Occurrence of perchlorate in groundwater, paired farmland soil, lettuce, and rhizosphere soil from Chengdu, China.

Science.gov (United States)

Tang, Yulu; Zhong, Bifeng; Qu, Bing; Feng, Shujin; Ding, Sanglan; Su, Shijun; Li, Zhi; Gan, Zhiwei

2017-05-24

A total of 28 groundwater, paired farmland soil, lettuce, and its rhizosphere soil samples were collected from Chengdu, China to detect perchlorate levels and to evaluate the relationships of perchlorate concentrations among these matrices. The perchlorate concentrations in the groundwater, farmland soil, lettuce, and rhizosphere soil samples ranged from below detection limit to 60.2 μg L -1 , from below detection limit to 249 μg kg -1 dry weight (dw), from 2.07 to 1010 μg kg -1 wet weight, and from below detection limit to 314 μg kg -1 dw, respectively. Significant correlation was found in the perchlorate levels among the farmland soil, lettuce, and rhizosphere soil, suggesting that they have common pollution sources, or perchlorate might transfer from farmland soil-rhizosphere soil-plant. However, there is no significant correlation between groundwater and the other three matrices, indicating that infiltration from perchlorate contaminated farmland soil was not the predominant source for groundwater pollution in Chengdu. The perchlorate concentrations in the farmland soil and lettuce samples were significantly higher than those in the rhizosphere soil, primarily due to uptake of perchlorate through the rhizosphere micro-environment by lettuce, or accelerated degradation by rhizospheric microorganisms, which contributed more needs further investigation.

Stable isotope probing reveals the importance of Comamonas and Pseudomonadaceae in RDX degradation in samples from a Navy detonation site.

Science.gov (United States)

Jayamani, Indumathy; Cupples, Alison M

2015-07-01

This study investigated the microorganisms involved in hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) degradation from a detonation area at a Navy base. Using Illumina sequencing, microbial communities were compared between the initial sample, samples following RDX degradation, and controls not amended with RDX to determine which phylotypes increased in abundance following RDX degradation. The effect of glucose on these communities was also examined. In addition, stable isotope probing (SIP) using labeled ((13)C3, (15)N3-ring) RDX was performed. Illumina sequencing revealed that several phylotypes were more abundant following RDX degradation compared to the initial soil and the no-RDX controls. For the glucose-amended samples, this trend was strong for an unclassified Pseudomonadaceae phylotype and for Comamonas. Without glucose, Acinetobacter exhibited the greatest increase following RDX degradation compared to the initial soil and no-RDX controls. Rhodococcus, a known RDX degrader, also increased in abundance following RDX degradation. For the SIP study, unclassified Pseudomonadaceae was the most abundant phylotype in the heavy fractions in both the presence and absence of glucose. In the glucose-amended heavy fractions, the 16S ribosomal RNA (rRNA) genes of Comamonas and Anaeromxyobacter were also present. Without glucose, the heavy fractions also contained the 16S rRNA genes of Azohydromonas and Rhodococcus. However, all four phylotypes were present at a much lower level compared to unclassified Pseudomonadaceae. Overall, these data indicate that unclassified Pseudomonadaceae was primarily responsible for label uptake in both treatments. This study indicates, for the first time, the importance of Comamonas for RDX removal.

Water quality criteria for hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)

Energy Technology Data Exchange (ETDEWEB)

Etnier, E.L.

1989-04-01

The occurrence of the munitions compound hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in groundwater surrounding Army ammunition plants may result in contamination of local drinking water supplies. RDX exerts its primary toxic effect in humans on the central nervous system, but also involves gastrointestinal and renal effects. Symptomatic effects following acute exposure include hyperirritability, nausea, vomiting, generalized epileptiform seizures, and prolonged postictal confusion and amnesia. Health effects data were analyzed for RDX, and although no controlled human studies exist concerning the acute or chronic toxic effects of exposure to RDX, sufficient animal toxicity data are available to derive an ambient water quality criterion for the protection of human health. This paper summarizes the available literature on metabolism of RDX and human and animal toxicity. Based on noncarcinogenic mammalian toxicity data, and following the methodologies of the U.S. Environmental Protection Agency, an ambient water quality criterion for the protection of human health of 103 micrograms/liter is proposed for ingestion of drinking water and aquatic foodstuffs. A criterion of 105 micrograms/liter is proposed for ingestion of drinking water alone.54 references.

The effect of tributyltin-oxide on earthworms, springtails, and plants in artificial and natural soils.

Science.gov (United States)

Römbke, J; Jänsch, S; Junker, T; Pohl, B; Scheffczyk, A; Schallnass, H-J

2007-05-01

Chemical bioavailability in Organisation for Economic Co-operation and Development (OECD) artificial soil can contrast with bioavailability in natural soils and produce ecotoxicologic benchmarks that are not representative of species' exposure conditions in the field. Initially, reproduction and growth of earthworm and Collembolan species, and early seedling growth of a dicotyledonous plant species, in nine natural soils (with a wide range of physicochemical properties) and in OECD soil were evaluated. Soils that supported reproduction and growth of the test species were then used to investigate the toxicity of tributyltin-oxide (TBT-O). Natural soils caused greater toxicity of TBT-O to earthworms (EC(50) values varied from 0.5 to 4.7 mg/kg soil dry weight [dw]) compared with toxicity in OECD soil (EC(50) = 13.4 mg/kg dw). Collembolans were less sensitive to TBT-O than earthworms in natural soils, with EC(50) values ranging from 23.4 to 177.8 mg/kg dw. In contrast, the toxicity of TBT-O to collembolans in OECD soil (EC(50) = 104.0 mg/kg dw) was within the range of EC(50) values in natural soils. Phytotoxicity tests revealed even greater difference between the effects in natural soils (EC(50) values ranged from 10.7 to 189.2 mg/kg dw) and in OECD soil (EC(50) = 535.5 mg/kg dw) compared with results of the earthworm tests. Studies also showed that EC(50) values were a more robust end point compared with EC(10) values based on comparisons of coefficients of variation. These results show that toxicity testing should include studies with natural soils in addition to OECD soil to better reflect exposure conditions in the field.

Morphological and functional responses of a metal-tolerant sunflower mutant line to a copper-contaminated soil series.

Science.gov (United States)

Kolbas, Aliaksandr; Kolbas, Natallia; Marchand, Lilian; Herzig, Rolf; Mench, Michel

2018-04-02

The potential use of a metal-tolerant sunflower mutant line for biomonitoring Cu phytoavailability, Cu-induced soil phytotoxicity, and Cu phytoextraction was assessed on a Cu-contaminated soil series (13-1020 mg Cu kg -1 ) obtained by fading a sandy topsoil from a wood preservation site with a similar uncontaminated soil. Morphological and functional plant responses as well as shoot, leaf, and root ionomes were measured after a 1-month pot experiment. Hypocotyl length, shoot and root dry weight (DW) yields, and leaf area gradually decreased as soil Cu exposure rose. Their dose-response curves (DRC) plotted against indicators of Cu exposure were generally well fitted by sigmoidal curves. The half-maximal effective concentration (EC 50 ) of morphological parameters ranged between 203 and 333 mg Cu kg -1 soil, corresponding to 290-430 μg Cu L -1 in the soil pore water, and 20 ± 5 mg Cu kg -1 DW in the shoots. The EC 10 for shoot Cu concentration (13-15 mg Cu kg -1 DW) coincided to 166 mg Cu kg -1 soil. Total chlorophyll content and total antioxidant capacity (TAC) were early biomarkers (EC 10 : 23 and 51 mg Cu kg -1 soil). Their DRC displayed a biphasic response. Photosynthetic pigment contents, e.g., carotenoids, correlated with TAC. Ionome was changed in Cu-stressed roots, shoots, and leaves. Shoot Cu removal peaked roughly at 280 μg Cu L -1 in the soil pore water.

Effects of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in zebrafish: General and reproductive toxicity

Science.gov (United States)

Mukhi, S.; Patino, R.

2008-01-01

Mixed-sex populations of young adult zebrafish (???2-month-old) were exposed to measured RDX concentrations of 0, 1 or 9.6 ppm for up to 12 weeks followed by a 15-day rearing period in untreated water. RDX caused high mortality at 9.6 ppm, with most deaths occurring within the first 8 weeks of exposure. RDX at 9.6 ppm caused lower body weights at 4 and 8 weeks of exposure; and at 1 ppm, lower body weight was observed only at 4 weeks. Fish length was not affected by treatment at any time during the exposure period. The bioconcentration factor for RDX seemed to be influenced by time of exposure but not by water RDX concentration; its overall values were 1.01 ?? 0.13, 0.91 ?? 0.06 and 2.23 ?? 0.04 at 4, 8 weeks and 12 weeks, respectively. RDX was not detected in fish collected after the 15-day recovery period. In a separate experiment, adult females and males were separately exposed to RDX at measured concentrations of 0, 0.5 and 3.2 ppm for a period of 6 weeks. Reproductive performance was evaluated by biweekly breeding of the fish and measuring packed-egg volume (PEV) as index of fecundity. At 0.5 ppm, RDX caused elevated PEV levels relative to the control value at 2 weeks but not at 4 or 6 weeks, whereas no significant effects were noted at 3.2 ppm. Egg fertilization and embryo hatching rates were not affected by RDX at any of the concentrations tested. In conclusion, RDX at sublethal concentrations causes short-term negative effects on growth and, at 0.5 ppm, positive effects on fecundity. ?? 2008 Elsevier Ltd.

Nitrogen transformations and greenhouse gas emissions from a riparian wetland soil: An undisturbed soil column study

Energy Technology Data Exchange (ETDEWEB)

Munoz-Leoz, Borja [Department of Chemical and Environmental Engineering, University of the Basque Country, UPV/EHU, E-48013 Bilbao (Spain); Antigueedad, Inaki [Department of Geodynamic, University of the Basque Country, UPV/EHU, E-48940 Leioa (Spain); Garbisu, Carlos [Department of Ecosystems, NEIKER-Tecnalia, E-48160 Derio (Spain); Ruiz-Romera, Estilita, E-mail: estilita.ruiz@ehu.es [Department of Chemical and Environmental Engineering, University of the Basque Country, UPV/EHU, E-48013 Bilbao (Spain)

2011-01-15

Riparian wetlands bordering intensively managed agricultural fields can act as biological filters that retain and transform agrochemicals such as nitrate and pesticides. Nitrate removal in wetlands has usually been attributed to denitrification processes which in turn imply the production of greenhouse gases (CO{sub 2} and N{sub 2}O). Denitrification processes were studied in the Salburua wetland (northern Spain) by using undisturbed soil columns which were subsequently divided into three sections corresponding to A-, Bg- and B2g-soil horizons. Soil horizons were subjected to leaching with a 200 mg NO{sub 3}{sup -} L{sup -1} solution (rate: 90 mL day{sup -1}) for 125 days at two different temperatures (10 and 20 {sup o}C), using a new experimental design for leaching assays which enabled not only to evaluate leachate composition but also to measure gas emissions during the leaching process. Column leachate samples were analyzed for NO{sub 3}{sup -} concentration, NH{sub 4}{sup +} concentration, and dissolved organic carbon. Emissions of greenhouse gases (CO{sub 2} and N{sub 2}O) were determined in the undisturbed soil columns. The A horizon at 20 {sup o}C showed the highest rates of NO{sub 3}{sup -} removal (1.56 mg N-NO{sub 3}{sup -} kg{sup -1} DW soil day{sup -1}) and CO{sub 2} and N{sub 2}O production (5.89 mg CO{sub 2} kg{sup -1} DW soil day{sup -1} and 55.71 {mu}g N-N{sub 2}O kg{sup -1} DW soil day{sup -1}). For the Salburua wetland riparian soil, we estimated a potential nitrate removal capacity of 1012 kg N-NO{sub 3}{sup -} ha{sup -1} year{sup -1}, and potential greenhouse gas emissions of 5620 kg CO{sub 2} ha{sup -1} year{sup -1} and 240 kg N-N{sub 2}O ha{sup -1} year{sup -1}. - Research Highlights: {yields}A new experimental design is proposed for leaching assays to simulate nitrogen transformations in riparian wetland soil. {yields}Denitrification is the main process responsible for nitrate removal in the riparian zone of Salburua wetland. {yields

Interactive effects of Cd and PAHs on contaminants removal from co-contaminated soil planted with hyperaccumulator plant Sedum alfredii

Energy Technology Data Exchange (ETDEWEB)

Wang, Kai; Huang, Huagang; Li, Tingqiang; Yang, Xiaoe [Zhejiang Univ., Hangzhou (China). MOE Key Lab. of Environment Remediation and Ecosystem Health; Zhu, Zhiqiang [Zhejiang Univ., Hangzhou (China). MOE Key Lab. of Environment Remediation and Ecosystem Health; Hainan Univ., Haikou (China). College of Agriculture; He, Zhenli [Florida Univ., Port Pierce, FL (United States). Inst. of Food and Agricultural Sciences; Alva, Ashok [US Department of Agriculture, Prosser, WA (United States). Agricultural Research Service

2012-04-15

Purpose: Soil contamination by multiple organic and inorganic contaminants is common but its remediation by hyperaccumulator plants is rarely reported. The growth of a cadmium (Cd) hyperaccumulator Sedum alfredii and removal of contaminants from Cd and polycyclic aromatic hydrocarbons (PAHs) co-contaminated soil were reported in this study. Materials and methods: Soil slightly contaminated by Cd (0.92 mg kg{sup -1} DW) was collected from a vegetable field in Hangzhou and was spiked with two levels (0 and 6 mg kg{sup -1} DW) of Cd and three levels (0, 25, and 150 mg kg{sup -1} DW) of phenanthrene (PHE) or pyrene (PYR). A pot experiment was conducted in a greenhouse using S. alfredii with unplanted controls for 60 days. Shoot and root biomass of plants, dehydrogenase activity (DHA), and microbial biomass carbon in the soil were measured. Concentrations of Cd and PAHs in the plant and soil were determined. Results and discussion: Elevated Cd level (6.38 mg kg{sup -1} DW) increased S. alfredii growth. The presence of PAHs decreased the stimulatory effects of Cd on plant biomass and Cd concentrations in shoots in Cd spiked soil, thus decreasing Cd phytoextraction efficiency. Cadmium removal by S. alfredii after 60 days of growth varied from 5.8% to 6.7% and from 5.7% to 9.6%, in Cd unspiked and spiked soils, respectively. Removal rate of PAHs in the soil was similar with or without the plants. Removal rate of PYR decreased at the elevated Cd level in the soil. This appears to be due to a decrease in soil microbial activity. This is confirmed by a decrease in DHA, which is a good indicator of soil microbial activity. Conclusions: Our results demonstrate that S. alfredii could effectively extract Cd from Cd-contaminated soils in the presence of PHE or PYR; however, both PAHs exhibited negative effects on phytoextraction of Cd from Cd spiked soil (6.38 mg kg{sup -1} DW). S. alfredii is not suitable for remediation of PAHs. The effects of Cd and PAHs concentrations on the

Removal of trichloroethylene (TCE) contaminated soil using a two-stage anaerobic-aerobic composting technique.

Science.gov (United States)

Ponza, Supat; Parkpian, Preeda; Polprasert, Chongrak; Shrestha, Rajendra P; Jugsujinda, Aroon

2010-01-01

The effect of organic carbon addition on remediation of trichloroethylene (TCE) contaminated clay soil was investigated using a two stage anaerobic-aerobic composting system. TCE removal rate and processes involved were determined. Uncontaminated clay soil was treated with composting materials (dried cow manure, rice husk and cane molasses) to represent carbon based treatments (5%, 10% and 20% OC). All treatments were spiked with TCE at 1,000 mg TCE/kg DW and incubated under anaerobic and mesophillic condition (35 degrees C) for 8 weeks followed by continuous aerobic condition for another 6 weeks. TCE dissipation, its metabolites and biogas composition were measured throughout the experimental period. Results show that TCE degradation depended upon the amount of organic carbon (OC) contained within the composting treatments/matrices. The highest TCE removal percentage (97%) and rate (75.06 micro Mole/kg DW/day) were obtained from a treatment of 10% OC composting matrices as compared to 87% and 27.75 micro Mole/kg DW/day for 20% OC, and 83% and 38.08 micro Mole/kg DW/day for soil control treatment. TCE removal rate was first order reaction kinetics. Highest degradation rate constant (k(1) = 0.035 day(- 1)) was also obtained from the 10% OC treatment, followed by 20% OC (k(1) = 0.026 day(- 1)) and 5% OC or soil control treatment (k(1) = 0.023 day(- 1)). The half-life was 20, 27 and 30 days, respectively. The overall results suggest that sequential two stages anaerobic-aerobic composting technique has potential for remediation of TCE in heavy texture soil, providing that easily biodegradable source of organic carbon is present.

Spectrophotometric determination of cyclotrimethylenetrinitramine (RDX) in explosive mixtures and residues with the Berthelot reaction.

Science.gov (United States)

Uzer, A; Erçağ, E; Apak, R

2008-03-31

On-site colorimetric methods are a valuable, cost-effective tool to assess the nature and extent of contamination in remediated sites and to enable on-site screening for police criminology laboratories. The existing colorimetric method for cyclotrimethylenetrinitramine (RDX) based on a Griess reaction suffers from the non-quantitative reduction to nitrite and from the unstable character of HNO2 in acidic medium. Thus we propose a novel spectrophotometric RDX assay in explosive mixtures and residues, based on (Zn+HCl) reduction of RDX in a microwave oven, followed by neutralization of the reduction products to ammonia and low molecular-weight amines, and Berthelot reaction of these amine-compounds with phenol and hypochlorite in alkaline medium to give an intensely blue indophenol dye absorbing at 631nm. The molar absorptivity and limit of detection (LOD) for RDX were (1.08+/-0.04)x10(4) L mol(-1) cm(-1) and 0.18 mg L(-1), respectively. Application of the method to synthetic mixture solutions of RDX and trinitrotoluene (TNT) at varying proportions showed that there was minimal interference from TNT (which could be compensated for by dicyclohexylamine colorimetry), since the Berthelot reaction was essentially non-responsive to m-substituted anilines derived from TNT upon (Zn+HCl) reduction. The proposed method was successfully applied to military-purpose explosive mixtures of (RDX+inert matter) such as Comp A5, Comp C4, and Hexal P30, and to (RDX+TNT) mixtures such as Comp B. The molar absorptivity of RDX was much higher than that of either ammonium or nitrate; RDX could be effectively separated from ammonium and nitrate in soil mixtures, based on solubility differences. The Berthelot method for RDX was statistically validated using Comp B mixtures against standard HPLC equipped with a Hypersil C-18 column with (40% MeOH-60% H2O) mobile phase, and against gas chromatography-thermal energy analysis (GC-TEA) system.

Functional Specification and Architecture of ROBACC DW, V1.0

DEFF Research Database (Denmark)

Pedersen, Torben Bach; Thomsen, Christian

This document covers the functionality and architecture of the data warehouse (named ROBACC DW) developed in the EIAO project. Thus, the document provides descriptions of what can be done with ROBACC DW functionality as well as descriptions of how the system is built. The ROBACC DW is an integral...... part of the prototype demonstrator supporting UWEM produced by the WAB cluster. It should be noted that this is the first version of this document. In this version focus is on release 1 of ROBACC DW although expected functionality of later releases of the data warehouse is also described....... The descriptions for the following releases are, however, less detailed. Later, new revisions of this document describing releases 2 and 3 of the data warehouse will follow....

Preparation and characterization of GA/RDX nanostructured ...

Indian Academy of Sciences (India)

Thenhexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was added and trapped in the nano-porous three-dimensional networks of GA to obtain a novel GA/RDX nanostructured energetic composite. The composition, morphology andstructure of the obtained GA/RDX nanostructured energetic composite were characterized by ...

Sorption of cesium in young till soils

Energy Technology Data Exchange (ETDEWEB)

Lusa, Merja; Lempinen, Janne; Ahola, Hanna; Soederlund, Mervi; Lehto, Jukka [Helsinki Univ. (Finland). Laboratory of Radiochemistry; Lahdenperae, Anne-Maj [Saanio and Riekkola Oy, Consulting Engineers, Helsinki (Finland); Ikonen, Ari T.K. [Posiva Oy, Eurajoki (Finland)

2014-10-01

Soil samples from three forest soil pits were examined down to a depth of approximately three metres using 1 M ammonium acetate extraction and microwave-assisted extraction with concentrated nitric acid (HNO{sub 3}), to study the binding of cesium (Cs) at Olkiluoto Island, southern Finland. Ammonium acetate was used to extract the readily exchangeable Cs fractions roughly representing the Cs fraction in soil which is available for plants. Microwave-assisted HNO{sub 3} extraction dissolves various minerals, e.g. carbonates, most sulphides, arsenides, selenides, phosphates, molybdates, sulphates, iron (Fe) and manganese (Mn) oxides and some silicates (olivine, biotite, zeolite), and reflects the total Cs concentrations. Cs was mostly found in the strongly bound fraction obtained through HNO{sub 3} extraction. The average Cs concentrations found in this fraction were 3.53 ± 0.30 mg/kg (d.w.), 3.06 ± 1.86 mg/kg (d.w.) and 1.83 ± 0.42 mg/kg (d.w.) in the three soil pits, respectively. The average exchangeable Cs found in the ammonium acetate extraction in all three sampling pits was 0.015 ± 0.008 mg/kg (d.w.). In addition, Cs concentrations in the soil solution were determined and in situ distribution coefficients (K{sub d}) for Cs were calculated. Furthermore, the in situ K{sub d} data was compared with the Cs K{sub d} data obtained using the model batch experiments. The in situ K{sub d} values were observed to fairly well follow the trend of batch sorption data with respect to soil depth, but on average the batch distribution coefficients were almost an order of magnitude higher than the in situ K{sub d} data. In situ Cs sorption data could be satisfactory fitted with the Langmuir sorption isotherm, but the Freundlich isotherm failed to fit the data. Finally, distribution coefficients were calculated by an ion exchange approach using soil solution data, the cation exchange capacity (CEC) as well as Cs to sodium (Na) and Cs to potassium (K) ion exchange selectivity

Biogeochemistry of uranium in the soil-plant and water-plant systems in an old uranium mine

International Nuclear Information System (INIS)

Favas, Paulo J.C.; Pratas, João; Mitra, Soumita; Sarkar, Santosh Kumar; Venkatachalam, Perumal

2016-01-01

The present study highlights the uranium (U) concentrations in water–soil–plant matrices and the efficiency considering a heterogeneous assemblage of terrestrial and aquatic native plant species to act as the biomonitor and phytoremediator for environmental U-contamination in the Sevilha mine (uraniferous region of Beiras, Central Portugal). A total of 53 plant species belonging to 22 families was collected from 24 study sites along with ambient soil and/or water samples. The concentration of U showed wide range of variations in the ambient medium: 7.5 to 557 mg kg"− "1 for soil and 0.4 to 113 μg L"− "1 for water. The maximum potential of U accumulation was recorded in roots of the following terrestrial plants: Juncus squarrosus (450 mg kg"− "1 DW), Carlina corymbosa (181 mg kg"− "1 DW) and Juncus bufonius (39.9 mg kg"− "1 DW), followed by the aquatic macrophytes, namely Callitriche stagnalis (55.6 mg kg"− "1 DW) Lemna minor (53.0 mg kg"− "1 DW) and Riccia fluitans (50.6 mg kg"− "1 DW). Accumulation of U in plant tissues exhibited the following decreasing trend: root > leaves > stem > flowers/fruits and this confirms the unique efficiency of roots in accumulating this radionuclide from host soil/sediment (phytostabilization). Overall, the accumulation pattern in the studied aquatic plants (L. minor, R. fluitans, C. stagnalis and Lythrum portula) dominated over most of the terrestrial counterpart. Among terrestrial plants, the higher mean bioconcentration factor (≈ 1 in roots/rhizomes of C. corymbosa and J. squarrosus) and translocation factor (31 in Andryala integrifolia) were encountered in the representing families Asteraceae and Juncaceae. Hence, these terrestrial plants can be treated as the promising candidates for the development of the phytostabilization or phytoextraction methodologies based on the accumulation, abundance and biomass production. - Highlights: • The uranium (U) accumulation efficiency of terrestrial and aquatic

Biogeochemistry of uranium in the soil-plant and water-plant systems in an old uranium mine

Energy Technology Data Exchange (ETDEWEB)

Favas, Paulo J.C., E-mail: pjcf@utad.pt [University of Trás-os-Montes e Alto Douro, UTAD, School of Life Sciences and the Environment, Quinta de Prados, 5000-801 Vila Real (Portugal); MARE, Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); Pratas, João [MARE, Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); University of Coimbra, Faculty of Sciences and Technology, Department of Earth Sciences, 3001-401 Coimbra (Portugal); Instituto de Geologia e Petróleo de Timor Leste, Timor-Leste (Country Unknown); Mitra, Soumita; Sarkar, Santosh Kumar [University of Calcutta, Department of Marine Science, 35, Ballygunge Circular Road, Calcutta 700019, West Bengal (India); Venkatachalam, Perumal [Periyar University, Department of Biotechnology, Salem 636 011, TN (India)

2016-10-15

The present study highlights the uranium (U) concentrations in water–soil–plant matrices and the efficiency considering a heterogeneous assemblage of terrestrial and aquatic native plant species to act as the biomonitor and phytoremediator for environmental U-contamination in the Sevilha mine (uraniferous region of Beiras, Central Portugal). A total of 53 plant species belonging to 22 families was collected from 24 study sites along with ambient soil and/or water samples. The concentration of U showed wide range of variations in the ambient medium: 7.5 to 557 mg kg{sup −} {sup 1} for soil and 0.4 to 113 μg L{sup −} {sup 1} for water. The maximum potential of U accumulation was recorded in roots of the following terrestrial plants: Juncus squarrosus (450 mg kg{sup −} {sup 1} DW), Carlina corymbosa (181 mg kg{sup −} {sup 1} DW) and Juncus bufonius (39.9 mg kg{sup −} {sup 1} DW), followed by the aquatic macrophytes, namely Callitriche stagnalis (55.6 mg kg{sup −} {sup 1} DW) Lemna minor (53.0 mg kg{sup −} {sup 1} DW) and Riccia fluitans (50.6 mg kg{sup −} {sup 1} DW). Accumulation of U in plant tissues exhibited the following decreasing trend: root > leaves > stem > flowers/fruits and this confirms the unique efficiency of roots in accumulating this radionuclide from host soil/sediment (phytostabilization). Overall, the accumulation pattern in the studied aquatic plants (L. minor, R. fluitans, C. stagnalis and Lythrum portula) dominated over most of the terrestrial counterpart. Among terrestrial plants, the higher mean bioconcentration factor (≈ 1 in roots/rhizomes of C. corymbosa and J. squarrosus) and translocation factor (31 in Andryala integrifolia) were encountered in the representing families Asteraceae and Juncaceae. Hence, these terrestrial plants can be treated as the promising candidates for the development of the phytostabilization or phytoextraction methodologies based on the accumulation, abundance and biomass production

Translocation of iodine-129 in soil and transfer to vegetation

International Nuclear Information System (INIS)

Handl, J.

1989-01-01

The translocation of I-129 in the soil and its long-term transfer from soil to plant have been investigated using an undisturbed soil column and a pasture on a river bank. The I-129 profiles in the soils of the monolith and the pasture exhibit clear differences in the distribution of radioiodine after 52 and 47 months, respectively. At those times after surface contamination of both soil types 88% (monolith) and 66% (pasture) of the total I-129 activity were found in the top soil layer of 10 cm, indicating that translocation in the pasture soil is faster than in the monolith. Apart from soil-specific parameters this behaviour may be explained by anaerobic conditions created in the soil due to high water levels in the nearby river attecting the chemical form of iodine. The distribution of stable iodine was found rather homogeneous in both soils with mean contents of 3 mg I-127 kg -1 d.w. in the upper 15 cm and 4 mg I-127 kg -1 d.w. in deeper layers in case of the monolith. For the pasture soil the corresponding values are about 4 and 5 mg I-127 kg -1 d.w. Transfer factors plant/soil (dry weight basis) of I-129 obtained from the monolith 39 g and 52 months after contamination are 1.5x10 -3 and 2.1x10 -3 , respectively. Data from the pasture 35 and 47 months after contamination show values of 9.0x10 -3 and 8.4x10 -3 , respectively. Transfer factors of stable iodine are significantly higher in both soils yielding an average value of 1.0 for the monolith and 0.3 for the pasture. Delay constants (related to a top soil layer of 10 cm) calculated for I-129 using data obtained from the long-term translocation processes to deeper soil layers in the monolith and in the pasture show values of 1x10 -9 s -1 and 4x10 -9 s -1 , respectively. (orig.) [de

Electrostaticspray preparation and properties of RDX/DOS composites

Directory of Open Access Journals (Sweden)

Jian Yao

2017-08-01

Full Text Available A composite explosive based on 1, 3, 5-trinitro-1, 3, 5-triazinane (RDX was prepared by electrostaticspray method with dioctyl sebacate (DOS as desensitizer. After preparation, the particle size and crystal structure were characterized and chemical features, such as chemical bonds, functional groups, thermal decomposition parameters and mechanical sensitivity were investigated as well. In terms of the morphologies of the composites, the particle sizes were in the range of 1–3 μm. Compared with RDX, the crystal types, chemical bonds and functional groups of the RDX/DOS composites were unchanged. The activation energy of the composites was lower than that of raw RDX, and the 3wt % DOS composites had the lowest activation energy. The impact sensitivity and friction sensitivity of the RDX/DOS composites were lower than those of raw RDX, and the 10wt% DOS composites had the highest H50 (125.9 cm and the lowest friction sensitivity (8%.

Transfer of 226Ra to plants from two types of soil

International Nuclear Information System (INIS)

Rosiak, L.; Pietrzak-Flis, Z.

1998-01-01

The transfer of 226 Ra to plants used as food (carrot, parsley, wheat) and as fodder (grass, maize) was studied. The plants were grown on two types of soil: sandy soil (l) and sandy loam soil (II) in an open field (exposure to dry and wet deposition, resuspension and soil adhesion) and in polyethylene tent with an underground irrigation system (isolation from wet deposition and from water splash on soil). The plants were grown simultaneously on the open and sheltered fields. The average concentrations of total 226 Ra and of exchangeable 226 Ra were 8.48 ± 0.50 Bq/kg dw was 0.62 ± 0.07 Bq/kg dw , respectively, in Soil I and 12.2 ± 0.56 Bq/kg dw and 0.66 ± 0.05 Bq/kg dw , respectively, in Soil II. 226 Ra was determined in the above-ground parts of the plants after washing in distilled water, in the rinse obtained from washing, in the insoluble residue separated from the rinse, and in the roots. The data obtained allowed us to determine the incorporated radionuclide in the plants and on their surface. Statistical analysis of the data indicates that there is no difference in the incorporated 226 Ra for plants grown on the open field and in the tent. This indicates that Ra enter the plants mainly through the root system, while the pathway via leaves and stems is negligible

The uptake of Cs and Sr from soil to radish (Raphanus sativus L.)- potential for phytoextraction and remediation of contaminated soils

International Nuclear Information System (INIS)

Wang, Dan; Wen, Fangping; Xu, Changhe; Tang, Yunlai; Luo, Xuegang

2012-01-01

The 133 Cs and 88 Sr uptake by plant Raphanus sativus L. was studied during cultivation in outdoor potted-soil. The distribution, accumulation of 133 Cs, 88 Sr and the antioxidant responses in plants were measured after 30 and 60 days of cultivation. The results showed that the uptake capacity of radish for 88 Sr was far higher than that for 133 Cs when the concentration of 88 Sr was as the same as that of 133 Cs in the soil (The concentration of 88 Sr or 133 Cs in the soil was from 2.5 mg kg −1 to 40 mg kg −1 ). The highest 88 Sr accumulation was 239.18 μg g −1 dw, otherwise, the highest 133 Cs accumulation was 151.74 μg g −1 dw (The concentration of 88 Sr in the soil was 40 mg kg −1 ), and the lowest 88 Sr accumulation was 131.03 μg g −1 dw, otherwise, the lowest 133 Cs accumulation was 12.85 μg g −1 dw (The concentration of 88 Sr in the soil is 5 mg kg −1 ). The 88 Sr and 133 Cs TF values were 1.16–1.72 and 0.24–0.60, respectively. There was little influence of high concentration of 88 Sr on the total biomass of plants, so the radish is one of the ideal phytoremediation plant for Sr polluted soils. The important physiological reasons that radish had good tolerance to 88 Sr stress were that the MDA content was higher under the 88 Sr stress than that under the 133 Cs stress, and the activities of POD and CAT were lower under the 88 Sr stress than that under 133 Cs stress. - Highlights: ► Radish is a kind of native plant with high biomass and fast growth. Its uptake capacity of radish for 88 Sr was far higher than that for 133 Cs when the concentration of 88 Sr was the same as that of 133 Cs in the soil. ► The TF values of radish for 88 Sr were 1.16–1.72. ► Radish is one of the ideal phytoremediation plant for Sr polluted soils. ► The important physiological reasons that radish had good tolerance toward 88 Sr stress were that the MDA content was higher under the 88 Sr stress than under the 133 Cs stress, and the activities of POD

Bioconcentration of TNT and RDX in coastal marine biota.

Science.gov (United States)

Ballentine, Mark; Tobias, Craig; Vlahos, Penny; Smith, Richard; Cooper, Christopher

2015-05-01

The bioconcentration factor (BCF) was measured for 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in seven different marine species of varying trophic levels. Time series and concentration gradient treatments were used for water column and tissue concentrations of TNT, RDX, and their environmentally important derivatives 2-amino-4,6-dintrotoluene (2-ADNT) and 4-amino-2,6-dinitrotoluene (4-ADNT). BCF values ranged from 0.0031 to 484.5 mL g(-1) for TNT and 0.023 to 54.83 mL g(-1) for RDX. The use of log K ow value as an indicator was evaluated by adding marine data from this study to previously published data. For the munitions in this study, log K ow value was a good indicator in the marine environment. The initial uptake and elimination rates of TNT and RDX for Fucus vesiculosus were 1.79 and 0.24 h(-1) for TNT and 0.50 and 0.0035 h(-1) for RDX respectively. Biotransformation was observed in all biota for both TNT and RDX. Biotransformation of TNT favored 4-ADNT over 2-ADNT at ratios of 2:1 for F. vesiculosus and 3:1 for Mytilus edulis. Although RDX derivatives were measureable, the ratios of RDX derivatives were variable with no detectable trend. Previous approaches for measuring BCF in freshwater systems compare favorably with these experiments with marine biota, yet significant gaps on the ultimate fate of munitions within the biota exist that may be overcome with the use stable isotope-labeled munitions substrates.

Effect of different spiking procedures on the distribution and toxicity of ZnO nanoparticles in soil.

Science.gov (United States)

Waalewijn-Kool, Pauline L; Diez Ortiz, Maria; van Gestel, Cornelis A M

2012-10-01

Due to the difficulty in dispersing some engineered nanomaterials in exposure media, realizing homogeneous distributions of nanoparticles (NP) in soil may pose major challenges. The present study investigated the distribution of zinc oxide (ZnO) NP (30 nm) and non-nano ZnO (200 nm) in natural soil using two different spiking procedures, i.e. as dry powder and as suspension in soil extract. Both spiking procedures showed a good recovery (>85 %) of zinc and based on total zinc concentrations no difference was found between the two spiking methods. Both spiking procedures resulted in a fairly homogeneous distribution of the ZnO particles in soil, as evidenced by the low variation in total zinc concentration between replicate samples (soil spiked at concentrations up to 6,400 mg Zn kg(-1) d.w. was not affected for both compounds. Reproduction was reduced in a concentration-dependent manner with EC50 values of 3,159 and 2,914 mg Zn kg(-1) d.w. for 30 and 200 nm ZnO spiked as dry powder and 3,593 and 5,633 mg Zn kg(-1) d.w. introduced as suspension. Toxicity of ZnO at 30 and 200 nm did not differ. We conclude that the ZnO particle toxicity is not size related and that the spiking of the soil with ZnO as dry powder or as a suspension in soil extract does not affect its toxicity to F. candida.

Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt

Science.gov (United States)

Kříbek, B.; Majer, V.; Knésl, I.; Nyambe, I.; Mihaljevič, M.; Ettler, V.; Sracek, O.

2014-11-01

The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves and washed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminated and contaminated soils of the Zambian Copperbelt mining district have been analyzed. An enrichment index (EI) was used to distinguish between contaminated and uncontaminated areas. This index is based on the average ratio of the actual and median concentration of the given contaminants (As, Co, Cu, mercury (Hg), Pb and Zn) in topsoil. The concentrations of copper in cassava leaves growing on contaminated soils reach as much as 612 mg kg-1 Cu (total dry weight [dw]). Concentrations of copper in leaves of cassava growing on uncontaminated soils are much lower (up to 252 mg kg-1 Cu dw). The concentrations of Co (up to 78 mg kg-1 dw), As (up to 8 mg kg-1 dw) and Zn (up to 231 mg kg-1 dw) in leaves of cassava growing on contaminated soils are higher compared with uncontaminated areas, while the concentrations of lead do not differ significantly. The concentrations of analyzed chemical elements in the tubers of cassava are much lower than in its leaves with the exception of As. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassava do not exceed the daily maximum tolerance limit of 0.5 mg kg-1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The highest tolerable weekly ingestion of 0.025 mg kg-1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg-1/HBW for arsenic are exceeded predominantly in the vicinity of smelters. Therefore, the preliminary assessment of dietary exposure to metals through the consumption of uncooked cassava leaves and tubers has been identified as a moderate hazard to human health. Nevertheless, as the surfaces of leaves are strongly contaminated by metalliferous dust in the polluted areas, there is still a potential hazard

Accumulation, allocation, and risk assessment of polycyclic aromatic hydrocarbons (PAHs in soil-Brassica chinensis system.

Directory of Open Access Journals (Sweden)

Juan Zhang

Full Text Available Farmland soil and leafy vegetables accumulate more polycyclic aromatic hydrocarbons (PAHs in suburban sites. In this study, 13 sampling areas were selected from vegetable fields in the outskirts of Xi'an, the largest city in northwestern China. The similarity of PAH composition in soil and vegetation was investigated through principal components analysis and redundancy analysis (RDA, rather than discrimination of PAH congeners from various sources. The toxic equivalent quantity of PAHs in soil ranged from 7 to 202 μg/kg d.w., with an average of 41 μg/kg d.w., which exceeded the agricultural/horticultural soil acceptance criteria for New Zealand. However, the cancer risk level posed by combined direct ingestion, dermal contact, inhalation of soil particles, and inhalation of surface soil vapor met the rigorous international criteria (1 × 10(-6. The concentration of total PAHs was (1052 ± 73 μg/kg d.w. in vegetation (mean ± standard error. The cancer risks posed by ingestion of vegetation ranged from 2×10-5 to 2 × 10(-4 with an average of 1.66 × 10(-4, which was higher than international excess lifetime risk limits for carcinogens (1 × 10(-4. The geochemical indices indicated that the PAHs in soil and vegetables were mainly from vehicle and crude oil combustion. Both the total PAHs in vegetation and bioconcentration factor for total PAHs (the ratio of total PAHs in vegetation to total PAHs in soil increased with increasing pH as well as decreasing sand in soil. The total variation in distribution of PAHs in vegetation explained by those in soil reached 98% in RDA, which was statistically significant based on Monte Carlo permutation. Common pollution source and notable effects of soil contamination on vegetation would result in highly similar distribution of PAHs in soil and vegetation.

Evaluation of the metabolic fate of munitions material (TNT & RDX) in plant systems and initial assessment of material interaction with plant genetic material. Validation of the metabolic fate of munitions materials (TNT, RDX) in mature crops

Energy Technology Data Exchange (ETDEWEB)

Fellows, R.J.; Harvey, S.D.; Cataldo, D.A.

1995-09-01

The goals of this effort were to confirm and expand data related to the behavior and impacts of munitions residues upon human food chain components. Plant species employed included corn (Zea mays), alfalfa (Medicago sativa). spinach (Spinacea oleraceae), and carrot (Daucus carota). Plants were grown from seed to maturity (70 to 120 days) in a low-fertility soil (Burbank) amended with either {sup 14}C-TNT or {sup 14}C-RDX at which time they were harvested and analyzed for munitions uptake, partitioning, and chemical form of the munition or munition-metabolite. All four of the plant species used in this study accumulated the {sup 14}C-TNT- and RDX-derived label. The carrot, alfalfa, and corn demonstrated a higher percentage of label retained in the roots (62, 73, and 83% respectively). The spinach contained less activity in its root (36%) but also contained the highest TNT specific activity observed (>4600 jig TNT equivalents/g dry wt.). The specific uptake values of RDX for the spinach and alfalfa were comparable to those previously reported for wheat and bean (314 to 590 {mu}g RDX-equivalents/g dry wt. respectively). An exception to this may be the carrot where the specific activity was found to exceed 4200 {mu}g RDX-equivalents/g dry wt. in the shoot. The total accumulation of TNT by the plants ranged from 1.24% for the spinach to 2.34% for the carrot. The RDX plants ranging from 15% for the spinach to 37% for the carrot. There was no identifiable TNT or amino dinitrotoluene (ADNT) isomers present in the plants however, the parent RDX compound was found at significant levels in the shoot of alfalfa (> 1 80 {mu}g/g) and corn (>18 {mu}g/g).

MIRABEL DW

DEFF Research Database (Denmark)

Siksnys, Laurynas; Thomsen, Christian; Pedersen, Torben Bach

2015-01-01

of flex-offers which define flexibility with respect to time, amount, and/or price. In this paper, we describe MIRABEL DW, a data warehouse (DW) for the management of the large amounts of complex energy data in MIRABEL. We present a unified schema that can manage data both at the level of the entire...

Plant uptake of radiocesium from contaminated soils

International Nuclear Information System (INIS)

Pipiska, M.; Lesny, J.; Hornik, M.; Augustin, J.

2004-01-01

Phytoextraction field experiments were conducted on soil contaminated with radiocesium to determine the capacity of autochthonous grasses and weeds to accumulate 137 Cs. The aim of the study was to evaluate the potential of spontaneously growing vegetation as a tool for decontamination of non-agricultural contaminated land. As a test field, the closed monitored area of the radioactive wastewater treatment plant of the Nuclear Power Plant in Jaslovskie Bohunice, Slovakia was used. contamination was irregularly distributed from the level of background to spots with maximal activity up to 900 Bq/g soil. Sequential extraction analysis of soil samples showed the following extractability of radiocesium (as percent of total): water 2 = 0.3-1.1%; 1M CH 3 COONa = 0.3-0.9%; 0.04 M NH 4 Cl (in 25% CH 3 COOH) = 0.9-1.4% and 30% H 2 O 2 - 0.02 M HNO 3 = 4.5-9.0%.Specific radioactivity of the most efficiently bioaccumulating plant species did not exceed 4.0 BqKg -1 (dry weight biomass). These correspond to the soil-to-plant transfer factor (TF) values up to 44.4x10 -4 BqKg -1 crop, d.w.)/(BqKg -1 soil d.w). Aggregated transfer factor (T ag ) of the average sample of the whole crop harvested from defined area was 0.5x10 -5 (Bqkg -1 d.w. crop)/(Bqm -2 soil). It can be concluded that low mobility of radiocesium in analysed soil type, confirmed by sequential extraction analyses, is the main hindrance for practical application for autochthonous plants as a phytoremediation tool for aged contaminated area of non-cultivated sites. Plant cover can efficiently serve only as a soil surface-stabilising layer, mitigating the migration of radiocesium into the surrounding environment. (author)

Bioremediation of RDX in the vadose zone beneath the Pantex Plant

Energy Technology Data Exchange (ETDEWEB)

Shull, T.L.; Speitel, G.E. Jr.; McKinney, D.C. [Univ. of Texas, Austin, TX (United States). Dept. of Civil Engineering

1999-01-01

The presence of dissolved high explosives (HE), in particular RDX and HMX, is well documented in the perched aquifer beneath the Pantex Plant, but the distribution of HE in the vadose zone has not yet been well defined. Although current remediation activities focus on the contamination in the perched aquifer, eventually regulatory concern is likely to turn to the residual contamination in the vadose zone. Sources of HE include the infiltration of past wastewater discharges from several HE-processing facilities through the ditch drainage system and leachate from former Landfill 3. With limited existing data on the HE distribution in the vadose zone and without preventive action, it must be assumed that residual HE could be leached into infiltrating water, providing a continuing supply of contamination to the perched aquifer. The purpose of this project was to more closely examine the fate and transport of HE in the vadose zone through mathematical modeling and laboratory experimentation. In particular, this report focuses on biodegradation as one possible fate of HE. Biodegradation of RDX in the vadose zone was studied because it is both present in highest concentration and is likely to be of the greatest regulatory concern. This study had several objectives: determine if indigenous soil organisms are capable of RDX biodegradation; determine the impact of electron acceptor availability and nutrient addition on RDX biodegradation; determine the extent of RDX mineralization (i.e., conversion to inorganic carbon) during biodegradation; and estimate the kinetics of RDX biodegradation to provide information for mathematical modeling of fate and transport.

Application of 13C-stable isotope probing to identify RDX-degrading microorganisms in groundwater

International Nuclear Information System (INIS)

Cho, Kun-Ching; Lee, Do Gyun; Roh, HyungKeun; Fuller, Mark E.; Hatzinger, Paul B.; Chu, Kung-Hui

2013-01-01

We employed stable isotope probing (SIP) with 13 C-labeled hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) to identify active microorganisms responsible for RDX biodegradation in groundwater microcosms. Sixteen different 16S rRNA gene sequences were derived from microcosms receiving 13 C-labeled RDX, suggesting the presence of microorganisms able to incorporate carbon from RDX or its breakdown products. The clones, residing in Bacteroidia, Clostridia, α-, β- and δ-Proteobacteria, and Spirochaetes, were different from previously described RDX degraders. A parallel set of microcosms was amended with cheese whey and RDX to evaluate the influence of this co-substrate on the RDX-degrading microbial community. Cheese whey stimulated RDX biotransformation, altered the types of RDX-degrading bacteria, and decreased microbial community diversity. Results of this study suggest that RDX-degrading microorganisms in groundwater are more phylogenetically diverse than what has been inferred from studies with RDX-degrading isolates. Highlights: •SIP identified sixteen groundwater bacteria capable of using RDX and/or its metabolites as a carbon source. •The RDX degraders in groundwater are phylogenetically diverse and different from known RDX degraders. •Cheese whey induced community shift and altered diversity of the RDX-degrading microorganisms over time. -- RDX-degrading bacteria in contaminated groundwater, identified by SIP with 13 C-labeled RDX, are phylogenetically diverse and different from known RDX degraders

Synthesis of 14C-Labelled Octahydor-1,3,5,7-Tetranitro-1,3,5,7-Tetrazocine (HMx0 and 15N-Isotopic Hexahyrro-1,3,5-Trinitro-1,3,5-Triazine (RDX) for use in Microcosm Experiments

National Research Council Canada - National Science Library

Ampleman, G

2000-01-01

Within the framework of an R & D project on bioremediation of soils contaminated with energetic compounds, the biodegradation of energetic nitramine products such as octogen (HMX) and hexogen (RDX) is under study...

Biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by a prospective consortium and its most effective isolate Serratia marcescens

Energy Technology Data Exchange (ETDEWEB)

Young, D.M.; Ogden, K.L. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Chemical and Environmental Engineering; Unkefer, P.J. [Los Alamos National Lab., NM (United States). Chemical Science and Technology Div.

1997-03-05

The biotransformation of hexahydro-1,3,5-trinitro-1,3,5 triazine (RDX) has been observed in liquid culture by a consortium of bacteria found in horse manure. Five types of bacteria were found to predominate in the consortium and were isolated. The most effective of these isolates at transforming RDX was Serratia marcescens. The biotransformation of RDX by all of these bacteria was found to occur only in the anoxic stationary phase. The process of bacterial growth and RDX biotransformation was quantified for the purpose of developing a predictive type model. Cell growth was assumed to follow Monod kinetics. All of the aerobic and anoxid growth parameters were determined: {mu}{sub max}, K{sub s}, and Y{sub x/s}. RDX was found to competitively inhibit cell growth in both atmospheres. Degradation of RDX by Serratia marcescens was found to proceed through the stepwise reduction of the three nitro groups to nitroso groups. Each of these reductions was found to be first order in both component and cell concentrations. The degradation rate constant for the first step in this reduction process by the consortium was 0.022 L/g cells {center_dot} h compared to 0.033 L/g cells {center_dot} h for the most efficient isolate.

Plant community tolerant to trace elements growing on the degraded soils of São Domingos mine in the south east of Portugal: environmental implications.

Science.gov (United States)

Freitas, H; Prasad, M N V; Pratas, J

2004-03-01

The selection of trace element tolerant species is a key factor to the success of remediation of degraded mine soils. Mining activities generate a large amount of waste rocks and tailings, which get deposited at the surface. The degraded soils, the waste rocks and tailings are often very unstable and will become sources of pollution. The direct effects will be the loss of cultivated land, forest or grazing land, and the overall loss of production. The indirect effects will include air and water pollution and siltation of rivers. These will eventually lead to the loss of biodiversity, amenity and economic wealth. Restoration of a vegetation cover can fulfil the objectives of stabilization, pollution control, visual improvement and removal of threats to human beings. Thus, remediation of mine spoils/tailings and biogeochemical prospecting would rely on the appropriate selection of plant species. Plant community responds differently on their ability to uptake or exclude a variety of metals. In this work, plant species were sampled from all populations established in an abandoned copper mine of São Domingos, SE Portugal. Plants belonging to 24 species, 16 genera and 13 families were collected from the degraded copper mine of São Domingos. Plant samples were analysed for total Ag, As, Cu, Ni, Pb, and Zn. The highest concentrations of metals in soils dry matter were 11217.5 mg Pb kg(-1), 1829 mg Cu kg(-1), 1291 mg As kg(-1), 713.7 mg Zn kg(-1), 84.6 mg Cr kg(-1), 54.3 mg Co kg(-1), 52.9 mg Ni kg(-1) and 16.6 mg Ag kg(-1). With respect to plants, the higher concentrations of Pb and As were recorded in the semi-aquatic species Juncus conglomeratus with 84.8 and 23.5 mg kg(-1) dry weight (DW), Juncus efusus with 22.4 and 8.5 mg kg(-1) DW, and Scirpus holoschoenus with 51.7 and 8.0 mg kg(-1) DW, respectively. Thymus mastichina also showed high content of As in the aboveground parts, 13.6 mg kg(-1) DW. Overall, the results indicate accumulation of various metals by

Concentrations, distribution, sources and risk assessment of organohalogenated contaminants in soils from Kenya, Eastern Africa

International Nuclear Information System (INIS)

Sun, Hongwei; Qi, Yueling; Zhang, Di; Li, Qing X.; Wang, Jun

2016-01-01

The organohalogenated contaminants (OCs) including 12 organochlorine pesticides (OCPs), 7 indicator polychlorinated biphenyls (PCBs) and 7 polybrominated diphenyl ethers (PBDEs) were determined in soils collected from Kenya, Eastern Africa. The total OCPs fell in the range of n.d–49.74 μg kg"−"1 dry weight (dw), which was dominated by DDTs and endosulfan. Identification of pollution sources indicated new input of DDTs for malaria control in Kenya. The total PCBs ranged from n.d. to 55.49 μg kg"−"1 dw, dominated by penta- and hexa-PCBs, probably associated with the leakage of obsolete transformer oil. The soils were less contaminated by PBDEs, ranging from 0.19 to 35.64 μg kg"−"1 dw. The predominant PBDE congeners were penta-, tri- or tetra-BDEs, varying among different sampling sites. Risk assessment indicated potential human health risks posed by OCs in soils from Kenya, with PCBs as the most contributing pollutants. The local authorities are recommended to make best efforts on management of OC pollution, particularly from DDTs and PCBs to meet the requirement of Stockholm Convention. - Highlights: • The first report on organohalogen contaminants (OCs) in soils from Kenya. • OCs including OCPs, PCBs and PBDEs were determined simultaneously. • Sources of OCPs, PCBs and PBDEs emission were identified. • Human health risk posed by OCs in soil from Kenya were assessed. • Measures for OCs management were suggested for local authority. - The soils from Kenya were heavily polluted by organohalogenated contaminants (OCs). New input of DDTs probably occurred. Among all OCs, PCBs were predominant.

Phytoremediation of cadmium contaminated soils by tuberose

International Nuclear Information System (INIS)

Ramana, S.; Biswas, A.K.; Singh, A.B.; Ajay; Ahirwar, N.K.; Behera, S.K.; Subba Rao, A.; Naveen Kumar, P.

2012-01-01

The potential of three varieties of tuberose (Prajwal, Shringar and Mexican single) for phytoremediation of soil contaminated with cadmium was evaluated by subjecting the plants to five levels of Cd (0, 25, 50, 75 and 100 mg kg -1 soil). Applied Cd did not produce any toxic symptoms in all the three varieties of tuberose except marginal reduction in the photosynthesis rate and total dry weight beyond 50 mg Cd kg -1 soil. The study showed that tuberose possessed the typical ability of Cd hyper accumulator characterized by (1) accumulation of Cd in the shoots of the plant exceeding the critical judging standard i.e., 100 μg g -1 DW and (2) ratio of Cd in the shoots to bulbs >1. It was concluded that tuberose may be an effective accumulator plant for phytoremediation of cadmium polluted soils. (author)

Identification of groundwater microorganisms capable of assimilating RDX-derived nitrogen during in-situ bioremediation

International Nuclear Information System (INIS)

Cho, Kun-Ching; Fuller, Mark E.; Hatzinger, Paul B.; Chu, Kung-Hui

2016-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a nitroamine explosive, is commonly detected in groundwater at military testing and training sites. The objective of this study was to characterize the microbial community capable of using nitrogen derived from the RDX or RDX intermediates during in situ bioremediation. Active groundwater microorganisms capable of utilizing nitro-, ring- or fully-labeled "1"5N-RDX as a nitrogen source were identified using stable isotope probing (SIP) in groundwater microcosms prepared from two wells in an aquifer previously amended with cheese whey to promote RDX biodegradation. A total of fifteen 16S rRNA gene sequences, clustered in Clostridia, β-Proteobacteria, and Spirochaetes, were derived from the "1"5N-labeled DNA fractions, suggesting the presence of metabolically active bacteria capable of using RDX and/or RDX intermediates as a nitrogen source. None of the derived sequences matched RDX-degrading cultures commonly studied in the laboratory, but some of these genera have previously been linked to RDX degradation in site groundwater via "1"3C-SIP. When additional cheese whey was added to the groundwater samples, 28 sequences grouped into Bacteroidia, Bacilli, and α-, β-, and γ-Proteobacteria were identified. The data suggest that numerous bacteria are capable of incorporating N from ring- and nitro-groups in RDX during anaerobic bioremediation, and that some genera may be involved in both C and N incorporation from RDX. - Highlights: • Cheese whey addition resulted in 28 different clones associated with RDX degradation. • The 28 clones belong to Bacteroidia, Bacilli, and α-, β-, and γ-Proteobacteria. • SIP identified 15 clones using RDX and/or its metabolites as a nitrogen source. • The clones clustered in Clostridia, β-Proteobacteria, and Spirochaetes

Effect of Nano-Magnesium Hydride on the Thermal Decomposition Behaviors of RDX

International Nuclear Information System (INIS)

Yao, M.; Chen, L.; Rao, G.; Peng, J.; Zou, J.; Zeng, X.

2013-01-01

In order to improve the detonation performance of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) explosive, addictive with high heat values were used, and magnesium hydride (MgH 2 ) is one of the candidates. However, it is important to see whether MgH 2 is a safe addictive. In this paper, the thermal and kinetic properties of RDX and mixture of RDX/MgH 2 were investigated by differential scanning calorimeter (DSC) and accelerating rate calorimeter (ARC), respectively. The apparent activation energy (E) and frequency factor (A) of thermal explosion were calculated based on the data of DSC experiments using the Kissinger and Ozawa approaches. The results show that the addition of MgH 2 decreases both E and A of RDX, which means that the mixture of RDX/MgH 2 has a lower thermal stability than RDX, and the calculation results obtained from the ARC experiments data support this too. Besides, the most probable mechanism functions about the decomposition of RDX and RDX/MgH 2 were given in this paper which confirmed the change of the decomposition mechanism.

Mechanism of RDX-Induced Seizures in Rats

Science.gov (United States)

2009-09-01

benchmark for RDX. d. The main acute effect of RDX after ingestion of high doses is the induction of seizures accompanied by excessive salivation ...most animals that seize demonstrate excessive salivation (Schneider et al., 1977; Burdette et al., 1988; Crouse et al., 2006). These clinical signs...Padilla et al., 1998). A 2% (wet wt./vol.) homogenate was made in 0.1 M Na phosphate buffer ( pH 8.0) + 1% Triton, using a 20 sec burst (on ice) of

Relationship between RDX properties and sensitivity

Energy Technology Data Exchange (ETDEWEB)

Doherty, Ruth M. [Research, Development, Test and Evaluation Directorate, Naval Surface Warfare Center Indian Head Division, Indian Head, MD 20640-5102 (United States); Watt, Duncan S. [Novare, Level 6 80 Petrie Terrace, Brisbane 4000 (Australia)

2008-02-15

An interlaboratory comparison of seven lots of commercially available RDX was conducted to determine what properties of the nitramine particles can be used to assess whether the RDX has relatively high or relatively low sensitivity. The materials chosen for the study were selected to give a range of HMX content, manufacturing process and reported shock sensitivity. The results of two different shock sensitivity tests conducted on a PBX made with the RDX lots in the study showed that there are measurable differences in the shock sensitivity of the PBXs, but the impact sensitivity for all of the lots is essentially the same. Impact sensitivity is not a good predictor of shock sensitivity for these types of RDX. Although most RDX that exhibits RS has low HMX content, that characteristic alone is not sufficient to guarantee low sensitivity. A range of additional analytical chemistry tests were conducted on the material; two of these (HPLC and DSC) are discussed within. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Impact assessment of intermediate soil cover on landfill stabilization by characterizing landfilled municipal solid waste.

Science.gov (United States)

Qi, Guangxia; Yue, Dongbei; Liu, Jianguo; Li, Rui; Shi, Xiaochong; He, Liang; Guo, Jingting; Miao, Haomei; Nie, Yongfeng

2013-10-15

Waste samples at different depths of a covered municipal solid waste (MSW) landfill in Beijing, China, were excavated and characterized to investigate the impact of intermediate soil cover on waste stabilization. A comparatively high amount of unstable organic matter with 83.3 g kg(-1) dry weight (dw) total organic carbon was detected in the 6-year-old MSW, where toxic inorganic elements containing As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn of 10.1, 0.98, 85.49, 259.7, 530.4, 30.5, 84.0, and 981.7 mg kg(-1) dw, respectively, largely accumulated because of the barrier effect of intermediate soil cover. This accumulation resulted in decreased microbial activities. The intermediate soil cover also caused significant reduction in moisture in MSW under the soil layer, which was as low as 25.9%, and led to inefficient biodegradation of 8- and 10-year-old MSW. Therefore, intermediate soil cover with low permeability seems to act as a barrier that divides a landfill into two landfill cells with different degradation processes by restraining water flow and hazardous matter. Copyright © 2013 Elsevier Ltd. All rights reserved.

RDX binds to the convulsant site of the GABAA receptor and increases spontaneous firing rates of cortical neurons in vitro

Science.gov (United States)

RDX (hexahydro-1 ,3,5-trinitro-1 ,3,5-triazine, hexogen, Royal Demolition eXplosive) is an explosive widely used by the military and has been found in soil and ground water in and surrounding training ranges, creating potential hazards to the environment and human health. Oral RD...

Evaluation of the halophyte Salsola soda as an alternative crop for saline soils high in selenium and boron.

Science.gov (United States)

Centofanti, Tiziana; Bañuelos, Gary

2015-07-01

Urbanization, industrial development, and intensive agriculture have caused soil contamination and land degradation in many areas of the world. Salinization is one important factor contributing to land degradation and it affects agricultural production and environmental quality. When salinization is combined with soil pollution by trace elements, as it occurs in many arid and semi-arid regions around the world, strategies to phyto-manage pollutants and sustain crop production need to be implemented. In this study, we present the case of saline soils in the West side of Central California which contain naturally-occurring selenium (Se), boron (B), and other salts, such as NaCl, CaCl2, Na2SO4, and Na2SeO4. To sustain crop production on Se- and B-laden arid saline soils, we investigated the potential of the halophyte "agretti" (Salsola soda L.) as an alternative crop. The aim of our greenhouse study was to examine adaptability, B tolerance, and Se accumulation by S. soda grown on soils collected from a typical saline-laden field site located on the West side of the San Joaquin Valley (SJV). Our results showed that S. soda tolerates the saline (EC ∼ 10 dS m(-1)) and B-laden soils (10 mg B L(-1)) of the SJV even with the additional irrigation of saline and B rich water (EC ∼ 3 dS m(-1) and 4 mg B L(-1)). Under these growing conditions, the plant can accumulate high concentrations of Na (80 g Na kg(-1) DW), B (100 mg B kg(-1) DW), and Se (3-4 mg Se kg(-1) DW) without showing toxicity symptoms. Hence, S. soda showed promising potential as a plant species that can be grown in B-laden saline soils and accumulate and potentially manage excessive soluble Se and B in soil. Copyright © 2015 Elsevier Ltd. All rights reserved.

IRIS Toxicological Review of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (RDX) (Public Comment Draft)

Science.gov (United States)

EPA is developing an Integrated Risk Information System (IRIS) assessment of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and has released the draft assessment for public comment. When final, the assessment will appear on the IRIS database.

In situ pilot test for bioremediation of energetic compound-contaminated soil at a former military demolition range site.

Science.gov (United States)

Jugnia, Louis B; Manno, Dominic; Drouin, Karine; Hendry, Meghan

2018-05-04

Bioremediation was performed in situ at a former military range site to assess the performance of native bacteria in degrading hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and 2,4-dinitrotoluene (2,4-DNT). The fate of these pollutants in soil and soil pore water was investigated as influenced by waste glycerol amendment to the soil. Following waste glycerol application, there was an accumulation of organic carbon that promoted microbial activity, converting organic carbon into acetate and propionate, which are intermediate compounds in anaerobic processes. This augmentation of anaerobic activity strongly correlated to a noticeable reduction in RDX concentrations in the amended soil. Changes in concentrations of RDX in pore water were similar to those observed in the soil suggesting that RDX leaching from the soil matrix, and treatment with waste glycerol, contributed to the enhanced removal of RDX from the water and soil. This was not the case with 2,4-DNT, which was neither found in pore water nor affected by the waste glycerol treatment. Results from saturated conditions and Synthetic Precipitation Leaching Procedure testing, to investigate the environmental fate of 2,4-DNT, indicated that 2,4-DNT found on site was relatively inert and was likely to remain in its current state on the site.

Identification of groundwater microorganisms capable of assimilating RDX-derived nitrogen during in-situ bioremediation

Energy Technology Data Exchange (ETDEWEB)

Cho, Kun-Ching [Zachry Department of Civil Engineering, Texas A& M University, College Station, TX 77843-3136 (United States); Fuller, Mark E.; Hatzinger, Paul B. [CB& I Federal Services, Lawrenceville, NJ 08648 (United States); Chu, Kung-Hui, E-mail: kchu@civil.tamu.edu [Zachry Department of Civil Engineering, Texas A& M University, College Station, TX 77843-3136 (United States)

2016-11-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), a nitroamine explosive, is commonly detected in groundwater at military testing and training sites. The objective of this study was to characterize the microbial community capable of using nitrogen derived from the RDX or RDX intermediates during in situ bioremediation. Active groundwater microorganisms capable of utilizing nitro-, ring- or fully-labeled {sup 15}N-RDX as a nitrogen source were identified using stable isotope probing (SIP) in groundwater microcosms prepared from two wells in an aquifer previously amended with cheese whey to promote RDX biodegradation. A total of fifteen 16S rRNA gene sequences, clustered in Clostridia, β-Proteobacteria, and Spirochaetes, were derived from the {sup 15}N-labeled DNA fractions, suggesting the presence of metabolically active bacteria capable of using RDX and/or RDX intermediates as a nitrogen source. None of the derived sequences matched RDX-degrading cultures commonly studied in the laboratory, but some of these genera have previously been linked to RDX degradation in site groundwater via {sup 13}C-SIP. When additional cheese whey was added to the groundwater samples, 28 sequences grouped into Bacteroidia, Bacilli, and α-, β-, and γ-Proteobacteria were identified. The data suggest that numerous bacteria are capable of incorporating N from ring- and nitro-groups in RDX during anaerobic bioremediation, and that some genera may be involved in both C and N incorporation from RDX. - Highlights: • Cheese whey addition resulted in 28 different clones associated with RDX degradation. • The 28 clones belong to Bacteroidia, Bacilli, and α-, β-, and γ-Proteobacteria. • SIP identified 15 clones using RDX and/or its metabolites as a nitrogen source. • The clones clustered in Clostridia, β-Proteobacteria, and Spirochaetes.

Accumulation of mercury and methylmercury by mushrooms and earthworms from forest soils

International Nuclear Information System (INIS)

Rieder, Stephan R.; Brunner, Ivano; Horvat, Milena; Jacobs, Anna; Frey, Beat

2011-01-01

Accumulation of total and methyl-Hg by mushrooms and earthworms was studied in thirty-four natural forest soils strongly varying in soil physico-chemical characteristics. Tissue Hg concentrations of both receptors did hardly correlate with Hg concentrations in soil. Both total and methyl-Hg concentrations in tissues were species-specific and dependent on the ecological groups of receptor. Methyl-Hg was low accounting for less than 5 and 8% of total Hg in tissues of mushrooms and earthworms, respectively, but with four times higher concentrations in earthworms than mushrooms. Total Hg concentrations in mushrooms averaged 0.96 mg Hg kg -1 dw whereas litter decomposing mushrooms showed highest total Hg and methyl-Hg concentrations. Earthworms contained similar Hg concentrations (1.04 mg Hg kg -1 dw) whereas endogeic earthworms accumulated highest amounts of Hg and methyl-Hg. - Highlights: → Hg and MeHg concentrations in mushrooms and earthworms at unpolluted forest soils. → Mushrooms and earthworms contained similar Hg concentrations. → MeHg was present in traces but four times higher in earthworms than in mushrooms. → Ecophysiological group influenced Hg and MeHg concentration in both receptors. - Accumulation of Hg and methyl-Hg by mushrooms and earthworms is species- and ecophysiological group dependent.

Accumulation of mercury and methylmercury by mushrooms and earthworms from forest soils

Energy Technology Data Exchange (ETDEWEB)

Rieder, Stephan R. [Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf (Switzerland); Institute for Biogeochemistry and Pollutant Dynamics, ETH Zuerich, 8092 Zuerich (Switzerland); Brunner, Ivano [Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf (Switzerland); Horvat, Milena [Jozef Stefan Institute, 1001 Ljubliana (Slovenia); Jacobs, Anna [Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf (Switzerland); Department of Environmental Chemistry, University of Kassel, 37213 Witzenhausen (Germany); Frey, Beat, E-mail: beat.frey@wsl.ch [Rhizosphere Processes Group, Swiss Federal Research Institute WSL, 8903 Birmensdorf (Switzerland)

2011-10-15

Accumulation of total and methyl-Hg by mushrooms and earthworms was studied in thirty-four natural forest soils strongly varying in soil physico-chemical characteristics. Tissue Hg concentrations of both receptors did hardly correlate with Hg concentrations in soil. Both total and methyl-Hg concentrations in tissues were species-specific and dependent on the ecological groups of receptor. Methyl-Hg was low accounting for less than 5 and 8% of total Hg in tissues of mushrooms and earthworms, respectively, but with four times higher concentrations in earthworms than mushrooms. Total Hg concentrations in mushrooms averaged 0.96 mg Hg kg{sup -1} dw whereas litter decomposing mushrooms showed highest total Hg and methyl-Hg concentrations. Earthworms contained similar Hg concentrations (1.04 mg Hg kg{sup -1} dw) whereas endogeic earthworms accumulated highest amounts of Hg and methyl-Hg. - Highlights: > Hg and MeHg concentrations in mushrooms and earthworms at unpolluted forest soils. > Mushrooms and earthworms contained similar Hg concentrations. > MeHg was present in traces but four times higher in earthworms than in mushrooms. > Ecophysiological group influenced Hg and MeHg concentration in both receptors. - Accumulation of Hg and methyl-Hg by mushrooms and earthworms is species- and ecophysiological group dependent.

Dioxin-like chemicals in soil and sediment from residential and industrial areas in central South Africa.

Science.gov (United States)

Nieuwoudt, Claudine; Quinn, Laura P; Pieters, Rialet; Jordaan, Ilse; Visser, Maret; Kylin, Henrik; Borgen, Anders R; Giesy, John P; Bouwman, Henk

2009-08-01

Persistent organic pollutants (POPs) are a global concern due to their ubiquitous presence and toxicity. Currently, there is a lack of information regarding POPs from South Africa. Here we report and interpret concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), -dibenzofurans (PCDFs) and co-planar-biphenyls (PCBs) in soils and sediments collected from central South Africa. High resolution gas chromatography-high resolution mass spectrometry (HRGC/HRMS) and the H4IIE-luc bio-assay were used to identify and quantify individual PCDD/F congeners and to report the total concentration of 2,3,7,8-tetrachloro dibenzo-p-dioxin equivalents (TCDD-EQ), respectively. TCDD-EQs determined by use of the bio-assay, and concentrations of WHO(2005)-TEQ (toxic equivalents) determined by chemical analysis, were similar. The limit of detection (LOD) for the bio-assay was 0.82 and 2.8 ng TCDD-EQ kg(-1), dw for sediment and soil, respectively. EQ20 concentrations determined by use of the bio-assay ranged from industrial area of Vanderbijlpark and the residential area of Klerksdorp contained the greatest concentrations. Based on the congener-specific HRGC/HRMS analyzes, concentrations of WHO(2005)-TEQ ranged from 0.12 to 32 ng WHO(2005)-TEQ kg(-1), dw in sediments, and between 0.34 and 20 ng WHO(2005)-TEQkg(-1), dw in soils. The sources, processes and threats that govern and are associated with the lesser concentrations in sediment and greater concentrations in soils need further investigation.

Concentrations of persistent organic pollutants (POPs) and heavy metals in soil from San Luis Potosí, México.

Science.gov (United States)

Perez-Vazquez, Francisco Javier; Flores-Ramirez, Rogelio; Ochoa-Martinez, Angeles Catalina; Orta-Garcia, Sandra Teresa; Hernandez-Castro, Berenice; Carrizalez-Yañez, Leticia; Pérez-Maldonado, Iván N

2015-01-01

The aim of this study was to assess the levels of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), and four heavy metals (arsenic, cadmium, lead, and mercury) in soil from the city of San Luis Potosí in Mexico. In order to confirm the presence of the previously mentioned compounds, outdoor surface soil samples were collected and analyzed by gas chromatography/mass spectrometer for PBDEs, PCBs, DDT, and DDE. Meanwhile, heavy metals were quantified using the atomic absorption spectrophotometry technique. The total PBDEs levels ranged from 5.0 to 134 μg/kg dry weight (dw), with a total mean PBDEs level of 22.0 ± 32.5 μg/kg dw (geometric mean ± standard deviation). For PCBs, the total mean level in the studied soil was 21.6 ± 24.7 μg/kg dw (range, Luis Potosí, Mexico, and considering that soil is an important pathway of exposure for people, a biomonitoring program for the surveillance of the general population in the city of San Luis Potosi is necessary.

IRIS Toxicological Review of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (RDX) (External Review Draft)

Science.gov (United States)

The IRIS Toxicological Review of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was released for external peer review in September 2016. The EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis suppor...

New Approaches to Evaluate the Biological Degradation of RDX in Groundwater

Science.gov (United States)

2014-08-27

again indicate the diversity of active microorganisms associated with RDX biodegradation in the environmental samples. When cheese whey was absent...34  2.2 Task 2 – Geochemical and Environmental Conditions Affecting RDX Biodegradation ............ 36  2.2.1 Objective...Degrading Microorganisms . 49  2.3.1 Objective

A comparison of the dietary arsenic exposures from ingestion of contaminated soil and hyperaccumulating Pteris ferns used in a residential phytoremediation project.

Science.gov (United States)

Ebbs, Stephen; Hatfield, Sarah; Nagarajan, Vinay; Blaylock, Michael

2010-01-01

Arsenic (As) hyperaccumulating ferns are used to phytoremediate As-contaminated soils, including soils in residential areas. This use may pose a health risk if children were to ingest these plants. Spider brake (Pteris cretica L.) plants were grown in sand spiked with arsenate, to produce tissue As concentrations (2000-4500 mg kg DW(-1)) typical of those observed in plants deployed for As phytoremediation. The fronds were subjected to a physiologically-based extraction test to estimate As bioaccessibility, which ranged from 3.4-20.5%. A scenario for human dietary exposure to As in an urban setting was then estimated for a child consuming 0.25 g DW of tissue. The calculation of dietary exposure took into account the As concentration in the fern pinnae, the bioaccessibility of As in the tissue, and the typical absorption of inorganic As by the gastrointestinal tract. The pinnae As concentrations and the calculated dietary exposures were used to create a non-linear regression model relating tissue As concentration to dietary exposure. Data from a phytoremediation project in a residential area using Pteris cretica and Pteris vittata (L.) were input into this model to project dietary As exposure in a residential phytoremediation setting. These exposures were compared to estimates of dietary As exposure from the consumption of soil. The results showed that dietary exposures to As from consumption of soil or pinnae tissue were similar and that estimates of dietary exposure were below the LOAEL value of 14 microg As kg(-1) d(-1). The results suggest that the hyperaccumulation of As in Pteris ferns during growth in moderately contaminated residential soils (e.g., < or = 100 mg As kg DW(-1)) does not represent an inherent risk or a risk substantially different from that posed by accidental ingestion of contaminated soil.

Effects of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites on cricket (Acheta domesticus) survival and reproductive success

Energy Technology Data Exchange (ETDEWEB)

Zhang Baohong [Institute of Environmental and Human Health (TIEHH), and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States); Freitag, Christina M. [Institute of Environmental and Human Health (TIEHH), and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States); Canas, Jaclyn E. [Institute of Environmental and Human Health (TIEHH), and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States); Cheng Qiuqiong [Institute of Environmental and Human Health (TIEHH), and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States); Anderson, Todd A. [Institute of Environmental and Human Health (TIEHH), and Department of Environmental Toxicology, Texas Tech University, Box 41163, Lubbock, TX 79409-1163 (United States)]. E-mail: todd.anderson@tiehh.ttu.edu

2006-11-15

The effect of two major hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX), on cricket (Acheta domesticus) survival and reproduction was studied. RDX metabolites did not have adverse effects on cricket survival, growth, and egg production. However, MNX and TNX did affect egg hatching. MNX and TNX were more toxic in spiked-sand than in topical tests. TNX was more toxic to egg than MNX. Developmental stage and exposure time affected hatching. After 30 days exposure to MNX or TNX, the EC{sub 2}, EC{sub 5}, and EC{sub 95} were 47, 128, and 247 {mu}g/g for TNX, and 65, 140, and 253 {mu}g/g for MNX in topical tests. The ECs for 20, 50, and 95 were 21, 52, and 99 {mu}g/g for MNX, and 12, 48, and 97 {mu}g/g for TNX in sand. No gross abnormalities in cricket nypmhs were observed in all experiments indicating that neither TNX or MNX is teratogenic in this assay. - RDX metabolites did not have adverse effects on cricket survival, growth, and egg production, but adversely affected egg hatching.

Effects of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites on cricket (Acheta domesticus) survival and reproductive success

International Nuclear Information System (INIS)

Zhang Baohong; Freitag, Christina M.; Canas, Jaclyn E.; Cheng Qiuqiong; Anderson, Todd A.

2006-01-01

The effect of two major hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites, hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX), on cricket (Acheta domesticus) survival and reproduction was studied. RDX metabolites did not have adverse effects on cricket survival, growth, and egg production. However, MNX and TNX did affect egg hatching. MNX and TNX were more toxic in spiked-sand than in topical tests. TNX was more toxic to egg than MNX. Developmental stage and exposure time affected hatching. After 30 days exposure to MNX or TNX, the EC 2 , EC 5 , and EC 95 were 47, 128, and 247 μg/g for TNX, and 65, 140, and 253 μg/g for MNX in topical tests. The ECs for 20, 50, and 95 were 21, 52, and 99 μg/g for MNX, and 12, 48, and 97 μg/g for TNX in sand. No gross abnormalities in cricket nypmhs were observed in all experiments indicating that neither TNX or MNX is teratogenic in this assay. - RDX metabolites did not have adverse effects on cricket survival, growth, and egg production, but adversely affected egg hatching

Effect of Long-Term Zinc Pollution on Soil Microbial Community Resistance to Repeated Contamination

OpenAIRE

Klimek, Beata

2012-01-01

The aim of the study was to compare the effects of stress (contamination trials) on the microorganisms in zinc-polluted soil (5,018 mg Zn kg−1 soil dry weight) and unpolluted soil (141 mg Zn kg−1 soil dw), measured as soil respiration rate. In the laboratory, soils were subjected to copper contamination (0, 500, 1,500 and 4,500 mg kg−1 soil dw), and then a bactericide (oxytetracycline) combined with a fungicide (captan) along with glucose (10 mg g−1 soil dw each) were added. There was a highl...

Deafness and permanently reduced potassium channel gene expression and function in hypothyroid Pit1dw mutants

Science.gov (United States)

Mustapha, Mirna; Fang, Qing; Gong, Tzy-Wen; Dolan, David F.; Raphael, Yehoash; Camper, Sally A.; Duncan, R. Keith

2012-01-01

The absence of thyroid hormone (TH) during late gestation and early infancy can cause irreparable deafness in both humans and rodents. A variety of rodent models have been utilized in an effort to identify the underlying molecular mechanism. Here, we characterize a mouse model of secondary hypothyroidism, pituitary transcription factor 1 (Pit1dw), which has profound, congenital deafness that is rescued by oral TH replacement. These mutants have tectorial membrane abnormalities, including a prominent Hensen's stripe, elevated β-tectorin composition, and disrupted striated-sheet matrix. They lack distortion product otoacoustic emissions and cochlear microphonic responses, and exhibit reduced endocochlear potentials, suggesting defects in outer hair cell function and potassium recycling. Auditory system and hair cell physiology, histology and anatomy studies reveal novel defects of hormone deficiency related to deafness: (1) permanently impaired expression of KCNJ10 in the stria vascularis of Pit1dw mice, which likely contributes to the reduced endocochlear potential, (2) significant outer hair cell loss in the mutants, which may result from cellular stress induced by the lower KCNQ4 expression and current levels in Pit1dw mutant outer hair cells and (3) sensory and strial cell deterioration, which may have implications for thyroid hormone dysregulation in age related hearing impairment. In summary, we suggest that these defects in outer hair cell and strial cell function are important contributors to the hearing impairment in Pit1dw mice. PMID:19176829

The effects of carbon sources and micronutrients in whey and fermented whey on the kinetics of phenanthrene biodegradation in diesel contaminated soil

International Nuclear Information System (INIS)

Jonsson, Anders P.; Ostberg, Tomas L.

2011-01-01

Highlights: · Whey and fermented whey significantly enhances phenanthrene biodegradation. · Mode of administration and amount of amendment is decisive. · Observed effects were increased linear growth, bioavailability and degradation. · The effects were attributed to lactate and vitamins. · Growth factors play a significant role in phenanthrene biodegradation. - Abstract: This paper demonstrates significant effects on phenanthrene degradation in diesel contaminated soil by the addition of organic amendments such as whey and fermented whey. Both amount of amendment added and mode of administration was shown to be decisive. There was a strong positive effect on the 14 C-mineralization of phenanthrene by multiple (bi-weekly) additions of fermented whey 210 mg dw kg -1 soil dw (FW multi) and also by single dose addition of 2100 mg dw sweet whey kg -1 soil dw (SW high). The most prominent effects on phenanthrene degradation kinetics were a five to fifteen fold increase in the linear growth term (k 2 ) and a 23-27% increase in bioavailability factor S 0 for SW high and FW multi respectively. Also, total mineralization at the end of the experiment increased from 46% in the control to 66 and 71% respectively and the lag time was reduced from 21 to 15 days by multiple addition of fermented whey. The most significant stimulating effects on phenanthrene degradation kinetics could be attributed to lactate and vitamins. This study demonstrates a more complex dependence of carbon sources and growth factors for an aromatic compound such as phenanthrene in comparison to hexadecane.

The effects of carbon sources and micronutrients in whey and fermented whey on the kinetics of phenanthrene biodegradation in diesel contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Jonsson, Anders P., E-mail: anders.jonsson@miun.se [Department of Engineering, and Sustainable Development, Mid Sweden University, SE-83125 Ostersund (Sweden); Ostberg, Tomas L. [Jegrelius Institute for Applied Green Chemistry, Studiegangen 3, SE-831 40 Ostersund (Sweden)

2011-09-15

Highlights: {center_dot} Whey and fermented whey significantly enhances phenanthrene biodegradation. {center_dot} Mode of administration and amount of amendment is decisive. {center_dot} Observed effects were increased linear growth, bioavailability and degradation. {center_dot} The effects were attributed to lactate and vitamins. {center_dot} Growth factors play a significant role in phenanthrene biodegradation. - Abstract: This paper demonstrates significant effects on phenanthrene degradation in diesel contaminated soil by the addition of organic amendments such as whey and fermented whey. Both amount of amendment added and mode of administration was shown to be decisive. There was a strong positive effect on the {sup 14}C-mineralization of phenanthrene by multiple (bi-weekly) additions of fermented whey 210 mg dw kg{sup -1} soil dw (FW multi) and also by single dose addition of 2100 mg dw sweet whey kg{sup -1} soil dw (SW high). The most prominent effects on phenanthrene degradation kinetics were a five to fifteen fold increase in the linear growth term (k{sub 2}) and a 23-27% increase in bioavailability factor S{sub 0} for SW high and FW multi respectively. Also, total mineralization at the end of the experiment increased from 46% in the control to 66 and 71% respectively and the lag time was reduced from 21 to 15 days by multiple addition of fermented whey. The most significant stimulating effects on phenanthrene degradation kinetics could be attributed to lactate and vitamins. This study demonstrates a more complex dependence of carbon sources and growth factors for an aromatic compound such as phenanthrene in comparison to hexadecane.

Feasibility of In Situ Redox Manipulation of Subsurface Sediments for RDX Remediation at Pantex

Energy Technology Data Exchange (ETDEWEB)

Szecsody, James E.; Fruchter, Jonathan S.; Mckinley, Mark A.; Resch, Charles T.; Gilmore, Tyler J.

2001-12-31

This laboratory study was conducted to assess RDX (hexahydro-1,3,5-trinitro-1,3,5 triazine) abiotic degradation by chemically reduced sediments and other geochemical aspects of the application of this technology to remediation of RDX contamination in groundwater at the U.S. DOE Pantex facility...

Characterization of the Morphology of RDX Particles Formed by Laser Ablation

Science.gov (United States)

2012-02-01

military-grade RDX can contain significant amounts of HMX (up to 5% for type-I RDX produced by direct nitration with the Woolwich process and up to...potentially produce RDX particles with specific morphologies in support of microstructural experiments for the Multiscale Response of Energetic

Residues of Organochlorinated Pesticides in Soil from Tomato ...

African Journals Online (AJOL)

This work presents the concentrations of five pesticide residues, lindane, chlorpyrifos, endosulfan, p, p'-DDE and p, p'-DDD in soil samples collected from tomato fields in Ngarenanyuki, Tanzania. Endosulfan sulphate was detected in 100 % of the sample analysed with mean concentration of 0.2407 mg/kg dw. Chlorpyrifos ...

Chelant-assisted phytoextraction and accumulation of Zn by Zea mays.

Science.gov (United States)

Gheju, M; Stelescu, I

2013-10-15

Zea mays plants were exposed to soils with concentrations of Zn ranging from 64 to 1800 mg kg(-1) dw, and the efficiency of three selected chelating agents (trisodium citrate (CI), disodium oxalate (OX) and disodium dihydrogen ethylene-diamine-tetraacetate (EDTA)) in enhancing metal phytoextraction was compared. Zn concentration in plant tissues increased in conjunction with the metal concentration of the soil. EDTA was found to be the most efficient chelating amendment, increasing concentrations of Zn in shoots from 88 mg kg(-1) dw, at 64 mg kg(-1) dw soil, to 8026 mg kg(-1) dw at 1800 mg kg(-1) dw soil. The overall orders of BCFs and TFs which resulted from this study are: EDTA > H2O > OX > CI, and EDTANa2 > OX > CI > H2O, respectively. The more effective uptake of Zn by plants for the control treatment (distilled water only) than for CI and OX was attributed to the neutral or slightly alkaline pH of the two chelant irrigation solutions. Instead, EDTA had a favorable effect on Zn uptake from soil due to its additive chelating and acidifying properties. Among the three chelants, only EDTA significantly increased the Zn phytoextraction potential of Z. mays, while CI and OX induced a low metal uptake from soil by plants. Although Z. mays has a lower Zn accumulation capacity than the hyperaccumulator Thlaspi caerulescens, it could be considered as a potential phytoremediator of soils with elevated Zn concentrations, especially when metal pollution extends to depths greater than 20 cm. Copyright © 2013 Elsevier Ltd. All rights reserved.

Occurrence of veterinary antibiotics and progesterone in broiler manure and agricultural soil in Malaysia.

Science.gov (United States)

Ho, Yu Bin; Zakaria, Mohamad Pauzi; Latif, Puziah Abdul; Saari, Nazamid

2014-08-01

Repeated applications of animal manure as fertilizer are normal agricultural practices that may release veterinary antibiotics and hormones into the environment from treated animals. Broiler manure samples and their respective manure-amended agricultural soil samples were collected in selected locations in the states of Selangor, Negeri Sembilan and Melaka in Malaysia to identify and quantify veterinary antibiotic and hormone residues in the environment. The samples were analyzed using ultrasonic extraction followed by solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The broiler manure samples were found to be contaminated with at least six target analytes, namely, doxycycline, enrofloxacin, flumequine, norfloxacin, trimethoprim and tylosin. These analytes were detected in broiler manure samples with maximum concentrations reaching up to 78,516 μg kg(-1) dry weight (DW) (doxycycline). For manure-amended agricultural soil samples, doxycycline and enrofloxacin residues were detected in every soil sample. The maximum concentration of antibiotic detected in soil was 1331 μg kg(-1) DW (flumequine). The occurrence of antibiotics and hormones in animal manure at high concentration poses a risk of contaminating agricultural soil via fertilization with animal manure. Some physico-chemical parameters such as pH, total organic carbon (TOC) and metal content played a considerable role in the fate of the target veterinary antibiotics and progesterone in the environment. It was suggested that these parameters can affect the adsorption of pharmaceuticals to solid environmental matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

Functional EIAO DW, R2.2

DEFF Research Database (Denmark)

Thomsen, Christian; Pedersen, Torben Bach; Frøkjær, Jens

In this document, the functional specification and architecture for the EIAO DW is presented. EIAO DW is a data warehouse that holds results from the European Internet Accessibility Observatory (EIAO) project. These results are mainly on the accessibility to disabled users of web resources...

Human health risks from TNT, RDX, and HMX in environmental media and consideration of the US Regulatory Environment

International Nuclear Information System (INIS)

Daniels, J.I.; Knezovich, J.P.

1994-12-01

Although the most economical method for disposing of unwanted energetic high explosives [HEs; e.g., 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-triazine (RDX, also known as Cyclonite), and octahydro-1,3,5,7-tetrazocine (HMX, also known as Octogen)] involves open burning and open or underground detonation [OB/O(U)D]; federal, state, and even local government agencies in the United States (U.S.) are implementing stricter environmental regulations that eventually may prevent such activities. These stricter regulations will promote alternative technologies that are designed to be environmentally benign. However, past HE-waste disposal practices at manufacturing and fabrication facilities in the U.S. have included uncontrolled OB/O(U)D, as well as direct surface discharge of HE-contaminated waste water, resulting in contaminated environmental media (e.g., ground water, soil, and perhaps even edible vegetation) near residential areas. Using TNT, RDX, and HMX as examples, this paper describes how risk-based standards for HEs can be derived that account for potential multimedia exposures (associated with contaminated air, water, food, and soil) by individuals near a contaminated site, and used to (1) protect public health and safety; (2)prevent limited resources from being dedicated to unnecessary cleanup activities; and (3) identify the most cost-effective, practical, and environmentally benign technologies suitable for integrating with the handling of the large quantity of high explosives scheduled for demilitarization

Mercury emission and distribution: Potential environmental risks at a small-scale gold mining operation, Phichit Province, Thailand.

Science.gov (United States)

Pataranawat, Poranee; Parkpian, Preeda; Polprasert, Chongrak; Delaune, R D; Jugsujinda, A

2007-07-01

Mercury (Hg) contamination was assessed in environment near an amalgamation gold recovery operation located at a small scale mining operation (Phanom Pha) in Phichit Province, Thailand. Total mercury (THg) concentrations was determined in water, sediment, bivalves in the aquatic environment and as dry deposition or atmospheric fallout on surface soil and leaves of Neem tree (Azadirachta indica Juss. var. siamensis Valeton) near the mining operation. THg in surface soil, Neem flowers (edible part) and rice grain in surrounding terrestrial habitat and with distance from the mining area were also evaluated for possible contamination. Potential environmental risks were evaluated using the hazard quotient equation. Hg analyses conducted in the aquatic habitat showed that THg in water, sediment and bivalves (Scabies cripata Gould) ranged from 0.4 to 4 microg L(-1), 96 to 402 microg kg(-1)dry weight (dw) and 15 to 584 microg kg(-1) wet weight (ww), respectively. High concentrations of THg in water, sediment and bivalves were observed in the receiving stream near the mining operation which was located near the Khao Chet Luk Reservoir. Whereas the THg concentration in water, sediment and bivalves from monitoring stations outside the gold mining operation (upstream and downstream), were considerably lower with the values of 0.4-0.8 microg L(-1), 96-140 microg kg(-1) dw and 88-658 microg kg(-1) dw, respectively. The elevated concentration of Hg found in the sediment near the mining operation was consistent with Hg accumulation measured in bivalves. The elevated Hg levels found in living bivalves collected from highly contaminated sites suggested that the sediment bound Hg was bioavailable. THg in surface soils, brown rice grain (Jasmine rice #105) and Neem flowers of terrestrial habitats were in the range of 16 to 180 microg kg(-1) dw, 190 to 300 microg kg(-1) dw, and 622 to 2150 microg kg(-1) dw, respectively. Elevated concentrations of mercury were found in Neem flowers

Cs phytoremediation by Sorghum bicolor cultivated in soil and in hydroponic system.

Science.gov (United States)

Wang, Xu; Chen, Can; Wang, Jianlong

2017-04-03

Cs accumulation characteristics by Sorghum bicolor were investigated in hydroponic system (Cs level at 50-1000 μmol/L) and in soil (Cs-spiked concentration was 100 and 400 mg/kg soil). Two varieties of S. bicolor Cowly and Nengsi 2# grown on pot soil during the entire growth period (100 days) did not show significant differences on the height, dry weight (DW), and Cs accumulation. S. bicolor showed the potential phytoextraction ability for Cs-contaminated soil with the bioaccumulation factor (BCF) and the translocation factor (TF) values usually higher than 1 in soil system and in hydroponic system. The aerial parts of S. bicolor contributed to 86-92% of the total removed amounts of Cs from soil. Cs level in solution at 100 μmol/L gave the highest BCF and TF values of S. bicolor. Cs at low level tended to transfer to the aerial parts, whereas Cs at high level decreased the transfer ratio from root to shoot. In soil, the plant grew well when Cs spiked level was 100 mg/kg soil, but was inhibited by Cs at 400 mg/kg soil with Cs content in sorghum reaching 1147 mg/kg (roots), 2473 mg/kg (stems), and 2939 mg/kg (leaves). In hydroponic system, average Cs level in sorghum reached 5270 mg/kg (roots) and 4513 mg/kg (aerial parts), without significant damages to its biomass at 30 days after starting Cs treatment. Cs accumulation in sorghum tissues was positively correlated with the metal concentration in medium.

RDX Detection with THz Spectroscopy

Science.gov (United States)

Michalopoulou, Zoi-Heleni; Mukherjee, Suman; Hor, Yew Li; Su, Ke; Liu, Zhiwei; Barat, Robert B.; Gary, Dale E.; Federici, John F.

2010-10-01

Spectroscopic analysis in the Terahertz frequency range, providing characteristic “signatures” for explosive and non-explosive materials, is proposed as an efficient and powerful tool for explosive identification. It is demonstrated that spectral responses of materials can be used as fingerprints that distinguish cyclotrimethylenetrinitramine (RDX) from other materials even with simple detectors and a limited number of available frequencies. Detection is performed using a modified least squares approach and multilayer perceptrons that operate on smoothed reflectance spectra. The performance of the detectors is evaluated through application to spectra of RDX and several common materials. A Receiver Operating Characteristic curve analysis demonstrates that our detectors exhibit the desirable properties of high probability of detection and low probability of false alarm.

Clostridium geopurificans strain MJ1 sp. nov., a strictly anaerobic bacterium that grows via fermentation and reduces the cyclic nitramine explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX).

Science.gov (United States)

Kwon, Man Jae; Wei, Na; Millerick, Kayleigh; Popovic, Jovan; Finneran, Kevin

2014-06-01

A fermentative, non-spore forming, motile, rod-shaped bacterium, designated strain MJ1(T), was isolated from an RDX contaminated aquifer at a live-fire training site in Northwest NJ, United States. On the basis of 16S rRNA gene sequencing and DNA base composition, strain MJ1(T) was assigned to the Firmicutes. The DNA G+C content was 42.8 mol%. Fermentative growth was supported by glucose and citrate in a defined basal medium. The bacterium is a strict anaerobe that grows between at pH 6.0 and pH 8.0 and 18 and 37 °C. The culture did not grow with hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) as the electron acceptor or mineralize RDX under these conditions. However, MJ1(T) transformed RDX into MNX, methylenedinitramine, formaldehyde, formate, ammonium, nitrous oxide, and nitrate. The nearest phylogenetic relative with a validly published name was Desulfotomaculum guttoideum (95 % similarity). However, MJ1(T) was also related to Clostridium celerecrescens DSM 5628 (95 %), Clostridium indolis DSM 755 (94 %), and Clostridium sphenoides DSM 632 (94 %). DNA:DNA hybridization with these strains was between 6.7 and 58.7 percent. The dominant cellular fatty acids (greater than 5 % of the total, which was 99.0 % recovery) were 16:0 fatty acid methyl ester (FAME) (32.12 %), 18:1cis 11 dimethyl acetal (DMA) (16.47 %), 16:1cis 9 DMA (10.28 %), 16:1cis 9 FAME (8.10 %), and 18:1cis 9 DMA (5.36 %). On the basis of morphological, physiological, and phylogenetic data, Clostridium geopurificans is proposed as a new species in genus Clostridium, with strain MJ1(T) as the type strain.

Cadmium contamination in orchard soils and fruit trees and its potential health risk in Guangzhou, China.

Science.gov (United States)

Li, J T; Qiu, J W; Wang, X W; Zhong, Y; Lan, C Y; Shu, W S

2006-09-01

This study examines cadmium (Cd) contamination in orchard soils and fruit trees in Guangzhou, China, and assesses its potential health risk. Soils and tissues samples of three species of fruit trees were collected from three orchards. The average soil Cd concentration was 1.27, 1.84 and 0.68 mg/kg in orchards I, II, and III, respectively. The carambola (Averrhoa carambola) accumulated exceptionally high concentrations of Cd (7.57, 10.84, 9.01 and 2.15 mg/kg dw in root, twig, leaf and fruit, respectively), being 6.0-24 times and 4.0-10 times the corresponding tissue Cd in the longan (Dimocarpus longan) and wampee (Clausena lansium), respectively. Furthermore, all Cd concentrations (0.04-0.25 mg Cd/kg fw) of the fruits exceeded the tolerance limit of cadmium in foods of PR China (0.03 mg/kg fw). Our results indicate that the carambola tree has high Cd accumulation capacity and might be a Cd accumulator; and its fruit, among the three species of fruits studied, also poses the highest potential health risk to local residents.

Verification of RDX Photolysis Mechanism

National Research Council Canada - National Science Library

Peyton, Gary

1999-01-01

... such as formaldehyde and formic acid, as well as the inorganic ions nitrate and nitrite. This implies that UV photolysis might provide a satisfactory and economical treatment system for RDX in water...

The effects of the insecticide lambda-Cyhalothrin on the earthworm Eisenia fetida under experimental conditions of tropical and temperate regions.

Science.gov (United States)

Garcia, Marcos; Scheffczyk, Adam; Garcia, Terezinha; Römbke, Jörg

2011-02-01

Plant Protection Products can affect soil organisms and thus might have negative impacts on soil functions. Little research has been performed on their impact on tropical soils. Therefore, the effects of the insecticide lambda-Cyhalothrin on earthworms were evaluated in acute and chronic laboratory tests modified for tropical conditions, i.e. at selected temperatures (20 and 28°C) and with two strains (temperate and tropical) of the compost worm Eisenia fetida. The insecticide was spiked in two natural soils, in OECD artificial soil and a newly developed tropical artificial soil. The effects of lambda-Cyhalothrin did rarely vary in the same soil at tropical (LC50: 68.5-229 mg a.i./kg dry weight (DW); EC50: 54.2-60.2 mg a.i./kg DW) and temperate (LC50: 99.8-140 mg a.i./kg DW; EC50: 37.4-44.5 mg a.i./kg DW) temperatures. In tests with tropical soils and high temperature, effect values differed by up to a factor of ten. Copyright © 2010 Elsevier Ltd. All rights reserved.

Modeling Nonlinear Elastic-plastic Behavior of RDX Single Crystals During Indentation

Science.gov (United States)

2012-01-01

single crystals has also been probed using shock experiments (6, 12) and molecular dynamics simulations (12–14). RDX undergoes a polymorphic phase...Patterson, J.; Dreger, Z.; Gupta, Y. Shock-wave Induced Phase Transition in RDX Single Crystals. J. Phys. Chem. B 2007, 111, 10897–10904. 17. Bedrov, D...and Volume Compression of β - HMX and RDX . In Proc. Int. Symp. High Dynamic Pressures; Commissariat a l’Energie Atomique: Paris, 1978; pp 3–8. 24

Integrated Data Collection Analysis (IDCA) Program - RDX Standard Data Set 2

Energy Technology Data Exchange (ETDEWEB)

Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Phillips, Jason J. [Air Force Research Lab. (AFRL), Tyndall Air Force Base, FL (United States); Shelley, Timothy J. [Applied Research Associates, Tyndall Air Force Base, FL (United States); Reyes, Jose A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-02-20

The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of the RDX Type II Class 5 standard, from testing the second time in the Proficiency Test. This RDX testing (Set 2) compared to the first (Set 1) was found to have about the same impact sensitivity, have more BAM friction sensitivity, less ABL friction sensitivity, similar ESD sensitivity, and same DSC sensitivity.

Pig manure vermicompost (PMVC) can improve phytoremediation of Cd and PAHs co-contaminated soil by Sedum alfredii

Energy Technology Data Exchange (ETDEWEB)

Wang, Kai; Zhang, Jie; Huang, Huagang; Li, Tingqiang; Yang, Xiaoe [Zhejiang Univ., Hangzhou (China). MOE Key Laboratory of Environment Remediation and Ecosystem Health; Zhu, Zhiqiang [Zhejiang Univ., Hangzhou (China). MOE Key Laboratory of Environment Remediation and Ecosystem Health; Hainan Univ., Haikou (China). College of Agriculture; He, Zehnli [Florida Univ., Fort Pierce (United States). Indian River Research and Education Center; Alva, Ashok [U.S. Department of Agriculture, Prosser, WA (United States). Agricultural Research Service

2012-08-15

Purpose: A major challenge to phytoremediation of co-contaminated soils is developing strategies for efficient and simultaneous removal of multiple pollutants. A pot experiment was conducted to investigate the potential for enhanced phytoextraction of cadmium (Cd) by Sedum alfredii and dissipation of polycyclic aromatic hydrocarbons (PAHs) in co-contaminated soil by application of pig manure vermicompost (PMVC). Materials and methods: Soil contaminated by Cd (5.53 mg kg{sup -1} DW) was spiked with phenanthrene, anthracene, and pyrene together (250 mg kg{sup -1} DW for each PAH). A pot experiment was conducted in a greenhouse with four treatments: (1) soil without plants and PMVC (Control), (2) soil planted with S. alfredii (Plant), (3) soil amended with PMVC at 5 % (w/w) (PMVC), and (4) treatment 2 + 3 (Plant + PMVC). After 90 days, shoot and root biomass of plants, Cd concentrations in plant and soil, and PAH concentrations in soil were determined. Abundance of PAH degraders in soil, soil bacterial community structure and diversity, and soil enzyme activities and microbial biomass carbon were measured. Results and discussion: Application of PMVC to co-contaminated soil increased the shoot and root dry biomass of S. alfredii by 2.27- and 3.93-fold, respectively, and simultaneously increased Cd phytoextraction without inhibiting soil microbial population and enzyme activities. The highest dissipation rate of PAHs was observed in Plant + PMVC treatment. However, neither S. alfredii nor PMVC enhanced PAH dissipation when applied separately. Abundance of PAH degraders in soil was not significantly related to PAH dissipation rate. Plant + PMVC treatment significantly influenced the bacterial community structure. Enhanced PAH dissipation in the Plant + PMVC treatment could be due to the improvement of plant root growth, which may result in increased root exudates, and subsequently change bacterial community structure to be favorable for PAH dissipation. Conclusions: This

Chronic toxicity of ZnO nanoparticles, non-nano ZnO and ZnCl2 to Folsomia candida (Collembola) in relation to bioavailability in soil

International Nuclear Information System (INIS)

Kool, Pauline L.; Diez Ortiz, Maria; Gestel, Cornelis A.M. van

2011-01-01

The chronic toxicity of zinc oxide nanoparticles (ZnO-NP) to Folsomia candida was determined in natural soil. To unravel the contribution of particle size and free zinc to NP toxicity, non-nano ZnO and ZnCl 2 were also tested. Zinc concentrations in pore water increased with increasing soil concentrations, with Freundlich sorption constants K f of 61.7, 106 and 96.4 l/kg (n = 1.50, 1.34 and 0.42) for ZnO-NP, non-nano ZnO and ZnCl 2 respectively. Survival of F. candida was not affected by ZnO-NP and non-nano ZnO at concentrations up to 6400 mg Zn/kg d.w. Reproduction was dose-dependently reduced with 28-d EC50s of 1964, 1591 and 298 mg Zn/kg d.w. for ZnO-NP, non-nano ZnO and ZnCl 2 , respectively. The difference in EC50s based on measured pore water concentrations was small (7.94-16.8 mg Zn/l). We conclude that zinc ions released from NP determine the observed toxic effects rather than ZnO particle size. - Highlights: → ZnO nanoparticles and non-nano ZnO were equally toxic to Folsomia candida in soil. → Pore water from soil spiked with ZnO nanoparticles showed saturation with zinc suggesting aggregation. → Pore water based EC50 values for ZnO nanoparticles and ZnCl 2 were similar. → ZnO nanoparticle toxicity in soil was most probably due to Zn dissolution from the nanoparticles. - ZnO nanoparticle toxicity to springtails in soil can be explained from Zn dissolution but not from particle size.

Effect of Long Term Low-Level Gamma Radiation on Thermal Sensitivity of RDX/HMX Mixtures

Science.gov (United States)

1976-11-01

1.1x10 R. It was concluded that the slight exothermic reaction before the 3^6 HMX polymorphic transition could be caused by a radiation-induced...Radiation on Thermal Sensitivity of RDX / HMX Mixtures 5. TYPE OF REPORT 4 PERIOD COVERED Final Report 6. PERFORMING ORG. REPORT NUMBER 7...and Identity by block number) Gamma radiation Weight loss HMX Impact sensitivity test RDX Vacuum stability test DTA Infrared spectrometry TGA

SoilGrids1km--global soil information based on automated mapping.

Directory of Open Access Journals (Sweden)

Tomislav Hengl

Full Text Available BACKGROUND: Soils are widely recognized as a non-renewable natural resource and as biophysical carbon sinks. As such, there is a growing requirement for global soil information. Although several global soil information systems already exist, these tend to suffer from inconsistencies and limited spatial detail. METHODOLOGY/PRINCIPAL FINDINGS: We present SoilGrids1km--a global 3D soil information system at 1 km resolution--containing spatial predictions for a selection of soil properties (at six standard depths: soil organic carbon (g kg-1, soil pH, sand, silt and clay fractions (%, bulk density (kg m-3, cation-exchange capacity (cmol+/kg, coarse fragments (%, soil organic carbon stock (t ha-1, depth to bedrock (cm, World Reference Base soil groups, and USDA Soil Taxonomy suborders. Our predictions are based on global spatial prediction models which we fitted, per soil variable, using a compilation of major international soil profile databases (ca. 110,000 soil profiles, and a selection of ca. 75 global environmental covariates representing soil forming factors. Results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices (based on MODIS images, lithology, and taxonomic mapping units derived from conventional soil survey (Harmonized World Soil Database. Prediction accuracies assessed using 5-fold cross-validation were between 23-51%. CONCLUSIONS/SIGNIFICANCE: SoilGrids1km provide an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available. Some of the main limitations of the current version of SoilGrids1km are: (1 weak relationships between soil properties/classes and explanatory variables due to scale mismatches, (2 difficulty to obtain covariates that capture soil forming factors, (3 low sampling density and spatial clustering of soil profile locations. However, as the SoilGrids system is

Total and Bioaccessible Soil Arsenic and Lead Levels and Plant Uptake in Three Urban Community Gardens in Puerto Rico

Directory of Open Access Journals (Sweden)

John Misenheimer

2018-01-01

Full Text Available Arsenic (As and lead (Pb are two contaminants of concern associated with urban gardening. In Puerto Rico, data currently is limited on As and Pb levels in urban garden soils, soil metal (loid bioaccessibility, and uptake of As and Pb in soil by edible plants grown in the region. This study examined total and bioaccessible soil As and Pb concentrations and accumulation in 10 commonly grown garden plants collected from three urban community gardens in Puerto Rico. Bioavailability values were predicted using bioaccessibility data to compare site-specific bioavailability estimates to commonly used default exposure assumptions. Total and bioaccessible As levels in study soils ranged from 2 to 55 mg/kg and 1 to 18 mg/kg, respectively. Total and bioaccessible Pb levels ranged from 19 to 172 mg/kg and 17 to 97 mg/kg, respectively. Measured bioaccessibility values corresponded to 19% to 42% bioaccessible As and 61% to 100% bioaccessible Pb when expressed as a percent of total As and Pb respectively. Predicted relative percent bioavailability of soil As and Pb based on measured bioaccessibility values ranged from 18% to 36% and 51% to 85% for As and Pb respectively. Transfer factors (TFs measuring uptake of As in plants from soil ranged from 0 to 0.073 in the edible flesh (fruit or vegetable of plant tissues analyzed and 0.073 to 0.444 in edible leaves. Pb TFs ranged from 0.002 to 0.012 in flesh and 0.023 to 0.204 in leaves. Consistent with TF values, leaves accumulated higher concentrations of As and Pb than the flesh, with the highest tissue concentrations observed in the culantro leaf (3.2 mg/kg dw of As and 8.9 mg/kg dw of Pb. Leaves showed a general but not statistically-significant (α = 0.05 trend of increased As and Pb concentration with increased soil levels, while no trend was observed for flesh tissues. These findings provide critical data that can improve accuracy and reduce uncertainty when conducting site-specific risk determination of

Chronic toxicity of ZnO nanoparticles, non-nano ZnO and ZnCl{sub 2} to Folsomia candida (Collembola) in relation to bioavailability in soil

Energy Technology Data Exchange (ETDEWEB)

Kool, Pauline L., E-mail: pauline.kool@falw.vu.nl [Department of Animal Ecology, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Diez Ortiz, Maria [Department of Animal Ecology, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Pole de Recherche ROVALTAIN en Toxicologie Environnementale et Ecotoxicologie, Batiment Rhovalparc, BP 15173, 26958 Valence Cedex 9 (France); Gestel, Cornelis A.M. van [Department of Animal Ecology, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

2011-10-15

The chronic toxicity of zinc oxide nanoparticles (ZnO-NP) to Folsomia candida was determined in natural soil. To unravel the contribution of particle size and free zinc to NP toxicity, non-nano ZnO and ZnCl{sub 2} were also tested. Zinc concentrations in pore water increased with increasing soil concentrations, with Freundlich sorption constants K{sub f} of 61.7, 106 and 96.4 l/kg (n = 1.50, 1.34 and 0.42) for ZnO-NP, non-nano ZnO and ZnCl{sub 2} respectively. Survival of F. candida was not affected by ZnO-NP and non-nano ZnO at concentrations up to 6400 mg Zn/kg d.w. Reproduction was dose-dependently reduced with 28-d EC50s of 1964, 1591 and 298 mg Zn/kg d.w. for ZnO-NP, non-nano ZnO and ZnCl{sub 2}, respectively. The difference in EC50s based on measured pore water concentrations was small (7.94-16.8 mg Zn/l). We conclude that zinc ions released from NP determine the observed toxic effects rather than ZnO particle size. - Highlights: > ZnO nanoparticles and non-nano ZnO were equally toxic to Folsomia candida in soil. > Pore water from soil spiked with ZnO nanoparticles showed saturation with zinc suggesting aggregation. > Pore water based EC50 values for ZnO nanoparticles and ZnCl{sub 2} were similar. > ZnO nanoparticle toxicity in soil was most probably due to Zn dissolution from the nanoparticles. - ZnO nanoparticle toxicity to springtails in soil can be explained from Zn dissolution but not from particle size.

IRIS Toxicological Review of Hexahydro-1,3,5-Trinitro-1,3,5-Triazine (RDX) (Preliminary Assessment Materials)

Science.gov (United States)

In August 2013, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for RDX to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA was interested in c...

Application of 13C and 15N stable isotope probing to characterize RDX degrading microbial communities under different electron-accepting conditions

International Nuclear Information System (INIS)

Cho, Kun-Ching; Lee, Do Gyun; Fuller, Mark E.; Hatzinger, Paul B.; Condee, Charles W.; Chu, Kung-Hui

2015-01-01

Highlights: • SIP characterized RDX-degrading communities under different e-accepting conditions. • Dominant RDX degradation pathways differed under different e-accepting conditions. • More complete detoxification of RDX occurred under methanogenic and sulfate-reducing conditions than under manganese(IV) and iron(III)-reducing conditions. - Abstract: This study identified microorganisms capable of using the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) or its metabolites as carbon and/or nitrogen sources under different electron-accepting conditions using 13 C and 15 N stable isotope probing (SIP). Mesocosms were constructed using groundwater and aquifer solids from an RDX-contaminated aquifer. The mesocosms received succinate as a carbon source and one of four electron acceptors (nitrate, manganese(IV), iron(III), or sulfate) or no additional electron acceptor (to stimulate methanogenesis). When RDX degradation was observed, subsamples from each mesocosm were removed and amended with 13 C 3 - or ring- 15 N 3 -, nitro- 15 N 3 -, or fully-labeled 15 N 6 -RDX, followed by additional incubation and isolation of labeled nucleic acids. A total of fifteen 16S rRNA sequences, clustering in α- and γ-Proteobacteria, Clostridia, and Actinobacteria, were detected in the 13 C-DNA fractions. A total of twenty seven sequences were derived from different 15 N-DNA fractions, with the sequences clustered in α- and γ-Proteobacteria, and Clostridia. Interestingly, sequences identified as Desulfosporosinus sp. (in the Clostridia) were not only observed to incorporate the labeled 13 C or 15 N from labeled RDX, but also were detected under each of the different electron-accepting conditions. The data suggest that 13 C- and 15 N-SIP can be used to characterize microbial communities involved in RDX biodegradation, and that the dominant pathway of RDX biodegradation may differ under different electron-accepting conditions

Cadmium contamination in orchard soils and fruit trees and its potential health risk in Guangzhou, China

International Nuclear Information System (INIS)

Li, J.T.; Qiu, J.W.; Wang, X.W.; Zhong, Y.; Lan, C.Y.; Shu, W.S.

2006-01-01

This study examines cadmium (Cd) contamination in orchard soils and fruit trees in Guangzhou, China, and assesses its potential health risk. Soils and tissues samples of three species of fruit trees were collected from three orchards. The average soil Cd concentration was 1.27, 1.84 and 0.68 mg/kg in orchards I, II, and III, respectively. The carambola (Averrhoa carambola) accumulated exceptionally high concentrations of Cd (7.57, 10.84, 9.01 and 2.15 mg/kg dw in root, twig, leaf and fruit, respectively), being 6.0-24 times and 4.0-10 times the corresponding tissue Cd in the longan (Dimocarpus longan) and wampee (Clausena lansium), respectively. Furthermore, all Cd concentrations (0.04-0.25 mg Cd/kg fw) of the fruits exceeded the tolerance limit of cadmium in foods of PR China (0.03 mg/kg fw). Our results indicate that the carambola tree has high Cd accumulation capacity and might be a Cd accumulator; and its fruit, among the three species of fruits studied, also poses the highest potential health risk to local residents. - Carambola fruit can accumulate high levels of cadmium and may be a health risk for humans

Cadmium contamination in orchard soils and fruit trees and its potential health risk in Guangzhou, China

Energy Technology Data Exchange (ETDEWEB)

Li, J.T. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Qiu, J.W. [Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong (China); Wang, X.W. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Zhong, Y. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China); Lan, C.Y. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China)]. E-mail: ls04@zsu.edu.cn; Shu, W.S. [School of Life Sciences and State Key Laboratory of Biocontrol, Sun Yat-sen (Zhongshan) University, Guangzhou 510275 (China)]. E-mail: ls53@zsu.edu.cn

2006-09-15

This study examines cadmium (Cd) contamination in orchard soils and fruit trees in Guangzhou, China, and assesses its potential health risk. Soils and tissues samples of three species of fruit trees were collected from three orchards. The average soil Cd concentration was 1.27, 1.84 and 0.68 mg/kg in orchards I, II, and III, respectively. The carambola (Averrhoa carambola) accumulated exceptionally high concentrations of Cd (7.57, 10.84, 9.01 and 2.15 mg/kg dw in root, twig, leaf and fruit, respectively), being 6.0-24 times and 4.0-10 times the corresponding tissue Cd in the longan (Dimocarpus longan) and wampee (Clausena lansium), respectively. Furthermore, all Cd concentrations (0.04-0.25 mg Cd/kg fw) of the fruits exceeded the tolerance limit of cadmium in foods of PR China (0.03 mg/kg fw). Our results indicate that the carambola tree has high Cd accumulation capacity and might be a Cd accumulator; and its fruit, among the three species of fruits studied, also poses the highest potential health risk to local residents. - Carambola fruit can accumulate high levels of cadmium and may be a health risk for humans.

Toxicity of hexahydro-1,3,5-trinitro-1,3,5-triazine to larval zebrafish (Danio rerio)

Science.gov (United States)

Mukhi, S.; Pan, X.; Cobb, G.P.; Patino, R.

2005-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine, a cyclonitramine commonly known as RDX, is used in the production of military munitions. Contamination of soil, sediment, and ground and surface waters with RDX has been reported in different places around the world. Acute and subacute toxicities of RDX have been relatively well documented in terrestrial vertebrates, but among aquatic vertebrates the information available is limited. The objective of this study was to characterize the acute toxicity of RDX to larval zebrafish. Mortality (LC50) and incidence of vertebral column deformities (EC50) were two of the end points measured in this study. The 96-h LC50 was estimated at 22.98 and 25.64 mg l-1 in two different tests. The estimated no-observed-effective- concentration (NOEC) values of RDX on lethality were 13.27 ?? 0.05 and 15.32 ?? 0.30 mg l-1; and the lowest-observed-effective- concentration (LOEC) values were 16.52 ?? 0.05 and 19.09 ?? 0.23 mg l-1 in these two tests, respectively. The 96-h EC50 for vertebral deformities on survivors from one of the acute lethality tests was estimated at 20.84 mg l-1, with NOEC and LOEC of 9.75 ?? 0.34 and 12.84 ?? 0.34 mg l-1, respectively. Behavioral aberrations were also noted in this acute toxicity study, including the occurrence of whirling movement and lethargic behavior. The acute effects of RDX on survival, incidence of deformities, and behavior of larval zebrafish occurred at the high end of the most frequently reported concentrations of RDX in aquatic environments. The chronic effects of RDX in aquatic vertebrates need to be determined for an adequate assessment of the ecological risk of environmental RDX. ?? 2005 Elsevier Ltd. All rights reserved.

Characterization of polymorphic states in energetic samples of 1,3,5-trinitro-1,3,5-triazine (RDX) fabricated using drop-on-demand inkjet technology.

Science.gov (United States)

Emmons, Erik D; Farrell, Mikella E; Holthoff, Ellen L; Tripathi, Ashish; Green, Norman; Moon, Raphael P; Guicheteau, Jason A; Christesen, Steven D; Pellegrino, Paul M; Fountain, Augustus W

2012-06-01

The United States Army and the first responder community are evaluating optical detection systems for the trace detection of hazardous energetic materials. Fielded detection systems must be evaluated with the appropriate material concentrations to accurately identify the residue in theater. Trace levels of energetic materials have been observed in mutable polymorphic phases and, therefore, the systems being evaluated must be able to detect and accurately identify variant sample phases observed in spectral data. In this work, we report on the novel application of drop-on-demand technology for the fabrication of standardized trace 1,3,5-trinitro-1,3,5-triazine (RDX) samples. The drop-on-demand sample fabrication technique is compared both visually and spectrally to the more commonly used drop-and-dry technique. As the drop-on-demand technique allows for the fabrication of trace level hazard materials, concerted efforts focused on characterization of the polymorphic phase changes observed with low concentrations of RDX commonly used in drop-on-demand processing. This information is important when evaluating optical detection technologies using samples prepared with a drop-on-demand inkjet system, as the technology may be "trained" to detect the common bulk α phase of the explosive based on its spectral features but fall short in positively detecting a trace quantity of RDX (β-phase). We report the polymorphic shifts observed between α- and β-phases of this energetic material and discuss the conditions leading to the favoring of one phase over the other.

Tracking the Fate of Explosive-Trinitrotriazine (RDX) in Coastal Marine Ecosystems Using Stable Isotopic Tracer

Science.gov (United States)

Ariyarathna, T. S.; Ballentine, M.; Vlahos, P.; Smith, R. W.; Bohlke, J. K.; Tobias, C. R.; Fallis, S.; Groshens, T.; Cooper, C.

2017-12-01

It has been estimated that there are hundreds of explosive-contaminated sites all over the world and managing these contaminated sites is an international challenge. As coastal zones and estuaries are commonly impacted zones, it is vital to understand the fate and transport of munition compounds in these environments. The demand for data on sorption, biodegradation and mineralization of trinitrotriazine (RDX) in coastal ecosystems is the impetus for this study using stable nitrogen isotopes to track its metabolic pathways. Mesocosm experiments representing subtidal vegetated, subtidal unvegetated and intertidal marsh ecocosms were conducted. Steady state concentrations of RDX were maintained in the systems throughout two-week time duration of experiments. Sediment, pore-water and overlying water samples were analyzed for RDX and degradation products. Isotope analysis of the bulk sediments revealed an initial rising inventory of 15N followed by a decay illustrating the role of sediments on sorption and degradation of RDX in anaerobic sediments respectively. Both pore-water and overlying water samples were analyzed for 15N inventories of different inorganic nitrogen pools including ammonium, nitrate, nitrite, nitrous oxide and nitrogen gases. RDX is mineralized to nitrogen gas through a series of intermediates leaving nitrous oxide as the prominent metabolite of RDX. Significant differences in RDX metabolism were observed in the three different ecosystems based on sediment characteristics and redox conditions in the systems. Fine grained organic carbon rich sediments show notably higher mineralization rates of RDX in terms of production of its metabolites. Quantification of degradation and transformation rates leads to mass balances of RDX in the systems. Further analysis of results provides insights for mineralization pathways of RDX into both organic and inorganic nitrogen pools entering the marine nitrogen cycle.

Capability of selected crop plants for shoot mercury accumulation from polluted soils: phytoremediation perspectives.

Science.gov (United States)

Rodriguez, Luis; Rincón, Jesusa; Asencio, Isaac; Rodríguez-Castellanos, Laura

2007-01-01

High-biomass crops can be considered as an alternative to hyperaccumulator plants to phytoremediate soils contaminated by heavy metals. In order to assess their practical capability for the absorption and accumulation of Hg in shoots, barley, white lupine, lentil, and chickpea were tested in pot experiments using several growth substrates. In the first experimental series, plants were grown in a mixture of vermiculite and perlite spiked with 8.35 microg g(-1) d.w. of soluble Hg. The mercury concentration of the plants' aerial tissues ranged from 1.51 to 5.13 microg g(-1) d.w. with lentil and lupine showing the highest values. In a second experiment carried out using a Hg-polluted soil (32.16 microg g(-1) d.w.) collected from a historical mining area (Almadén, Spain), the crop plants tested only reached shoot Hg concentration up to 1.13 microg g(-1) d.w. In the third experimental series, the Almadén soil was spiked with 1 microg g(-1) d.w. of soluble Hg; as a result, mercury concentrations in the plant shoots increased approximately 6 times for lupine, 5 times for chickpea, and 3.5 times for barley and lentil, with respect to those obtained with the original soil without Hg added. This marked difference was attributed to the low availability of Hg in the original Almadin soil and its subsequent increase in the Hg-spiked soil. The low mercury accumulation yields obtained for all plants do not make a successful decontamination of the Almadén soils possible byphytoremediation using crop plants. However, since the crops tested can effectively decrease the plant-available Hg level in this soil, their use could, to some extent, reduce the environmental risk of Hg pollution in the area.

PCDD/Fs atmospheric deposition fluxes and soil contamination close to a municipal solid waste incinerator.

Science.gov (United States)

Vassura, Ivano; Passarini, Fabrizio; Ferroni, Laura; Bernardi, Elena; Morselli, Luciano

2011-05-01

Bulk depositions and surface soil were collected in a suburban area, near the Adriatic Sea, in order to assess the contribution of a municipal solid waste incinerator to the area's total contamination with polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs and PCDFs). Samples were collected at two sites, situated in the area most affected by plant emissions (according to the results of the Calpuff air dispersion model), and at an external site, considered as a reference. Results show that the studied area is subject to low contamination, as far as these compounds are concerned. Deposition fluxes range from 14.3 pg m(-2)d(-1) to 89.9 pg m(-2)d(-1) (0.75 pg-TEQ m(-2)d(-1) to 3.73 pg-TEQ m(-2)d(-1)) and no significant flow differences are observed among the three monitored sites. Total soil concentration amounts to 93.8 ng kg(-1) d.w. and 1.35 ng-TEQ kg(-1)d.w, on average, and confirms a strong homogeneity in the studied area. Furthermore, from 2006 to 2009, no PCDD/Fs enrichment in the soil was noticed. Comparing the relative congener distributions in environmental samples with those found in stack emissions from the incineration plant, significant differences are observed in the PCDD:PCDF ratio and in the contribution of the most chlorinated congeners. From this study we can conclude that the incineration plant is not the main source of PCDD/Fs in the studied area, which is apparently characterized by a homogeneous and widespread contamination situation, typical of an urban area. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spatial distribution of chlordanes and PCB congeners in soil in Cedar Rapids, Iowa, USA

International Nuclear Information System (INIS)

Martinez, Andres; Erdman, Nicholas R.; Rodenburg, Zachary L.; Eastling, Paul M.; Hornbuckle, Keri C.

2012-01-01

Residential soils from Cedar Rapids, Iowa, USA were collected and analyzed for chlordanes and polychlorinated biphenyls (PCBs). This study is one of the very few urban soil investigations in the USA. The chlordanes concentrations ranged from 0 to 7500 ng g −1 dry weight (d.w.), with a mean and standard deviation of 130 ± 920 ng g −1 d.w., which is about 1000 times larger than background levels. ΣPCB concentrations ranged from 3 to 1200 ng g −1 d.w., with a mean and standard deviation of 56 ± 160 ng g −1 d.w. and are about 10 times higher than world-wide background levels. Both groups exhibit considerable variability in chemical patterns and site-to-site concentrations. Although no measurements of dioxins were carried out, the potential toxicity due to the 12 dioxin-like PCBs found in the soil is in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation. - Graphical Abstract: Spatial location and measured concentrations of ΣPCB (left, 64 sites) and chlordanes (right, 66 sites) (ng g −1 d.w.) in soil from Cedar Rapids, Iowa. Samples were collected in August 2008. Estimated flood area was obtained from the Linn County Auditor's Office. Highlights: ► Chlordanes and PCBs congeners were measured in surficial soil from Cedar Rapids, Iowa. ► Measured values for both chemical groups are similar to other urban/industrial site around the world. ► This is one of the few urban soil studies in the USA. ► TEQs values are in the same order of magnitude of the provisional threshold recommended by USEPA to perform soil remediation. - Chlordane compounds (trans-, cis- and trans-nonachlor) and PCBs (164 peaks for 209 congeners) were measured in the soils of a small medium-sized American city.

Total mercury, methyl mercury, and carbon in fresh and burned plants and soil in Northwestern Ontario

Energy Technology Data Exchange (ETDEWEB)

Mailman, M. [Department of Zoology, University of Manitoba, Winnipeg, Man. R3T 2N2 (Canada); Freshwater Institute, 501 University Crescent, Winnipeg, Man. R3T 2N6 (Canada)]. E-mail: mailmanma@dfo-mpo.gc.ca; Bodaly, R.A. [Department of Zoology, University of Manitoba, Winnipeg, Man. R3T 2N2 (Canada); Freshwater Institute, 501 University Crescent, Winnipeg, Man. R3T 2N6 (Canada)

2005-11-15

Terrestrial plants and soil contain substantial amounts of organic carbon (C) and mercury. Flooding terrestrial areas stimulates microbial methyl mercury (MeHg) production and fish obtain elevated MeHg concentrations. Our purpose was to determine the loss of C, total mercury (THg), and MeHg from boreal plants and soil after burning to assess the potential of burning before flooding to lower MeHg. Fresh plants contained 4 to 52 ng g{sup -1} dry weight (dw) of THg and 0.1 to 1.3 ng g{sup -1} dw of MeHg. Upland soils contained 162{+-}132 ng g{sup -1} dw of THg and 0.6{+-}0.6 ng g{sup -1} dw of MeHg. Complete burning caused plants to lose 96, 98, 97, and 94% of the mass, C, THg, and MeHg, respectively. Upland soil lost 27, 95, 79, and 82% of the mass, C, THg, and MeHg, respectively. Our results demonstrated that a substantial loss of C, THg, and MeHg was caused by burning. - Burning terrestrial vegetation and soil causes substantial losses of organic carbon, total mercury, and methyl mercury.

Total mercury, methyl mercury, and carbon in fresh and burned plants and soil in Northwestern Ontario

International Nuclear Information System (INIS)

Mailman, M.; Bodaly, R.A.

2005-01-01

Terrestrial plants and soil contain substantial amounts of organic carbon (C) and mercury. Flooding terrestrial areas stimulates microbial methyl mercury (MeHg) production and fish obtain elevated MeHg concentrations. Our purpose was to determine the loss of C, total mercury (THg), and MeHg from boreal plants and soil after burning to assess the potential of burning before flooding to lower MeHg. Fresh plants contained 4 to 52 ng g -1 dry weight (dw) of THg and 0.1 to 1.3 ng g -1 dw of MeHg. Upland soils contained 162±132 ng g -1 dw of THg and 0.6±0.6 ng g -1 dw of MeHg. Complete burning caused plants to lose 96, 98, 97, and 94% of the mass, C, THg, and MeHg, respectively. Upland soil lost 27, 95, 79, and 82% of the mass, C, THg, and MeHg, respectively. Our results demonstrated that a substantial loss of C, THg, and MeHg was caused by burning. - Burning terrestrial vegetation and soil causes substantial losses of organic carbon, total mercury, and methyl mercury

(134)Cs and ¹³⁷Cs levels in a grassland, 32 km northwest of the Fukushima 1 Nuclear Power Plant, measured for two seasons after the fallout.

Science.gov (United States)

Terashima, Ichiro; Shiyomi, Masae; Fukuda, Hiroo

2014-01-01

We measured the levels of radioactive caesium (RACs; ¹³⁴Cs and ¹³⁷Cs) in plants and soil in a grassland, 32 km northwest of the Fukushima 1 Nuclear Power Plant, from June 2011 to October 2012. In 2011, the highest RACs levels (¹³⁴Cs + ¹³⁷Cs) in plants and in the 0-5 cm soil layer were approximately 80 kBq per kg dry weight (DW). Forage grasses and clovers in this grassland showed similar RACs levels. On a DW basis, the levels of RACs in these plants tended to increase with increasing biomass over both years, but the absolute levels decreased in 2012. The RACs levels in the soil decreased sharply with soil depth; the RACs level in the 5-10 cm soil layer was only 3 % of that in the 0-5 cm layer. The transfer factor (ratio of radioactivity in plant parts on DW basis to that in the 0-10 cm soil layer) was 0.5 and 1.0 for the aboveground and belowground plant parts, respectively, in 2011, and these values decreased by approximately 50 % in 2012. We discuss the possible mechanisms underlying these trends, and strategies to decrease the level of RACs in plants to the permissible level for forage.

Shock-induced fast reactions of zinc nanoparticles and RDX

International Nuclear Information System (INIS)

Xue Mian; Wu Jinghe; Ye Song; Yang Xiangdong; Hu Dong; Wang Yanping; Zhu Wenjun; Li Chengbing

2008-01-01

Fast reactions of zinc nanoparticles and RDX were investigated in normal incident shock waves. The emergence time and emission spectra intensity of partial products such as NO 2 , H, C 2 , O, CO, CH 2 O, CO 2 , H 2 O and ZnO were observed by a TDS5054 oscilloscope. The results indicate that NO 2 appears first in each experiment, which is in agreement with the theoretical results. The addition of zinc nanoparticles to RDX can not only shorten the ignition delay time by 20% but also double the shockwave diffusion velocity to 2180 ± 50 m s -1 and triple the temperature to 2020 ± 60 K. The emergence time of products shortens by around 10-40% and the emission spectra intensity of H 2 O and CH 2 O rises by about three times and one times, respectively. CO 2 , H 2 O and O 2 in various concentrations were introduced into the zinc-RDX reaction, respectively, which indicate that O 2 made the ignition delay time shorten by over 30%, the effect of H 2 O was not prominent while CO 2 made the ignition delay time lag by around 30%. The results indicate that the Zn-O 2 reaction mainly occurs in O 2 , CO 2 and H 2 O

Effect of potassium application on root uptake of radiocesium in rice

International Nuclear Information System (INIS)

Saito, Takashi; Ohkoshi, Satoru; Fujimura, Shigeto

2013-01-01

After the Fukushima Daiichi Nuclear Power Plant accident that occurred in March 2011, the concentration of radiocesium in brown rice that has been produced in some area has exceeded the provisional regulation value. In order to decrease the concentration of radiocesium in brown rice, we investigated the effect of the application of potassium fertilizer in rice paddy fields on the root uptake of radiocesium. The observed concentration ratio of "1"3"4Cs to "1"3"7Cs was 0.81 at the time of sample collection, and the mean concentrations of radiocesium in the soils at depths of 0-5, 5-10, and 10-15 cm were 5879 Bq kg"-"1 DW, 3223 Bq kg"-"1 DW and 1835 Bq kg"-"1 DW, respectively. The results showed that the vertical distribution of radiocesium was not uniform, although the rice paddy fields had been plowed. The concentration of radiocesium at a depth of 0-5 cm in soil collected from the 5 different rice paddy fields was in the range of 2465-7823Bq kg"-"1 DW, showing an approximately 3-fold variation between the upper and lower limits of the range. The concentration of radiocesium in brown rice cultivated in 5 different fields, was in the range of 52-485 Bq kg"-"1. The concentration of radiocesium in brown rice was found to be not correlated with that in the soil, and the soil-to-brown rice transfer factor was found to lie in the range of 0.0075-0.11. However, the radiocesium in brown rice decreased with an increase in exchangeable potassium in the soil. The concentration of radiocesium in brown rice also decreased from 370 to 138 Bq kg"-"1 upon the application of a top dressing of potassium fertilizer. Thus, the application of potassium fertilizer is shown to reduce the concentration of radiocesium in brown rice. (author)

Integrated Data Collection Analysis (IDCA) Program — RDX Standard Data Sets

Energy Technology Data Exchange (ETDEWEB)

Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorensen, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Phillips, Jason J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shelley, Timothy J. [Bureau of Alcohol, Tobacco and Firearms, Huntsville, AL (United States); Reyes, Jose A. [Applied Research Associates, Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2013-03-04

The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of the RDX Type II Class 5 standard, for a third and fourth time in the Proficiency Test and averaged with the analysis results from the first and second time. The results, from averaging all four sets (1, 2, 3 and 4) of data suggest a material to have slightly more impact sensitivity, more BAM friction sensitivity, less ABL friction sensitivity, similar ESD sensitivity, and same DSC sensitivity, compared to the results from Set 1, which was used previously as the values for the RDX standard in IDCA Analysis Reports.

Measurements of 137Cs in the food-chain of lamb in the Faroe Islands in t period 1990-1999

International Nuclear Information System (INIS)

Joensen, H.P.

2002-01-01

Radiocaesium has been measured in the food-chain of lamb in nine uncultivated pastures in the Faroe Islands since 1990. The sampling programme includes soil from the uppermost 10 cm, mixed grass and lamb meat. Lamb faeces have been included since 1995. The results for the period 1990-99 show the following averages across the nine pastures: the 137 Cs deposition decreased from 5.8 kBq/m 2 in 1990 to 5.1 kBq/m 2 in 1999; the 137 CS concentration in mixed grass decreased from 155 Bq/kg(dw) in 1990 to 51 Bq/kg(dw) in 1999; the 137 CS concentration in lamb meat decreased from 26.0 Bq/kg(ww) in 1990 to 10.4 Bq/kg(ww) in 1999. Large variations are, however, observed between as well as within the pastures. Averaged across the pastures, the soil-to-grass transfer factor decreased from 30 . 10 -3 in m 2 /kg(dw) in 1990 to 13 . 10 -3 m 2 /kg(dw) in 1999, and the aggregated soil-to-lamb (meat) transfer factor decreased from 5.5 . 10 -3 m 2 /kg(ww) in 1990 to 2.0 . 10 -3 m 2 /kg(ww) in 1999. The effective ecological half-life of 137 CS in mixed grass and in lamb meat is estimated to be in the range 2.8-4.3 and 6.6-8.0 years, respectively. (au)

Copper pollution decreases the resistance of soil microbial community to subsequent dry-rewetting disturbance.

Science.gov (United States)

Li, Jing; Wang, Jun-Tao; Hu, Hang-Wei; Ma, Yi-Bing; Zhang, Li-Mei; He, Ji-Zheng

2016-01-01

Dry-rewetting (DW) disturbance frequently occurs in soils due to rainfall and irrigation, and the frequency of DW cycles might exert significant influences on soil microbial communities and their mediated functions. However, how microorganisms respond to DW alternations in soils with a history of heavy metal pollution remains largely unknown. Here, soil laboratory microcosms were constructed to explore the impacts of ten DW cycles on the soil microbial communities in two contrasting soils (fluvo-aquic soil and red soil) under three copper concentrations (zero, medium and high). Results showed that the fluctuations of substrate induced respiration (SIR) decreased with repeated cycles of DW alternation. Furthermore, the resistance values of substrate induced respiration (RS-SIR) were highest in non-copper-stressed (zero) soils. Structural equation model (SEM) analysis ascertained that the shifts of bacterial communities determined the changes of RS-SIR in both soils. The rate of bacterial community variance was significantly lower in non-copper-stressed soil compared to the other two copper-stressed (medium and high) soils, which might lead to the higher RS-SIR in the fluvo-aquic soil. As for the red soil, the substantial increase of the dominant group WPS-2 after DW disturbance might result in the low RS-SIR in the high copper-stressed soil. Moreover, in both soils, the bacterial diversity was highest in non-copper-stressed soils. Our results revealed that initial copper stress could decrease the resistance of soil microbial community structure and function to subsequent DW disturbance. Copyright © 2015. Published by Elsevier B.V.

Trace element mobility and transfer to vegetation within the Ethiopian Rift Valley lake areas.

Science.gov (United States)

Kassaye, Yetneberk A; Skipperud, Lindis; Meland, Sondre; Dadebo, Elias; Einset, John; Salbu, Brit

2012-10-26

To evaluate critical trace element loads in native vegetation and calculate soil-to-plant transfer factors (TFs), 11 trace elements (Cr, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb and Mn) have been determined in leaves of 9 taxonomically verified naturally growing terrestrial plant species as well as in soil samples collected around 3 Ethiopian Rift Valley lakes (Koka, Ziway and Awassa). The Cr concentration in leaves of all the plant species was higher than the "normal" range, with the highest level (8.4 mg per kg dw) being observed in Acacia tortilis from the Lake Koka area. Caper species (Capparis fascicularis) and Ethiopian dogstooth grass (Cynodon aethiopicus) from Koka also contained exceptionally high levels of Cd (1 mg per kg dw) and Mo (32.8 mg per kg dw), respectively. Pb, As and Cu concentrations were low in the plant leaves from all sites. The low Cu level in important fodder plant species (Cynodon aethiopicus, Acacia tortilis and Opuntia ficus-indicus) implies potential deficiency in grazing and browsing animals. Compared to the Canadian environmental quality guideline and maximum allowable concentration in agricultural soils, the total soil trace element concentrations at the studied sites are safe for agricultural crop production. Enrichment factor was high for Zn in soils around Lakes Ziway and Awassa, resulting in moderate to high transfer of Zn to the studied plants. A six step sequential extraction procedure on the soils revealed a relatively high mobility of Cd, Se and Mn. Strong association of most trace elements with the redox sensitive fraction and mineral lattice was also confirmed by partial redundancy analysis. TF (mg per kg dw plants/mg per kg dw soil) values based on the total (TF(total)) and mobile fractions (TF(mobile)) of soil trace element concentrations varied widely among elements and plant species, with the averaged TF(total) and TF(mobile) values ranging from 0.01-2 and 1-60, respectively. Considering the mobile fraction in soils should

Theoretical studies on the thermodynamic properties and detonation properties of cyclotrimethylene trinitramine (RDX with aluminum and boron metals.

Directory of Open Access Journals (Sweden)

Nilgün Şen

2016-10-01

Full Text Available The B3LYP/6-311++G(2df,2p density functional theory (DFT method was used to investigate molecular geometry and thermodynamic properties of RDX and RDX derivatives containing Al and B metals. The detonation velocity (D and detonation pressure (P, estimated by using Kamlet–Jacobs and in literature equations, respectively. Total energies (Et, frontier orbital energy (EHOMO, ELOMO, energy gap (ΔELUMO–HOMO and theoretical molecular density (ρ were calculated with Spartan 14 software package program. It was shown that the presence of aluminum and boron atoms affects the good thermal stabilities. The results show that the composite RDX-Al, RDX-B derivatives have higher detonation performance and higher density than RDX. RDX-Al derivatives appeared to be superior to RDX-B mixtures in terms of these parameters. These results provide information on the moleculer design of new energetic materials.

Polarizability of acetanilide and RDX in the crystal: effect of molecular geometry

Science.gov (United States)

Tsiaousis, D.; Munn, R. W.; Smith, P. J.; Popelier, P. L. A.

2004-10-01

Density-functional theory with the B3LYP functional at the 6-311++G** level is used to calculate the dipole moment and the static polarizability for acetanilide and 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) in their in-crystal structures. For acetanilide the dipole moment is 2{1}/{2}% larger than for the gas-phase structure and for RDX (where there is a gross geometry change) it is 15% larger. The polarizability for the in-crystal structure is smaller than for the gas-phase structure by 3% for both species, whereas the in-crystal effective optical polarizability is larger than the gas-phase static polarizability for both crystals. Hence, effects in addition to the molecular geometry change in the crystal must be considered in order to interpret the effective polarizability completely.

Shock-induced fast reactions of zinc nanoparticles and RDX

Energy Technology Data Exchange (ETDEWEB)

Xue Mian; Wu Jinghe; Ye Song; Yang Xiangdong [Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 (China); Hu Dong; Wang Yanping; Zhu Wenjun; Li Chengbing [National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, CAEP, Mianyang 621900 (China)], E-mail: mi-anxue@163.com

2008-02-21

Fast reactions of zinc nanoparticles and RDX were investigated in normal incident shock waves. The emergence time and emission spectra intensity of partial products such as NO{sub 2}, H, C{sub 2}, O, CO, CH{sub 2}O, CO{sub 2}, H{sub 2}O and ZnO were observed by a TDS5054 oscilloscope. The results indicate that NO{sub 2} appears first in each experiment, which is in agreement with the theoretical results. The addition of zinc nanoparticles to RDX can not only shorten the ignition delay time by 20% but also double the shockwave diffusion velocity to 2180 {+-} 50 m s{sup -1} and triple the temperature to 2020 {+-} 60 K. The emergence time of products shortens by around 10-40% and the emission spectra intensity of H{sub 2}O and CH{sub 2}O rises by about three times and one times, respectively. CO{sub 2}, H{sub 2}O and O{sub 2} in various concentrations were introduced into the zinc-RDX reaction, respectively, which indicate that O{sub 2} made the ignition delay time shorten by over 30%, the effect of H{sub 2}O was not prominent while CO{sub 2} made the ignition delay time lag by around 30%. The results indicate that the Zn-O{sub 2} reaction mainly occurs in O{sub 2}, CO{sub 2} and H{sub 2}O.

Modelling DW-MRI data from primary and metastatic ovarian tumours

Energy Technology Data Exchange (ETDEWEB)

Winfield, Jessica M. [Institute of Cancer Research, CRUK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, Surrey (United Kingdom); Royal Marsden NHS Foundation Trust, Surrey (United Kingdom); Institute of Cancer Research and Royal Marsden Hospital, MRI Unit, Surrey (United Kingdom); DeSouza, Nandita M.; Collins, David J. [Institute of Cancer Research, CRUK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, Surrey (United Kingdom); Royal Marsden NHS Foundation Trust, Surrey (United Kingdom); Priest, Andrew N.; Hodgkin, Charlotte; Freeman, Susan [University of Cambridge, Department of Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Wakefield, Jennifer C.; Orton, Matthew R. [Institute of Cancer Research, CRUK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, Surrey (United Kingdom)

2015-07-15

To assess goodness-of-fit and repeatability of mono-exponential, stretched exponential and bi-exponential models of diffusion-weighted MRI (DW-MRI) data in primary and metastatic ovarian cancer. Thirty-nine primary and metastatic lesions from thirty-one patients with stage III or IV ovarian cancer were examined before and after chemotherapy using DW-MRI with ten diffusion-weightings. The data were fitted with (a) a mono-exponential model to give the apparent diffusion coefficient (ADC), (b) a stretched exponential model to give the distributed diffusion coefficient (DDC) and stretching parameter (α), and (c) a bi-exponential model to give the diffusion coefficient (D), perfusion fraction (f) and pseudodiffusion coefficient (D*). Coefficients of variation, established from repeated baseline measurements, were: ADC 3.1 %, DDC 4.3 %, α 7.0 %, D 13.2 %, f 44.0 %, D* 165.1 %. The bi-exponential model was unsuitable in these data owing to poor repeatability. After excluding the bi-exponential model, analysis using Akaike Information Criteria showed that the stretched exponential model provided the better fit to the majority of pixels in 64 % of lesions. The stretched exponential model provides the optimal fit to DW-MRI data from ovarian, omental and peritoneal lesions and lymph nodes in pre-treatment and post-treatment measurements with good repeatability. (orig.)

Residues of Avermectin B1a in rotational crops and soils following soil treatment with [14C]Avermectin B1a

International Nuclear Information System (INIS)

Moye, H.A.; Malagodi, M.H.; Yoh, H.; Leibee, G.L.; Ku, C.C.; Wislocki, P.G.

1987-01-01

[ 14 C]Avermectin B 1 a was applied twelve times to muck and sandy loam soils and three times to sandy soil at 0.025-0.030 lb/acre per application. These applications simulated the intended use of avermectin B 1 a on celery, vegetables, and cotton, respectively. Following three aging periods in each soil type, sorghum, lettuce, and carrot or turnip seeds were planted and harvested at one-fourth, half, and full size. Analysis of these crops by oxidative combustion demonstrated that crops grown in muck, sandy loam, and sandy soils contained radiolabeled residues ranging from below the limit of quantitation (BLQ) to 7.4 μg/kg of avermectin B 1 a equivalents, BLQ to 11.6 μg/kg, and BLQ to 3.54 μg/kg, respectively. There was a general trend of decreasing residue concentrations with increasing preharvest intervals in crops grown in all soils. The radioactivity present in muck and sandy loam soils disappeared with half-lives ranging from 103 to 267 days and from 102 to 132 days, respectively

Functional specification and architecture of EIAO DW, R2.2

DEFF Research Database (Denmark)

Pedersen, Torben Bach; Thomsen, Christian

In this document, the functional specification and architecture for the EIAO DW is presented. EIAO DW is a data warehouse that holds results from the European Internet Accessibility Observatory (EIAO) project. These results are mainly on the accessibility to disabled users of web resources...

Copper Pollution Increases the Resistance of Soil Archaeal Community to Changes in Water Regime.

Science.gov (United States)

Li, Jing; Liu, Yu-Rong; Cui, Li-Juan; Hu, Hang-Wei; Wang, Jun-Tao; He, Ji-Zheng

2017-11-01

Increasing efforts have been devoted to exploring the impact of environmental stresses on soil bacterial communities, but the work on the archaeal community is seldom. Here, we constructed microcosm experiments to investigate the responses of archaeal communities to the subsequent dry-rewetting (DW) disturbance in two contrasting soils (fluvo-aquic and red soil) after 6 years of copper pollution. Ten DW cycles were exerted on the two soils with different copper levels, followed by a 6-week recovery period. In both soils, archaeal diversity (Shannon index) in the high copper-level treatments increased over the incubation period, and archaeal community structure changed remarkably as revealed by the non-metric multidimensional scaling ordinations. In both soils, copper pollution altered the response of dominant operational taxonomic units (OTUs) to the DW disturbance. Throughout the incubation and recovery period, the resistance of archaeal abundance to the DW disturbance was higher in the copper-polluted soils than soils without pollution. Taken together, copper pollution altered the response of soil archaeal diversity and community composition to the DW disturbance and increased the resistance of the archaeal abundance. These findings have important implications for understanding soil microbial responses to ongoing environmental change.

The effects of the insecticide lambda-Cyhalothrin on the earthworm Eisenia fetida under experimental conditions of tropical and temperate regions

International Nuclear Information System (INIS)

Garcia, Marcos; Scheffczyk, Adam; Garcia, Terezinha; Roembke, Joerg

2011-01-01

Plant Protection Products can affect soil organisms and thus might have negative impacts on soil functions. Little research has been performed on their impact on tropical soils. Therefore, the effects of the insecticide lambda-Cyhalothrin on earthworms were evaluated in acute and chronic laboratory tests modified for tropical conditions, i.e. at selected temperatures (20 and 28 o C) and with two strains (temperate and tropical) of the compost worm Eisenia fetida. The insecticide was spiked in two natural soils, in OECD artificial soil and a newly developed tropical artificial soil. The effects of lambda-Cyhalothrin did rarely vary in the same soil at tropical (LC50: 68.5-229 mg a.i./kg dry weight (DW); EC50: 54.2-60.2 mg a.i./kg DW) and temperate (LC50: 99.8-140 mg a.i./kg DW; EC50: 37.4-44.5 mg a.i./kg DW) temperatures. In tests with tropical soils and high temperature, effect values differed by up to a factor of ten. - Research highlights: → In one soil, effects of lambda-Cyhalothrin did not vary much at two temperatures. → In tropical soils at high temperature, effects differed by up to a factor of ten. → In the tropics, effects of pesticides can be higher or lower as in temperate regions. - The effects of the insecticide lambda-cyhalothrin on earthworms did not differ considerably when performed in the same soil under different temperatures, but LC/EC 50 values varied by a factor of ten between OECD and tropical artificial soil.

The effects of the insecticide lambda-Cyhalothrin on the earthworm Eisenia fetida under experimental conditions of tropical and temperate regions

Energy Technology Data Exchange (ETDEWEB)

Garcia, Marcos [Embrapa Amazonia Ocidental, Rod. AM-10, Km 28, 69.011-970 Manaus, AM (Brazil); Scheffczyk, Adam [ECT Oekotoxikologie, Boettgerstr. 2-14, D-65439 Floersheim (Germany); Garcia, Terezinha [Embrapa Amazonia Ocidental, Rod. AM-10, Km 28, 69.011-970 Manaus, AM (Brazil); Roembke, Joerg, E-mail: j-roembke@ect.d [ECT Oekotoxikologie, Boettgerstr. 2-14, D-65439 Floersheim (Germany)

2011-02-15

Plant Protection Products can affect soil organisms and thus might have negative impacts on soil functions. Little research has been performed on their impact on tropical soils. Therefore, the effects of the insecticide lambda-Cyhalothrin on earthworms were evaluated in acute and chronic laboratory tests modified for tropical conditions, i.e. at selected temperatures (20 and 28 {sup o}C) and with two strains (temperate and tropical) of the compost worm Eisenia fetida. The insecticide was spiked in two natural soils, in OECD artificial soil and a newly developed tropical artificial soil. The effects of lambda-Cyhalothrin did rarely vary in the same soil at tropical (LC50: 68.5-229 mg a.i./kg dry weight (DW); EC50: 54.2-60.2 mg a.i./kg DW) and temperate (LC50: 99.8-140 mg a.i./kg DW; EC50: 37.4-44.5 mg a.i./kg DW) temperatures. In tests with tropical soils and high temperature, effect values differed by up to a factor of ten. - Research highlights: In one soil, effects of lambda-Cyhalothrin did not vary much at two temperatures. In tropical soils at high temperature, effects differed by up to a factor of ten. In the tropics, effects of pesticides can be higher or lower as in temperate regions. - The effects of the insecticide lambda-cyhalothrin on earthworms did not differ considerably when performed in the same soil under different temperatures, but LC/EC{sub 50} values varied by a factor of ten between OECD and tropical artificial soil.

Reversal of rocuronium-induced (1.2 mg kg-1) profound neuromuscular block by accidental high dose of sugammadex (40 mg kg-1).

NARCIS (Netherlands)

Molina, A.L.; Boer, H.D. de; Klimek, M.; Heeringa, M.; Klein, J.

2007-01-01

Sugammadex is the first selective relaxant binding agent and reverses rocuronium-induced neuromuscular block. A case is reported in which a patient accidentally received a high dose of sugammadex (40 mg kg-1) to reverse a rocuronium-induced (1.2 mg kg-1) profound neuromuscular block. A fast and

Aminoxyl (nitroxyl) radicals in the early decomposition of the nitramine RDX.

Science.gov (United States)

Irikura, Karl K

2013-03-14

The explosive nitramine RDX (1,3,5-trinitrohexahydro-s-triazine) is thought to decompose largely by homolytic N-N bond cleavage, among other possible initiation reactions. Density-functional theory (DFT) calculations indicate that the resulting secondary aminyl (R2N·) radical can abstract an oxygen atom from NO2 or from a neighboring nitramine molecule, producing an aminoxyl (R2NO·) radical. Persistent aminoxyl radicals have been detected in electron-spin resonance (ESR) experiments and are consistent with autocatalytic "red oils" reported in the experimental literature. When the O-atom donor is a nitramine, a nitrosamine is formed along with the aminoxyl radical. Reactions of aminoxyl radicals can lead readily to the "oxy-s-triazine" product (as the s-triazine N-oxide) observed mass-spectrometrically by Behrens and co-workers. In addition to forming aminoxyl radicals, the initial aminyl radical can catalyze loss of HONO from RDX.

SoilGrids1km — Global Soil Information Based on Automated Mapping

Science.gov (United States)

Hengl, Tomislav; de Jesus, Jorge Mendes; MacMillan, Robert A.; Batjes, Niels H.; Heuvelink, Gerard B. M.; Ribeiro, Eloi; Samuel-Rosa, Alessandro; Kempen, Bas; Leenaars, Johan G. B.; Walsh, Markus G.; Gonzalez, Maria Ruiperez

2014-01-01

Background Soils are widely recognized as a non-renewable natural resource and as biophysical carbon sinks. As such, there is a growing requirement for global soil information. Although several global soil information systems already exist, these tend to suffer from inconsistencies and limited spatial detail. Methodology/Principal Findings We present SoilGrids1km — a global 3D soil information system at 1 km resolution — containing spatial predictions for a selection of soil properties (at six standard depths): soil organic carbon (g kg−1), soil pH, sand, silt and clay fractions (%), bulk density (kg m−3), cation-exchange capacity (cmol+/kg), coarse fragments (%), soil organic carbon stock (t ha−1), depth to bedrock (cm), World Reference Base soil groups, and USDA Soil Taxonomy suborders. Our predictions are based on global spatial prediction models which we fitted, per soil variable, using a compilation of major international soil profile databases (ca. 110,000 soil profiles), and a selection of ca. 75 global environmental covariates representing soil forming factors. Results of regression modeling indicate that the most useful covariates for modeling soils at the global scale are climatic and biomass indices (based on MODIS images), lithology, and taxonomic mapping units derived from conventional soil survey (Harmonized World Soil Database). Prediction accuracies assessed using 5–fold cross-validation were between 23–51%. Conclusions/Significance SoilGrids1km provide an initial set of examples of soil spatial data for input into global models at a resolution and consistency not previously available. Some of the main limitations of the current version of SoilGrids1km are: (1) weak relationships between soil properties/classes and explanatory variables due to scale mismatches, (2) difficulty to obtain covariates that capture soil forming factors, (3) low sampling density and spatial clustering of soil profile locations. However, as the Soil

Utilization of steel, pulp and paper industry solid residues in forest soil amendment: relevant physicochemical properties and heavy metal availability.

Science.gov (United States)

Mäkelä, Mikko; Watkins, Gary; Pöykiö, Risto; Nurmesniemi, Hannu; Dahl, Olli

2012-03-15

Industrial residue application to soil was investigated by integrating granulated blast furnace or converter steel slag with residues from the pulp and paper industry in various formulations. Specimen analysis included relevant physicochemical properties, total element concentrations (HCl+HNO3 digestion, USEPA 3051) and chemical speciation of chosen heavy metals (CH3COOH, NH2OH·HCl and H2O2+H2O2+CH3COONH4, the BCR method). Produced matrices showed liming effects comparable to commercial ground limestone and included significant quantities of soluble vital nutrients. The use of converter steel slag, however, led to significant increases in the total concentrations of Cr and V. Subsequently, total Cr was attested to occur as Cr(III) by Na2CO3+NaOH digestion followed by IC UV/VIS-PCR (USEPA 3060A). Additionally, 80.6% of the total concentration of Cr (370 mg kg(-1), d.w.) occurred in the residual fraction. However, 46.0% of the total concentration of V (2470 mg kg(-1), d.w.) occurred in the easily reduced fraction indicating potential bioavailability. Copyright © 2011 Elsevier B.V. All rights reserved.

Antipneumococcal activity of DW-224a, a new quinolone, compared to those of eight other agents.

Science.gov (United States)

Kosowska-Shick, Klaudia; Credito, Kim; Pankuch, Glenn A; Lin, Gengrong; Bozdogan, Bülent; McGhee, Pamela; Dewasse, Bonifacio; Choi, Dong-Rack; Ryu, Jei Man; Appelbaum, Peter C

2006-06-01

DW-224a is a new broad-spectrum quinolone with excellent antipneumococcal activity. Agar dilution MIC was used to test the activity of DW-224a compared to those of penicillin, ciprofloxacin, levofloxacin, gatifloxacin, moxifloxacin, gemifloxacin, amoxicillin-clavulanate, cefuroxime, and azithromycin against 353 quinolone-susceptible pneumococci. The MICs of 29 quinolone-resistant pneumococci with defined quinolone resistance mechanisms against seven quinolones and an efflux mechanism were also tested. DW-224a was the most potent quinolone against quinolone-susceptible pneumococci (MIC(50), 0.016 microg/ml; MIC(90), 0.03 microg/ml), followed by gemifloxacin, moxifloxacin, gatifloxacin, levofloxacin, and ciprofloxacin. beta-Lactam MICs rose with those of penicillin G, and azithromycin resistance was seen mainly in strains with raised penicillin G MICs. Against the 29 quinolone-resistant strains, DW-224a had the lowest MICs (0.06 to 1 microg/ml) compared to those of gemifloxacin, clinafloxacin, moxifloxacin, gatifloxacin, levofloxacin, and ciprofloxacin. DW-224a at 2x MIC was bactericidal after 24 h against eight of nine strains tested. Other quinolones gave similar kill kinetics relative to higher MICs. Serial passages of nine strains in the presence of sub-MIC concentrations of DW-224a, moxifloxacin, levofloxacin, ciprofloxacin, gatifloxacin, gemifloxacin, amoxicillin-clavulanate, cefuroxime, and azithromycin were performed. DW-224a yielded resistant clones similar to moxifloxacin and gemifloxacin but also yielded lower MICs. Azithromycin selected resistant clones in three of the five parents tested. Amoxicillin-clavulanate and cefuroxime did not yield resistant clones after 50 days.

Contributions of available substrates and activities of trophic microbial community to methanogenesis in vegetative and reproductive rice rhizospheric soil.

Science.gov (United States)

Chawanakul, Sansanee; Chaiprasert, Pawinee; Towprayoon, Sirintornthep; Tanticharoen, Morakot

2009-01-01

Potential of methane production and trophic microbial activities at rhizospheric soil during rice cv. Supanbunri 1 cultivation were determined by laboratory anaerobic diluents vials. The methane production was higher from rhizospheric than non-rhizospheric soil, with the noticeable peaks during reproductive phase (RP) than vegetative phase (VP). Glucose, ethanol and acetate were the dominant available substrates found in rhizospheric soil during methane production at both phases. The predominance activities of trophic microbial consortium in methanogenesis, namely fermentative bacteria (FB), acetogenic bacteria (AGB), acetate utilizing bacteria (AB) and acetoclastic methanogens (AM) were also determined. At RP, these microbial groups were enhanced in the higher of methane production than VP. This correlates with our finding that methane production was greater at the rhizospheric soil with the noticeable peaks during RP (1,150 +/- 60 nmol g dw(-1) d(-1)) compared with VP (510 +/- 30 nmol g dw(-1) d(-1)). The high number of AM showed the abundant (1.1x10(4) cell g dw(-1)) with its high activity at RP, compared to the less activity with AM number at VP (9.8x10(2) cell g dw(-1)). Levels of AM are low in the total microbial population, being less than 1% of AB. These evidences revealed that the microbial consortium of these two phases were different.

PAH exposure through soil ingestion: Combining digestion models and bioassays

Energy Technology Data Exchange (ETDEWEB)

Wiele, T.R. van de; Verstraete, W. [Ghent University (BE).Laboratory Microbial Ecology and Technology (LabMET); Siciliano, S.D. [University of Saskatchewan (Canada). Department of Soil Science

2003-07-01

Exposure to environmental contaminants through soil ingestion is an important issue in current health risk assessment. Polycyclic aromatic hydrocarbons (PAH) or their metabolites pose risks to humans due to their toxic, mutagenic, carcinogenic or even (anti)estrogenic properties. PAH mobilization from a soil matrix (49.1{+-}1.5 mg PAH/kg DW) was assessed using a Simulator of the Human Intestinal Microbial Ecosystem (SHIME). PAH GC-MS analysis was performed on the pellet and supernatant of SHIME digests and gave 101, 92, 89 and 97% recovery for water, stomach, duodenal and colon digests, respectively. PAH release was highest for the water extract (0.51%) and the stomach digestion (0.44%). Lower mobilized fractions in the duodenum (0.13%) and colon (0.30%) digests could be attributed to PAH complexation with bile salts, dissolved organic matter or colon microbiota. The digestion model provides us with relevant information to what extent soil bound PAHs are mobilized in the gastrointestinal tract and thus reach the gut wall, prior to absorption. (orig.)

Measurement of technetium-99 in Marshall Islands soil samples by ICP-MS

International Nuclear Information System (INIS)

Tagami, K.; Uchida, S.; Hamilton, T.; Robison, W.

2000-01-01

Extraction techniques for recovery of technetium-99 ( 99 Tc) for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (M1) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc from raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for 99 Tc. Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the 99 Tc content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The 99 Tc activity concentration in the soil samples ranged between 0.1 and 1.1 mBq g -1 dry weight (dw). The limit of detection for 99 Tc by ICP-MS was 0.17 mBq per sample or 0.014 mBq g -1 dw under standard operating conditions

DW-MRI as a Predictive Biomarker of Radiosensitization of GBM through Targeted Inhibition of Checkpoint Kinases.

Science.gov (United States)

Williams, Terence M; Galbán, Stefanie; Li, Fei; Heist, Kevin A; Galbán, Craig J; Lawrence, Theodore S; Holland, Eric C; Thomae, Tami L; Chenevert, Thomas L; Rehemtulla, Alnawaz; Ross, Brian D

2013-04-01

The inherent treatment resistance of glioblastoma (GBM) can involve multiple mechanisms including checkpoint kinase (Chk1/2)-mediated increased DNA repair capability, which can attenuate the effects of genotoxic chemotherapies and radiation. The goal of this study was to evaluate diffusion-weighted magnetic resonance imaging (DW-MRI) as a biomarker for Chk1/2 inhibitors in combination with radiation for enhancement of treatment efficacy in GBM. We evaluated a specific small molecule inhibitor of Chk1/2, AZD7762, in combination with radiation using in vitro human cell lines and in vivo using a genetically engineered GBM mouse model. DW-MRI and T1-contrast MRI were used to follow treatment effects on intracranial tumor cellularity and growth rates, respectively. AZD7762 inhibited clonal proliferation in a panel of GBM cell lines and increased radiosensitivity in p53-mutated GBM cell lines to a greater extent compared to p53 wild-type cells. In vivo efficacy of AZD7762 demonstrated a dose-dependent inhibitory effect on GBM tumor growth rate and a reduction in tumor cellularity based on DW-MRI scans along with enhancement of radiation efficacy. DW-MRI was found to be a useful imaging biomarker for the detection of radiosensitization through inhibition of checkpoint kinases. Chk1/2 inhibition resulted in antiproliferative activity, prevention of DNA damage-induced repair, and radiosensitization in preclinical GBM tumor models, both in vitro and in vivo. The effects were found to be maximal in p53-mutated GBM cells. These results provide the rationale for integration of DW-MRI in clinical translation of Chk1/2 inhibition with radiation for the treatment of GBM.

Thermal Decomposition Behaviors and Burning Characteristics of AN/RDX-Based Composite Propellants Supplemented with MnO2 and Fe2O3

Science.gov (United States)

Kohga, Makoto; Naya, Tomoki

2015-10-01

Ammonium nitrate (AN)-based composite propellants have gained popularity because of the clean burning nature of AN as an oxidizer. However, such propellants have several disadvantages such as poor ignition and low burning rate. The burning characteristics of the AN propellant were improved when a portion of this propellant was replaced by an energetic material and the addition of a catalyst. In this study, RDX (1,3,5-trinitroperhydro-1,3,5-triazine) was used as the energetic material, and Fe2O3 and MnO2 were used as catalysts. The burning characteristics of the AN/RDX propellants supplemented with catalysts were investigated, and the effects of the replacement of AN by RDX and the catalyst addition were evaluated.

Measurement of technetium-99 in soil samples collected in Marshall Islands

Energy Technology Data Exchange (ETDEWEB)

Tagami, K.; Uchida, S. [National Inst. of Radiological Sciences, Environmental and Toxicological Sciences Research Group, Chiba (Japan)

2000-07-01

Extraction techniques for recovery of technetium-99 ({sup 99}Tc) for ICP-MS measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (M1) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc from raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for {sup 99}Tc. Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the {sup 99}Tc content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The {sup 99}Tc activity concentration in the soil samples ranged between 0.1 and 1.1 mBq/g-dw. The limit of detection for {sup 99}Tc by ICP-MS was 0.17 mBq per sample or 0.014 mBq/g-dw under standard operating conditions. (author)

Measurement of technetium-99 in soil samples collected in Marshall Islands

International Nuclear Information System (INIS)

Tagami, K.; Uchida, S.

2000-01-01

Extraction techniques for recovery of technetium-99 ( 99 Tc) for ICP-MS measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (M1) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc from raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for 99 Tc. Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the 99 Tc content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The 99 Tc activity concentration in the soil samples ranged between 0.1 and 1.1 mBq/g-dw. The limit of detection for 99 Tc by ICP-MS was 0.17 mBq per sample or 0.014 mBq/g-dw under standard operating conditions. (author)

Effect of soil organic matter content and pH on the toxicity of ZnO nanoparticles to Folsomia candida.

Science.gov (United States)

Waalewijn-Kool, Pauline L; Rupp, Svenja; Lofts, Stephen; Svendsen, Claus; van Gestel, Cornelis A M

2014-10-01

Organic matter (OM) and pH may influence nanoparticle fate and effects in soil. This study investigated the influence of soil organic matter content and pH on the toxicity of ZnO-NP and ZnCl2 to Folsomia candida in four natural soils, having between 2.37% and 14.7% OM and [Formula: see text] levels between 5.0 and 6.8. Porewater Zn concentrations were much lower in ZnO-NP than in ZnCl2 spiked soils, resulting in higher Freundlich sorption constants for ZnO-NP. For ZnCl2 the porewater Zn concentrations were significantly higher in less organic soils, while for ZnO-NP the highest soluble Zn level (23mgZn/l) was measured in the most organic soil, which had the lowest pH. Free Zn(2+) ion concentrations were higher for ZnCl2 than for ZnO-NP and were greatly dependent on pH (pHpw) and dissolved organic carbon content of the pore water. The 28-d EC50 values for the effect of ZnCl2 on the reproduction of F. candida increased with increasing OM content from 356 to 1592mgZn/kg d.w. For ZnO-NP no correlation between EC50 values and OM content was found and EC50 values ranged from 1695 in the most organic soil to 4446mgZn/kg d.w. in the higher pH soil. When based on porewater and free Zn(2+) concentrations, EC50 values were higher for ZnCl2 than for ZnO-NP, and consistently decreased with increasing pHpw. This study shows that ZnO-NP toxicity is dependent on soil properties, but is mainly driven by soil pH. Copyright © 2014 Elsevier Inc. All rights reserved.

Effects of hydrogen bonds on solid state TATB, RDX, and DATB under high pressures

International Nuclear Information System (INIS)

Guo Feng; Hu Hai-Quan; Zhang Hong; Cheng Xin-Lu

2014-01-01

To probe the behavior of hydrogen bonds in solid energetic materials, we conduct ReaxFF and SCC–DFTB molecular dynamics simulations of crystalline TATB, RDX, and DATB. By comparing the intra- and inter-molecular hydrogen bonding rates, we find that the crystal structures are stabilized by inter-molecular hydrogen bond networks. Under high-pressure, the inter- and intra-molecular hydrogen bonds in solid TATB and DATB are nearly equivalent. The hydrogen bonds in solid TATB and DATB are much shorter than in solid RDX, which suggests strong hydrogen bond interactions existing in these energetic materials. Stretching of the C–H bond is observed in solid RDX, which may lead to further decomposition and even detonation. (condensed matter: structural, mechanical, and thermal properties)

Measurement of technetium-99 in Marshall Islands soil samples by ICP-MS

Science.gov (United States)

Tagami; Uchida; Hamilton; Robison

2000-07-01

Extraction techniques for recovery of technetium-99 (99Tc) for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (MI) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc from raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for 99Tc. Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the 99Tc content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The 99Tc activity concentration in the soil samples ranged between 0.1 and 1.1 mBq g(-1) dry weight (dw). The limit of detection for 99Tc by ICP-MS was 0.17 mBq per sample or 0.014 mBq g(-1) dw under standard operating conditions.

Passive Biobarrier for Treating Co-mingled Perchlorate and RDX in Groundwater at an Active Range

Science.gov (United States)

2016-05-12

16S rRNA sequences were derived. These sequences resided in four major clusters: Actinobacteria (Eggerthella), -Proteobacteria (unclassified...Proteobacteria, Actinobacteria , -Proteobacteria and Clostridia) have been previously reported to biodegrade RDX directly, or to contribute to RDX...detected primarily under manganese-reducing conditions (with one under sulfate- reducing conditions) in our study, remain unclear. Actinobacteria are

Phthalate esters contamination in soils and vegetables of plastic film greenhouses of suburb Nanjing, China and the potential human health risk.

Science.gov (United States)

Ma, Ting Ting; Wu, Long Hua; Chen, Like; Zhang, Hai Bo; Teng, Ying; Luo, Yong Ming

2015-08-01

The contamination of phthalate esters (PAEs) has become a potential threat to the environment and human health because they could be easily released as plasticizers from the daily supply products, especially in polyethylene films. Concentration levels of total six PAEs, nominated as priority pollutants by the US Environmental Protection Agency (USEPA), were investigated in soils and vegetables from four greenhouse areas in suburbs of Nanjing, East China. Total PAEs concentration ranged from 930 ± 840 to 2,450 ± 710 μg kg(-1) (dry weight (DW)) in soil and from 790 ± 630 to 3,010 ± 2,130 μg kg(-1) in vegetables. Higher concentrations of PAEs were found in soils except in Suo Shi (SS) area and in vegetables, especially in potherb mustard and purple tsai-tai samples. Risk assessment mainly based on the exposures of soil ingestion and daily vegetable intake indicated that bis(2-ethylhexyl) phthalate (DEHP) in the samples from Gu Li (GL) and Hu Shu (HS) exhibited the highest hazard to children less than 6-year old. Therefore, the human health risk of the PAEs contamination in soils and vegetables should greatly be of a concern, especially for their environmental estrogen analog effects.

Computational Study of the Structure and Mechanical Properties of the Molecular Crystal RDX

Science.gov (United States)

2012-11-01

basic equilibrium properties of and transitions to and from the α and γ polymorphs in crystalline RDX based on the SB potential (17). Atomic-level...elastic constants, polymorph transitions , cleavage properties, and energy barriers to slip. The energy barriers to slip are determined through the... RDX molecule containing three R2N-NO2 groups, where each R=CH2; and (c) HMX molecule containing four R2N-NO2 groups with R=CH2

Treatment of RDX & HMX Plumes Using Mulch Biowalls

Science.gov (United States)

2008-08-01

BAK Benzalkonium chloride BGS Below Ground Surface BRAC Base Realignment and Closure CHAAP Cornhusker Army Ammunition Plant CDPHE Colorado...Metabolism, and Reductive Transformation of RDX .............................................................. 9  Figure 4. Plan View Schematic of...43  Figure 17. Oxidation- reduction Potential (ORP) Measurement Averaged Over Different Well- rows

Reactive simulation of the chemistry behind the condensed-phase ignition of RDX from hot spots.

Science.gov (United States)

Joshi, Kaushik L; Chaudhuri, Santanu

2015-07-28

Chemical events that lead to thermal initiation and spontaneous ignition of the high-pressure phase of RDX are presented using reactive molecular dynamics simulations. In order to initiate the chemistry behind thermal ignition, approximately 5% of RDX crystal is subjected to a constant temperature thermal pulse for various time durations to create a hot spot. After application of the thermal pulse, the ensuing chemical evolution of the system is monitored using reactive molecular dynamics under adiabatic conditions. Thermal pulses lasting longer than certain time durations lead to the spontaneous ignition of RDX after an incubation period. For cases where the ignition is observed, the incubation period is dominated by intermolecular and intramolecular hydrogen transfer reactions. Contrary to the widely accepted unimolecular models of initiation chemistry, N-N bond dissociations that produce NO2 species are suppressed in the condensed phase. The gradual temperature and pressure increase in the incubation period is accompanied by the accumulation of short-lived, heavier polyradicals. The polyradicals contain intact triazine rings from the RDX molecules. At certain temperatures and pressures, the polyradicals undergo ring-opening reactions, which fuel a series of rapid exothermic chemical reactions leading to a thermal runaway regime with stable gas-products such as N2, H2O and CO2. The evolution of the RDX crystal throughout the thermal initiation, incubation and thermal runaway phases observed in the reactive simulations contains a rich diversity of condensed-phase chemistry of nitramines under high-temperature/pressure conditions.

Soil dioxins levels at agriculture sites and natural preserve areas of Taiwan.

Science.gov (United States)

Jou, Jin-juh; Lin, Kae-Long; Chung, Jen-Chir; Liaw, Shu-Liang

2007-08-17

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.

Ractopamine up take by alfalfa (Medicago sativa) and wheat (Triticum aestivum) from soil.

Science.gov (United States)

Shelver, Weilin L; DeSutter, Thomas M

2015-08-01

Ractopamine is a beta adrenergic agonist used as a growth promoter in swine, cattle and turkeys. To test whether ractopamine has the potential to accumulate in plants grown in contaminated soil, a greenhouse study was conducted with alfalfa (Medicago sativa) and wheat (Triticum aestivum) grown in two soils having different concentrations of organic matter (1.3% and 2.1%), amended with 0, 0.5, and 10 μg/g of ractopamine. Plant growth ranged from 2.7 to 8.8 g dry weight (dw) for alfalfa, and 8.7 to 40 g dw for wheat and was generally greater in the higher organic matter content soil. The uptake of ractopamine in plant tissues ranged from non-detectable to 897 ng/g and was strongly dependent on soil ractopamine concentration across soil and plant tissue. When adjusted to the total fortified quantities, the amount of ractopamine taken up by the plant tissue was low, <0.01% for either soil. Copyright © 2015. Published by Elsevier B.V.

[Distribution of HCB discharged from a chemical plant in plants].

Science.gov (United States)

Chen, Jing; Wang, Lin-Ling; Lu, Xiao-Hua; Yuan, Song-Hu; Liu, Xi-Xiang; Wang, Yue; Zhao, Qian; Mei, Ling-Fang

2009-04-15

The distribution characteristics of hexachlorobenzene (HCB) in plant and rhizosphere soil in contamination conduit, a nearby river and a cropland were studied and the impact factors were also discussed. The results are summarized as follows: the range of the HCB concentration in plant and rhizosphere soil in investigation area were respectively from 4.45 microg x kg(-1) to 1,189.89 microg x kg(-1) (dw) and from 27.93 microg x kg(-1) to 3,480.71 microg x kg(-1) (dw). Higher enrichment of HCB in woodplant than herbs due to higher fat concentration in woodplant in the contamination conduit and the rich concentrtion factor of woodplant and herbs were 0.41-2.55 and 0.01-1.34. The range of HCB concentrations in plants in nearby croplands was significantly wide (4.45-333.1 microg x kg(-1)) while HCB concentrations in different parts of plant were various, e.g. HCB concentrations in fruit, root and shoot of taro were 318.77 microg x kg(-1), 281.02 microg x kg(-1) and 10.94 microg x kg(-1). There was a remarkable positive relation between the concentrations of HCB in plant and fat concentration of plant while no relativity between the concentrations of HCB in plant and those in ground soils in the contamination conduit and cropland. The concentration levels of HCB in plant and rhizosphere soil in river were dramatically decreased with increasing distance from contaminated conduit. There was a remarkable positive relation between the concentrations of HCB in plant and those in ground soils but no relation between concentrations of HCB in plant and fat concentration of plant in river. The distribution characteristics of HCB in plants were influenced by contaminated levels, fat concentration and Partition-transfer model.

Measurement of technetium-99 in Marshall Islands soil samples by ICP-MS

Energy Technology Data Exchange (ETDEWEB)

Tagami, K. E-mail: k_tagami@nirs.go.jp; Uchida, S.; Hamilton, T.; Robison, W

2000-07-15

Extraction techniques for recovery of technetium-99 ({sup 99}Tc) for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) measurements were evaluated using soil samples collected from the Marshall Islands. The results of three different extraction techniques were compared: (M1) acid leaching of Tc from ashed soil; (M2) acid leaching of Tc from raw dry soil; and (M3) Tc volatilization from ashed soil using a combustion apparatus. Total Tc recoveries varied considerably between the extraction techniques but each method yielded similar analytical results for {sup 99}Tc. Applications of these extraction techniques to a series of environmental samples and ICP-MS measurements have yielded first data on the {sup 99}Tc content of Marshall Islands soil samples contaminated with close-in radioactive fallout from nuclear weapons testing. The {sup 99}Tc activity concentration in the soil samples ranged between 0.1 and 1.1 mBq g{sup -1} dry weight (dw). The limit of detection for {sup 99}Tc by ICP-MS was 0.17 mBq per sample or 0.014 mBq g{sup -1} dw under standard operating conditions.

Understanding metastable phase transformation during crystallization of RDX, HMX and CL-20: experimental and DFT studies.

Science.gov (United States)

Ghosh, Mrinal; Banerjee, Shaibal; Shafeeuulla Khan, Md Abdul; Sikder, Nirmala; Sikder, Arun Kanti

2016-09-14

Multiphase growth during crystallization severely affects deliverable output of explosive materials. Appearance and incomplete transformation of metastable phases are a major source of polymorphic impurities. This article presents a methodical and molecular level understanding of the metastable phase transformation mechanism during crystallization of cyclic nitramine explosives, viz. RDX, HMX and CL-20. Instantaneous reverse precipitation yielded metastable γ-HMX and β-CL-20 which undergo solution mediated transformation to the respective thermodynamic forms, β-HMX and ε-CL-20, following 'Ostwald's rule of stages'. However, no metastable phase, anticipated as β-RDX, was evidenced during precipitation of RDX, which rather directly yielded the thermodynamically stable α-phase. The γ→β-HMX and β→ε-CL-20 transformations took 20 and 60 minutes respectively, whereas formation of α-RDX was instantaneous. Density functional calculations were employed to identify the possible transition state conformations and to obtain activation barriers for transformations at wB97XD/6-311++G(d,p)(IEFPCM)//B3LYP/6-311G(d,p) level of theory. The computed activation barriers and lattice energies responsible for transformation of RDX, HMX and CL-20 metastable phases to thermodynamic ones conspicuously supported the experimentally observed order of phase stability. This precise result facilitated an understanding of the occurrence of a relatively more sensitive and less dense β-CL-20 phase in TNT based melt-cast explosive compositions, a persistent and critical problem unanswered in the literature. The crystalline material recovered from such compositions revealed a mixture of β- and ε-CL-20. However, similar compositions of RDX and HMX never showed any metastable phase. The relatively long stability with the highest activation barrier is believed to restrict complete β→ε-CL-20 transformation during processing. Therefore a method is suggested to overcome this issue.

Long-Term Persistence of Pesticides and TPs in Archived Agricultural Soil Samples and Comparison with Pesticide Application.

Science.gov (United States)

Chiaia-Hernandez, Aurea C; Keller, Armin; Wächter, Daniel; Steinlin, Christine; Camenzuli, Louise; Hollender, Juliane; Krauss, Martin

2017-09-19

For polar and more degradable pesticides, not many data on long-term persistence in soil under field conditions and real application practices exist. To assess the persistence of pesticides in soil, a multiple-compound screening method (log K ow 1.7-5.5) was developed based on pressurized liquid extraction, QuEChERS and LC-HRMS. The method was applied to study 80 polar pesticides and >90 transformation products (TPs) in archived topsoil samples from the Swiss Soil Monitoring Network (NABO) from 1995 to 2008 with known pesticide application patterns. The results reveal large variations between crop type and field sites. For the majority of the sites 10-15 pesticides were identified with a detection rate of 45% at concentrations between 1 and 330 μg/kg dw in soil. Furthermore, TPs were detected in 47% of the cases where the "parent-compound" was applied. Overall, residues of about 80% of all applied pesticides could be detected with half of these found as TPs with a persistence of more than a decade.

Effects of Aluminum Powder on Ignition Performance of RDX, HMX, and CL-20 Explosives

Directory of Open Access Journals (Sweden)

Xiaoxiang Mao

2018-01-01

Full Text Available As a kind of high explosives, aluminized explosive cannot release the energy maximumly, which is a key problem. Using DTA-TG equipment, the ignition performance of three kinds of aluminized explosives (RDX, HMX, and CL-20 with different mass percentages of aluminum powder (0%, 10 wt.%, 20 wt.%, and 30 wt.% was investigated. The results showed that the energy release of the HMX/Al composite explosive with 10 wt.%, 20 wt.%, and 30 wt.% aluminum powder was only equivalent to 80%, 65%, and 36% of pure HMX, respectively. It was similar to RDX/Al and CL-20/Al composite explosives, except the CL-20/Al mixture with 10% aluminum powder. Rather than participating in the ignition and combustion, the aluminum powder does effect the complete reaction of RDX, HMX, and CL-20 in the initial stage of ignition or in the lower temperature area of the boundary.

Use of dilute ammonia gas for treatment of 1,2,3-trichloropropane and explosives-contaminated soils.

Science.gov (United States)

Coyle, Charles G; Waisner, Scott A; Medina, Victor F; Griggs, Chris S

2017-12-15

Laboratory studies were performed to test a novel reactive gas process for in-situ treatment of soils containing halogenated propanes or explosives. A soil column study, using a 5% ammonia-in-air mixture, established that the treatment process can increase soil pH from 7.5 to 10.2. Batch reactor experiments were performed to demonstrate contaminant destruction in sealed jars exposed to ammonia. Comparison of results from batch reactors that were, and were not, exposed to ammonia demonstrated reductions in concentrations of 1,2,3-trichloropropane (TCP), 1,3-dichloropropane (1,3-DCP), 1,2-dicholoropropane (1,2-DCP) and dibromochloropropane (DBCP) that ranged from 34 to 94%. Decreases in TCP concentrations at 23° C ranged from 37 to 65%, versus 89-94% at 62° C. A spiked soil column study was also performed using the same set of contaminants. The study showed a pH penetration distance of 30 cm in a 2.5 cm diameter soil column (with a pH increase from 8 to > 10), due to treatment via 5% ammonia gas at 1 standard cubic centimeter per minute (sccm) for 7 days. Batch reactor tests using explosives contaminated soils exhibited a 97% decrease in 2,4,6-trinitrotoluene (TNT), an 83% decrease in nitrobenzene, and a 6% decrease in hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). A biotransformation study was also performed to investigate whether growth of ammonia-oxidizing microorganisms could be stimulated via prolonged exposure of soil to ammonia. Over the course of the 283 day study, only a very small amount of nitrite generation was observed; indicating very limited ammonia monooxygenase activity. Overall, the data indicate that ammonia gas addition can be a viable approach for treating halogenated propanes and some types of explosives in soils. Published by Elsevier Ltd.

Polychlorinated biphenyls in surface soil in urban and background areas of Mongolia

International Nuclear Information System (INIS)

Mamontova, Elena A.; Mamontov, Alexander A.; Tarasova, Eugenia N.; Kuzmin, Mikhail I.; Ganchimeg, Darmaa; Khomutova, Marina Yu.; Gombosuren, Odontuya; Ganjuurjav, Erdenebayasgalan

2013-01-01

Polychlorinated biphenyls (PCBs) were measured in soil in some industrial towns (Ulaanbaatar, Suhbaatar, Erdenet, Darhan, Tsetserleg, Hovd, Ulaangom, Altay, Bayanhongor, Arvayheer, Saynshand, Choybalsan) and in background and rural areas of Mongolia. The average sum of all investigated PCB congeners in soil of Mongolia comes to 7.4 ng/g dry weight (DW) and varies from 0.53 ng/g DW till 114 ng/g DW. PCB levels in soil from towns are significantly higher than those in soil from background and rural areas. The PCB homological composition in soil sampled in highly-PCB-polluted sites is similar to the PCB homological pattern in Sovol and Aroclor 1254. Significant correlation between soil organic carbon and low chlorinated PCB both for towns and background sites was found. Significant differences in PCB means in soil in different natural zones were found. -- Highlights: •First study to measure PCBs in surface soil sampled throughout Mongolia. •The PCB patterns in polluted soil were similar to those in Sovol or Aroclor 1254. •Significant differences in PCB means in soil in different natural zones were found. -- Polychlorinated biphenyls were measured in soils throughout Mongolia

Non-equilibrium dynamics due to moving deflagration front at RDX/HTPB interface

Science.gov (United States)

Chaudhuri, Santanu; Joshi, Kaushik; Lacevic, Naida

Reactive dissipative particle dynamics (DPD-RX), a promising tool in characterizing the sensitivity and performance of heterogeneous solid propellants like polymer bonded explosives (PSXs), requires further testing for non-equilibrium dynamics. It is important to understand detailed atomistic chemistry for developing coarse grain reactive models needed for the DPD-RX. In order to obtain insights into combustion chemistry of RDX/HTPB binder, we used reactive molecular dynamics (RMD) to obtain energy up-pumping and reaction mechanisms at RDX/HTPB interface when exposed to a self-sustaining deflagration front. Hot spots are ignited near and away from the heterogeneous interface using the thermal pulse. The results show that the hot spot near interface significantly delays the transition from ignition to deflagration. We will present the mechanical response and the combustion chemistry of HTPB when the propagating deflagration front hits the polymer binder. We will discuss our efforts to incorporate this RMD based chemistry into the DPD-RX which will enable us to perform such non-equilibrium dynamics simulations on large-length scale with microstructural heterogeneities. Funding from DTRA Grant Number HDTRA1-15-1-0034 is acknowledged.

CFD SIMULATION FOR DEMILITARIZATION OF RDX IN A ROTARY KILN BY THERMAL DECOMPOSITION

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SI H. LEE

2017-06-01

Full Text Available Demilitarization requires the recovery and disposal of obsolete ammunition and explosives. Since open burning/detonation of hazardous waste has caused serious environmental and safety problems, thermal decomposition has emerged as one of the most feasible methods. RDX is widely used as a military explosive due to its high melting temperature and detonation power. In this work, the feasible conditions under which explosives can be safely incinerated have been investigated via a rotary kiln simulation. To solve this problem, phase change along with the reactions of RDX has been incisively analyzed. A global reaction mechanism consisting of condensed phase and gas phase reactions are used in Computational Fluid Dynamics simulation. User Defined Functions in FLUENT is utilized in this study to inculcate the reactions and phase change into the simulation. The results divulge the effect of temperature and the varying amounts of gas produced in the rotary kiln during the thermal decomposition of RDX. The result leads to the prospect of demilitarizing waste explosives to avoid the possibility of detonation.

Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters

Science.gov (United States)

2009-12-01

ER D C TR -0 9- 10 Strategic Environmental Research and Development Program Phytoremediation of Composition-B Derived TNT and RDX in...Program ERDC TR-09-10 December 2009 Phytoremediation of Composition-B Derived TNT and RDX in Herbaceous Plant-vegetated and Bare Lysimeters Elly P. H...for U.S. Army Corps of Engineers Washington, DC 20314-1000 ERDC TR-09-10 ii Abstract: This report describes a study in which phytoremediation of

BIO-MONITORING FOR URANIUM USING STREAM-SIDE TERRESTRIAL PLANTS AND MACROPHYTES

Energy Technology Data Exchange (ETDEWEB)

Caldwell, E.; Duff, M.; Hicks, T.; Coughlin, D.; Hicks, R.; Dixon, E.

2012-01-12

This study evaluated the abilities of various plant species to act as bio-monitors for environmental uranium (U) contamination. Vegetation and soil samples were collected from a U processing facility. The water-way fed from facility storm and processing effluents was the focal sample site as it represented a primary U transport mechanism. Soils and sediments from areas exposed to contamination possessed U concentrations that averaged 630 mg U kg{sup -1}. Aquatic mosses proved to be exceptional accumulators of U with dry weight (dw) concentrations measuring as high as 12500 mg U kg{sup -1} (approximately 1% of the dw mass was attributable to U). The macrophytes (Phragmites communis, Scripus fontinalis and Sagittaria latifolia) were also effective accumulators of U. In general, plant roots possessed higher concentrations of U than associated upper portions of plants. For terrestrial plants, the roots of Impatiens capensis had the highest observed levels of U accumulation (1030 mg kg{sup -1}), followed by the roots of Cyperus esculentus and Solidago speciosa. The concentration ratio (CR) characterized dry weight (dw) vegetative U levels relative to that in associated dw soil. The plant species that accumulated U at levels in excess of that found in the soil were: P. communis root (CR, 17.4), I. capensis root (CR, 3.1) and S. fontinalis whole plant (CR, 1.4). Seven of the highest ten CR values were found in the roots. Correlations with concentrations of other metals with U were performed, which revealed that U concentrations in the plant were strongly correlated with nickel (Ni) concentrations (correlation: 0.992; r-squared: 0.984). Uranium in plant tissue was also strongly correlated with strontium (Sr) (correlation: 0.948; r-squared: 0.899). Strontium is chemically and physically similar to calcium (Ca) and magnesium (Mg), which were also positively-correlated with U. The correlation with U and these plant nutrient minerals, including iron (Fe), suggests that active

DW MRI at 3.0 T versus FDG PET/CT for detection of malignant pulmonary tumors.

Science.gov (United States)

Zhang, Jian; Cui, Long-Biao; Tang, Xing; Ren, Xin-Ling; Shi, Jie-Ran; Yang, Hai-Nan; Zhang, Yan; Li, Zhi-Kui; Wu, Chang-Gui; Jian, Wen; Zhao, Feng; Ti, Xin-Yu; Yin, Hong

2014-02-01

Emerging evidence suggests that diffusion-weighted magnetic resonance imaging (DW MRI) could be useful for tumor detection with N and M staging of lung cancer in place of fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). DW MRI at 3.0 T and FDG PET/CT were performed before therapy in 113 patients with pulmonary nodules. Mean apparent diffusion coefficient (ADC), maximal standardized uptake value (SUVmax ) and Ki-67 scores were assessed. Quantitatively, specificity and accuracy of ADC (91.7 and 92.9%, respectively) were significantly higher than those of SUVmax (66.7 and 77.9% respectively, p 0.05). Qualitatively, sensitivity, specificity and accuracy of DW MRI (96.1, 83.3 and 92.0%, respectively) were also not significantly different from that of FDG PET/CT (88.3, 83.3 and 86.7%, respectively, p > 0.05). Significant negative correlation was found between Ki-67 score and ADC (r = -0.66, p 0.05). In conclusion, quantitative and qualitative assessments for detection of malignant pulmonary tumors with DW MRI at 3.0 T are superior to those with FDG PET/CT. Furthermore, ADC could predict the malignancy of lung cancer. © 2013 UICC.

Soil-to-plant transfer factors of natural radionuclides (226Ra and 40K) in selected Thai medicinal plants.

Science.gov (United States)

Saenboonruang, Kiadtisak; Phonchanthuek, Endu; Prasandee, Kamonkhuan

2018-04-01

A soil-to-plant transfer factor (TF) is an important parameter that could be used to estimate radionuclides levels in medicinal plants. This work reports concentrations of natural radionuclides ( 226 Ra and 40 K) and TFs in six Thai medicinal plants grown in central Thailand using an HPGe gamma ray spectrometer. Either root, leaf, or flower parts of each medicinal plant were selected for use in the investigation according to their practical uses in traditional medicine. The results showed that due to K being essential in plants, 40 K had higher arithmetic means of activity concentrations and geometric means of TFs (geometric standard deviations in parentheses) of 610 ± 260 Bq kg -1 dry weight (DW) and 2.0 (1.4), respectively, than 226 Ra, which had the activity concentrations and TFs of 4.8 ± 2.6 Bq kg -1 DW and 0.17 (1.8), respectively. The results also showed that the leaves of medicinal plants had higher activity concentrations and TFs than root and flower parts, probably due to higher metabolic activities in leaves. Furthermore, there was good agreement between the results from the current work and other similar reports on medicinal plants. The information obtained from this work could strengthen knowledge of natural radionuclides in plants and particularly increase available TF data on Thai medicinal plants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Changes in the concentrations of phenolics and photosynthates in Scots pine (Pinus sylvestris L.) seedlings exposed to nickel and copper

Energy Technology Data Exchange (ETDEWEB)

Roitto, M. [MTT Agrifood Research Finland, Environmental Research, Karilantie 2A, FIN-50600 Mikkeli (Finland) and Department of Ecological and Environmental Sciences, University of Helsinki, Niemenkatu 73, FIN-15140 Lahti (Finland)]. E-mail: marja.roitto@mtt.fi; Rautio, P. [Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano (Finland); Julkunen-Tiitto, R. [Department of Biology, University of Joensuu, PO Box 111, FIN-80101 Joensuu (Finland); Kukkola, E. [University of Helsinki, Department of Biosciences, Division of Plant Physiology, PO Box 56, FIN-00014, Helsinki (Finland); Huttunen, S. [Department of Biology, University of Oulu, PO Box 3000, FIN-90014 Oulu (Finland)

2005-10-15

Studies were done on the effects of elevated soil concentrations of copper (Cu) and (Ni) on foliar carbohydrates and phenolics in Scots pine (Pinus sylvestris L.). Four year-old seedlings were planted in pots filled with metal-treated mineral forest soil in early June. The experimental design included all combinations of four levels of Cu (0, 25, 40 and 50 mg kg{sup -1} soil dw) and Ni (0, 5, 15 and 25 mg kg{sup -1} soil dw). Current year needles were sampled for soluble sugar, starch and phenolics at the end of September. Ni increased sucrose concentration in the needles, indicating disturbances in carbohydrate metabolism. Trees exposed to Ni had higher concentrations of condensed tannins compared with controls. In contrast, concentrations of several other phenolic compounds decreased when seedlings were exposed to high levels of Cu or to a combination of Ni and Cu. The results suggest that concentrations of phenolics in Scots pine needles vary in their responses to Ni and Cu in the forest soil. - Excess nickel in soil interferes with carbohydrate metabolism and induces an increase in concentration of condensed tannins in Scots pine needles.

Changes in the concentrations of phenolics and photosynthates in Scots pine (Pinus sylvestris L.) seedlings exposed to nickel and copper

International Nuclear Information System (INIS)

Roitto, M.; Rautio, P.; Julkunen-Tiitto, R.; Kukkola, E.; Huttunen, S.

2005-01-01

Studies were done on the effects of elevated soil concentrations of copper (Cu) and (Ni) on foliar carbohydrates and phenolics in Scots pine (Pinus sylvestris L.). Four year-old seedlings were planted in pots filled with metal-treated mineral forest soil in early June. The experimental design included all combinations of four levels of Cu (0, 25, 40 and 50 mg kg -1 soil dw) and Ni (0, 5, 15 and 25 mg kg -1 soil dw). Current year needles were sampled for soluble sugar, starch and phenolics at the end of September. Ni increased sucrose concentration in the needles, indicating disturbances in carbohydrate metabolism. Trees exposed to Ni had higher concentrations of condensed tannins compared with controls. In contrast, concentrations of several other phenolic compounds decreased when seedlings were exposed to high levels of Cu or to a combination of Ni and Cu. The results suggest that concentrations of phenolics in Scots pine needles vary in their responses to Ni and Cu in the forest soil. - Excess nickel in soil interferes with carbohydrate metabolism and induces an increase in concentration of condensed tannins in Scots pine needles

Combination of a Fast Cleanup Procedure and a DR-CALUX® Bioassay for Dioxin Surveillance in Taiwanese Soils

Science.gov (United States)

Lin, Ding-Yan; Lee, Yi-Pin; Li, Chiu-Ping; Chi, Kai-Hsien; Liang, Bo-Wei P.; Liu, Wen-Yao; Wang, Chih-Cheng; Lin, Susana; Chen, Ting-Chien; Yeh, Kuei-Jyum C.; Hsu, Ping-Chi; Hsu, Yi-Chyun; Chao, How-Ran; Tsou, Tsui-Chun

2014-01-01

Our goal was to determine dioxin levels in 800 soil samples collected from Taiwan. An in vitro DR-CALUX® assay was carried out with the help of an automated Soxhlet system and fast cleanup column. The mean dioxin level of 800 soil samples was 36.0 pg-bioanalytical equivalents (BEQs)/g dry weight (d.w.). Soil dioxin-BEQs were higher in northern Taiwan (61.8 pg-BEQ/g d.w.) than in central, southern, and eastern Taiwan (22.2, 24.9, and 7.80 pg-BEQ/g d.w., respectively). Analysis of multiple linear regression models identified four major predictors of dioxin-BEQs including soil sampling location (β = 0.097, p contamination. Soil samples collected in northern Taiwan, and especially in Bade City, soils near industrial areas, and soils with darker color may contain higher dioxin-BEQ levels. PMID:24806195

Determining the bioavailability and toxicity of lead contamination to earthworms requires using a combination of physicochemical and biological methods

International Nuclear Information System (INIS)

Luo, Wei; Verweij, Rudo A.; Gestel, Cornelis A.M. van

2014-01-01

This study aimed at assessing the bioavailability and toxicity of lead to Eisenia andrei in shooting range soils representing different land uses (forest, grassland, bullet plot). Soils contained 47–2398 mg Pb/kg dry weight (dw), but also had different pH-CaCl 2 (3.2–6.8) and organic matter contents (3.8–13%). Therefore artificial soils with different pH and organic matter contents and two natural soils were included as control soils. Earthworms were exposed for 28 days and toxicity and uptake of Pb were related to total, water and 0.01 M CaCl 2 extractable and porewater Pb concentrations as well as to soil characteristics. Pb uptake in the earthworms linearly increased with increasing soil concentrations. At >2000 mg Pb/kg dw and pH 3.3–3.5, high earthworm mortality with significant weight loss and complete inhibition of reproduction were recorded. At <1000 mg/kg dw, earthworm reproduction was more related to differences in pH and other soil characteristics than to Pb. -- Highlights: • Availability and earthworm toxicity of Pb determined in field-contaminated soils. • Earthworm toxicity of most-polluted soils explained from available Pb levels. • Earthworm response in less polluted soils mainly determined by soil pH. • Earthworm toxicity correlated with Pb uptake from the soil. • Soil properties explained differences in earthworm Pb uptake and effects. -- Combination of physicochemical and biological assays helped explaining Pb toxicity in shooting range soils from available Pb concentrations and soil characteristics

Methane oxidation in a landfill cover soil reactor: Changing of kinetic parameters and microorganism community structure.

Science.gov (United States)

Xing, Zhi L; Zhao, Tian T; Gao, Yan H; Yang, Xu; Liu, Shuai; Peng, Xu Y

2017-02-23

Changing of CH 4 oxidation potential and biological characteristics with CH 4 concentration was studied in a landfill cover soil reactor (LCSR). The maximum rate of CH 4 oxidation reached 32.40 mol d -1 m -2 by providing sufficient O 2 in the LCSR. The kinetic parameters of methane oxidation in landfill cover soil were obtained by fitting substrate diffusion and consumption model based on the concentration profile of CH 4 and O 2 . The values of [Formula: see text] (0.93-2.29%) and [Formula: see text] (140-524 nmol kg soil-DW -1 ·s -1 ) increased with CH 4 concentration (9.25-20.30%), while the values of [Formula: see text] (312.9-2.6%) and [Formula: see text] (1.3 × 10 -5 to 9.0 × 10 -3 nmol mL -1 h -1 ) were just the opposite. MiSeq pyrosequencing data revealed that Methylobacter (the relative abundance was decreased with height of LCSR) and Methylococcales_unclassified (the relative abundance was increased expect in H 80) became the key players after incubation with increasing CH 4 concentration. These findings provide information for assessing CH 4 oxidation potential and changing of biological characteristics in landfill cover soil.

Twiny pro: 5.1 kg of propane dressed in apple green; Twiny pro: 5.1 kg de propane en habillage vert pomme

Energy Technology Data Exchange (ETDEWEB)

Anon.

1998-05-01

Designed for professional and outdoors uses, Twini Pro - the new Primagaz 5.1 kg propane cylinder - is a complement to the Twiny butane 6 kg cylinder was launched during the first week of March in some 2,500 outlets, before 5,000 and 7,000 points later

Contamination of Phthalate Esters (PAEs in Typical Wastewater-Irrigated Agricultural Soils in Hebei, North China.

Directory of Open Access Journals (Sweden)

Yuan Zhang

Full Text Available The Wangyang River (WYR basin is a typical wastewater irrigation area in Hebei Province, North China. This study investigated the concentration and distribution of six priority phthalate esters (PAEs in the agricultural soils in this area. Thirty-nine soil samples (0-20 cm were collected along the WYR to assess the PAE residues in soils. Results showed that PAEs are ubiquitous environmental contaminants in the topsoil obtained from the irrigation area. The concentrations of Σ6PAEs range from 0.191 μg g-1 dw to 0.457 μg g-1 dw with an average value of 0.294 μg g-1 dw. Di(2-ethylhexyl phthalate (DEHP and di-n-butyl phthalate (DnBP are the dominant PAE species in the agricultural soils. Among the DEHP concentrations, the highest DEHP concentration was found at the sites close to the villages; this result suggested that dense anthropogenic activities and random garbage disposal in the rural area are possible sources of PAEs. The PAE concentrations were weakly and positively correlated with soil organic carbon and soil enzyme activities; thus, these factors can affect the distribution of PAEs. This study further showed that only dimethyl phthalate (DMP concentrations exceeded the recommended allowable concentrations; no remediation measures are necessary to control the PAEs in the WYR area. However, the PAEs in the topsoil may pose a potential risk to the ecosystem and human health in this area. Therefore, the exacerbating PAE pollution should be addressed.

Surface effects on the crystallization of cyclo-1,3,5-trimethylene-2,4,6-trinitramine (RDX) and the consequences for its N K X-ray emission spectrum.

Science.gov (United States)

Goldberg, Ilana G; Vila, Fernando D; Jach, Terrence

2012-10-11

Recent studies of the crystallization of cyclotrimethylene-trinitramine (RDX) have shown that the presence of the α- and β-phases of the compound is sensitive to the substrate when using drop cast crystallization methods. The specific phase has potential consequences for measurements of the nitrogen K X-ray emission spectrum (XES) that were recently reported for this compound using samples crystallized on In metal substrates. We have determined that the crystallization of RDX on a clean In metal substrate starts out completely as the β-phase but progressively incorporates the α-phase as the film thickens. In addition, we have carried out additional molecular orbital calculations of the N 1s X-ray fluorescence from the valence band, comparing the results expected from the α-and β- phases. The differences due to the presence of the β-phase instead of, or in addition to, the α-phase appear to be minimal.

Dose of rocuronium for rapid tracheal intubation following remifentanil 2 μg kg-1 and propofol 2 mg kg-1.

Science.gov (United States)

Oh, Ah-Young; Cho, Suk-Ju; Seo, Kwang-Suk; Ryu, Jung-Hee; Han, Sung-Hee; Hwang, Jung-Won

2013-09-01

Full relaxation is not mandatory for successful tracheal intubation. We tried to find the dose of rocuronium that gave acceptable intubation conditions in a rapid sequence intubation with remifentanil and propofol. A dose-finding study of rocuronium using a modified Dixon's up-and-down method. A single tertiary care teaching hospital. Patients undergoing elective surgery under general anaesthesia. After premedication with midazolam and glycopyrrolate, anaesthesia was induced using remifentanil 2 μg kg and propofol 2 mg kg, and a predetermined dose of rocuronium was administered. The dose of rocuronium was determined by a modified Dixon's up-and-down method starting from 0.8 mg kg with an interval of 0.1 or 0.05 mg kg. Intubation was performed 60 s after the start of the rocuronium injection. Intubation conditions were graded as excellent, good or poor. Excellent or good were regarded as clinically acceptable. A dose of rocuronium needed for acceptable intubation condition in 50% of patients (ED50) during rapid tracheal intubation after induction of anaesthesia with remifentanil and propofol. Twenty-eight patients were enrolled to obtain six crossovers. The ED50 of rocuronium was 0.20 mg kg (95% confidence interval, CI 0.17 to 0.23 mg kg) by a modified Dixon's up-and-down method. After induction of anaesthesia with remifentanil 2 μg kg and propofol 2 mg kg, the ED50 of rocuronium for acceptable intubation condition was 0.20 mg kg (95% CI, 0.17 to 0.23 mg kg) for rapid sequence intubation. Thus, we recommend that the intubation dose should be 0.8 mg kg. Clinical trial registration KCT0000094.

DW4TR: A Data Warehouse for Translational Research.

Science.gov (United States)

Hu, Hai; Correll, Mick; Kvecher, Leonid; Osmond, Michelle; Clark, Jim; Bekhash, Anthony; Schwab, Gwendolyn; Gao, De; Gao, Jun; Kubatin, Vladimir; Shriver, Craig D; Hooke, Jeffrey A; Maxwell, Larry G; Kovatich, Albert J; Sheldon, Jonathan G; Liebman, Michael N; Mural, Richard J

2011-12-01

The linkage between the clinical and laboratory research domains is a key issue in translational research. Integration of clinicopathologic data alone is a major task given the number of data elements involved. For a translational research environment, it is critical to make these data usable at the point-of-need. Individual systems have been developed to meet the needs of particular projects though the need for a generalizable system has been recognized. Increased use of Electronic Medical Record data in translational research will demand generalizing the system for integrating clinical data to support the study of a broad range of human diseases. To ultimately satisfy these needs, we have developed a system to support multiple translational research projects. This system, the Data Warehouse for Translational Research (DW4TR), is based on a light-weight, patient-centric modularly-structured clinical data model and a specimen-centric molecular data model. The temporal relationships of the data are also part of the model. The data are accessed through an interface composed of an Aggregated Biomedical-Information Browser (ABB) and an Individual Subject Information Viewer (ISIV) which target general users. The system was developed to support a breast cancer translational research program and has been extended to support a gynecological disease program. Further extensions of the DW4TR are underway. We believe that the DW4TR will play an important role in translational research across multiple disease types. Copyright © 2011 Elsevier Inc. All rights reserved.

Sustainable Range Management of RDX and TNT by Phytoremediation with Engineered Plants

Science.gov (United States)

2016-04-01

pH 6.5. Change in absorbance at 340 nm was measured over 1 min. Significant difference from wild-type (WT) is shown by an asterisk and determined by...FINAL REPORT Sustainable Range Management of RDX and TNT by Phytoremediation with Engineered Plants SERDP Project ER-1498 APRIL 2016...by Phyoremediation with Engineered Plants 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER ER-1498 Neil C

Effect of EDTA on Pb(II) Uptake and Translocation by Tumbleweed (Salsola Kali): Agar and Hydroponics Studies

Energy Technology Data Exchange (ETDEWEB)

de la Rosa, Guadalupe; Gardea-Torresdey, Jorge L.; Peralta-Videa, Jose R.; Aldrich, Mary

2004-03-31

Environmental accumulation of Pb represents a worldwide health hazard. While conventional cleanup techniques are generally expensive and soil disturbing, phytoremediation represents an inexpensive friendly option for the removal of contaminants from soil and water. In this research, tumbleweed (Salsola kali) plants exposed for 15 days to Pb(NO3)2 at 80 and 125 ppm in hydroponics and agar media, demonstrated a high capacity to uptake lead. The results showed that the plants cultivated in agar accumulated 25563, 5534 and 2185 mg Pb kg-1 DW in roots, stems and leaves, respectively. Moreover, Pb concentrations found in hydroponically grown tumbleweed plants tissues were 30744, 1511 and 1421 mg kg-1 DW in roots, stems and leaves, respectively. It was observed that EDTA enhanced Pb translocation. No Pb phytotoxic effects were observed during the experimental time period. Cellular structural features were also observed using TEM.

Untangling the transcription regulatory network of the bacitracin synthase operon in Bacillus licheniformis DW2.

Science.gov (United States)

Wang, Dong; Wang, Qin; Qiu, Yimin; Nomura, Christopher T; Li, Junhui; Chen, Shouwen

The bacitracin synthetase gene cluster in Bacillus licheniformis DW2 is composed of the bacABC operon encoding a non-ribosomal peptide synthetase and bacT encoding a thioesterase. Although the bacitracin gene cluster has been well studied, little is known about how this gene cluster is regulated. This study provides insight into how the transcription factors Spo0A and AbrB regulate bacitracin biosynthesis. Deletion of spo0A resulted in drastically reduced expression of bacA and bacT, and subsequently bacitracin production. On the other hand, the expression of bacA and bacT increased significantly in B. licheniformis DW2ΔabrB and DW2Δ0AΔabrB compared to the wild-type strain DW2. The bacitracin yields on cell numbers (U/CFU) in DW2ΔabrB and DW2Δ0A/pHY300-0A-sad67 were 17.5% and 14.9% higher than that of the wild-type strain. An electrophoretic mobility shift assay (EMSA) further confirmed that AbrB could directly bind to the promoter regions of bacA and bacT. These results indicate that AbrB acts as a repressor of bacitracin biosynthesis by inhibiting bacA and bacT expression, while Spo0A indirectly promotes bacitracin biosynthesis by repressing abrB expression. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Lon protease affects the RdxA nitroreductase activity and metronidazole susceptibility in Helicobacter pylori.

Science.gov (United States)

Tu, I-Fan; Liao, Jiahn-Haur; Yang, Feng-Ling; Lin, Nien-Tsung; Chan, Hong-Lin; Wu, Shih-Hsiung

2014-10-01

The lon gene of Helicobacter pylori strains is constitutively expressed during growth. However, virtually nothing is understood concerning the role of Lon in H. pylori. This study examined the function and physiological role of Lon in H. pylori (HpLon) using a trapping approach to identify putative Lon binding partners in the bacterium. Protease-deficient Lon was expressed and served as the bait in trapping approach to capture the interacting partners in H. pylori. The antibiotic susceptibility of wild-type and lon derivative mutants was determined by the E test trips and the disc diffusion assay. The effect of HpLon on RdxA activity was detected the change in NADPH oxidation and metronidazole reduction by spectrophotometer. Lon in Helicobacter pylori (HpLon) interacting partners are mostly associated with metronidazole activation. lon mutant presents more susceptible to metronidazole than that of the wild type, and this phenotype is recovered by complementation of the wild-type Lon. We found that the ATPases associated with a variety of cellular activities (AAA(+) ) module of HpLon causes a decrease in both NADPH oxidase and Mtz reductase activity in RdxA, a major Mtz-activating enzyme in H. pylori. Metronidazole resistance of H. pylori causes the serious medical problem worldwide. In this study, HpLon is involved in metronidazole susceptibility among H. pylori strains. We provide the evidence that HpLon alters RdxA activity in vitro. The decrease in metronidazole activation caused by HpLon is possibly prior to accumulate mutation in rdxA gene before the metronidazole-resistant strains to be occurred. © 2014 John Wiley & Sons Ltd.

(Bio)degradation of RDX and HMX in Marine/Estuarine Water and Sediments

Science.gov (United States)

2006-09-01

four fungal strains Rhodotorula sp . HAW-OCF1, Bullera sp . HAW-OCF2, Acremonium sp . HAW-OCF3 and Penicillium sp . HAW-OCF5, were isolated as RDX...represent four novel species of Shewanella described as follows: Shewanella sediminis sp . nov.: Strain HAW-EB3T contains lysine decarboxylase that is...We proposed Shewanella sediminis sp . nov. with HAW-EB3T (= NCIMB 14036T = DSM 17055T) as the type strain (Zhao et al. 2005). Shewanella halifaxensis

Evaluation of the transfer and the accumulation of microcystins in tomato (Solanum lycopersicum cultivar MicroTom) tissues using a cyanobacterial extract containing microcystins and the radiolabeled microcystin-LR ("1"4C-MC-LR)

International Nuclear Information System (INIS)

Corbel, Sylvain; Mougin, Christian; Nélieu, Sylvie; Delarue, Ghislaine; Bouaïcha, Noureddine

2016-01-01

Microcystins are the most common cyanotoxins and may be expected wherever blooms of cyanobacteria occur in surface waters. Their persistence both in the irrigation water and in the soil can lead to their transfer and bioaccumulation into agricultural plants. The aim of this work was to investigate microcystin accumulation in Solanum lycopersicum cultivar MicroTom. The plant was exposed to either Microcystis aeruginosa crude extracts containing up to 100 μg eq. MC-LR L"−"1 in a soil–plant system for 90 days or pure radiolabeled "1"4C-MC-LR in a hydroponic condition for 48 h. Toxin bioaccumulation in the soil and different plant tissues was assessed both by the PP2A inhibition assay and by liquid chromatography-mass spectrometry (LC/MS/MS). After 90 days of exposure, microcystins persisted in the soil and their free extractable concentrations accumulated were very low varying between 1.6 and 3.9 μg eq. MC-LR kg"−"1 DW. Free MC-LR was detected only in roots and leaves with concentrations varying between 4.5 and 8.1 μg kg"−"1 DW and between 0.29 and 0.55 μg kg"−"1 DW, respectively. By using radioactivity ("1"4C-MC-LR), the results have reported a growing accumulation of toxins within the organs roots > leaves > stems and allowed them to confirm the absence of MC-LR in fruits after 48 h of exposure. The bioconcentration factor (BCF) was 13.6 in roots, 4.5 in leaves, and 1.4 in stems. On the other hand, the results highlight the presence of two radioactive fractions in different plant tissues. The non-extractable fraction of radioactivity, corresponding to the covalently bound MC-LR, was higher than that of the extractable fraction only in roots and leaves reaching 56% and 71% of the total accumulated toxin, respectively. Therefore, results raise that monitoring programs must monitor the presence of MCs in the irrigation water to avoid the transfer and accumulation of these toxins in crops. - Graphical abstract: Bioconcentration factors in organs of the

Phthalate esters contamination in soil and plants on agricultural land near an electronic waste recycling site.

Science.gov (United States)

Ma, Ting Ting; Christie, Peter; Luo, Yong Ming; Teng, Ying

2013-08-01

The accumulation of phthalic acid esters (PAEs) in soil and plants in agricultural land near an electronic waste recycling site in east China has become a great threat to the neighboring environmental quality and human health. Soil and plant samples collected from land under different utilization, including fallow plots, vegetable plots, plots with alfalfa (Medicago sativa L.) as green manure, fallow plots under long-term flooding and fallow plots under alternating wet and dry periods, together with plant samples from relative plots were analyzed for six PAE compounds nominated as prior pollutants by USEPA. In the determined samples, the concentrations of six target PAE pollutants ranged from 0.31-2.39 mg/kg in soil to 1.81-5.77 mg/kg in various plants (dry weight/DW), and their bioconcentration factors (BCFs) ranged from 5.8 to 17.9. Health risk assessments were conducted on target PAEs, known as typical environmental estrogen analogs, based on their accumulation in the edible parts of vegetables. Preliminary risk assessment to human health from soil and daily vegetable intake indicated that DEHP may present a high-exposure risk on all ages of the population in the area by soil ingestion or vegetable consumption. The potential damage that the target PAE compounds may pose to human health should be taken into account in further comprehensive risk assessments in e-waste recycling sites areas. Moreover, alfalfa removed substantial amounts of PAEs from the soil, and its use can be considered a good strategy for in situ remediation of PAEs.

Effect of Medicago sativa L. and compost on organic and inorganic pollutant removal from a mixed contaminated soil and risk assessment using ecotoxicological tests.

Science.gov (United States)

Marchand, Charlotte; Hogland, William; Kaczala, Fabio; Jani, Yahya; Marchand, Lilian; Augustsson, Anna; Hijri, Mohamed

2016-11-01

Several Gentle Remediation Options (GRO), e.g., plant-based options (phytoremediation), singly and combined with soil amendments, can be simultaneously efficient for degrading organic pollutants and either stabilizing or extracting trace elements (TEs). Here, a 5-month greenhouse trial was performed to test the efficiency of Medicago sativa L., singly and combined with a compost addition (30% w/w), to treat soils contaminated by petroleum hydrocarbons (PHC), Co and Pb collected at an auto scrap yard. After 5 months, total soil Pb significantly decreased in the compost-amended soil planted with M. sativa, but not total soil Co. Compost incorporation into the soil promoted PHC degradation, M. sativa growth and survival, and shoot Pb concentrations [3.8 mg kg(-1) dry weight (DW)]. Residual risk assessment after the phytoremediation trial showed a positive effect of compost amendment on plant growth and earthworm development. The O2 uptake by soil microorganisms was lower in the compost-amended soil, suggesting a decrease in microbial activity. This study underlined the benefits of the phytoremediation option based on M. sativa cultivation and compost amendment for remediating PHC- and Pb-contaminated soils.

Radioecological investigations in the food-chain air-soil-vine-wine. Pt. 1

International Nuclear Information System (INIS)

Wagner, A.; Hellmuth, K.H.; Fischer, E.

1988-12-01

In a field investigation (1983-1985) comprising 8 locations of the most important viticultural regions in Germany, the contents of H-3, C-14, Sr-90, and Cs-137 in air, soils, leaves of the vine, grapes and wine were measured and site-specific transfer factors were calculated. Data concerning soil parameters, climatic conditions, cultivation and vinification were collected. The T contents of all samples were 10 Bq/l water of combustion, independent of location and year. The specific activity of C-14 in the atmosphere and in biological material was 0.22 Bq/g C, independent of site and year. Sr-90 contents of soils fluctuated between 0.7 and 3.5 Bq/kg dry matter. The mean content of leaves was 2 Bq/kg fresh material, of grapes 0.035 Bq/kg and of wine 0.008 Bq/l. The Cs-137 level of soils fluctuated between 1.3 and 7.9 Bq/kg dry matter. The mean content of leaves was 0.098 Bq/kg fresh material, of grapes 0.021 Bq/kg and of wine 0.0085 Bq/l. A relation between transfer and soil parameters and between the contents of grapes and wine was not recognizeable. While cultivar-specific differences were not observed in grapes, red wines contained somewhat more Cs-137 than white wines. Transfer factors soil-grapes were 0.027 for Sr-90 and 0.0057 for Cs-137. Site-specific influences such as soil parameters, climate, cultivation, vinification and differences between years led to a small fluctuation of values. No influence of the Neckarwestheim reactor has been found in any of the radionuclides. (orig./HP) [de

Polonium-210 and Caesium-137 in lynx (Lynx lynx), wolverine (Gulo gulo) and wolves (Canis lupus).

Science.gov (United States)

Gjelsvik, Runhild; Holm, Elis; Kålås, John Atle; Persson, Bertil; Asbrink, Jessica

2014-12-01

Wolves, lynx and wolverines are on the top of the food-chain in northern Scandinavia and Finland. (210)Po and (137)Cs have been analysed in samples of liver, kidney and muscle from 28 wolves from Sweden. In addition blood samples were taken from 27 wolves. In 9 of the wolves, samples of muscle, liver and blood were analysed for (210)Po. Samples of liver and muscle were collected from 16 lynx and 16 wolverines from Norway. The liver samples were analysed for (210)Po and (137)Cs. Only (137)Cs analyses were carried out for the muscle samples. The wolves were collected during the winter 2010 and 2011, while the samples for lynx and wolverines were all from 2011. The activity concentrations of (210)Po in wolves were higher for liver (range 20-523 Bq kg(-1) d.w.) and kidney (range 24-942 Bq kg(-1) d.w.) than muscle (range 1-43 Bq kg(-1) d.w.) and blood (range 2-54 Bq kg(-1) d.w.). Activity ratios, (210)Po/(210)Pb, in wolf samples of muscle, liver and blood were in the ranges 2-77, 9-56 and 2-54. Using a wet weight ratio of 3.8 the maximal absorbed dose from (210)Po to wolf liver was estimated to 3500 μGy per year. Compared to wolf, the ranges of (210)Po in liver samples were lower in lynx (range 22-211 Bq kg(-1) d.w.) and wolverine (range16-160 Bq kg(-1) d.w.). Concentration of (137)Cs in wolf samples of muscle, liver, kidney and blood were in the ranges 70-8410 Bq kg(-1) d.w., 36-4050 Bq kg(-1) d.w., 31-3453 Bq kg(-1) d.w. and 4-959 Bq kg(-1) d.w., respectively. (137)Cs in lynx muscle and liver samples were in the ranges 44-13393 Bq kg(-1) d.w. and 125-10260 Bq kg(-1) d.w. The corresponding values for (137)Cs in wolverine were 22-3405 Bq kg(-1) d.w. for liver and 53-4780 Bq kg(-1) d.w. for muscle. The maximal absorbed dose from (137)Cs to lynx was estimated to 3000 μGy per year. Copyright © 2014 Elsevier Ltd. All rights reserved.

Ecological Risk of Heavy Metals and a Metalloid in Agricultural Soils in Tarkwa, Ghana

Science.gov (United States)

Bortey-Sam, Nesta; Nakayama, Shouta M. M.; Akoto, Osei; Ikenaka, Yoshinori; Baidoo, Elvis; Mizukawa, Hazuki; Ishizuka, Mayumi

2015-01-01

Heavy metals and a metalloid in agricultural soils in 19 communities in Tarkwa were analyzed to assess the potential ecological risk. A total of 147 soil samples were collected in June, 2012 and analyzed for As, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn. Mean concentrations (mg/kg dw) of heavy metals in the communities decreased in order of Zn (39) ˃ Cr (21) ˃ Pb (7.2) ˃ Cu (6.2) ˃ As (4.4) ˃ Ni (3.7) ˃ Co (1.8) ˃ Hg (0.32) ˃ Cd (0.050). Correlations among heavy metals and soil properties indicated that soil organic matter could have substantial influence on the total contents of these metals in soil. From the results, integrated pollution (Cdeg) in some communities such as, Wangarakrom (11), Badukrom (13) and T–Tamso (17) indicated high pollution with toxic metals, especially from As and Hg. Potential ecological risk (RI) indices indicated low (Mile 7) to high risks (Wangarakrom; Badukrom) of metals. Based on pollution coefficient (Cif), Cdeg, monomial ecological risk (Eir) and RI, the investigated soils fall within low to high contamination and risk of heavy metals to the ecological system especially plants, soil invertebrates and/or mammalian wildlife. This represented moderate potential ecological risk in the study area, and mining activities have played a significant role. PMID:26378563

Pesticide residues in nut-planted soils of China and their relationship between nut/soil.

Science.gov (United States)

Han, Yongxiang; Mo, Runhong; Yuan, Xinyue; Zhong, Donglian; Tang, Fubin; Ye, Caifen; Liu, Yihua

2017-08-01

Twenty-nine pesticide residues in nut-planted soils from China were investigated. One organophosphate (chlorpyrifos) was detected in 5.3% soils, and the residue levels of 7.2 μg/kg to 77.2 μg/kg. The concentrations of six organochlorines (DDT, HCH, endosulfan, quintozene, aldrin and dieldrin) detected in 78.9% soils were 0.6 μg/kg to 90.1 μg/kg. The residue levels of six pyrethroids (bifenthrin, fenpropathrin, cyhalothrin, cypermethrin, fenvalerate and deltamethrin) detected in 65.8% soils were 1.5 μg/kg to 884.3 μg/kg. Triadimefon and buprofezin were found in 71.1% and 52.6% samples, respectively, with the corresponding concentrations of 9.8 μg/kg to 193.7 μg/kg and 87.9 μg/kg to 807.4 μg/kg. The multiple residues were found in 76.3% soils. A significant correlation between pesticide residues in nuts and soils was observed, with the correlation coefficient (r) 0.83 (P < 0.001). In addition, the bioconcentration factor (BCF) values for the explanation of pesticides from soils into nuts were ranged from 0.8 to 16.5. The results showed that some pesticides could accumulate in nut by the uptake effect from soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

Random comparison study of the clinical response to 153Sm-EDTMP 1.0 mCi/kg and 1.5 mCi/kg

International Nuclear Information System (INIS)

Pan, Z.; Zhu, S.

2001-01-01

Sixty-seven patient with painful bone metastases were randomized to two groups. Group 1 (n=34) received 1.0 mCi/kg of 153 Sm-EDTMP and group II (n=33) received 1.5 mCi/kg. All of them met inclusion criteria and there was no significantly difference between the basic conditions of two groups. After receiving 153 Sm-EDTMP intravenously, all patients were kept in close follow-up weekly with blood counting, physician visiting and collecting patient's self-filling-in diary including pain score, Karnofsky performance scale and analgesic consumption. The follow-up duration was six weeks. The final overall condition assessed by physician were graded into no change (including worse), slight relief, significant relief and complete relief. Only significant relief and complete relief were considered as effectiveness for pain relief. Haematological toxicity grade was evaluated based on the nadir of WBC ad PLT counts. The results indicated that the higher dosage group had a higher effectiveness rate (75.76%) compared to the lower dosage group (67.65%), but without statistic significance (x 2 =0.5365, 0.25 153 Sm-EDTMP could be used for those patients with better haematological function and 1.0 mCi/kg used for those patients with poorer haematological function. (author)

Toxicological effects, mechanisms, and implied toxicity thresholds in the roots of Vicia faba L. seedlings grown in copper-contaminated soil.

Science.gov (United States)

Xu, Xianghua; Huang, Zhicheng; Wang, Chengrun; Zhong, Li; Tian, Yuan; Li, Dongdong; Zhang, Gaojian; Shi, Jian

2015-09-01

Copper (Cu) contamination has become a global concern because of industrial, agricultural, and other anthropogenic activities. In the present experiments, the toxicological effects, mechanisms, and potential toxicity thresholds were investigated in the roots of Vicia faba L. seedlings that were cultivated in Cu-amended soils (0, 6.25, 12.5, 25, 50, 100, 200, 400, and 600 mg kg(-1)) for 20 days, based on an analysis of the soil physicochemical properties, native Cu, available Cu, and root-enriched Cu contents. The superoxide dismutase (SOD), ascorbate peroxidase (APX), and guaiacol peroxidase (POD) isozymes and activities, as well as glutathione (GSH) and heat shock protein 70 (HSP70), changed like biphasic dose-response curves, cooperating to control the redox homeostasis. The APX and POD enzymes exhibited enhanced activities and became H2O2 scavengers primarily when the catalase (CAT) activities tended to decrease. Endoprotease (EP) isozymes and activities might be enhanced to degrade carbonylated proteins and alleviate metabolic disturbance in the roots. Additionally, HSP70 may not be suitable as a biomarker for relatively higher soil Cu concentrations and relatively longer exposure times for the roots. As a result, the isozymes and activities of SOD, CAT, and EP, as well as GSH, can be adopted as the most sensitive biomarkers. The toxicity threshold is estimated as 0.76-1.21 mg kg(-1) of available Cu in the soils or 25.04-36.65 μg Cu g(-1) dry weights (DW) in the roots.

Plant tolerance to diesel minimizes its impact on soil microbial characteristics during rhizoremediation of diesel-contaminated soils

International Nuclear Information System (INIS)

Barrutia, O.; Garbisu, C.; Epelde, L.; Sampedro, M.C.; Goicolea, M.A.; Becerril, J.M.

2011-01-01

Soil contamination due to petroleum-derived products is an important environmental problem. We assessed the impacts of diesel oil on plants (Trifolium repens and Lolium perenne) and soil microbial community characteristics within the context of the rhizoremediation of contaminated soils. For this purpose, a diesel fuel spill on a grassland soil was simulated under pot conditions at a dose of 12,000 mg diesel kg -1 DW soil. Thirty days after diesel addition, T. repens (white clover) and L. perenne (perennial ryegrass) were sown in the pots and grown under greenhouse conditions (temperature 25/18 o C day/night, relative humidity 60/80% day/night and a photosynthetic photon flux density of 400 μmol photon m -2 s -1 ) for 5 months. A parallel set of unplanted pots was also included. Concentrations of n-alkanes in soil were determined as an indicator of diesel degradation. Seedling germination, plant growth, maximal photochemical efficiency of photosystem II (F v /F m ), pigment composition and lipophylic antioxidant content were determined to assess the impacts of diesel on the studied plants. Soil microbial community characteristics, such as enzyme and community-level physiological profiles, were also determined and used to calculate the soil quality index (SQI). The presence of plants had a stimulatory effect on soil microbial activity. L. perenne was far more tolerant to diesel contamination than T. repens. Diesel contamination affected soil microbial characteristics, although its impact was less pronounced in the rhizosphere of L. perenne. Rhizoremediation with T. repens and L. perenne resulted in a similar reduction of total n-alkanes concentration. However, values of the soil microbial parameters and the SQI showed that the more tolerant species (L. perenne) was able to better maintain its rhizosphere characteristics when growing in diesel-contaminated soil, suggesting a better soil health. We concluded that plant tolerance is of crucial importance for the

Potential of Ranunculus acris L. for biomonitoring trace element contamination of riverbank soils: photosystem II activity and phenotypic responses for two soil series.

Science.gov (United States)

Marchand, Lilian; Lamy, Pierre; Bert, Valerie; Quintela-Sabaris, Celestino; Mench, Michel

2016-02-01

Foliar ionome, photosystem II activity, and leaf growth parameters of Ranunculus acris L., a potential biomonitor of trace element (TE) contamination and phytoavailability, were assessed using two riverbank soil series. R. acris was cultivated on two potted soil series obtained by mixing a TE (Cd, Cu, Pb, and Zn)-contaminated technosol with either an uncontaminated sandy riverbank soil (A) or a silty clay one slightly contaminated by TE (B). Trace elements concentrations in the soil-pore water and the leaves, leaf dry weight (DW) yield, total leaf area (TLA), specific leaf area (SLA), and photosystem II activity were measured for both soil series after a 50-day growth period. As soil contamination increased, changes in soluble TE concentrations depended on soil texture. Increase in total soil TE did not affect the leaf DW yield, the TLA, the SLA, and the photosystem II activity of R. acris over the 50-day exposure. The foliar ionome did not reflect the total and soluble TE concentrations in both soil series. Foliar ionome of R. acris was only effective to biomonitor total and soluble soil Na concentrations in both soil series and total and soluble soil Mo concentrations in the soil series B.

Effect of Plant Growth Promoting Rhizobacteria on the Concentration and Uptake of Macro Nutrients by Corn in a Cd-contaminated Calcareous Soil under Drought Stress

Directory of Open Access Journals (Sweden)

shahrzad karami

2017-02-01

Full Text Available Introduction: Heavy metals such as cadmium (Cd are found naturally in soils, but their amount can be changed by human activities. The study of the uptake and accumulation of heavy metals by plants is done in order to prevent their threats on human and animal’s health.Cadmium is a toxic element for living organisms. Cadmium competes with many of nutrients to be absorbed by the plant and interferes with their biological roles. Water stress affects the cell structure and the food is diverted from its normal metabolic pathway. It also reduces the availability and uptake of nutrients by the plant. One reason for the reduction of plant growth under drought stress is the accumulation of ethylene in plants. There are ways to mitigate the negative effects of drought stress that one of which is the use of Plant Growth Promoting Rhizobacteria(PGPRs to increasing the availability of nutrients. Soil beneficial bacteria play an important role in the biological cycles and have been used to increase plant health and soil fertility over the past few decades.The aim of this study was to investigate theeffect of PGPRson the concentration and uptake of macro nutrients by corn in a Cd-contaminated calcareous soil under drought stress. Materials and Methods: A greenhouse factorial experiment was conducted in a completely randomized design with three replications. The treatments were two levels of bacteria (with and without bacteria, four levels of Cd (5, 10, 20, and 40 mg kg-1, and three levels of drought stress (without stress, 80, and 65% of field capacity. The pots were filled with 3 kg of treated soil. Cd was treated as its sulfate salt in amounts of 5, 10, 20, and 40 mg kg-1. The soil was mixed uniformly with 150 mg N kg-1 as urea, 20 mg P kg-1 as Ca (H2PO42, 5 mg Fe kg-1 as Fe-EDDHA and 10, 10 and 2.5 mg Zn, Mn and Cu kg-1, respectively as their sulfate salt in order to meet plant needs for these nutrients. Six seeds of Zea mays (var. HIDO were planted at

Integrated Data Collection Analysis (IDCA) Program - RDX Type II Class 5 Standard, Data Set 1

Energy Technology Data Exchange (ETDEWEB)

Sandstrom, Mary M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brown, Geoffrey W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Preston, Daniel N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Pollard, Colin J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Warner, Kirstin F. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Sorenson, Daniel N. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Remmers, Daniel L. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Moran, Jesse S. [Naval Surface Warfare Center (NSWC), Indian Head, MD (United States). Indian Head Division; Shelley, Timothy J. [Air Force Research Lab. (AFRL), Tyndall AFB, FL (United States); Reyes, Jose A. [Applied Research Associates, Inc., Tyndall AFB, FL (United States); Hsu, Peter C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Whipple, Richard E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Reynolds, John G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2011-04-11

This document describes the results of the first reference sample material—RDX Type II Class 5—examined in the proficiency study for small-scale safety and thermal (SSST) testing of explosive materials for the Integrated Data Collection Analysis (IDCA) Program. The IDCA program is conducting proficiency testing on homemade explosives (HMEs). The reference sample materials are being studied to establish the accuracy of traditional explosives safety testing for each performing laboratory. These results will be used for comparison to results from testing HMEs. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The results of the study will add SSST testing results for a broad suite of different HMEs to the literature, potentially suggest new guidelines and methods for HME testing, and possibly establish what are the needed accuracies in SSST testing to develop safe handling practices. Described here are the results for impact, friction, electrostatic discharge, and scanning calorimetry analysis of a reference sample of RDX Type II Class 5. The results from each participating testing laboratory are compared using identical test material and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. These results are then compared to historical data from various sources. The performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Air Force Research Laboratory/ RXQL (AFRL), Indian Head Division, Naval Surface Warfare Center, (IHD-NSWC), and Sandia National Laboratories (SNL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when test protocols are not identical.

Natural radioactivity in soils of the state of Rio de Janeiro (Brazil): Radiological characterization and relationships to geological formation, soil types and soil properties.

Science.gov (United States)

Ribeiro, F C A; Silva, J I R; Lima, E S A; do Amaral Sobrinho, N M B; Perez, D V; Lauria, D C

2018-02-01

Located in the south-western part of Brazil, the state of Rio de Janeiro is geotectonically contained within a complex structural province that resulted in the amalgamation of the Western Gondwana Paleocontinent. To undertake an extensive radiological characterization of this complex geological province and investigate the influence of bedrock, soil type and soil chemical-physical characteristics on natural radionuclide levels in soils, 259 surface soil samples were collected that encompassed the main soil types and geological formations throughout the state. Gamma spectrometry analysis of the samples resulted in median values of 114 Bq.kg -1 for 40 K, 32 Bq.kg -1 for 226 Ra and 74 Bq.kg -1 for 228 Ra. The median value for 226 Ra was similar to the world median value for soils, the 40 K value was well below the worldwide value, and that for 228 Ra exceeded the world median value. The intense weathering caused by the high rainfall rates and high temperatures may be responsible for the low levels of 40 K in the soils, of which the strongly acidic and clayey soils are markedly K-depleted. A soil from a high-grade metamorphic rock (granulite) presented the lowest 226 Ra (18 Bq.kg -1 ) content, whereas the highest levels for 226 Ra (92 Bq.kg -1 ) and 228 Ra (139 Bq.kg - 1) were observed in a young soil enriched in primary minerals (Leptsol). A lowland soil (Gleysol) showed the highest median of 40 K (301 Bq.kg -1 ). Strongly acidic soils tended to present high amounts of 226 Ra, and sandy soils tended to contain low levels of 228 Ra. The external radiation dose indicates that the state has a background radiation level within the natural range. Copyright © 2017 Elsevier Ltd. All rights reserved.

Profile and bioconcentration of minerals by King Bolete (Boletus edulis) from the Płocka Dale in Poland.

Science.gov (United States)

Frankowska, Aneta; Ziółkowska, Joanna; Bielawski, Leszek; Falandysz, Jerzy

2010-01-01

This study aimed to provide basic data on the composition of metallic elements, including toxicologically important Cd and Hg, in popular and prized wild King Bolete mushrooms. We investigated the importance of soil substratum as a source of these metals. ICP-OES and CV-AAS were applied to determine the profile of Al, Ba, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, Sr and Zn in caps and stipes of King Bolete mushroom and in the surface layer of soil (0-10 cm) from the Płocka Dale area of Poland. Hg, Cu, Cd, Zn, Mg and K exhibited bioconcentration factors (BCF) > 1. Specifically, Hg, Cu and Cd (mean BCFs for caps were 110, 19 and 16, respectively) were efficiently bioconcentrated by King Bolete, while other elements were bioexcluded (BCF < 1). Cadmium was present in the caps at mean levels of 5.5 ± 2.4 mg kg(-1) dry weight (dw) and mercury at levels of 4.9 ± 1.4 mg kg(-1) dw, both occurring at elevated concentrations in those King Bolete mushrooms surveyed.

Community-specific hydraulic conductance potential of soil water decomposed for two Alpine grasslands by small-scale lysimetry

Science.gov (United States)

Frenck, Georg; Leitinger, Georg; Obojes, Nikolaus; Hofmann, Magdalena; Newesely, Christian; Deutschmann, Mario; Tappeiner, Ulrike; Tasser, Erich

2018-02-01

For central Europe in addition to rising temperatures an increasing variability in precipitation is predicted. This will increase the probability of drought periods in the Alps, where water supply has been sufficient in most areas so far. For Alpine grasslands, community-specific imprints on drought responses are poorly analyzed so far due to the sufficient natural water supply. In a replicated mesocosm experiment we compared evapotranspiration (ET) and biomass productivity of two differently drought-adapted Alpine grassland communities during two artificial drought periods divided by extreme precipitation events using high-precision small lysimeters. The drought-adapted vegetation type showed a high potential to utilize even scarce water resources. This is combined with a low potential to translate atmospheric deficits into higher water conductance and a lower biomass production as those measured for the non-drought-adapted type. The non-drought-adapted type, in contrast, showed high water conductance potential and a strong increase in ET rates when environmental conditions became less constraining. With high rates even at dry conditions, this community appears not to be optimized to save water and might experience drought effects earlier and probably more strongly. As a result, the water use efficiency of the drought-adapted plant community is with 2.6 gDW kg-1 of water much higher than that of the non-drought-adapted plant community (0.16 gDW kg-1). In summary, the vegetation's reaction to two covarying gradients of potential evapotranspiration and soil water content revealed a clear difference in vegetation development and between water-saving and water-spending strategies regarding evapotranspiration.

Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

International Nuclear Information System (INIS)

Baudin, G; Roudot, M; Genetier, M; Mateille, P; Lefrançois, A

2014-01-01

HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.

Shock-to-detonation transition of RDX, HMX and NTO based composite high explosives: experiments and modelling

Science.gov (United States)

Baudin, G.; Roudot, M.; Genetier, M.; Mateille, P.; Lefrançois, A.

2014-05-01

HMX, RDX and NTO based cast-cured plastic bounded explosive (PBX) are widely used in insensitive ammunitions. Designing modern warheads needs robust and reliable models to compute shock ignition and detonation propagation inside PBX. Comparing to a pressed PBX, a cast-cured PBX is not porous and the hot-spots are mainly located at the grain-binder interface leading to a different burning behavior during shock-to-detonation transition. Here, we review the shock-to-detonation transition (SDT) and its modeling for cast-cured PBX containing HMX, RDX and NTO. Future direction is given in conclusion.

Pharmacokinetics and Safety of DW1029M, a Botanical Drug for the Treatment of Diabetic Nephropathy, Following Single Doses in Healthy Subjects.

Science.gov (United States)

Kim, Yunjeong; Jeon, Ji-Young; Kim, Eun-Young; Lim, Cheol-Hee; Jang, Hwan Bong; Kim, Min-Gul

2017-09-01

DW1029M is a botanical extract of Morus albalinne root bark and Puerariae radix that is used for the treatment of diabetic nephropathy. This study evaluated the safety and pharmacokinetics of DW1029M following its administration in healthy Korean subjects. We conducted a randomized, open-label, single-dose, crossover phase 1 clinical study. During each period, subjects received 300, 600, or 1200 mg oral doses of DW1029M. Plasma concentrations of puerarin, daidzin, and daidzein were analyzed using a liquid chromatography-tandem mass spectrometry. Six healthy male subjects completed the study. The maximum concentration of the drug in the plasma (C max ) and area under the plasma drug concentration-time curve to the last measurable concentration (AUC last ) for puerarin, daidzin, and daidzein were assessed after oral administration of DW1029M. No serious adverse events or clinically or statistically significant adverse events associated with any of the drug levels were observed. The results of the measurement of vital signs, electrocardiogram, laboratory tests, and physical examinations indicated that no clinically significant changes occurred during this study. The DW1029M tablet was safe and well tolerated over a single dose range of 300-1200 mg. This pharmacokinetic study of a botanical drug may aid in the development of DW1029M. © 2017, The American College of Clinical Pharmacology.

Revamping of entisol soil physical characteristics with compost treatment

Science.gov (United States)

Sumono; Loka, S. P.; Nasution, D. L. S.

2018-02-01

Physical characteristic of Entisol soil is an important factor for the growth of plant. The aim of this research was to know the effect of compost application on physical characteristics of Entisol soil. The research method used was experimental method with 6 (six) treatments and 3 replications of which K1 = 10 kg Entisol soil without compost, K2 = 9 Kg Entisol soil with 1 kg compost, K3 = 8 kg Entisol soil with 2 kg compost, K4 = 7 kg Entisol soilwith3 kg compost, K5 = 6 kg Entisol soil with 4 kg compost and K6 = 5 kg Entisol soil with 5 kg compost. The observed parameters were soil texture, soil organic matter, soil thickness, porosity, soil pore size, soil permeability and water availability. The results showed that the Entisol soil texture was loamy sand texture, the value of soil organic matter ranged from 0.74% to 4.69%, soil thickness ranged from 13.83 to 20.16 cm, porosity ranged from16% to 37%, soil pore size ranged from 2.859 to 5.493 µm, permeability ranged from 1.24 to 5.64 cm/hour and water availability ranged from 6.67% to 9.12% by each treatment.

Development of an analytical methodology for the determination of the antiparasitic drug toltrazuril and its two metabolites in surface water, soil and animal manure

DEFF Research Database (Denmark)

Olsen, Jesper; Björklund, Erland; Krogh, Kristine A

2012-01-01

This paper presents the development, optimization and validation of a LC-MS/MS methodology to determine the antiparasitic veterinary drug toltrazuril and its two main metabolites, toltrazuril sulfoxide and toltrazuril sulfone, in environmental surface water, soil and animal manure. Using solid...... phase extraction and selective pressurized liquid extraction with integrated clean-up, the analytical method allows for the determination of these compounds down to 0.06-0.13 ng L(-1) in water, 0.01-0.03 ng g(-1)dw in soil and 0.22-0.51 ng g(-1) dw in manure. The deuterated analog of toltrazuril...... was used as internal standard, and ensured method accuracy in the range 96-123% for water and 77-110% for soil samples. The developed method can also be applied to simultaneously determine steroid hormones in the solid samples. The antiparasitic drug and its metabolites were found in manure and soil up...

Towards practical cadmium phytoextraction with Noccaea caerulescens.

Science.gov (United States)

Simmons, R W; Chaney, R L; Angle, J S; Kruatrachue, M; Klinphoklap, S; Reeves, R D; Bellamy, P

2015-01-01

A series of field trials were conducted to investigate the potential of Noccaea caerulescens F.K. Mey [syn. Thlaspi caerulescens J &C Presl. (see Koch and Al-Shehbaz 2004)] populations (genotypes) derived from southern France to phytoextract localized Cd/Zn contamination in Thailand. Soil treatments included pH variation and fertilization level and application of fungicide. N. caerulescens populations were transplanted to the field plots three months after germination and harvested in May, prior to the onset of seasonal rains. During this period growth was rapid with shoot biomass ranging from 0.93-2.2 g plant(-1) (280-650 kg ha(-1)) DW. Shoot Cd and Zn concentrations for the four populations evaluated ranged from 460-600 and 2600-2900 mg kg(-1) DW respectively. Cadmium and Zn Translocation Factors (shoot/root) for the populations tested ranged from 0.91-1.0 and 1.7-2.1 and Bioaccumulation Factors ranged from 12-15 and 1.2-1.3. We conclude that optimizing the use of fungicidal sprays, acidic soil pH, planting density and increasing the effective cropping period will increase rates of Cd and Zn removal enough to facilitate practical Cd phytoextraction from rice paddy soils in Thailand.

Biochar from sugarcane filtercake reduces soil CO2 emissions relative to raw residue and improves water retention and nutrient availability in a highly-weathered tropical soil.

Science.gov (United States)

Eykelbosh, Angela Joy; Johnson, Mark S; Santos de Queiroz, Edmar; Dalmagro, Higo José; Guimarães Couto, Eduardo

2014-01-01

In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing) on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w.) were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w.) raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w.) in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions.

Biochar from Sugarcane Filtercake Reduces Soil CO2 Emissions Relative to Raw Residue and Improves Water Retention and Nutrient Availability in a Highly-Weathered Tropical Soil

Science.gov (United States)

Eykelbosh, Angela Joy; Johnson, Mark S.; Santos de Queiroz, Edmar; Dalmagro, Higo José; Guimarães Couto, Eduardo

2014-01-01

In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing) on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w.) were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w.) raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w.) in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions. PMID:24897522

Biochar from sugarcane filtercake reduces soil CO2 emissions relative to raw residue and improves water retention and nutrient availability in a highly-weathered tropical soil.

Directory of Open Access Journals (Sweden)

Angela Joy Eykelbosh

Full Text Available In Brazil, the degradation of nutrient-poor Ferralsols limits productivity and drives agricultural expansion into pristine areas. However, returning agricultural residues to the soil in a stabilized form may offer opportunities for maintaining or improving soil quality, even under conditions that typically promote carbon loss. We examined the use of biochar made from filtercake (a byproduct of sugarcane processing on the physicochemical properties of a cultivated tropical soil. Filtercake was pyrolyzed at 575°C for 3 h yielding a biochar with increased surface area and porosity compared to the raw filtercake. Filtercake biochar was primarily composed of aromatic carbon, with some residual cellulose and hemicellulose. In a three-week laboratory incubation, CO2 effluxes from a highly weathered Ferralsol soil amended with 5% biochar (dry weight, d.w. were roughly four-fold higher than the soil-only control, but 23-fold lower than CO2 effluxes from soil amended with 5% (d.w. raw filtercake. We also applied vinasse, a carbon-rich liquid waste from bioethanol production typically utilized as a fertilizer on sugarcane soils, to filtercake- and biochar-amended soils. Total CO2 efflux from the biochar-amended soil in response to vinasse application was only 5% of the efflux when vinasse was applied to soil amended with raw filtercake. Furthermore, mixtures of 5 or 10% biochar (d.w. in this highly weathered tropical soil significantly increased water retention within the plant-available range and also improved nutrient availability. Accordingly, application of sugarcane filtercake as biochar, with or without vinasse application, may better satisfy soil management objectives than filtercake applied to soils in its raw form, and may help to build soil carbon stocks in sugarcane-cultivating regions.

Involvement of an antioxidant defense system in the adaptive response to cadmium in maize seedlings (Zea mays L.).

Science.gov (United States)

Xu, Xianghua; Liu, Cuiying; Zhao, Xiaoyan; Li, Renying; Deng, Wenjing

2014-11-01

Chemical and biological analyses were used to investigate the growth response and antioxidant defense mechanism of maize seedlings (Zea mays L.) grown in soils with 0-100 mg kg(-1) Cd. Results showed that maize seedlings have strong abilities to accumulate and tolerate high concentrations of Cd. For soil with 50 mg kg(-1) Cd, the Cd contents in roots and shoots of maize seedlings are as large as 295.6 and 153.0 mg kg(-1) DW, respectively, without visible symptoms of toxicity. Lower soil Cd concentrations lead to a decrease in reduced glutathione (GSH) content in leaves of maize seedlings, whereas higher soil Cd concentrations resulted in an increase in the activities of superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Maize seedlings have strong capacities to adapt to low concentrations of Cd by consuming GSH and to develop an antioxidative enzyme system to defend against high-Cd stress.

Frictional properties of single crystals HMX, RDX and PETN explosives

International Nuclear Information System (INIS)

Wu, Y.Q.; Huang, F.L.

2010-01-01

The frictional properties of single crystals of cyclotetramethylene tetranitramine (HMX), cyclotrimethylene trinitramine (RDX) and pentaerythritol tetranitrate (PETN) secondary explosives are examined using a sensitive friction machine. The explosive crystals used for the measurements are at least 3.5 mm wide. The friction coefficients between crystals of the same explosive (i.e., HMX on HMX, etc.), crystals of different explosives (i.e., HMX on RDX, etc.), and each explosive and a well-polished gauge steel surface are determined. The frictional surfaces are also studied under an environmental scanning electron microscope (ESEM) to analyze surface microstructural changes under increasing loading forces. The friction coefficients vary considerably with increasing normal loading forces and are particularly sensitive to slider shapes, crystal roughness and the mechanical properties of both the slider and the sample. With increasing loading forces, most friction experiments show surface damage, consisting of grooves, debris, and nano-particles, on both the slider and sample. In some cases, a strong evidence of a localized molten state is found in the central region of the friction track. Possible mechanisms that affect the friction coefficient are discussed based on microscopic observations.

Can we predict uranium bioavailability based on soil parameters? Part 1: effect of soil parameters on soil solution uranium concentration.

Science.gov (United States)

Vandenhove, H; Van Hees, M; Wouters, K; Wannijn, J

2007-01-01

Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for (238)U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K(d), L kg(-1)) and the organic matter content (R(2)=0.70) and amorphous Fe content (R(2)=0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH=6, log(K(d)) was linearly related with pH [log(K(d))=-1.18 pH+10.8, R(2)=0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex.

Decontamination of a polychlorinated biphenyls-contaminated soil by phytoremediation-assisted bioaugmentation.

Science.gov (United States)

Secher, C; Lollier, M; Jézéquel, K; Cornu, J Y; Amalric, L; Lebeau, T

2013-07-01

A 70 day pot experiment was conducted for the cleaning-up of a PCBs-contaminated soil (104 mg kg(-1) soil DW) using bioaugmentation with Burkholderia xenovorans LB400 (LB400) assisted or not by the use of tall fescue (Festuca arundinacea). The total cultivable bacteria of the soil were higher with the presence of plants. Real-time PCR showed that LB400 (targeting 16S-23S rRNA ITS) survived with abundance related to total bacteria (targeting 16S rRNA) being higher with fescue (up to a factor of three). Bioaugmentation had a positive effect on fescue biomass and more specifically on roots (by a factor of three). PCB dissipation (sum of congeners 28, 52, 101, 118, 153, 180) averaged 13 % (bioaugmented-planted) up to 32 % (non bioaugmented-planted), without any significant difference between treatments. Basically our results demonstrated that indigenous bacteria were able to dissipate PCBs (26.2 % dissipation). PCB dissipation was not related to the abundance of LB400 or to the total bacterial counts. Bioaugmentation or fescue altered the structure of the bacterial community of the soil, not the combination of both. Principal component analysis showed that bioaugmentation tended to improve the control of the process (lower variability in PCB dissipation). Opposite to that bioaugmentation increased the variability of the structure of the bacterial community.

Electron shuttle-mediated biotransformation of hexahydro-1,3,5-trinitro-1,3,5-triazine adsorbed to granular activated carbon.

Science.gov (United States)

Millerick, Kayleigh; Drew, Scott R; Finneran, Kevin T

2013-08-06

Granular activated carbon (GAC) effectively removes hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) from groundwater but generates RDX-laden GAC that must be disposed of or regenerated. Batch reactors containing GAC to which RDX was preadsorbed were used in experiments to test the potential for adsorbed RDX reduction and daughter product formation using (i) chemically reduced anthrahydroquinone-2,6-disulfonate (AH2QDS), (ii) resting Geobacter metallireducens strain GS-15, and (iii) a combined system containing AQDS and GS-15. Approximately 97.0% of the adsorbed RDX was transformed in each of these experimental systems by 90 h. Chemically reduced AQDS (AH2QDS) transformed 99.2% of adsorbed RDX; formaldehyde was produced rapidly and was stoichiometric (3 mol HCHO per mol RDX). Geobacter metallireducens also reduced RDX with and without AQDS present. This is the first study to demonstrate biological transformation of RDX adsorbed to GAC. Formaldehyde increased and then decreased in biological systems, suggesting a previously unreported capacity for G. metallireducens to oxidize formaldehyde, which was confirmed with resting cell suspensions. These data suggest the masses of GAC waste currently produced by activated carbon at RDX remediation sites can be minimized, decreasing the carbon footprint of the treatment technology. Alternatively, this strategy may be used to develop a Bio-GAC system for ex situ RDX treatment.

Response of plants to high concentrations of uranium stress and the screening of remediation plants

International Nuclear Information System (INIS)

Tang Yongjin; Luo Xuegang; Zeng Feng; Jiang Shijie

2013-01-01

Studies of the resistance and accumulation ability of different plant species to uranium (U) has important influence on the bioremediation of U contaminated soil. The resistance and enrichment ability of high concentrations of U (500 mg · kg"-"1 soil) in fourteen plant species were investigated and evaluated in this study in order to screen remediation plants for governance soil U contamination. The results showed that: (1) high concentrations of U stress had different effects on the emergence and survival of the different plants. The seed emergence of Hibiscus esculentus was reduced by 2/3, but the seed emergence of Gynura cusimbua (D. Don) S. Moore, Chenopodium album L. and Phaseolus vulgaris var. humilis Alef were not reduced. Under the contaminated soil, all the sesamum indicum died within a month after the emergence and the survival number of Amaranth and Iresine herbstii 'Aureo-reticulata' reduced by about 80%. But the survival number of Alternanthera philoxeroides (Mart.) Griseb., Chenopodium album L. and Phaseolus vulgaris var. humilis Alef were not influenced. (2) The biomass of the plants would be reduced by 8-99% in the uranium-contaminated soil. The anti-stress ability of Phaseolus vulgaris var. humilis Alef was the strongest in the fourteen plants, and Cucurbita pepo L., Sorghumbicolor (L.) Moench, Ipomoea aquatica Forsk, Helianthus annuus, Chenopodium album L. and Alternanthera philoxeroides (Mart.) Griseb. showed some the anti-stress ability. (3) Significant differences were found in the capacity of plants to absorb uranium between under high-uranium contaminated soil and under the non-uranium contaminated soil were. The plants with higher uranium content in thenon-contaminated soil were Gomphrena globosa, and Cucurbita pepo L., which were 2.249 mg · kg"-"1 DW and 1.620 mg · kg"-"1 DW, respectively. But the plants with higher uranium content in the high uranium contaminated soil were Cichorium intybus L., Amaranth and Ipomoea aquatica Forsk, which

Can we predict uranium bioavailability based on soil parameters? Part 1: Effect of soil parameters on soil solution uranium concentration

International Nuclear Information System (INIS)

Vandenhove, H.; Hees, M. van; Wouters, K.; Wannijn, J.

2007-01-01

Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for 238 U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K d , L kg -1 ) and the organic matter content (R 2 = 0.70) and amorphous Fe content (R 2 = 0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH = 6, log(K d ) was linearly related with pH [log(K d ) = - 1.18 pH + 10.8, R 2 = 0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex. - Uranium solubility in soil can be predicted from organic matter or amorphous iron content and pH or with complex multilinear models considering several soil parameters

Mapping of A1 conferring resistance to the aphid Amphorophora idaei and dw (dwarfing habit in red raspberry (Rubus idaeus L. using AFLP and microsatellite markers

Directory of Open Access Journals (Sweden)

Knight Victoria H

2007-03-01

Full Text Available Abstract Background Raspberry breeding programmes worldwide aim to produce improved cultivars to satisfy market demands and within these programmes there are many targets, including increased fruit quality, yield and season, and improved pest and disease resistance and plant habit. The large raspberry aphid, Amphorophora idaei, transmits four viruses and vector resistance is an objective in raspberry breeding. The development of molecular tools that discriminate between aphid resistance genes from different sources will allow the pyramiding of such genes and the development of raspberry varieties with superior pest resistance. We have raised a red raspberry (Rubus idaeus F1 progeny from the cross 'Malling Jewel' × 'Malling Orion' (MJ × MO, which segregates for resistance to biotype 1 of the aphid Amphorophora idaei and for a second phenotypic trait, dwarf habit. These traits are controlled by single genes, denoted (A1 and (dw respectively. Results The progeny of 94 seedlings was scored for the segregation of 95 AFLP and 22 SSR markers and a linkage map was constructed that covers a total genetic distance of 505 cM over seven linkage groups. The average linkage group length was 72.2 cM and there was an average of 17 markers per linkage group, of which at least two were codominant SSRs, allowing comparisons with previously published maps of raspberry. The two phenotypic traits, A1 and dw, mapped to linkage groups 3 and 6 respectively. Conclusion The mapping of A1 will facilitate the discrimination of resistance genes from different sources and the pyramiding of aphid resistance genes in new raspberry cultivars; the mapping of dw will allow further investigations into the genetics of dwarfing habit in Rubus.

Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette.

Science.gov (United States)

Beulig, Felix; Heuer, Verena B; Akob, Denise M; Viehweger, Bernhard; Elvert, Marcus; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

2015-03-01

Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (ΔpH ∼0.8), strongly enriched in organic carbon (up to 10 times), and exhibited lower prokaryotic diversity. It was dominated by methanogens and subdivision 1 Acidobacteria, which likely thrived under stable hypoxia and acidic pH. Anoxic incubations revealed enhanced formation of acetate and methane (CH4) from hydrogen (H2) and CO2 consistent with elevated CH4 and acetate levels in the mofette soil. (13)CO2 mofette soil incubations showed high label incorporations with ∼512 ng (13)C g (dry weight (dw)) soil(-1) d(-1) into the bulk soil and up to 10.7 ng (13)C g (dw) soil(-1) d(-1) into almost all analyzed bacterial lipids. Incorporation of CO2-derived carbon into archaeal lipids was much lower and restricted to the first 10 cm of the soil. DNA-SIP analysis revealed that acidophilic methanogens affiliated with Methanoregulaceae and hitherto unknown acetogens appeared to be involved in the chemolithoautotrophic utilization of (13)CO2. Subdivision 1 Acidobacteriaceae assimilated (13)CO2 likely via anaplerotic reactions because Acidobacteriaceae are not known to harbor enzymatic pathways for autotrophic CO2 assimilation. We conclude that CO2-induced geochemical changes promoted anaerobic and acidophilic organisms and altered carbon turnover in affected soils.

Copper removal from contaminated soils by soil washing process using camellian-derived saponin

Science.gov (United States)

Reyes, Arturo; Fernanda Campos, Maria; Videla, Álvaro; Letelier, María Victoria; Fuentes, Bárbara

2015-04-01

Antofagasta Region in North of Chile has been the main copper producer district in the world. As a consequence of a lack of mining closure regulation, a large number of abandon small-to-medium size metal-contaminated sites have been identified in the last survey performed by the Chilean Government. Therefore, more research development on sustainable reclamation technologies must be made in this extreme arid-dry zone. The objective of this study is to test the effectiveness of soil remediation by washing contaminated soil using camellian-derived saponin for the mobilization of copper. Soil samples were taken from an abandoned copper mine site located at 30 km North Antofagasta city. They were dried and sieved at 75 µm for physico-chemical characterization. A commercial saponin extracted from camellias seed was used as biosurfactant. The soil used contains 67.4 % sand, 26.3 % silt and 6.3 % clay. The soil is highly saline (electric conductivity, 61 mScm-1), with low organic matter content (0.41%), with pH 7.30, and a high copper concentration (2200 mg Kg-1 soil). According to the sequential extraction procedure of the whole soil, copper species are mainly as exchangeable fraction (608.2 mg Kg-1 soil) and reducible fraction (787.3 mg Kg-1 soil), whereas the oxidizable and residual fractions are around 205.7 and 598.8 mg Kg-1 soil, respectively. Soil particles under 75 µm contain higher copper concentrations (1242 mg Kg-1 soil) than the particle fraction over 75 µm (912 mg Kg-1 soil). All washing assays were conducted in triplicate using a standard batch technique with and without pH adjustment. The testing protocols includes evaluation of four solid to liquid ratio (0.5:50; 1.0:50; 2.0:50, and 5.0:50) and three saponin concentrations (0, 1, and 4 mg L-1). After shaking (24 h, 20±1 °C) and subsequently filtration (0.45 µm), the supernatants were analyzed for copper and pH. The removal efficiencies of copper by saponin solutions were calculated in according to the

[Soil basal respiration and enzyme activities in the root-layer soil of tea bushes in a red soil].

Science.gov (United States)

Yu, Shen; He, Zhenli; Zhang, Rongguang; Chen, Guochao; Huang, Changyong

2003-02-01

Soil basal respiration potential, metabolic quotient (qCO2), and activities of urease, invertase and acid phosphomonoesterase were investigated in the root-layer of 10-, 40-, and 90-yr-old tea bushes grown on the same type of red soil. The soil daily basal respiration potential ranged from 36.23 to 58.52 mg.kg-1.d-1, and the potentials in the root-layer of 40- or 90-yr-old were greater than that of 10-yr old tea bushes. The daily qCO2, ranging from 0.30 to 0.68, was in the reverse trend. The activities of test three enzymes changed differently with tea bushes' age. Urease activity in the root-layer of all age tea bushes ranged from 41.48 to 47.72 mg.kg-1.h-1 and slightly decreased with tea bushes' age. Invertase activity was 189.29-363.40 mg.kg-1.h-1 and decreased with tea bushes' age, but its activity in the root-layer of 10-year old tea bushes was significantly greater than that in the root-layer soil of 40- or 90-year old tea bushes. Acid phosphomonoesterase activity (444.22-828.32 mg.kg-1.h-1) increased significantly with tea bushes' age. Soil basal respiration potential, qCO2 and activities of 3 soil enzymes were closely related to soil pH, soil organic carbon, total nitrogen and C/N ratio, total soluble phenol, and microbial biomass carbon, respectively.

A theoretical study of the relaxation of a phenyl group chemisorbed to an RDX freestanding thin film

Energy Technology Data Exchange (ETDEWEB)

Pereverzev, Andrey, E-mail: pereverzeva@missouri.edu; Sewell, Thomas D., E-mail: sewellt@missouri.edu [Department of Chemistry, University of Missouri-Columbia, Columbia, Missouri 65211-7600 (United States)

2016-08-07

Energy relaxation from an excited phenyl group chemisorbed to the surface of a crystalline thin film of α-1,3,5-trinitro-1,3,5-triazacyclohexane (α-RDX) at 298 K and 1 atm is simulated using molecular dynamics. Two schemes are used to excite the phenyl group. In the first scheme, the excitation energy is added instantaneously as kinetic energy by rescaling momenta of the 11 atoms in the phenyl group. In the second scheme, the phenyl group is equilibrated at a higher temperature in the presence of static RDX geometries representative of the 298 K thin film. An analytical model based on ballistic phonon transport that requires only the harmonic part of the total Hamiltonian and includes no adjustable parameters is shown to predict, essentially quantitatively, the short-time dynamics of the kinetic energy relaxation (∼200 fs). The dynamics of the phenyl group for times longer than about 6 ps follows exponential decay and agrees qualitatively with the dynamics described by a master equation. Long-time heat propagation within the bulk of the crystal film is consistent with the heat equation.

Bioaccumulation and physiological effects of excess lead in a roadside pioneer species Sonchus oleraceus L.

Science.gov (United States)

Xiong, Z T

1997-01-01

Seedlings of Sonchus oleraceus L. were transplanted to soil supplied with lead acetate at dosages of 0, 800, 1600 and 3200 mg kg(-1) DW. Measures of chlorophyll content, peroxidase (POD) activity, shoot length, biomass and Pb content in the plant tissues were obtained from the experimental plants. With increasing amounts of Pb in the soil, the chlorophyll content, shoot length and biomass decreased, while POD activity and Pb content in the plant tissues increased. At 3200 mg kg(-1) Pb treatment, Pb content in the plant leaf, stem and root were 65.67, 149.82 and 1113.24 mg kg(-1), respectively. Only at 3200 mg kg(-1) Pb treatment did chlorophyll content, shoot length and biomass significantly increase by 18, 15 and 44%, respectively, while POD decreased by 39% over the control. The potential of applying this species in phytoremediation of Pb contaminated roadside soils and thus restoration of the roadside vegetation are discussed.

Laboratory Demonstration of Abiotic Technologies for Removal of RDX from a Process Waste Stream

Science.gov (United States)

2010-06-01

calcium carbonate CSTR continuous stirred tank reactor d day DoD Department of Defense gal gallons gpd gallons per day RDX hexahydro-1,3,5... CSTR ), and (c) Plug flow reactor. a batch reactor may be used if the desired reaction occurs while the reactor volume is inconstant (i.e., during the...products from the reactor system. Con- tinuous flow reactors may be further divided into continuous stirred tank reactors ( CSTRs ) and plug or pipe flow

Diffusion-weighted (DW) MRI in lung cancers. ADC test-retest repeatability

Energy Technology Data Exchange (ETDEWEB)

Weller, Alex; Papoutsaki, Marianthi Vasiliki; Blackledge, Matthew; DeSouza, Nandita M. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK Cancer Imaging Centre, Surrey (United Kingdom); Waterton, John C. [University of Manchester, Manchester (United Kingdom); Chiti, Arturo [Humanitas University, Milan (Italy); Stroobants, Sigrid [Universiteit Antwerpen, Antwerpen (Belgium); Kuijer, Joost [Vrije Universiteit Medisch Centrum, Amsterdam (Netherlands); Morgan, Veronica [Royal Marsden NHS Foundation Trust, Department of Medicine, London (United Kingdom)

2017-11-15

To determine the test-retest repeatability of Apparent Diffusion Coefficient (ADC) measurements across institutions and MRI vendors, plus investigate the effect of post-processing methodology on measurement precision. Thirty malignant lung lesions >2 cm in size (23 patients) were scanned on two occasions, using echo-planar-Diffusion-Weighted (DW)-MRI to derive whole-tumour ADC (b = 100, 500 and 800 s/mm{sup -2}). Scanning was performed at 4 institutions (3 MRI vendors). Whole-tumour volumes-of-interest were copied from first visit onto second visit images and from one post-processing platform to an open-source platform, to assess ADC repeatability and cross-platform reproducibility. Whole-tumour ADC values ranged from 0.66-1.94x10{sup -3} mm{sup 2}s{sup -1} (mean = 1.14). Within-patient coefficient-of-variation (wCV) was 7.1% (95% CI 5.7-9.6%), limits-of-agreement (LoA) -18.0 to 21.9%. Lesions >3 cm had improved repeatability: wCV 3.9% (95% CI 2.9-5.9%); and LoA -10.2 to 11.4%. Variability for lesions <3 cm was 2.46 times higher. ADC reproducibility across different post-processing platforms was excellent: Pearson's R{sup 2} = 0.99; CoV 2.8% (95% CI 2.3-3.4%); and LoA -7.4 to 8.0%. A free-breathing DW-MRI protocol for imaging malignant lung tumours achieved satisfactory within-patient repeatability and was robust to changes in post-processing software, justifying its use in multi-centre trials. For response evaluation in individual patients, a change in ADC >21.9% will reflect treatment-related change. (orig.)

Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne

International Nuclear Information System (INIS)

Rocheleau, Sylvie; Lachance, Bernard; Kuperman, Roman G.; Hawari, Jalal; Thiboutot, Sonia; Ampleman, Guy; Sunahara, Geoffrey I.

2008-01-01

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. - Cyclic nitramine explosives accumulate in perennial ryegrass and exhibit distinct uptake patterns

Toxicity and uptake of cyclic nitramine explosives in ryegrass Lolium perenne

Energy Technology Data Exchange (ETDEWEB)

Rocheleau, Sylvie; Lachance, Bernard [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Kuperman, Roman G. [Edgewood Chemical Biological Center, 5183 Blackhawk Road, Aberdeen Proving Ground, MD 21010-5424 (United States); Hawari, Jalal [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada); Thiboutot, Sonia; Ampleman, Guy [Defense Research and Development Canada, 2459 Pie IX Boulevard, Val Belair, Quebec G3J 1X5 (Canada); Sunahara, Geoffrey I. [Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, Quebec H4P 2R2 (Canada)], E-mail: geoffrey.sunahara@cnrc-nrc.gc.ca

2008-11-15

Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) are cyclic nitramines used as explosives. Their ecotoxicities have been characterized incompletely and little is known about their accumulation potential in soil organisms. We assessed the toxicity and uptake of these explosives in perennial ryegrass Lolium perenne L. exposed in a Sassafras sandy loam (SSL) or in a sandy soil (DRDC, CL-20 only) containing contrasting clay contents (11% and 0.3%, respectively). A 21-d exposure to RDX, HMX or CL-20 in either soil had no adverse effects on ryegrass growth. RDX and HMX were translocated to ryegrass shoots, with bioconcentration factors (BCF) of up to 15 and 11, respectively. In contrast, CL-20 was taken up by the roots (BCF up to 19) with no translocation to the shoots. These studies showed that RDX, HMX, and CL-20 can accumulate in plants and may potentially pose a risk of biomagnification across the food chain. - Cyclic nitramine explosives accumulate in perennial ryegrass and exhibit distinct uptake patterns.

Radionuclides in sheep grazing near old uranium mines

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Fernando P.; Oliveira, Joao M.; Malta, M. [Instituto Superior Tecnico/Campus Tecnologico e Nuclear/ (IST/CTN), Universidade de Lisboa, Estrada Nacional 10 - ao km 139,7, - 2695-066 Bobadela LRS (Portugal); Lemos, M.E. [Servicos de Alimentacao e Veterinaria da Regiao Centro, Bairro Na Sra dos Remedios, 6300 Guarda (Portugal); Vala, H.; Esteves, F. [Escola Superior Agraria de Viseu, Quinta da Alagoa, Estrada de Nelas, Ranhados,3500-606 Viseu (Portugal)

2014-07-01

During the past century extensive uranium mining took place in Portugal for radium and uranium production. Many uranium deposits were mined as open pits and after ore extraction and transportation to milling facilities, mining wastes were left on site. One uranium ore mining site, Boco Mine, was extracted in the 1960's and 70's and mining waste and open pits were left uncovered and non-remediated since closure of uranium mining activities. During the nineties a quarry for sand extraction was operated in the same site and water from a local stream was extensively used in sand sieving. Downstream the mine areas, agriculture soils along the water course are currently used for cattle grazing. Water from this stream, and water wells, soil, pasture and sheep meat were analyzed for radionuclides of the uranium series. The U- series radionuclide {sup 226}Ra was generally the highest in concentrations especially in soil, pasture, and in internal organs of sheep. Ra-226 concentrations averaged 1093±96 Bq/kg (dry weight) in soil, 43±3 Bq/kg (dw) in pasture, and 0.76±0.41 Bq/kg (dw) in muscle tissue of sheep grown there. Other sheep internal organs displayed much higher {sup 226}Ra concentrations, such as the brain and kidneys with 7.7±2.3 Bq/kg (dw) and 28±29 Bq/kg (dw), respectively. Results of tissue sample analysis for sheep grown in a comparison area were 2 to 11 times lower, depending on the tissue. Absorbed radiation doses for internal organs of sheep were computed and may exceed 20 mSv/y in the kidney. Although elevated, this absorbed radiation dose still is below the threshold for biological effects on mammals. Nevertheless, enhanced environmental radioactive contamination mainly due to radium was observed in the area of influence of this legacy uranium mine and there is potential food chain transfer for humans (authors)

Transformation products of 1,1-dimethylhydrazine and their distribution in soils of fall places of rocket carriers in Central Kazakhstan

International Nuclear Information System (INIS)

Kenessov, Bulat; Alimzhanova, Mereke; Sailaukhanuly, Yerbolat; Baimatova, Nassiba; Abilev, Madi; Batyrbekova, Svetlana; Carlsen, Lars; Tulegenov, Akyl; Nauryzbayev, Mikhail

2012-01-01

In our research, three fall places of first stages of Proton rockets have been studied for the presence and distribution of transformation products of 1,1-dimethylhydrazine (1,1-DMH). Results of identification of transformation products of 1,1-DMH in real soil samples polluted due to rocket fuel spills allowed to detect 18 earlier unknown metabolites of 1,1-DMH being formed only under field conditions. According to the results of quantitative analyses, maximum concentrations of 1-methyl-1H-1,2,4-triazole made up 57.3, 44.9 and 13.3 mg kg −1 , of 1-ethyl-1H-1,2,4-triazole — 5.45, 3.66 and 0.66 mg kg −1 , of 1,3-dimethyl-1H-1,2,4-triazole - 24.0, 17.8 and 4.9 mg kg −1 in fall places 1, 2 and 3, respectively. 4-Methyl-4H-1,2,4-triazole was detected only in fall places 2 and 3 where its maximum concentrations made up 4.2 and 0.66 mg kg −1 , respectively. The pollution of soils with transformation products of 1,1-DMH was only detected in epicenters of fall places having a diameter of 8 to10 m where rocket boosters landed. The results of a detailed study of distribution of 1,1-DMH transformation products along the soil profile indicate that transformation products can migrate down to the depth of 120 cm, The highest concentrations of 1,1-DMH transformation products were detected, as a rule, at the depth 20 to 60 cm. However, this index can vary depending on the compound, humidity and physical properties of soil, landscape features and other conditions. In the surface layer, as a rule, only semi-volatile products of transformation were detected which was caused by fast evaporation and biodegradation of volatile metabolites. - Highlights: ► We study metabolites of 1,1-dimethylhydrazine and their distribution in soils. ► Fifty four metabolites can be formed in soils polluted with 1,1-dimethylhydrazine. ► Metabolites are detected in the epicenter having diameter of about 10 m. ► Metabolites can migrate down to the depth of 120 cm. ► Volatile metabolites

Transformation products of 1,1-dimethylhydrazine and their distribution in soils of fall places of rocket carriers in Central Kazakhstan

Energy Technology Data Exchange (ETDEWEB)

Kenessov, Bulat, E-mail: bkenesov@gmail.com [Center of Physical Chemical Methods of Research and Analysis, al-Farabi Kazakh National University, 96A Tole Bi st., Almaty, 050012 (Kazakhstan); Alimzhanova, Mereke; Sailaukhanuly, Yerbolat; Baimatova, Nassiba; Abilev, Madi; Batyrbekova, Svetlana [Center of Physical Chemical Methods of Research and Analysis, al-Farabi Kazakh National University, 96A Tole Bi st., Almaty, 050012 (Kazakhstan); Carlsen, Lars [Awareness Center, Linkopingvej 35, Trekroner, DK-4000 Roskilde (Denmark); Department of Chemical Engineering, Kazakh-British Technical University, 59 Tole Bi st., Almaty, 050000 (Kazakhstan); Tulegenov, Akyl; Nauryzbayev, Mikhail [Center of Physical Chemical Methods of Research and Analysis, al-Farabi Kazakh National University, 96A Tole Bi st., Almaty, 050012 (Kazakhstan)

2012-06-15

In our research, three fall places of first stages of Proton rockets have been studied for the presence and distribution of transformation products of 1,1-dimethylhydrazine (1,1-DMH). Results of identification of transformation products of 1,1-DMH in real soil samples polluted due to rocket fuel spills allowed to detect 18 earlier unknown metabolites of 1,1-DMH being formed only under field conditions. According to the results of quantitative analyses, maximum concentrations of 1-methyl-1H-1,2,4-triazole made up 57.3, 44.9 and 13.3 mg kg{sup -1}, of 1-ethyl-1H-1,2,4-triazole - 5.45, 3.66 and 0.66 mg kg{sup -1}, of 1,3-dimethyl-1H-1,2,4-triazole - 24.0, 17.8 and 4.9 mg kg{sup -1} in fall places 1, 2 and 3, respectively. 4-Methyl-4H-1,2,4-triazole was detected only in fall places 2 and 3 where its maximum concentrations made up 4.2 and 0.66 mg kg{sup -1}, respectively. The pollution of soils with transformation products of 1,1-DMH was only detected in epicenters of fall places having a diameter of 8 to10 m where rocket boosters landed. The results of a detailed study of distribution of 1,1-DMH transformation products along the soil profile indicate that transformation products can migrate down to the depth of 120 cm, The highest concentrations of 1,1-DMH transformation products were detected, as a rule, at the depth 20 to 60 cm. However, this index can vary depending on the compound, humidity and physical properties of soil, landscape features and other conditions. In the surface layer, as a rule, only semi-volatile products of transformation were detected which was caused by fast evaporation and biodegradation of volatile metabolites. - Highlights: Black-Right-Pointing-Pointer We study metabolites of 1,1-dimethylhydrazine and their distribution in soils. Black-Right-Pointing-Pointer Fifty four metabolites can be formed in soils polluted with 1,1-dimethylhydrazine. Black-Right-Pointing-Pointer Metabolites are detected in the epicenter having diameter of about 10 m

Levels and transfer of 210Po and 210Pb in Nordic terrestrial ecosystems

International Nuclear Information System (INIS)

Brown, J.E.; Gjelsvik, R.; Roos, P.; Kalas, J.A.; Outola, I.; Holm, E.

2011-01-01

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides 210 Po and 210 Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in 210 Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of 210 Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg -1 d.w. and in plants and lichens between 20 and 138 Bq kg -1 d.w. The results showed that soil humus is an important reservoir for 210 Po and 210 Pb and that fauna in close contact with this media may also exhibit elevated levels of 210 Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of 210 Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of 210 Po in this system.

Utilisation aspects of ashes and green liquor dregs from an integrated semichemical pulp and board mill

Energy Technology Data Exchange (ETDEWEB)

Manskinen, K.

2013-09-01

This thesis investigated the properties of bottom and fly ashes originating from a bubbling fluidised bed boiler (120 MW) using two different fuel mixtures (i.e. Fuel mixture A: coal, wood and peat; and B: wood and peat) and of the green liquor dregs originating from the associated semichemical pulp and board mill in relation to the potential utilisation of these residues from various aspects. The total concentrations of As, Cd, Cr, Cu, Ni, Pb, Zn and Hg in the bottom ashes were lower than the maximum allowable concentrations for these elements in forest fertilisers. The total Ca concentrations in bottom ashes A (2.4%; d.w.) and B (3.4%; d.w.) were lower than the legal requirement of 6.0% (d.w.) for ash used as a forest fertiliser. The total Ca concentrations in fly ashes A (6.4%; d.w.) and B (11.0%; d.w.) were higher than the minimum limit value of 6.0% (d.w.), but the concentration of As in fly ashes A (46.9 mg/kg d.w.) and B (41.3 mg/kg; d.w.) exceeded the maximum limit value of 40 mg/kg (d.w.). Only bottom ash B could be used as a forest fertiliser, provided some additional Ca is used. The bottom ashes both fulfilled the Finnish regulations on waste recovery in earth construction. Due to the elevated total concentration of PAH (23 mg/kg; d.w.) and extractable concentrations of Mo (3.9 mg/kg; d.w.) and Se (0.2 mg/kg; d.w.) in fly ash A, this residue cannot be used in covered structures. Due to the elevated concentration of PAH (90 mg/kg; d.w.) in fly ash B, this residue cannot be used in covered and paved structures. However, the utilisation of these residues as an earth construction agent is still possible, but an environmental permit would be required. According to the sequential extraction studies, extractable concentrations of most of the elements in the fly ash A were higher than those in the bottom ash A. The extractability of various elements, both in the bottom and fly ashes A, varied widely. Most of the elements did not occur as readily soluble and

Chemical and physical properties of cyclone fly ash from the grate-fired boiler incinerating forest residues at a small municipal district heating plant (6MW).

Science.gov (United States)

Pöykiö, R; Rönkkömäki, H; Nurmesniemi, H; Perämäki, P; Popov, K; Välimäki, I; Tuomi, T

2009-03-15

In Finland, the new limit values for maximal allowable heavy metal concentrations for materials used as an earth construction agent came into force in July 2006. These limit values are applied if ash is utilized, e.g. in roads, cycling paths, pavements, car parks, sport fields, etc. In this study we have determined the most important chemical and physical properties of the cyclone fly ash originating from the grate-fired boiler incinerating forest residues (i.e. wood chips, sawdust and bark) at a small municipal district heating plant (6 MW), Northern Finland. This study clearly shows that elements are enriched in cyclone fly ash, since the total element concentrations in the cyclone fly ash were within 0.2-10 times higher than those in the bottom ash. The total concentrations of Cd (25 mg kg(-1); d.w.), Zn (3630 mg kg(-1); d.w.), Ba (4260 mg kg(-1); d.w.) and Hg (1.7 mg kg(-1); d.w.) exceeded the limit values, and therefore the cyclone fly ash cannot be used as an earth construction agent. According to the leached amounts of Cr (38 mg kg(-1); d.w.), Zn (51 mg kg(-1); d.w.) and sulphate (50,000 mg kg(-1); d.w.), the cyclone fly ash is classified as a hazardous waste, and it has to be deposited in a hazardous waste landfill.

IRIS Toxicological Review of Hexahydro-1,3,5-Trinitro-1,3,5 ...

Science.gov (United States)

The IRIS Toxicological Review of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was released for external peer review in September 2016. The EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the RDX assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is undertaking an update of the Integrated Risk Information System (IRIS) health assessment for RDX. The outcome of this project is an updated Toxicological Review and IRIS Summary for RDX that will be entered into the IRIS database.

Toxicities of TNT and RDX to Terrestrial Plants in Five Soils with Contrasting Characteristics

Science.gov (United States)

2013-07-01

lettuce ( Lactuca sativa (L.)) and barley (Hordeum vulgare (L.)), respectively, at analytically determined soil concentrations up to and including 3320... sativa L.), Japanese millet (J. millet; Echinochloa crus-galli L. [Beauv.]), and perennial ryegrass (Lolium perenne L.) in five natural soils that...of the test. The test species in these studies were Medicago sativa (L.) var. Canada no. 1 (alfalfa), Echinochloa crus-galli (L.) P. Beauv. var

Polonium-210 and Caesium-137 in lynx (Lynx lynx), wolverine (Gulo gulo) and wolves (Canis lupus)

International Nuclear Information System (INIS)

Gjelsvik, Runhild; Holm, Elis; Kålås, John Atle; Persson, Bertil; Åsbrink, Jessica

2014-01-01

Wolves, lynx and wolverines are on the top of the food-chain in northern Scandinavia and Finland. 210 Po and 137 Cs have been analysed in samples of liver, kidney and muscle from 28 wolves from Sweden. In addition blood samples were taken from 27 wolves. In 9 of the wolves, samples of muscle, liver and blood were analysed for 210 Po. Samples of liver and muscle were collected from 16 lynx and 16 wolverines from Norway. The liver samples were analysed for 210 Po and 137 Cs. Only 137 Cs analyses were carried out for the muscle samples. The wolves were collected during the winter 2010 and 2011, while the samples for lynx and wolverines were all from 2011. The activity concentrations of 210 Po in wolves were higher for liver (range 20–523 Bq kg −1 d.w.) and kidney (range 24–942 Bq kg −1 d.w.) than muscle (range 1–43 Bq kg −1 d.w.) and blood (range 2–54 Bq kg −1 d.w.). Activity ratios, 210 Po/ 210 Pb, in wolf samples of muscle, liver and blood were in the ranges 2–77, 9–56 and 2–54. Using a wet weight ratio of 3.8 the maximal absorbed dose from 210 Po to wolf liver was estimated to 3500 μGy per year. Compared to wolf, the ranges of 210 Po in liver samples were lower in lynx (range 22–211 Bq kg −1 d.w.) and wolverine (range16–160 Bq kg −1 d.w.). Concentration of 137 Cs in wolf samples of muscle, liver, kidney and blood were in the ranges 70–8410 Bq kg −1 d.w., 36–4050 Bq kg −1 d.w., 31–3453 Bq kg −1 d.w. and 4–959 Bq kg −1 d.w., respectively. 137 Cs in lynx muscle and liver samples were in the ranges 44–13393 Bq kg −1 d.w. and 125–10260 Bq kg −1 d.w. The corresponding values for 137 Cs in wolverine were 22–3405 Bq kg −1 d.w. for liver and 53–4780 Bq kg −1 d.w. for muscle. The maximal absorbed dose from 137 Cs to lynx was estimated to 3000 μGy per year. - Highlights: • Annual doses from 210 Po are 1.4, 1.0 and 3.4 mGy for lynx, wolverine, and wolf. • Annual doses from 137 Cs are 3.3, 1.5 and 3.6 mGy for

DW3 Classical Music Resources: Managing Mozart on the Web.

Science.gov (United States)

Fineman, Yale

2001-01-01

Discusses the development of DW3 (Duke World Wide Web) Classical Music Resources, a vertical portal that comprises the most comprehensive collection of classical music resources on the Web with links to more than 2800 non-commercial pages/sites in over a dozen languages. Describes the hierarchical organization of subject headings and considers…

A human health risk assessment of rare earth elements in soil and vegetables from a mining area in Fujian Province, Southeast China.

Science.gov (United States)

Li, Xiaofei; Chen, Zhibiao; Chen, Zhiqiang; Zhang, Yonghe

2013-10-01

Contaminated food through dietary intake has become the main potential risk impacts on human health. This study investigated concentrations of rare earth elements (REEs) in soil, vegetables, human hair and blood, and assessed human health risk through vegetables consumption in the vicinity of a large-scale mining area located in Hetian Town of Changting County, Fujian Province, Southeast China. The results of the study included the following mean concentrations for total and bio-available REEs of 242.92 ± 68.98 (135.85-327.56)μg g(-1) and 118.59 ± 38.49 (57.89-158.96)μg g(-1) dry weight (dw) in agricultural soil, respectively, and total REEs of 3.58 ± 5.28 (0.07-64.42)μg g(-1) dw in vegetable samples. Concentrations of total REEs in blood and hair collected from the local residents ranged from 424.76 to 1274.80 μg L(-1) with an average of 689.74 ± 254.25 μg L(-1) and from 0.06 to 1.59 μg g(-1) with an average of 0.48 ± 0.59 μg g(-1) of the study, respectively. In addition, a significant correlation was observed between REEs in blood and corresponding soil samples (R(2)=0.6556, p0.05). Mean concentrations of REEs of 2.85 (0.59-10.24)μg L(-1) in well water from the local households was 53-fold than that in the drinking water of Fuzhou city (0.054 μg L(-1)). The health risk assessment indicated that vegetable consumption would not result in exceeding the safe values of estimate daily intake (EDI) REEs (100-110 μg kg(-1)d(-1)) for adults and children, but attention should be paid to monitoring human beings health in such rare earth mining areas due to long-term exposure to high dose REEs from food consumptions. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

The effects of soil amendments on heavy metal bioavailability in two contaminated Mediterranean soils

Energy Technology Data Exchange (ETDEWEB)

Walker, D.J.; Clemente, Rafael; Roig, Asuncion; Bernal, M.P

2003-04-01

The effects of organic amendments on metal bioavailability were not always related to their degree of humification. - Two heavy metal contaminated calcareous soils from the Mediterranean region of Spain were studied. One soil, from the province of Murcia, was characterised by very high total levels of Pb (1572 mg kg{sup -1}) and Zn (2602 mg kg{sup -1}), whilst the second, from Valencia, had elevated concentrations of Cu (72 mg kg{sup -1}) and Pb (190 mg kg{sup -1}). The effects of two contrasting organic amendments (fresh manure and mature compost) and the chelate ethylenediaminetetraacetic acid (EDTA) on soil fractionation of Cu, Fe, Mn, Pb and Zn, their uptake by plants and plant growth were determined. For Murcia soil, Brassica juncea (L.) Czern. was grown first, followed by radish (Raphanus sativus L.). For Valencia soil, Beta maritima L. was followed by radish. Bioavailability of metals was expressed in terms of concentrations extractable with 0.1 M CaCl{sub 2} or diethylenetriaminepentaacetic acid (DTPA). In the Murcia soil, heavy metal bioavailability was decreased more greatly by manure than by the highly-humified compost. EDTA (2 mmol kg{sup -1} soil) had only a limited effect on metal uptake by plants. The metal-solubilising effect of EDTA was shorter-lived in the less contaminated, more highly calcareous Valencia soil. When correlation coefficients were calculated for plant tissue and bioavailable metals, the clearest relationships were for Beta maritima and radish.

Per- and polyfluoroalkyl substances (PFASs) in water, soil and plants in wetlands and agricultural areas in Kampala, Uganda.

Science.gov (United States)

Dalahmeh, Sahar; Tirgani, Sana; Komakech, Allan John; Niwagaba, Charles B; Ahrens, Lutz

2018-08-01

Occurrence and concentrations of 26 per- and polyfluoroalkyl substances (PFASs) were evaluated in wastewater, surface water, soil and crop plants (yam (Dioscorea spp.), maize (Zea mays) and sugarcane (Saccharum officinarum)) in Nakivubo wetland and Lake Victoria at Kampala, Uganda. ∑PFAS concentrations in effluent from Bugolobi wastewater treatment plant (WWTP) were higher (5.6-9.1ngL -1 ) than in the corresponding influent (3.4-5.1ngL -1 ), indicating poor removal of PFASs within the WWTP. ∑PFAS concentrations decreased by a factor of approximately five between Nakivubo channel (8.5-12ngL -1 ) and Lake Victoria (1.0-2.5ngL -1 ), due to dilution, sorption to sediment and uptake by plants in the wetland. ∑PFAS concentrations were within the range 1700-7900pgg -1 dry weight (dw) in soil and 160pgg -1 dw (maize cobs) to 380pgg -1 dw (sugarcane stems) in plants. The dominant PFASs were perfluorohexanesulfonate (PFHxS) in wastewater, perfluorooctanoate (PFOA) in surface water, perfluorooctanesulfonate (PFOS) in soil and perfluoroheptanoate (PFHpA) and PFOA in different plant tissues, reflecting PFAS-specific partitioning behaviour in different matrices. Soil-water partitioning coefficient (log K d ) in wetland soil under yam was lowest for short-chain PFHxA (1.9-2.3Lkg -1 ) and increased with increasing chain length to 2.8-3.1Lkg -1 for perfluoroundecanoate (PFUnDA) and 2.8-3.1Lkg -1 for perfluoroctanesulfonate (PFOS). The log K oc values ranged between 2.2 and 3.6Lkg -1 , with the highest log K oc estimated for long-chain perfluorocarbon PFASs (i.e. PFUnDA 3.2-3.5Lkg -1 and PFOS 3.2-3.6Lkg -1 ). The concentration ratio (CR) between plants and soil was <1 for all PFASs and plant species, with the highest CR estimated for PFHpA (0.65-0.67) in sugarcane stem and PFBS (0.53-0.59) in yam root. Overall, this investigation demonstrated PFASs entry into the terrestrial food chain and drinking water resources in Kampala, Uganda. Source identification, assessment of

Multivariate regulation of soil CO2 and N2 O pulse emissions from agricultural soils.

Science.gov (United States)

Liang, Liyin L; Grantz, David A; Jenerette, G Darrel

2016-03-01

Climate and land-use models project increasing occurrence of high temperature and water deficit in both agricultural production systems and terrestrial ecosystems. Episodic soil wetting and subsequent drying may increase the occurrence and magnitude of pulsed biogeochemical activity, affecting carbon (C) and nitrogen (N) cycles and influencing greenhouse gas (GHG) emissions. In this study, we provide the first data to explore the responses of carbon dioxide (CO2 ) and nitrous oxide (N2 O) fluxes to (i) temperature, (ii) soil water content as percent water holding capacity (%WHC), (iii) substrate availability throughout, and (iv) multiple soil drying and rewetting (DW) events. Each of these factors and their interactions exerted effects on GHG emissions over a range of four (CO2 ) and six (N2 O) orders of magnitude. Maximal CO2 and N2 O fluxes were observed in environments combining intermediate %WHC, elevated temperature, and sufficient substrate availability. Amendments of C and N and their interactions significantly affected CO2 and N2 O fluxes and altered their temperature sensitivities (Q10 ) over successive DW cycles. C amendments significantly enhanced CO2 flux, reduced N2 O flux, and decreased the Q10 of both. N amendments had no effect on CO2 flux and increased N2 O flux, while significantly depressing the Q10 for CO2 , and having no effect on the Q10 for N2 O. The dynamics across DW cycles could be attributed to changes in soil microbial communities as the different responses to wetting events in specific group of microorganisms, to the altered substrate availabilities, or to both. The complex interactions among parameters influencing trace gas fluxes should be incorporated into next generation earth system models to improve estimation of GHG emissions. © 2015 John Wiley & Sons Ltd.

Scale and causes of lead contamination in Chinese tea

International Nuclear Information System (INIS)

Han Wenyan; Zhao Fangjie; Shi Yuanzhi; Ma Lifeng; Ruan Jianyun

2006-01-01

We investigated the scale and causes of Pb contamination in Chinese tea. Lead concentrations in 1225 tea samples collected nationally between 1999 and 2001 varied from -1 dry weight (DW), with 32% of the samples exceeding the national maximum permissible concentration (MPC) of 2.0 mg kg -1 DW and a significant difference between tea types. There was an increasing trend in tea Pb concentration from 1989 to 2000. Proximity to highway and surface dust contamination were found to cause elevated Pb concentrations in tea leaves. Furthermore, Pb concentration in tea leaves correlated significantly and positively with soil extractable Pb, and negatively with soil pH, suggesting that root uptake of Pb from soils also contributed to Pb accumulation in tea. Potential contributions to human Pb intake from drinking tea were small at the median or national MPC Pb values, but considerable at the highest concentration found in the study. - 32% of Chinese tea samples exceeded the national maximum permissible concentration for Pb

Environmental impact assessment of radionuclide and metal contamination at the former U sites Taboshar and Digmai, Tajikistan

International Nuclear Information System (INIS)

Skipperud, L.; Strømman, G.; Yunusov, M.; Stegnar, P.; Uralbekov, B.; Tilloboev, H.; Zjazjev, G.; Heier, L.S.; Rosseland, B.O.; Salbu, B.

2013-01-01

waters was in general low. In the Pit Lake, U was quite mobile (K d = 90 L/kg), followed by Ni (1.5 × 10 3 L/kg) and As (6 × 10 3 L/kg), Cu and Cd (1.5 × 10 4 L/kg), while Pb (3 × 10 5 L/kg) was rather inert. The transfer from soil to plant, TFs (kg/kg dw), was in general low, while the bioconcentration factor for water living Poaceae and for fish from water was relatively high (Pb 1.8 × 10 5 and Cd 1 × 10 4 ). These legacy sites, containing enhanced levels of natural radioactive material (TENORM) as well as heavy metals, may represent a hazard having a potential radiological and chemical impact on man and the environment, and measures should be taken to reduce the environmental risk to man and biota. -- Highlights: ► The U sites in Tajikistan are sources of contamination of the environment. ► The waters are enriched with respect to U and trace metals. ► The radiological situation in sites is a consequence of inappropriate management. ► At all sites restricted use of contaminated water sources should be applied

Irradiated Sewage Sludge for Production of Fennel Plants in Sandy Soil

International Nuclear Information System (INIS)

El-Motaium, R. A.; Abo El-Seoud, M. A.

2004-01-01

Irradiated sewage sludge (SS) has proved to be a useful organic fertilizer particularly for sandy soil. The objective of this study is to compare the response of fennel (Foeniculum vulgare L.) plants growing in sandy soil to different fertilizer regimes, organic vs. mineral. In a field experiment four levels (20, 40, 60, 80 t/ha) of irradiated and non-irradiated sewage sludge were incorporated into sandy soil, in addition to the control treatment (mineral fertilizer). Samples analysis included the biomass production at the vegetative and flowering stages, chlorophyll content, total and reducing sugars and heavy metals content of the shoots. The data indicate that the biomass production has dramatically increased as the sludge application rate increased in both irradiated and non-irradiated plots. However, the increase was significantly higher under all irradiated treatments than the corresponding rates of non-irradiated treatments at both the vegetative and flowering stages. Also, the biomass production at all levels of application was higher than the control, receiving mineral fertilizer. At the vegetative stage, the biomass values ranged from 3.1 g/plant for the control to 10.2 and 34.1 g/plant at 80 t/ha for non-irradiated and irradiated sewage sludge, respectively. Whereas, at the flowering stage the values ranged from 9.8 g/plant for the control to 23.9 and 65.1 g/plant at 80 t/ha for non-irradiated and irradiated sewage sludge, respectively. Total sugars, reducing sugar, non-reducing sugar, and chlorophyll content has increased as the sludge application rate increased. At 80t/ha application rate of irradiated sludge, the reducing sugars content was 29.39 mg/g DW at the vegetative stage and 37.85 mg/g DW at the flowering stage. Reducing sugars recorded lower values in the control plants, 14.54 mg/g DW at the vegetative stage and 18.78 mg/g DW at the flowering stage. Heavy metals (Zn, Fe, Pb, Cd) of the shoots was also determined. Sewage sludge was a good

Cesium-137 in soils and its soil-to-plant transfer rate

International Nuclear Information System (INIS)

Papastefanou, C.; Manolopoulou, M.; Charalambous, S.

1988-01-01

Measurements of fallout-derived 137 Cs in soils were made in the Valley of Ptolemais, North Greece after the Chernobyl nuclear reactor accident. The 137 Cs concentrations ranged between 290 Bq kg -1 and 7670 Bq kg -1 . It was found that the 137 Cs concentration is inversely proportional to 40 K concentration or potassium content of soils. Cesium-137 transfer coefficients from soil to plants (grass) ranged from 0.02 to 0.2

Spatial distribution of organochlorine contaminants in soil, sediment, and fish in Bikini and Enewetak Atolls of the Marshall Islands, Pacific Ocean.

Science.gov (United States)

Wang, Jun; Caccamise, Sarah A L; Wu, Liejun; Woodward, Lee Ann; Li, Qing X

2011-08-01

Several nuclear tests were performed at Enewetak and Bikini Atolls in the Marshall Islands between 1946 and 1958. The events at Bikini Atoll involved several ships that were tested for durability during nuclear explosions, and 24 vessels now rest on the bottom of the Bikini lagoon. Nine soil samples were collected from different areas on the two islands of the atoll, and eighteen sediment, nine fish, and one lobster were collected in the vicinity of the sunken ships. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polychlorinated terphenyls (PCTs) in these samples were analyzed using gas chromatography/ion trap mass spectrometry (GC/ITMS). The average recoveries ranged from 78% to 104% for the different PCB congeners. The limits of detection (LOD) for PCBs, PCTs, DDE, DDT, and dieldrin ranged 10-50 pg g(-1). Some fish from Enewetak contained PCBs at a concentration range of 37-137 ng g(-1), dry weight (dw), and most of the soils from Enewetak showed evidence of PCBs (22-392 ng g(-1)dw). Most of the Bikini lagoon sediment samples contained PCBs, and the highest was the one collected from around the Saratoga, an aircraft carrier (1555 ng g(-1)dw). Some of the fish samples, most of the soil samples, and only one of the sediment samples contained 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and PCBs. In addition to PCBs, the soils from Enewetak Atoll contained PCTs. PCTs were not detected in the sediment samples from Bikini Atoll. The results suggest local pollution sources of PCBs, PCTs, and OCPs. Copyright © 2011. Published by Elsevier Ltd.

Remediation of Cd-contaminated soil around metal sulfide mines

Science.gov (United States)

Lu, Xinzhe; Hu, Xuefeng; Kang, Zhanjun; Luo, Fan

2017-04-01

The mines of metal sulfides are widely distributed in the southwestern part of Zhejiang Province, Southeast China. The activities of mining, however, often lead to the severe pollution of heavy metals in soils, especially Cd contamination. According to our field investigations, the spatial distribution of Cd-contaminated soils is highly consistent with the presence of metal sulfide mines in the areas, further proving that the mining activities are responsible for Cd accumulation in the soils. To study the remediation of Cd-contaminated soils, a paddy field nearby large sulfide mines, with soil pH 6 and Cd more than 1.56 mg kg-1, five times higher than the national recommended threshold, was selected. Plastic boards were deeply inserted into soil to separate the field and make experimental plots, with each plot being 4 m×4 m. Six treatments, TK01˜TK06, were designed to study the effects of different experimental materials on remediating Cd-contaminated soils. The treatment of TK01 was the addition of 100 kg zeolites to the plot; TK02, 100 kg apatites; TK03, 100 kg humid manure; TK04, 50 kg zeolites + 50 kg apatites; TK05, 50 kg zeolites + 50 kg humid manure; TK06 was blank control (CK). One month after the treatments, soil samples at the plots were collected to study the possible change of chemical forms of Cd in the soils. The results indicated that these treatments reduced the content of available Cd in the soils effectively, by a decreasing sequence of TK04 (33%) > TK02 (25%) > TK01 (23%) > TK05 (22%) > TK03 (15%), on the basis of CK. Correspondingly, the treatments also reduced the content of Cd in rice grains significantly, by a similar decreasing sequence of TK04 (83%) > TK02 (77%) > TK05 (63%) > TK01 (47%) > TK03 (27%). The content of Cd in the rice grains was 0.071 mg kg-1, 0.094 mg kg-1, 0.159 mg kg-1, 0.22 mg kg-1 and 0.306 mg kg-1, respectively, compared with CK, 0.418 mg kg-1. This experiment suggested that the reduction of available Cd in the soils is

砒素を溶出する泥岩のモエジマシダによるファイトレメディエーションに関するポット実験

OpenAIRE

渡邉, 彩; 榊原, 正幸; 佐野, 栄; 近藤, 敏仁; 井上, 雅裕; 堀, 利栄; 鈴木, 哲也; 竹花, 大介

2005-01-01

Phytoremediation is the use of plants for the in situ cleanup of contaminated soils, sediments, and ground water. Pot-scale experiment evaluated phytoremediation by Pteris vittata L. (Chinese brake fern) for mudstone containing arsenic (12.3 mg/kg-DW) of the Hakobuchi Group in the Yubari City, central Hokkaido, Japan. In this experiment, fronds of Pteris vittata L. were taken after 18 weeks growth in soil. The following properties became clear after examining the experimental results. (1) The...

Uptake of 137Cs from coniferous forest soil by sheep's fescue in pot experiment

International Nuclear Information System (INIS)

Fawaris, B. H.; Johanson, K. J.

1994-01-01

The uptake of Chernobyl fallout radiocaesium ( 137 Cs) from forest soils with low nutrients, high organic matter content, and acidic pH were examined in pot experiments. Results of sheep's fescue (Festuca ovina) two harvests after growing period of 13 weeks each, showed a slight variation in the 137 Cs uptake. Transfer factor (TF) for 137 Cs based upon soil-to-plant relationships calculated, (Bqkg -1 plant DW/Bqkg -1 soil DW). The ranges were from 0.03 to 3.43 with a mean of 0.34 ± 0.31 for first cut and from 0.03 to 2.28 with a mean of 0.36 ± 0.33 for second cut. Variation in the uptake of 137 Cs by sheep's fescue grass might be due to the influence of soil pH and OM % in conjunction with soil moisture. The effect of potassium (K + ), stable caesium (Cs + ), and ammonium (NH 4 + ) that were added as chlorides on 137 Cs uptake by sheep's fescue were also tested in pot experiment under the same conditions of previous set-up. Results from three harvests after growing period of 13 weeks each, demonstrated that K + reduced the uptake of 137 Cs. In contrast the addition of both stable Cs + and NH 4 + found to enhance 137 Cs uptake by sheep's fescue. (author)

Chemical changes in agricultural soils of Korea: data review and suggested countermeasures.

Science.gov (United States)

Jo, I S; Koh, M H

2004-01-01

The monitoring of chemical properties, including heavy metals, in soils is necessary if better management and remediation practices are to be established for polluted soils. The National Institute of Agricultural Science and Technology initiated a monitoring study that investigated fertility and heavy metal contents of the benchmarked soils. The study covered paddy soils, upland soils, and horticultural soils in the plastic film houses, and orchard soils throughout the Korea from 1990 to 1998. Likewise, 4047 samples of paddy and 2534 samples of plastic house in 1999 and 2000 were analyzed through the Soil Environment Conservation Act. Soil chemical properties such as pH, organic matter, available phosphate and extractable calcium, magnesium and potassium contents, and heavy metal contents such as cadmium, copper, lead, zinc, arsenic, mercury, and cobalt contents were analyzed. The study showed that the average contents of organic matter, available phosphate, and extractable potassium rapidly increased in plastic house soils than in upland or paddy soils. Two kinds of fertilizer recommendation systems were established for the study: the standard levels by national soil average data for 77 crops and the recommendation by soil test for 70 crops. Standard nitrogen fertilizer application levels for cereal crops changed from 94 kg/ha in 1960s, 99 kg/ha in 1970s, 110 kg/ha in 1980s to 90 kg/ha in 1990s. The K2O-fertilizer also changed from 67 kg/ha in 1960s, 76 kg/ha in 1970s, 92 kg/ha in 1980s, and only 44 kg/ha in 1990s. In rice paddy fields, the average contents of Cd, Cu, Pb, and Zn in surface soils (0-15 cm depth) were 0.11 mg kg(-1) (ranged from 0 to 1.01), 4.70 mg kg(-1) (0-41.59), 4.84 mg kg(-1) (0-66.44), and 4.47 mg kg(-1) (0-96.70), respectively. In the uplands, the average contents of Cd, Cu, Pb, Zn, and As in surface soils (0-15 cm depth) were 0.135 mg kg(-1) (ranged from 0 to 0.660), 2.77 mg kg(-1) (0.07-78.24), 3.47 mg kg(-1) (0-43.00), 10.70 mg kg(-1) (0

Evaluation of natural radioactivity in soil, sediment and water samples of Niger Delta (Biseni) flood plain lakes, Nigeria

Energy Technology Data Exchange (ETDEWEB)

Agbalagba, E.O., E-mail: ezek64@yahoo.com [Department of Physics, Federal University of Petroleum Resources, Effurun (Nigeria); Onoja, R.A. [Dept. of Radiation Biophysics, Centre for Energy Research and Training, Ahmadu Bello University, Zaria (Nigeria)

2011-07-15

This paper presents the findings of a baseline study undertaken to evaluate the natural radioactivity levels in soil, sediment and water samples in four flood plain lakes of the Niger Delta using a hyper pure germanium (HPGe) detector. The activity profile of radionuclides shows low activity across the study area. The mean activity level of the natural radionuclides {sup 226}Ra, {sup 232}Th and {sup 40}K is 20 {+-} 3, 20 {+-} 3 and 180 {+-} 50 Bq kg{sup -1}, respectively. These values are well within values reported elsewhere in the country and in other countries with similar environments. The study also examined some radiation hazard indices. The mean values obtained are, 76 {+-} 14 Bq kg{sup -1}, 30 {+-} 5.5 {eta}Gy h{sup -1}, 37 {+-} 6.8 {mu}Sv y{sup -1}, 0.17 and 0.23 for Radium Equivalent Activity (Ra{sub eq}), Absorbed Dose Rates (D), Annual Effective Dose Rates (E{sub ff} Dose), External Hazard Index (H{sub ex}) and Internal Hazard Index (H{sub in}) respectively. All the health hazard indices are well below their recommended limits. The soil and sediments from the study area provide no excessive exposures for inhabitants and can be used as construction materials without posing any significant radiological threat to the population. The water is radiologically safe for domestic and industrial use. The paper recommends further studies to estimate internal and external doses from other suspected radiological sources to the population of the Biseni kingdom. - Highlights: > The activity profile of the radionuclides has clearly showed the existence of low activity in the study area. > The average activity concentration of {sup 226}Ra, {sup 232}Th and {sup 40}K is 20 {+-} 3, 20 {+-} 3 and 185 {+-} 47 Bq kg{sup -1} DW (or L{sup -1}) respectively. > These values compared well with other values obtained within Nigeria and other countries of the world. > The soils and sediments of the area have no immediate health implication on the inhabitants. > This work has

Biaccumulation and tolerance of heavy metals on the tropical earthworm, Allobophora sp. after exposed to contaminated soil from oil mine waste

Science.gov (United States)

Suhendrayatna; Darusman; Raihannah; Nurmala, D.

2018-04-01

In this study, the impact of contaminated soil from oil mine waste on survival, behavior, tolerance, and bioaccumulation of heavy metals by the tropical earthworm, Allobophora sp. has been quantified. Earthworm was isolated from heavy metals-contaminated soil, cultured in laboratory condition, and exposed to contaminated soil from oil mine waste for a couple of months. The behavior and response of earthworms to contaminated soil was monitored for 28 days and evaluated by the response criteria was expressed in scale index (SI) referred to Langdon method. Resistance test of the earthworm (LC50) to heavy metals also conducted with variation soil concentrations of 100%, 50%, 25%, 12.5%, and 6.25%, and 0% (Control). Results showed that contaminated soil extremely affected to the earthworm live, especially length and their body weight. The Lethal Concentration 50% (LC50) of earthworm against contaminated soil was 19.05% (w/w). When exposed to contaminated soil, earthworm accumulated chromium, barium, and manganese at the concentration of 88; 92.2; and 280 mg/kg-DW, respectively. Based on these results, earthworm Allobophora sp. has potential to reduce heavy metals from contaminated soil in the field of bioremediation process.

USE OF SERIAL ANALYSIS OF GENE EXPRESSION (SAGE) TO STUDY GENETIC RESPONSES TO THE PRESENCE OF THE TNT OR RDX BY ARABIDOPSIS THALIANA

Science.gov (United States)

Phytoremediation is currently being explored for its potential to clean-up of the large number of military sites that have been contaminated by explosives such as 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). Although some of the enzymes responsi...

Application of ground bone and sheep manure on soils from two contaminated sites and influence on oat growth, uranium and radium uptake and translocation

Science.gov (United States)

Abreu, M. M.; Pacheco, A.; Santos, E.; Magalhães, M. C. F.

2012-04-01

Past radium and uranium exploitation and processing in Urgeiriça mine and radium processing in Barracão (centre-north of Portugal) led to soils and waters contamination. Most of the soils, located in rural areas, are cultivated for vegetables, fruit trees, and/or pasturage, and the waters used for soils irrigation. The objective of this work was to evaluate the capacity of organic amendments and hydroxiapatite to reduce the soil available fraction of Utotal and 226Ra in soils of two areas after four months of incubation. Influence on oat growth, uranium and radium uptake and translocation was also studied. Pot experiments, under controlled conditions, were undertaken during four months of incubation at 70% of the soil water-holding capacity. Urgeiriça (Urg) and Barracão (Brc) soils containing large concentrations of Utotal (635 and 189 mg/kg, respectively), and 226Ra (2310 and 1770 Bq/kg, respectively) were used. The available fraction of these elements, extracted with ammonium acetate, corresponds to: 90 and 20% of total concentration of uranium and radium, respectively, for Urgeiriça soil, and 19 and 43% of total concentration of uranium and radium, respectively, for Barracão soil. Fine ground bone (FB), sheep manure (OM), and vermicompost (V) single or mixtures were used as amendments. Control (soil) and treatments were made in triplicate: (T1) soil+96 g FB/kg of soil; (T2) soil+168 g OM/kg of soil; (T3) soil+168 g OM/kg of soil+96 g FB/kg of soil; (T4) soil+168 g V/kg of soil. After incubation, soil subsamples were analysed for pH, electric conductivity (EC), and available fractions of Utotal and 226Ra. The remaining soils were used for oat (Avena sativa L.) cultivation. Soils had pH 5.15 (Urg) and 6.04 (Brc), and EC 57.3 µS/cm (Urg) and 36.3 µS/cm (Brc). After incubation soil pH increased to a maximum of 6.82 (Urg) and 7.10 (Brc) in amended samples, and EC showed a large increase (15-19 times) when compared to the control. A decrease of the available

Use of different surface covering materials to enhance removal of radiocaesium in plants and upper soil from orchards in Fukushima prefecture.

Science.gov (United States)

Sato, Mamoru; Akai, Hiroko; Saito, Yuichi; Takase, Tsugiko; Kikunaga, Hidetoshi; Sekiya, Nobuhito; Ohtsuki, Tsutomu; Yamaguchi, Katsuhiko

2017-04-04

The effectiveness of a decontamination methodology whereby herbaceous plants were grown through different materials covering the soil surface followed by subsequent removal of the material, associated plant tissues and attached soil on 137 Cs removal from soil was evaluated. Revegetation netting sown with Kentucky bluegrass and white clover had a high effectiveness in 137 Cs removal when rolling up the plants, roots, and rhizosphere soil approximately 6 months after sowing. The removal rate was lower when there was higher 137 Cs vertical migration down the soil profile. The maximum removal effectiveness of 93.1% was observed by rolling up fertilized Kentucky bluegrass with a well-developed root mat without netting, indicating that applying nutrients to encourage the development of roots or root mats in the 3 cm topsoil rhizosphere is an efficient technology to increase the decontamination effect of plant removal in orchards. Netting and weeding were able to remove up to 80% of 137 Cs in the soil without the use of heavy machinery. There was a significant relationship between the removal ratio and the removed soil weight per area. Using the relationship on the site below the canopy, removal of 14.3 kg m -2 DW soil would achieve a removal ratio of 80%. The effectiveness of the technique will decrease with time as radiocaesium migrates down the soil profile but this would be expected to occur slowly in many soils. Copyright © 2017 Elsevier Ltd. All rights reserved.

Connective tissue of cervical carcinoma xenografts: associations with tumor hypoxia and interstitial fluid pressure and its assessment by DCE-MRI and DW-MRI.

Science.gov (United States)

Hompland, Tord; Ellingsen, Christine; Galappathi, Kanthi; Rofstad, Einar K

2014-01-01

Abstract Background. A high fraction of stroma in malignant tissues is associated with tumor progression, metastasis, and poor prognosis. Possible correlations between the stromal and physiologic microenvironments of tumors and the potential of dynamic contrast-enhanced (DCE) and diffusion-weighted (DW) magnetic resonance imaging (MRI) in quantification of the stromal microenvironment were investigated in this study. Material and methods. CK-160 cervical carcinoma xenografts were used as preclinical tumor model. A total of 43 tumors were included in the study, and of these tumors, 17 were used to search for correlations between the stromal and physiologic microenvironments, 11 were subjected to DCE-MRI, and 15 were subjected to DW-MRI. DCE-MRI and DW-MRI were carried out at 1.5 T with a clinical MR scanner and a slotted tube resonator transceiver coil constructed for mice. Fraction of connective tissue (CTFCol) and fraction of hypoxic tissue (HFPim) were determined by immunohistochemistry. A Millar SPC 320 catheter was used to measure tumor interstitial fluid pressure (IFP). Results. CTFCol showed a positive correlation to IFP and an inverse correlation to HFPim. The apparent diffusion coefficient assessed by DW-MRI was inversely correlated to CTFCol, whereas no correlation was found between DCE-MRI-derived parameters and CTFCol. Conclusion. DW-MRI is a potentially useful method for characterizing the stromal microenvironment of tumors.

Incorporation of Biochar Carbon into Stable Soil Aggregates: The Role of Clay Mineralogy and Other Soil Characteristics

Institute of Scientific and Technical Information of China (English)

Charlene N.KELLY; Joseph BENJAMIN; Francisco C.CALDER(O)N; Maysoon M.MIKHA; David W.RUTHERFORD; Colleen E.ROSTAD

2017-01-01

Aggregation and structure plav key roles in water-holding capacity and stability of soils.In this study,the incorporation of carbon (C) from switchgrass biochar into stable aggregate size fractions was assessed in an Aridisol (from Colorado,USA) dominated by 2:1 clays and an Alfisol (from Virginia,USA) containing weathered mixed 1∶1 and 2∶1 mineralogy,to evaluate the effect of biochar addition on soil characteristics.The biochar was applied at 4 levels,0,25,50,and 100 g kg-1,to the soils grown with wheat in a growth chamber experiment.The changes in soil strength and water-holding capacity using water release curves were measured.In the Colorado soil,the proportion of soil occurring in large aggregates decreased,with concomitant increases in small size fractions.No changes in aggregate size fractions occurred in the Virginia soil.In the Colorado soil,C content increased from 3.3 to 16.8 g kg-1,whereas in the ＜ 53 μm fraction C content increased from 5.7 to 22.6 g kg-1 with 100 g kg-1 biochar addition.In the Virginia soil,C content within aggregate size fractions increased for each size fraction,except the ＞ 2 000 μm fraction.The greatest increase (from 6.2 to 22.0 g kg-1) occurred in the 53-250 μm fraction.The results indicated that C was incorporated into larger aggregates in the Virginia soil,but remained largely unassociated to soil particles in the Colorado soil.Biochar addition had no significant effect on water-holding capacity or strength measurements.Adding biochar to more weathered soils with high native soil organic content may result in greater stabilization of incorporated C and result in less loss because of erosion and transport,compared with the soils dominated by 2∶1 clays and low native soil organic content.

Microbial community dynamics during the bioremediation process of chlorimuron-ethyl-contaminated soil by Hansschlegelia sp. strain CHL1.

Directory of Open Access Journals (Sweden)

Liqiang Yang

Full Text Available Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ.

Microbial Community Dynamics during the Bioremediation Process of Chlorimuron-Ethyl-Contaminated Soil by Hansschlegelia sp. Strain CHL1

Science.gov (United States)

Yang, Liqiang; Li, Xinyu; Li, Xu; Su, Zhencheng; Zhang, Chenggang; Zhang, Huiwen

2015-01-01

Long-term and excessive application of chlorimuron-ethyl has led to a series of environmental problems. Strain Hansschlegelia sp. CHL1, a highly efficient chlorimuron-ethyl degrading bacterium isolated in our previous study, was employed in the current soil bioremediation study. The residues of chlorimuron-ethyl in soils were detected, and the changes of soil microbial communities were investigated by phospholipid fatty acid (PLFA) analysis. The results showed that strain CHL1 exhibited significant chlorimuron-ethyl degradation ability at wide range of concentrations between 10μg kg-1 and 1000μg kg-1. High concentrations of chlorimuron-ethyl significantly decreased the total concentration of PLFAs and the Shannon-Wiener indices and increased the stress level of microbes in soils. The inoculation with strain CHL1, however, reduced the inhibition on soil microbes caused by chlorimuron-ethyl. The results demonstrated that strain CHL1 is effective in the remediation of chlorimuron-ethyl-contaminated soil, and has the potential to remediate chlorimuron-ethyl contaminated soils in situ. PMID:25689050

90Sr and 137Cs in environmental samples from Dolon near the Semipalatinsk Nuclear Test Site.

Science.gov (United States)

Gastberger, M; Steinhäusler, F; Gerzabek, M H; Hubmer, A; Lettner, H

2000-09-01

The (90)Sr and (137)Cs activities of soil, plant, and milk samples from the village of Dolon, located close to the Semipalatinsk Nuclear Test Site in Kazakhstan, were determined. The areal deposition at the nine sampling sites is in the range of sites both nuclides mainly have remained in the top 6 cm of the soil profiles; at others they were partly transported into deeper soil layers since the deposition. For most of the samples the (90)Sr yield after destruction of the soil matrix is significantly higher than after extracting with 6 M HCl indicating that (90)Sr is partly associated with fused silicates. The low mean (90)Sr activity concentrations of vegetation samples (14 Bq kg(-1) dw) and milk samples (0.05 Bq kg(-1) fw) suggest that this has favorable consequences in terms of limiting its bioavailability.

Fate of fertilizer nitrogen in soil-plant system under irrigating condition. Pt.1: Effect of nitrogen level

International Nuclear Information System (INIS)

Chen Qing; Wen Xianfang; Zheng Xingyun; Pan Jiarong

1997-01-01

Three nitrogen fertilization levels including optimum rate of nitrogen applied (N1.0, 150 kg N·ha -1 ), 150% of optimum rate (N1.5, 225 kg N·ha -1 ) and 50% of optimum rate (N0.5, 75 kg N·ha -1 ) were selected to determine the fate of nitrogen in soil plant system by 15 N technique in 1994∼1995 field experiment which was conducted in Shijiazhuang. The results showed that under irrigated condition the nitrogen use efficiencies (NUE) of ammonium bicarbonate by winter wheat in fertilized treatments were 38.5%, 32.3% and 22.4% respectively, while the highest NUE of winter wheat was found in N0.5 treatment due to a relatively high fertility. The highest yield (6.8 x 10 3 kg grain·ha -1 , 14.7 x 10 3 kg top·ha -1 ) was obtained in N1.0 treatment, but nitrogen uptake and grain yield in N1.5 treatment were lower than those of other fertilizer treatments and there was no significant difference between N0.0 and N1.5 in grain yield. the highest residue of fertilizer N was determined in N1.5 treatment, of which 46% existed in the top layer of the soil (0∼50 cm). There was no significant difference in residual fertilizer N in soil between the other two treatments (31.28% in N0.5, 31.12% in N1.0). In 15 N balance calculation, the unaccounted part of applied N which was leaching down 50 cm in the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, the soil profile as nitrate or gaseous loss through volatilization, denitrification were 30.20%, 36.56%, 31.25% in N0.5, N1.5 treatments, respectively. It is very important to control residual N in order to prevent N pollution and promote the growth of next crop

Carbon flow from volcanic CO2 into soil microbial communities of a wetland mofette

Science.gov (United States)

Beulig, Felix; Heuer, Verena B.; Akob, Denise M.; Viehweger, Bernhard; Elvert, Marcus; Herrmann, Martina; Hinrichs, Kai-Uwe; Küsel, Kirsten

2015-01-01

Effects of extremely high carbon dioxide (CO2) concentrations on soil microbial communities and associated processes are largely unknown. We studied a wetland area affected by spots of subcrustal CO2 degassing (mofettes) with focus on anaerobic autotrophic methanogenesis and acetogenesis because the pore gas phase was largely hypoxic. Compared with a reference soil, the mofette was more acidic (ΔpH ~0.8), strongly enriched in organic carbon (up to 10 times), and exhibited lower prokaryotic diversity. It was dominated by methanogens and subdivision 1Acidobacteria, which likely thrived under stable hypoxia and acidic pH. Anoxic incubations revealed enhanced formation of acetate and methane (CH4) from hydrogen (H2) and CO2 consistent with elevated CH4 and acetate levels in the mofette soil. 13CO2 mofette soil incubations showed high label incorporations with ~512 ng13C g (dry weight (dw)) soil−1 d−1 into the bulk soil and up to 10.7 ng 13C g (dw) soil−1 d−1 into almost all analyzed bacterial lipids. Incorporation of CO2-derived carbon into archaeal lipids was much lower and restricted to the first 10 cm of the soil. DNA-SIP analysis revealed that acidophilic methanogens affiliated withMethanoregulaceae and hitherto unknown acetogens appeared to be involved in the chemolithoautotrophic utilization of 13CO2. Subdivision 1 Acidobacteriaceae assimilated 13CO2 likely via anaplerotic reactions because Acidobacteriaceae are not known to harbor enzymatic pathways for autotrophic CO2 assimilation. We conclude that CO2-induced geochemical changes promoted anaerobic and acidophilic organisms and altered carbon turnover in affected soils.

Concentrations and distribution of polybrominated diphenyl ethers (PBDEs) in soils and plants from a deca-BDE manufacturing factory in China.

Science.gov (United States)

Li, Yuan; Niu, Shan; Hai, Reti; Li, Meng

2015-01-01

Residues of polybrominated diphenyl ethers (PBDEs), including eight PBDE congeners, were investigated in soils and plants from a deca-BDE manufacturing factory located in the Shandong province of China to evaluate and discuss their pollution level and distribution. Total concentrations in topsoil ranged from 17.0 to 146 μg g(-1) dry weight (dw) with a mean value of 58.7 μg g(-1) dw. BDE-209 was the dominant congener in soils, accounting for 55.63-99.27 % of the total PBDEs. Concentrations and congener patterns in soils varied among different soil depths. Concentration levels in topsoil are high and the heavy accumulation in deep soil also can be observed, even for some sites, the concentrations in 50-100 cm depth are higher than in topsoil. In plant samples, total PBDE concentrations and the proportion of BDE-209 were high (69.92-99.10 %). The extent of pollution by PBDEs in the deca-BDE production factory was higher than in other regions, and the environmental risk caused by the production of deca-BDE is of concern. This is the first study to report pollution of PBDEs in soils and plants from the vicinity of a deca-BDE manufacturing factory.

Copper phytoextraction in tandem with oilseed production using commercial cultivars and mutant lines of sunflower.

Science.gov (United States)

Kolbas, A; Mench, M; Herzig, R; Nehnevajova, E; Bes, C M

2011-01-01

Use of sunflower (Helianthus annuus L.) for Cu phytoextraction and oilseed production on Cu-contaminated topsoils was investigated in afield trial at a former wood preservation site. Six commercial cultivars and two mutant lines were cultivated in plots with and without the addition of compost (5% w/w) and dolomitic limestone (0.2% w/w). Total soil Cu ranged from 163 to 1170 mg kg(-1). In soil solutions, Cu concentration varied between 0.16-0.93 mg L(-1). The amendment increased soil pH, reduced Cu exposure and promoted sunflower growth. Stem length, shoot and capitulum biomasses, seed yield, and shoot and leaf Cu concentrations were measured. At low total soil Cu, shoot Cu mineralomass was higher in commercial cultivars, Le., Salut, Energic, and Countri, whereas competition and shading affected morphological traits of mutants. Based on shoot yield (7 Mg DW ha(-1)) and Cu concentration, the highest removal was 59 g Cu ha(-1). At high total soil Cu, shoot Cu mineralomass peaked for mutants (e.g., 52 g Cu ha(-1) for Mutant 1 line) and cultivars Energic and Countri. Energic seed yield (3.9 Mg air-DW ha(-1)) would be sufficient to produce oil Phenotype traits and shoot Cu removal depended on sunflower types and Cu exposure.

Levels and transfer of {sup 210}Po and {sup 210}Pb in Nordic terrestrial ecosystems

Energy Technology Data Exchange (ETDEWEB)

Brown, J.E., E-mail: justin.brown@nrpa.n [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Gjelsvik, R. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway); Roos, P. [RISO-DTU P.O. Box 49 DK-4000 Roskilde (Denmark); Kalas, J.A. [Norwegian Institute for Nature Research (NINA), Tungasletta 2, 7485 Trondheim (Norway); Outola, I. [STUK, Laippatie 4/P.O. BOX 14, 00881 Helsinki (Finland); Holm, E. [Norwegian Radiation Protection Authority, PO Box 55, N-1332, Osteras (Norway)

2011-05-15

Recent developments regarding environmental impact assessment methodologies for radioactivity have precipitated the need for information on levels of naturally occurring radionuclides within and transfer to wild flora and fauna. The objectives of this study were therefore to determine activity concentrations of the main dose forming radionuclides {sup 210}Po and {sup 210}Pb in biota from terrestrial ecosystems thus providing insight into the behaviour of these radioisotopes. Samples of soil, plants and animals were collected at Dovrefjell, Central Norway and Olkiluoto, Finland. Soil profiles from Dovrefjell exhibited an approximately exponential fall in {sup 210}Pb activity concentrations from elevated levels in humus/surface soils to 'supported' levels at depth. Activity concentrations of {sup 210}Po in fauna (invertebrates, mammals, birds) ranged between 2 and 123 Bq kg{sup -1} d.w. and in plants and lichens between 20 and 138 Bq kg{sup -1} d.w. The results showed that soil humus is an important reservoir for {sup 210}Po and {sup 210}Pb and that fauna in close contact with this media may also exhibit elevated levels of {sup 210}Po. Concentration ratios appear to have limited applicability with regards to prediction of activity concentrations of {sup 210}Po in invertebrates and vertebrates. Biokinetic models may provide a tool to explore in a more mechanistic way the behaviour of {sup 210}Po in this system.

Imaging children suffering from lymphoma: an evaluation of different 18F-FDG PET/MRI protocols compared to whole-body DW-MRI.

Science.gov (United States)

Kirchner, Julian; Deuschl, Cornelius; Schweiger, Bernd; Herrmann, Ken; Forsting, Michael; Buchbender, Christian; Antoch, Gerald; Umutlu, Lale

2017-09-01

The objectives of this study were to evaluate and compare the diagnostic potential of different PET/MRI reading protocols, entailing non-enhanced / contrast-enhanced and diffusion-weighted 18 F-FDG PET/MR imaging and whole-body diffusion-weighted MRI for lesion detection and determination of the tumor stage in pediatric lymphoma patients. A total of 28 18 F-FDG PET/MRI datasets were included for analysis of four different reading protocols: (1) PET/MRI utilizing sole unenhanced T2w and T1w imaging, (2) PET/MRI utilizing additional contrast enhanced sequences, (3) PET/MR imaging utilizing unenhanced, contrast enhanced and DW imaging or (4) WB-DW-MRI. Statistical analyses were performed on a per-patient and a per-lesion basis. Follow-up and prior examinations as well as histopathology served as reference standards. PET/MRI correctly identified all 17 examinations with active lymphoma disease, while WB-DW-MRI correctly identified 15/17 examinations. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 96%, 96.5%, 97%, 95%, and 96% for PET/MRI 1 ; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI 2 ; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI 3 and 77%, 96%, 96%, 78.5% and 86% for MRI-DWI. 18 F-FDG PET/MRI is superior to WB-DW-MRI in staging pediatric lymphoma patients. Neither application of contrast media nor DWI leads to a noticeable improvement of the diagnostic accuracy of PET/MRI. Thus, unenhanced PET/MRI may play a crucial role for the diagnostic work-up of pediatric lymphoma patients in the future.

Toxicity of abamectin and doramectin to soil invertebrates

Energy Technology Data Exchange (ETDEWEB)

Kolar, Lucija [Laboratory of Forensic Toxicology and Ecotoxicology, Veterinary Faculty, University of Ljubljana, Gerbiceva 60, SI-1000 Ljubljana (Slovenia); Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: lucija.kolar@vf.uni-lj.si; Kozuh Erzen, Nevenka [Laboratory of Forensic Toxicology and Ecotoxicology, Veterinary Faculty, University of Ljubljana, Gerbiceva 60, SI-1000 Ljubljana (Slovenia)], E-mail: nevenka.kozuh@vf.uni-lj.si; Hogerwerf, Lenny [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: l.hogerwerf@students.uu.nl; Gestel, Cornelis A.M. van [Institute of Ecological Science, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)], E-mail: kees.van.gestel@ecology.falw.vu.nl

2008-01-15

This study aimed at determining the toxicity of avermectins to soil invertebrates in soil and in faeces from recently treated sheep. Abamectin was more toxic than doramectin. In soil, earthworms (Eisenia andrei) were most affected with LC50s of 18 and 228 mg/kg dry soil, respectively, while LC50s were 67-111 and >300 mg/kg for springtails (Folsomia candida), isopods (Porcellio scaber) and enchytraeids (Enchytraeus crypticus). EC50s for the effect on reproduction of springtails and enchytraeids were 13 and 38 mg/kg, respectively for abamectin, and 42 and 170 mg/kg for doramectin. For earthworms, NOEC was 10 and 8.4 mg/kg for abamectin and doramectin effects on body weight. When exposed in faeces, springtails and enchytraeids gave LC50s and EC50s of 1.0-1.4 and 0.94-1.1 mg/kg dry faeces for abamectin and 2.2->2.4 mg/kg for doramectin. Earthworm reproduction was not affected. This study indicates a potential risk of avermectins for soil invertebrates colonizing faeces from recently treated sheep. - Avermectins may pose a risk to soil invertebrates colonizing faeces from recently treated sheep.

Toxicity of abamectin and doramectin to soil invertebrates

International Nuclear Information System (INIS)

Kolar, Lucija; Kozuh Erzen, Nevenka; Hogerwerf, Lenny; Gestel, Cornelis A.M. van

2008-01-01

This study aimed at determining the toxicity of avermectins to soil invertebrates in soil and in faeces from recently treated sheep. Abamectin was more toxic than doramectin. In soil, earthworms (Eisenia andrei) were most affected with LC50s of 18 and 228 mg/kg dry soil, respectively, while LC50s were 67-111 and >300 mg/kg for springtails (Folsomia candida), isopods (Porcellio scaber) and enchytraeids (Enchytraeus crypticus). EC50s for the effect on reproduction of springtails and enchytraeids were 13 and 38 mg/kg, respectively for abamectin, and 42 and 170 mg/kg for doramectin. For earthworms, NOEC was 10 and 8.4 mg/kg for abamectin and doramectin effects on body weight. When exposed in faeces, springtails and enchytraeids gave LC50s and EC50s of 1.0-1.4 and 0.94-1.1 mg/kg dry faeces for abamectin and 2.2->2.4 mg/kg for doramectin. Earthworm reproduction was not affected. This study indicates a potential risk of avermectins for soil invertebrates colonizing faeces from recently treated sheep. - Avermectins may pose a risk to soil invertebrates colonizing faeces from recently treated sheep

Evaluation of some pollutant levels in environmental samples collected from the area of the new campus of Taif University.

Science.gov (United States)

Sharshar, Taher; Hassan, H Ebrahim; Arida, Hassan A; Aydarous, Abdulkadir; Bazaid, Salih A; Ahmed, Mamdouh A

2013-01-01

The levels of radioactivity and heavy metals in soil, plant and groundwater samples collected from the area of the new campus of Taif University, Saudi Arabia, and its neighbouring areas have been determined. High-resolution gamma-ray spectroscopy was used for radioactivity measurements, and inductively coupled plasma atomic emission spectroscopy was used to determine the concentration of heavy metals. The means of (226)Ra, (228)Ra and (40)K concentrations in water samples collected from four wells were found to be 0.13 ± 0.03, 0.05 ± 0.03 and 1.3 ± 0.5 Bq l(-1), respectively. The means of (238)U, (226)Ra, (228)Ra ((232)Th for soil samples) and (40)K concentrations in wild plant and soil samples were found to be 3.7 ± 4.1, 8.8 ± 11.6, 3.8 ± 2.9 and 1025 ± 685, and 8.6 ± 3.4, 12.8 ± 3.4, 16.6 ± 7.1 and 618 ± 82 Bq kg(-1) dry weight (DW), respectively. The (137)Cs of artificial origin was also detected in soil samples with a mean concentration of 3.8 ± 2.2 Bq kg(-1) DW. Evaluating the results, it can be concluded that the concentrations of (238)U, (226)Ra, (232)Th and (40)K in soil samples fall within the world average. Furthermore, 19 trace and major elements in groundwater samples and 22 elements in soil and plant samples were determined. The sampling locations of soil can be classified into three groups (relatively high, medium and low polluted) according to their calculated metal pollution index using the contents of trace and major elements. A cluster analysis of the contents of radioactivity and trace element contents in soil samples shows the presence of two main distinct clusters of sampling locations.

Cost and Performance Report: Bioaugmentation for Aerobic Bioremediation of RDX-Contaminated Groundwater

Science.gov (United States)

2015-09-01

costs were also included. The addition of two extraction wells would not require an upgrade of the current granular activated carbon (GAC) treatment...transport properties, and RDX-degrading activity in UMCD aquifer material and groundwater. Phase II included a field-scale cell transport test conducted ...Accordingly, users may plan to conduct a field tracer test to confirm hydraulic connectivity between the injection and downgradient monitoring

Self-Organization in Aggregating Robot Swarms: A DW-KNN Topological Approach

KAUST Repository

Khaldi, Belkacem

2018-02-02

In certain swarm applications, where the inter-agent distance is not the only factor in the collective behaviours of the swarm, additional properties such as density could have a crucial effect. In this paper, we propose applying a Distance-Weighted K-Nearest Neighbouring (DW-KNN) topology to the behaviour of robot swarms performing self-organized aggregation, in combination with a virtual physics approach to keep the robots together. A distance-weighted function based on a Smoothed Particle Hydrodynamic (SPH) interpolation approach, which is used to evaluate the robot density in the swarm, is applied as the key factor for identifying the K-nearest neighbours taken into account when aggregating the robots. The intra virtual physical connectivity among these neighbours is achieved using a virtual viscoelastic-based proximity model. With the ARGoS based-simulator, we model and evaluate the proposed approach, showing various self-organized aggregations performed by a swarm of N foot-bot robots. Also, we compared the aggregation quality of DW-KNN aggregation approach to that of the conventional KNN approach and found better performance.

Effects of Bio-char on Soil Microbes in Herbicide Residual Soils

Directory of Open Access Journals (Sweden)

WANG Gen-lin

2015-10-01

Full Text Available Effects of biological carbon (bio-char on soil microbial community were studied by pot experiments simulating long residual herbicide residues in soil environment, which clarifed the improvement of biochar and its structural properties on soil microenvironment. The results showed that fungi and actinomycetes had the same effect tendency within 0~0.72 mg·kg-1 in clomazone residue which increased the role of stimulation with crop growth process prolonged, especially in high residue treatment, but strong inhibitory effect on bacteria community was occured early which returned to normal until sugar beet growth to fiftieth day. Soil fungi community decreased with bio-char adding, but had no significant difference with the control. When clomazone residue in soil was below 0.24 mg·kg-1, soil actinomycetes community was higher than control without bio-char, bacteria increased first and then reduced after adding carbon as below 0.12 mg·kg-1. Biochar was ‘deep hole’ structure containing C, O, S and other elements. The results showed that a certain concentration clomazone residue in soil would stimulate soil fungi and actinomycetes to grow. After adding the biochar, the inhibition effect of high herbicides residual on bacterial would be alleviated.

Is soil dressing a way once and for all in remediation of arsenic contaminated soils? A case study of arsenic re-accumulation in soils remediated by soil dressing in Hunan Province, China.

Science.gov (United States)

Su, Shiming; Bai, Lingyu; Wei, Caibing; Gao, Xiang; Zhang, Tuo; Wang, Yanan; Li, Lianfang; Wang, Jinjin; Wu, Cuixia; Zeng, Xibai

2015-07-01

The investigation of arsenic (As) re-accumulation in an area previously remediated by soil dressing will help in sustainable controlling the risks of As to local ecosystems and should influence management decisions about remediation strategies. In this study, As content in an area remediated by soil dressing and the possible As accumulation risk in agricultural products were investigated. The results indicated that after 7 years of agricultural activities, the average As content (24.6 mg kg(-1)) in surface soil of the investigated area increased by 83.6% compared with that (13.4 mg kg(-1)) in clean soil. Of the surface soil samples (n = 88), 21.6% had As levels that exceeded the limits of the Environmental Quality Standard for Soils of China (GB 15618-1995) and 98.9% of the surface soil samples with As contents exceeding that in clean soil was observed. Soil dressing might be not a remediation method once and for all in some contaminated areas, even though no significant difference in available As content was found between clean (0.18 mg kg(-1)) and surface (0.22 mg kg(-1)) soils. The foreign As in surface soil of the investigated area mainly specifically sorbed with soil colloid or associated with hydrous oxides of Fe and Al, or existed in residual fraction. The upward movement of contaminated soil from the deeper layers and the atmospheric deposition of slag particles might be responsible for the re-accumulation of As in the investigated area. Decreases in soil pH in the investigated soils and the fact that no plant samples had As levels exceeding the limits of the National Food Safety Standards for Contaminants of China (GB 2762-2012) were also observed.

Uptake of elements by fungi in the Forsmark area

Energy Technology Data Exchange (ETDEWEB)

Johanson, Karl J.; Nikolova, Ivanka; Taylor, Andy F.S. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology; Vinichuk, Mykhaylo M. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences

2004-10-01

Samples were collected in a forest ecosystem close to the Nuclear Power Plant at Forsmark, Sweden. The soil was fractioned in bulk soil, rhizosphere, soil-root interface and fungal mycelium. At the same sampling sites, fruit bodies of fungi were also collected. The concentration (mg/kg dw of soil) of K, Rb, Cs, P, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd, I, Hg, Pb, Ra, Th and U, were analysed in the various fractions using microspectrometry. The concentration of the stable potassium, rubidium and cesium in forest soil as well as in fungal compartment is discussed first and than the other 17 elements is discussed. Compared to bulk soil, rhizosphere was enriched with K, Rb and Cs by a factor 1.3, 1.7 and 1.5, and soil-root interface by factor 5.4, 2.6 and 1.0. Concentration of K, Rb and Cs was much higher in mycelium compared to bulk soil, indicating accumulation of these elements within fungi. The concentration ratios (CR) defined as mg/kg dw in mycelium divided by mg/kg dw in soil were found to be 4.5, 5.1 and 2.4 for K, Rb and Cs respectively. For fruit bodies of fungi, these ratios were about one order of magnitude higher than that for mycelium: 65, 3. 75.8 and 18.6 for K, Rb and Cs, respectively. In mycelium, only weak correlations were found between K and Rb uptake (r=0.33) and between K and Cs uptake (r=0.48). The concentrations of the elements in fruit bodies of fungi were species-dependent. Generally, fungi seemed to take up Rb more efficiently than K. Highest Cs concentrations were found in fruit bodies of Sarcodon imbricatus (25.1 mg/kg). Sarcodon imbricatus was found to accumulate K, Cs and especially Rb to greatest extent, followed by Cortinarius sp., and Suillus variegatus. Litter decomposing fungi Hypholoma capnoides and Collybia peronata showed relatively weak ability to accumulate K, Rb as well as Cs, compared to the mycorrhizal species. No correlation was found between concentration of K, Rb and Cs in fruit bodies of fungi and soil pH as well as

Uptake of elements by fungi in the Forsmark area

International Nuclear Information System (INIS)

Johanson, Karl J.; Nikolova, Ivanka; Taylor, Andy F.S.; Vinichuk, Mykhaylo M.

2004-10-01

Samples were collected in a forest ecosystem close to the Nuclear Power Plant at Forsmark, Sweden. The soil was fractioned in bulk soil, rhizosphere, soil-root interface and fungal mycelium. At the same sampling sites, fruit bodies of fungi were also collected. The concentration (mg/kg dw of soil) of K, Rb, Cs, P, Ca, Cr, Mn, Co, Ni, Cu, Zn, As, Sr, Cd, I, Hg, Pb, Ra, Th and U, were analysed in the various fractions using microspectrometry. The concentration of the stable potassium, rubidium and cesium in forest soil as well as in fungal compartment is discussed first and than the other 17 elements is discussed. Compared to bulk soil, rhizosphere was enriched with K, Rb and Cs by a factor 1.3, 1.7 and 1.5, and soil-root interface by factor 5.4, 2.6 and 1.0. Concentration of K, Rb and Cs was much higher in mycelium compared to bulk soil, indicating accumulation of these elements within fungi. The concentration ratios (CR) defined as mg/kg dw in mycelium divided by mg/kg dw in soil were found to be 4.5, 5.1 and 2.4 for K, Rb and Cs respectively. For fruit bodies of fungi, these ratios were about one order of magnitude higher than that for mycelium: 65, 3. 75.8 and 18.6 for K, Rb and Cs, respectively. In mycelium, only weak correlations were found between K and Rb uptake (r=0.33) and between K and Cs uptake (r=0.48). The concentrations of the elements in fruit bodies of fungi were species-dependent. Generally, fungi seemed to take up Rb more efficiently than K. Highest Cs concentrations were found in fruit bodies of Sarcodon imbricatus (25.1 mg/kg). Sarcodon imbricatus was found to accumulate K, Cs and especially Rb to greatest extent, followed by Cortinarius sp., and Suillus variegatus. Litter decomposing fungi Hypholoma capnoides and Collybia peronata showed relatively weak ability to accumulate K, Rb as well as Cs, compared to the mycorrhizal species. No correlation was found between concentration of K, Rb and Cs in fruit bodies of fungi and soil pH as well as

Evaluation of methyl bromide alternatives efficacy against soil-borne pathogens, nematodes and soil microbial community.

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Hongwei Xie

Full Text Available Methyl bromide (MB and other alternatives were evaluated for suppression of Fusarium spp., Phytophthora spp., and Meloidogyne spp. and their influence on soil microbial communities. Both Fusarium spp. and Phytophthora spp. were significantly reduced by the MB (30.74 mg kg-1, methyl iodide (MI: 45.58 mg kg-1, metham sodium (MS: 53.92 mg kg-1 treatments. MS exhibited comparable effectiveness to MB in controlling Meloidogyne spp. and total nematodes, followed by MI at the tested rate. By contrast, sulfuryl fluoride (SF: 33.04 mg kg-1 and chloroform (CF: 23.68 mg kg-1 showed low efficacy in controlling Fusarium spp., Phytophthora spp., and Meloidogyne spp. MB, MI and MS significantly lowered the abundance of different microbial populations and microbial biomass in soil, whereas SF and CF had limited influence on them compared with the control. Diversity indices in Biolog studies decreased in response to fumigation, but no significant difference was found among treatments in PLFA studies. Principal component and cluster analyses of Biolog and PLFA data sets revealed that MB and MI treatments greatly influenced the soil microbial community functional and structural diversity compared with SF treatment. These results suggest that fumigants with high effectiveness in suppressing soil-borne disease could significantly influence soil microbial community.

Vanadium bioavailability and toxicity to soil microorganisms and plants.

Science.gov (United States)

Larsson, Maja A; Baken, Stijn; Gustafsson, Jon Petter; Hadialhejazi, Golshid; Smolders, Erik

2013-10-01

Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200 mg V kg(-1)) of dissolved vanadate, and toxicity was measured with 2 microbial and 3 plant assays. The median effective concentration (EC50) thresholds of the microbial assays ranged from 28 mg added V kg(-1) to 690 mg added V kg(-1), and the EC50s in the plant assays ranged from 18 mg added V kg(-1) to 510 mg added V kg(-1). The lower thresholds were in the concentration range of the background vanadium in the untreated control soils (15-58 mg V kg(-1)). The vanadium toxicity to plants decreased with a stronger soil vanadium sorption strength. The EC50 values for plants expressed on a soil solution basis ranged from 0.8 mg V L(-1) to 15 mg V L(-1) and were less variable among soils than corresponding values based on total vanadium in soil. It is concluded that sorption decreases the toxicity of added vanadate and that soil solution vanadium is a more robust measure to determine critical vanadium concentrations across soils. © 2013 SETAC.

The effect of intrinsic soil properties on soil quality assessments

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Alessandro Samuel-Rosa

2013-10-01

Full Text Available The assessment of soil quality is based on indicators and indices derived from soil properties. However, intrinsic soil properties may interfere with other soil properties that vary under different land uses and are used to calculate the indices. The aim of this study was to assess the extent to which intrinsic soil properties (clay and iron oxide contents explain variable soil properties (sum of bases, potential acidity, organic carbon, total porosity, and bulk density under different land uses (native forest, no-tillage and conventional agriculture on small family farms in Southern Brazil. The results showed that the five properties evaluated can be included in soil quality assessments and are not influenced by the clay and iron oxide contents. It was concluded that for little weathered 1:1 and 2:1 phyllosilicate rich-soils, if the difference between the maximum and the minimum clay content under the different land uses is less than about 200 g kg-1 and the iron oxide content less than about 15 g kg-1, the physico-chemical soil properties in the surface layer are determined mostly by the land use.

De-oiled two-phase olive mill waste may reduce water contamination by metribuzin.

Science.gov (United States)

Peña, David; López-Piñeiro, Antonio; Albarrán, Ángel; Rato-Nunes, José Manuel; Sánchez-Llerena, Javier; Becerra, Daniel; Ramírez, Manuel

2016-01-15

The impact of de-oiled two-phase olive mill waste (DW) on the behavior of metribuzin in Mediterranean agricultural soils is evaluated, and the effects of the transformation of organic matter from this waste under field conditions are assessed. Four soils were selected and amended in the laboratory with DW at the rates of 2.5% and 5%. One of these soils was also amended in the field with 27 and 54 Mg ha(-1) of DW for 9 years. Significant increases in metribuzin sorption were observed in all the amended soils. In the laboratory, the 5% DW application rate increased the t1/2 values of metribuzin from 22.9, 35.8, 29.1, and 20.0 d for the original soils to 59.2, 51.1, 45.7, and 29.4d, respectively. This was attributable mainly to the inhibitory effect of the amendment on microbial activity. However, the addition of DW transformed naturally under field conditions decreased the persistence down to 3.93 d at the greater application rate. Both amendments (fresh and field-aged DW) significantly reduced the amount of metribuzin leached. This study showed that DW amendment may be an effective and sustainable management practice for controlling groundwater contamination by metribuzin. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical composition and non-volatile components of three wild edible mushrooms collected from northwest Tunisia

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ibtissem Kacem Jedidi

2016-04-01

Full Text Available In Tunisia, many people collect wild edible mushrooms as pickers for their own consumption. The present work aims at contributing to the determination of the chemical composition, non volatile components content (soluble sugars, free amino acids and minerals and trace elements of three popular Tunisian wild edible mushrooms species collected from the northwest of Tunisia (Agaricus campestris, Boletus edulis and Cantharellus cibarius.All investigated mushrooms revealed that these species are rich sources of proteins (123.70 – 374.10 g kg-1 dry weight (DW and carbohydrates (403.3 – 722.40 g kg-1 DW, and low content of fat (28.2 – 39.9 g kg-1 DW; the highest energetic contribution was guaranteed by C. cibarius (1542.71 kJ / 100 g. A. compestris (33.14 mg/g DW showed the highest concentration of essential amino acids. The composition in individual sugars was also determined, mannitol and trehalose being the most abundant sugars. C. cibarius revealed the highest concentrations of carbohydrates (722.4 g kg-1 DW and A. compestris the lowest concentration (403.3 g kg-1 DW. Potassium (K and sodium (Na are the most abundant minerals in analyzed samples (A. compestris showed the highest concentrations of K and Na, 49141.44 and 9263.886 µg/g DW respectively.

Cancer risk assessment of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in former agricultural soils of Hong Kong

International Nuclear Information System (INIS)

Man, Yu Bon; Lopez, Brenda Natalia; Wang, Hong Sheng; Leung, Anna Oi Wah; Chow, Ka Lai; Wong, Ming H.

2011-01-01

Highlights: → Electronic recycling site contain high concentrations of PCBs and PBDEs in Hong Kong. → Changing of agricultural land use to electronic waste recycling sites can increase potential cancer risk on human. → High levels of soil organic matter in soils render PBDEs and PCBs more resistant to degradation. - Abstract: The major objective of this study was to evaluate the carcinogenic risk posed to humans through PBDEs and PCBs of changing agricultural land use for recycling of e-waste and open burning of municipal waste. Nine locations were selected to represent 6 different types of land use such as e-waste dismantling workshop (EW (DW)) and e-waste open burning site (EW (OBS)). The total concentrations for PBDEs and PCBs, and the bioaccessibility of PCBs were determined using Soxhlet extraction and in vitro simulated gastric solution, respectively. Both total and bioaccessible concentrations were subsequently used to establish the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. It was found that very low cancer risk in all 6 types of different land use was caused by BDE-209. Nevertheless, at the 95th centile, the concentration of PCBs in EW (DW) and EW (OBS) indicate a low cancer risk to humans of 40 and 2.1 in a million, respectively, while the same was also observed for the bioaccessible PCBs in EW (DW) of 1.71 ± 2.96 in a million.

Cadmium accumulation characteristics of low-cadmium rice (Oryza sativa L.) line and F1 hybrids grown in cadmium-contaminated soils.

Science.gov (United States)

Li, Kun; Yu, Haiying; Li, Tingxuan; Chen, Guangdeng; Huang, Fu

2017-07-01

Cadmium (Cd) pollution has threatened severely to food safety and human health. A pot experiment and a field experiment were conducted to investigate the difference of Cd accumulation between rice (Oryza sativa L.) lines and F 1 hybrids in Cd-contaminated soils. The adverse effect on biomass of rice lines was greater than that of F 1 hybrids under Cd treatments in the pot experiment. The variations of Cd concentration among rice cultivars in different organs were smaller in stem and leaf, but larger in root and ear. Average proportion of Cd in root of F 1 hybrids was 1.39, 1.39, and 1.16 times higher than those of rice lines at the treatment of 1, 2, and 4 mg Cd kg -1 soil, respectively. Cd concentrations in ear of F 1 hybrids were significantly lower than rice lines with the reduction from 29.24 to 50.59%. Cd concentrations in brown rice of all F 1 hybrids were less than 0.2 mg kg -1 at 1 mg Cd kg -1 soil, in which Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be screened out as cadmium-safe cultivars (CSCs) for being safe even at 2 mg Cd kg -1 soil. C268A/YaHui2816 showed the lowest Cd concentration in root among F 1 hybrids, while Lu98A/YaHui2816 and 5406A/YaHui2816 showed lower capability of Cd translocation from root to shoot under Cd exposure, which eventually caused the lower Cd accumulation in brown rice. The lower level of Cd translocation contributed to reducing the accumulation of Cd in brown rice had been validated by the field experiment. Thus, Lu98A/YaHui2816, 5406A/YaHui2816, and C268A/YaHui2816 could be considered as potential CSCs to cultivate in Cd-contaminated soils (<2 mg Cd kg -1 soil).

Determination of heavy metals in two barbs, Barbus grypus and Barbus xanthopterus in Karoon and Dez Rivers, Khoozestan, Iran.

Science.gov (United States)

Mohammadi, Maryam; Askary Sary, Abolfazl; Khodadadi, Mojgan

2011-08-01

Cadmium, lead, nickel and mercury were contamination in gill, liver and muscle of B. grypus and B. xanthopterus in Karoon and Dez Rivers. Significant variations in metal values were evaluated using student's t test at p < 0.05. In B. grypus high levels of cadmium, lead, nickel and mercury were measured in gill (1.49, 2.25, 1.02 and 0.89 mg kg(-1) dw) except for mercury (1.06 mg kg(-1) dw) in B. grypus in Dez River was high in liver. In B. xanthopterus high levels of cadmium, lead, nickel and mercury were measured in gill (2.17, 2.91 and 1.43 mg kg(-1) dw) except for mercury (1.42 mg kg(-1) dw) high levels were measured in liver.

Occurrence of priority organic pollutants in the fertilizers, China

International Nuclear Information System (INIS)

Mo Cehui; Cai Quanying; Li Yunhui; Zeng Qiaoyun

2008-01-01

The use of large quantities of chemical fertilizers is usually associated with environmental problems. A lot of work has been done on the concentrations of heavy metals and radionuclides in chemical fertilizers, but little work has focused on the occurrence of semi-volatile organic compounds (SVOCs). In this study the occurrence of 43 SVOCs listed as priority pollutants in 22 widely used-fertilizers of China was determined by gas chromatography coupled with mass spectrometry. Twenty-six SVOCs were detected with different detection frequencies and concentrations. The most abundant compounds were phthalic acid esters (PAEs; ranging from 1.17 to 2795 μg kg -1 dry weight, d.w.) and nitroaromatics (up to 9765 μg kg -1 d.w.), followed by polycyclic aromatic hydrocarbons (PAHs; -1 d.w.) and halogenated hydrocarbons ( -1 d.w.). Chlorobenzenes and haloethers occurred generally at low concentrations. There are large variations in concentrations of various compounds in different fertilizers, and the total concentrations of each class of contaminants varied widely, too. The highest levels of sum concentration for 16 PAHs, for 6 PAEs and for nitroaromatics were found in organic fertilizer containing pesticide and soil amendments. Concentrations of SVOCs in coated fertilizers (the controlled release fertilizer with coating) were considerably higher than those in the corresponding fertilizers without coating. The occurrence frequencies of SVOCs in the straight fertilizers (containing only one of the major plant nutrients) were lower than in the other fertilizers

Sugammadex 4.0 mg kg-1 reversal of deep rocuronium-induced neuromuscular blockade

DEFF Research Database (Denmark)

Yu, Buwei; Wang, Xiangrui; Hansen, Søren Helbo

2014-01-01

Objective: Maintenance of deep Neuro Muscular Blockade (NMB) until the end of surgery may be beneficial in some surgical procedures. The selective relaxant binding agent sugammadex rapidly reverses deep levels of rocuronium-induced NMB. The purpose of this study was to evaluate the efficacy...... and safety of sugammadex 4.0 mg kg-1 for reversal of deep rocuronium-induced NMB in Chinese and Caucasian patients. Methods: This was an open-label, multicenter, prospective Phase III efficacy study in adult American Society of Anesthesiologists Class 1-3 patients scheduled for surgery under general...... anesthesia and requiring deep NMB. All patients received intravenous propofol and opioids for induction and maintenance of anesthesia, and a single intubation dose of rocuronium 0.6 mg/kg, with maintenance doses of 0.1-0.2 mg/kg as required. Sugammadex 4.0 mg/kg was administered after the last dose...

[Assessment of Soil Fluorine Pollution in Jinhua Fluorite Ore Areas].

Science.gov (United States)

Ye, Qun-feng; Zhou, Xiao-ling

2015-07-01

The contents of. soil total fluorine (TF) and water-soluble fluorine (WF) were measured in fluorite ore areas located in Jinhua City. The single factor index, geoaccumulation index and health risk assessment were used to evaluate fluorine pollution in soil in four fluorite ore areas and one non-ore area, respectively. The results showed that the TF contents in soils were 28. 36-56 052. 39 mg.kg-1 with an arithmetic mean value of 8 325.90 mg.kg-1, a geometric mean of 1 555. 94 mg.kg-1, and a median of 812. 98 mg.kg-1. The variation coefficient of TF was 172. 07% . The soil WF contents ranged from 0. 83 to 74. 63 mg.kg-1 with an arithmetic mean value of 16. 94 mg.kg-1, a geometric mean of 10. 59 mg.kg-1, and a median of 10. 17 mg.kg-1. The variation coefficient of WF was 100. 10%. The soil TF and WF contents were far higher than the national average level of the local fluorine epidemic occurrence area. The fluoride pollution in soil was significantly affected by human factors. Soil fluorine pollution in Yangjia, Lengshuikeng and Huajie fluorite ore areas was the most serious, followed by Daren fluorite ore area, and in non-ore area there was almost no fluorine pollution. Oral ingestion of soils was the main exposure route. Sensitivity analysis of model parameters showed that children's weight exerted the largest influence over hazard quotient. Furthermore, a significant positive correlation was found among the three kinds of evaluation methods.

Imaging children suffering from lymphoma: an evaluation of different {sup 18}F-FDG PET/MRI protocols compared to whole-body DW-MRI

Energy Technology Data Exchange (ETDEWEB)

Kirchner, Julian; Buchbender, Christian; Antoch, Gerald [University Dusseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Dusseldorf (Germany); Deuschl, Cornelius; Schweiger, Bernd; Forsting, Michael; Umutlu, Lale [University Hospital Essen, University of Duisburg-Essen, Department of Diagnostic and Interventional Radiology and Neuroradiology, Essen (Germany); Herrmann, Ken [University Hospital Essen, University of Duisburg-Essen, Department of Nuclear Medicine, Essen (Germany)

2017-09-15

The objectives of this study were to evaluate and compare the diagnostic potential of different PET/MRI reading protocols, entailing non-enhanced / contrast-enhanced and diffusion-weighted {sup 18}F-FDG PET/MR imaging and whole-body diffusion-weighted MRI for lesion detection and determination of the tumor stage in pediatric lymphoma patients. A total of 28 {sup 18}F-FDG PET/MRI datasets were included for analysis of four different reading protocols: (1) PET/MRI utilizing sole unenhanced T2w and T1w imaging, (2) PET/MRI utilizing additional contrast enhanced sequences, (3) PET/MR imaging utilizing unenhanced, contrast enhanced and DW imaging or (4) WB-DW-MRI. Statistical analyses were performed on a per-patient and a per-lesion basis. Follow-up and prior examinations as well as histopathology served as reference standards. PET/MRI correctly identified all 17 examinations with active lymphoma disease, while WB-DW-MRI correctly identified 15/17 examinations. Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 96%, 96.5%, 97%, 95%, and 96% for PET/MRI{sub 1}; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI{sub 2}; 97%, 96.5%, 97%, 96.5%, and 97% for PET/MRI{sub 3} and 77%, 96%, 96%, 78.5% and 86% for MRI-DWI. {sup 18}F-FDG PET/MRI is superior to WB-DW-MRI in staging pediatric lymphoma patients. Neither application of contrast media nor DWI leads to a noticeable improvement of the diagnostic accuracy of PET/MRI. Thus, unenhanced PET/MRI may play a crucial role for the diagnostic work-up of pediatric lymphoma patients in the future. (orig.)

The EDTA effect on phytoextraction of single and combined metals-contaminated soils using rainbow pink (Dianthus chinensis).

Science.gov (United States)

Lai, Hung-Yu; Chen, Zueng-Sang

2005-08-01

Rainbow pink (Dianthus chinensis), a potential phytoextraction plant, can accumulate high concentrations of Cd from metal-contaminated soils. The soils used in this study were artificially added with different metals including (1) CK: original soil, (2) Cd-treated soil: 10 mg Cd kg(-1), (3) Zn-treated soil: 100 mg Zn kg(-1), (4) Pb-treated soil: 1000 mg Pb kg(-1), (5) Cd-Zn-treated soil: 10 mg Cd kg(-1) and 100 mg Zn kg(-1), (6) Cd-Pb-treated soil: 10 mg Cd kg(-1) and 1000 mg Pb kg(-1), (7) Zn-Pb-treated soil: 100 mg Zn kg(-1) and 1000 mg Pb kg(-1), and (8) Cd-Zn-Pb-treated soil: 10 mg Cd kg(-1), 100 mg Zn kg(-1), and 1000 mg Pb kg(-1). Three concentrations of 2Na-EDTA solutions (0 (control), 2, and 5 mmol kg(-1) soil) were added to the different metals-treated soils to study the influence of applied EDTA on single and combined metals-contaminated soils phytoextraction using rainbow pink. The results showed that the Cd, Zn, Pb, Fe, or Mn concentrations in different metals-treated soil solutions significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). The metal concentrations in different metals-treated soils extracted by deionized water also significantly increased after applying 5 mmol EDTA kg(-1) (p<0.05). Because of the high extraction capacity of both 0.005 M DTPA (pH 5.3) and 0.05 M EDTA (pH 7.0), applying EDTA did not significantly increase the Cd, Zn, or Pb concentration in both extracts for most of the treatments. Applying EDTA solutions can significantly increase the Cd and Pb concentrations in the shoots of rainbow pink (p<0.05). However, this was not statistically significant for Zn because of the low Zn concentration added into the contaminated soils. The results from this study indicate that applying 5 mmol EDTA kg(-1) can significantly increase the Cd, Zn, or Pb concentrations both in the soil solution or extracted using deionized water in single or combined metals-contaminated soils, thus increasing the accumulated metals concentrations in

A glycolipid adjuvant, 7DW8-5, enhances CD8+ T cell responses induced by an adenovirus-vectored malaria vaccine in non-human primates.

Science.gov (United States)

Padte, Neal N; Boente-Carrera, Mar; Andrews, Chasity D; McManus, Jenny; Grasperge, Brooke F; Gettie, Agegnehu; Coelho-dos-Reis, Jordana G; Li, Xiangming; Wu, Douglass; Bruder, Joseph T; Sedegah, Martha; Patterson, Noelle; Richie, Thomas L; Wong, Chi-Huey; Ho, David D; Vasan, Sandhya; Tsuji, Moriya

2013-01-01

A key strategy to a successful vaccine against malaria is to identify and develop new adjuvants that can enhance T-cell responses and improve protective immunity. Upon co-administration with a rodent malaria vaccine in mice, 7DW8-5, a recently identified novel analog of α-galactosylceramide (α-GalCer), enhances the level of malaria-specific protective immune responses more strongly than the parent compound. In this study, we sought to determine whether 7DW8-5 could provide a similar potent adjuvant effect on a candidate human malaria vaccine in the more relevant non-human primate (NHP) model, prior to committing to clinical development. The candidate human malaria vaccine, AdPfCA (NMRC-M3V-Ad-PfCA), consists of two non-replicating recombinant adenoviral (Ad) vectors, one expressing the circumsporozoite protein (CSP) and another expressing the apical membrane antigen-1 (AMA1) of Plasmodium falciparum. In several phase 1 clinical trials, AdPfCA was well tolerated and demonstrated immunogenicity for both humoral and cell-mediated responses. In the study described herein, 25 rhesus macaques received prime and boost intramuscular (IM) immunizations of AdPfCA alone or with an ascending dose of 7DW8-5. Our results indicate that 7DW8-5 is safe and well-tolerated and provides a significant enhancement (up to 9-fold) in malaria-specific CD8+ T-cell responses after both priming and boosting phases, supporting further clinical development.

A glycolipid adjuvant, 7DW8-5, enhances CD8+ T cell responses induced by an adenovirus-vectored malaria vaccine in non-human primates.

Directory of Open Access Journals (Sweden)

Neal N Padte

Full Text Available A key strategy to a successful vaccine against malaria is to identify and develop new adjuvants that can enhance T-cell responses and improve protective immunity. Upon co-administration with a rodent malaria vaccine in mice, 7DW8-5, a recently identified novel analog of α-galactosylceramide (α-GalCer, enhances the level of malaria-specific protective immune responses more strongly than the parent compound. In this study, we sought to determine whether 7DW8-5 could provide a similar potent adjuvant effect on a candidate human malaria vaccine in the more relevant non-human primate (NHP model, prior to committing to clinical development. The candidate human malaria vaccine, AdPfCA (NMRC-M3V-Ad-PfCA, consists of two non-replicating recombinant adenoviral (Ad vectors, one expressing the circumsporozoite protein (CSP and another expressing the apical membrane antigen-1 (AMA1 of Plasmodium falciparum. In several phase 1 clinical trials, AdPfCA was well tolerated and demonstrated immunogenicity for both humoral and cell-mediated responses. In the study described herein, 25 rhesus macaques received prime and boost intramuscular (IM immunizations of AdPfCA alone or with an ascending dose of 7DW8-5. Our results indicate that 7DW8-5 is safe and well-tolerated and provides a significant enhancement (up to 9-fold in malaria-specific CD8+ T-cell responses after both priming and boosting phases, supporting further clinical development.

Analyzing AbrB-Knockout Effects through Genome and Transcriptome Sequencing of Bacillus licheniformis DW2

Science.gov (United States)

Shu, Cheng-Cheng; Wang, Dong; Guo, Jing; Song, Jia-Ming; Chen, Shou-Wen; Chen, Ling-Ling; Gao, Jun-Xiang

2018-01-01

As an industrial bacterium, Bacillus licheniformis DW2 produces bacitracin which is an important antibiotic for many pathogenic microorganisms. Our previous study showed AbrB-knockout could significantly increase the production of bacitracin. Accordingly, it was meaningful to understand its genome features, expression differences between wild and AbrB-knockout (ΔAbrB) strains, and the regulation of bacitracin biosynthesis. Here, we sequenced, de novo assembled and annotated its genome, and also sequenced the transcriptomes in three growth phases. The genome of DW2 contained a DNA molecule of 4,468,952 bp with 45.93% GC content and 4,717 protein coding genes. The transcriptome reads were mapped to the assembled genome, and obtained 4,102∼4,536 expressed genes from different samples. We investigated transcription changes in B. licheniformis DW2 and showed that ΔAbrB caused hundreds of genes up-regulation and down-regulation in different growth phases. We identified a complete bacitracin synthetase gene cluster, including the location and length of bacABC, bcrABC, and bacT, as well as their arrangement. The gene cluster bcrABC were significantly up-regulated in ΔAbrB strain, which supported the hypothesis in previous study of bcrABC transporting bacitracin out of the cell to avoid self-intoxication, and was consistent with the previous experimental result that ΔAbrB could yield more bacitracin. This study provided a high quality reference genome for B. licheniformis DW2, and the transcriptome data depicted global alterations across two strains and three phases offered an understanding of AbrB regulation and bacitracin biosynthesis through gene expression. PMID:29599755

Heavy metals (copper, cadmium, lead, mercury) in mute swans from Denmark

Energy Technology Data Exchange (ETDEWEB)

Elvestad, K.; Karlog, O.; Clausen, B.

1982-03-01

During the severe winter of 1978-79, large numbers of mute swans died in coastal areas of Denmark. Of these, 2111 were collected for examination. The analyses confirm previous findings of relatively high copper levels in mute swans (mean for 178 livers was 2680 mg/kg dry weight (Dw) and for 110 kidneys 34 mg/kg Dw) (Table I, Fig. 1). The copper content was not related to sex or age (Table II). The highest liver levels of copper were found in swans from Western Jutland. Cadmium was found at the same relatively low levels as recorded for waterfowl elsewhere (mean for 178 livers was 12 mg/kg Dw, for 110 kidneys 24 mg/kg Dw) (Table I, Fig. 2). The cadmium content was not sex-related, but it increased with age (Table II). The mean mercury content (liver) was 1.4 mg/kg Dw in the 10 birds analysed (Table I). The mean lead content was 15 mg/kg Dw in the 178 livers analysed and 31 mg/kg Dw in 110 sternum (Table I and Fig. 3). The lead content was not sex-related. In sternum, but not in livers, it was related to age (Table II). One third of the swans were found lead-contaminated probably after ingestion of lead pellets. None of the swans carried high levels of both copper, cadmium, and lead (Table III).

Biological diversity of Salix taxa in Cu, Pb and Zn phytoextraction from soil.

Science.gov (United States)

Mleczek, Mirosław; Rutkowski, Paweł; Goliński, Piotr; Kaczmarek, Zygmunt; Szentner, Kinga; Waliszewska, Bogusława; Stolarski, Mariusz; Szczukowski, Stefan

2017-02-01

The aim of the study was to estimate the efficiency of copper (Cu), lead (Pb) and zinc (Zn) phytoextraction by 145 Salix taxa cultivated in an area affected by industrial activity. Survivability and biomass of plants were also analyzed. The highest Cu, Pb and Zn content in shoots was 33.38 ± 2.91 (S. purpurea × viminalis 8), 24.64 ± 1.97 (S. fragilis 1) and 58.99 ± 4.30 (S. eriocephala 7) mg kg -1 dry weight, respectively. In the case of unwashed leaves, the highest content of these metals was 135.06 ± 8.14 (S. purpurea 26), 67.98 ± 5.27 (S. purpurea 45) and 142.56 ± 12.69 (S. alba × triandra 2) mg kg -1 dw, while in washed leaves it was 106.02 ± 11.12 (S. purpurea 45), 55.06 ± 5.75 (S. purpurea 45) and 122.87 ± 12.33 (S. alba × triandra 2) mg kg -1 dw, respectively. The differences between the highest and lowest values for Cu, Pb and Zn were 545%, 20500% and 535% in shoots; 2692%, 2560% and 7500% in unwashed leaves; and 3286%, 2221% and 6950% in washed leaves, respectively. S. acutifolia was able to effectively accumulate all three metals jointly, producing shoots that were well developed in both length and diameter when compared with the other tested willows-an ability that would suggest its high suitability for practical application.

Effects of uranium on soil microbial biomass carbon, enzymes, plant biomass and microbial diversity in yellow soils

International Nuclear Information System (INIS)

Yan, X.; Zhang, Y.; Luo, X.; Yu, L.

2016-01-01

We conducted an experiment to investigate the effects of uranium (U) on soil microbial biomass carbon (MBC), enzymes, plant biomass and microbial diversity in yellow soils under three concentrations: 0 mg kg"-"1 (T1, control), 30 mg kg"-"1 (T2) and 60 mg kg"-"1 (T3). Under each treatment, elevated U did not reduce soil MBC or plant biomass, but inhibited the activity of the soil enzymes urease (UR), dehydrogenase (DH) and phosphatase (PHO). The microbial diversity was different, with eight dominant phyla in T1 and six in T2 and T3. Furthermore, Proteobacteria and material X were both detected in each treatment site (T1, T2 and T3). Pseudomonas sp. was the dominant strain, followed by Acidiphilium sp. This initial study provided valuable data for further research toward a better understanding of U contamination in yellow soils in China. (authors)

Humic substances as a washing agent for Cd-contaminated soils.

Science.gov (United States)

Meng, Fande; Yuan, Guodong; Wei, Jing; Bi, Dongxue; Ok, Yong Sik; Wang, Hailong

2017-08-01

Cost-effective and eco-friendly washing agents are in demand for Cd contaminated soils. Here, we used leonardite-derived humic substances to wash different types of Cd-contaminated soils, namely, a silty loam (Soil 1), a silty clay loam (Soil 2), and a sandy loam (Soil 3). Washing conditions were investigated for their effects on Cd removal efficiency. Cadmium removal was enhanced by a high humic substance concentration, long washing time, near neutral pH, and large solution/soil ratio. Based on the tradeoff between efficiency and cost, an optimum working condition was established as follows: humic substance concentration (3150 mg C/L), solution pH (6.0), washing time (2 h) and a washing solution/soil ratio (5). A single washing removed 0.55 mg Cd/kg from Soil 1 (1.33 mg Cd/kg), 2.32 mg Cd/kg from Soil 2 (6.57 mg Cd/kg), and 1.97 mg Cd/kg from Soil 3 (2.63 mg Cd/kg). Cd in effluents was effectively treated by adding a small dose of calcium hydroxide, reducing its concentration below the discharge limit of 0.1 mg/L in China. Being cost-effective and safe, humic substances have a great potential to replace common washing agents for the remediation of Cd-contaminated soils. Besides being environmentally benign, humic substances can improve soil physical, chemical, and biological properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphorus status and sorption characteristics of some calcareous soils of Hamadan, western Iran

Science.gov (United States)

Jalali, Mohsen

2007-10-01

Phosphorus (P) application in excess of plant requirement may result in contamination of drinking water and eutrophication of surface water bodies. The phosphorous buffer capacity (PBC) of soil is important in plant nutrition and is an important soil property in the determination of the P release potential of soils. Phosphorus sorption greatly affects both plant nutrition and environmental pollution. For better and accurate P fertilizer recommendations, it is necessary to quantify P sorption. This study was conducted to investigate available P and P sorption by calcareous soils in a semi-arid region of Hamadan, western Iran. The soil samples were mainly from cultivated land. Olsen’s biocarbonate extractable P (Olsen P) varied among soils and ranged from 10 to 80 mg kg-1 with a mean of 36 mg kg-1. Half of the soils had an Olsen P > 40 mg kg-1 and >70% of them had a concentration >20 mg kg-1, whereas the critical concentration for most crops is potato (44 kg kg-1) fields than in dry-land wheat farming (24 mg kg-1), pasture (30 mg kg-1), and wheat (24 mg P kg-1) fields. A marked increase in fertilizer P rates applied to agricultural soils has caused P to be accumulated in the surface soil. Phosphate sorption curves were well fitted to the Freundlich equation. The standard P requirement (SPR) of soils, defined as the amount of P sorbed at an equilibrium concentration of 0.2 mg l-1 ranged from 4 to 102 mg kg-1. Phosphorus buffer capacity was relatively high and varied from 16 to 123 l kg-1 with an average of 58 l kg-1. In areas of intensive crop production, continual P applications as P fertilizer and farmyard manure have been used at levels exceeding crop requirements. Surface soil accumulations of P are high enough that loss of P in surface runoff and a high risk for P transfer into groundwater have become priority management concerns.

Mechanical and chemical responses of low-velocity impacted RDX and HMX explosive powders

Science.gov (United States)

Wu, Yanqing; Guo, Hongfu; Huang, Fenglei; Bao, Xiaowei; Explosion; damage Team

2017-06-01

The experimental analyses of mechanical and chemical responses of RDX and HMX particles were performed based on the optimized drop-weight experimental system equipped with the High-Speed Camera (HSC). It has been found that Jetting phenomenon observed by HSC is the result of the energy released by gaseous products, which push the pulverized or melted explosives to splash radially. Jetting is the only and the most obvious difference between reactive and inert particles prior to combustion so that jetting can be regarded as the sign of ignition. Area expansion velocity, jetting velocity, and flame propagation velocity have been estimated via image processing, making it possible to characterize mechanical deformation and violence of reaction of each stage. Hot-spots coalescence promotes flame propagation whose velocity reflects the violence of deflagration reaction. Jetting appearance time can be used to determine time-to-ignition more accurately than other ways. For RDX, molten phase plays an important role to the formation of the hot-spots. Multiple particles experienced more severe burning reactions than an individual particle. China National Nature Science Foundation (11572045), ``Science Challenging Program'' (JCKY2016212A501),opening fund from Safety ammunition research and Development Center (RMC2015B03).

[Soil soluble organic matter, microbial biomass, and enzyme activities in forest plantations in degraded red soil region of Jiangxi Province, China].

Science.gov (United States)

Jiang, Yu-mei; Chen, Cheng-long; Xu, Zhi-hong; Liu, Yuan-qiu; Ouyang, Jing; Wang, Fang

2010-09-01

Taking the adjacent 18-year-old pure Pinus massoniana pure forest (I), P. massoniana, Liquidamber fomosana, and Schima superba mixed forest (II), S. superba pure forest (III), L. fomosana (IV) pure forest, and natural restoration fallow land (CK) in Taihe County of Jiangxi Province as test sites, a comparative study was made on their soil soluble organic carbon (SOC) and nitrogen (SON), soil microbial biomass C (MBC) and N (MBN), and soil urease and asparaginase activities. In 0-10 cm soil layer, the pool sizes of SOC, SON, MBC, and MBN at test sites ranged in 354-1007 mg x kg(-1), 24-73 mg x kg(-1), 203-488 mg x kg(-1), and 24-65 mg x kg(-1), and the soil urease and asparaginase activities were 95-133 mg x kg(-1) x d(-1) and 58-113 mg x kg(-1) x d(-1), respectively. There were significant differences in the pool sizes of SOC, SON, MBC, and MBN and the asparaginase activity among the test sites, but no significant difference was observed in the urease activity. The pool sizes of SOC and SON were in the order of IV > CK > III > I > II, those of MBC and MBN were in the order of CK > IV > III > I > II, and asparaginase activity followed the order of IV > CK > III > II > I. With the increase of soil depth, the pool sizes of SOC, SON, MBC, and MBN and the activities of soil asparaginase and urease decreased. In 0-20 cm soil layer, the SOC, SON, MBC, MBN, total C, and total N were highly correlated with each other, soil asparaginase activity was highly correlated with SOC, SON, TSN, total C, total N, MBC, and MBN, and soil urease activity was highly correlated with SON, TSN, total C, MBC and MBN.

Effects of hydrocarbon contamination on a free living marine nematode community: Results from microcosm experiments

Energy Technology Data Exchange (ETDEWEB)

Mahmoudi, E.; Essid, N.; Beyrem, H.; Hedfi, A.; Boufahja, F.; Aissa, P. [Laboratoire de Biosurveillance de l' Environnement, Zarzouna (Tunisia). Faculte des Sciences de Bizerte; Vitiello, P. [Centre d' Oceanologie de Marseille (France)

2005-11-15

Anthropogenic inputs of crude and refined petroleum hydrocarbons into the sea require knowledge of the effects of these contaminants on the receiving assemblages of organisms. A microcosm experiment was carried out to study the influence of diesel on a free living nematode community of a Tunisian lagoon. Sediments were contaminated by diesel that ranged in concentration from 0.5 to 20 mg diesel kg{sup -1} dry weight (dw), and effects were examined after 90 days. Gradual changes in community structure were revealed depending on the quantity of diesel administrated. In the medium (1 mg diesel kg{sup -1} and 5 mg diesel kg{sup -1} (dw)) and high (10 mg diesel kg{sup -1}, 15 mg diesel kg{sup -1} and 20 mg kg{sup -1} (dw)) treated microcosms, most univariate measures, including diversity and species richness, decreased significantly with increasing level of diesel contamination whereas nematode assemblage from the low treated microcosm (0.5 mg diesel kg{sup -1} (dw)) remained unaffected. Results from multivariate analyses of the species abundance data demonstrated that responses of nematode species to the diesel treatments were varied: Chaetonema sp. was eliminated at all doses tested and seemed to be intolerant species to diesel contamination; Pomponema sp. and Oncholaimus campylocercoides were significantly affected at all diesel contamination levels but they were not eliminated, these species were categorized as 'diesel-sensitive'; Hypodontolaimus colesi, Daptonema trabeculosum and Daptonema fallax which significantly increased respectively at 0.5, 1 and 5 mg diesel kg{sup -1} (dw) concentrations and appeared to be 'opportunistic' species at these doses whereas Marylynnia stekhoveni which increased at all high doses (10, 15 and 20 mg diesel kg{sup -1} (dw)) seemed to be a 'diesel-resistant' species. (author)

Facilitated transport of diuron and glyphosate in high copper vineyard soils.

Science.gov (United States)

Dousset, Sylvie; Jacobson, Astrid R; Dessogne, Jean-Baptiste; Guichard, Nathalie; Baveye, Philippe C; Andreux, Francis

2007-12-01

The fate of organic herbicides applied to agricultural fields may be affected by other soil amendments, such as copper applied as a fungicide. The effect of copper on the leaching of diuron and glyphosate through a granitic and a calcareous soil was studied in the laboratory using sieved-soil columns. Each soil was enriched with copper sulfate to obtain soil copper concentrations of 125, 250, 500, and 1000 mg kg(-1). Glyphosate leaching was influenced by soil pH and copper concentration, whereas diuron leaching was not. In the calcareous soil, glyphosate leaching decreased as copper levels increased from 17 mg kg(-1) (background) to 500 mg kg(-1). In the granitic soil, glyphosate leaching increased as copper levels increased from 34 mg kg(-1) (background) to 500 mg kg(-1). The shapes of the copper elution curves in presence of glyphosate were similar to shapes of the glyphosate curves, suggesting the formation of Cu-glyphosate complexes that leach through the soil. Soil copper concentration does not influence diuron leaching. In contrast, increasing copper concentrations reduces glyphosate leaching through calcareous soils, and conversely, increases glyphosate leaching through granitic soils. Our findings suggest that the risk of groundwater contamination by glyphosate increases in granitic soils with elevated copper concentrations.

Investigations of Chemical and Biological Treatment Options for the Attenuation of Hexahydro-1,3,5-trinitro-1,3,5-triazine Contamination in Groundwater at Los Alamos, New Mexico

Science.gov (United States)

Heerspink, B. P.; Wang, D.; Ware, D.; Marina, O.; Perkins, G.; WoldeGabriel, G. W.; Goering, T.; Boukhalfa, H.

2017-12-01

High-explosive compounds including hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) were used extensively in weapons research and testing at Los Alamos National Laboratory (LANL) in Los Alamos, NM. Liquid effluents containing RDX released at LANL's Technical Area 16 (TA-16) resulted in the contamination of alluvial, perched-intermediate, and regional groundwater bodies. Past investigations have shown persistent RDX contamination in the perched-intermediate zone located between 225 to 311 m below ground surface, where transport studies have shown that RDX and its degradation products transport conservatively. In this study, we compared RDX degradation by chemical treatments using reduction by sodium dithionite, oxidation by potassium permanganate, and alkaline hydrolysis by carbonate/bicarbonate buffering, with microbial degradation under biostimulated conditions. The experiments were conducted using groundwater and sediments representative of the contaminated aquifer beneath TA-16. Batch testing showed that all chemical treatments degraded RDX very rapidly, with half-lives ranging from 50 minutes to 22 hours. Comparatively, RDX degradation in biostimulated reactors under strict anaerobic conditions was significantly slower, with half-lives of about 3 weeks. Results from column experiments with chemically treated sediments deviated from the results of the batch testing. Dithionite treated sediments reduced RDX with no breakthrough observed before clogging occurred at 50 pour volumes. Treatments by oxidation using potassium permanganate, and hydrolysis under buffered alkaline conditions, were less effective with complete RDX breakthrough after 2 pore volumes. No known degradation products were observed in the column effluents. RDX degradation in biostimulated columns was very effective initially for both treatments. However, the column biostimulated with safflower oil clogged very rapidly. The column biostimulated with molasses was very effective when molasses was

The Effect of Light Casings on the Blast Parameters from a Spherical Charge of RDX/TNT 60/40

National Research Council Canada - National Science Library

Bishop, Valerie J; James, D. J

1968-01-01

.... High speed cine films were taken of the fireball growth. Peak overpressure and impulse enhancement over the values from an uncased RDX/TNT charge were obtained only from the thickest lead casing...

Sorption, mobility, and fate of 1,4,7,8-tetrachlorodibenzo-p-dioxin in soils

Energy Technology Data Exchange (ETDEWEB)

Larsen, G.; Hakk, H. [USDA ARS Biosciences Research Lab., Fargo (United States); Fan, Z.; Casey, F. [North Dakota State Univ., Fargo (United States)

2004-09-15

Most dioxins are released into the environment through low temperature combustion processes, which include waste incineration and metal refining. Incineration of medical and municipal wastes in the early 1990s was estimated to generate 0.7g -5 kg dioxin Toxic Equivalents (TEQ)/yr and 2-3 kg TEQ/yr of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) emissions, respectively. Governmental regulatory controls on waste incinerators have resulted in an annual decrease of dioxins/furans emissions from 13.5 kg TEQ/yr to 2.8 kg TEQ/yr from 1987 to 1995. Recently backyard burning of household waste has been shown to produce more PCDDs/PCDFs per mass burned than a typical modern municipal waste incinerator and has been estimated to account for 22% of the dioxin emissions in North America from 1996-1997. These combustion processes result in direct deposition of dioxins on soil. While degradation studies of PCDDs/PCDFs have been conducted on contaminated soils, little is known about the sorption, transport, and fate of dioxins in various soil types. 1,4,7,8- Tetrachlorodibenzo-p-dioxin (1478-TCDD) was also found to be a significant congener of the dioxins in ball clay.7 Ball clay had been used as an anti-caking agent in soybean meal of animal feed but its use has subsequently been discontinued. The main goal of this study was to identify the fate and transport of 1478-TCDD in various soils and sand through the use of laboratory batch and soil column experiments.

Effect of biochar produced at different pyrolysis temperature on the soil respiration of abandoned mine soil

Science.gov (United States)

Kim, Yong Seong; Kim, Juhee; Hwang, Wonjae; Hyun, Seunghun

2015-04-01

Contaminated soils near an abandoned mine site included the high acidic mine tailing have received great interest due to potential risk to human health, because leachable elements in low pH continuously release from mine site soil with ground water and precipitation event. Biochar, which is the obtained pyrolysis process of biomass, is used as a soil amendments and carbon storage. Especially, many researchers report that the biochar application to soil show increasing soil pH, CEC, adsorption capacity of various elements, as well as, enhanced microbial activity. Therefore, biochar application to contaminated soil near abandoned mine site is expected to have a positive effects on management of these site and soils through the decreased leachability of contaminants. However, effects of biochar application to these site on the soil respiration, as a common measure of soil health, are poorly understood. The objective of this study is to evaluate the effects of biochar application to abandoned mine site soil on the microbial activity with soil respiration test. Biochar was obtained from giant Miscanthus in a slow pyrolysis process (heating rate of 10° C min-1 and N2 gas flow rate of 1.2 L min-1) at the temperature of 400° C (BC4) and 700° C (BC7), respectively. All biochar samples were prepared with grinding and sieving for particle size control (150~500μm). Soil sample was collected from abandoned mine site at Korea (36° 58'N, 128° 10'E). Main contaminants of this soil were As (12.5 g kg-1), Pb (7.3 g kg-1), and Zn (1.1 g kg-1). Biochars were applied (5% by dry weight) to the soil (final mixture weight were 800g), and then moisture contents were adjusted to 100% field capacity (-0.33 bar) in the respirometer with vacuum pump. CO2 efflux of each samples was continuously assessed using continuous aeration system (air flow rate 25 cc min-1) using air cylinder during 130hr (at 20° C and darkness condition). The CO2 emitted from the samples were carried to the

Influence of soil properties and phosphate addition on arsenic uptake from polluted soils by velvetgrass (Holcus lanatus).

Science.gov (United States)

Lewińska, K; Karczewska, A

2013-01-01

Four kinds of soil material were used in a pot experiment with velvetgrass (Holcus lanatus). Two unpolluted soils: sand (S) and loam (L) were spiked with sodium arsenite (As II) and arsenate (As V), to obtain total arsenic (As) concentrations of 500 mg As kg(-1). Two other soils (ZS I, ZS III), containing 3320 and 5350 mg As kg(-1), were collected from Zloty Stok where gold and arsenic ores were mined and processed for several centuries. The effects of phosphate addition on plants growth and As uptake were investigated. Phosphate was applied to soils in the form of NH4H2PO4 at the rate 0.2 g P/kg. Average concentrations of arsenic in the shoots of velvetgrass grown in spiked soils S and L without P amendment were in the range 18-210 mg As kg(-1) d.wt., whereas those in plants grown on ZS I and ZS II soils were considerably lower, and varied in the range 11-52 mg As kg(-1) d.wt. The addition of phosphate caused a significant increase in plant biomass and therefore the total amounts of As taken up by plants, however, the differences in As concentrations in the shoots of velvetgrass amended and non-amended with phosphate were not statistically significant.

Effects of Straw Return in Deep Soils with Urea Addition on the Soil Organic Carbon Fractions in a Semi-Arid Temperate Cornfield.

Science.gov (United States)

Zou, Hongtao; Ye, Xuhong; Li, Jiaqi; Lu, Jia; Fan, Qingfeng; Yu, Na; Zhang, Yuling; Dang, Xiuli; Zhang, Yulong

2016-01-01

Returning straw to deep soil layers by using a deep-ditching-ridge-ploughing method is an innovative management practice that improves soil quality by increasing the soil organic carbon (SOC) content. However, the optimum quantity of straw return has not been determined. To solve this practical production problem, the following treatments with different amounts of corn straw were investigated: no straw return, CK; 400 kg ha-1 straw, S400; 800 kg ha-1 straw, S800; 1200 kg ha-1 straw, S1200; and 1600 kg ha-1 straw, S1600. After straw was returned to the soil for two years, the microbial biomass C (MBC), easily oxidized organic C (EOC), dissolved organic C (DOC) and light fraction organic C (LFOC) content were measured at three soil depths (0-10, 10-20, and 20-40 cm). The results showed that the combined application of 800 kg ha-1 straw significantly increased the EOC, MBC, and LFOC contents and was a suitable agricultural practice for this region. Moreover, our results demonstrated that returning straw to deep soil layers was effective for increasing the SOC content.

Accumulation of oil and grease in soils irrigated with greywater and their potential role in soil water repellency.

Science.gov (United States)

Travis, Micheal J; Weisbrod, Noam; Gross, Amit

2008-05-01

The potential impact of oil and grease (O and G) to soils irrigated with greywater (GW) was investigated. Greywater streams were sampled and analyzed for O and G content, along with corresponding GW-irrigated soils. Untreated kitchen GW averaged 200 mg L(-1) O and G, over an order of magnitude more than other GW streams. GW-irrigated soils showed O and G accumulation of up to 200 mg kg(-l) within the first 20-cm of depth. To determine the potential effects of such O and G accumulation on water movement in soil, capillary rise and water drop penetration time (WDPT) experiments were conducted. The results showed up to 60% decrease in capillary rise when sand containing 250 mg kg(-1) O and G was used. Interestingly, no additional reduction in capillary rise was observed at concentrations above 250 mg kg(-1). WDPT was observed to increase linearly with increased O and G content, up to 1000 mg kg(-1). This work demonstrated that O and G in GW used for irrigation can accumulate in soil and may lead to a significant reduction in the soils ability to transmit water.

Pilot scale aided-phytoremediation of a co-contaminated soil.

Science.gov (United States)

Marchand, Charlotte; Mench, Michel; Jani, Yahya; Kaczala, Fabio; Notini, Peter; Hijri, Mohamed; Hogland, William

2018-03-15

A pilot scale experiment was conducted to investigate the aided-phytoextraction of metals and the aided-phytodegradation of petroleum hydrocarbons (PHC) in a co-contaminated soil. First, this soil was amended with compost (10% w/w) and assembled into piles (Unp-10%C). Then, a phyto-cap of Medicago sativa L. either in monoculture (MS-10%C) or co-cropped with Helianthus annuus L. as companion planting (MSHA-10%C) was sown on the topsoil. Physico-chemical parameters and contaminants in the soil and its leachates were measured at the beginning and the end of the first growth season (after five months). In parallel, residual soil ecotoxicity was assessed using the plant species Lepidium sativum L. and the earthworm Eisenia fetida Savigny, 1826, while the leachate ecotoxicity was assessed using Lemna minor L. After 5months, PH C10-C40, PAH-L, PAH-M PAH-H, Pb and Cu concentrations in the MS-10%C soil were significantly reduced as compared to the Unp-10%C soil. Metal uptake by alfalfa was low but their translocation to shoots was high for Mn, Cr, Co and Zn (transfer factor (TF) >1), except for Cu and Pb. Alfalfa in monoculture reduced electrical conductivity, total organic C and Cu concentration in the leachate while pH and dissolved oxygen increased. Alfalfa co-planting with sunflower did not affect the extraction of inorganic contaminants from the soil, the PAH (M and H) degradation and was less efficient for PH C10-C40 and PAH-L as compared to alfalfa monoculture. The co-planting reduced shoot and root Pb concentrations. The residual soil ecotoxicity after 5months showed a positive effect of co-planting on L. sativum shoot dry weight (DW) yield. However, high contaminant concentrations in soil and leachate still inhibited the L. sativum root DW yield, earthworm development, and L. minor growth rate. Copyright © 2017 Elsevier B.V. All rights reserved.

Are levels of perfluoroalkyl substances in soil related to urbanization in rapidly developing coastal areas in North China?

International Nuclear Information System (INIS)

Meng, Jing; Wang, Tieyu; Wang, Pei; Zhang, Yueqing; Li, Qifeng; Lu, Yonglong; Giesy, John P.

2015-01-01

Concentrations of 13 perfluoroalkyl substances (PFASs) were quantified in 79 surface soil samples from 17 coastal cities in three provinces and one municipality along the Bohai and Yellow Seas. The ∑PFASs concentrations ranged from less than limitation of quantification (LOQ) to 13.97 ng/g dry weight (dw), with a mean of 0.98 ng/g dw. The highest concentration was observed along the Xiaoqing River from Shandong province, followed by that from the Haihe River in Tianjin (10.62 ng/g dw). Among four regions, ∑PFASs concentrations decreased in the order of Tianjin, Shandong, Liaoning and Hebei, which was consistent with levels of urbanization. Fluorine chemical industries allocated in Shandong and Liaoning played important roles in terms of point emission and contamination of PFASs, dominated by perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Intensive anthropogenic activities involved in urbanization possibly resulted in increasing releases of PFASs from industrial and domestic sources. - Highlights: • PFASs were detected in the soil of rapidly developing coastal regions in China. • PFAS concentrations ranged from LOQ to 13.97 ng/g dw, with a mean of 0.98 ng/g dw. • Higher concentrations of PFASs correspond to higher levels of urbanization. • Existence of fluorine industry induced PFAS pollutions dominated by PFOA and PFOS. • Intensive urbanization caused increasing emission of industrial and domestic PFASs. - Among urban, suburban and rural areas in the coasts, soils from urban area showed high degrees of PFASs contamination with the existence of industrial emissions dominated by PFOA and PFOS

Measured soil water concentrations of cadmium and zinc in plant pots and estimated leaching outflows from contaminated soils

DEFF Research Database (Denmark)

Holm, P.E.; Christensen, T.H.

1998-01-01

Soil water concentrations of cadmium and zinc were measured in plant pots with 15 contaminated soils which differed in origin, texture, pH (5.1-7.8) and concentrations of cadmium (0.2-17 mg Cd kg(-1)) and zinc (36-1300 mg Zn kg(-1)). The soil waters contained total concentrations of 0.5 to 17 mu g...... to 0.1% per year of the total soil content of cadmium and zinc. The measured soil water concentrations of cadmium and zinc did not correlate linearly with the corresponding soil concentrations but correlated fairly well with concentrations measured in Ca(NO(3))(2) extracts of the soils and with soil...... water concentrations estimated from soil concentrations and pH. Such concentration estimates may be useful for estimating amounts of cadmium and zinc being leached from soils....

Correlation between soil chemical characteristics and soil-borne mycoflora in cucumber tunnels

International Nuclear Information System (INIS)

Qudsia, H.; Javaid, A.; Mahmood, R.; Akhtar, N.

2017-01-01

Twelve soil samples were collected from fields of cucumber (Cucumis sativus L.) tunnels from various localities of Lahore and Shekhupura districts, Pakistan. Soil samples were analyzed for various characteristics viz. pH, EC/sub e/, organic matter, nitrogen (N), phosphorus (P) and potassium (K). Soil mycoflora was isolated using dilution plate method. Soil pH, EC/sub e/, organic matter, N, P and K were in the range of 7.42-8.13, 107-2520 (meu S cm-1), 0.98-1.40%, 0.039-0.070%, 7-357 mg kg/sup -1/ and 88-946 mg kg/sup -1/ in different soil samples, respectively. A total of 18 fungal species belonging to 10 genera viz. Aspergillus, Alternaria, Cladosporium, Drechslera, Emericella, Fusarium, Mortierella, Mucor, Penicillium and Sclerotium were isolated from various soil samples. Saprophytic fungi were more prevalent than pathogenic ones. Number of colonies of saprophytic fungi ranged from 360-2754 g/sup -1/ soil in different samples. In contrast, number of pathogenic fungal colonies were limited to 1-234 g/sup -1/ soil. Number of colonies of pathogenic fungi were positively and significantly correlated with soil organic matter and nitrogen contents. This study concludes that high nitrogen and organic matter in cucumber tunnels favour population of pathogenic fungi. (author)

Immobilizer-assisted management of metal-contaminated agricultural soils for safer food production.

Science.gov (United States)

Kim, Kwon-Rae; Kim, Jeong-Gyu; Park, Jeong-Sik; Kim, Min-Suk; Owens, Gary; Youn, Gyu-Hoon; Lee, Jin-Su

2012-07-15

Production of food crops on metal contaminated agricultural soils is of concern because consumers are potentially exposed to hazardous metals via dietary intake of such crops or crop derived products. Therefore, the current study was conducted to develop management protocols for crop cultivation to allow safer food production. Metal uptake, as influenced by pH change-induced immobilizing agents (dolomite, steel slag, and agricultural lime) and sorption agents (zeolite and compost), was monitored in three common plants representative of leafy (Chinese cabbage), root (spring onion) and fruit (red pepper) vegetables, in a field experiment. The efficiency of the immobilizing agents was assessed by their ability to decrease the phytoavailability of metals (Cd, Pb, and Zn). The fruit vegetable (red pepper) showed the least accumulation of Cd (0.16-0.29 mgkg(-1) DW) and Pb (0.2-0.9 mgkg(-1) DW) in edible parts regardless of treatment, indicating selection of low metal accumulating crops was a reasonable strategy for safer food production. However, safer food production was more likely to be achievable by combining crop selection with immobilizing agent amendment of soils. Among the immobilizing agents, pH change-induced immobilizers were more effective than sorption agents, showing decreases in Cd and Pb concentrations in each plant well below standard limits. The efficiency of pH change-induced immobilizers was also comparable to reductions obtained by 'clean soil cover' where the total metal concentrations of the plow layer was reduced via capping the surface with uncontaminated soil, implying that pH change-induced immobilizers can be practically applied to metal contaminated agricultural soils for safer food production. Copyright © 2012 Elsevier Ltd. All rights reserved.

Role of extrinsic arbuscular mycorrhizal fungi in heavy metal-contaminated wetlands with various soil moisture levels.

Science.gov (United States)

Zheng, S; Wang, C; Shen, Z; Quan, Y; Liu, X

2015-01-01

This study presents an efficient heavy metal (HM) control method in HM-contaminated wetlands with varied soil moisture levels through the introduction of extrinsic arbuscular mycorrhizal fungi (AMF) into natural wetland soil containing indigenous AMF species. A pot culture experiment was designed to determine the effect of two soil water contents (5-8% and 25-30%), five extrinsic AMF inoculants (Glomus mosseae, G. clarum, G. claroideum, G. etunicatum, and G. intraradices), and HM contamination on root colonization, plant growth, and element uptake of common reed (Phragmites australis (Cav.) Trin. ex Steudel) plantlets in wetland soils. This study showed the prevalence of mycorrhizae in the roots of all P. australis plantlets, regardless of extrinsic AMF inoculations, varied soil moisture or HM levels. It seems that different extrinsic AMF inoculations effectively lowered HM concentrations in the aboveground tissues of P. australis at two soil moisture levels. However, metal species, metal concentrations, and soil moisture should also be very important factors influencing the elemental uptake performance of plants in wetland ecosystems. Besides, the soil moisture level significantly influenced plant growth (including height, and shoot and root dry weight (DW)), and extrinsic AMF inoculations differently affected shoot DW.

A Method for Manufacturing Oncological Phantoms for the Quantification of 18F-FDG PET and DW-MRI Studies

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Francesca Gallivanone

2017-01-01

Full Text Available The aim of this work was to develop a method to manufacture oncological phantoms for quantitation purposes in 18F-FDG PET and DW-MRI studies. Radioactive and diffusion materials were prepared using a mixture of agarose and sucrose radioactive gels. T2 relaxation and diffusion properties of gels at different sucrose concentrations were evaluated. Realistic oncological lesions were created using 3D-printed plastic molds filled with the gel mixture. Once solidified, gels were extracted from molds and immersed in a low-radioactivity gel simulating normal background tissue. A breast cancer phantom was manufactured using the proposed method as an exploratory feasibility study, including several realistic oncological configurations in terms of both radioactivity and diffusion. The phantom was acquired in PET with 18F-FDG, immediately after solidification, and in DW-MRI the following day. Functional volumes characterizing the simulated BC lesions were segmented from PET and DW-MRI images. Measured radioactive uptake and ADC values were compared with gold standards. Phantom preparation was straightforward, and the time schedule was compatible with both PET and MRI measurements. Lesions appeared on 18F-FDG PET and DW-MRI images as expected, without visible artifacts. Lesion functional parameters revealed the phantom’s potential for validating quantification methods, in particular for new generation hybrid PET-MRI systems.

Polycyclic aromatic hydrocarbons and pesticides in soil of Vojvodina

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Pucarević Mira M.

2004-01-01

Full Text Available The paper deals with several groups of compounds that represent the most frequent pollutants of soil in the world. The paper also reviews results of long-term studies conducted at the Institute of Field and Vegetable Crops in Novi Sad on the residues of pesticides and polycyclic aromatic hydrocarbons (PAHs in the soil of the Vojvodina Province. The analyzed samples have been found to contain residues of persistent pesticides and their metabolites lindane and its metabolites 6,20 μg/kg, alachlor 3,56 μg/kg, aldrin 2,3 μg/kg, heptachlor epoxide 0,99 μg/kg, chlordane 3,82 μg/kg, DDT and its metabolites 10,77 μg/kg, dieldrin 2,04 μg/kg, endrin 3,57 μg/kg and endrin aldehyde 1,36 μg/kg. Soil samples from Novi Sad municipality contained 53,69 μg/kg of DDT and its metabolites. The values of atrazine ranged from 0,0005 to 0,8 mg/kg. The values of PAHs were 6,64 mg/kg in industrial soil, 4,93 mg/kg in agricultural soil, and 4,55 mg/kg and 5,48 mg/kg in the Novi Sad municipality. The lowest value, 0.83 mg/kg, was found for nonagricultural/nonindustrial soils.

Rimsulfuron in Soil: Effects on Microbiological Properties under Varying Soil Conditions

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Ljiljana Radivojević

2011-01-01

Full Text Available The effects of rimsulfuron a sulfonylurea herbicide on the growth and activity of soil microorganisms under laboratory conditions was investigated in two soils. The application rates were: 0.2, 2.0 and 20.0 mg a.i kg-1 soil. The lowest concentration tested was the label rate (0.2 mg a.i kg-1, and the other two were ten and hundred timeshigher. No adverse effects on microbiological processes were observed for the label rate. Decrease in microbial biomass carbon, dehydrogenase activity, fungi and bacteria in comparison with untreated control, were found at higher rates. The magnitude of these effects were generally slight and transitory.

Soil organic carbon pools and stocks in permafrost-affected soils on the tibetan plateau.

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Corina Dörfer

Full Text Available The Tibetan Plateau reacts particularly sensitively to possible effects of climate change. Approximately two thirds of the total area is affected by permafrost. To get a better understanding of the role of permafrost on soil organic carbon pools and stocks, investigations were carried out including both discontinuous (site Huashixia, HUA and continuous permafrost (site Wudaoliang, WUD. Three organic carbon fractions were isolated using density separation combined with ultrasonic dispersion: the light fractions (1.6 g cm(-3 of mineral associated organic matter (MOM. The fractions were analyzed for C, N, and their portion of organic C. FPOM contained an average SOC content of 252 g kg(-1. Higher SOC contents (320 g kg(-1 were found in OPOM while MOM had the lowest SOC contents (29 g kg(-1. Due to their lower density the easily decomposable fractions FPOM and OPOM contribute 27% (HUA and 22% (WUD to the total SOC stocks. In HUA mean SOC stocks (0-30 cm depth account for 10.4 kg m(-2, compared to 3.4 kg m(-2 in WUD. 53% of the SOC is stored in the upper 10 cm in WUD, in HUA only 39%. Highest POM values of 36% occurred in profiles with high soil moisture content. SOC stocks, soil moisture and active layer thickness correlated strongly in discontinuous permafrost while no correlation between SOC stocks and active layer thickness and only a weak relation between soil moisture and SOC stocks could be found in continuous permafrost. Consequently, permafrost-affected soils in discontinuous permafrost environments are susceptible to soil moisture changes due to alterations in quantity and seasonal distribution of precipitation, increasing temperature and therefore evaporation.

Influence of flooding and metal immobilising soil amendments on availability of metals for willows and earthworms in calcareous dredged sediment-derived soils

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Vandecasteele, Bart, E-mail: bart.vandecasteele@ilvo.vlaanderen.b [Institute for Agricultural and Fisheries Research (ILVO), Scientific Institute of the Flemish Government, Burg. Van Gansberghelaan 109, B-9820 Merelbeke (Belgium); Du Laing, Gijs [Ghent University, Department of Applied Analytical and Physical Chemistry, Coupure 653, B-9000 Ghent (Belgium); Lettens, Suzanna [Research Institute for Nature and Forest (INBO), Scientific Institute of the Flemish Government, Gaverstraat 4, B-9500 Geraardsbergen (Belgium); Jordaens, Kurt [Department of Biology, Evolutionary Biology Group, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Tack, Filip M.G. [Ghent University, Department of Applied Analytical and Physical Chemistry, Coupure 653, B-9000 Ghent (Belgium)

2010-06-15

Soil amendments previously shown to be effective in reducing metal bioavailability and/or mobility in calcareous metal-polluted soils were tested on a calcareous dredged sediment-derived soil with 26 mg Cd/kg dry soil, 2200 mg Cr/kg dry soil, 220 mg Pb/kg dry soil, and 3000 mg Zn/kg dry soil. The amendments were 5% modified aluminosilicate (AS), 10% w/w lignin, 1% w/w diammonium phosphate (DAP, (NH{sub 4}){sub 2}HPO{sub 4}), 1% w/w MnO, and 5% w/w CaSO{sub 4}. In an additional treatment, the contaminated soil was submerged. Endpoints were metal uptake in Salix cinerea and Lumbricus terrestris, and effect on oxidation-reduction potential (ORP) in submerged soils. Results illustrated that the selected soil amendments were not effective in reducing ecological risk to vegetation or soil inhabiting invertebrates, as metal uptake in willows and earthworms did not significantly decrease following their application. Flooding the polluted soil resulted in metal uptake in S. cinerea comparable with concentrations for an uncontaminated soil. - Some soil amendments resulted in higher metal uptake by earthworms and willows than when the polluted soil was not amended but submersion of the polluted soil resulted in reduced Cd and Zn uptake in Salix cinerea.

Phenols in anaerobic digestion processes and inhibition of ammonia oxidising bacteria (AOB) in soil

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Leven, Lotta; Nyberg, Karin; Korkea-aho, Lena; Schnuerer, Anna

2006-01-01

This study focuses on the presence of phenols in digestate from seven Swedish large-scale anaerobic digestion processes and their impact on the activity of ammonia oxidising bacteria (AOB) in soil. In addition, the importance of feedstock composition and phenol degradation capacity for the occurrence of phenols in the digestate was investigated in the same processes. The results revealed that the content of phenols in the digestate was related to the inhibition of the activity of AOB in soil (EC 5 = 26 μg phenols g -1 d.w. soil). In addition, five pure phenols (phenol, o-, p-, m-cresol and 4-ethylphenol) inhibited the AOB to a similar extent (EC 5 = 43-110 μg g -1 d.w. soil). The phenol content in the digestate was mainly dependent on the composition of the feedstock, but also to some extent by the degradation capacity in the anaerobic digestion process. Swine manure in the feedstock resulted in digestate containing higher amounts of phenols than digestate from reactors with less or no swine manure in the feedstock. The degradation capacity of phenol and p-cresol was studied in diluted small-scale batch cultures and revealed that anaerobic digestion at mesophilic temperatures generally exhibited a higher degradation capacity compared to digestion at thermophilic temperature. Although phenol, p-cresol and 4-ethylphenol were quickly degraded in soil, the phenols added with the digestate constitute an environmental risk according to the guideline values for contaminated soils set by the Swedish Environmental Protection Agency. In conclusion, the management of anaerobic digestion processes is of decisive importance for the production of digestate with low amounts of phenols, and thereby little risks for negative effects of the phenols on the soil ecosystem

Inorganic Phosphorus Fractions and Their Relationships with Soil Characteristics of Selected Calcareous Soils of Fars Province

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abolfazl azadi

2017-01-01

sequential fractionation scheme was preformed according to the method described by Jiang and Gu (1989. Olsen-P fraction that was extracted by NaHCO3 (Olsen and Sommers 1982 was regarded as P-availability index. Also, Total-P by perchloric acid (HClO4 digestion (Sparks; 1996 and organic P were determined.. All of the extraction procedures were performed in duplicate and the amounts of P were colorimetrically measured in the supernatants by the ascorbic acid method of Murphy and Riley (1962.The relationships between forms of P and some of the soil properties were established using correlation method. Results and Discussion: The chemical data of the soils showed that soils were calcareous with CCE range between 9.94 to 74.27 % ( average 51.10% and pH range between 7.02 to 8.36 (average 7.85. Also, the amounts of CEC were between 5.35 to 29.39 cmol (+ kg-1(average 16.68 cmol (+ kg-1. The results showed a wide range in content of Phosphorus fractions. The amount of total Phosphate ranged from 301.87 to 1458.68 mg kg-1 with an average of 626.63 mg kg-1 . Calcium Phosphate ranged from 147.83 to 666.90 mg kg-1 with an average of 324.79 mg kg-1, that comprised 85 and 52 percent of inorganic and total Phosphorus, respectively. The amount of Fe-P ranged from 0.38 to 59.18 mg kg-1 with an average of 7.56 mg kg-1 that comprised 13.64 and 8.34 percent of inorganic and total Phosphorus, respectively. Also, the amount of Al-P ranged from 20.49 to 123.09 mg kg-1 with an average of 52.28 mg kg-1that comprised 1.97 and 1.21 percent of inorganic and total Phosphorus, respectively. The results of correlation study showed that available Phosphorus was significantly correlated with Ca2-P, Ca8-P, Al-P, Ca10-P, and Pt (total phosphorus. So, in calcareous soils, awareness of soil properties and phosphorus fractions and their relationships are important for evaluation of phosphorous status in soil and understanding of soil chemistry that influence soil fertility. Conclusion: The relative abundance of