Waste Disposition Research Articles

Household Waste Management; Voices of Residents of Anaocha Local Government Area of Anambra State, Nigeria

Background: Waste management is the generation, prevention, characterization, monitoring, treatment, handling, reuse and residual disposition of social waste. The various methods of waste disposal include: recycling, composting, barging, burying, landfills method, incineration, and the use of mechanical destructors. Objective: The aim of this study was to assess the knowledge, attitude and practice of house hold waste management among the respondents and the factors affecting their choice of method. Methodology: This was a cross sectional descriptive study. There were 270 respondents. The study was carried out among households in Anaocha LGA of Anambra state. The study made use of a semi-structured interviewer administered questionnaire. Result: Majority had good knowledge of waste management and portrayed good attitude towards waste management practices. The commonest method of waste disposal practiced by the community was burning and majority practiced the various methods because the methods were convenient for them. Conclusion: The study showed that people, despite having good knowledge and attitude towards waste management still practiced wrong methods.

Traceable Determination of the Absolute <newline/>Neutron Emission Yields of <formula formulatype="inline"><tex Notation="TeX">${{\rm UO}_2}{{\rm F}_2}$</tex></formula> <newline/>Working Reference Materials

The nuclear material contained in the process equipment of a uranium enrichment plant (referred to as holdup) is an important component of the overall nuclear material inventory for the plant. Accurate quantification and verification of holdup is needed to improve international safeguards and nuclear material accountancy. This is also needed for criticality safety and waste disposition. Passive neutron and gamma-ray nondestructive assay (NDA) methods are used to measure the holdup in process equipment. A key advantage of neutron measurements is that neutrons are highly penetrating and can be measured through thick walled equipment. The dominant source of neutrons in the UO2F2 holdup is from the 19F(α,n)22Na reaction resulting from 234U alpha decay when uranium is enriched. There is a considerable spread between different historic determinations of the 19F(α,n) yield from uranium which limits the accuracy of modeling and the calibration of NDA instruments. Furthermore, the compound form and presence of water also significantly affects the neutron emission rate from the holdup. This paper describes a series of experimental measurements performed at Los Alamos National Laboratory (LANL) to determine the absolute neutron emission yield from 10 different UO2F2 working reference materials (WRMs) fabricated at the Portsmouth Gaseous Diffusion Plant (PGDP). The Mini Epithermal Neutron Multiplicity Counter (Mini ENMC) and a NIST certified 252Cf neutron source were used for these measurements. The high efficiency and short die-away time of the Mini ENMC provides the high measurement precision needed to certify the neutron emission yield. The experiment was designed to achieve sub 1% accuracy in the net counting rate on each item and to provide assurance that important factors such as instrument stability, item placement and background were well understood. The traceable neutron yields measured from the WRMs were used to determine a more accurate neutron yield for the UO2F2 material. The results were compared to historical neutron emission rates. The F(α,n) data obtained from these measurements directly supports nuclear safeguards for NDA of uranium holdup and provides a more accurate calibration for new and existing NDA detector systems.

Collection and Disposition of Solid Waste in the Metropolitan Area of Belo Horizonte (Brazil)

Collection and Disposition of Solid Waste in the Metropolitan Area of Belo Horizonte (Brazil)

An Overview and Recent Developments of Distinct Lattice Spring Model on Dynamic Fracturing of Rock

This paper presents some recent developments of the Distinct Lattice Spring Model (DLSM) on dynamic fracturing of rock. The DLSM is a micromechanics based discrete numerical model for rock dynamics problems. It provides an alternative tool for rock mechanics study. Compared with the classical Discrete Element Model (DEM), the DLSM can directly use macroscopic parameters without any requirement for calibration process. Another significant advantage is that the DLSM uses only half of the degree of freedoms, and therefore, is more computational efficient. Because of these advantages, it has been used in a number of fields, e.g., dynamic fracturing, wave propagation, and nuclear waste disposition. In this work, the basic principles of the DLSM and its latest developments will be outlined.

Experimental determination of the speciation, partitioning, and release of perrhenate as a chemical surrogate for pertechnetate from a sodalite-bearing multiphase ceramic waste form

A key component to closing the nuclear fuel cycle is the storage and disposition of nuclear waste in geologic systems. Multiphase ceramic waste forms have been studied extensively as a potential host matrix for nuclear waste. Understanding the speciation, partitioning, and release behavior of radionuclides immobilized in multiphase ceramic waste forms is a critical aspect of developing the scientific and technical basis for nuclear waste management. In this study, we evaluated a sodalite-bearing multiphase ceramic waste form (i.e., fluidized-bed steam reform sodium aluminosilicate [FBSR NAS] product) as a potential host matrix for long-lived radionuclides, such as technetium (99Tc). The FBSR NAS material consists primarily of nepheline (ideally NaAlSiO4), anion-bearing sodalites (ideally M8[Al6Si6O24]X2, where M refers to alkali and alkaline earth cations and X refers to monovalent anions), and nosean (ideally Na8[AlSiO4]6SO4). Bulk X-ray absorption fine structure analysis of the multiphase ceramic waste form, suggest rhenium (Re) is in the Re(VII) oxidation state and has partitioned to a Re-bearing sodalite phase (most likely a perrhenate sodalite Na8[Al6Si6O24](ReO4)2). Rhenium was added as a chemical surrogate for 99Tc during the FBSR NAS synthesis process. The weathering behavior of the FBSR NAS material was evaluated under hydraulically unsaturated conditions with deionized water at 90°C. The steady-state Al, Na, and Si concentrations suggests the weathering mechanisms are consistent with what has been observed for other aluminosilicate minerals and include a combination of ion exchange, network hydrolysis, and the formation of an enriched-silica surface layer or phase. The steady-state S and Re concentrations are within an order of magnitude of the nosean and perrhenate sodalite solubility, respectively. The order of magnitude difference between the observed and predicted concentration for Re and S may be associated with the fact that the anion-bearing sodalites contained in the multiphase ceramic matrix are present as mixed-anion sodalite phases. These results suggest the multiphase FBSR NAS material may be a viable host matrix for long-lived, highly mobilie radionuclides which is a critical aspect in the management of nuclear waste.

Uso de hábitat por aves en rellenos sanitarios del noreste de la provincia de Buenos Aires, Argentina

(Palabras clave: residuos, gaviotas, palomas, ambientes disturbados, antropizacion y avifauna, rellenos sanitarios) ABSTRACT. Habitat use by birds in landfills of northeastern Buenos Aires province, Argentina: Rubbish dumps and landfills are attractive sites for different species of opportunistic birds which can increase their populations on the food supplement offered by organic waste. These birds can act like vectors of diseases or polluting agents, damage agriculture, increase the risk of bird strikes, and have negative effects on other species through competition or predation. The goals of this work are to identify and quantify the species of birds and their habitat use within three landfills of the northeast of the Buenos Aires province, and to determine the importance of the waste amount deposited on these variables during two consecutive winter periods. Total bird abundance was different between landfills in both winters, and gulls predominated in the three landfills. North 3 landfill had the greater abundance of gulls and doves. Wading birds were significantly more abundant in Gonzalez Catan Landfill, and the birds of prey had similar abundances in the three landfills in both periods. In both periods, the gulls were abundant in all habitats of three landfills, whereas only the abundance of doves in North 3 landfill was related to the final waste disposition sites and to the near edge (<200m) area. Exposed waste in surface was positively correlated with total bird abundance and the abundance of doves, which are themselves related to the daily amount waste deposited. Reduction of the organic portion and waste handling during the final disposition, habitat management around the final disposition sites, together with both passive and active direct control methods would reduce the abundance of birds in landfills and their negative potential effects on man and the environment.

Incinerator Stop Operation Assessment and Municipal Solid Waste Disposition Adjustment

Incineration is the main way to dispose the municipal solid waste (MSW) in Taiwan. The amount of MSW is rapidly decreased during recent 10 years due to the policies implementation of waste reduction and resource recycle since 2003. Assessment of incinerator operation stop and transformation therefore becomes an essential issue. An evaluation framework was constructed and put into practice in this research. With the considerations of service status, operation performance, MSW treatment status and the impact level of stopping operation was integrated and assessed in the first stage. An optimal model was built for re-programming the MSW clean strategies of original service areas by taking account of MSW collection distance, design capacity of incinerators and the heating value of solid waste in the second stage. A case study was implemented for four incinerators in Kaohsiung City of southern Taiwan to demonstrate the feasibility of proposed assessment framework.

Configuring EM2 to Meet the Challenges of Economics, Waste Disposition and Non-Proliferation Confronting Nuclear Energy in the U.S.

General Atomics (GA) is developing a new nuclear concept called Energy Multiplier Module (EM2), which is a helium (He) cooled fast reactor with a net electrical output of 240 MW. It employs a “convert & burn” core design which converts fertile to fissile and burns it in situ over a 30-year core life. It can burn SNF from LWRs with no reprocessing, only refabrication. The core can be recycled using an AIROX-based method to remove a fraction of the fission products (FPs) but no heavy metals. The reactor is passively safe and sited below grade. It can sustain a Fukushima type station blackout or even a station blackout combined with a loss of coolant accident using only passive safety systems without radioactivity release or loss of plant. The afterheat is rejected directly to the air. It is a high temperature reactor and employs a direct closed-cycle gas turbine for 48% net efficiency. The reject heat can be released directly to air so that siting near a large water source is not required. GA is targeting a power cost in the range of 6-7 cents/kW-hr, which would make it a competitive power source even with low-cost natural gas. This ambitious power cost is achieved through high efficiency, simplicity of the direct cycle gas turbine power and relatively small subsystems that can be shop fabricated and shipped by road to the site.

Separation of Transmutation- and Fission-Produced Radioisotopes from Irradiated Beryllium

The primary objective of this study was to test the effectiveness of a two-step solvent extraction-precipitation process for separating transmutation and fission products from irradiated beryllium. Beryllium metal was dissolved in nitric and fluoroboric acids. Isotopes of 241Am, 239Pu, 85Sr, 60Co, and 137Cs were then added to make a surrogate beryllium waste solution. A series of batch contacts was performed with the spiked simulant using chlorinated cobalt dicarbollide and polyethylene glycol diluted with sulfone to extract the isotopes of Cs and Sr. Another series of batch contacts was performed using a combination of octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide in tributyl phosphate diluted with dodecane for extracting the isotopes of Pu and Am. The 60Co was separated by first forming a cobalt complex and then selectively precipitating the beryllium as a hydroxide. The results indicate that >99.9% removal can be achieved for each radionuclide. Transuranic isotope contamination levels are reduced to <100 nCi/g, and sources of high beta-gamma radiation (60Co, 137Cs, and 90Sr) are reduced to levels that will allow the beryllium to be contact handled. The separation process may be applicable to a recycle or waste disposition scenario.

Potencial de duas espécies de eucalipto na fitoestabilização de solo contaminado com zinco

Com o objetivo de avaliar a tecnica da fitoestabilizacao para remediar solo contaminado com zinco, foram utilizadas as especies Eucalyptus urophylla e Eucalyptus saligna em conjunto com os residuos siderurgicos escoria de aciaria e carepa de laminacao. O experimento foi realizado em casa de vegetacao na Universidade Federal Rural do Rio de Janeiro, utilizando-se um solo contaminado com Zn, coletado em area proxima ao patio de minerio do Porto de Itaguai e ao local de disposicao de residuo perigoso da Cia Mercantil e Industrial Inga em Itaguai-RJ. O substrato foi tratado com dois agentes inertizantes: um residuo industrial com caracteristica alcalina (escoria de aciaria) nas doses de 4 e 6% e outro com alto teor de oxido de ferro usado como adsorvente (carepa de laminacao), em dose unica de 1%. Apos o transplantio das mudas, foram feitas coletas do substrato para determinacao do pH e o fracionamento de Zn nas diferentes formas quimicas. Verificou-se que o substrato, nao tratado, apresentava alto teor de zinco nas fracoes fitodisponiveis. Os tratamentos causaram a reducao nas concentracoes de Zn nas formas quimicas hidrossoluveis e trocaveis e aumento nas fases mais estaveis. A menor dose de escoria de aciaria foi suficiente para provocar diminuicao nas concentracoes de zinco em solucao, sendo esse efeito evidenciado pelo desenvolvimento das plantas, enquanto a maior dose de escoria de aciaria promoveu maior crescimento das especies. A especie que obteve melhor desenvolvimento foi o E. urophylla, entretanto, a que apresentou maior acumulo total de Zn foi o E. saligna.

Bioplastic Wastes: The Best Final Disposition for Energy Saving

The pressing need to reduce the consumption of non-renewable resources and the emission of greenhouse gases into the environment, in recent decades has led to the wide development of bio-based plastics that are produced from renewable sources, such as corn, wheat, oil seeds etc. Actually, the most important bio-based plastics on the market are the poly(lactic acid) (PLA) produced from Nature Works (USA) and the Mater-Bi, a starch based bioplastics, made from Novamont (Italy). The aim of this work is not only to assess the actual energy and greenhouse gases (GHGs) savings resulting from the production of bioplastics, compared with the production of conventional plastics, but also to analyze what might be the best final disposition of bioplastic wastes in order to maximize the energy saving. Therefore, by using the Life Cycle Assessment (LCA) methodology, LCAs cradle to gate and cradle to grave were carried out both for PLA and Mater-Bi, taking into consideration as final scenarios composting, incineration, anaerobic digestion and mechanical recycling processes. The work demonstrates how incineration, composting and anaerobic digestion processes are clearly under-performing, from an environmental point of view, with respect to the mechanical recycling process.

Earthworm avoidance of biochar can be mitigated by wetting

Biochar has a great potential for enhancing soil fertility and carbon sequestration while enabling beneficial waste disposition. Because of the potential for widespread application, it is essential to proactively assess and mitigate any unintended consequences associated with soil biochar amendment. We conducted soil avoidance tests, growth and reproduction tests, and oxidative stress assays with the earthworm Eisenia foetida to assess the potential toxicity of soil amended with biochar produced from apple wood chips. Earthworms avoided soils containing 100 and 200 g/kg dry biochar at statistically significant levels ( p < 0.05), and after 28-day incubation, these earthworms lost more weight than those in control (unamended) soil. However, biochar did not affect the reproduction of earthworms. We investigated whether the observed avoidance was due to nutrition deficiency, desiccation, or the presence of toxic polynuclear aromatic hydrocarbons (PAHs) formed during biochar production by pyrolysis. Nutrition deficiency was excluded by the lack of earthworm avoidance to soil amended with nutrient-deficient sand instead of biochar. Although traces of PAH were detected in the tested biochar (e.g., 25.9 μg/kg fluorene, 3290 μg/kg naphthalene, and 102 μg/kg phenanthrene), the lack of lipid peroxidation and no increase in superoxide dismutase activity in biochar-exposed earthworms suggests that presence of toxic compounds was not a likely reason for avoidance. Furthermore, wetting the biochar to its field capacity resulted in statistically undetectable avoidance relative to control soil, indicating that insufficient moisture could be a key factor affecting earthworm behavior in soil amended with dry biochar. To avoid desiccation of invertebrates and enable their beneficial ecosystem services, we recommend wetting biochar either before or immediately after soil application.

Environmental mineralogy – Understanding element behavior in ecosystems

Environmental Mineralogy has developed over the past decade in response to the recognition that minerals are linked in many important ways with the global ecosystem. Minerals are the main repositories of the chemical elements in Earth's crust and thus are the main sources of elements needed for the development of civilization, contaminant and pollutant elements that impact global and local ecosystems, and elements that are essential plant nutrients. These elements are released from minerals through natural processes, such as chemical weathering, and anthropogenic activities, such as mining and energy production, agriculture and industrial activities, and careless waste disposal. Minerals also play key roles in the biogeochemical cycling of the elements, sequestering elements and releasing them as the primary minerals in crustal rocks undergo various structural and compositional transformations in response to physical, chemical, and biological processes that produce secondary minerals and soils. These processes have resulted in the release of toxic elements such as arsenic in groundwater aquifers, which is having a major impact on the health of millions of people in South and Southeast Asia. The interfaces between mineral surfaces and aqueous solutions are the locations of most chemical reactions that control the composition of the natural environment, including the composition of natural waters. The nuclear fuel cycle, from uranium mining to the disposition of high-level nuclear waste, is also intimately related to minerals. A fundamental understanding of these processes requires molecular-scale information about minerals, their bulk structures and properties such as solubility, their surfaces, and their interactions with aqueous solutions, atmospheric and soil gases, natural organic matter, and biological organisms. Gaining this understanding is further complicated by the presence of natural, incidental, and manufactured nanoparticles in the environment, which are becoming increasingly important due to the rapidly developing field of nanotechnology. As a result of this complexity, Environmental Mineralogy requires the use of the most modern molecular-scale analytical and theoretical methods and overlaps substantially with closely related fields such as Environmental Sciences, low-temperature Geochemistry, and Geomicrobiology. This paper provides brief overviews of the above topics and discusses the complexity of minerals, natural vs. anthropogenic inputs of elements and pollutants into the biosphere, the role of minerals in the biogeochemical cycling of elements, natural nanoparticles, and the Environmental Mineralogy of three major potential pollutant elements (Hg, As and U).

RESULTS OF EXTERNAL TECHNICAL REVIEWS OF SITE MODELING EFFORTS THAT SUPPORT SYSTEM PLANS

An External Technical Review (ETR) team evaluated the system-level modeling and simulation tools in support of Savannah River Site and Office of River Protection liquid waste processing and disposal systems. The reviews focused on the following primary areas: software and modeling tools, capability to model needed facilities and operations, rate at which predictions are performed, and need for additional tools. The Liquid Waste Disposition Systems at these sites are highly integrated operations that involve safely storing liquid waste in underground storage tanks; removing, treating, and disposing low-activity fraction on-site; vitrifying high-level waste; and storing the vitrified waste until permanent disposition at a Federal Repository. The purpose of the ETR team was to evaluate the current process simulation tools that support the planning basis for life cycle liquid waste disposition system plans. These plans establish a base for processing the constituents of liquid waste systems to the end of the program mission. Observations and recommendations were made for each of the review areas. In general, tools appear to provide reasonable estimates for their intended purposes; however, additional functionality and new tools are needed, as well as greater flexibility and improved performance in producing estimates for planning purposes.

The Analysis of Factors on the Development of Construction and Demolition Waste Disposition Industrialization in China

The Analysis of Factors on the Development of Construction and Demolition Waste Disposition Industrialization in China

Generación y gestión de residuos sólidos ordinarios en la Universidad Nacional de Costa Rica: patrones cuantitativos y sociológicos

La Universidad Nacional (Costa Rica) estableció un programa de gestión ambiental que incluye un proyecto de manejo de residuos ordinarios. Este artículo evalúa el desempeño del proyecto durante el 2005; además se analiza experimentalmente y cuantitativamente el proceso. Los principales obstáculos fueron fallas de diseño en las estructuras de almacenaje, procedimientos inadecuados, contradicción entre lo que se planeaba hacer y lo que realmente se hacía, rotulación confusa y rechazo por parte del personal universitario debido a conflicto de intereses económicos, laborales y de percepción personal de estética. Ese año evaluado se envió a reciclar un total de 53 560 kg (media: 6 kg/persona). Predominaron papel y cartón (82% de los residuos), seguido de vidrio (8%), plástico (4%) y metales (2%) (no se consideró a los residuos orgánicos debido a problemas logísticos). La Oficina de Publicaciones fue la que más residuos produjo y hubo una tendencia a que con el tiempo aumentara la contribución extrauniversitaria (vecinos, funcionarios y estudiantes que traían residuos de sus casas). La ubicación correcta de los residuos mejoró tras un cambio en la rotulación de los contendores problemáticos (Papel 96-95%, No reciclables 88-90% y Varios que fue cambiado a Envases –para plásticos, vidrio y aluminio– de 51 a 75%). La mejoría en la separación de los residuos se debe probablemente al trabajo de educación y a mejoras en la organización y rotulación. A mediados del periodo los residuos enviados al relleno sanitario tuvieron un promedio diario de 606,7kg, pero solo el 3,6% era material reciclable, principalmente plásticos y papel. Los sitios en donde se almacenaba el material no reciclable para envío al relleno tuvieron menos higiene cuando las barreras contra vertebrados dificultaban su limpieza. Al diseñar este tipo de proyectos es necesario considerar a todos los actores sociales para evitar conflictos por funciones laborales y entradas económicas. El beneficio de este tipo de proyecto debe verse desde una perspectiva mas amplia, ya que dependiendo de las condiciones de cada país es posible que no se produzca ingreso económico real.

Right answers and right-wrong answers: Sources of information influencing knowledge of nuclear-related information

Surveys in 2008 and 2009 asked almost 6000 United States residents to indicate their knowledge about the use of nuclear and other sources of energy, and the disposition of nuclear waste. Less than 10% of respondents knew where spent commercial nuclear fuel is stored. With regard to knowledge about fuel for electrical energy, respondents overestimated solar and wind use and underestimated coal use. These responses are consistent with mass media coverage of these issues. The mass media were the source of information for the vast majority of respondents. However, the likelihood of right answers to our questions increased as reliance on the mass media decreased, and it increased with use of books, magazines, personal contacts and the web. Educated affluent white males with strong preferences for nuclear energy disproportionately were knowledgeable. These observations demonstrate the daunting challenge of providing information about subjects that are largely distant and disconnected from the public’s lives. The Department of Energy, Nuclear Regulatory Commission, state and local health, environmental and energy agencies, and facility owners and operators have huge domestic political, national security and economic stakes in improving the factual grounding of public reactions to energy production and waste management choices.

HAZARDOUS WASTE: GAO Grades Hanford Cleanup

HAZARDOUS WASTE: GAO Grades Hanford Cleanup

A Sustainable Nuclear Fuel Cycle Based on Laser Inertial Fusion Energy

The National Ignition Facility (NIF), a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, will soon be completed at the Lawrence Livermore National Laboratory. Experiments designed to accomplish the NIF’s goal will commence in 2010, using laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 35 MJ are expected soon thereafter. We propose that a laser system capable of generating fusion yields of 35 to 75 MJ at 10 to 15 Hz (i.e., ≈ 350- to 1000-MW fusion and ≈ 1.3 to 3.6 x 1020 n/s), coupled to a compact subcritical fission blanket, could be used to generate several GW of thermal power (GWth) while avoiding carbon dioxide emissions, mitigating nuclear proliferation concerns and minimizing the concerns associated with nuclear safety and long-term nuclear waste disposition. This Laser Inertial Fusion Energy (LIFE) based system is a logical extension of the NIF laser and the yields expected from the early ignition experiments on NIF. The LIFE concept is a once-through, self-contained closed fuel cycle and would have the following characteristics: (1) eliminate the need for uranium enrichment; (2) utilize over 90% of the energy content of the nuclear fuel; (3) eliminate the need for spent fuel chemical separation facilities; (4) maintain the fission blanket subcritical at all times (keff <0.90); and (5) minimize future requirements for deep underground geological waste repositories and minimize actinide content in the end-of-life nuclear waste below the (the lowest). Options to burn natural or depleted U, Th, U/Th mixtures, Spent Nuclear Fuel (SNF) without chemical separations of weapons-attractive actinide streams, and excess weapons Pu or highly enriched U (HEU) are possible and under consideration. Because the fission blanket is always subcritical and decay heat removal is possible via passive mechanisms, the technology is inherently safe. Many technical challenges must be met, but a LIFE solution could provide a sustainable path for worldwide growth of nuclear power for electricity production and hydrogen generation.

Corrosion Testing of Nickel and Titanium Alloys for Nuclear Waste Disposition

Abstract Extensive testing has been performed at the Lawrence Livermore National Laboratory (LLNL, Livermore, California) to determine the corrosion characteristics of nickel-based alloys such as A...