Search

The source of uranium is an important research topic related to the exploration of sandstone-type uranium deposits, and potential uranium sources in deep basins are often overlooked. Black organic-rich shale is a common uranium-bearing rock in deep sedimentary basins. However, relatively few studies have investigated the migration of uranium during hydrocarbon generation in and release from uranium-rich shale. In this study, the uranium-rich shale in the Chang 7 member of the Yanchang Formation of the Upper Triassic in the Ordos Basin was selected to investigate the migration of uranium and other trace elements during the thermal maturation of uranium-rich shale via a semiopen pyrolysis simulation system. The gas and liquid products as well as the solid residue were thoroughly analysed by means of multiple instruments. The results showed that uranium significantly migrated before hydrocarbon generation (Ro < 0.61%), with a leaching rate between 12.1% and 18.8%. The leaching rate of uranium during the hydrocarbon generation stage (0.63% < Ro < 1.35%) was relatively low, ranging from 0 to 7.2%. Cu, Pb, Zn, Mo, and other trace elements also migrated considerably during the early stage of thermal evolution, with leaching rates ranging from 2.9 ~ 11.6%. The yield of low-molecular-weight organic acids (LOAs) was the highest in the early stage of thermal maturity, and the LOA yield exhibited a good correlation with the leaching rates of Cu, Pb, Zn, Co, Mo, etc. The generation of LOAs from source rocks was conducive to the leaching and migration of trace elements. Moreover, according to a statistical analysis of published geochemical data, the total organic carbon (TOC) content, uranium content, and U/TOC ratio in shale decreased significantly with increasing burial depth, indicating that uranium migrated significantly upon kerogen hydrocarbon generation during thermal evolution. Therefore, uranium-rich shale is an important deep uranium source in sedimentary basins. [ABSTRACT FROM AUTHOR]

Humans are exposed to radiation by the emission of radon gas from the soil surrounding them, necessitating the assessment of the radon exhalation levels in soil. The current study measures the radium concentration and radon mass exhalation rate in 34 soil samples obtained from diverse places near the purported uranium reserves in the Sikar districts of Rajasthan state, India. The concentration of radium is measured using the NaI scintillator detector, while the mass exhalation rate of radon is estimated using a smart RnDuo detector. The measured radium content in the soil is between 10.6–47.5 Bq kg−1 with an average value of 21.7 Bq kg−1. With an average value of 20.6 mBq kg−1 h−1, the radon mass exhalation rate ranges from 5.7–74.5 mBq kg−1 h−1. A positive correlation is observed between 226Ra concentration and 222Rn mass exhalation rate. This study shows that the soil of this area is safe in terms of radium content and radon mass exhalation rates. [ABSTRACT FROM AUTHOR]

The permeability of ore is a key factor affecting the leaching effect of uranium ore, and the addition of surfactants can significantly improve the permeability of ore, thereby strengthening uranium ore leaching. This article simulates two infiltration leaching processes, atmospheric heap leaching and pressurized in-situ leaching, and explores the effect of surfactant cetyltrimethylammonium bromide on uranium leaching rate and ore permeability coefficient in both processes. The results showed that in the atmospheric heap leaching test, adding surfactants increased the ore leaching rate by 30.31% during the same 13 day test cycle, and the leaching process was mainly controlled by surface chemical reactions. In the pressurized in-situ leaching test, based on the results of a leaching cycle of 13 days, the average permeability coefficient increased by 72.89% and 64.07% after adding surfactants to the drained and water containing uranium deposits, respectively. In addition, the peak uranium concentration in the leaching solution appeared 2 days earlier, indicating that the addition of surfactants has a significant promoting effect on in-situ leaching of uranium, improving the leaching efficiency of uranium, and can improve the leaching rate of uranium within the same leaching cycle. [ABSTRACT FROM AUTHOR]

Copyright of Uranium Mining & Metallurgy is the property of Uranium Mining & Metallurgy Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The improper disposal of uranium mine tailings and smelting wastewater poses significant environmental hazards, including contamination of water bodies and soil, and potential health risks to humans through the accumulation of uranium in bones and organs. This study examines the removal of hexavalent uranium (U(VI)) from water using biochar derived from agricultural waste enhanced by hydrogen peroxide (H2O2) and magnetization modifications involving the incorporation of Fe3O4 nanoparticles onto the biochar surface. The adsorption capacities were evaluated through batch experiments, and the mechanisms were analyzed using SEM, FT-IR, XPS, and BET surface analysis. These modifications were found to significantly increase the biochar's specific surface area from 17.606 m2/g to 195.62 m2/g and pore volume from 0.037 cm3/g to 0.132 cm3/g, and surface enrichment with oxygen-containing functional groups, particularly carboxyl groups. The inherent adsorption efficiency of biochar for U(VI) is significantly enhanced by these modifications, with the adsorption capacities of H2O2-modified (HBC) and magnetized HBC (MBC) reaching 69.50 mg/g and 77.58 mg/g, respectively. The adsorption mechanisms of BC, HBC, and MBC for U(VI) involve complexation reactions where hydroxyl and carboxyl groups, among other oxygen-containing functional groups on the biochar, interact with uranyl ions. HBC and MBC exhibit enhanced complexation due to higher carboxyl content, leading to improved U(VI) adsorption. Additionally, the presence of iron-containing functional groups on the surface of MBC contributes to electrostatic interactions and facilitates complexation reactions between Fe-O and uranyl ions, enhancing the overall adsorption process. These findings highlight the potential of modified biochar for the removal of U(VI) from water, particularly for the treatment of mine tailings and smelting wastewater, with significant implications for industrial applications in environmental remediation. [ABSTRACT FROM AUTHOR]

The application of In Situ Leaching (ISL) has significantly boosted uranium production in countries like Kazakhstan. Given that hydrodynamic and chemical processes occur underground, mining enterprises worldwide have developed models of reactive transport. However, modeling these complex processes demands considerable computational resources. This issue is particularly significant in the context of numerical analyses of mining processes or when modeling production scenarios in uranium mining by the ISL technique, given that a substantial portion of computational resources is allocated to solving the hydraulic head equation. This work aims to explore the applicability of PINNs to accelerate hydrodynamic simulations of the ISL process. The solution of the Poisson equation is accelerated by generating an initial approximation for the iterative method through the application of the Inverse Distance Weighting (IDW) interpolation and PINNs. The impact of various factors, including the computational grid and the spacing between wells, on both the accuracy and efficiency of initial approximation and the overall solution of the elliptic equation are explored. Employing the hydraulic head distribution obtained through PINNs as the initial approximation led to a significant reduction in computation time and a decrease in the number of iterations by a factor of 2.8 to 7.10. [ABSTRACT FROM AUTHOR]

Sandstone-type uranium deposits hold significant value and promise within China's uranium resource portfolio, with the majority of these deposits found at the junctions of basins and mountains within Mesozoic and Cenozoic basins. The Kamust uranium mining area, located in the eastern part of the Junggar Basin, represents a significant recent discovery. Prior research on this deposit has been confined to two-dimensional analyses, which pose limitations for a comprehensive understanding of the deposit's three-dimensional characteristics. To address the issue of uranium resource reserve expansion, this study employs 3D geological modeling and visualization techniques, guided by uranium deposit models and mineral prediction methods. First, a 3D model database of the Kamust uranium deposit was constructed, comprising drill holes, uranium ore bodies, ore-controlling structures, interlayer oxidation zones, and provenance areas. This model enables a transparent and visual representation of the spatial distribution of favorable mineralization horizons, structures, stratigraphy, and other predictive elements in the mining area. Second, based on the three-dimensional geological model, a mineral prediction model was established by summarizing the regional mineralization mechanisms, ore-controlling factors, and exploration indicators. Combined with big-data technology, this approach facilitated the quantitative analysis and extraction of ore-controlling factors, providing data support for the three-dimensional quantitative prediction of deep mineralization in the Kamust uranium deposit. Finally, using three-dimensional weights of evidence and three-dimensional information-quantity methods, comprehensive information analysis and quantitative prediction of deep mineralization were conducted. One prospective area was quantitatively delineated, located east of the Kalasay monocline, which has been well-validated in geological understanding. The research indicates that the area east of the Kalasay monocline in the Kamust mining district has significant exploration potential. [ABSTRACT FROM AUTHOR]

This article explores the collection and study of Australian mining songs, specifically those related to gold and coal mining. The author notes a lack of documentation on industrial folk songs and conducted field collecting trips to coal mining towns to gather songs and stories. The article discusses the role of songs during strikes and demonstrations, as well as the changing opportunities for collecting songs through online resources. It also examines the themes and perspectives found in mining songs, including excitement, practicality, despondency, and grievances. The article highlights the increase in literacy among coal mining workers and the circulation of songs through printed materials. It questions whether modern-day miners create songs and mentions the presence of anti-mining songs. Resources for further exploration of Australian mining folklore are provided. [Extracted from the article]

Purpose: The radionuclides pollution base on MMs (metals and metalloids) near uranium mines has been drawing broad attention, but the extent of their impact on soil and human health is still unclear. Therefore, the aim of this study was to investigate the distribution and health risk assessments of 238U, 226Ra, 232Th and 40 K base on MMs (Cr, Ni, Cu, Zn, As, Cd, and Pb) in different surface soils near an uranium mine. Materials and methods: Surface soil samples were extracted from 35 representative sites near the Lefu uranium mine. Radionuclides and MMs were measured using high-purity germanium (HPGe) N-type coaxial detector and inductively coupled plasma mass spectrometer, respectively. Pollution status was evaluated using DR, Raeq, AEDE, Hext, and ELCR for radionuclides and Pi, Igeo, RI and health risk index for MMs. Their correlation was analyzed through Pearson/Spearman correlation analysis. Results and discussion: The average activity concentration of 238U, 226Ra, 232Th, and 40 K are 504, 1227, 118, and 769 Bq·kg−1 respectively and the average concentration of Cr, Ni, Cu, Zn, As, Cd, and Pb are 200, 33.9, 41.3, 132, 18.4, 0.26, and 78.7 mg·kg−1, respectively. Values of DR, Raeq, AEDE, Hext, and ELCR all exceed the world average to varying degrees and values of Pi, Igeo, RI and the health risk index are within the acceptable ranges. Correlation analyses showed that 238U, 226Ra, 232Th and Pb are strongly correlated (correlation coefficient > 0.6) with each other. Conclusions: On the basis of the obtained values, it can be concluded that generally higher radionuclides and MMs were distributed near the Lefu uranium. There are potential health risks associated with the elevated radioactivity. The overall situation of MMs is controllable, however, particular attention is warranted for Cr and Cd, as they approach values-at-risk. The strong correlations between 238U, 226Ra, 232Th and Pb imply a uniform pollution level or a possible shared source. [ABSTRACT FROM AUTHOR]

In order to explore the effect of well spacing on the uranium leaching efficiency in acid in-situ leaching, taking the Bayan Ula mining area as an example, and using the finite element method to establish a numerical model for acid in-situ leaching uranium mining, and discuss the coverage and flow rate of the leaching solution. Through the comparison and analysis of 26 schemes, the influence of different well spacing on uranium leaching was discussed from three aspects; well site cost, uranium leaching cycle, and leaching dead angle. The results show that; 1) The fixed cost of the mining area varies with the well. 2) The characteristic flow velocity in the mining area decreases with the increase of the well spacing, and the relative uranium leaching period increases with the increase of the well spacing; 3) With the increase of the well spacing, the volume of the leaching dead angle increases approximately exponentially. Comprehensive consideration, under the simulation conditions in this paper, it is considered that 26 meters to 30 meters is the optimal well spacing for uranium leaching. The results can provide a reference for the reasonable layout of subsequent ground leaching process hoes in this mine area. [ABSTRACT FROM AUTHOR]

We developed a spatiotemporal mapping approach utilizing multiple techniques for distinguishing and mapping known reclaimed mine sites from "unreclaimed" mine sites in a historic uranium mining district along the South Texas Coastal Plains. Lidar laser scanning penetrates the vegetation canopy to expose anthropogenic modifications to the landscape. The Lidar analysis (bare earth elevation surface, slope, topographic contours, topographic textures, and overland-flow hydrography) revealed mine features. Visual interpretation of Landsat imagery and time-series analysis augmented the Lidar analysis revealing the temporal life cycle of mining. The combination of bare earth texture with time-lapse and time-series analyses revealed areas of disturbance for reclaimed mines. The spatiotemporal mapping approach proved to be most useful in identifying and characterizing the known mine pit and pile features, reclamation status, and areas of disturbance due to mining. Two mine waste volume estimation methods resulted in a 21% difference indicating that although the approach helps to map mine features and areas of mining disturbance for the purposes of mine land inventory, additional information is needed to improve the estimation of buried mine waste at reclaimed mine sites. [ABSTRACT FROM AUTHOR]

Brazilian mining ventures aged 30 years or older were studied, revealing historical oversights in environmental planning that have caused substantial environmental liabilities during active mining and decommissioning. Electrical resistivity tomography surveys were conducted in a decommissioning uranium mine in southeast Brazil. The results provided valuable insights into local hydrogeological dynamics, revealing the flow of acid mine drainage in two distinct systems: the porous waste rock pile and the fractured underlying crystalline basement. Geo-electrical sections displayed conductive anomalies indicating hydraulic connectivity between the waste rock pile and the underlying fractured aquifer through crystalline basement fractures. This connection was substantiated by sub-vertical zones of low electrical resistivity interpreted as groundwater influx from the porous system to the fractured aquifer. Consequently, the waste rock pile acted as a localized recharge zone for the regional aquifer, facilitating chemical exchanges between the two systems. Furthermore, the study successfully differentiated less impacted saturated zones (resistivity ≈80 Ω·m) from those associated with acid mine drainage (< 40 Ω·m). Preliminary investigations identified a complex fracture network in the study area, comprising two main fault systems with preferential NE and NW orientations, nearly orthogonal to each other. This fracture network demonstrated continuity, playing a fundamental role in sustaining flow within the local and regional drainage network. [ABSTRACT FROM AUTHOR]

Based on scientific research, it appears that for investments in complex energy-mining infrastructures (including the SMR Doicești-Dâmbovița), attention must be paid to the groups of variables belonging to weak points and threats. The main objective of the article is to combine the sub-strategies of the complex energy-mining infrastructures for protection, safety and security, respectively to obtain the appreciation of the level of positive situation on the scale of the coefficients of importance of the components of the researched complex. The approach in relation to the main objective also gives rise to the formulation of three secondary objectives, as follows: a) identification of probabilities and degree of risk assessment regarding protection, safety and security in complex energy-mining infrastructures and characterization of the consequences in the field; b) the application of the SWOT analysis and the TOPSIS Method for the researched objective, emphasizing the characteristics located between appropriate weights; c) highlighting the strategic values of the sub-strategies in relation to nuclear protection, safety and security, showing the decision-makers whether the investment in the energy-mining infrastructure is feasible, reliable and efficient. The paper reports technical protection considerations of the Small Modular Reactors (SMR) system, the list of nuclear hazards/events/incidents drawn up for SMR, technical aspects in the system of underground mining enterprises for the extraction of uranium ore. Also presented are the factors of opportunities, threats, strengths and weaknesses systematized in the SWOT analysis for SMR, the possible algorithm and mathematical models of mining security, the characterization of sub-strategies of protection, safety and nuclear security in relation to the importance coefficients collected for the decision to mount and put into operation the SMR. [ABSTRACT FROM AUTHOR]

The Dashigou deposit is one of the most representative carbonatite-type Mo-REE deposits in the East Qinling metallogenic belt of China, with a molybdenum resource of more than 180 kt and a rare earth resource of 37.8 kt. Recent exploration has revealed a considerable scale of uranium mineralization within this deposit. Therefore, this study conducted detailed mineralogical and EPMA U-Th-Pb chemical dating on the uranium mineralization in the Dashigou deposit. The results indicate that the U-ore body in the Dashigou deposit mainly consists in carbonatite veins, and principally as anhedral, mesh-like uraninite. The mineral assemblage is characterized by uraninite + rutile + bastnasite + parisite or brannerite. The uraninite displays geochemical compositions of high Y and Ce and low Si, Ti, and Mg. The EPMA U-Th-Pb chemical dating is 144 ± 3.1 Ma, representing the Yanshanian uranium mineralization age in the region. The newly discovered uranium mineralization age indicates that the deposit experienced a uranium remobilization event during the Cretaceous and was formed in an intracontinental orogenic and extensional environment post-collision orogeny. [ABSTRACT FROM AUTHOR]

Hope and Trauma in a Poisoned Land was a community engaged regional art exhibition that began as a mixed-method research project. The original purpose was to give voice to the stories of indigenous people living in uranium-contaminated regions of the Navajo Nation. It quickly expanded into a social practice art project, allowing for collaboration between individuals, artists, community members, and several different institutions. Participating artists attended a 4-day informational and interactive workshop about the uranium mining legacy, so that they fully understood contamination issues; the goal was for them to create art from an informed place. The investigators examined the psychological impact of the workshop and the exhibition on the artists as well as the community at large. We found that the greater the emotional impact on the artist, the greater their absorption while making the art and the greater their artwork creativity, as rated by objective evaluators. Community attendees reported increased knowledge about the issue, as well as feeling inspired to take action. Through engaging a community advisory council and artists and patrons on an intellectual, aesthetic, emotional, and compassionate level, we documented how this social practice art exhibition had an impact on our community. [ABSTRACT FROM AUTHOR]

Sandstone-type deposits have emerged as the primary uranium deposits being mined in China, utilizing in-situ leaching technology. However, the leaching of uranium resources within sandstone formations faces significant constraints due to their extremely low permeability, accounting for approximately seventy percent of the total. This paper aims to present recent advancements in the field in enhancing seepage-leaching mass-transfer properties in in-situ leaching of uranium from low-permeability sandstone. We will provide an overview of the main factors influencing the in-situ leaching process in low-permeability ore layers, discussing the technical characteristics of applicable methods designed to enhance permeability in low-permeability uranium-bearing sandstone based on the existing research. Additionally, we will also explore the suitability of various approaches from other fields in the in-situ leaching of uranium process. Finally, we will outline the prospects regarding process methodologies, leaching agents, and enhancing permeability methods. [ABSTRACT FROM AUTHOR]

This article discusses the mineral specimen known as samsonite, which is highly valued by collectors. Samsonite is a rare mineral composed of silver, manganese, and sulfur, and it was discovered in the St. Andreasberg mining district in Germany. The article provides information about the physical characteristics of samsonite and its historical significance. It also describes the acquisition process of a samsonite specimen by the Smithsonian Institution. Overall, the article offers valuable insights into the world of mineral collecting and the importance of samsonite as a prized mineral specimen. [Extracted from the article]

A log data analysis plays an important role in the uranium mining process. Automating this analysis using machine learning methods improves the results and reduces the influence of the human factor. In particular, the identification of reservoir oxidation zones (ROZs) using machine learning allows a more accurate determination of ore reserves, and correct lithological classification allows the optimization of the mining process. However, training and tuning machine learning models requires labeled datasets, which are hardly available for uranium deposits. In addition, in problems of interpreting logging data using machine learning, data preprocessing is of great importance, in other words, a transformation of the original dataset that allows improving the classification or prediction result. This paper describes a uranium well log (UWL) dataset generated with the employment of floating data windows and designed to solve the problems of identifying ROZ and lithological classification (LC) on sandstone-type uranium deposits. Comparative results of the ways of solving these problems using classical machine learning methods and ensembles of machine learning algorithms are presented. It has been shown that an increase in the size of the floating data window can improve the quality of ROZ classification by 7–9% and LC by 6–12%. As a result, the best-quality indicators for solving these problems were obtained, f1_score_macro = 0.744 (ROZ) and accuracy = 0.694 (LC), using the light gradient boosting machine and extreme gradient boosting, respectively. [ABSTRACT FROM AUTHOR]

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of World Nuclear Geoscience is the property of World Nuclear Geoscience Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sandstone uranium deposits in the Kelulun Depression are the first commercially viable uranium deposits discovered in the Hailar Basin and the ore-bearing strata corresponding to the Lower Cretaceous Yimin Formation. However, the source of sedimentary matter, uranium source conditions, and uranium mineralization processes in the region have not been characterized. Accordingly, we analyzed the lithology, whole-rock geochemistry, zircon U-Pb ages, and trace elements of the Yimin Formation sandstones. The Yimin Formation sandstones were primarily composed of detrital grains with low compositional maturity. A geochemical analysis indicated that the parent rocks are felsic igneous rocks formed at an active continental margin with a moderately high degree of weathering. The detrital zircon U-Pb ages of the Yimin Formation 215–287 Ma with a peak at 230–260 Ma. Based on chronological, geochemical, and lithological data, we conclude that the Yimin Formation matter is derived from the Adunchulu Uplift on the western side of the Kelulun Depression and its parent rocks are Triassic granites. The Adunchulu uplift since the late Early Cretaceous and weathering and denudation of its uranium-rich granites provided ample matter and uranium. Therefore, the Kelulun Depression is a promising area for the exploration of sandstone uranium deposits. [ABSTRACT FROM AUTHOR]

A radiological assessment of inland freshwater fishes of wetland haor zones, near a uranium mine and Rooppur Nuclear Power Plant (RNPP) areas, was performed. Gamma spectrometric analysis showed the accumulation of 226Ra, 228Ra, and 40K in all studied fishes, with varying degree levels of concentrations. The average radioactivity levels of 226Ra, 228Ra and 40K in haor fish samples ranged from 2.76 ± 1.51 to 22.02 ± 3.81 Bq kg−1, 1.78 ± 0.69 to 21.53 ± 1.40 Bq kg−1 and 405.51 ± 22.04 to 749.80 ± 42.65 Bq kg−1, respectively. Conversely, the respective values for Bata fish samples of Rooppur Nuclear power plant sites varied from 2.66 ± 0.80 to 6.62 ± 0.81 Bq kg−1, 2.31 ± 0.62 to 5.18 ± 49.81 Bq kg−1 and 342.00 ± 4.98 to 461.45 ± 18.00 Bq kg−1, respectively. Activity levels of Taki fish (Channa punctatus) from haors zones were almost 3–4 times higher than the Meni fish (Nundus nundus) of the same locations and Bata fish (Labeo bata) of the RNPP site. The general public may attain doses of 244.54 µSv from the consumption of haor fish and 84.02 µSv from the fish of the RNPP sites yearly. The chance of an increase in cancer risk from intake of haor fish was higher than the ICRP values of 2.9 × 10−4. Univariate statistics showed that 226Ra and 228Ra radionuclides do not normally distribute, whereas 40K is normally distributed in the studied fish species. Multivariate statistical analysis demonstrated that the radioactivity and estimated radiological parameters are strongly positively correlated with 226Ra and 228Ra, and also positively correlated with 40K. Hence, it indicated that the contents in the freshwater fish species are usually controlled and influenced by similar geogenic sources and occur together. It is presumed that the radiological risk is mostly associated with and dominated by the uranium and thorium series and non-series 40K radionuclides in the freshwater fish species. [ABSTRACT FROM AUTHOR]

Radon (Rn) and helium (He) gases from uranium decay form distinct anomalies related to buried uranium deposits. In order to trace the geochemical anomalous sources from the volcanic-related uranium deposits in deeply buried areas, systematical Rn contents and He isotope ratios were analyzed from the Daguanchang uranium deposit. The soil gas Rn concentrations above the deep uranium are ten times higher than those in barren areas, indicating that instantaneous Rn content measurements can be used to detect deeply buried uranium. The helium isotope ratios (3He/4He) of the unmineralized samples from the mineralized drill hole (ZK1) are relatively lower and uniform compared to those of the samples from no-mineral drill hole (ZK2). However, the Th and U contents of the drill core samples from ZK1 are slightly lower than those of the samples from ZK2, indicating that the lower 3He/4He ratios in ZK1 are most likely due to the addition of 4He from underlying uranium intervals. The differences in the instantaneous Rn contents are consistent with the variations in the He isotope ratios of the drill core samples. These results demonstrate that soil gas Rn and 3He/4He ratios are useful tracers and can indicate the existence of deeply buried volcanic-related hydrothermal uranium ores. [ABSTRACT FROM AUTHOR]

An assessment was carried out at Nuclear Technology Development Centre to evaluate the capacity of the plant species Epipremnum pinnatum to uptake, translocate and accumulate Th and U. The experiments were conducted under controlled conditions in a greenhouse, using cultivation in soil from uranium mine and cultivation in nutrient solution (hydroponic technique) using standards of the elements of interest. The plant species was analysed by Neutron Activation , k0 standardization method. The ANOVA test, R software and Tukey's correction were applied, the results of which showed that the candidate biomonitor plant presented good Th and U uptake in both experiments, indicating a preference for accumulate in the roots. [ABSTRACT FROM AUTHOR]

In situ elemental content and 207Pb/206Pb values in three rough fracture coatings within drill cores from the McArthur River unconformity-related uranium deposit, Athabasca Basin, Canada, were measured using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) image mapping. Fracture-coating samples were located proximal and distal to the ore deposit. Samples required minimal preparation in this method, with areas (c. 500 × 500 μ m) targeted in a cell-spaced grid pattern using a 50 μ m spot, spaced 200 μ m on the x-axis with an offset of 100 μ m on the y-axis, to overcome sample surface topography. A 5 s acquisition time was applied to elemental content measurements and a 2 s acquisition time was applied to 207Pb/206Pb measurements. These parameters increased the spatial resolution and analytical sensitivity and minimized the contribution of the host rock underlying the fracture surface to the geochemical signal in comparison to extended acquisition times. In addition, laser ablation temporal profiles allow for the interpretation of the timing of element/isotope migration and fixation on the rough fracture coating. Rasterized maps generated in Iolite™ v.4 demonstrate the chemical distribution of elements and 207Pb/206Pb values on the rough fracture coatings, allowing for the identification of mineral phases hosting pathfinder elements, pathfinder element associations and the generation of bulk in situ or specific mineralogy geochemical values. Bulk in situ values calculated using an integration of the 2D image data and targeting the c. 500 × 500 μ m surface of the fracture coating compared to previous bulk geochemical methods obtained by sampling the fracture coating with a microdrill (i.e. modified aqua regia (HCl: HNO3: H2O) and weak acid leach (2% HNO3)) highlights that in situ analysis greatly improved detection of pathfinder elements on the fracture surface. This study is the first application of in situ LA-ICP-MS for measuring element contents and 207Pb/206Pb values on rough fracture coatings and demonstrates its importance as a new geochemical tool to the mining industry for future mineral exploration. [ABSTRACT FROM AUTHOR]

In this study, we used 16S high-throughput sequencing to investigate the effects of uranium mining on the rhizospheric bacterial communities and functions of three local plant species, namely, Artemisia frigida, Acorus tatarionwii Schott., and Salix oritrepha Schneid. The results showed that uranium mining significantly reduced the diversity of rhizospheric bacteria in the three local plant species, including the Shannon index and Simpson index (P < 0.05). Interestingly, we found that Sphingomonas and Pseudotrichobacter were enriched in the rhizosphere soil of the three local plants from uranium mining areas, indicating their important ecological role. The three plants were enriched in various dominant rhizospheric bacterial populations in the uranium mining area, including Vicinamidobacteriaceae, Nocardioides, and Gaiella, which may be related to the unique microecological environment of the plant rhizosphere. The rhizospheric bacterial community of A. tatarionwii plants from tailings and open-pit mines also showed a certain degree of differentiation, indicating that uranium mining is the main factor driving the differentiation of plant rhizosphere soil communities on the plateau. Functional prediction revealed that rhizospheric bacteria from different plants have developed different functions to cope with stress caused by uranium mining activities, including enhancing the translational antagonist Rof, the translation initiation factor 2B subunit, etc. This study explores for the first time the impact of plateau uranium mining activities on the rhizosphere microecology of local plants, promoting the establishment of effective soil microecological health monitoring indicators, and providing a reference for further soil pollution remediation in plateau uranium mining areas. [ABSTRACT FROM AUTHOR]

Environmental protection and resource reclamation make the extraction of uranium from uranium‐containing wastewater be a key role in the nuclear chemistry and industry. Although previous studies have revealed several effective methods and materials for such use, however, few studies are concerned about the wastewater discharge issues. In fact, the direct discharge of treated wastewater into the environment is still not a green way. Here, an innovative conversion approach is shown, which can simultaneously achieve the uranium extraction and conversion of wastewater to valuable chemical. This concept is implemented by an azobenzene‐pendent covalent organic framework, showing smart trans‐to‐cis photoresponsive properties in both space and electronic structure and consequently, largely enhanced extraction and conversion efficiency under UV irradiation, relative to visible light irradiation. In real wastewater, the material is found to give selective and 100% uranium extraction and H2O2 generation (1872.3 µmol g−1 h−1). The mechanism is due to a unique photocatalysis coupling between the uranium reduction reaction (URR), aiming at uranium recovery or removal, and the water oxidation reaction (WOR), targeting the conversion of wastewater into a valuable chemical of H2O2. [ABSTRACT FROM AUTHOR]

The reaction between the lixiviant and the minerals in the aquifer of In-situ uranium leaching (ISL) will result mineral dissolution and precipitation. ISL will cause changes in the chemical composition of groundwater and the porosity and permeability of aquifer, as well as groundwater pollution. Previous studies lack three-dimension numerical simulation that includes a variety of minerals and considers changes in porosity and permeability properties simultaneously. To solve these problems, a three-dimensional reactive transport model (RTM) which considered minerals, main water components and changes in porosity and permeability properties in Bayanwula mine has been established. The results revealed that: (1) Uranium elements were mainly distributed inside the mining area and had a weak trend of migration to the outside. The strong acidity liquid is mainly in the mining area, and the acidity liquid dissolved the minerals during migrating to the outside of the mining area. The concentration front of major metal cations such as K+, Na+, Ca2+ and Mg2+ is about 150m away from the boundary. (2) The main dissolved minerals include feldspar, pyrite, calcite, sodium montmorillonite and calcium montmorillonite. Calcite is the most soluble mineral and one of the sources of gypsum precipitation. Other minerals will dissolve significantly after calcite is dissolved. (3) ISL will cause changes in porosity and permeability of the mining area. Mineral dissolution raises porosity and permeability near the injection well. Mineral precipitation reduced porosity and permeability near the pumping well, which can plugging the pore throat and affect recovery efficiency negatively. [ABSTRACT FROM AUTHOR]

ABSTRACT Quaternary to Recent sedimentary dolomite in groundwater calcrete and saltmarsh sediments of Lake Way and Lake Maitland, Western Australia, provide new information about the formation of low‐temperature dolomite. Dolomite can form through numerous pathways depending on the depositional and diagenetic environment. Many pathways involve microbial processes and/or the presence of a nucleation substrate which help overcome kinetic barriers preventing precipitation in the laboratory. Petrographic, mineralogical, hydrogeochemical and stable isotopic data in this study reveal the importance of Mg‐clays as nucleation sites for dolomite precipitation in a range of aquifer environments. There is also a close association between authigenic Mg‐clays, dolomite and the potassium–uranyl–vanadate ore mineral carnotite in channel and playa uranium deposits. It is interpreted that evaporation‐driven precipitation of dolomite establishes a positive feedback loop promoting the dissociation of aqueous uranyl–carbonate complexes and concomitant increase in carnotite saturation. Critical to this model is the presence of authigenic Mg‐clays because they facilitate dolomite precipitation and promote carnotite nucleation by concentrating potassium ions on clay surfaces via adsorption. This Mg‐clay–dolomite–carnotite relationship is widespread throughout Western Australian channel and playa uranium deposits and has been observed in similar deposits in Namibia and Botswana. In addition to this economic implication, Mg‐clay mediated nucleation of dolomite potentially has global relevance as a precipitation mechanism for low temperature dolomite in sedimentary deposits where detrital and/or authigenic Mg‐clays are present. Maturation of sedimentary dolomite from disordered high‐calcian dolomite to ordered low‐calcian dolomite occurs very early in the meteoric realm making it resistant to alteration during burial diagenesis. Diagenetic resistance may be further increased by early meteoric silicification related to the degradation of associated Mg‐clays. These findings indicate that Mg‐clay associated sedimentary dolomite has potential to retain a primary isotopic signature indicative of its origin, making it a useful recorder of palaeoenvironmental conditions. [ABSTRACT FROM AUTHOR]

In recent years, there have been important breakthroughs in the exploration for sandstone-hosted uranium (U) deposits in the Louzhuangzi district of the southern Junggar Basin. Between 2020 and 2023, a medium-sized sandstone-hosted uranium deposit production area was identified in the region. Only a few investigations have been conducted at the Louzhuangzi U deposit, including those analyzing its geological–tectonic evolution, basic geological features, hydrogeology, and ore-controlling factors. It is generally believed that uranium mineralization at the Louzhuangzi U deposit is controlled by a redox zone. Organic matter (referred to as OM hereafter) consisting of bitumen and carbonaceous debris is very common in the uranium ores (especially in high-grade ores) at the Louzhuangzi U deposit. However, the characteristics of the OM and its contribution to uranium's mineralization have not been studied in detail. In this study, OM-rich U-ores, altered sandstone, and barren sandstone samples were collected for petrography, mineralogical, micro-spectroscopy, carbon, and sulfur isotope studies. The results of this study show that the distribution of U minerals and metal sulfides (pyrite, sphalerite, etc.) was strictly controlled by bitumen at the Louzhuangzi U deposit. The bitumen may have been formed by hydrocarbon-rich and U-rich ore-forming fluids, which were formed after hydrocarbon generation and expulsion in the underlying Jurassic coal-bearing source rocks. The fluids contained U, Zn, Fe, and other metal elements, which migrated together and then precipitated into the oxidized Toutunhe Formation sandstone through cracking and differentiation processes. Therefore, the results indicate that migrated hydrocarbons were involved in U mineralization, in addition to oxidation–reduction processes, in the Louzhuangzi district, south of the Junggar Basin (China). [ABSTRACT FROM AUTHOR]

This research investigated the natural radioactivity levels of gamma emitters (Uranium-238, Thourium-232, and Potsium-40) and some radiological hazard indices in soil samples obtained from the vicinity of Al-Jibsa Marsh, located in Najaf Governorate. Experiments were conducted using the NaI(Tl) method. The specific activity values of 238U ranged from 14.548 Bq/kg to 266.016 Bq/kg, with an average of 112.332 Bq/kg. For 232Th, the values ranged between 0.812 Bq/kg to 20.720 Bq/kg, with an average of 7.653 Bq/kg. The specific activity values of 40K ranged from 7.975 Bq/kg to 244.992 Bq/kg, with an average of 82.497 Bq/kg. The activity of 235U varied between 0.670 Bq/kg and 12.259 Bq/kg, with an average of 5.177 Bq/kg. Moreover, the average values of some radiological hazard indices such as (Raeq), (Hext), (AD), (ELCR) were 129.628, 0.350, 60.090 nGy/h, and 1.3267x10-3, respectively. When comparing the results of the current study with the global limit according to UNSCEAR, 2008, it is found that the values of uranium-238 in most of the soil samples were high. Therefore, the soil in this area is unsafe and harmful to the people living near this area. [ABSTRACT FROM AUTHOR]

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Artefactos: Revista de Estudios Sobre La Ciencia Y La Tecnologia is the property of Ediciones Universidad de Salamanca and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Uranium occurs naturally in groundwater and surface water. Being a radioactive element, high uranium concentration can cause impact on human health. The health effects associated with consumption of uranium through water includes increased cancer risk and kidney toxicity. In view of this, an attempt was made in the present study to establish the level of radiological and chemical toxicity of uranium. Radiological toxicity was evaluated in terms of lifetime cancer risk and chemical toxicity through hazard quotient. For the said purpose, groundwater samples from the selected villages of the surrounding region of the Manchanabele reservoir, southwest of Bengaluru, were collected. The collected groundwater samples were analysed for Uranium mass concentration using Light emitting diode (LED) fluorimeter and is found to range from 0.88 to 581.47 ppb with a GM of 20.82 ppb. The result reveals that ~ 66% of the samples show concentration of uranium within the safe limit of 30 ppb as set by the World Health Organisation. The radiological risk estimated in terms of lifetime cancer risk is in the range of 0.0028 × 10−3 to 1.85 × 10−3 with a GM of 0.066 × 10−3. The chemical toxicity risk measured as lifetime annual daily dose is found to range from 0.03 to 21.65 μg per kg per d with a GM of 0.77 μg per kg per d. [ABSTRACT FROM AUTHOR]

Exploration in the mining sector results in the accumulation of extensive databases encompassing diverse geochemical datasets. The efficient processing of this multivariate data necessitates the application of advanced Python data analysis tools. Such an approach is essential for the extraction of criteria that will inform and optimize future exploration and mining operations. In this study, we utilize the Python language to explore the database of Aura Energy Company established within the uranium exploration project in the regions of Oued El Foula and Aïn Sder, where a total of 1065 drilling wells have been executed. The uranium deposit in Oued El Foula and Aïn Sder is of a surficial type and results from alteration and erosion of granites. Overall, economic concentrations of uranium are near the surface (with a depth of less than 10 m) and hosted in unconsolidated rock (mainly in colluviums) and igneous rocks (mainly granites). The uranium deposit exhibits an economic association with vanadium and thorium. The granites in the regions of Oued El Foula and Aïn Sder form from the melt at the upper continental crust. In addition, these granites show enrichment in LILE and depletion in HFSE which is a characteristic of alkaline granites resulting from wet melting and evolved melt. [ABSTRACT FROM AUTHOR]

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of uranium and its decay product radon in water are the most important concern in human health. In this paper, efforts have been made to measure and correlate the uranium (Using an LED Fluorimeter) and radon concentrations (Using SMART RnDuo) in the water samples from the Budhakedar region of the Garhwal Himalaya to assess the risk. The concentrations of uranium and radon in the water samples were found to vary between Below Detection Level (BDL) to 1.70 Bq L−1 (with an arithmetic mean of 0.15 Bq L−1) and 0.43 to 1.29 Bq L−1 (with an arithmetic mean of 0.75 Bq L−1) respectively. The annual effective dose to the inhabitants of the study region was also calculated for the different age groups. [ABSTRACT FROM AUTHOR]

Natural elements like uranium and its by-products can cause health problems if they are present in groundwater at excessive concentrations. Some industrial activities are known to elevate uranium concentrations, such as uranium mining, phosphate fertilizer production, nuclear power plants, metal processing, and coal combustion. This study gives information about the uranium concentration in groundwater samples collected from distinct water sources like hand pumps and tube wells from a variety of depths and numerous locations in Yamuna Nagar, Near Shivalik Hills, and the Origin of Saraswati River, India. Uranium concentration was measured using the LED fluorimetry technique. The average value of uranium (13.09 µg L−1) and annual effective dose (2.18 µSv y−1) is found to be within the as reported by WHO (Guidelines for drinking-water quality, World Health Organization, Geneva, 2011) and as reported by AERB (Drinking water specifications in India, Department of Atomic Energy, Mumbai, 2004) recommended safe limits of 30 µg L−1 and 60 µg L−1 respectively. For the evaluation of health risks associated with groundwater, the chemical toxicity risk and radiological risk of uranium in water are also assessed in this study. The activity of natural radionuclides in some locations is found to be high, which might be due to the local geology, hydrology, and type of industries in that region. The current study will benefit both residents and government agencies regarding uranium exposure to drinking water. [ABSTRACT FROM AUTHOR]

The presence of underlying uranium deposits may contaminate the upper soil of a region. We have carried out a detailed investigation of radionuclides (Ra, Th, and K) present in the soil around the reported uranium deposit site in the Sikar district of Rajasthan, India. Measurements are carried out using the state-of-the-art gamma-ray spectroscopy (HPGe detector) technique. The specific activity of 226Ra, 232Th, and 40K are found in the range of 9.5 ± 0.5–50.6 ± 1.0 Bq kg−1, 11.0 ± 0.4–83.2 ± 1.5 Bq kg−1, and 177 ± 13–753 ± 47 Bq kg−1 with the mean values of 17.8 ± 7.5 Bq kg−1, 22.6 ± 13.4 Bq kg−1, and 393 ± 76 Bq kg−1 respectively. The average value of Ra Eq. activity is 80.4 Bq kg−1, below the recommended limit of 370 Bq kg−1. For radiological implications in the study area, the indoor and outdoor absorbed dose rates and age-dependent annual effective dose are estimated, which are also found below their prescribed safe limit values. The mean value of other hazard indices (Hin and Hex) and level indices (Iα and Iγ) are less than unity. Our study shows that the underlying uranium deposits do not contaminate the soil of the studied area and the soil is safe to use for various purposes. [ABSTRACT FROM AUTHOR]

Evaluating groundwater uranium concentration is crucial for assessing the radiological impact on human health due to radionuclide ingestion. This study quantifies uranium concentration in groundwater samples collected from various sources in the Patiala district, Punjab. LED Fluorimeter is employed for direct determination of uranium. Results reveal that 78% of locations have uranium concentration below the WHO limit of 30 µg/L, while 22% exceed the safe limit. However, all samples are below the AERB-recommended 60 µg/L limit. The uranium concentration in the groundwater ranges from 5.59 to 57.53 µg/L, with an average concentration of 24.57 µg/L. The variation in uranium concentration is influenced by factors such as pH and the water source. Radiation dose, cancer risk, and daily intake are calculated, suggesting most samples are safe for drinking, but prolonged consumption in high-uranium areas poses health risks. [ABSTRACT FROM AUTHOR]

The measurements of radon concentrations in drinking water sources in and around the Main Central Thrust (MCT) region in Garhwal Himalaya, India, were carried out using the scintillation detector-based SMART RnDuo technique for radiation protection purposes. Radon values in the analyzed samples were observed between 1.1 and 183.9 Bq L−1 (AM = 19.7 Bq L−1). Radon values in 94% of the samples were found well below the World Health Organization (WHO) reference limit. The estimated radiation doses for different age groups were found higher than the WHO safe limit of 100 µSv y−1 (from all sources including radon) except for the age groups of 0–12 months infants and 1–3 years children. The results of this study may be useful for future studies on epidemiology, examining hidden faults, uranium exploration etc. [ABSTRACT FROM AUTHOR]

The Bayingobi basin is located in the middle of Central Asia Orogenic Belt, at the intersection of Paleo‐Asian Ocean and Tethys Ocean, as well as the junction of multiple tectonic plates. This unique tectonic setting underpins the basin's intricate history of tectonic activity. To unravel the multifaceted tectono‐thermal evolution within the southwestern region of the basin and to elucidate the implications of sandstone‐hosted uranium mineralization, granitic and clastic rock samples were collected from the Zongnai Mts. uplift and Yingejing depression, and apatite fission track (AFT) dating and thermal history simulation analysis were performed. AFT dating findings reveal that the apparent ages of all samples fall within the range of 244 Ma to 112 Ma. In particular, the bedrock of the Zongnai Mts. and Jurassic detrital apatite fission tracks have undergone complete annealing, capturing the uplift‐cooling age. Meanwhile, the AFT ages of Cretaceous detrital rocks are either equivalent to or notably exceed the age of sedimentary strata, signifying the cooling age of the provenance. A comprehensive examination of AFT ages and palaeocurrent direction analyses suggests that the Cretaceous source in the Tamusu area predominantly originated from the central and southern sectors of the Zongnai Mts. uplift. However, at a certain juncture during the Late Early Cretaceous, the Cretaceous provenance expanded to include the northern part of the Zongnai Mts. uplift. Based on the results of thermal history simulations and previous studies, it is considered that the Tamusu area has undergone four distinct tectonic uplift events since the Late Paleozoic. The first is the Late Permian to Early Triassic (260–240 Ma), which is associated with the closure of the Paleo‐Asian Ocean and the accretionary orogeny within the Alxa region. The second uplift event took place in the Early Jurassic (190–175 Ma) and corresponded to intraplate orogeny following the closure of the Paleo‐Asian Ocean. The third uplift event is the Late Jurassic to Early Cretaceous (160–120 Ma), which is linked to the East Asia's position as the convergence center of multiple tectonic plates during this period. The fourth uplift event is linked to the Late Early Cretaceous (112–100 Ma), driven either by the westward subduction of the eastern Pacific plate or the mantle upwelling resulting from the Bangong–Nujiang oceanic lithosphere subduction and slab break‐off. The primary stress orientation for the first three tectonic uplift phases approximated a nearly SN direction, while the fourth stage featured a principal stress direction of NW. The fourth tectonic uplift event of the Late Early Cretaceous and basaltic eruption thermal event during this period likely exerted a significant influence on the formation of the Tamusu sandstone‐hosted uranium deposit. [ABSTRACT FROM AUTHOR]

Civilian and military nuclear programs of several nations over more than 70 years have led to significant quantities of heterogenous solid, organic, and aqueous radioactive wastes bearing actinides, fission products, and activation products. While many physicochemical treatments have been developed to remediate, decontaminate and reduce waste volumes, they can involve high costs (energy input, expensive sorbants, ion exchange resins, chemical reducing/precipitation agents) or can lead to further secondary waste forms. Microorganisms can directly influence radionuclide solubility, via sorption, accumulation, precipitation, redox, and volatilization pathways, thus offering a more sustainable approach to remediation or effluent treatments. Much work to date has focused on fundamentals or laboratory-scale remediation trials, but there is a paucity of information toward field-scale bioremediation and, to a lesser extent, toward biological liquid effluent treatments. From the few biostimulation studies that have been conducted at legacy weapon production/test sites and uranium mining and milling sites, some marked success via bioreduction and biomineralisation has been observed. However, rebounding of radionuclide mobility from (a)biotic scale-up factors are often encountered. Radionuclide, heavy metal, co-contaminant, and/or matrix effects provide more challenging conditions than traditional industrial wastewater systems, thus innovative solutions via indirect interactions with stable element biogeochemical cycles, natural or engineered cultures or communities of metal and irradiation tolerant strains and reactor design inspirations from existing metal wastewater technologies, are required. This review encompasses the current state of the art in radionuclide biogeochemistry fundamentals and bioremediation and establishes links toward transitioning these concepts toward future radioactive effluent treatments. [ABSTRACT FROM AUTHOR]