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1
Tesoriero, Anthony J., John H. Duff, David A. Saad, Norman E. Spahr, and David M. Wolock. "Vulnerability of Streams to Legacy Nitrate Sources." Environmental Science & Technology 47, no. 8 (2013): 3623–29. http://dx.doi.org/10.1021/es305026x.
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Exner, Mary E., Aaron J. Hirsh, and Roy F. Spalding. "Nebraska's groundwater legacy: Nitrate contamination beneath irrigated cropland." Water Resources Research 50, no. 5 (2014): 4474–89. http://dx.doi.org/10.1002/2013wr015073.
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Weitzman, Julie N., and Jason P. Kaye. "Nitrate retention capacity of milldam-impacted legacy sediments and relict A horizon soils." SOIL 3, no. 2 (2017): 95–112. http://dx.doi.org/10.5194/soil-3-95-2017.
Повний текст джерелаАнотація:
Abstract. While eutrophication is often attributed to contemporary nutrient pollution, there is growing evidence that past practices, like the accumulation of legacy sediment behind historic milldams, are also important. Given their prevalence, there is a critical need to understand how N flows through, and is retained in, legacy sediments to improve predictions and management of N transport from uplands to streams in the context of climatic variability and land-use change. Our goal was to determine how nitrate (NO3−) is cycled through the soil of a legacy-sediment-strewn stream before and after soil drying. We extracted 10.16 cm radius intact soil columns that extended 30 cm into each of the three significant soil horizons at Big Spring Run (BSR) in Lancaster, Pennsylvania: surface legacy sediment characterized by a newly developing mineral A horizon soil, mid-layer legacy sediment consisting of mineral B horizon soil and a dark, organic-rich, buried relict A horizon soil. Columns were first preincubated at field capacity and then isotopically labeled nitrate (15NO3−) was added and allowed to drain to estimate retention. The columns were then air-dried and subsequently rewet with N-free water and allowed to drain to quantify the drought-induced loss of 15NO3− from the different horizons. We found the highest initial 15N retention in the mid-layer legacy sediment (17 ± 4 %) and buried relict A soil (14 ± 3 %) horizons, with significantly lower retention in the surface legacy sediment (6 ± 1 %) horizon. As expected, rewetting dry soil resulted in 15N losses in all horizons, with the greatest losses in the buried relict A horizon soil, followed by the mid-layer legacy sediment and surface legacy sediment horizons. The 15N remaining in the soil following the post-drought leaching was highest in the mid-layer legacy sediment, intermediate in the surface legacy sediment, and lowest in the buried relict A horizon soil. Fluctuations in the water table at BSR which affect saturation of the buried relict A horizon soil could lead to great loses of NO3− from the soil, while vertical flow through the legacy-sediment-rich soil profile that originates in the surface has the potential to retain more NO3−. Restoration that seeks to reconnect the groundwater and surface water, which will decrease the number of drying–rewetting events imposed on the relict A horizon soils, could initially lead to increased losses of NO3− to nearby stream waters.
4
Green, Stefan J., Om Prakash, Puja Jasrotia, et al. "Denitrifying Bacteria from the Genus Rhodanobacter Dominate Bacterial Communities in the Highly Contaminated Subsurface of a Nuclear Legacy Waste Site." Applied and Environmental Microbiology 78, no. 4 (2011): 1039–47. http://dx.doi.org/10.1128/aem.06435-11.
Повний текст джерелаАнотація:
ABSTRACTThe effect of long-term mixed-waste contamination, particularly uranium and nitrate, on the microbial community in the terrestrial subsurface was investigated at the field scale at the Oak Ridge Integrated Field Research Challenge (ORIFRC) site in Oak Ridge, TN. The abundance, community composition, and distribution of groundwater microorganisms were examined across the site during two seasonal sampling events. At representative locations, subsurface sediment was also examined from two boreholes, one sampled from the most heavily contaminated area of the site and another from an area with low contamination. A suite of DNA- and RNA-based molecular tools were employed for community characterization, including quantitative PCR of rRNA and nitrite reductase genes, community composition fingerprinting analysis, and high-throughput pyrotag sequencing of rRNA genes. The results demonstrate that pH is a major driver of the subsurface microbial community structure and that denitrifying bacteria from the genusRhodanobacter(classGammaproteobacteria) dominate at low pH. The relative abundance of bacteria from this genus was positively correlated with lower-pH conditions, and these bacteria were abundant and active in the most highly contaminated areas. Other factors, such as the concentration of nitrogen species, oxygen level, and sampling season, did not appear to strongly influence the distribution ofRhodanobacterbacteria. The results indicate that these organisms are acid-tolerant denitrifiers, well suited to the acidic, nitrate-rich subsurface conditions, and pH is confirmed as a dominant driver of bacterial community structure in this contaminated subsurface environment.
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Ehrhardt, Sophie, Rohini Kumar, Jan H. Fleckenstein, Sabine Attinger, and Andreas Musolff. "Trajectories of nitrate input and output in three nested catchments along a land use gradient." Hydrology and Earth System Sciences 23, no. 9 (2019): 3503–24. http://dx.doi.org/10.5194/hess-23-3503-2019.
Повний текст джерелаАнотація:
Abstract. Increased anthropogenic inputs of nitrogen (N) to the biosphere during the last few decades have resulted in increased groundwater and surface water concentrations of N (primarily as nitrate), posing a global problem. Although measures have been implemented to reduce N inputs, they have not always led to decreasing riverine nitrate concentrations and loads. This limited response to the measures can either be caused by the accumulation of organic N in the soils (biogeochemical legacy) – or by long travel times (TTs) of inorganic N to the streams (hydrological legacy). Here, we compare atmospheric and agricultural N inputs with long-term observations (1970–2016) of riverine nitrate concentrations and loads in a central German mesoscale catchment with three nested subcatchments of increasing agricultural land use. Based on a data-driven approach, we assess jointly the N budget and the effective TTs of N through the soil and groundwater compartments. In combination with long-term trajectories of the C–Q relationships, we evaluate the potential for and the characteristics of an N legacy. We show that in the 40-year-long observation period, the catchment (270 km2) with 60 % agricultural area received an N input of 53 437 t, while it exported 6592 t, indicating an overall retention of 88 %. Removal of N by denitrification could not sufficiently explain this imbalance. Log-normal travel time distributions (TTDs) that link the N input history to the riverine export differed seasonally, with modes spanning 7–22 years and the mean TTs being systematically shorter during the high-flow season as compared to low-flow conditions. Systematic shifts in the C–Q relationships were noticed over time that could be attributed to strong changes in N inputs resulting from agricultural intensification before 1989, the break-down of East German agriculture after 1989 and the seasonal differences in TTs. A chemostatic export regime of nitrate was only found after several years of stabilized N inputs. The changes in C–Q relationships suggest a dominance of the hydrological N legacy over the biogeochemical N fixation in the soils, as we expected to observe a stronger and even increasing dampening of the riverine N concentrations after sustained high N inputs. Our analyses reveal an imbalance between N input and output, long time-lags and a lack of significant denitrification in the catchment. All these suggest that catchment management needs to address both a longer-term reduction of N inputs and shorter-term mitigation of today's high N loads. The latter may be covered by interventions triggering denitrification, such as hedgerows around agricultural fields, riparian buffers zones or constructed wetlands. Further joint analyses of N budgets and TTs covering a higher variety of catchments will provide a deeper insight into N trajectories and their controlling parameters.
6
Lautz, Laura K., Sarah H. Ledford, and Julio Beltran. "Legacy effects of cemeteries on groundwater quality and nitrate loads to a headwater stream." Environmental Research Letters 15, no. 12 (2020): 125012. http://dx.doi.org/10.1088/1748-9326/abc914.
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Leitner, Sonja, Thomas Dirnböck, Johannes Kobler, and Sophie Zechmeister-Boltenstern. "Legacy effects of drought on nitrate leaching in a temperate mixed forest on karst." Journal of Environmental Management 262 (May 2020): 110338. http://dx.doi.org/10.1016/j.jenvman.2020.110338.
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Jaunat, J., E. Garel, F. Huneau, et al. "Combinations of geoenvironmental data underline coastal aquifer anthropogenic nitrate legacy through groundwater vulnerability mapping methods." Science of The Total Environment 658 (March 2019): 1390–403. http://dx.doi.org/10.1016/j.scitotenv.2018.12.249.
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Riedel, Thomas, Christine Kübeck, and Markus Quirin. "Legacy nitrate and trace metal (Mn, Ni, As, Cd, U) pollution in anaerobic groundwater: Quantifying potential health risk from “the other nitrate problem”." Applied Geochemistry 139 (April 2022): 105254. http://dx.doi.org/10.1016/j.apgeochem.2022.105254.
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Guillaumot, Luca, Jean Marçais, Camille Vautier, et al. "A hillslope-scale aquifer-model to determine past agricultural legacy and future nitrate concentrations in rivers." Science of The Total Environment 800 (December 2021): 149216. http://dx.doi.org/10.1016/j.scitotenv.2021.149216.
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11
Wang, Lei, Da-Cheng Hao, Sisi Fan, et al. "N2O Emission and Nitrification/Denitrification Bacterial Communities in Upland Black Soil under Combined Effects of Early and Immediate Moisture." Agriculture 12, no. 3 (2022): 330. http://dx.doi.org/10.3390/agriculture12030330.
Повний текст джерелаАнотація:
Soil moisture is the major factor influencing microbial properties and nitrous oxide (N2O) production. Agricultural soils can be probed under wetting, wet/dry alternating, and constant moisture conditions to evaluate the combined effects of early (previous) and immediate (current) moisture on N2O emission and nitrification/denitrification. In view of the water history of upland black soil, five moisture regimes comprising different antecedent and present water holding capacity (WHC) levels were set up in the microcosm study. The 20% WHC was adopted as the initial legacy moisture, while three immediate water statuses include constant WHC, dry-wet cycle, and incremental moisture. Quantitative PCR and 16S rRNA amplicon sequencing were used to assess the impact of current and previous moisture on the bacterial community composition and abundance of nitrification/denitrification genes (amoA, nirS, and nosZ); the soil physicochemical properties, and N2O emission were monitored. The N2O production and nitrifying-denitrifying microbial communities were influenced by the antecedent moisture and pattern of the dry-wet cycle. The nitrifying-denitrifying microbial communities, especially members of β-/γ-Proteobacteria, Bacteroidetes and Gemmatimonadetes, in black soil were important in explaining the variation of N2O production. The key taxonomic groups in response to the moisture alteration, e.g., Acidobacteria, Sphingobacteriia, Deltaproteobacteria, Methylobacterium, Gemmatimonas and Pseudarthrobacter, etc., were also highlighted. The soil nitrate, ammonium nitrogen, N2O emission, nitrification/denitrification and mineralization were profoundly impacted by water regimes and showed statistically significant correlation with specific bacterial genera; the nitrite/nitrate reduction to ammonium could be boosted by high moisture. Both nitrifier denitrification and heterotrophic denitrification could be enhanced substantially when the black soil moisture was increased to above 60% WHC. These findings help evaluate the effects of the water mode on the N2O emission from black soil, as well as the associated impacts on both soil fertility and the global environment.
12
Jessen, Søren, Dieke Postma, Laerke Thorling, Sascha Müller, Jari Leskelä, and Peter Engesgaard. "Decadal variations in groundwater quality: A legacy from nitrate leaching and denitrification by pyrite in a sandy aquifer." Water Resources Research 53, no. 1 (2017): 184–98. http://dx.doi.org/10.1002/2016wr018995.
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Prakash, Om, Stefan J. Green, Puja Jasrotia, et al. "Rhodanobacter denitrificans sp. nov., isolated from nitrate-rich zones of a contaminated aquifer." International Journal of Systematic and Evolutionary Microbiology 62, Pt_10 (2012): 2457–62. http://dx.doi.org/10.1099/ijs.0.035840-0.
Повний текст джерелаАнотація:
Bacterial strains 2APBS1T and 116-2 were isolated from the subsurface of a nuclear legacy waste site where the sediments are co-contaminated with large amounts of acids, nitrate, metal radionuclides and other heavy metals. A combination of physiological and genetic assays indicated that these strains represent the first member of the genus Rhodanobacter shown to be capable of complete denitrification. Cells of strain 2APBS1T and 116-2 were Gram-negative, non-spore-forming rods, 3–5 µm long and 0.25–0.5 µm in diameter. The isolates were facultative anaerobes, and had temperature and pH optima for growth of 30 °C and pH 6.5; they were able to tolerate up to 2.0 % NaCl, although growth improved in its absence. Strains 2APBS1T and 116-2 contained fatty acid and quinone (ubiquinone-8; 100 %) profiles that are characteristic features of the genus Rhodanobacter . Although strains 2APBS1T and 116-2 shared high 16S rRNA gene sequence similarity with Rhodanobacter thiooxydans LCS2T (>99 %), levels of DNA–DNA relatedness between these strains were substantially below the 70 % threshold used to designate novel species. Thus, based on genotypic, phylogenetic, chemotaxonomic and physiological differences, strains 2APBS1T and 116-2 are considered to represent a single novel species of the genus Rhodanobacter , for which the name Rhodanobacter denitrificans sp. nov. is proposed. The type strain is 2APBS1T ( = DSM 23569T = JCM 17641T).
14
Fang, Yilin, Xingyuan Chen, Jesus Gomez Velez, et al. "A multirate mass transfer model to represent the interaction of multicomponent biogeochemical processes between surface water and hyporheic zones (SWAT-MRMT-R 1.0)." Geoscientific Model Development 13, no. 8 (2020): 3553–69. http://dx.doi.org/10.5194/gmd-13-3553-2020.
Повний текст джерелаАнотація:
Abstract. Surface water quality along river corridors can be modulated by hyporheic zones (HZs) that are ubiquitous and biogeochemically active. Watershed management practices often ignore the potentially important role of HZs as a natural reactor. To investigate the effect of hydrological exchange and biogeochemical processes on the fate of nutrients in surface water and HZs, a novel model, SWAT-MRMT-R, was developed coupling the Soil and Water Assessment Tool (SWAT) watershed model and the reaction module from a flow and reactive transport code (PFLOTRAN). SWAT-MRMT-R simulates concurrent nonlinear multicomponent biogeochemical reactions in both the channel water and its surrounding HZs, connecting the channel water and HZs through hyporheic exchanges using multirate mass transfer (MRMT) representation. Within the model, HZs are conceptualized as transient storage zones with distinguished exchange rates and residence times. The biogeochemical processes within HZs are different from those in the channel water. Hyporheic exchanges are modeled as multiple first-order mass transfers between the channel water and HZs. As a numerical example, SWAT-MRMT-R is applied to the Hanford Reach of the Columbia River, a large river in the United States, focusing on nitrate dynamics in the channel water. Major nitrate contaminants entering the Hanford Reach include those from the legacy waste, irrigation return flows (irrigation water that is not consumed by crops and runs off as point sources to the stream), and groundwater seepage resulting from irrigated agriculture. A two-step reaction sequence for denitrification and an aerobic respiration reaction is assumed to represent the biogeochemical transformations taking place within the HZs. The spatially variable hyporheic exchange rates and residence times in this example are estimated with the basin-scale Networks with EXchange and Subsurface Storage (NEXSS) model. Our simulation results show that (1), given a residence time distribution, how the exchange fluxes to HZs are approximated when using MRMT can significantly change the amount of nitrate consumption in HZs through denitrification and (2) source locations of nitrate have a different impact on surface water quality due to the spatially variable hyporheic exchanges.
15
Stewart, Martin W. A., Eric R. Vance, Sam A. Moricca, et al. "Immobilisation of Higher Activity Wastes from Nuclear Reactor Production of99Mo." Science and Technology of Nuclear Installations 2013 (2013): 1–16. http://dx.doi.org/10.1155/2013/926026.
Повний текст джерелаАнотація:
A variety of intermediate- and low-level liquid and solid wastes are produced from reactor production of99Mo using UAl alloy or UO2targets and in principle can be collectively or individually converted into waste forms. At ANSTO, we have legacy acidic uranyl-nitrate-rich intermediate level waste (ILW) from the latter, and an alkaline liquid ILW, a U-rich filter cake, plus a shorter lived liquid stream that rapidly decays to low-level waste (LLW) standards, from the former. The options considered consist of cementitious products, glasses, glass-ceramics, or ceramics produced by vitrification or hot isostatic pressing for intermediate-level wastes. This paper discusses the progress in waste form development and processing to treat ANSTO’s ILW streams arising from99Mo. The various waste forms and the reason for the process option chosen will be reviewed. We also address the concerns over adapting our chosen process for use in a hot-cell environment.
16
O'Riordan, Roisin, Jess Davies, Carly Stevens, and John N. Quinton. "The effects of sealing on urban soil carbon and nutrients." SOIL 7, no. 2 (2021): 661–75. http://dx.doi.org/10.5194/soil-7-661-2021.
Повний текст джерелаАнотація:
Abstract. Urban soils are of increasing interest for their potential to provide ecosystem services such as carbon storage and nutrient cycling. Despite this, there is limited knowledge on how soil sealing with impervious surfaces, a common disturbance in urban environments, affects these important ecosystem services. In this paper, we investigate the effect of soil sealing on soil properties, soil carbon and soil nutrient stocks. We undertook a comparative survey of sealed and unsealed green space soils across the UK city of Manchester. Our results reveal that the context of urban soil and the anthropogenic artefacts added to soil have a great influence on soil properties and functions. In general, sealing reduced soil carbon and nutrient stocks compared to green space soil; however, where there were anthropogenic additions of organic and mineral artefacts, this led to increases in soil carbon and nitrate content. Anthropogenic additions led to carbon stocks equivalent to or larger than those in green spaces; this was likely a result of charcoal additions, leading to carbon stores with long residence times. This suggests that in areas with an industrial past, anthropogenic additions can lead to a legacy carbon store in urban soil and make important contributions to urban soil carbon budgets. These findings shed light on the heterogeneity of urban sealed soil and the influence of anthropogenic artefacts on soil functions. Our research highlights the need to gain a further understanding of urban soil processes, in both sealed and unsealed soils, and of the influence and legacy of anthropogenic additions for soil functions and important ecosystem services.
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Ji, Wangjia, Yanan Huang, Bingbing Li, David W. Hopkins, Wenzhao Liu, and Zhi Li. "Legacy nitrate in the deep loess deposits after conversion of arable farmland to non‐fertilized land uses for degraded land restoration." Land Degradation & Development 31, no. 11 (2020): 1355–65. http://dx.doi.org/10.1002/ldr.3532.
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McBeth, J. M., J. R. Lloyd, G. T. W. Law, F. R. Livens, I. T. Burke, and K. Morris. "Redox interactions of technetium with iron-bearing minerals." Mineralogical Magazine 75, no. 4 (2011): 2419–30. http://dx.doi.org/10.1180/minmag.2011.075.4.2419.
Повний текст джерелаАнотація:
AbstractIron minerals influence the environmental redox behaviour and mobility of metals including the long-lived radionuclide technetium. Technetium is highly mobile in its oxidized form pertechnetate (Tc(VII)O4–), however, when it is reduced to Tc(IV) it immobilizes readily via precipitation or sorption. In low concentration tracer experiments, and in higher concentration XAS experiments, pertechnetate was added to samples of biogenic and abiotically synthesized Fe(II)-bearing minerals (bio-magnetite, bio-vivianite, bio-siderite and an abiotically precipitated Fe(II) gel). Each mineral scavenged different quantities of Tc(VII) from solution with essentially complete removal in Fe(II)-gel and bio-magnetite systems and with 84±4% removal onto bio-siderite and 68±5% removal onto bio-vivianite over 45 days. In select, higher concentration, Tc XAS experiments, XANES spectra showed reductive precipitation to Tc(IV) in all samples. Furthermore, EXAFS spectra for bio-siderite, bio-vivianite and Fe(II)-gel showed that Tc(IV) was present as short range ordered hydrous Tc(IV)O2-like phases in the minerals and for some systems suggested possible incorporation in an octahedral coordination environment. Low concentration reoxidation experiments with air-, and in the case of the Fe(II) gel, nitrate-oxidation of the Tc(IV)-labelled samples resulted in only partial remobilization of Tc. Upon exposure to air, the Tc bound to the Fe-minerals was resistant to oxidative remobilization with a maximum of ∼15% Tc remobilized in the bio-vivianite system after 45 days of air exposure. Nitrate mediated oxidation of Fe(II)-gel inoculated with a stable consortium of nitrate-reducing, Fe(II)-oxidizing bacteria showed only 3.8±0.4% remobilization of reduced Tc(IV), again highlighting the recalcitrance of Tc(IV) to oxidative remobilization in Fe-bearing systems. The resultant XANES spectra of the reoxidized minerals showed Tc(IV)-like spectra in the reoxidized Fe-phases. Overall, this study highlights the role that Fe-bearing biogenic mineral phases have in controlling reductive scavenging of Tc(VII) to hydrous TcO2-like phases onto a range of Fe(II)-bearing minerals. In addition, it suggests that on reoxidation of these phases, Fe-bound Tc(IV) may be octahedrally coordinated and is largely recalcitrant to reoxidation over medium-term timescales. This has implications when considering remediation approaches and in predictions of the long-term fate of Tc in the nuclear legacy.
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Krpec, P., M. Horáček, and B. Šarapatka. "A comparison of the use of local legacy soil data and global datasets for hydrological modelling a small-scale watersheds: Implications for nitrate loading estimation." Geoderma 377 (November 2020): 114575. http://dx.doi.org/10.1016/j.geoderma.2020.114575.
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Vance, Eric R., S. A. Moricca, and M. W. A. Stewart. "Progress at ANSTO on a Synroc Plant for Intermediate-Level Waste from Reactor Production of 99Mo." Advances in Science and Technology 94 (October 2014): 111–14. http://dx.doi.org/10.4028/www.scientific.net/ast.94.111.
Повний текст джерелаАнотація:
Intermediate level waste from ANSTO’s expanded 99Mo production plant will consist of ~5000L/year of 6M NaOH + 1.4 NaAlO2 + fission products. Detailed engineering is being carried out on a synroc plant to immobilise this waste in a glass-ceramic, with completion scheduled for 2016. The liquid waste will be mixed with precursors and dried before being calcined in a reducing atmosphere to control fission product volatility. The calcine will be transferred to 30L metal cans which will be hot isostatically pressed at 1000°C/30MPa for 2h, then cooled to room temperature and stored preparatory to final disposal. Laboratory scale waste form material will pass 90°C PCT tests. In addition, legacy intermediate level uranyl nitrate-based liquid waste from 99Mo production at ANSTO between the 1980s and 2005 via irradiation of UO2 targets will also be immobilised by the same process to form a Synroc-type waste form. Some examples illustrating the wide applicability of hot isostatic pressing to consolidate nuclear waste forms will be given showing the advantages for particular wastes, notably high waste loadings and the absence of off-gas in the high temperature consolidation step. The immobilisation of a variety of low-level liquid and solid wastes from 99Mo production will also be discussed.
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Parsons, Chris T., Fereidoun Rezanezhad, David W. O'Connell, and Philippe Van Cappellen. "Sediment phosphorus speciation and mobility under dynamic redox conditions." Biogeosciences 14, no. 14 (2017): 3585–602. http://dx.doi.org/10.5194/bg-14-3585-2017.
Повний текст джерелаАнотація:
Abstract. Anthropogenic nutrient enrichment has caused phosphorus (P) accumulation in many freshwater sediments, raising concerns that internal loading from legacy P may delay the recovery of aquatic ecosystems suffering from eutrophication. Benthic recycling of P strongly depends on the redox regime within surficial sediment. In many shallow environments, redox conditions tend to be highly dynamic as a result of, among others, bioturbation by macrofauna, root activity, sediment resuspension and seasonal variations in bottom-water oxygen (O2) concentrations. To gain insight into the mobility and biogeochemistry of P under fluctuating redox conditions, a suspension of sediment from a hypereutrophic freshwater marsh was exposed to alternating 7-day periods of purging with air and nitrogen gas (N2), for a total duration of 74 days, in a bioreactor system. We present comprehensive data time series of bulk aqueous- and solid-phase chemistry, solid-phase phosphorus speciation and hydrolytic enzyme activities demonstrating the mass balanced redistribution of P in sediment during redox cycling. Aqueous phosphate concentrations remained low ( ∼ 2.5 µM) under oxic conditions due to sorption to iron(III) oxyhydroxides. During anoxic periods, once nitrate was depleted, the reductive dissolution of iron(III) oxyhydroxides released P. However, only 4.5 % of the released P accumulated in solution while the rest was redistributed between the MgCl2 and NaHCO3 extractable fractions of the solid phase. Thus, under the short redox fluctuations imposed in the experiments, P remobilization to the aqueous phase remained relatively limited. Orthophosphate predominated at all times during the experiment in both the solid and aqueous phase. Combined P monoesters and diesters accounted for between 9 and 16 % of sediment particulate P. Phosphatase activities up to 2.4 mmol h−1 kg−1 indicated the potential for rapid mineralization of organic P (Po), in particular during periods of aeration when the activity of phosphomonoesterases was 37 % higher than under N2 sparging. The results emphasize that the magnitude and timing of internal P loading during periods of anoxia are dependent on both P redistribution within sediments and bottom-water nitrate concentrations.
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Walji, Khalil, Maja Krzic, Drew Bondar, and Sean M. Smukler. "Nitrogen Dynamics Following Incorporation of 3-Year Old Grassland Set-Asides in the Fraser River Delta of British Columbia." Agronomy 10, no. 9 (2020): 1382. http://dx.doi.org/10.3390/agronomy10091382.
Повний текст джерелаАнотація:
Short-term grassland set-asides (GLSA) have been incorporated into intensive annual crop rotations to improve soil quality. The legacy of the GLSA to subsequent annual crops, however, is not well understood. The objective of this study was to determine the impacts of 3-year-old GLSA on nitrogen (N) dynamics and the yield of the subsequent cash crop. A regional analysis was conducted over two years, utilizing eight production fields transitioning from GLSA, paired with fields in continuous annual crop rotation (ACR) with matching management. A controlled plot-scale experiment was also conducted on a single 3-year-old GLSA, comparing fertilizer types, rates, and timing of incorporation. In each experiment, soils were sampled every 10–14 days for ammonium (NH4+-N) and nitrate (NO3−-N), along with ion probes, installed near the rooting zone to track plant available nitrogen (PAN) throughout the season. The results from the regional analysis are confounding, in 2015 showing that GLSA supplied an additional 18 kg PAN ha−1 compared to ACR but showed no PAN benefits in 2016. The controlled plot-scale experiment highlighted the importance of fertilizer type to subsequent PAN, showing synthetic treatments consistently supplied more PAN than organic. The results from this study suggest that 3-year-old GLSAs can potentially improve PAN to subsequent crops depending on how they are managed.
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Weitzman, Julie N., J. Renée Brooks, Paul M. Mayer, William D. Rugh та Jana E. Compton. "Coupling the dual isotopes of water (δ 2H and δ 18O) and nitrate (δ 15N and δ 18O): a new framework for classifying current and legacy groundwater pollution". Environmental Research Letters 16, № 4 (2021): 045008. http://dx.doi.org/10.1088/1748-9326/abdcef.
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Rutkowska, Agnieszka, and Piotr Skowron. "Productive and Environmental Consequences of Sixteen Years of Unbalanced Fertilization with Nitrogen and Phosphorus—Trials in Poland with Oilseed Rape, Wheat, Maize and Barley." Agronomy 10, no. 11 (2020): 1747. http://dx.doi.org/10.3390/agronomy10111747.
Повний текст джерелаАнотація:
Two factorial field experiments were carried out between 2003 and 2018 in the Experimental Stations in Eastern and Western Poland using four crop rotations with winter oilseed rape, winter wheat, maize and spring barley. The initial value of phosphorus (P) in Grabów soil was 69.8 mg P·kg−1 soil and in Baborówko soil it was 111.3 mg P·kg−1 soil (Egner-Riehm Double-Lactate DL). P fertilizer was added annually at 39 kg P·ha−1 under winter oilseed rape, 35 kg P·ha−1 under maize and 31 kg P·ha−1 under wheat and barley using superphosphate and nitrogen (N), which was added at five levels (30–250 kg N·ha−1) per year as ammonium nitrate in addition to controls with no added fertilizer. Through the several years of the experiment, P fertilizer had no effect on crop N use efficiency (NUE) nor crop productivity. There was significant soil P mining particularly in the high-N fertilizer trials causing a reduction in the content of available soil P by up to 35%. This work recommends that, based on soil P analysis, P fertilizer should not be added to high-P soils. This practice may continue uninterrupted for several years (16 in this case) until the excess soil P has been reduced. This mechanism of removal of “legacy” P from soil has major implications in reducing runoff P into the Baltic Sea drainage area and other water bodies.
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Rosemarin, Arno, Nelson Ekane, and Kim Andersson. "Phosphorus Flows, Surpluses, and N/P Agronomic Balancing When Using Manure from Pig and Poultry Farms." Agronomy 11, no. 11 (2021): 2228. http://dx.doi.org/10.3390/agronomy11112228.
Повний текст джерелаАнотація:
The pig and poultry industries continue to grow across the world and together they provide the majority of meat consumed. The European Union (EU) in particular has the highest global relative meat production by monogastrics (i.e., pig and poultry). The fate of phosphorus (P) in pig and poultry farming was studied, accounting for P content in feed, animals, manure, soil, and runoff. P input from manure, and P offtake in crops receiving manure, were plotted against each other to arrive at “safe” P loading rates, in order to minimize soil P surpluses along the lines of the EU Nitrogen Expert Panel in their work with nitrogen (N). However, it was observed that it is the N/P ratio and the background soil P levels that determine whether a certain manure will end up producing surplus levels of soil P. Critical N/P weight ratios were derived over different crop P offtake rates when applying stored manure to croplands. At spreading rates of 170 and 250 kgN/ha/year and a crop P offtake of 15 or 30 kgP/ha/year, stored pig and chicken manure result in soil P surpluses. An important factor in determining effective N/P ratios is the plant availability of N in stored manure, which runs at around 47%, estimated from previously published results. The minimization of N losses to the atmosphere and to groundwater in housing, storage, and spreading of manure has a major impact on the N/P weight ratio of the manure that ends up on fields. In most cases, half of the ex-animal N content has been lost in stored or degraded manure, with N/P weight ratios running at two and less. Following only the EU Nitrates Directive, which allows for a maximum of 170 kgN/ha/year in NVZs (Nitrate Vulnerable Zones), will often result in soil P surpluses leading to runoff losses to adjacent water bodies. Therefore, for the pig and poultry industries to continue thriving, measures are required to better manage manure, including improved storage and spreading techniques, acidification, separation, struvite extraction and ammonia stripping of pig slurry, and drying and pelleting of poultry litter. This way, excess manure and derived biofertilizers from animal farms can find their way back into the commercial market, instead of ending up as legacy P in watersheds and coastal zones.
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Brown, Bryan, and Eric R. Gallandt. "A Systems Comparison of Contrasting Organic Weed Management Strategies." Weed Science 66, no. 1 (2017): 109–20. http://dx.doi.org/10.1017/wsc.2017.34.
Повний текст джерелаАнотація:
Weed management strategies differ in their ability to control weeds, and often have unique agroecological implications. To provide growers with an improved sense of trade-offs between weed control and ecological effects, we implemented several prominent organic weed management strategies in yellow onion in 2014 and 2015. Strategies included cultivation of weed seedlings during the early, weed-sensitive “critical period” of the crop; frequent cultivation events to ensure “zero seed rain”; and weed suppression with polyethylene or natural mulches. As expected, end-of-season weed biomass and weed seed production were greatest in the critical period system and nearly zero for the zero seed rain system. Weeds were also well controlled in natural mulch systems. Average onion yield per treatment was 50.7 Mg ha−1. In 2014, the critical period system and the polyethylene mulch systems demonstrated yield loss, likely due to weed competition and excessive soil temperature, respectively. Onion soluble solids content was also diminished in these systems in 2014, but bulb firmness was greatest in unmulched systems. Carabid beetles, earthworms, soil compaction, soil nitrate, and microbial biomass were affected by weed management strategy, with natural-mulched systems generally performing most favorably. However, these effects were not substantial enough to affect yield of a subsequent sweet corn crop grown in weed-free conditions. In contrast, sweet corn managed with only early-season cultivations demonstrated yield loss (P=0.004) in plots where the critical period treatment was implemented the prior year, indicating that weed competition resulting from abundant weed seed production in that system was the most influential legacy effect of the weed management strategies.
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Kent, Robert, and Matthew K. Landon. "Trends in concentrations of nitrate and total dissolved solids in public supply wells of the Bunker Hill, Lytle, Rialto, and Colton groundwater subbasins, San Bernardino County, California: Influence of legacy land use." Science of The Total Environment 452-453 (May 2013): 125–36. http://dx.doi.org/10.1016/j.scitotenv.2013.02.042.
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Bimbato, Stella Mara, Giselle Marques de Araújo, Eduardo Barreto Aguiar, et al. "Segurança Jurídica e o Teor de Nitrato na Cultura de Alface." Ensaios e Ciência C Biológicas Agrárias e da Saúde 26, no. 1 (2022): 10–18. http://dx.doi.org/10.17921/1415-6938.2022v26n1p10-18.
Повний текст джерелаАнотація:
O acúmulo de nitrato (NO3-) nos alimentos ingeridos pode gerar riscos à saúde do consumidor. Os diferentes sistemas de produção de alface (Lactuca sativa) podem alterar a produtividade da cultura e propriedades químicas desta hortaliça, como os teores de nitrato nas folhas. O presente estudo investigou, com base em pesquisas inerentes aos resultados de análises referentes ao teor de nitrato em alfaces convencionais, orgânicas e hidropônicas, que produções estão dentro dos parâmetros estabelecidos pela Organização das Nações Unidas para Agricultura e Alimentação: FAO (Food and Agriculture Organization of the United Nations) no Brasil e Organização Mundial da Saúde (OMS). A pesquisa foi desenvolvida pelo método indutivo-dedutivo proposto por Aristóteles, realizando-se uma análise documental entre os resultados propostos e os parâmetros legais estabelecidos. Verificou-se que os níveis encontrados não violam o princípio da segurança jurídica, de acordo com a teoria dos direitos fundamentais que apoiam o direito à saúde e ao meio ambiente ecologicamente equilibrado. Dentro desse contexto, verificou-se que ausência de legislação específica no Brasil referente aos teores máximos do íon nitrato permitidos em vegetais, não impede a efetivação dos direitos fundamentais à saúde e ao meio ambiente ecologicamente equilibrado, não comprometendo a segurança jurídica que envolve as relações de consumo. Assim, os resultados servem para orientar os produtores de hortaliças, bem como futuramente subsidiar legislação específica sobre o tema no Brasil. Palavras-chave: Segurança Alimentar. Direito à Saúde. Lactuca sativa. Limites de NO3- Abstract The nitrate accumulation (NO3-) in the ingested food can generate risks to the consumer's health. The different production systems of lettuce (Lactuca sativa) can alter the crop productivity and chemical properties of this vegetable, such as the levels of nitrate in the leaves. The present study investigated, based on research inherent to the results of analyzes concerning the nitrate content in conventional, organic and hydroponic lettuces, that yields are within the parameters established by Food and Agriculture Organization of the United Nations (FAO) and World Health Organization (WHO). The research was developed by the inductive-deductive method proposed by Aristotle, making a documentary analysis between the proposed results and the established legal parameters. It was found that the levels found do not violate the principle of legal certainty, according to the theory of fundamental rights that support the right to health and the ecologically balanced environment. Within this context, it was found that the absence of specific legislation in Brazil regarding the maximum levels of nitrate ion allowed in vegetables, does not prevent the realization of fundamental rights to health and to the ecologically balanced environment, not compromising the legal security that involves the consumption relations. Thus, the results suit to guide vegetable producers, as well as to subsidize specific legislation on the subject in Brazil in the future. Keywords: Food Safety. Fundamental Rights. Right to Health. Lactuca Sativa. NO3- Limits.
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van Helmond, Niels A. G. M., Elizabeth K. Robertson, Daniel J. Conley, et al. "Removal of phosphorus and nitrogen in sediments of the eutrophic Stockholm archipelago, Baltic Sea." Biogeosciences 17, no. 10 (2020): 2745–66. http://dx.doi.org/10.5194/bg-17-2745-2020.
Повний текст джерелаАнотація:
Abstract. Coastal systems can act as filters for anthropogenic nutrient input into marine environments. Here, we assess the processes controlling the removal of phosphorus (P) and nitrogen (N) for four sites in the eutrophic Stockholm archipelago. Bottom water concentrations of oxygen (O2) and P are inversely correlated. This is attributed to the seasonal release of P from iron-oxide-bound (Fe-oxide-bound) P in surface sediments and from degrading organic matter. The abundant presence of sulfide in the pore water and its high upward flux towards the sediment surface (∼4 to 8 mmol m−2 d−1), linked to prior deposition of organic-rich sediments in a low-O2 setting (“legacy of hypoxia”), hinder the formation of a larger Fe-oxide-bound P pool in winter. This is most pronounced at sites where water column mixing is naturally relatively low and where low bottom water O2 concentrations prevail in summer. Burial rates of P are high at all sites (0.03–0.3 mol m−2 yr−1), a combined result of high sedimentation rates (0.5 to 3.5 cm yr−1) and high sedimentary P at depth (∼30 to 50 µmol g−1). Sedimentary P is dominated by Fe-bound P and organic P at the sediment surface and by organic P, authigenic Ca-P and detrital P at depth. Apart from one site in the inner archipelago, where a vivianite-type Fe(II)-P mineral is likely present at depth, there is little evidence for sink switching of organic or Fe-oxide-bound P to authigenic P minerals. Denitrification is the major benthic nitrate-reducing process at all sites (0.09 to 1.7 mmol m−2 d−1) with rates decreasing seaward from the inner to outer archipelago. Our results explain how sediments in this eutrophic coastal system can remove P through burial at a relatively high rate, regardless of whether the bottom waters are oxic or (frequently) hypoxic. Our results suggest that benthic N processes undergo annual cycles of removal and recycling in response to hypoxic conditions. Further nutrient load reductions are expected to contribute to the recovery of the eutrophic Stockholm archipelago from hypoxia. Based on the dominant pathways of P and N removal identified in this study, it is expected that the sediments will continue to remove part of the P and N loads.
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Walters, A. H., J. R. Fletcher, and S. J. Law. "Nitrate in Vegetables: Estimation by HPLC." Nutrition and Health 4, no. 3 (1986): 141–49. http://dx.doi.org/10.1177/026010608600400303.
Повний текст джерелаАнотація:
Over the past fifty years the development of high-tech farming has led to excessive amounts of fertiliser being applied to soil. Some research aspects of this abuse are described in relation to the uptake of nitrate into vegetables. In order to monitor this problem a high precision HPLC method capable of rapid throughput has been evolved. Using this HPLC method the results over a twelve month period are presented and compared with the existing standards now legally enforced in Switzerland and Holland.
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Jurburg, Stephanie D., Féline L. Assemien, Léa Beaumelle, Joana F. Salles, Jan Dirk Van Elsas, and Xavier Le Roux. "A history of extreme disturbance affects the relationship between the abundances of nitrifiers in soil." Biology and Fertility of Soils 56, no. 8 (2020): 1177–87. http://dx.doi.org/10.1007/s00374-020-01491-8.
Повний текст джерелаАнотація:
Abstract To understand how and to what extent single or multiple perturbations can alter the relationships between the abundances of different nitrifier groups and nitrification, soil microcosms were exposed to six disturbance treatments: a heat shock, cold shock, or control conditions applied to undisturbed soils or to soils that had previously been subjected to a first heat shock. We monitored the recovery of the abundances of four main nitrifier groups (ammonia-oxidizing archaea and bacteria, AOA and AOB, respectively, and Nitrobacter and Nitrospira nitrite oxidizers) as well as nitrification activity for 25 days. AOA were sensitive to cold shocks, whereas AOB were not; the latter were sensitive to heat shock. Despite the variations, both groups were resilient to the first disturbance. In contrast, Nitrobacter was affected by both disturbances, whereas Nitrospira was resistant to both shocks. Prior exposure to a heat shock affected each group’s responses as well as the relationships between them. For example, AOB were more vulnerable to heat shock in pre-exposed soils, whereas under the same circumstances, AOA were resilient. Nitrification activity was resistant to the first disturbances, but a legacy effect was observed, and nitrification was highest in Heat-Heat and lowest in Heat-Cold treatments. Overall, our study shows that within soil nitrifiers, temporal patterns and legacy effects interact to result in complex disturbance responses.
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De Groef, Bert, Brigitte R. Decallonne, Serge Van der Geyten, Veerle M. Darras, and Roger Bouillon. "Perchlorate versus other environmental sodium/iodide symporter inhibitors: potential thyroid-related health effects." European Journal of Endocrinology 155, no. 1 (2006): 17–25. http://dx.doi.org/10.1530/eje.1.02190.
Повний текст джерелаАнотація:
Objective: Perchlorate is a known competitive inhibitor of the sodium/iodide symporter (NIS). Possible thyroid-related effects of environmental perchlorate have created great health concerns, especially in the US, resulting in a debated reference dose (RfD) of 0.0007 mg/kg per day in drinking water recommended by the National Academy of Sciences (NAS). However, the impact of other environmental NIS inhibitors and the role of iodine seem to have received little attention in the whole debate. Methods: We performed a PubMed search for articles published up to February 2006, using the key terms perchlorate, nitrate, thiocyanate, iodine, NIS, RfD, thyroid (alone or in combinations), with particular attention for human studies. In parallel, we critically analysed the January 2005 NAS’ report, entitled ‘Health implications of perchlorate ingestion’. Results: The relative potencies of prevalent environmental NIS inhibitors (nitrate, thiocyanate and perchlorate) to inhibit iodine uptake have been estimated repeatedly with robust results. Our calculations show that nitrate and thiocyanate, acquired through drinking water or food, account for a much larger proportion of iodine uptake inhibition than perchlorate. Furthermore, the iodine uptake inhibitory effects of nitrate and thiocyanate – as defined by their legally accepted maximal contaminant levels in drinking water – exceed the potential effect of the proposed RfD for perchlorate by far. Conclusions: Iodine uptake inhibition and any potential downstream effect by perchlorate are highly dependent on the presence of other environmental NIS inhibitors and iodine intake itself. These potential confounders should therefore be considered in future studies and calculations for risk assessment.
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Ding, Weixuan, Johannes A. Botha, Bruce C. Hanson, and Ian T. Burke. "Synthesis of Calcium Monouranate Particles via an Aqueous Route." MRS Advances 1, no. 62 (2016): 4123–29. http://dx.doi.org/10.1557/adv.2017.199.
Повний текст джерелаАнотація:
ABSTRACTLarge stores of unstable waste uranic materials such as fluorides or nitrates exist internationally due to legacy civil nuclear enrichment activities. Conversion of these uranic materials to layered metal uranates prior to disposal is possible via aqueous quench - precipitation type reactions. Previous studies1 have shown facile in-situ formation of geologically persistent and labile uranate colloids2 under simulated nuclear waste repository conditions, though the effects of local solution metal-uranium ratios on uranate stoichiometry have yet to be covered. This affects our understanding of how key radionuclides present in repository porewaters such as strontium or caesium may be sequestered in these uranate structures. In this work, we demonstrate a synthesis reaction for calcium monouranate particles via rapid anhydrous curing of a sol-gel. We present some results showing aqueous nucleation of uranate nanoparticles and their phase transformations during thermal curing as well as the effects of solution phase calcium loading on uranate phase purity in the cured particles.
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Sarvesvaran, E. R., R. Fysh, and D. A. L. Bowen. "4. Amyl Nitrite Related Deaths." Medicine, Science and the Law 32, no. 3 (1992): 267–69. http://dx.doi.org/10.1177/002580249203200316.
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Souza, Antonio Donizetti Gonçalves de, and José Galizia Tundisi. "Water quality in watershed of the Jaboatão River (Pernambuco, Brazil): a case study." Brazilian Archives of Biology and Technology 46, no. 4 (2003): 711–21. http://dx.doi.org/10.1590/s1516-89132003000400026.
Повний текст джерелаАнотація:
The purpose of the present work was to evaluate anthropogenic influences on the water quality and to offer a subsidy to the establishment of water quality goals in the Jaboatão River Basin (Pernambuco State, Brazil). Eight sampling points were established and were sampled monthly during one hydrological cycle (March/98-February/99). The following variables were analyzed: temperature, pH, conductivity, chlorine, alkalinity, dissolved oxygen, biochemical oxygen demand, fecal coliforms, nitrate, total phosphorus and total solids. The most critical variables related to water quality objectives were dissolved oxygen, fecal coliforms and total phosphorus. Maps of land use, legally protected areas, area industries, and water withdrawals were utilized in order to propose division of the watershed into regions and to provide water quality management information.
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Schmalz, B., F. Tavares, and N. Fohrer. "Assessment of nutrient entry pathways and dominating hydrological processes in lowland catchments." Advances in Geosciences 11 (June 15, 2007): 107–12. http://dx.doi.org/10.5194/adgeo-11-107-2007.
Повний текст джерелаАнотація:
Abstract. The achievement of a good water quality in all water bodies until 2015 is legally regulated since December 2000 for all European Union member states by the European Water Framework Directive (EU, 2000). The aim of this project is to detect nutrient entry pathways and to assess the dominating hydrological processes in complex mesoscale catchments. The investigated Treene catchment is located in Northern Germany as a part of a lowland area. Sandy, loamy and peat soils are characteristic for this area. Land use is dominated by agriculture and pasture. Drainage changed the natural water balance. In a nested approach we examined two catchment areas: a) Treene catchment 517 km2, b) Kielstau catchment 50 km2. The nested approach assists to improve the process understanding by using data of different scales. Therefore these catchments serve not only as an example but the results are transferable to other lowland catchment areas. In a first step the river basin scale model SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) was used successfully to model the water balance. Furthermore the water quality was analysed to distinguish the impact of point and diffuse sources. The results show that the tributaries in the Kielstau catchment contribute high amounts of nutrients, mainly nitrate and ammonium. For the parameters nitrate, ammonium and phosphorus it was observed as a tendency that the annual loads were increasing along the river profile of the Kielstau.
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Zenatti, Dilcemara C., Simone D. Gomes, Ajadir Fazolo, Ricardo N. Costanzi, Salah D. M. Hasan, and André L. Gentelini. "Nitrificação de efluente de abatedouro de tilápia em função da aeração e tempo de reação." Revista Brasileira de Engenharia Agrícola e Ambiental 13, no. 6 (2009): 750–54. http://dx.doi.org/10.1590/s1415-43662009000600013.
Повний текст джерелаАнотація:
A ocorrência de compostos nitrogenados em água residuária de abatedouro de tilápia acima dos limites legais, tem causado sérios problemas de poluição em corpos d'água receptores. O processo biológico para remoção dessas substâncias comumente encontradas sob a forma de nitrogênio amoniacal, é conhecido como nitrificação. Objetivou-se, com o presente trabalho, estudar o efeito do tempo de reação (TR) e da aeração na eficiência da remoção de nitrogênio amoniacal e na conversão do nitrogênio amoniacal a nitrato, de água residuária de abate de tilápia em um reator em batelada sequencial com biofilme. O experimento foi executado usando-se dois TR(6 e 12 h) e dois níveis de vazão de ar (3 e 6 L min-1); avaliaram-se quatro tratamentos a partir da combinação dessas variáveis configuradas em um planejamento experimental do tipo factorial 2², sendo: T1 (QAr = 3 L min-1 e TR = 6 h); T2 (QAr = 6 L min-1 e TR = 6 h), T3 (QAr = 3 L min-1 e TR = 12 h) e T4 (QAr = 6 L min-1 e TR = 12 h), e quatro repetições para cada tratamento. Os resultados mais significativos foram para o tratamento T4, com o qual se obteve média de eficiência para conversão de amônio a nitrato e remoção de nitrogênio amoniacal de 57,27 ± 27,05% e 81,90 ± 3,80%, respectivamente.
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Simonetti, Giulia, Patrizia Di Filippo, Carmela Riccardi, Donatella Pomata, Elisa Sonego, and Francesca Buiarelli. "Occurrence of Halogenated Pollutants in Domestic and Occupational Indoor Dust." International Journal of Environmental Research and Public Health 17, no. 11 (2020): 3813. http://dx.doi.org/10.3390/ijerph17113813.
Повний текст джерелаАнотація:
The occurrence of halogenated organic pollutants in indoor dust can be high due to the presence of textile, electronic devices, furniture, and building materials treated with these chemicals. In this explorative study, we focused on emerging organic pollutants, such as novel brominated flame retardants (nBFRs) and some perfluoroalkyl substances, together with legacy polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (BDEs) in settled dust collected in houses and workplaces such as one office and two electrotechnical and mechanical workshops. The total contribution of the investigated pollutants was lower in house and in office dusts except for few nBFRs (such as bis (2-ethylhexyl)-3,4,5,6-tetrabromo-phthalate at a concentration of 464.5 ng/g in a house and hexachlorocyclopentadienyldibromocyclooctane at 40.4 ng/g in the office), whereas in electrotechnical and mechanical workshops a high incidence of PCBs, BDEs, and nBFRs occurred (for example, BDE 209 at a concentration of 2368.0 ng/g and tetrabromobisphenol A at 32,320.1 ng/g in electrotechnical and mechanical workshops). Estimated daily intakes were also calculated, showing that domestic and occupational environments can lead to a similar contribution in terms of human exposure. The higher exposure contribution was associated to nBFRs, whose EDIs were in the range of 3968.2–555,694.2 pg/kg bw/day. To provide a complete view about the indoor contamination, in this investigation, we also included polycyclic aromatic hydrocarbons (PAHs) and their oxygenated and nitrated derivatives. Definitely, dust collection represents a simple, fast, and cost-effective sampling and dust contamination level can be a useful indicator of environment healthiness. Besides, the presented method can be a smart tool to provide a time and money saving technique to characterize 99 pollutants thanks to a single sample treatment.
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Dias, Pollyanna Aparecida, Fernanda Barbosa Lupki, Chrystiellen Ayana Aparecida Rodrigues, Mauro Ramalho Silva, Ana Catarina Perez Dias, and Harriman Aley Morais. "Características Físico-Químicas de Patês de Frango Light em Sódio." Ensaios e Ciência C Biológicas Agrárias e da Saúde 24, no. 1 (2020): 75–81. http://dx.doi.org/10.17921/1415-6938.2020v24n1p65-74.
Повний текст джерелаАнотація:
A redução de cloreto (NaCl) e/ou de nitrito de sódio (NaNO2) é uma relevante estratégia a ser implementada pela indústria, considerando os problemas de saúde relacionados ao consumo excessivo de sódio. Substituições parciais desses sais por concentrado proteico de soro de leite (WPC), um subproduto da indústria láctea, é uma alternativa a ser investigada visando manter as propriedades tecnológicas dos produtos. Objetivou-se produzir e avaliar a qualidade físico-química de patê de frango com teores reduzidos destes sais, e adicionados de WPC. Elaboraram-se quatro formulações com concentrações variadas dos ingredientes, distribuídos em um delineamento em blocos casualizados com três repetições e em triplicata: P1 - controle (1,3% de NaCl e 0,5% de NaNO2); P2 (0,25% de NaNO2e 0,25% de WPC), P3 (0,65% de NaCl e 0,65% de WPC) e P4 (0,25% de NaNO2, 0,65% de NaCl e 0,9% de WPC). Procedeu-se a caracterização físico-química da massa crua (composição química, teor de proteínas sal-solúveis, estabilidade da emulsão, pH e cor). Os dados obtidos foram submetidos a análise de variância e teste de média por Tukey (p< 0,05). Todas as formulações atenderam aos requisitos legais quanto aos teores de proteínas, de lipídeos e de umidade. As amostras com maiores quantidades de WPC (P3 e P4) apresentaram maior estabilidade da emulsão em relação ao controle (P1). Concluiu-se que foi possível elaborar patê de frango com teores de cloreto e nitrito de sódio reduzidos, obtendo-se produtos com apelos mais saudáveis.
 Palavras-chave: Cloreto de Sódio. Nitrito de Sódio. Proteínas Lácteas. Produto Cárneo. Aditivos Alimentares.
 
 Abstract
 Salt (NaCl) and sodium nitrite (NaNO2) are important ingredients in food production, due to technological properties. However, the reduction of these salts is relevant strategy to be implemented by the food industry, being its replacements by whey protein concentrate (WPC), a byproduct of the dairy industry, an alternative to be investigated. In this study, the physicochemical quality of chicken pate with low levels of salts and with addition of WPC was produced and evaluated. Four formulations were prepared with the same ingredients varying only the NaCl and NaNO2 concentrations, namely: P1 - control (1.3% NaCl and 0.5% NaNO2); P2 (0.25% NaNO2 and 0.25% WPC), P3 (0.65% NaCl and 0.65% WPC) and P4 (0.25% NaNO2, 0.65 % NaCl and 0.9% WPC). The physicochemical characterization of the raw batter (chemical composition, in salt-soluble proteins, emulsion stability, pH and color) of the chicken patês were performed. The analysis of variance, in a randomized complete block design, was performed for investigating the significant effects among the treatments (p < 0.05), with Tukey test. Regarding the raw batter, the pâté had the legal requirements for the content of proteins, lipids and moisture. Furthermore, the WPC incorporation increased emulsion stability in some samples (P3 and P4) compared to the control. It was concluded that it was possible to prepare chicken patê with low chloride and sodium nitrite levels, thus obtaining healthier products
 Keywords: Chloride Sodium. Sodium Nitrite. Milk Proteins. Meat Product. Food Additive.
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Johnson, H. M., and E. G. Stets. "Nitrate in Streams During Winter Low‐Flow Conditions as an Indicator of Legacy Nitrate." Water Resources Research 56, no. 11 (2020). http://dx.doi.org/10.1029/2019wr026996.
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Vázquez-Campos, Xabier, Andrew S. Kinsela, Mark W. Bligh, Timothy E. Payne, Marc R. Wilkins, and T. David Waite. "Genomic Insights Into the Archaea Inhabiting an Australian Radioactive Legacy Site." Frontiers in Microbiology 12 (October 18, 2021). http://dx.doi.org/10.3389/fmicb.2021.732575.
Повний текст джерелаАнотація:
During the 1960s, small quantities of radioactive materials were co-disposed with chemical waste at the Little Forest Legacy Site (LFLS, Sydney, Australia). The microbial function and population dynamics in a waste trench during a rainfall event have been previously investigated revealing a broad abundance of candidate and potentially undescribed taxa in this iron-rich, radionuclide-contaminated environment. Applying genome-based metagenomic methods, we recovered 37 refined archaeal MAGs, mainly from undescribed DPANN Archaea lineages without standing in nomenclature and ‘Candidatus Methanoperedenaceae’ (ANME-2D). Within the undescribed DPANN, the newly proposed orders ‘Ca. Gugararchaeales’, ‘Ca. Burarchaeales’ and ‘Ca. Anstonellales’, constitute distinct lineages with a more comprehensive central metabolism and anabolic capabilities within the ‘Ca. Micrarchaeota’ phylum compared to most other DPANN. The analysis of new and extant ‘Ca. Methanoperedens spp.’ MAGs suggests metal ions as the ancestral electron acceptors during the anaerobic oxidation of methane while the respiration of nitrate/nitrite via molybdopterin oxidoreductases would have been a secondary acquisition. The presence of genes for the biosynthesis of polyhydroxyalkanoates in most ‘Ca. Methanoperedens’ also appears to be a widespread characteristic of the genus for carbon accumulation. This work expands our knowledge about the roles of the Archaea at the LFLS, especially, DPANN Archaea and ‘Ca. Methanoperedens’, while exploring their diversity, uniqueness, potential role in elemental cycling, and evolutionary history.
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Kim, Seok Hee, Ho-Rim Kim, Soonyoung Yu, et al. "Shift of nitrate sources in groundwater due to intensive livestock farming on Jeju Island, South Korea: with emphasis on legacy effects on water management." Water Research, January 2021, 116814. http://dx.doi.org/10.1016/j.watres.2021.116814.
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Domingos, Ana Carolina Gomes, Guilherme Ferraz Rodrigues, Adriano França Da Cunha, et al. "QUALIDADE FÍSICO-QUÍMICA E MICROBIOLÓGICA DE BEBIDAS LÁCTEAS UAT COMERCIALIZADAS EM VIÇOSA-MG." Archives of Veterinary Science 15, no. 5 (2020). http://dx.doi.org/10.5380/avs.v15i5.76393.
Повний текст джерелаАнотація:
A bebida láctea é obtida da mistura de leite e soro de leite, fermentada ou não, e que pode comprometer a saúde do consumidor. Além disto, há risco de serem produzidas com soro contendo nitrato e nitrito devido a utilização de tais conservantes na fabricação de queijos. Portanto, o objetivo do trabalho foi avaliar a qualidade microbiológica e físico-química em quatro marcas de bebidas lácteas UAT comercializadas na cidade de Viçosa (MG). Cinco lotes de cada marca foram avaliados quanto à contagem de mesófilos, coliformes totais e termotolerantes, fungos, Staphylococcus spp., pesquisa de Salmonella spp. e quanto aos teores de proteína e gordura de acordo com metodologias do Ministério da Agricultura, Pecuária e Abastecimento (MAPA). Os teores de nitrato e nitrito foram determinados de acordo com metodologia adaptada do MAPA para bebidas lácteas. Os resultados foram analisados de forma descritiva de acordo com os parâmetros legais estabelecidos pela legislação brasileira. Nenhuma amostra apresentou contagem de mesófilos, coliformes, fungos, Salmonella spp. e Staphylococcus spp., o que sugere que há controle de contaminação industrial e qualidade da matéria prima. Além disso, os produtos não foram violados durante o transporte e armazenamento, tanto na indústria quanto nos supermercados. Uma (5%) e 16 (80%) amostras apresentaram teores de proteína e gordura abaixo dos limites mínimos de 1g/100g e 2g/100g, respectivamente. Alterações nos teores sólidos se devem às variadas técnicas de processamento, uso de leite e soro de diferentes composições e à proporção de ingredientes não lácteos adicionados. Nenhuma amostra apresentou resultado positivo na prova de nitrito ou nitrato, o que sugere que as indústrias possuem controle de produção e qualidade do soro quanto à presença de tais conservantes. Portanto, bebidas lácteas de Viçosa (MG) possuem boa qualidade microbiológica e não apresentam nitrato e nitrito. Entretanto, as marcas avaliadas apresentam teores de gordura e proteína em desconformidade com a legislação.
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"ECOLOGICAL POLICY OF EU COUNTRIES REGARDING THE REGULATION OF PUBLIC RELATIONS IN THE FIELD OF MAINTAINING ENVIRONMENTAL SAFETY." Journal of V. N. Karazin Kharkiv National University, Series "Law", no. 30 (2020). http://dx.doi.org/10.26565/2075-1834-2020-30-17.
Повний текст джерелаАнотація:
Introduction. The article is devoted to the analysis of the environmental policy of the EU countries on the regulation of public relations in the field of environmental safety. The article clarifies the legislative definition of environmental safety in Ukraine. It was found that the indicator that comprehensively reflects various aspects of the environment, the sustainability of ecological systems, as well as the effectiveness of state policy in the field of ecology is the index of environmental efficiency. The index of ecological efficiency in the context of the countries of the European Union is analyzed. The author calculates the dynamics of changes in the environmental performance index for EU countries. The division of EU countries by regions has been carried out. Summary of the main research results. The environmental legislation of the EU countries, in particular, Denmark, Slovakia, France and Malta, which have the highest indicators of the environmental efficiency index for 2018 in their region, is analyzed. The place of Ukraine in the specified rating is defined. It is determined that the environmental efficiency index for 2020 is calculated according to the new methodology, so it can no longer be used in retrospect.It is found that maintaining environmental safety is a complex concept that encompasses a wide range of measures, procedures and practices to maintain environmental safety and human security at the proper level of their existence, in order to protect them from anthropogenic impacts and natural changes. Conclusions. It is concluded that for the most part the structure and content of environmental legislation of the EU is similar to the Ukrainian, both in terms of specialization of laws and government agencies that ensure compliance with regulations. However, the low efficiency of our public services is still linked to the Soviet legacy (as in Slovakia). The need for a more detailed analysis and outline of prospects for the implementation of the Danish experience in Ukraine on the regulation of land relations, rules for the use of fertilizers, implementation of programs for the use of nitrates, opportunities for benefits for farmers. It is determined that the main leitmotif of EU environmental policies is the greening of the economy and large-scale use of renewable energy sources. Emphasis is placed on the urgent need for a comprehensive policy of environmental education of Ukrainian citizens, starting from school age.