189 research outputs found

    Removal of Fluoride from Mine Water via Adsorption for Land-Applied Soil Amendment

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    The team researched, designed, and economically analyzed a full-scale adsorption column system to be applied in mining processes that leave high amounts of fluoride in their effluent. This system was designed to remove fluoride from water saturated with calcium sulfate, as calcium sulfate is present in high amounts in certain mining processes. Currently, high density sludge (HDS) is commonly employed to reduce fluoride concentrations, but due to solubility limits the sludge treatment cannot lower fluoride below 10 mg/L (ppm). The current enforceable EPA standard for discharged water is at 4 mg/L (ppm), although mining companies anticipate that this standard will soon be lowered to 2 ppm. The team was tasked with designing a process to lower 10 ppm fluoride down to 2 ppm. The team investigated various methods such as precipitation, ion exchange, and reverse osmosis to remove fluoride from the system. These methods were not cost-effective and did not produce environmentally friendly byproducts. The team ultimately presented the solution of bone char as an adsorbent, with a byproduct that can be safely applied as a soil amendment. A full-scale facility with two adsorption columns was designed to treat 1000 gpm of water

    Removal of Fluoride from Mine Water via Adsorption for Land-Applied Soil Amendment

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    The Moo Pig Sooie’s researched, designed, and economically analyzed a full-scale adsorption column system to be applied in mining processes that leave high amounts of fluoride in their effluent. This system was designed to remove fluoride from water saturated with calcium sulfate, as calcium sulfate is present in high amounts in certain mining processes. Currently, high density sludge (HDS) is commonly employed to reduce fluoride concentrations, but due to solubility limits the sludge treatment cannot lower fluoride below 10 mg/L (ppm). The current enforceable EPA standard for discharged water is at 4 mg/L (ppm), although mining companies anticipate that this standard will soon be lowered to 2 ppm. The Moo Pig Sooie’s were tasked with designing a process to lower 10 ppm fluoride down to 2 ppm. Moo Pig Sooie investigated various methods such as precipitation, ion exchange, and reverse osmosis to remove fluoride from the system. These methods were not cost-effective and did not produce environmentally friendly byproducts. The team ultimately presented the solution of bone char as an adsorbent, with a byproduct that can be safely applied as a soil amendment. A full-scale facility with two adsorption columns was designed to treat 1000 gpm of water

    Removal of Fluoride from Mine Water via Adsorption for Land-Applied Soil Amendment

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    The process of mining minerals and elements from ores and rocks creates acid rock drainage (ARD). This drainage is water that contains heavy metals and minerals that can be dangerous for human consumption or damaging to the environment. The mining industry has employed various water treatment methods to prevent these metals and minerals from being discharged into water sources such as ponds, lakes, and streams. Currently, the most used treatment process in the mining industry is a cost-effective highdensity sludge (HDS) process. This method reduces the concentration of metals and elements with the use of lime/limestone. However, the concentration of fluoride is not reduced to Environmental Protection Agency (EPA) standards, and so it is necessary to design a fluoride removal system. Reverse osmosis (RO) was considered as well as precipitation, ion exchange, and adsorption by media such as biochars, bone char, and activated alumina. Although RO is perhaps the most obvious solution to reducing fluoride concentrations, this method was eliminated due to expensive overhead and maintenance costs. Many metals and compounds present in the mine water will lead to severe scaling and precipitates collecting in the membrane, requiring constant upkeep and high maintenance costs. Precipitation was eliminated because it produced a byproduct only suitable for landfilling, and ion exchange was eliminated due to its high cost and complications with competitive ions. Adsorption was chosen as a viable option for fluoride removal because of its low cost and environmentally friendly byproduct generation. The adsorption media was chosen based on a ranking system designed by our team. This system provided a way for our team to compare the adsorption capacity, rate of adsorption, byproduct application, and price per ton for each adsorbent. From this ranking system, Moo Pig Sooie is presenting a solution of cow bone char as a fluoride adsorbent. This type of biochar can be bought pre-charred and can be land applied as a fertilizer once the char is spent. A full-scale facility was designed to treat 1000 gallons per minute (GPM) of mine water 24 hours a day, seven days a week, for eight months out of the year. To achieve this flowrate and timeline, two packed beds with volumes of 8,900 ft3 each were designed to run in parallel to ensure loading does not occur until the 168-hour mark, the end of the work week. Once the bone char is loaded, the spent bone char will be hauled offsite to be land applied in soil that is naturally slightly acidic. Our experimental results indicate that minimal amounts of fluoride are stripped from bone char in acidic environments. Applying spent bone char to soil presented a desirable environmentally friendly solution for our byproduct. The overall capital cost of a full-scale facility is approximately 750,894withayearlyoperatingcostof750,894 with a yearly operating cost of 4,778,840. Although this is high, the proposed solution will reduce the concentration of fluoride to EPA standards of 2ppm and the process will generate a land-applicable byproduct. Since consuming fluoride in excessive amounts can lead to health issues, public awareness is a necessary aspect of this solution. Citizens affected by the application of fluoride to their soil and water sources should be regularly involved in and aware of the fluoride levels in their environment. From our analysis of bone char adsorption, Moo Pig Sooie believes this type of treatment is a beneficial, cost effective, and sustainable solution for mining facilities that generate high concentrations of fluoride in their water

    Removal of Fluoride from Mine Water via Adsorption for Land-Applied Soil Amendment

    Get PDF
    The process of mining minerals and elements from ores and rocks creates acid rock drainage (ARD). This drainage is water that contains heavy metals and minerals that can be dangerous for human consumption or damaging to the environment. The mining industry has employed various water treatment methods to prevent these metals and minerals from being discharged into water sources such as ponds, lakes, and streams. Currently, the most used treatment process in the mining industry is a cost-effective highdensity sludge (HDS) process. This method reduces the concentration of metals and elements with the use of lime/limestone. However, the concentration of fluoride is not reduced to Environmental Protection Agency (EPA) standards, and so it is necessary to design a fluoride removal system. Reverse osmosis (RO) was considered as well as precipitation, ion exchange, and adsorption by media such as biochars, bone char, and activated alumina. Although RO is perhaps the most obvious solution to reducing fluoride concentrations, this method was eliminated due to expensive overhead and maintenance costs. Many metals and compounds present in the mine water will lead to severe scaling and precipitates collecting in the membrane, requiring constant upkeep and high maintenance costs. Precipitation was eliminated because it produced a byproduct only suitable for landfilling, and ion exchange was eliminated due to its high cost and complications with competitive ions. Adsorption was chosen as a viable option for fluoride removal because of its low cost and environmentally friendly byproduct generation. The adsorption media was chosen based on a ranking system designed by our team. This system provided a way for our team to compare the adsorption capacity, rate of adsorption, byproduct application, and price per ton for each adsorbent. From this ranking system, Moo Pig Sooie is presenting a solution of cow bone char as a fluoride adsorbent. This type of biochar can be bought pre-charred and can be land applied as a fertilizer once the char is spent. A full-scale facility was designed to treat 1000 gallons per minute (GPM) of mine water 24 hours a day, seven days a week, for eight months out of the year. To achieve this flowrate and timeline, two packed beds with volumes of 8,900 ft3 each were designed to run in parallel to ensure loading does not occur until the 168-hour mark, the end of the work week. Once the bone char is loaded, the spent bone char will be hauled offsite to be land applied in soil that is naturally slightly acidic. Our experimental results indicate that minimal amounts of fluoride are stripped from bone char in acidic environments. Applying spent bone char to soil presented a desirable environmentally friendly solution for our byproduct. The overall capital cost of a full-scale facility is approximately 750,894withayearlyoperatingcostof750,894 with a yearly operating cost of 4,778,840. Although this is high, the proposed solution will reduce the concentration of fluoride to EPA standards of 2ppm and the process will generate a land-applicable byproduct. Since consuming fluoride in excessive amounts can lead to health issues, public awareness is a necessary aspect of this solution. Citizens affected by the application of fluoride to their soil and water sources should be regularly involved in and aware of the fluoride levels in their environment. From our analysis of bone char adsorption, Moo Pig Sooie believes this type of treatment is a beneficial, cost effective, and sustainable solution for mining facilities that generate high concentrations of fluoride in their water

    Vertical zonation of testate amoebae in the Elatia Mires, northern Greece : palaeoecological evidence for a wetland response to recent climate change or autogenic processes?

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    The Elatia Mires of northern Greece are unique ecosystems of high conservation value. The mires are climatically marginal and may be sensitive to changing hydroclimate, while northern Greece has experienced a significant increase in aridity since the late twentieth century. To investigate the impact of recent climatic change on the hydrology of the mires, the palaeoecological record was investigated from three near-surface monoliths extracted from two sites. Testate amoebae were analysed as sensitive indicators of hydrology. Results were interpreted using transfer function models to provide quantitative reconstructions of changing water table depth and pH. AMS radiocarbon dates and 210Pb suggest the peats were deposited within the last c. 50 years, but do not allow a secure chronology to be established. Results from all three profiles show a distinct shift towards a more xerophilic community particularly noted by increases in Euglypha species. Transfer function results infer a distinct lowering of water tables in this period. A hydrological response to recent climate change is a tenable hypothesis to explain this change; however other possible explanations include selective test decay, vertical zonation of living amoebae, ombrotrophication and local hydrological change. It is suggested that a peatland response to climatic change is the most probable hypothesis, showing the sensitivity of marginal peatlands to recent climatic change

    Endogenous Avian Leukosis Virus subgroup E elements of the chicken reference genome

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    The chicken reference genome contains two endogenous Avian Leukosis Virus subgroup E (ALVE) insertions, but gaps and unresolved repetitive sequences in previous assemblies has hindered their precise characterisation. Detailed analysis of the most recent reference genome (GRCg6a) now shows both ALVEs within contiguous chromosome assemblies for the first time. ALVE6 (ALVE-JFevA) and ALVE-JFevB are both located on chromosome 1, with ALVE6 close to the p arm telomere. ALVE-JFevB is a structurally intact element containing the ALVE gag, pol and env genes, and is capable of forming replication competent viruses. In contrast, ALVE6 (ALVE-JFevA) contains a 3352 bp 5’ truncation and lacks the entire 5’ LTR and gag gene. Despite this, ALVE6 remains able to produce intact envelope protein, likely due to a mutation in the recognition site for a known inhibitory miRNA (miR-155). Whole genome resequencing datasets from layers, broilers and three independent sources of wild-caught red junglefowl were surveyed for the presence of each of these reference genome ALVEs. ALVE-JFevB was found in no other chicken or red junglefowl genomes, whereas ALVE6 was identified in some layers, broilers and native breeds, but not within any other red junglefowl genome. Improved assembly contiguity has facilitated better characterisation of the two ALVEs of the chicken reference genome. However, both the limited ALVE content and unique presence of ALVE-JFevB suggests that the reference individual is unrepresentative of ancestral Gallus gallus ALVE diversity

    Varicella zoster virus infection of highly pure terminally differentiated human neurons

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    In vitro analyses of varicella zoster virus (VZV) reactivation from latency in human ganglia have been hampered by the inability to isolate virus by explantation or cocultivation techniques. Furthermore, attempts to study interaction of VZV with neurons in experimentally infected ganglion cells in vitro have been impaired by the presence of nonneuronal cells, which become productively infected and destroy the cultures. We have developed an in vitro model of VZV infection in which highly pure (>95 %) terminally differentiated human neurons derived from pluripotent stem cells were infected with VZV. At 2 weeks post-infection, infected neurons appeared healthy compared to VZV-infected human fetal lung fibroblasts (HFLs), which developed a cytopathic effect (CPE) within 1 week. Tissue culture medium from VZV-infected neurons did not produce a CPE in uninfected HFLs and did not contain PCR-amplifiable VZV DNA, but cocultivation of infected neurons with uninfected HFLs did produce a CPE. The nonproductively infected neurons contained multiple regions of the VZV genome, as well as transcripts and proteins corresponding to VZV immediate-early, early, and late genes. No markers of the apoptotic caspase cascade were detected in healthy-appearing VZV-infected neurons. VZV infection of highly pure terminally differentiated human neurons provides a unique in vitro system to study the VZV-neuronal relationship and the potential to investigate mechanisms of VZV reactivation

    Testate amoebae in pollen slides

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    Among the non-pollen micro-fossils commonly encountered in Quaternary sediment samples prepared for pollen analysis are many shells of testate amoebae. Testate amoebae are eukaryotic micro-organisms which are increasingly used in ecological and palaeoecological studies, particularly as indicators of hydrological change in Sphagnum-dominated peatlands. In this study we address the extent to which testate amoebae are used in palynological research, the key challenges to more widespread use, and the extent to which ecological information is retained in the testate amoeba assemblages of standard palynological slides. To achieve this we review the literature on the use of testate amoebae in palynology, compare testate amoeba records produced by palynological and water-based preparation methods and carry out simulations using previously-derived datasets. Our results show that testate amoebae are widely encountered in Quaternary palynological studies, primarily in peatlands, but the information which they can provide is undermined by limited taxonomic knowledge. Many taxa are destroyed in pollen preparations, but for taxa that are retained patterns of abundance parallel those determined using water-based preparation methods. Although the loss of sensitive taxa limits the ecological information contained in testate amoeba assemblages the information preserved is likely to be useful in a multiproxy approach to palaeoenvironmental reconstruction. To help improve taxonomic awareness and encourage the use of testate amoebae in palynology we present a basic introduction to testate amoeba taxonomy and a guide to the taxonomic literature

    Measuring Resilience in Adult Women Using the 10-Items Connor-Davidson Resilience Scale (CD-RISC). Role of Trauma Exposure and Anxiety Disorders

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    International audiencePURPOSE: Resilience is the ability of individuals to adapt positively in the face of trauma. Little is known, however, about lifetime factors affecting resilience. METHODS: We assessed the effects of psychiatric disorder and lifetime trauma history on the resilience self-evaluation using the Connor-Davidson Resilience Scale (CD-RISC-10) in a high-risk-women sample. Two hundred and thirty eight community-dwelling women, including 122 participants in a study of breast cancer survivors and 116 participants without previous history of cancer completed the CD-RISC-10. Lifetime psychiatric symptoms were assessed retrospectively using two standardized psychiatric examinations (Mini International Neuropsychiatric Interview and Watson's Post-Traumatic Stress Disorder Inventory). RESULTS: Multivariate logistic regression adjusted for age, education, trauma history, cancer, current psychiatric diagnoses, and psychoactive treatment indicated a negative association between current psychiatric disorder and high resilience compared to low resilience level (OR = 0.44, 95% CI [0.21-0.93]). This was related to anxiety and not mood disorder. A positive and independent association with a trauma history was also observed (OR = 3.18, 95% CI [1.44-7.01]). CONCLUSION: Self-evaluation of resilience is influenced by both current anxiety disorder and trauma history. The independent positive association between resilience and trauma exposure may indicate a "vaccination" effect. This finding need to be taken into account in future studies evaluating resilience in general or clinical populations
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