered had any effect on reports of paresthesia in dentistry in the United States. The authors obtained reports of paresthesia involving dental local anesthetics during the period from November 1997 through August 2008 from the U.S. Food and Drug Administration Adverse Event Reporting System. They used chi(2) analysis to compare expected frequencies, on the basis of U.S. local anesthetic sales data, with observed reports of oral paresthesia. During the study period, 248 cases of paresthesia occurring after dental procedures were reported. Most cases (94.5 percent) involved mandibular nerve block. The lingual nerve was affected in 89.0 percent of cases. Reports involving 4 percent prilocaine and 4 percent articaine were 7.3 and 3.6 times, respectively, greater than expected (chi(2), P paresthesia occurs more commonly after use of 4 percent local anesthetic formulations. These findings are consistent with those reported in a number of studies from other countries. Until further research indicates otherwise, dentists should consider these results when assessing the risks and benefits of using 4 percent local anesthetics for mandibular block anesthesia.

Influence of Ventilation Strategies and Anesthetic Techniques on Regional Cerebral Oximetry in the Beach Chair Position: A Prospective Interventional Study with a Randomized Comparison of Two Anesthetics.

Science.gov (United States)

Picton, Paul; Dering, Andrew; Alexander, Amir; Neff, Mary; Miller, Bruce S; Shanks, Amy; Housey, Michelle; Mashour, George A

2015-10-01

Beach chair positioning during general anesthesia is associated with cerebral oxygen desaturation. Changes in cerebral oxygenation resulting from the interaction of inspired oxygen fraction (FIO2), end-tidal carbon dioxide (PETCO2), and anesthetic choice have not been fully evaluated in anesthetized patients in the beach chair position. This is a prospective interventional within-group study of patients undergoing shoulder surgery in the beach chair position that incorporated a randomized comparison between two anesthetics. Fifty-six patients were randomized to receive desflurane or total intravenous anesthesia with propofol. Following induction of anesthesia and positioning, FIO2 and minute ventilation were sequentially adjusted for all patients. Regional cerebral oxygenation (rSO2) was the primary outcome and was recorded at each of five set points. While maintaining FIO2 at 0.3 and PETCO2 at 30 mmHg, there was a decrease in rSO2 from 68% (SD, 12) to 61% (SD, 12) (P positioning. The combined interventions of increasing FIO2 to 1.0 and increasing PETCO2 to 45 mmHg resulted in a 14% point improvement in rSO2 to 75% (SD, 12) (P position. There was no significant interaction effect of the anesthetic at the study intervention points. Increasing FIO2 and PETCO2 resulted in a significant increase in rSO2 that overcomes desaturation in patients anesthetized in the beach chair position and that appears independent of anesthetic choice.

Microbial gas generation under expected Waste Isolation Pilot Plant repository conditions

Energy Technology Data Exchange (ETDEWEB)

Francis, A.J.; Gillow, J.B.; Giles, M.R. [Brookhaven National Lab., Upton, NY (United States). Dept. of Applied Science

1997-03-01

Gas generation from the microbial degradation of the organic constituents of transuranic waste under conditions expected at the Waste Isolation Pilot Plant (WIPP) repository was investigated at Brookhaven National Laboratory. The biodegradation of mixed cellulosics (various types of paper) and electron-beam irradiated plastic and rubber materials (polyethylene, polyvinylchloride, neoprene, hypalon, and leaded hypalon) was examined. The rate of gas production from cellulose biodegradation in inundated samples incubated for 1,228 days at 30 C was biphasic, with an initial rapid rate up to approximately 600 days incubation, followed by a slower rate. The rate of total gas production in anaerobic samples containing mixed inoculum was as follows: 0.002 mL/g cellulose/day without nutrients; 0.004 mL/g cellulose/day with nutrients; and 0.01 mL/g cellulose/day in the presence of excess nitrate. Carbon dioxide production proceeded at a rate of 0.009 {micro}mol/g cellulose/day in anaerobic samples without nutrients, 0.05 {micro}mol/g cellulose/day in the presence of nutrients, and 0.2 {micro}mol/g cellulose/day with excess nitrate. Adding nutrients and excess nitrate stimulated denitrification, as evidenced by the accumulation of N{sub 2}O in the headspace (200 {micro}mol/g cellulose). The addition of the potential backfill bentonite increased the rate of CO{sub 2} production to 0.3 {micro}mol/g cellulose/day in anaerobic samples with excess nitrate. Analysis of the solution showed that lactic, acetic, propionic, butyric, and valeric acids were produced due to cellulose degradation. Samples incubated under anaerobic humid conditions for 415 days produced CO{sub 2} at a rate of 0.2 {micro}mol/g cellulose/day in the absence of nutrients, and 1 {micro}mol/g cellulose/day in the presence of bentonite and nutrients. There was no evidence of biodegradation of electron-beam irradiated plastic and rubber.

Dual effect of local anesthetics on the function of excitable rod outer segment disk membrane

Energy Technology Data Exchange (ETDEWEB)

Mashimo, T.; Abe, K.; Yoshiya, I.

1986-04-01

The effects of local anesthetics and a divalent cation, Ca2+, on the function of rhodopsin were estimated from the measurements of light-induced proton uptake. The light-induced proton uptake by rhodopsin in the rod outer segment disk membrane was enhanced at lower pH (4) but depressed at higher pHs (6 to 8) by the tertiary amine local anesthetics lidocaine, bupivacaine, tetracaine, and dibucaine. The order of local anesthetic-induced depression of the proton uptake followed that of their clinical anesthetic potencies. The depression of the proton uptake versus the concentration of the uncharged form of local anesthetic nearly describes the same curve for small and large dose of added anesthetic. Furthermore, a neutral local anesthetic, benzocaine, depressed the proton uptake at all pHs between 4 and 7. These results indicate that the depression of the proton uptake is due to the effect of only the uncharged form. It is hypothesized that the uncharged form of local anesthetics interacts hydrophobically with the rhodopsin in the disk membrane. The dual effect of local anesthetics on the proton uptake, on the other hand, suggests that the activation of the function of rhodopsin may be caused by the charged form. There was no significant change in the light-induced proton uptake by rhodopsin when 1 mM of Ca2+ was introduced into the disk membrane at varying pHs in the absence or presence of local anesthetics. This fact indicates that Ca2+ ion does not influence the diprotonating process of metarhodopsin; neither does it interfere with the local anesthetic-induced changes in the rhodopsin molecule.

Diagnosis of solid waste of oil and natural gas exploration and production activities in Brazil offshore sedimentary basins; Diagnostico dos residuos solidos das atividades de exploracao e producao de petroleo e gas natural em bacias sedimentares maritimas no Brasil

Energy Technology Data Exchange (ETDEWEB)

Koehler, Pedro Henrique Wisniewski; Mendonca; Gilberto Moraes de

2012-07-01

The objective of this study is to analyze the generation and disposal of solid waste from the exploration and production activities of oil and natural gas in Brazilian waters. We used data from the implementation reports of pollution control project of the activities licensed by IBAMA. During 2009 the activities related to exploration and production of offshore oil and gas produced a total of 44,437 tons of solid waste, with the main waste generated corresponding to: oily waste (16,002 t); Metal uncontaminated (11,085 t); contaminated waste (5630 t), non recycling waste (4935 t); Wood uncontaminated (1,861 t), chemicals (1,146 t). Considering the total waste generated by activities during the period analyzed, it was observed that 54.3% are made up of waste Class I (hazardous waste), 27.9% of Class II wastes (waste non-hazardous non-inert); and 17.8% of waste Class IIB (non-hazardous and inert waste). The results obtained in this work enabled the scenario of waste generation by the E and P offshore activities. As a result, the survey serves as a starting point for monitoring the progress in implementing the projects sought Pollution Control of licensed projects, as well as support the monitoring of reflexes arising from the intensification of activities in certain regions. (author)