Tank Waste Research Articles

Incorporation of trace metals in Hanford waste boehmite mineral phases and dissolution rate impacts

AbstractData from radioactive Hanford tank waste samples was analyzed to assess whether trace metals present were incorporated into the bulk boehmite matrix or were simply intermingled with the bulk material and subsequent impacts to the boehmite dissolution rate. Results suggest that chromium is primarily blended into the bulk boehmite, with a small fraction present on the surface of the solids. However, increasing the level of chromium incorporation 30‐fold decreased the dissolution rate of boehmite by only 8%, suggesting incorporation of chromium into these samples had a minimal impact on the dissolution rate. Iron was also found to be incorporated in the boehmite solids. Silicon appears to be simply intermingled and not blended into the boehmite crystals.

Attitudes and Practice of Solid Waste Management among Residents of Federal Capital Territory Municipal Council, Nigeria

Background: Attitude is a major determinant of health behaviour. Proper management of solid waste at the household level can only be achieved by identifying the attitude of residents towards household solid waste management practices. Solid wastes (SW) are materials created from human activities that are no longer useful. They are disposable solid materials and might be hazardous to human well-being, e.g. plastics, wood, food, textiles, metals, glass, leather, sanitary waste, septic tank waste, etc. Aim: This study assessed the attitude of Abuja residents towards solid waste management practices in the Federal Capital Territory (FCT) Municipal Council. Method: A cross-sectional survey design was used for the study. The respondents for the study were adults from randomly selected households in the AMAC and Bwari suburbs of Abuja FCT. Data was collected from 197 respondents using a self-structured questionnaire (α=0.78). Data was analysed using SPSS version 25.0 Findings: The study showed that the residents of the FCT municipal agreed that organic and plastic materials are the most solid waste materials produced. There was a positive attitude towards waste collection through waste bins (mean value: 2.79, SD: 1.214) but a very poor attitude towards separation of solid wastes before final disposal (mean value: 1.45, SD: 0.939). Conclusion: Despite having a favourable attitude towards collecting their solid wastes in waste baskets (bins) and plastic bags and temporary storage of their solid waste before disposal, 47.2% of FCT residents still dump refuse along the roadside and have a very poor attitude towards separating solid wastes before final disposal. Keywords: Solid waste, Management practices, FCT Municipal council, Solid Waste Management

Knowledge, attitude and practice on water, sanitation and hygiene (WASH) and COVID-19 among households in rural Bangladesh

Enhanced water, sanitation, and hygiene (WASH) conditions can significantly reduce the incidence of communicable diseases and deaths related to diarrhea by up to 65%. The US Centers for Disease Control and Prevention (CDC) advocates regular handwashing with soap and water for at least 20 seconds as an effective measure to mitigate the spread of COVID-19. This study aims to assess rural Bangladeshi households' perceptions and knowledge concerning the COVID-19 pandemic, as well as their understanding, attitudes, and practices regarding water, sanitation, and hygiene. A cross-sectional study was conducted between June 2020 and December 2020 to evaluate knowledge and practices related to safe water, sanitation, personal hygiene, and COVID-19 in rural Bangladesh. Self-administered questionnaires, pre-tested for reliability, were utilized to collect self-reported data, which were subsequently analyzed descriptively. Of the study participants, 66.78% were female, with a mean age of 40. The majority (92.36%) demonstrated adequate knowledge of personal hygiene, although 66.78% had not received hygiene education, and a significant proportion reported low levels of hygiene practices (17.28%). Nearly all respondents (98%) reported having access to a pit latrine, either with or without a seal, yet 63.12% indicated that their toilets become unusable during floods, and 29% admitted to practicing open defecation. While nearly all respondents were aware of the ongoing COVID-19 outbreak, only 46% had a comprehensive understanding of its transmission dynamics. Moreover, knowledge about preventive measures against the pandemic was found to be limited. Despite understanding the importance of handwashing, reported hand hygiene practices were inadequate among rural households. Additionally, a majority reported inadequate management of child feces, household waste, and sludge tanks. While awareness of the COVID-19 pandemic was high, a substantial proportion of respondents lacked understanding of its transmission and prevention methods. Moreover, fewer respondents reported using hand sanitizer when venturing outside for work. Future research should explore the impact of these behaviors on health outcomes and propose targeted interventions to improve hygiene practices. Jahangirnagar University J. Biol. Sci. 12(1 & 2): 11-21, 2023 (June & December)

Parameter Sensitivity Analysis for Long-Term Nuclide Migration in Granite Barriers Considering a 3D Discrete Fracture–Matrix System

As a geological barrier for high-level radioactive waste (HLW) disposal in China, granite is crucial for blocking nuclide migration into the biosphere. However, the high uncertainty associated with the 3D geological system, such as the stochastic discrete fracture networks in granite, significantly impedes practical safety assessments of HLW disposal. This study proposes a Monte Carlo simulation (MCS)-based simulation framework for evaluating the long-term barrier performance of nuclide migration in fractured rocks. Statistical data on fracture geometric parameters, on-site hydrogeological conditions, and relevant migration parameters are obtained from a research site in Northwestern China. The simulation models consider the migration of three key nuclides, Cs-135, Se-79, and Zr-93, in fractured granite, with mechanisms including adsorption, advection, diffusion, dispersion, and decay considered as factors. Subsequently, sixty MCS realizations are performed to conduct a sensitivity analysis using the open-source software OpenGeoSys-5 (OGS-5). The results reveal the maximum and minimum values of the nuclide breakthrough time Tt (12,000 and 3600 years, respectively) and the maximum and minimum values of the nuclide breakthrough concentration Cmax (4.26 × 10−4 mSv/a and 2.64 × 10−5 mSv/a, respectively). These significant differences underscore the significant effect of the uncertainty in the discrete fracture network model on long-term barrier performance. After the failure of the waste tank (1000 years), nuclides are estimated to reach the outlet boundary 6480 years later. The individual effective dose in the biosphere initially increases and then decreases, reaching a peak value of Cmax = 4.26 × 10−4 mSv/a around 350,000 years, which is below the critical dose of 0.01 mSv/a. These sensitivity analysis results concerning nuclide migration in discrete fractured granite can enhance the simulation and prediction accuracy for risk evaluation of HLW disposal.

Design and Implementation of Continuous Settling Tank (CST) Temperature Monitoring System and Waste Pond Level in a Palm Oil Mills

Design and Implementation of Continuous Settling Tank (CST) Temperature Monitoring System and Waste Pond Level in a Palm Oil Mills

Automated SEM analysis of particles in Hanford tank waste

Multiple bench-scale filtration campaigns of Hanford tank waste supernatant on a backpulseable dead-end filtration skid have provided greater insight into the solids that cause fouling and reduce filter performance. The solids collected during each campaign were concentrated from the backpulse solutions and examined using automated particle analysis (APA) methods with scanning electron microscopy and X-ray energy dispersive spectroscopy to categorize particle types and their morphological characteristics. We show that with APA, thousands of particles can be analyzed to provide accurate insight into the phases that may be impacting filter performance.

Long-Term Performance of Ag/AgCl Reference Electrodes for Corrosion Potential Monitoring in Radioactive Tank Waste at the Hanford Site

This work studied the exposure effects of radioactive tank waste on the long-term performance of single junction Ag/AgCl reference electrodes for corrosion potential monitoring at the Hanford Site. Electrodes from three manufacturers with very different designs were studied using open-circuit potential and electrochemical impedance measurements in radioactive tank waste. Post-test analyses were conducted on some failed electrodes using destructive and nondestructive techniques. The intrusion of the aggressive and radioactive chemicals in tank waste through the porous frit materials was the primary mechanism that led to the clogging of frit, physical and chemical degradation of AgCl bonded to Ag wire, and alteration of the internal electrolyte. Radiolytic chemical species such as H2O2 and HNO3 may have also induced the degradation of the Ag wire. The extent of electrode degradation and failure probability highly depended on the electrode design and environmental conditions. Chemicals in tank waste had stronger effects than radiation on the long-term performance of the Ag/AgCl reference electrodes.

The simultaneous removal of technetium and iodine from Hanford tank waste

The simultaneous removal of radionuclides technetium-99 and iodine-129 from an actual decontaminated Hanford tank waste sample (a mixture of decontaminated waste from tanks 241-AP-105 and 241-AP-107) was demonstrated for the first time in this work. A series of commercially available ion exchange resins were evaluated in batch contact tests in the tank waste, and all showed removal of both Tc and I. The highest Tc removal from the tank waste was observed for Purolite A530e while the highest iodine removal was observed for ResinTech SIR-110-MP. Isotherm tests in simulated tank waste with these two resins showed that the SIR-110-HP-MP had consistently higher Kd for both pertechnetate and iodide; with much higher Kd than previous works on Tc removal from Hanford waste. As such, the SIR-110-MP was evaluated in a dual-column (lead/lag) test processing 5.2L of the tank waste mixture showing 50 % breakthrough of Tc on the lead column and no significant breakthrough on the lag after 641 bed volumes (BV, 6 mL size) while significant iodine breakthrough (>50 %) occurred after 28 BV. The limited iodine uptake was attributed to the column conditions generating mass transfer limitations. A fraction of the Tc and I was not captured by the resin (<10 %) in either the batch tests or column tests. The iodine fraction is not iodate and is likely organo-iodide. The fraction of the Tc was identified as a non-pertechnetate species which is the first time non-pertechnetate has been identified in AP-105 and AP-107 tanks. This non-pertechnetate fraction contained Tc(I) and for the first time a stable Tc(VI) species in Hanford waste was identified..

New insight on the influence of surface-modified clay cup with stirring effect for bioelectricity production by utilizing septic tank wastewater

The removal of organic particulates from septic tank waste waters is the most crucial part of biological treatment processes. In this regard, the present study explores the potential applications of septic tank waste water treatment (STWW) system in the removal of organic matter and energy generation using Microbial fuel cells. The effect of acrylic varnish coating over the clay cup along with stirring (ACS- SMFC) has produced 70% more electricity than the uncoated clay cups without stirring, with the OCV of 984 ± 2 mV, current and power density of 706 ± 5.78 mA/m3 and 61.17 ± 0.29 mW/m3. The fabrication of the clay cup proves the presence of Niobium and chlorine functional groups in EDAX analysis, which affirms its high electron flow and superconductivity for better electricity production. SEM and confocal laser scanning microscopy affirmed the catabolic conversion of organic substrates of STWW through microbial communities of biofilm on bioelectricity production. Thus the higher COD removal value of 60.3 ± 0.09% was achieved in the ACS –SMFC module by utilizing STWW as substrate. Acrylic varnishing's efficacy on clay cups was confirmed via Fourier transform infrared spectroscopy with prominent peaks between 700 cm−1 to 3612 cm−1.

Numerical modeling of Joule heated ceramic melter

Computational fluid dynamics and heat transfer models of waste glass melters are being developed to support the vitrification campaign at the Waste Treatment and Immobilization Plant (WTP) as part of the United States nuclear waste stewardship and environmental protection programs. The WTP mission aims to achieve the stable and durable processing of vitrified waste in the safest, most efficient, and economical manner possible. Hanford’s tank waste is far more complex and varied than the waste treated by other vitrification facilities and both startup and long-term operational challenges are likely to be even greater than prior experience has shown. There are thousands of different waste compositions, which makes processing the waste a complex and challenging task. Models of test melters, pilot-scale, and full-scale melters have been developed to provide understanding and insight into the various physical and chemical phenomena occurring during vitrification. The results of these modeling activities will be used to support the WTP operations to process legacy nuclear waste into a stable form for disposal.

Boiling and Drying Accident of High-Level Liquid Waste in a Reprocessing Plant: Examination of the Time-Dependent Temperature Increase of the Waste and of the Generation Rates of the Individual Components Released into the Gas Phase

Using the amount, composition, and decay power density of high-level liquid waste in a storage tank, the temperature change of the waste up to 600°C and the corresponding vapor and gas release rates of H2O, HNO3, NO2, NO, and O2 as a function of time after the loss of cooling function were obtained by the following method. The heat balance equations in and around the tank were derived, and the solution of the waste temperature change was numerically obtained using the vaporization rates of H2O and HNO3 and the generation rate of NOx, which were both obtained from the experiments using the simulated liquid waste. Utilizing the temperature versus time curve obtained from the equation, the release rates of the components described above were obtained as a function of time. This information on the progress of the accident can be used to study the Leak Path Factor of radioactive materials, especially of volatilized Ru, and further, it becomes basic information when considering accident management and suppressing the impact of a disaster.

Ticari buzağı mamalarının mikrobiyolojik analizi ve izole edilen Enterococcus türlerinde antibiyotik dirençliliği

One of the reasons why calf milk replacer is preferred over unpasteurized bulk tank milk or waste milk with antibiotics on farms is that it prevents epidemic diseases and antibiotic resistance that may occur on the farm. In this study analyzed commercial calf milk replacer products (n = 12) obtained from dairy farms around Turkiye by microbiological culture and polymerase chain reaction (PCR). In order to evaluate the microbiological quality of calf milk replacer, total bacteria count, coliform E. coli and E. coli O157-H7, Salmonella spp., Staphylococcus spp., Streptococcus spp., Enterococcus spp. analyses were performed according to microbiological analysis methods determined according to ISO standards. Enterococcus spp. was isolated from all 12 calf milk replacer samples analyzed and molecularly confirmed by PCR with the presence of the gross-Es gene. Salmonella spp., E. coli, Staphylococcus spp. and Streptococcus spp. were not isolated from the samples.&#x0D; Additionally, in the bacterial counts, an average of 5.3x107 Enterococci were counted from all samples in 1 gram of calf milk replacer. Antimicrobial analysis of the isolated bacteria was completed according to CLSI 2022 data, and 11 isolates were defined as multi drug resistance and one isolate was defined as extensive drug resistance. It was also determined that the isolate defined as extensive drug resistance was resistant to Vancomycin and carried the Van A resistance gene. Many proteins used in the preparation of calf milk replacers are of animal origin and may contain pathogenic bacteria. Milk replacers are used on most farms for biosecurity purposes. It is known that milk replacers affect microbiota. It was shown in this study that if calf milk replacers are not prepared under the regulations, they may cause harm rather than benefit to on-farm biosecurity factors. It is concerning that calves are given calf milk replacers containing antibiotic-resistant Enterococcus spp. to sustain their lives when they are most vulnerable to disease during the window of susceptibility. When using calf milk replacer in calf feeding, field veterinarians should be informed about the microbiological certification of the product and provide information about pasteurization and presentation for consumption.

Triple-objective MPSO of zeotropic-fluid solar ejector cycle integrated with cold storage tank based on techno-economic criteria

The current study objective is to optimize the integration of a solar ejector cycle with cold storage by applying a multi-objective modified particle swarm optimization technique. Various collector and working fluid's effects are evaluated on dynamic system behavior, which zeotropic fluid and parabolic trough collector have been the most effective choices. Hot and cold storage tanks are applied to overcome the instability of solar energy and ensure sustainable access to produced cold. Design parameter's optimum values are estimated through sensitivity analysis and genetic algorithm optimization which are decreased up to 70% compared to initial guesses. An artificial neural network is employed to train exergo-economic-environmental data which fed into the multi-objective modified particle swarm optimization algorithm. With using of cold storage tank, the system's coefficient of performance is enhanced up to three times compared to the ejector cycle at optimum design variable. By employing of parabolic trough collector, the system has its maximum coefficient of performance and exergy efficiency, as well as the minimum size of the ejector cycle and cold storage tank. The parabolic trough collector, air handling unit, and cold storage tank waste over 80% of the overall system's exergy. The payback period of system is estimated about 3.5 years.

Investigation into Na and Cs activity coefficients in high salt solutions to support Cs removal in Hanford tank waste

Abstract The treatment of Hanford tank waste is one of the most technically challenging environmental cleanup activities for the U.S. Department of Energy to date. To expedite the processing of liquid waste stored in underground tanks in southeastern Washington state, it is necessary to remove the significant dose contributor, 137Cs. Toward this effort, ion exchange with crystalline silicotitanate (CST) has been employed as part of the Tank Side Cesium Removal system. The model used to predict Cs exchange onto CST was developed using activity coefficients calculated from the Bromley equation. A series of batch contact tests that varied in [Na] were conducted to look at the impact of Na concentration on Cs distribution. Experimental distribution ratios (K d) were compared to the distribution ratios predicted using three different activity coefficient models: (1) commercially available HSC software, (2) the Bromley equation, and (3) a simplified approach adapted from Marcos-Arroyo et al. Ultimately, the Bromley method underpredicted the effect of ionic strength on the Na activity coefficient (γ Na+), HSC overestimated the impact of ionic strength on the expected performance due to the Cs activity coefficient (γ Cs+), but the simplified approach predicted the experimental K d values quite well in a binary matrix. Expansion of this approach in complex matrices is necessary for application to Hanford tank waste.

Development of Fuel Production Facility Using Waste Plastic as Feedstock

The raising worldwide issue of plastic waste gathering has driven the investigation of imaginative and supportable arrangements. Among these arrangements, the development and evaluation of fuel offices that change squander plastic into significant energy assets have acquired noticeable quality. This far reaching survey dives into the present status of information and progressions in this field, enveloping plausibility studies, arranging and preprocessing strategies, transformation innovation determination, facility plan, and performance assessment. By reusing waste plastic as a feedstock for fuel production, these undertakings present a double an open door to oversee plastic waste while at the same time tending to energy requests. Through a blend of examination discoveries, this research highlights the significance of informed direction and streamlining systems chasing building and really working this production of fuel. Besides, the study highlighted cooperative exploration, strategy support, mechanical development, and worldwide collaboration as crucial drivers for accomplishing fruitful waste plastic-to-fuel change, adding to more reasonable waste administration rehearses and a progress to a roundabout economy. Materials used include; plastic waste, sorting equipment, reactor vessel, gas burner, condenser, analytical equipment, and storage tank. The reactor was placed on the gas burner and connected to the condenser through the holes pipe and the fuel collect was placed under the condenser outlet to receive our end product. Before running the test, the weight of the plastic waste was measured. the estimated regression coefficients alongside their standard errors, t-values, and p-values. The coefficients address the connection between the independent variables and the dependent variable in the regression model. The intercept term in the relapse model shows the anticipated worth of the reliant variable (fuel production) when all autonomous factors are zero. In Table 4.4, the intercept coefficient was assessed as 8.000 with a standard error of 5.873. However, the fact that the coefficient does not have a statistically significant value (t = 1.363, p = 0.264) suggests that the intercept value may not have a significant effect on predicting fuel production.

Utilization of Septic Tank Waste to Enhancement the Growth of Spinach in Various Media

Septic tank waste can be used as a new alternative to be used as fertilizer because human excrement contains the availability of nutrients needed by plants. The research aimed to know the effect of liquid organic fertilizers dose, and plant media type of both to increase the growth and the production of plant spinach. The experimental design used was Block Randomized Design factorial with 9 treatments and 3 replicates. The first factor consists of 3 doses of fermented septic tank waste of human feces. Namely doses of 0 mL/plant (K1), 0,4 mL/plant (K2), 0,6 mL/plant (K3). The second factor is the planting medium consisting of 3 kinds of land or control (M0), land + husk charcoal (M1), land + Manure (M2). The observed variables include the number of leaves, plant height, root length, fresh weight of plant, root fresh weight, dry weight, root dry weight of the plant. The results showed that the fermented septic tank waste 0,6 mL (K3) influential real against the number of leaves. Granting planting media differ very markedly against all variable observations i.e. high number of plants, leaves, root length, fresh weight of plant, root fresh weight, dry weight, root dry weight of the plant. All variables are not found the existence of an interaction between fermented septic tank waste with the media.

The evaluation of aluminum and iron metal oxide settling behaviors for Hanford insoluble solids waste preprocessing

AbstractThe Hanford site is currently one of the largest and most expensive cleanup sites for hazardous, radioactive waste. Over 20% of the waste found at the Hanford site is in the form of a high activity sludge. The insoluble solids in the sludge will need to be concentrated prior to vitrification in the high‐level waste (HLW) melter. This will minimize the amount of liquid that will be evaporated during the melting process and expedite the melter processing rate. One proposed option for concentrating the insoluble solids is gravity settling in the storage tanks. Metal oxide compounds containing aluminum and iron make up the majority of the insoluble solids in the sludge, therefore understanding the behavior of these compounds in various tank waste matrices can facilitate sludge pretreatment options. A study of non‐radioactive slurry solutions containing Al(OH)3 (gibbsite), AlO(OH) (boehmite), and Fe2O3 (iron (III) oxide) was conducted to determine the time dependent interface behavior and settling rates of these compounds. Variations in solids loading and sodium concentration were evaluated to represent waste processing conditions and the results of these settling studies were compared with prior tank waste settling tests. Information gathered from these studies can be used to inform future decisions on sludge treatment processes of the insoluble solids processed at the Hanford site.

Modulating Anion Nanotraps via Halogenation for High-Efficiency 99TcO4-/ReO4- Removal under Wide-Ranging pH Conditions.

Efficient and sustainable methods for 99TcO4- removal from acidic nuclear waste streams, contaminated water, and highly alkaline tank wastes are highly sought after. Herein, we demonstrate that ionic covalent organic polymers (iCOPs) possessing imidazolium-N+ nanotraps allow the selective adsorption of 99TcO4- under wide-ranging pH conditions. In particular, we show that the binding affinity of the cationic nanotraps toward 99TcO4- can be modulated by tuning the local environment around the nanotraps through a halogenation strategy, thereby enabling universal pH 99TcO4- removal. A parent iCOP-1 possessing imidazolium-N+ nanotraps showed fast kinetics (reaching adsorption equilibrium in 1 min), a high adsorption capacity (up to 1434.1 ± 24.6 mg/g), and exceptional selectivity for 99TcO4- and ReO4- (nonradioactive analogue of 99TcO4-) removal in contaminated water. By introducing F groups near the imidazolium-N+ nanotrap sites (iCOP-2), a ReO4- removal efficiency over 58% was achieved in 60 min in 3 M HNO3 solution. Further, introduction of larger Br groups near the imidazolium-N+ binding sites (iCOP-3) imparted a pronounced steric effect, resulting in exceptional adsorption performance for 99TcO4- under super alkaline conditions and from low-activity waste streams at US legacy Hanford nuclear sites. The halogenation strategy reported herein guides the task-specific design of functional adsorbents for 99TcO4- removal and other applications.

Work Accident Reduction Strategies With Job Safety Analysis at the Gum Rosin and Turpentine Factory

The production methods at the Gum Rosin and Turpentine XYZ Factory involve several types of machinery and chemicals that might result in workplace accidents. Although the most recent Job Safety Analysis (JSA) was completed in 2018, various changes in work responsibilities have resulted in complaints from melting station workers in the case of eye irritation caused by turpentine vapor exposure and PGT waste workers as having the possibility of splashes from industrial waste. The purpose of this research is to assemble the most recent JSA document to eliminate potential dangers. This research was organized into four parts. The first stage involves conducting firsthand observations to describe the workers' responsibilities at each station. The second step includes interviewing the HSE staff and supervisors to determine the possible dangers of each operation. The third stage involves consulting with the HSE supervisor to decide on precautions to minimize possible dangers. The fourth stage consists of collecting JSA papers for each station. A total of 18 job descriptions with four categories of hazards were discovered based on the assembled JSA, including physical, chemical, mechanical, and ergonomic risks. Workplace safety recommendations here include the placement of safety signs, the installation of guardrails for waste tanks, and the application of personal protective equipment.

Effect of Na Concentration on Cs Distribution with Crystalline Silicotitanate in Tank Waste Simulants

Crystalline silicotitanate (CST) ion exchange media is currently utilized in the tank side cesium removal (TSCR) system on the Hanford site to remove Cs-137 from the tank waste supernate. As the main dose contributor to the liquid supernate in Hanford tank waste, it is necessary to remove the Cs-137 to expedite low activity waste processing and immobilization. Ongoing batch contact experiments with CST have been done to tease out the impact of group II metals, anions, potassium, and temperature on Cs removal to better understand bounding conditions for operations as well as aid in development of a wholesome isotherm model to predict Cs behavior in the tank waste. This paper discusses the impact of Na concentration on Cs exchange and provides insight into the challenges associated with activity coefficient estimations for modeling Cs distribution in tank waste matrices.