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A pathway analysis computer code called RESRAD has been developed for implementing US Department of Energy Residual Radioactive Material Guidelines. Hydrogeological, meteorological, geochemical, geometrical (size, area, depth), and material-related (soil, concrete) parameters are used in the RESRAD code. This handbook discusses parameter definition...
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... of its high degree of aggregation (i.e., small total porosity), concrete has, in general, a higher dry density than soil. Typical values of dry density in different types of soils and in concrete are shown in Table 2.1. Dry density depends on the structure of the soil matrix (or its degree of compaction or looseness) and on the soil matrix's swelling/shrinkage characteristics. ...
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... use Table 2.1 to estimate dry bulk density (or any other soil properties discussed in this handbook), the user needs to know the soil texture type. The common method used in the field to classify a soil is the "feel" method (Brady 1984). ...
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... standard methods used on Formerly Utilized Sites Remedial Action Program (FUSRAP) sites for determining the particle density and the dry density in soil materials are those prepared by the American Society of Testing Materials (ASTM 1992a-o) and the U.S. Department of the Army (DOA 1970), as listed in Table 2.2. A general discussion on these measurement methodologies is also presented in Blake and Hartge (1986a,b). ...
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... the type of soil is known, then Table 2.1 can be used for a slightly more accurate determination of the input data values for dry density. If no information about the type of soils is available, however, then the values for dry density should be experimentally determined by using one of the methods described in Section 2.2.2. ...
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... 32.12 provides a method of estimating the distribution coefficient from the plant-soil concentration ratio, especially when experimental or literature data are not available. Table 32.1 lists the geometric mean values of Kd obtained from the literature or predicted by using concentration ratios (Sheppard and Thibault 1990). ...
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The concentration and spatial distribution of the gamma ray emitting ²³⁸U, ²³²Th, ⁴⁰K and ¹³⁷Cs radionuclides in dumpsite soils in Agbara were analyzed with the aim of evaluating the radiation hazards and excessive lifetime cancer risk using well calibrated HPGe γ-ray spectrometry technique. The ranges of activity concentrations of ²³⁸U, ²³²Th, ⁴⁰K...
Residual radioactive material guidelines for uranium in soil were derived for the former Baker Brothers, Inc., site in Toledo, Ohio. This site has been identified for remedial action under the U.S. Department of Energy`s (DOE`s) Formerly Utilized Sites Remedial Action Program (FUSRAP). Single-nuclide and total-uranium guidelines were derived on the...
This report provides radiation dose modeling analysis supporting the technical derivation of the authorized limits for selected portions of the Hanford Reach National Monument (HRNM). The RESRAD (Yu et al. 2001) computer program was used as the calculational model. The goal of this effort was to produce authorized limits, in units of pCi/g in soil,...
Citations
... It uses a temperaturedependent formulation (Rimstidt et al., 2012) calculated assuming that a 1 cm-thick layer of 250 μm diameter olivine spherical grains is in contact with porewater at a pH of 7.2. This layer was considered to have a porosity of 0.50, typical of coastal sandy sediments (Yu et al., 1993). ...
The Paris Agreement plans for “net‐zero” carbon dioxide (CO2) emissions during the second half of the 21st century. However, reducing emissions from some sectors is challenging, and “net‐zero” permits carbon dioxide removal (CDR) activities. One CDR scheme is ocean alkalinity enhancement (OAE), which proposes dissolving basic minerals into seawater to increase its buffering capacity for CO2. While modeling studies have often investigated OAE at basin or global scale, some proposals focus on readily accessible coastal shelves, with TA added through the dissolution of seafloor olivine sands. Critically, by settling and dissolving sands on shallow seafloors, this retains the added TA in near‐surface waters in direct contact with atmospheric CO2. To investigate this, we add dissolved TA at a rate of ∼29 Teq y⁻¹ to the global shelves (<100m) of an Earth system model (UKESM1) running a high emissions scenario. As UKESM1 is fully coupled, wider effects of OAE‐mediated increase in ocean CO2 uptake –e.g. atmospheric xCO2, air temperature and marine pH– are fully quantified. Applying OAE from 2020 to 2100 decreases atmospheric xCO2 ∼10 ppm, and increases air‐to‐sea CO2 uptake ∼8%. In‐line with other studies, CO2 uptake per unit of TA added occurs at a rate of ∼0.8 mol C (mol TA)⁻¹. Significantly for monitoring, advection of added TA results in ∼50% of CO2 uptake occurring remotely from OAE operations, and the model also exhibits noticeable land carbon reservoir changes. While practical uncertainties and model representation caveats remain, this analysis estimates the effectiveness of this specific OAE scheme to assist with net‐zero planning.
... The radon pathway (water-independent) is a pathway whereby radon nuclides emit their powerful gamma radiation, which adds to the exposure burden of miners. Soil particles could be swallowed accidentally or not accidentally together with water, dust, or food, and when they contain radionuclides, it adds to the exposure burden of a miner (35). ...
... However, RESRAD offsite code allows users to specify the features of their site and to predict the dose received by an individual at any time up to 1, 000 years. It uses more than 150 variables alongside ICRP-38 radionuclide database" [17]. ...
Anthropogenic activities around a fertilizer company can cause elevation in the concentration of naturally-occurring radioactive materials (NORMs) within surrounding soils, as a result of effluent discharge or heaping of rocks used as raw materials. The aim of this study was to evaluate the human risk associated with exposure to NORMs in soils from communities around Indorama Fertilizer Company Eleme, Port-Harcourt, Rivers State, Nigeria. A sodium-iodide doped with thallium [NaI(TI)] detector was used to measure activity concentrations of these NORMs in 22 soil samples within the study area. The residual radioactivity (RESRAD) offsite modeling program(version 4.0) was then used to estimate the radiation doses and the cancer morbidity risk of uranium-238 (238U), thorium-232 (232Th) and potassium-40 (40K) for hypothetical resident farmer scenario. According to the RESRAD prediction, the maximum total effective dose equivalent (TEDE) during 100 years was found to be 2.82 x 10-5 mSvy-1 at year 12, while the maximum total excess cancer morbidity risk for all the pathways was 3.52E-08 at year 6. Therefore, results obtained from the RESRAD-OFFSITE code in this study has shown that the health risk from effluent discharge within the study area is within acceptable levels according to international standards.
... The porosity and specific surface area (SSA) as shown in table, the large SSA explains the removal of phosphate from aqueous solution. Also the porosity is almost high (0.6) according to the range of porosity values for clay (0.4-0.7) [16]. This explains the efficiency of bentonite for phosphate removal. ...
The investigation of the adsorption potential of the Jordanian calcinated bentonite to remove phosphate ions from aqueous solutions whether they are synthetic or actual samples was studied in this article, The temperatures for calcination ranged from (100°C-900°C). The effectiveness of calcining bentonite's ability to remove phosphate ions was investigated under various conditions, including initial concentration of phosphate ions, calcinations, temperature, particle size, pH levels, adsor-bent dose, and contact time. Using pseudo-first-order, pseudo-second-order rates and intraparticle diffusion models the kinetic studies were carried out. The R 2 values indicated that pseudo-second-order rather than pseudo-first-order provided a better fit for the phosphate transport. The activation energy for the removal for both synthetic and actual materials was computed, and it was found to be 8.93 and 12.120 kJ/mol, respectively, this shows that physisorption may have happened. The rate of phosphate ion uptake was also investigated using intraparticle diffusion model at different variables (temperature, particle size, agitation, and pH values), and both particle diffusion (D p) and film diffusion (D f) coefficients were predicted, with the results indicating that film diffusion (D f) is the rate determining step.
... The capillary pressure under a complete saturation assumption has a uniform value of 1 kN/m 2 for all soil types [17]. As for the permeability coefficients of the selected soil types, several literature sources are applied [18][19][20][21]. The information regarding rain intensity is gathered from the previous study conducted by Lundström et al., as presented in Table 2 [1]. ...
In this work, a previously published model for the water up take of stormwater in sponge-like porous bodies by the group is further developed. This is done by investigating the highest-performing model and considering the water uptake from the surroundings of a pond and rain-infiltrated soil. This implies that water uptake from impermeable to partially permeable surfaces is examined. Hence, the following cases are considered: (1) impervious bottom surface and no precipitation, (2) impervious bottom surface with precipitation, (3) permeable soil with no precipitation, and (4) permeable soil with precipitation. A mathematical model covering all these cases is presented, where the governing equations are the mass conservation and Darcy’s law together with an assumption of a sharp wetting front being a first-order approximation of the complete Richard’s equation. Results for the water uptake height, pond depth, and wetting front are computed numerically and plotted against time. Analytical solutions are also presented in certain cases, and critical values are obtained. The parametric study includes variations in the ratio of the model- to the surrounding ground surface area, initial pond depth, precipitation, and soil characteristics. To exemplify, the time it takes to absorb the water from the pond after a precipitation period is presented. The results are related to the Swedish rainfall data of 1 h duration with a return period of 10 years. When evaluating efficiency, the focus is on the absorption time. Results vary considerably, demonstrating a general trend that with soil infiltration, the water absorption rate is higher. For most cases, the considered water amount is absorbed completely, although depending on the parameters and conditions. These results serve to optimize the model for each of the cases. The main focus of the research lies in the theoretical aspect.
... In nature, the grain size of the sand influences the porosity of the substrate due to its direct dependence on the increasing particle size and its irregular spherical structure, wherein a low sphericity of the particles corresponds to a small particle size, increasing porosity. It has been determined that the normal coefficient for sandy soil is around 0.25-0.5; it can be assumed that the smallest possible particles were utilized for bioconsolidation (Yu et al., 1993). ...
Microbially induced calcite precipitation (MICP) is an efficient and eco-friendly technique that has attracted significant interest for resolving various problems in the soil (erosion, improving structural integrity and water retention, etc.), remediation of heavy metals, production of self-healing concrete or restoration of different concrete structures. The success of most common MICP methods depends on microorganisms degrading urea which leads to the formation of CaCO3 crystals. While Sporosarcina pasteurii is a well-known microorganism for MICP, other soil abundant microorganisms, such as Staphylococcus bacteria have not been thoroughly studied for its efficiency in bioconsolidation though MICP is a very important proccess which can ensure soil quality and health. This study aimed to analyze MICP process at the surface level in Sporosarcina pasteurii and a newly screened Staphylococcus sp. H6 bacterium as well as show the possibility of this new microorganism to perform MICP. It was observed that Staphylococcus sp. H6 culture precipitated 157.35 ± 3.3 mM of Ca2+ ions from 200 mM, compared to 176 ± 4.8 mM precipitated by S. pasteurii. The bioconsolidation of sand particles was confirmed by Raman spectroscopy and XRD analysis, which indicated the formation of CaCO3 crystals for both Staphylococcus sp. H6 and S. pasteurii cells. The water-flow test suggested a significant reduction in water permeability in bioconsolidated sand samples for both Staphylococcus sp. H6 and S. pasteurii. Notably, this study provides the first evidence that CaCO3 precipitation occurs on the surface of Staphylococcus and S. pasteurii cells within the initial 15-30 min after exposure to the biocementation solution. Furthermore, Atomic force microscopy (AFM) indicated rapid changes in cell roughness, with bacterial cells becoming completely coated with CaCO3 crystals after 90 min incubation with a biocementation solution. To our knowledge, this is the first time where atomic force microscopy was used to visualize the dynamic of MICP on cell surface.
... Similarly, to assess the uncertainty of soil type representation in the forest HRU, clay and loam soil types were parameterized in two test model runs. Porosity and hydraulic conductivity for these soil types were taken from Yu et al. (1993), Ritzema et al. (1996), and García-Gutiérrez et al. (2018). To assess the uncertainty of forest areal fraction, the percentage area coverage of the forest HRU was set to 50%, 70%, and 90% in three test model runs. ...
... SOM for the meadow and lawn samples were normally distributed and were compared using a t-test. We used a conversion factor of 2 (Pribyl, 2010) to convert from SOM to soil carbon, that is, SOM is 50% carbon, and a literature value for soil density of 1440 kg/ m 3 for sandy loam (Yu et al., 1993). Above-ground dry biomass was estimated for the meadow by counting the hay harvest in bales, weighing a bale, calculating the proportion of water in a bale by oven drying a sample and multiplying up. ...
The biodiversity and climate crises are critical challenges of this century. Wildflower meadows in urban areas could provide important nature‐based solutions, addressing the biodiversity and climate crises jointly and benefitting society in the process. King's College Cambridge (England, UK) established a wildflower meadow over a portion of its iconic Back Lawn in 2019, replacing a fine lawn first laid in 1772.
We used biodiversity surveys, Wilcoxon signed rank and ANOVA models to compare species richness, abundance and composition of plants, spiders, bugs, bats and nematodes supported by the meadow, and remaining lawn, over 3 years. We estimated the climate change impact of meadow vs lawn from maintenance emissions, soil carbon sequestration and reflectance effect. We surveyed members of the university to quantify the societal benefits of, and attitudes towards, increased meadow planting on the collegiate university estate.
In spite of its small size (0.36 ha), the meadow supported approximately three times more plant species, three times more spider and bug species and individuals, and bats were recorded three times more often over the meadow than the remaining lawn. Terrestrial invertebrate biomass was 25 times higher in the meadow compared with the lawn. Fourteen species with conservation designations were recorded on the meadow (six for lawn), alongside meadow specialist species.
Reduced maintenance and fertilising associated with meadow reduced emissions by an estimated 1.36 Mg CO2‐e per hectare per year compared with lawn. Relative reflectance increased by 25%–34% for meadow relative to lawn. Soil carbon stocks did not differ between meadow and lawn.
Respondents thought meadows provided greater aesthetic, educational and mental wellbeing services than lawns. In open responses, lawns were associated with undesirable elitism and social exclusion (most colleges in Cambridge restrict lawn access to senior members of college), and respondents proved overwhelmingly in favour of meadow planting in place of lawn on the collegiate university estate.
This study demonstrates the substantial benefits of small urban meadows for local biodiversity, cultural ecosystem services and climate change mitigation, supplied at lower cost than maintaining conventional lawn.
... Coarse-textured soils (sandy soils) are more prone to high bulk density. Assuming same particle density, sandy soils have smaller porosity values (0.25-0.4) as compared to silt (0.35-0.5) and clayey soils (0.4-0.7) (Yu et al., 1993;Hillel, 2003). Given that bulk density is inversely related to total porosity, we can typically emphasize that coarse-textured soils are generally more dense than fine-textured soils. ...
Soil structure is a key attribute of soil quality and health that significantly impacts water infiltration. Structure can be significantly altered by natural or anthropogenic drivers including soil management practices and can in turn impact soil infiltration. Those changes in soil structure are often complex to quantify and can lead to conflicting impacts on water infiltration into soils. Here, we present a narrative systematic review (SR) of the impacts of soil structure on water infiltration. Based on inclusion and exclusion criteria, as well as defined methods for literature search and data extraction, our systematic review led to a total of 153 papers divided into two sets: experimental (131) and theoretical (22) papers. That implied a significant number of in-situ and field experiments that were conducted to assess the impacts of soil structure on water infiltration under the influence of different land uses and soil practices. Analysis of the metadata extracted from the collected papers revealed significant impacts of soil structure on water infiltration. Those effects were further attributed to land use and management, where we demonstrate the impact of three unique categories: soil amendments, crop management and tillage. Furthermore, significant correlations were established between infiltration rate and soil structural properties, with R² values ranging from 0.51 to 0.80 and for saturated hydraulic conductivity and soil structural properties, with R² values ranging from 0.21 to 0.78. Finally, our review highlighted the significant absence of and the need for theoretical frameworks studying the impacts of soil structure on water infiltration.
... Any estimated porosity values over 60 % were reduced to a value of 60 % as this was deemed to be the realistic upper value of porosity, being the maximum estimated porosity for the samples in this study (Table S5 in SI) and also being towards the upper end of the range of typical porosity of clay-dominated materials (e.g. Yu et al., 1993). ...
... For the upper bound porosity model (Uφ), the porosity was assumed to be 48 % for all samples, which is the median value of the estimated porosities. This was deemed valid because in in line with the expected porosity values for both sand (0.25-0.5) and clay (0.4-0.7) materials (e. g. Yu et al., 1993). The bulk density was subsequently calculated according to the dry density and both the upper and lower bound porosity models, as explained in more detail in section 3.5.3. ...
The management of mine tailings presents a global challenge. Re-mining of tailings to recover remaining metals and other valuable constituents could play a crucial role in reducing the volume of stored tailings. To assess the resource potential of tailings storage facilities, 3D resource models must be constructed. This is not straightforward owing to the heterogeneous nature of tailings. In this case study, modelling of the Davidschacht tailings deposit was performed using universal sequential Gaussian simulation, to account for the strong trends and heterogeneity in chemical distribution. The tonnages of the valuable elements were estimated with reasonable certainty, confirming that relatively few drill holes are required for robust resource estimates of tailings storage facilities. Zinc is the most abundant valuable metal (∼5,170±517 t), followed by Pb (∼2,060±206 t), Cu (∼550±66 t) and In (∼11±1 t), while the toxic elements As and Cd are present in tonnages of ∼8,350±585 t and ∼47±4 t, respectively, with errors given for 95 % confidence levels. Despite the In tonnage being low compared to the other elements, its in situ value is around half that of Cu and Pb, demonstrating the importance of high value by-products for re-mining potential. Although tailings deposits typically have lower grades than primary ore deposits, and the quantities of recoverable valuable elements may be even lower due to current technological limitations, re-mining of TSFs may help to diversify raw materials supply chains and should also be considered for rehabilitation purposes. Geostatistical modelling, particularly universal kriging-based simulation, has been proven to produce robust tonnage estimates of tailings storage facilities and should be adopted in industry to reduce the technical and financial uncertainties associated with re-mining.
